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Abductor digiti minimi opponensplasty in hypoplastic thumb
Abductor Digiti Minimi Opponensplasty in Hypoplastic Thumb T. OGINO, A. MINAMI and K. FUKUDA From Hokkaido University, Sapporo, Japan. Ten cases of hypoplastic thumbs were treated by abductor digiti minimi opponensplasty in order to restore opposition of the thumb and reform the wasted thenar eminence. In eight of these ten cases operations were combined with multiple Z-plasty or rotation flap to correct the narrowing of the first web space. Adductor plasty using extensor indicis proprius was performed in six cases to restore the stability of the metacarpophalangeal joint of the thumb and ligament reconstruction of the carpometacarpal joint in one hand. In all cases, the transferred abductor digiti minimi was strong enough to abduct the thumb and provide good functional and cosmetic results. We modified Littler’s procedure by transferring the origins of abductor digiti minimi muscle from the flexor carpi ulnaris to the palmaris longus tendon. Our modified method gave a better cosmetic appearance than that provided by Littler’s method.
Many surgical procedures are attempted for the treatment of hypoplastic thumb. Blauth (1967) classified the hypoplastic thumb into five grades. Grade four is floating thumb and grade five is aplasia of the thumb. For grades four and five hypoplastic thumb, pollicisation is the best choice of treatment. For grade two hypoplastic thumb, which has hypoplastic thenar muscles, opponensplasty is necessary to restore powerful grasp and fine pinch. Many types of opponensplasty were described and every procedure has strong points. Abductor digiti minimi opponensplasty is the only way to restore adequate opposition and thenar eminence simultaneously. Abductor digiti minimi opponensplasty was described by Huber (1921) for the treatment of median nerve injury. Littler (1963) suggested use of this transfer for patients with congenital absence of the thenar muscles. He transferred the abductor digiti minimi with continuity to the flexor carpi ulnaris tendon. Wissinger (1977) and Manske (1978), reported the results of this procedure for patients with congenital absence of the thenar muscles. They did not recommend complete detachment of the muscle from its osseous origin. Since 1976 we modified this procedure by transferring the origin of the abductor digiti minimi muscle from the flexor carpi ulnaris and pisiform to the palmaris longus tendon or transverse carpal ligament (Ogino, 1979). This paper presents the results of our modified procedure of abductor digiti minimi opponensplasty for thenar muscle aplasia. Material
From 1976 to 1984, abductor digiti minimi opponensplasties were performed on ten patients with thumb hypoplasia. There were four male and six female patients with four procedures on the left hand and six on the right hand. The opposite hand was normal in five patients, but there were manifestations of radial Received for pubhcarmn October, 1985. ToshihikoOgino, M.D., Deparlment of Orthopaedic Surgery. University, Kita-15, &hi-S, Kiraku, Sapporo, 064 Japan.
372
School of Medicine,
Hokkaido
dysplasia of the opposite hands in three patients and thumb polydactyly of the opposite hand in two patients. One patient had pollicisation on the other side. The age at the time of operation ranged from one year four months to thirty years and averaged seven years and seven months. The patients have. been Followed an average of 46.4 months after the operation, ranging from twelve months to eight years. One patient has been lost to follow up. The patients were divided into two groups on the basis of their deformity. In eight hands there was an absence of the abductor pollicis brevis and opponens pollicis muscles, adduction contracture of the thumb and laxity of the metacarpophalangeal joint of the thumb (Grade two according to Blauth’s classification). In one patient there was aplasia of the thenar muscle, tapering of the proximal end of the first metacarpal bone and laxity of the metacarpophalangeal and’carpometacarpal joints of the thumb (Grade three according to Blauth’s classification). As for combined operations, adductor plasty with extensor indicis proprius was performed in five hands, extensor plasty of the thumb with extensor indicis proprius in one hand and ligament reconstruction of the first carpometacarpal joint by using a free tendon graft i.n one hand. Skin-plasty of the first web was also performed in eight hands simultaneously. Z-plasty was used in two of these hands, a rotation flap from the extensor side of the index finger in five hands, and a rotation flap from the volar aspect of the thumb in one hand. Operative
Technique
Using a tourniquet for haemostasis, two skin incisions are made. The first originates from the ulnar border of the proximal phalanx of the little finger and curved radial volar ward proximal to the metacarpophalangeal joint. The incision extends to the radial border of the THE JOURNAL
OF HAND SURGERY
OPPONENSPLASTYIN HYPOPLASTIC THUMB
FCU Fig. 1
N. ulnaris A. ulnaris Opponensplasty with abductor digiti minimi: FCU: Flexor Carpi Ulnaris; PL: Palmaris Longus; A.Ulnaris: ulnar artery; N.Ulnaris: ulnar nerve.
