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Anomalies of the intrinsic muscles in camptodactyly
Vol. 8, No.5, Part I September 1983
117. 118.
119.
120.
121.
Replantation and revascularization surgery in children. Hand 12: 12-24, 1980 Leung PC, Kok LC: Transplantation of the second toe to the hand. J Bone Joint Surg [Am] 62:990-6, 1980 Moberg E: Objective methods for determining sensibility in the hand. J Bone Joint Surg [Br] 40:454-66, 1958 Jabaley ME, Bums JE, Orcutt BS, Bryant WM: Comparison of histologic and functional recovery after peripheral nerve repair. J HAND SURG I: 119-30, 1976 Edshage S: Experience with clinical methods of testing sensation after peripheral nerve surgery. In Jewett DL, McCarroll HR, editors: Nerve repair and regeneration. Clinical and experimental basis. St. Louis, 1980, The C V Mosby Co, pp 244-9 Orner GE Jr: Sensation and sensibility in the upper extremity. Clin Orthop 104: 30-6, 1974
Sensibility and function with microvascular free tissue transfer
122. Orner EG Jr: Evaluation and reconstruction of the forearm and hand after acute peripheral nerve injuries. J Bone Joint Surg [ Am] 50: 1454-78, 1968 123. Craig JC: Pictorial and abstract cutaneous displays. In Geldard FA, editor: Conference on vibrotactile communication. Austin, Texas, 1974, Psychonomic Society, pp 78-83 124. Dyck PJ: Quantitation of cutaneous sensation in man. In Dyck PF, Thomas PK, Lambert EH, editors: Peripheral neuropathy. Philadelphia, 1975, W B Saunders Co, pp 465-79 125. Dellon AL: The moving two-point discrimination test: clinical evaluation of the quickly adapting fiber Ireceptor system. J HAND SURG 3:474-81, 1978
Anomalies of the intrinsic muscles in camptodactyly Our observations support the view of Millesi that camptodactyly is due to an imbalance between the flexor and extensor forces acting upon the proximal interphalangeal joint. In 21 consecutive operations the insertion of the lumbrical muscle was abnormal. The muscle inserted into either the superficialis tendon (in three cases), the capsule of the metacarpophalangeal joint (in 15), or the extensor expansion of the adjacent finger (in four). The fourth palmar interosseous muscle was examined in the last 10 patients and was abnormal in five. It was absent in two patients, small in one, and inserted into the extensor expansion of the ring finger in two patients. Therefore, it is suggested that camptodactyly is an intrinsic minus deformity. It follows that treatment should consist of soft tissue release, as necessary, to correct the flexion deformity, followed by a tendon transfer to restore intrinsic action and maintain correction of the deformity. (J HAND SURG 8:531.44, 1983.)
Robert M. McFarlane, M.D., G. Ian Curry, M.B., and H. Brian Evans, M.D.,
London, Ontario, Canada
Camptodactyly is a common defonnity of the small finger. An individual with a slight flexion contracture is not likely to seek medical advice but a contracture of 30° or more at the proximal interphalan· geal (PIP) joint will cause sufficient concern, if not a functional disability, for that person to inquire about From the Department of Surgery, Division of Plastic Surgery of Victoria Hospital, and the Faculty of Medicine of the University of Western Ontario. Received for publication Feb. 10, 1982; accepted in revised form Sept. 21, 1982. Reprint requests: Robert M. McFarlane, M.D., Dept. of Surgery, Victoria Hospital, 391 South St., London, Ontario, N6A 405, Canada.
treatment. The results of operation for camptodactyly have been unsatisfactory so that most surgeons are reo luctant to attempt correction of the defonnity. 1, 2 Patients with a mild contracture are usually advised to accept the defonnity. For more severe contractures, a variety of operations have been advised on the assumption that camptodactyly results from a variety of causes. Clinical series In January 1978, while operating on a patient with camptodactyly, we noticed for the first time the insertion of the lumbrical muscle of the small finger (lumbrical IV) into the superficialis tendon of the same THE JOURNAL OF HAND SURGERY
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Table I. Twenty-one consecutive patients with an anomaly of the lumbrical muscle Patient No.
Age (years)
Sex
Finger
Preop PIP ROM
2
Jan. 78 Aug. 78 Feb. 78
14 IS 16
M M F
LV LV RV
501110 75/95 551105
3
Feb. 78
4 5
II 12
Apr. 78 June 78 Mar. 79 June 81 July 78 June 79 Aug. 81 June 79 Sept. 79 Oct. 79 Dec. 79 Nov. 81 Jan. 80 Jan. 80
13 15 44 16 17 19 14 IS 17 16 10 6 13 IS 9 12
M M F F F F F F F M F F F F F F
RV RV LV RV RV RV RV RV RV RV LV LV LV LV RV RV
301100 70/95 701100 301105 501105 60/105 451105 60/90 65/95 701100 30/95 601100 551105 60/95 401100 551100
13
Apr. 80
12
F
RV
35/95
14
June 80
21
F
LV
651110
IS
Mar. 81
16
M
16 17 18
May 81 June 81 May 82
I 35 13
F F F
RV RIV RV LV RV
351105 30/105 501100 501105 651105
19
July 82
14
F
LV
75/95
20
July 82
13
F
LV
401100
21
Aug. 82
3
M
RV
55/100
6
7 8 9 10
Treated
Lumbrical insertion
Superf. V. Capsule MP Capsule MP Capsule MP Capsule MP
Capsule MP
Extensor IV Superf. V Capsule MP Capsule MP Capsule MP Capsule MP No palmar interos. Capsule MP No palmar interos. Capsule MP Small palmar interos. Capsule MP Extensor III Extensor IV Capsule MP Superf. V Capsule MP Palmar interos. to extensor IV Capsule MP Palmar interos. to extensor IV Extensor IV
PIP procedure
Manipulation Osteotomy prox. phal. None None Excise superf. slips Palmar plate release None Scar excision Palmar plate release None Scar excision Scar excision Palmar plate release None Palmar plate release None Palmar plate release None None
None
Palmar plate release
None Palmar plate release None* Palmar plate release None
None
None*
ROM = range of motion. *Superficialis V attached proximally to palmar aponeurosis without a muscle belly. Excised.
finger (superficialis V). Including this patient, we have found an abnormal insertion of lumbrical IV in a series of21 consecutive operations. Lumbrical IV was always present and always originated from the profundus tendon of the small finger, but the insertion varied. As listed in Table I, the most common anomaly was that the muscle fibers inserted into the flexor tendon sheath and capsule of the metacarpophalangeal (MP) joint without a tendon of insertion (15 fingers). In four fingers lumbrical IV had a tendinous insertion into the
extensor expansion of the adjacent finger. In three fingers lumbrical IV inserted into superficialis V. In patient 12 of this series we observed that palmar interosseous IV was absent. We had not examined this muscle before but have examined it at all subsequent operations. Palmar interosseous IV was absent in patient 13, was very small in patient 14, and it attached to the extensor expansion of the ring finger in patients 19 and 20. Therefore, an anomaly of palmar interosseous IV was noted in five of the last 10 patients in this series.
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Anomalies of intrinsic muscles in camptodactyly
Postop splinting (months)
ROM
To distal crease of palm
6 2 6
75/95 45/65 15/90
4.5 em 4.0 em 3.0 em
5 1 6 6 6 3 24 6 4 1 2 6 3 2 6
70/95 -10/60 34/45 501105 601105 15/40 60/90 65/95 40/85 55/95 25/95 75/80 60/95 25175 251100 201105
Superf. V to extensor
4
45/95
Superf. V to extensor
3
Superf. IV to extensor IV and V
2
Superf. IV to extensor Superf. IV to extensor Superf. V to extensor
1 6
Tendon transfer Superf. V to extensor Superf. V to extensor Superf. V to extensor Shorten transfer Superf. V to extensor Superf. V to extensor Superf. V to central slip Superf. IV to central slip Superf. V to extensor None Superf. IV to central slip None* None Superf. V to extensor Superf. V to extensor Superf. IV to extensor Lumbrical to extensor Superf. V to extensor
Postop PIP
em em em em em em em em em em em em em em em em
Comment Failure of transfer and loss of flexion Improved Decreased DIP flexion pre and postop Overeorreeted by transfer Failure of transfer Failure of transfer Failure of transfer Failure of transfer Improved Failure without tendon transfer Failure without tendon transfer Failure to transfer Failure of transfer Improved Improved Improved
0.0 em
Failure of transfer
0.0 em 0.0 em 0.0 em 2.5 em
Improved
Lost to followup 01105 01105 40/90 45/90
Failure of transfer Failure of transfer Superf. V used as transfer because normal muscle confirmed in fore-
arm
Superf. IV to extensor
Superf. V extensor
0.0 3.0 4.0 0.0 0.0 4.0 3.5 2.0 1.0 0.0 0.0 2.0 1.5 1.5 0.0 0.0
533
3
Superf. IV to extensor
Because the lumbrical muscle was always abnormal and the palmar interosseous muscle was occasionally abnormal we believe that there is reasonable evidence to suggest that the deformity of camptodactyly is due to the absence of intrinsic action. The appearance of the finger is in keeping with an intrinsic minus deformity because the MP joint is always in hyperextension in addition to the PIP joint being flexed (see Figs. 1, A, 3, C, 4, A, and 5, A). If the deformity is due to the absence of normal intrinsic action then the appropriate treatment would be to restore this action by tendon transfer. Furthermore, a tendon transfer should be per-
formed early, when the joint contracture is minimal and secondary changes in soft tissues and bone have not occurred. This paper documents the clinical features and the surgical findings in a series of 21 patients with camptodactyly. Also we will describe an operation that deals, not only with the primary problems of intrinsic muscle abnormality, but also with the secondary changes in skin, tendon, and joint structures. Some features of these patients are listed in Table I. The youngest patient was 1 year old and the oldest 44, but 13 of 21 were between 12 and 16 years old. It was
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Table II. Correction of deformity by superficialis release and transfer Patient No.
Preop passive extension at PIP
Correct contr. by release of super! V
Restore balance by transfer of super! V
No No Yes No No No No No No No No Yes No No Yes No No No No No No
No Yes Yes No Yes Yes No Not divided No Yes Not divided Yes Yes No Not divided Not divided No No No No No
No Yes Yes* No No No Excisedt Not transferred No No Not transferred:j: Yes No No Not transferred Not transferred Excisedt
2 3
4 5 6 7 8 9 10 II
12 13
14 15 16 17 18 19 20 21
Restore balance by transfer superj. IV
Result Failed Improved Improved Failed
Yes Yes Failed, no transfer Failed Failed, no transfer Yes
Yes No No
Good Good Failed Failed Good Failed Failed
Excised Excisedt
'Overcorrected by transfer. tNo proximal muscle belly. tLumbrical muscle transferred alone.
not possible to determine the age of onset of the contracture. The majority of patients were female (16 of 21). This may be because girls are more concerned about the appearance of their fingers. Most patients had bilateral deformities with one side more severe than the other, and this side was operated on. To date, no patient has requested operation on the opposite finger! The degrees of contracture ranged between 30° and 75°. No patient was offered an operation with a contracture of less than 30°. As listed in Table II, only three of 21 patients had full passive correction of the PIP joint contracture preoperatively. The conditions of each of these patients were improved by operation. We were unable to demonstrate correction of the deformity by flexon of the wrist (to relax the superficialis tendon) in any of these patients. Illustrative cases Patient No.1. C. T., a 14-year-old boy, had 50° of contracture at the PIP joint and full flexion preoperatively (Fig. I, A). X-ray films of the PIP joint were normal. The flexor tendons were exposed over the PIP joint and looked normal. With manipulation the joint was extended so that no surgical release of the soft tissues about the joint was performed. The flexor tendons were inspected proximal to the tendon sheath and muscle fibers were noted on superficialis V (Fig. 1, B). More proximal dissection revealed that these fibers were
lumbrical IV and originated in the normal way from the profundus tendon. Superficialis V was divided just proximal to the vincula longa and withdrawn. The lumbrical was removed. The tendon was passed deep to the transverse metacarpal ligament and sutured to the radial side of the extensor expansion. The appearance of the finger at the completion of the transfer is shown in Fig. 1, C. Postoperatively the boy did not cooperate with the splinting program. Within 2 months the contracture was 55° and by 6 months it was 75°. At a second operation an osteotomy of the proximal phalanx corrected the deformity to the extent shown in Fig. 1, D and E. Comment. This was the first patient in the series and the abnormality of the lumbrical muscle was noted only because it was so obvious. However, even this anomaly would have been missed if the incision had not extended well into the palm. The transfer of superficialis V to the extensor expansion failed either because the patient did not cooperate or because superficialis V did not have independent action and therefore was unsatisfactory as a tendon transfer. Patient No.3. J. S., a 13-year-old boy, had 30° of contracture at the PIP joint. At operation lumbrical IV was found attached to the flexor tendon sheath and the capsule of the MP joint, although a few rudimentary tendinous fibers were attached to the extensor expansion (Fig. 2, A). The muscle was resected. The tendon sheath was opened over the PIP joint. Because he had passive extension at the joint no soft tissue release was needed. Superficialis V was sectioned and withdrawn. It was passed deep to the transverse metacarpalligament and sutured to the radial side of the extensor expansion.
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Fig. 1. Patient No.1. A, The typical deformity of camptodactyly with hyperextension at the MP joint and flexion at the PIP joint. B, In the most proximal part of the wound lumbrical IV can be seen to insert into superficialis V just as the tendon enters the flexor tendon sheath (arrow). C, After transfer of superficialis V the MP joint hyperextension is gone and the PIP joint is more extended. D and E, The range of flexion and extension after an osteotomy of the proximal phalanx. Note that the MP joint hyperextension has recurred. Postoperatively extension at the PIP joint was maintained while the patient was wearing a splint, but it was lost when the splint was removed for varying periods during the day. One year after operation the deformity was 70°. At a second operation, the distal slips of superficialis V were found adherent within the tendon sheath. Upon their removal and lysis of the profundus tendon the PIP joint straightened. The superficialis tendon transfer was too lax and was adherent (Fig. 2, B and C). The tendon was lysed and
shortened by 2 cm. There was good proximal tonus of the tendon. Postoperatively, PIP joint extension was maintained, but he had difficulty regaining flexion and also developed a mallet finger deformity. The result 2 years later is shown in Fig. 2, D and E. Comment. This patient shows the usual anomaly of lumbrical IV. Almost all of the muscle fibers attached to structures around the MP joint. It is not unusual to see some muscle fibers extend to the radial side of the extensor expan-
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Fig. 2. Patient No.3. A, Anomalous insertion of lumbrical IV into the flexor tendon sheath and the capsule ofthe MP joint. Most of the muscle fibers have been released from their insertion, leaving a few on a rudimentary tendon that proceeded to the extensor expansion (arrow) . Band C, The superficialis transfer failed to extend the PIP joint, even though full passive extension was present as shown at the second operation . D and E, The result after shortening the transfer. He has full extension at the PIP joint, but lacks full finger flexion and has a mallet finger. sion, or to have a delicate tendon extend to the expansion, but when traction is applied to the body of the muscle there is no transmission to the expansion . This patient also illustrates the problem of balance in performing the tendon transfer. At the first operation the transfer was too loose whereas it was tightened excessively at the second operation . Patient No.5. 1. W ., a 16-year-old girl , had only 30° of contracture, but was concerned about the appearance of her finger. At operation, about one third of the muscle fibers were
found attached to the tendon sheath at the level of the MP joint, whereas the remaining fibers entered a small but normal looking tendon (Fig. 3, A) . The muscle was detached from the tendon sheath and sutured to the small lumbrical tendon . Upon division of superficialis V the PIP joint straightened. The tendon had normal tonus and was sutured to the lumbrical tendon (Fig. 3, B). In spite of splinting, the contracture recurred and within 3 months was 60°. At a second operation the cause of the contracture, as in the
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Fig. 3. Patient No . 5. A, Anomalous insertion of lumbrical IV into the flexor tendon sheath . The muscle belly is supported by a probe and the level of the MP joint is marked with black ink on the flexor tendon sheath. The free edge of the extensor expansion is held by forceps. About one third of the muscle inserted into the tendon sheath. The remainder inserted by way of a tendon into the extensor expansion . B, Superficialis V and some of the lumbrical muscle were sutured to the lumbrical tendon at its insertion into the extensor expansion. C and D, Appearance of the finger after two operations. There is slight MP joint hyperextension and 55° of PIP joint flexion. The patient had developed a nodule of Dupuytren's disease in the palm and tight fascia to the ring and long fingers that caused 15° of flexion contracture at the MP joint of both fingers. E and F, The range of flexion and extension 6 months after superficialis I V transfer. previous case, was adherence of the superficialis slips . Upon excision of these slips the joint straightened. The superficiaiis transfer was adherent to surrounding tissue. It was freed and rerouted to the dorsum of the finger where it was sutured to the central slip of the extensor expansion. Postoperatively
extension was maintained only as long as the finger was splinted continuously. Within 6 months the patient had 55° of flexion contracture (Fig. 3, C) . At this time she complained that she was unable to fully extend the ring and long fingers and had noted some lumps in her palm (Fig. 3, D). These
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Fig. 4. Patient No. 12. A, The typical appearance of camptodactyly. B, Lumbrical IV is held with the smooth retractor. The entire muscle inserts into the flexor tendon sheath. C, Lumbrical IV has been sutured to superficialis V, which is to be transferred to the extensor expansion. D, The position of the finger at the completion of the transfer. The MP joint is slightly flexed and the PIP joint extended. E, The final result showing full extension of the small finger. were typical of Dupuytren's disease. A third operation was performed. A nodule of Dupuytren's disease was removed. The lumbrical tendon and superficialis transfer were adherent to surrounding tissue and therefore removed. It was necessary to incise the palmar plate of the PIP joint to gain extension at the joint. Superficialis IV was transferred and sutured to the middle slip of the extensor tendon at the site where the superficialis V had been attached. Also, the extensor tendon was lysed because of adhesions. A Kirschner wire held the PIP
joint in extension for 3 weeks and then a splint was applied. It was removed for varying periods, on the advice of the therapist, in order to regain flexion and maintain extension. Three months after operation there was no evidence of Dupuytren's disease and she could fully extend the ring and long fingers. The range of movement at the PIP joint of the small finger was 25/35. At 6 months it was 15/40 with full passive extension, but she still was unable to fully flex the finger (Fig. 3, E and F).
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Fig. 5. Patient No. 15. A, Camptodactyly of the small, ring, and long fingers with the deformity decreasing in severity towards the radial side of the hand. B, After transfer of superficialis IV to the small and ring fingers he gained full extension, and also retained full flexion. Comment. The insertion of the lumbrical muscle was abnormal, but part of the muscle entered a normal tendon. It may be that the less severe deformities are related to an incomplete anomaly. The contracture was corrected by dividing the superficialis tendon. The tonus of the superficialis muscle was normal and yet the tendon transfer was unsuccessful. This failure could be due to our operative technique. The tendon was sutured to the lumbrical tendon rather than to the extensor expansion. The failure could also be due to insufficient or incorrect splinting or to a superficialis tendon that did not function independently and therefore was useless as a transfer. The failure of the transfer into the central slip at the second operation suggests that the tendon did not have a normal muscle proximally. The improvement gained in extension by transferring superficialis IV further supports the view that superficialis V was abnormal. Because of the failure of the first two operations superficialis IV was transferred under considerable tension and this has resulted in limitation of flexion. This girl had no family history or other stigmata of Dupuytren's disease. Histologically the tissue was compatible with Dupuytren's disease, both on light and electron microscopy. The rapid appearance and disappearance of the disease is unexplained, but merits further investigation because cords of thickened fascia have been noted in other patients with camptodactyly, especially those patients who have been reoperated on. Patient No. 12. 1. H., a 12-year-old girl, had 55° of contracture of the right small finger that had become apparent during the previous year (Fig. 4, A). She had 45° of contracture of the left small finger. Both deformities were almost correctable passively with any position of the wrist. She had full flexion of all digits. At operation there was no lumbrical tendon and all of the muscle fibers attach to the tendon sheath and capsule of the MP joint (Fig. 4,B). There was no palmar interosseous IV, which would normally insert into the radial side of the extensor expansion. Superficialis V was divided and withdrawn from the tendon sheath. Lumbrical IV was
sutured to it and the tendon was sutured to the radial side of the extensor expansion (Fig. 4, C). The attitude of the digit is shown in Fig. 4, D. The finger was splinted most of the time for 3 months and at night for another 3 months. She has maintained almost full extension and has regained full flexion (Fig. 4, E). Comment. This case represents the best result obtained using superficialis V as a tendon transfer. Presumably it was not adherent to the superficialis IV and therefore had independent action. The lumbrical muscle was sutured to the tendon transfer and this would seem to be better than discarding the muscle. Patient No. 15. H. W., a 16-year-old boy, is the only patient treated for ring as well as small finger contracture. He had noticed the deformity for some time, bilaterally, but was concerned because the fingers of the right hand were becoming more flexed. On examination he had clawing of the small, ring, and long fingers as shown in Fig. 5, A. The deformities were passively correctable. The deformity of the fingers of the left hand was minimal. At operation only the small and ring fingers were treated. Lumbrical III attached to the extensor expansion of the long finger. It was left intact. Lumbrical IV attached to the capsule of the MP joint. Superficialis IV was divided and withdrawn into the palm. The slips were sutured to adjacent sides of the extensor expansions of the ring and small fingers. Lumbrical IV was sutured to the tendon slip transferred to the small finger. Superficialis V was not disturbed. Postoperatively he was only splinted for 3 weeks. Within 3 months he gained full extension (Fig. 5, B). Comment. This patient did well with minimal splinting, probably because he had full passive extension preoperatively and superficialis IV was an appropriate tendon to transfer. An abnormal insertion of the lumbrical muscle was found in the ring as well as the small finger.
Suggested treatment We have not operated on patients with a flexion contracture of less than 30°. If the results of operation were
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McFarlane et al.
better, perhaps patients with lesser contractures would be candidates for operation. Preoperative splinting for 2 or 3 months has been of some value in reducing the contracture in those patients who did not have full passive correction of the deformity. We prefer a static splint, wom for varying periods during the day and all night, rather than the dynamic splint recommended by Langford. 3 An operative technique has evolved in treating these 21 patients and can be described in four steps: (1) the incision, (2) examination of the lumbrical and interosseous muscles, (3) correction of secondary contractures, and (4) the tendon transfer. The incision. Having tried various lateral and zigzag incisions we recommend a midline palmar longitudinal incision. Distally it should extend far enough to expose the PIP joint. Proximally it must extend at least to the proximal palmar crease so that the lumbrical muscle is exposed and the superficialis tendons of the small and ring fingers are in view proximal to the origin of the lumbrical muscle. This incision provides excellent exposure of the entire flexor tendon mechanism. The neurovascular bundles need only be exposed in the proximal palm, where they pass superficial to the flexor tendons. A shortage of palmar skin varies in camptodactyly but is always present to some degree. By using a longitudinal incision this shortage can be corrected at the time of wound closure by incorporating two Zplasties in the finger and one in the palm. Examination of the lumbrical and interosseous muscles. Through the midline incision the flexor mechanism is exposed including the lumbrical muscle. An insertion of the muscle into the superficialis tendon will be obvious but further dissection is needed to demonstrate the insertion of the muscle into the tendon sheath and capsule of the MP joint or to the extensor expansion of the adjacent finger. Having done so one can dissect on the side of the proximal phalanx until the margin of the extensor expansion is exposed. The tendon of palmar interosseous IV, if present, will be found in this area. The muscle belly of this muscle can be inspected by dissecting proximally, incising the more distal fibers of the transverse metacarpal ligament. As mentioned previously the precise insertion of palmar interosseous IV is difficult to interpret without complete division of the ligament, but it is usually obvious if a tendon exists or if the tendon passes to the ring rather than the little finger. We have not disturbed the insertion of either muscle if it passed to the ring finger, but the insertion of the lumbrical onto the side of the MP joint is removed. Correction of secondary contractures. We assume
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that longitudinal shortage of skin, superficialis tendon, and joint structures are secondary to the longstanding flexion deformity. The skin shortage is corrected as described above. Abnormalities of the superficialis tendon of the small finger are common and therefore seen in patients with camptodactyly. It is often difficult to know if the superficialis tendon is contributing to the contracture at the PIP joint so it is divided routinely just proximal to the vincula longa. The flexor tendon sheath must be reflected to expose the superficialis tendon. When the finger has been straightened this structure cannot be resutured, which indicates that the tendon sheath is foreshortened as well. Usually the palmar plate is not tight, but if it is the proximal part should be released. Surgical judgment dictates what procedure is performed on the capsular structures of the PIP joint. It is better to accept a few degrees of persistent contracture than risk limitation of flexion postoperatively due to excessive scarring about the joint. The tendon transfer. As recorded in Table I superficialis V was used as the tendon transfer except in patient 15, in whom superficialis IV was used. The former tendon is the logical one to use because it has been divided at its insertion as one step in correction of the flexion contracture. The results using this tendon have been disappointing and we believe this is because the tendon frequently attaches to superficialis IV and thus lacks independent action. Also, in some patients the tendon was not suitable for transfer because it was either absent or lacked a proximal muscle belly. The proximal tonus of superficialis V can be tested at operation by holding the other fingers in extension and pulling on superficialis V. Even this test may be unreliable in revealing if the tonus is normal or sufficient to permit the tendon to function as a tendon transfer. We have used superficialis IV in most recently treated patients. The tendon is removed from the ring finger through an oblique incision on the palmar surface centered on the middle crease. It is divided just proximal to the vincula long a and drawn into the palm incision. The tendon has been passed both deep and superficial to the transverse metacarpal ligament. It would seem appropriate to pass it deep to the ligament to retain it, but sometimes it is technically difficult to do so. It has been attached to the free margin ofthe extensor expansion. Often the expansion is very delicate and it may be that this attachment is inadequate. The tendon has been attached to the central slip in two patients without any apparent improvement in action. The tendon has been sutured under considerable tension, which to date has not caused a reversal of the deformity except in patient 3. Rather than discard the lumbrical muscle it
Vol. 8, No.5, Part I September 1983
should be sutured to the tendon transfer if this does not interfere with tendon excursion. The wound is closed as described above. The hand is immobilized in a dorsal splint with the wrist and MP joint in flexion and the PIP joint in as much extension as possible. The dressing and splint applied in the operating room are replaced by a moulded plastic splint within 1 to 4 weeks, depending on the age and cooperation of the patient. Splinting for varying periods during the day and all night is continued under the direction of the therapist for about 3 months.
Results of operation Patients 18 to 21 are included in this series in order to document their findings at operation. They were operated on too recently to be considered in results. Superficialis V was used as a tendon transfer in 11 patients, but only three were improved. Superficialis IV was used in three patients and at a second or third operation in three other patients. Of these six patients three were improved. Only four of 18 digits (three patients) had full passive extension at the PIP joint preoperatively, but all four obtained a good result. Twelve patients did not have any surgical procedure on the palmar plate of the PIP joint. Six of these patients obtained a good result. Five patients had a palmar plate release and none of them obtained a good result. Sixteen of 17 patients had full flexion preoperatively, but only eight recovered full flexion after operation. Most of these patients were treated near the end of the series when surgical intervention of the joint structures was minimized. These results suggest the features associated with a good result. Such a patient would have less than 50° of contracture at the PIP joint and this would be passively correctable. At operation superficialis V would be divided, but the palmar plate would not be incised even though there was a persistent contracture of 20°. Superficialis IV would be used as the tendon transfer.
Discussion As noted by Smith and Kaplan, I virtually every structure in the finger has been implicated as a cause of camptodactyly. These authors observed that wrist flexion in some patients permitted PIP joint extension so they felt that contracture of superficialis V contributed to the deformity. However, Millesi 5 feels that shortening of the palmar soft tissues is secondary to lack of equilibrium between flexor and extensor forces. He recommends that the extensor apparatus be reinforced by a tendon transfer to restore balance. Furthermore,
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Millesi considers camptodactyly to be a syndrome rather than a special entity and that there are many reasons for the disturbance in equilibrium. Flatt6 supports this view in stating, "Camptodactyly is a clinical sign, possibly part of a syndrome, but is never a disease in its own right. " Courtemanche 7 described the insertion of the lumbrical muscle into the superficialis tendon in two patients (three hands). Millesi has observed this abnormal insertion also and credits Wilhelm with describing it previously.5 However, none of these authors believed that this abnormal lumbrical insertion was the only cause of camptodactyly. We observed this type of lumbrical insertion in only three of 21 patients, but found other types of anomalous insertion in the remaining eighteen patients. It is easy to miss the abnormal insertion of the lumbrical into the capsule of the MP joint. In fact, the muscle fibers must be dissected off the capsule before it becomes apparent that the muscle does in fact attach at that level and does not have a tendon of insertion into the extensor expansion. This seems a reasonable explanation of why others have not noticed an abnormal lumbrical insertion more often. Anatomical variations of the origin and insertion of the lumbrical muscles are common. 8-10 Of significance to this study of camptodactyly, anomalies of insertion are rare in the index finger but increase in frequency toward the small finger. Mehta and Gardiner lo found that lumbrical I inserted only into the extensor expansion of the index finger in 95% of cadaver hands, whereas a normal insertion of lumbrical II was noted in 90%, of lumbrical III in 48%, and of lumbrical IV in 17%. The most common anomaly was a split insertion, either into bone and tendon of the same digit or into the extensor expansions of adjacent digits. A misplaced insertion into the adjacent extensor expansion alone was noted less commonly and in one of the 75 hands the lumbrical inserted into the superficialis tendon. Results of these anatomical studies are consistent with the clinical presentation of camptodactyly that occurs on the ulnar side of the hand. According to Landsmeer, II the tendon of palmar interosseous IV has no bony insertion and therefore inserts into the extensor expansion with lumbrical IV. Therefore, the two muscles in question in this study have a similar insertion. We have observed varying degrees of abnormality of this conjoined insertion, from neither tendon inserting into the extensor expansion to varying contributions from both tendons. This has been most obvious with the tendon of the lumbrical muscle, which is usually absent but may be present in part. It is difficult to examine the tendon and muscle belly of
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v
TIl
III
IT
Fig. 6. Schematic drawings of the insertions of the lumbrical and interosseous tendons (after Landsmeerl l ). In comparing the small and ring fingers with the long and index fingers the lumbrical insertions are similar, but the interossei insert quite differently.
palmar interosseous IV without dividing the transverse metacarpal ligament and performing more dissection than is warranted, so it is possible that we have missed more subtle anomalies of insertion of the interosseous tendon. It may be that the severity of the deformity is related to the completeness of the anomaly. Also, it may be that the appearance of the deformity, at birth or adolescence, is related to the degree of completeness of the anomaly. There are reasonable objections to attributing the deformity of camptodactyly solely to the absence of lumbrical action. There are other intrinsic muscles of the small finger that extend the PIP joint, notably palmar interosseous IV and a slip of the abductor digiti minimi. Anomalies of palmar interosseous IV have been noted, but not consistently. In median palsy lumbrical I and II are paralyzed but clawing does not occur. As illustrated in Fig. 6, the normal anatomy of the lumbrical muscles is similar in each finger, but not so for the interossei. Perhaps the interossei of the index and long fingers are capable of preventing clawing in the absence of lumbrical action, whereas those of the ring and small fingers are not. Landsmeerl l believes that the lumbrical is a counter clawing muscle "par excellance." He sites the biomechanical and electromyographic evidence of Backhouse and Catton and Long and Brown that interphalangeal extension and lumbrical activity are interrelated in all positions of the MP joint. 12, 13 As noted by Valentin,14 the lumbrical tendon does not contribute to the extensor hood and therefore has greater functional autonomy than the interossei and can extend the interphalangeal joints in any position of the MP joint. It may be that some fibers of
the interossei to the index and long fingers possess this autonomy in order to prevent clawing in median palsy. There is an inherent tendency for the joints of the small finger to flex. In the position of function the small finger joints are flexed more than the other digits. In ulnar palsy the small finger is always more clawed than the ring finger. Scar contractures from lacerations and bums are more severe in this finger and it is much more difficult to maintain correction of Dupuytren's contracture of the small finger compared to other digits. Therefore, it is reasonable to postulate that some loss of extensor tonus at the PIP joint, which would occur with absent lumbrical action, could produce a flexion deformity as seen in camptodactyly. The deformity of camptodactyly is a claw deformity with hyperextension at the MP joint and flexion at the PIP joint. We have consistently observed that the insertion of the lumbrical muscle is abnormal. It seems reasonable, therefore, to state that the cause of camptodactyly is the absence of normal intrinsic action due to the anomalous insertion of the lumbrical muscle and perhaps the palmar interosseous as well. Therefore, we must disagree with Millesi and Flatt, who believe that camptodactyly is the result of many causes. The abnormal insertion of the lumbrical varies from an attachment to the capsule of the MP joint, or to the superficialis tendon, or the extensor expansion of the adjacent finger, and likely other attachments will be described. One might suggest that camptodactyly represents a syndrome of the wandering lumbrical. There is one patient in this series who had two involved fingers. In both of these fingers the insertion of the lumbrical was abnormal (patient 15, H. W.). It is
Vol. 8, No.5, Part I September 1983
reported that all fingers can be involved and that the deformity decreases toward the radial side of the hand. 6 Smith and Kaplan! described a patient similar to ours in whom the small, ring, and long fingers were involved. In our patient the clawing of the long finger disappeared after correction of the small and ring fingers. There is no report concerning treatment of camptodactyly of the index finger and what abnormality was found at operation. One wonders if the index finger is ever involved. A definition of camptodactyly. On the basis of our observations at operation on 21 consecutive patients we suggest that camptodactyly is a congenital deformity due to the anomalous insertion of the lumbrical muscle. It is always seen in the small finger, and occasionally also in the ring and long fingers. The deformity consists of hyperextension at the MP joint and flexion at the PIP joint. The distal interphalangeal joint is not affected. The deformity can be apparent at birth or at any time to puberty, but is usually apparent before 10 years of age. The deformity can be mild or severe and may be progressive even into adulthood. Correction of PIP joint contracture is easy, but it is difficult to maintain extension. Millesi 5 stressed the need to correct the imbalance between flexor and extensor forces by a tendon transfer. We are convinced that the deformity will recur if an intrinsic tendon transfer is not performed. Lankford3 refers to camptodactyly as an intrinsic weakness that requires a tendon transfer to overcome the weakness. The obvious tendon to transfer is superficialis V, but our results have been unpredictable and unsatisfactory with this transfer. It is well known that superficialis V is commonly abnormal in size and attachments and may be absent. In 50 cadaver dissections, Smith and Kaplan! found that 19 tendons arose from superficialis IV. Baker et al.!5 reported that 34% of normal hands have a defective superficialis V. Gaul stated, "don't assume that there is a working flexor superficialis just because you see the tendon structures within the sheath area.' '* This is certainly true in patients with camptodactyly. Within the flexor tendon sheath the superficialis may not only look normal, but may seem to have normal muscle tonus, and yet a tendon transfer fails. Superficialis IV would seem to offer a better solution to the problem. We have been reluctant to violate a normal digit, but believe now that superficialis IV is the best available tendon for transfer. Our results with the use of this tendon are not entirely satisfactory, but hopefully this is because of certain technical problems that need refinement. We believe that the transfer *Gaul JS: Personal communication.
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should be attached to the extensor expansion, rather than to the flexor tendon sheath or bone of the proximal phalanx, because the extrinsic extensor has been stretched by prolonged flexion at the PIP joint and needs augmentation. It is possible that superficialis IV, if sutured under too much tension, could overcorrect the deformity of camptodactyly and produce a swanneck deformity. This has not occurred in seven transfers performed to date, although one patient (No.3) developed this deformity when a superficialis V transfer was shortened at a second operation. All of the involved digits were x-rayed and in some there seemed to be some palmar angulation of the condyle of the proximal phalanx as well as pitting of the palmar cortex as described by Smith and Kaplan.! The appearance on the x-ray film had no bearing on the result; in fact, a patient in whom one of our best results was obtained had these x-ray findings. X-ray films of several older patients who had not been operated on and who had had the deformity for many years were normal. For these reasons we do not recommend that treatment be influenced by the radiological appearance of the PIP joint. Conclusion The deformity of camptodactyly is hyperextension at the MP joint and flexion at the PIP joint. An anomalous insertion of the lumbrical muscle was found in 21 consecutive patients operated on for camptodactyly. In five of the last 10 patients in this series an anomaly of the fourth palmar interosseous muscle was seen. We feel that this is sufficient evidence to state that camptodactyly is due to the loss of normal intrinsic muscle action. The essential part of treatment is to restore intrinsic extension by means of a tendon transfer. Addendum The data in this paper were presented to the members of the German Speaking Hand Society in March 1983. In the discussion that followed, Dr. A. Wilhelm said that he had published similar information on camptodactyly in 1968: Wilhelm A, Kleinschmidt W: Neue atiologische und therapeutische Gesichtspunkte bei der Kamptodaktylie und Tendovaginitis stenosans. Chir Plast Reconstr 5:62, 1968. The authors described the anomalous insertion of the lumbrical muscle and attributed the claw deformity of camptodactyly to the absence of normal lumbrical insertion and action. They considered the contractures of the palmar soft tissues to be the result rather than the cause of camptodactyly. Furthermore, they recommended superficialis tendon transfer although the number of patients operated upon
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and the results of treatment were not mentioned. The results of our investigation of camptodactyly compliments this earlier report. These two studies support the concept that camptodactyly is an entity caused by anomalous lumbrical insertion.
REFERENCES I. Smith RJ, Kaplan EB: Camptodactyly and Similar Atraumatic Flexion Deformities of the Proximal Interphalangeal Joints of the Fingers. J Bone Joint Surg [ Am] 50: 1187, 1968 2. Engber WD, Flatt AE: Camptodactyly: An analysis of sixty-six patients and twenty-four operations. J HAND SURG 2:216, 1977 3. Lankford LL: In Jones KG, Marmor L, Lankford LL, editors: An overview on new procedures in surgery of the hand. Clin Orthop 99:158, 1974 4. Curtis RM: Capsulectomy of the interphalangeal joints of the fingers. J Bone Joint Surg [Am] 36:1219, 1954 5. Millesi H: Camptodactyly. In Littler JW, Cramer LM, Smith JW, editors: Symposium on reconstructive hand surgery. St. Louis, 1974, The CV Mosby Co, pp 175-77 6. Flatt AE: The care of congenital hand anomalies. St. Louis, 1977, The CV Mosby Co, pp 147-54
7. Courtemanche AD: Camptodactyly: Etiology and management. Plast Reconstr Surg 44:451, 1969 8. Eyler DL, Markee JE: The anatomy and function of the intrinsic musculature of the fingers. J Bone Joint Surg [Am] 36A:1, 1954 9. Basu SS, Hazary S: Variations of the lumbrical muscles of the hand. Anat Rec 136:501, 1960 10. Mehta HJ, Gardner WU: A study of lumbrical muscles in the human hand. Am J Anat 109:227, 1961 II. Landsmeer JMF: Atlas of anatomy of the hand. New York, 1976, Churchill Livingstone, pp 294-332 12. Backhouse KM, Catton WT: An experimental study of the functions of the lumbrical muscles in the human hand. J Anat 88:133,1954 13. Long C, Brown ME: Electromyographic kinesiology of the hand: muscles moving the long finger. J Bone Joint Surg [Am] 46:1683, 1964 14. Valentin P: In Tubiana R, editor: The hand. Philadelphia, 1981, WB Saunders Company, vol I, pp 244-53 15. Baker DS, Gaul JS, Williams VK, Graves M: The little finger superficialis-a clinical investigation of its anatomical shortcomings. J HAND SURG 6:374, 1981
. Hands on Stamps Hungary-Issue of 1965. This stamp was issued to commemorate The International Year of Collaboration, 1965, and shows two hands expressing the sincere collaboration and friendship that must be respected among people. Submitted by Juraj Strmen, M.D. Fucikova 362/6, 01901 /lava Czechoslovakia
117. 118.
119.
120.
121.
Replantation and revascularization surgery in children. Hand 12: 12-24, 1980 Leung PC, Kok LC: Transplantation of the second toe to the hand. J Bone Joint Surg [Am] 62:990-6, 1980 Moberg E: Objective methods for determining sensibility in the hand. J Bone Joint Surg [Br] 40:454-66, 1958 Jabaley ME, Bums JE, Orcutt BS, Bryant WM: Comparison of histologic and functional recovery after peripheral nerve repair. J HAND SURG I: 119-30, 1976 Edshage S: Experience with clinical methods of testing sensation after peripheral nerve surgery. In Jewett DL, McCarroll HR, editors: Nerve repair and regeneration. Clinical and experimental basis. St. Louis, 1980, The C V Mosby Co, pp 244-9 Orner GE Jr: Sensation and sensibility in the upper extremity. Clin Orthop 104: 30-6, 1974
Sensibility and function with microvascular free tissue transfer
122. Orner EG Jr: Evaluation and reconstruction of the forearm and hand after acute peripheral nerve injuries. J Bone Joint Surg [ Am] 50: 1454-78, 1968 123. Craig JC: Pictorial and abstract cutaneous displays. In Geldard FA, editor: Conference on vibrotactile communication. Austin, Texas, 1974, Psychonomic Society, pp 78-83 124. Dyck PJ: Quantitation of cutaneous sensation in man. In Dyck PF, Thomas PK, Lambert EH, editors: Peripheral neuropathy. Philadelphia, 1975, W B Saunders Co, pp 465-79 125. Dellon AL: The moving two-point discrimination test: clinical evaluation of the quickly adapting fiber Ireceptor system. J HAND SURG 3:474-81, 1978
Anomalies of the intrinsic muscles in camptodactyly Our observations support the view of Millesi that camptodactyly is due to an imbalance between the flexor and extensor forces acting upon the proximal interphalangeal joint. In 21 consecutive operations the insertion of the lumbrical muscle was abnormal. The muscle inserted into either the superficialis tendon (in three cases), the capsule of the metacarpophalangeal joint (in 15), or the extensor expansion of the adjacent finger (in four). The fourth palmar interosseous muscle was examined in the last 10 patients and was abnormal in five. It was absent in two patients, small in one, and inserted into the extensor expansion of the ring finger in two patients. Therefore, it is suggested that camptodactyly is an intrinsic minus deformity. It follows that treatment should consist of soft tissue release, as necessary, to correct the flexion deformity, followed by a tendon transfer to restore intrinsic action and maintain correction of the deformity. (J HAND SURG 8:531.44, 1983.)
Robert M. McFarlane, M.D., G. Ian Curry, M.B., and H. Brian Evans, M.D.,
London, Ontario, Canada
Camptodactyly is a common defonnity of the small finger. An individual with a slight flexion contracture is not likely to seek medical advice but a contracture of 30° or more at the proximal interphalan· geal (PIP) joint will cause sufficient concern, if not a functional disability, for that person to inquire about From the Department of Surgery, Division of Plastic Surgery of Victoria Hospital, and the Faculty of Medicine of the University of Western Ontario. Received for publication Feb. 10, 1982; accepted in revised form Sept. 21, 1982. Reprint requests: Robert M. McFarlane, M.D., Dept. of Surgery, Victoria Hospital, 391 South St., London, Ontario, N6A 405, Canada.
treatment. The results of operation for camptodactyly have been unsatisfactory so that most surgeons are reo luctant to attempt correction of the defonnity. 1, 2 Patients with a mild contracture are usually advised to accept the defonnity. For more severe contractures, a variety of operations have been advised on the assumption that camptodactyly results from a variety of causes. Clinical series In January 1978, while operating on a patient with camptodactyly, we noticed for the first time the insertion of the lumbrical muscle of the small finger (lumbrical IV) into the superficialis tendon of the same THE JOURNAL OF HAND SURGERY
531
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Table I. Twenty-one consecutive patients with an anomaly of the lumbrical muscle Patient No.
Age (years)
Sex
Finger
Preop PIP ROM
2
Jan. 78 Aug. 78 Feb. 78
14 IS 16
M M F
LV LV RV
501110 75/95 551105
3
Feb. 78
4 5
II 12
Apr. 78 June 78 Mar. 79 June 81 July 78 June 79 Aug. 81 June 79 Sept. 79 Oct. 79 Dec. 79 Nov. 81 Jan. 80 Jan. 80
13 15 44 16 17 19 14 IS 17 16 10 6 13 IS 9 12
M M F F F F F F F M F F F F F F
RV RV LV RV RV RV RV RV RV RV LV LV LV LV RV RV
301100 70/95 701100 301105 501105 60/105 451105 60/90 65/95 701100 30/95 601100 551105 60/95 401100 551100
13
Apr. 80
12
F
RV
35/95
14
June 80
21
F
LV
651110
IS
Mar. 81
16
M
16 17 18
May 81 June 81 May 82
I 35 13
F F F
RV RIV RV LV RV
351105 30/105 501100 501105 651105
19
July 82
14
F
LV
75/95
20
July 82
13
F
LV
401100
21
Aug. 82
3
M
RV
55/100
6
7 8 9 10
Treated
Lumbrical insertion
Superf. V. Capsule MP Capsule MP Capsule MP Capsule MP
Capsule MP
Extensor IV Superf. V Capsule MP Capsule MP Capsule MP Capsule MP No palmar interos. Capsule MP No palmar interos. Capsule MP Small palmar interos. Capsule MP Extensor III Extensor IV Capsule MP Superf. V Capsule MP Palmar interos. to extensor IV Capsule MP Palmar interos. to extensor IV Extensor IV
PIP procedure
Manipulation Osteotomy prox. phal. None None Excise superf. slips Palmar plate release None Scar excision Palmar plate release None Scar excision Scar excision Palmar plate release None Palmar plate release None Palmar plate release None None
None
Palmar plate release
None Palmar plate release None* Palmar plate release None
None
None*
ROM = range of motion. *Superficialis V attached proximally to palmar aponeurosis without a muscle belly. Excised.
finger (superficialis V). Including this patient, we have found an abnormal insertion of lumbrical IV in a series of21 consecutive operations. Lumbrical IV was always present and always originated from the profundus tendon of the small finger, but the insertion varied. As listed in Table I, the most common anomaly was that the muscle fibers inserted into the flexor tendon sheath and capsule of the metacarpophalangeal (MP) joint without a tendon of insertion (15 fingers). In four fingers lumbrical IV had a tendinous insertion into the
extensor expansion of the adjacent finger. In three fingers lumbrical IV inserted into superficialis V. In patient 12 of this series we observed that palmar interosseous IV was absent. We had not examined this muscle before but have examined it at all subsequent operations. Palmar interosseous IV was absent in patient 13, was very small in patient 14, and it attached to the extensor expansion of the ring finger in patients 19 and 20. Therefore, an anomaly of palmar interosseous IV was noted in five of the last 10 patients in this series.
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Anomalies of intrinsic muscles in camptodactyly
Postop splinting (months)
ROM
To distal crease of palm
6 2 6
75/95 45/65 15/90
4.5 em 4.0 em 3.0 em
5 1 6 6 6 3 24 6 4 1 2 6 3 2 6
70/95 -10/60 34/45 501105 601105 15/40 60/90 65/95 40/85 55/95 25/95 75/80 60/95 25175 251100 201105
Superf. V to extensor
4
45/95
Superf. V to extensor
3
Superf. IV to extensor IV and V
2
Superf. IV to extensor Superf. IV to extensor Superf. V to extensor
1 6
Tendon transfer Superf. V to extensor Superf. V to extensor Superf. V to extensor Shorten transfer Superf. V to extensor Superf. V to extensor Superf. V to central slip Superf. IV to central slip Superf. V to extensor None Superf. IV to central slip None* None Superf. V to extensor Superf. V to extensor Superf. IV to extensor Lumbrical to extensor Superf. V to extensor
Postop PIP
em em em em em em em em em em em em em em em em
Comment Failure of transfer and loss of flexion Improved Decreased DIP flexion pre and postop Overeorreeted by transfer Failure of transfer Failure of transfer Failure of transfer Failure of transfer Improved Failure without tendon transfer Failure without tendon transfer Failure to transfer Failure of transfer Improved Improved Improved
0.0 em
Failure of transfer
0.0 em 0.0 em 0.0 em 2.5 em
Improved
Lost to followup 01105 01105 40/90 45/90
Failure of transfer Failure of transfer Superf. V used as transfer because normal muscle confirmed in fore-
arm
Superf. IV to extensor
Superf. V extensor
0.0 3.0 4.0 0.0 0.0 4.0 3.5 2.0 1.0 0.0 0.0 2.0 1.5 1.5 0.0 0.0
533
3
Superf. IV to extensor
Because the lumbrical muscle was always abnormal and the palmar interosseous muscle was occasionally abnormal we believe that there is reasonable evidence to suggest that the deformity of camptodactyly is due to the absence of intrinsic action. The appearance of the finger is in keeping with an intrinsic minus deformity because the MP joint is always in hyperextension in addition to the PIP joint being flexed (see Figs. 1, A, 3, C, 4, A, and 5, A). If the deformity is due to the absence of normal intrinsic action then the appropriate treatment would be to restore this action by tendon transfer. Furthermore, a tendon transfer should be per-
formed early, when the joint contracture is minimal and secondary changes in soft tissues and bone have not occurred. This paper documents the clinical features and the surgical findings in a series of 21 patients with camptodactyly. Also we will describe an operation that deals, not only with the primary problems of intrinsic muscle abnormality, but also with the secondary changes in skin, tendon, and joint structures. Some features of these patients are listed in Table I. The youngest patient was 1 year old and the oldest 44, but 13 of 21 were between 12 and 16 years old. It was
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Table II. Correction of deformity by superficialis release and transfer Patient No.
Preop passive extension at PIP
Correct contr. by release of super! V
Restore balance by transfer of super! V
No No Yes No No No No No No No No Yes No No Yes No No No No No No
No Yes Yes No Yes Yes No Not divided No Yes Not divided Yes Yes No Not divided Not divided No No No No No
No Yes Yes* No No No Excisedt Not transferred No No Not transferred:j: Yes No No Not transferred Not transferred Excisedt
2 3
4 5 6 7 8 9 10 II
12 13
14 15 16 17 18 19 20 21
Restore balance by transfer superj. IV
Result Failed Improved Improved Failed
Yes Yes Failed, no transfer Failed Failed, no transfer Yes
Yes No No
Good Good Failed Failed Good Failed Failed
Excised Excisedt
'Overcorrected by transfer. tNo proximal muscle belly. tLumbrical muscle transferred alone.
not possible to determine the age of onset of the contracture. The majority of patients were female (16 of 21). This may be because girls are more concerned about the appearance of their fingers. Most patients had bilateral deformities with one side more severe than the other, and this side was operated on. To date, no patient has requested operation on the opposite finger! The degrees of contracture ranged between 30° and 75°. No patient was offered an operation with a contracture of less than 30°. As listed in Table II, only three of 21 patients had full passive correction of the PIP joint contracture preoperatively. The conditions of each of these patients were improved by operation. We were unable to demonstrate correction of the deformity by flexon of the wrist (to relax the superficialis tendon) in any of these patients. Illustrative cases Patient No.1. C. T., a 14-year-old boy, had 50° of contracture at the PIP joint and full flexion preoperatively (Fig. I, A). X-ray films of the PIP joint were normal. The flexor tendons were exposed over the PIP joint and looked normal. With manipulation the joint was extended so that no surgical release of the soft tissues about the joint was performed. The flexor tendons were inspected proximal to the tendon sheath and muscle fibers were noted on superficialis V (Fig. 1, B). More proximal dissection revealed that these fibers were
lumbrical IV and originated in the normal way from the profundus tendon. Superficialis V was divided just proximal to the vincula longa and withdrawn. The lumbrical was removed. The tendon was passed deep to the transverse metacarpal ligament and sutured to the radial side of the extensor expansion. The appearance of the finger at the completion of the transfer is shown in Fig. 1, C. Postoperatively the boy did not cooperate with the splinting program. Within 2 months the contracture was 55° and by 6 months it was 75°. At a second operation an osteotomy of the proximal phalanx corrected the deformity to the extent shown in Fig. 1, D and E. Comment. This was the first patient in the series and the abnormality of the lumbrical muscle was noted only because it was so obvious. However, even this anomaly would have been missed if the incision had not extended well into the palm. The transfer of superficialis V to the extensor expansion failed either because the patient did not cooperate or because superficialis V did not have independent action and therefore was unsatisfactory as a tendon transfer. Patient No.3. J. S., a 13-year-old boy, had 30° of contracture at the PIP joint. At operation lumbrical IV was found attached to the flexor tendon sheath and the capsule of the MP joint, although a few rudimentary tendinous fibers were attached to the extensor expansion (Fig. 2, A). The muscle was resected. The tendon sheath was opened over the PIP joint. Because he had passive extension at the joint no soft tissue release was needed. Superficialis V was sectioned and withdrawn. It was passed deep to the transverse metacarpalligament and sutured to the radial side of the extensor expansion.
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Fig. 1. Patient No.1. A, The typical deformity of camptodactyly with hyperextension at the MP joint and flexion at the PIP joint. B, In the most proximal part of the wound lumbrical IV can be seen to insert into superficialis V just as the tendon enters the flexor tendon sheath (arrow). C, After transfer of superficialis V the MP joint hyperextension is gone and the PIP joint is more extended. D and E, The range of flexion and extension after an osteotomy of the proximal phalanx. Note that the MP joint hyperextension has recurred. Postoperatively extension at the PIP joint was maintained while the patient was wearing a splint, but it was lost when the splint was removed for varying periods during the day. One year after operation the deformity was 70°. At a second operation, the distal slips of superficialis V were found adherent within the tendon sheath. Upon their removal and lysis of the profundus tendon the PIP joint straightened. The superficialis tendon transfer was too lax and was adherent (Fig. 2, B and C). The tendon was lysed and
shortened by 2 cm. There was good proximal tonus of the tendon. Postoperatively, PIP joint extension was maintained, but he had difficulty regaining flexion and also developed a mallet finger deformity. The result 2 years later is shown in Fig. 2, D and E. Comment. This patient shows the usual anomaly of lumbrical IV. Almost all of the muscle fibers attached to structures around the MP joint. It is not unusual to see some muscle fibers extend to the radial side of the extensor expan-
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Fig. 2. Patient No.3. A, Anomalous insertion of lumbrical IV into the flexor tendon sheath and the capsule ofthe MP joint. Most of the muscle fibers have been released from their insertion, leaving a few on a rudimentary tendon that proceeded to the extensor expansion (arrow) . Band C, The superficialis transfer failed to extend the PIP joint, even though full passive extension was present as shown at the second operation . D and E, The result after shortening the transfer. He has full extension at the PIP joint, but lacks full finger flexion and has a mallet finger. sion, or to have a delicate tendon extend to the expansion, but when traction is applied to the body of the muscle there is no transmission to the expansion . This patient also illustrates the problem of balance in performing the tendon transfer. At the first operation the transfer was too loose whereas it was tightened excessively at the second operation . Patient No.5. 1. W ., a 16-year-old girl , had only 30° of contracture, but was concerned about the appearance of her finger. At operation, about one third of the muscle fibers were
found attached to the tendon sheath at the level of the MP joint, whereas the remaining fibers entered a small but normal looking tendon (Fig. 3, A) . The muscle was detached from the tendon sheath and sutured to the small lumbrical tendon . Upon division of superficialis V the PIP joint straightened. The tendon had normal tonus and was sutured to the lumbrical tendon (Fig. 3, B). In spite of splinting, the contracture recurred and within 3 months was 60°. At a second operation the cause of the contracture, as in the
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Fig. 3. Patient No . 5. A, Anomalous insertion of lumbrical IV into the flexor tendon sheath . The muscle belly is supported by a probe and the level of the MP joint is marked with black ink on the flexor tendon sheath. The free edge of the extensor expansion is held by forceps. About one third of the muscle inserted into the tendon sheath. The remainder inserted by way of a tendon into the extensor expansion . B, Superficialis V and some of the lumbrical muscle were sutured to the lumbrical tendon at its insertion into the extensor expansion. C and D, Appearance of the finger after two operations. There is slight MP joint hyperextension and 55° of PIP joint flexion. The patient had developed a nodule of Dupuytren's disease in the palm and tight fascia to the ring and long fingers that caused 15° of flexion contracture at the MP joint of both fingers. E and F, The range of flexion and extension 6 months after superficialis I V transfer. previous case, was adherence of the superficialis slips . Upon excision of these slips the joint straightened. The superficiaiis transfer was adherent to surrounding tissue. It was freed and rerouted to the dorsum of the finger where it was sutured to the central slip of the extensor expansion. Postoperatively
extension was maintained only as long as the finger was splinted continuously. Within 6 months the patient had 55° of flexion contracture (Fig. 3, C) . At this time she complained that she was unable to fully extend the ring and long fingers and had noted some lumps in her palm (Fig. 3, D). These
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Fig. 4. Patient No. 12. A, The typical appearance of camptodactyly. B, Lumbrical IV is held with the smooth retractor. The entire muscle inserts into the flexor tendon sheath. C, Lumbrical IV has been sutured to superficialis V, which is to be transferred to the extensor expansion. D, The position of the finger at the completion of the transfer. The MP joint is slightly flexed and the PIP joint extended. E, The final result showing full extension of the small finger. were typical of Dupuytren's disease. A third operation was performed. A nodule of Dupuytren's disease was removed. The lumbrical tendon and superficialis transfer were adherent to surrounding tissue and therefore removed. It was necessary to incise the palmar plate of the PIP joint to gain extension at the joint. Superficialis IV was transferred and sutured to the middle slip of the extensor tendon at the site where the superficialis V had been attached. Also, the extensor tendon was lysed because of adhesions. A Kirschner wire held the PIP
joint in extension for 3 weeks and then a splint was applied. It was removed for varying periods, on the advice of the therapist, in order to regain flexion and maintain extension. Three months after operation there was no evidence of Dupuytren's disease and she could fully extend the ring and long fingers. The range of movement at the PIP joint of the small finger was 25/35. At 6 months it was 15/40 with full passive extension, but she still was unable to fully flex the finger (Fig. 3, E and F).
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Fig. 5. Patient No. 15. A, Camptodactyly of the small, ring, and long fingers with the deformity decreasing in severity towards the radial side of the hand. B, After transfer of superficialis IV to the small and ring fingers he gained full extension, and also retained full flexion. Comment. The insertion of the lumbrical muscle was abnormal, but part of the muscle entered a normal tendon. It may be that the less severe deformities are related to an incomplete anomaly. The contracture was corrected by dividing the superficialis tendon. The tonus of the superficialis muscle was normal and yet the tendon transfer was unsuccessful. This failure could be due to our operative technique. The tendon was sutured to the lumbrical tendon rather than to the extensor expansion. The failure could also be due to insufficient or incorrect splinting or to a superficialis tendon that did not function independently and therefore was useless as a transfer. The failure of the transfer into the central slip at the second operation suggests that the tendon did not have a normal muscle proximally. The improvement gained in extension by transferring superficialis IV further supports the view that superficialis V was abnormal. Because of the failure of the first two operations superficialis IV was transferred under considerable tension and this has resulted in limitation of flexion. This girl had no family history or other stigmata of Dupuytren's disease. Histologically the tissue was compatible with Dupuytren's disease, both on light and electron microscopy. The rapid appearance and disappearance of the disease is unexplained, but merits further investigation because cords of thickened fascia have been noted in other patients with camptodactyly, especially those patients who have been reoperated on. Patient No. 12. 1. H., a 12-year-old girl, had 55° of contracture of the right small finger that had become apparent during the previous year (Fig. 4, A). She had 45° of contracture of the left small finger. Both deformities were almost correctable passively with any position of the wrist. She had full flexion of all digits. At operation there was no lumbrical tendon and all of the muscle fibers attach to the tendon sheath and capsule of the MP joint (Fig. 4,B). There was no palmar interosseous IV, which would normally insert into the radial side of the extensor expansion. Superficialis V was divided and withdrawn from the tendon sheath. Lumbrical IV was
sutured to it and the tendon was sutured to the radial side of the extensor expansion (Fig. 4, C). The attitude of the digit is shown in Fig. 4, D. The finger was splinted most of the time for 3 months and at night for another 3 months. She has maintained almost full extension and has regained full flexion (Fig. 4, E). Comment. This case represents the best result obtained using superficialis V as a tendon transfer. Presumably it was not adherent to the superficialis IV and therefore had independent action. The lumbrical muscle was sutured to the tendon transfer and this would seem to be better than discarding the muscle. Patient No. 15. H. W., a 16-year-old boy, is the only patient treated for ring as well as small finger contracture. He had noticed the deformity for some time, bilaterally, but was concerned because the fingers of the right hand were becoming more flexed. On examination he had clawing of the small, ring, and long fingers as shown in Fig. 5, A. The deformities were passively correctable. The deformity of the fingers of the left hand was minimal. At operation only the small and ring fingers were treated. Lumbrical III attached to the extensor expansion of the long finger. It was left intact. Lumbrical IV attached to the capsule of the MP joint. Superficialis IV was divided and withdrawn into the palm. The slips were sutured to adjacent sides of the extensor expansions of the ring and small fingers. Lumbrical IV was sutured to the tendon slip transferred to the small finger. Superficialis V was not disturbed. Postoperatively he was only splinted for 3 weeks. Within 3 months he gained full extension (Fig. 5, B). Comment. This patient did well with minimal splinting, probably because he had full passive extension preoperatively and superficialis IV was an appropriate tendon to transfer. An abnormal insertion of the lumbrical muscle was found in the ring as well as the small finger.
Suggested treatment We have not operated on patients with a flexion contracture of less than 30°. If the results of operation were
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better, perhaps patients with lesser contractures would be candidates for operation. Preoperative splinting for 2 or 3 months has been of some value in reducing the contracture in those patients who did not have full passive correction of the deformity. We prefer a static splint, wom for varying periods during the day and all night, rather than the dynamic splint recommended by Langford. 3 An operative technique has evolved in treating these 21 patients and can be described in four steps: (1) the incision, (2) examination of the lumbrical and interosseous muscles, (3) correction of secondary contractures, and (4) the tendon transfer. The incision. Having tried various lateral and zigzag incisions we recommend a midline palmar longitudinal incision. Distally it should extend far enough to expose the PIP joint. Proximally it must extend at least to the proximal palmar crease so that the lumbrical muscle is exposed and the superficialis tendons of the small and ring fingers are in view proximal to the origin of the lumbrical muscle. This incision provides excellent exposure of the entire flexor tendon mechanism. The neurovascular bundles need only be exposed in the proximal palm, where they pass superficial to the flexor tendons. A shortage of palmar skin varies in camptodactyly but is always present to some degree. By using a longitudinal incision this shortage can be corrected at the time of wound closure by incorporating two Zplasties in the finger and one in the palm. Examination of the lumbrical and interosseous muscles. Through the midline incision the flexor mechanism is exposed including the lumbrical muscle. An insertion of the muscle into the superficialis tendon will be obvious but further dissection is needed to demonstrate the insertion of the muscle into the tendon sheath and capsule of the MP joint or to the extensor expansion of the adjacent finger. Having done so one can dissect on the side of the proximal phalanx until the margin of the extensor expansion is exposed. The tendon of palmar interosseous IV, if present, will be found in this area. The muscle belly of this muscle can be inspected by dissecting proximally, incising the more distal fibers of the transverse metacarpal ligament. As mentioned previously the precise insertion of palmar interosseous IV is difficult to interpret without complete division of the ligament, but it is usually obvious if a tendon exists or if the tendon passes to the ring rather than the little finger. We have not disturbed the insertion of either muscle if it passed to the ring finger, but the insertion of the lumbrical onto the side of the MP joint is removed. Correction of secondary contractures. We assume
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that longitudinal shortage of skin, superficialis tendon, and joint structures are secondary to the longstanding flexion deformity. The skin shortage is corrected as described above. Abnormalities of the superficialis tendon of the small finger are common and therefore seen in patients with camptodactyly. It is often difficult to know if the superficialis tendon is contributing to the contracture at the PIP joint so it is divided routinely just proximal to the vincula longa. The flexor tendon sheath must be reflected to expose the superficialis tendon. When the finger has been straightened this structure cannot be resutured, which indicates that the tendon sheath is foreshortened as well. Usually the palmar plate is not tight, but if it is the proximal part should be released. Surgical judgment dictates what procedure is performed on the capsular structures of the PIP joint. It is better to accept a few degrees of persistent contracture than risk limitation of flexion postoperatively due to excessive scarring about the joint. The tendon transfer. As recorded in Table I superficialis V was used as the tendon transfer except in patient 15, in whom superficialis IV was used. The former tendon is the logical one to use because it has been divided at its insertion as one step in correction of the flexion contracture. The results using this tendon have been disappointing and we believe this is because the tendon frequently attaches to superficialis IV and thus lacks independent action. Also, in some patients the tendon was not suitable for transfer because it was either absent or lacked a proximal muscle belly. The proximal tonus of superficialis V can be tested at operation by holding the other fingers in extension and pulling on superficialis V. Even this test may be unreliable in revealing if the tonus is normal or sufficient to permit the tendon to function as a tendon transfer. We have used superficialis IV in most recently treated patients. The tendon is removed from the ring finger through an oblique incision on the palmar surface centered on the middle crease. It is divided just proximal to the vincula long a and drawn into the palm incision. The tendon has been passed both deep and superficial to the transverse metacarpal ligament. It would seem appropriate to pass it deep to the ligament to retain it, but sometimes it is technically difficult to do so. It has been attached to the free margin ofthe extensor expansion. Often the expansion is very delicate and it may be that this attachment is inadequate. The tendon has been attached to the central slip in two patients without any apparent improvement in action. The tendon has been sutured under considerable tension, which to date has not caused a reversal of the deformity except in patient 3. Rather than discard the lumbrical muscle it
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should be sutured to the tendon transfer if this does not interfere with tendon excursion. The wound is closed as described above. The hand is immobilized in a dorsal splint with the wrist and MP joint in flexion and the PIP joint in as much extension as possible. The dressing and splint applied in the operating room are replaced by a moulded plastic splint within 1 to 4 weeks, depending on the age and cooperation of the patient. Splinting for varying periods during the day and all night is continued under the direction of the therapist for about 3 months.
Results of operation Patients 18 to 21 are included in this series in order to document their findings at operation. They were operated on too recently to be considered in results. Superficialis V was used as a tendon transfer in 11 patients, but only three were improved. Superficialis IV was used in three patients and at a second or third operation in three other patients. Of these six patients three were improved. Only four of 18 digits (three patients) had full passive extension at the PIP joint preoperatively, but all four obtained a good result. Twelve patients did not have any surgical procedure on the palmar plate of the PIP joint. Six of these patients obtained a good result. Five patients had a palmar plate release and none of them obtained a good result. Sixteen of 17 patients had full flexion preoperatively, but only eight recovered full flexion after operation. Most of these patients were treated near the end of the series when surgical intervention of the joint structures was minimized. These results suggest the features associated with a good result. Such a patient would have less than 50° of contracture at the PIP joint and this would be passively correctable. At operation superficialis V would be divided, but the palmar plate would not be incised even though there was a persistent contracture of 20°. Superficialis IV would be used as the tendon transfer.
Discussion As noted by Smith and Kaplan, I virtually every structure in the finger has been implicated as a cause of camptodactyly. These authors observed that wrist flexion in some patients permitted PIP joint extension so they felt that contracture of superficialis V contributed to the deformity. However, Millesi 5 feels that shortening of the palmar soft tissues is secondary to lack of equilibrium between flexor and extensor forces. He recommends that the extensor apparatus be reinforced by a tendon transfer to restore balance. Furthermore,
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Millesi considers camptodactyly to be a syndrome rather than a special entity and that there are many reasons for the disturbance in equilibrium. Flatt6 supports this view in stating, "Camptodactyly is a clinical sign, possibly part of a syndrome, but is never a disease in its own right. " Courtemanche 7 described the insertion of the lumbrical muscle into the superficialis tendon in two patients (three hands). Millesi has observed this abnormal insertion also and credits Wilhelm with describing it previously.5 However, none of these authors believed that this abnormal lumbrical insertion was the only cause of camptodactyly. We observed this type of lumbrical insertion in only three of 21 patients, but found other types of anomalous insertion in the remaining eighteen patients. It is easy to miss the abnormal insertion of the lumbrical into the capsule of the MP joint. In fact, the muscle fibers must be dissected off the capsule before it becomes apparent that the muscle does in fact attach at that level and does not have a tendon of insertion into the extensor expansion. This seems a reasonable explanation of why others have not noticed an abnormal lumbrical insertion more often. Anatomical variations of the origin and insertion of the lumbrical muscles are common. 8-10 Of significance to this study of camptodactyly, anomalies of insertion are rare in the index finger but increase in frequency toward the small finger. Mehta and Gardiner lo found that lumbrical I inserted only into the extensor expansion of the index finger in 95% of cadaver hands, whereas a normal insertion of lumbrical II was noted in 90%, of lumbrical III in 48%, and of lumbrical IV in 17%. The most common anomaly was a split insertion, either into bone and tendon of the same digit or into the extensor expansions of adjacent digits. A misplaced insertion into the adjacent extensor expansion alone was noted less commonly and in one of the 75 hands the lumbrical inserted into the superficialis tendon. Results of these anatomical studies are consistent with the clinical presentation of camptodactyly that occurs on the ulnar side of the hand. According to Landsmeer, II the tendon of palmar interosseous IV has no bony insertion and therefore inserts into the extensor expansion with lumbrical IV. Therefore, the two muscles in question in this study have a similar insertion. We have observed varying degrees of abnormality of this conjoined insertion, from neither tendon inserting into the extensor expansion to varying contributions from both tendons. This has been most obvious with the tendon of the lumbrical muscle, which is usually absent but may be present in part. It is difficult to examine the tendon and muscle belly of
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v
TIl
III
IT
Fig. 6. Schematic drawings of the insertions of the lumbrical and interosseous tendons (after Landsmeerl l ). In comparing the small and ring fingers with the long and index fingers the lumbrical insertions are similar, but the interossei insert quite differently.
palmar interosseous IV without dividing the transverse metacarpal ligament and performing more dissection than is warranted, so it is possible that we have missed more subtle anomalies of insertion of the interosseous tendon. It may be that the severity of the deformity is related to the completeness of the anomaly. Also, it may be that the appearance of the deformity, at birth or adolescence, is related to the degree of completeness of the anomaly. There are reasonable objections to attributing the deformity of camptodactyly solely to the absence of lumbrical action. There are other intrinsic muscles of the small finger that extend the PIP joint, notably palmar interosseous IV and a slip of the abductor digiti minimi. Anomalies of palmar interosseous IV have been noted, but not consistently. In median palsy lumbrical I and II are paralyzed but clawing does not occur. As illustrated in Fig. 6, the normal anatomy of the lumbrical muscles is similar in each finger, but not so for the interossei. Perhaps the interossei of the index and long fingers are capable of preventing clawing in the absence of lumbrical action, whereas those of the ring and small fingers are not. Landsmeerl l believes that the lumbrical is a counter clawing muscle "par excellance." He sites the biomechanical and electromyographic evidence of Backhouse and Catton and Long and Brown that interphalangeal extension and lumbrical activity are interrelated in all positions of the MP joint. 12, 13 As noted by Valentin,14 the lumbrical tendon does not contribute to the extensor hood and therefore has greater functional autonomy than the interossei and can extend the interphalangeal joints in any position of the MP joint. It may be that some fibers of
the interossei to the index and long fingers possess this autonomy in order to prevent clawing in median palsy. There is an inherent tendency for the joints of the small finger to flex. In the position of function the small finger joints are flexed more than the other digits. In ulnar palsy the small finger is always more clawed than the ring finger. Scar contractures from lacerations and bums are more severe in this finger and it is much more difficult to maintain correction of Dupuytren's contracture of the small finger compared to other digits. Therefore, it is reasonable to postulate that some loss of extensor tonus at the PIP joint, which would occur with absent lumbrical action, could produce a flexion deformity as seen in camptodactyly. The deformity of camptodactyly is a claw deformity with hyperextension at the MP joint and flexion at the PIP joint. We have consistently observed that the insertion of the lumbrical muscle is abnormal. It seems reasonable, therefore, to state that the cause of camptodactyly is the absence of normal intrinsic action due to the anomalous insertion of the lumbrical muscle and perhaps the palmar interosseous as well. Therefore, we must disagree with Millesi and Flatt, who believe that camptodactyly is the result of many causes. The abnormal insertion of the lumbrical varies from an attachment to the capsule of the MP joint, or to the superficialis tendon, or the extensor expansion of the adjacent finger, and likely other attachments will be described. One might suggest that camptodactyly represents a syndrome of the wandering lumbrical. There is one patient in this series who had two involved fingers. In both of these fingers the insertion of the lumbrical was abnormal (patient 15, H. W.). It is
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reported that all fingers can be involved and that the deformity decreases toward the radial side of the hand. 6 Smith and Kaplan! described a patient similar to ours in whom the small, ring, and long fingers were involved. In our patient the clawing of the long finger disappeared after correction of the small and ring fingers. There is no report concerning treatment of camptodactyly of the index finger and what abnormality was found at operation. One wonders if the index finger is ever involved. A definition of camptodactyly. On the basis of our observations at operation on 21 consecutive patients we suggest that camptodactyly is a congenital deformity due to the anomalous insertion of the lumbrical muscle. It is always seen in the small finger, and occasionally also in the ring and long fingers. The deformity consists of hyperextension at the MP joint and flexion at the PIP joint. The distal interphalangeal joint is not affected. The deformity can be apparent at birth or at any time to puberty, but is usually apparent before 10 years of age. The deformity can be mild or severe and may be progressive even into adulthood. Correction of PIP joint contracture is easy, but it is difficult to maintain extension. Millesi 5 stressed the need to correct the imbalance between flexor and extensor forces by a tendon transfer. We are convinced that the deformity will recur if an intrinsic tendon transfer is not performed. Lankford3 refers to camptodactyly as an intrinsic weakness that requires a tendon transfer to overcome the weakness. The obvious tendon to transfer is superficialis V, but our results have been unpredictable and unsatisfactory with this transfer. It is well known that superficialis V is commonly abnormal in size and attachments and may be absent. In 50 cadaver dissections, Smith and Kaplan! found that 19 tendons arose from superficialis IV. Baker et al.!5 reported that 34% of normal hands have a defective superficialis V. Gaul stated, "don't assume that there is a working flexor superficialis just because you see the tendon structures within the sheath area.' '* This is certainly true in patients with camptodactyly. Within the flexor tendon sheath the superficialis may not only look normal, but may seem to have normal muscle tonus, and yet a tendon transfer fails. Superficialis IV would seem to offer a better solution to the problem. We have been reluctant to violate a normal digit, but believe now that superficialis IV is the best available tendon for transfer. Our results with the use of this tendon are not entirely satisfactory, but hopefully this is because of certain technical problems that need refinement. We believe that the transfer *Gaul JS: Personal communication.
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should be attached to the extensor expansion, rather than to the flexor tendon sheath or bone of the proximal phalanx, because the extrinsic extensor has been stretched by prolonged flexion at the PIP joint and needs augmentation. It is possible that superficialis IV, if sutured under too much tension, could overcorrect the deformity of camptodactyly and produce a swanneck deformity. This has not occurred in seven transfers performed to date, although one patient (No.3) developed this deformity when a superficialis V transfer was shortened at a second operation. All of the involved digits were x-rayed and in some there seemed to be some palmar angulation of the condyle of the proximal phalanx as well as pitting of the palmar cortex as described by Smith and Kaplan.! The appearance on the x-ray film had no bearing on the result; in fact, a patient in whom one of our best results was obtained had these x-ray findings. X-ray films of several older patients who had not been operated on and who had had the deformity for many years were normal. For these reasons we do not recommend that treatment be influenced by the radiological appearance of the PIP joint. Conclusion The deformity of camptodactyly is hyperextension at the MP joint and flexion at the PIP joint. An anomalous insertion of the lumbrical muscle was found in 21 consecutive patients operated on for camptodactyly. In five of the last 10 patients in this series an anomaly of the fourth palmar interosseous muscle was seen. We feel that this is sufficient evidence to state that camptodactyly is due to the loss of normal intrinsic muscle action. The essential part of treatment is to restore intrinsic extension by means of a tendon transfer. Addendum The data in this paper were presented to the members of the German Speaking Hand Society in March 1983. In the discussion that followed, Dr. A. Wilhelm said that he had published similar information on camptodactyly in 1968: Wilhelm A, Kleinschmidt W: Neue atiologische und therapeutische Gesichtspunkte bei der Kamptodaktylie und Tendovaginitis stenosans. Chir Plast Reconstr 5:62, 1968. The authors described the anomalous insertion of the lumbrical muscle and attributed the claw deformity of camptodactyly to the absence of normal lumbrical insertion and action. They considered the contractures of the palmar soft tissues to be the result rather than the cause of camptodactyly. Furthermore, they recommended superficialis tendon transfer although the number of patients operated upon
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and the results of treatment were not mentioned. The results of our investigation of camptodactyly compliments this earlier report. These two studies support the concept that camptodactyly is an entity caused by anomalous lumbrical insertion.
REFERENCES I. Smith RJ, Kaplan EB: Camptodactyly and Similar Atraumatic Flexion Deformities of the Proximal Interphalangeal Joints of the Fingers. J Bone Joint Surg [ Am] 50: 1187, 1968 2. Engber WD, Flatt AE: Camptodactyly: An analysis of sixty-six patients and twenty-four operations. J HAND SURG 2:216, 1977 3. Lankford LL: In Jones KG, Marmor L, Lankford LL, editors: An overview on new procedures in surgery of the hand. Clin Orthop 99:158, 1974 4. Curtis RM: Capsulectomy of the interphalangeal joints of the fingers. J Bone Joint Surg [Am] 36:1219, 1954 5. Millesi H: Camptodactyly. In Littler JW, Cramer LM, Smith JW, editors: Symposium on reconstructive hand surgery. St. Louis, 1974, The CV Mosby Co, pp 175-77 6. Flatt AE: The care of congenital hand anomalies. St. Louis, 1977, The CV Mosby Co, pp 147-54
7. Courtemanche AD: Camptodactyly: Etiology and management. Plast Reconstr Surg 44:451, 1969 8. Eyler DL, Markee JE: The anatomy and function of the intrinsic musculature of the fingers. J Bone Joint Surg [Am] 36A:1, 1954 9. Basu SS, Hazary S: Variations of the lumbrical muscles of the hand. Anat Rec 136:501, 1960 10. Mehta HJ, Gardner WU: A study of lumbrical muscles in the human hand. Am J Anat 109:227, 1961 II. Landsmeer JMF: Atlas of anatomy of the hand. New York, 1976, Churchill Livingstone, pp 294-332 12. Backhouse KM, Catton WT: An experimental study of the functions of the lumbrical muscles in the human hand. J Anat 88:133,1954 13. Long C, Brown ME: Electromyographic kinesiology of the hand: muscles moving the long finger. J Bone Joint Surg [Am] 46:1683, 1964 14. Valentin P: In Tubiana R, editor: The hand. Philadelphia, 1981, WB Saunders Company, vol I, pp 244-53 15. Baker DS, Gaul JS, Williams VK, Graves M: The little finger superficialis-a clinical investigation of its anatomical shortcomings. J HAND SURG 6:374, 1981
. Hands on Stamps Hungary-Issue of 1965. This stamp was issued to commemorate The International Year of Collaboration, 1965, and shows two hands expressing the sincere collaboration and friendship that must be respected among people. Submitted by Juraj Strmen, M.D. Fucikova 362/6, 01901 /lava Czechoslovakia