hypothenar eminence to cross the wrist crease on the radial side of pisiform. Abductor digiti minimi is exposed by undermining the skin. The tendinous insertion to the extensor hood and to the base of the proximal phalanx of the little finger is detached. The origin of the abductor digiti minimi is also detached from the pisiform with one or two centimetres of tendon slip from the flexor carpi ulnaris. This tendon slip makes it easy to reattach the origin of abductor digiti minimi. We recommend complete detachment of the abductor digiti minimi muscle from its osseous origin and also prevention of the continuity to the flexor carpi ulnaris muscle. This is our modification of Littler’s method. The neurovascular pedicle is isolated and the abductor digiti minimi is lifted from its fascial compartment. A second semilunar incision is made over the dorsal radial aspect of the metacarpophalangeal joint of the thumb and the mobilized muscle is passed through a subcutaneous tunnel from the ulnar incision to the thumb incision. This tunnel should be made large enough through the superficial surface of the palmar VOL. 11-BNo. 3 OCTOBER 1986
P.L.
fascia that the muscle glides freely. The origin of the abductor digiti minimi is sutured to the palmaris longus tendon. If the palmaris longus tendon is absent, the origin is sutured to the transverse carpal ligament. In order to avoid tension in the neurovascular pedicle of the abductor digiti minimi, the ulnar nerve and artery should be released to some extent. As for the method of inserting the transferred tendon at the metacarpophalangeal joint, one of the transferred slips is sutured to the radial base of the proximal phalanx and the other to the extensor pollicis longus proximal to the metacarpophalangeal joint. When the opponensplasty is performed without adductor plasty, the thumb is held in the opposition position in a bulky dressing for one week. After removal of the dressing, the thumb is held in opposition by a plastic splint for an additional four weeks. When adductor plasty by using extensor indicis proprius is combined, the thumb is held in opposition in a bulky dressing and the wrist is held in neutral position by a plaster splint for three weeks. Then the fixation of the thumb into the opposition position by a plastic splint continues for an additional two weeks. 373
T. OGINO, A. MINAMI AND K. FUKUDA
Fig. 2
Preoperative (above) and postoperative (below) external appearance and preoperative X-rays (above right) in case 5. Normal opposition and thenar eminence were restored.
As Manske (1978) mentioned, it is difficult to evaluate post operative improvement of opposition in young children who have had reconstructive hand surgery for congenital defects. In this series the following criteria were evaluated: (1) the patient’s or parents’ opinion of the result; (2) the performance of daily activities; (3) the appearance of the hand; (4) the improvement of the pinch function; (5) the stability of the metacarpophalangeal joint. The relationship between the preoperative limitation of the interphalangeal joint movement and the postoperative improvement of the function and the stability of the metacarpophalangeal joint was also investigated. Results
In all patients, the transferred abductor digiti minimi muscles contracted usefully. All the patients or their parents were satisfied with the functional and the cosmetic improvement. No patients complained of disability in the performance of daily activities. In eight patients treated by our modified method, the 374
appearance of thenar eminence looked normal. In one patient, who was treated by Littler’s original procedure, the reconstructed thenar eminence shifted further to the ulnar side than normal.
The postoperative pinch function was compared with the preoperative status in Table 1. All patients had improvement of the pinch function after operation. Six of the nine patients had postoperative stability of the metacarpophalangeal joint and no deformity of the metacarpophalangeal joint of the thumb. The other three patients had radial deviation of the metacarpophalangeal joint of the thumb when pinching. For these three patients adductor plasty using extensor indicis proprius had been performed and they could adduct the thumb effectively and had dynamic stability of the metacarpophalangeal joint of the thumb. The two patients without preoperative limitation of the interphalangeal joint had good improvement of the pinch function and no instability or deformity. One of the six THE JOURNAL OF HAND SURGERY
OPPONENSPLASTY
IN HYPOPLASTIC
TABLE 1 Patient (No.) Sex Ooerated side Classification (Blauth) Anomalies of opposite extremity Age at operation (years) Additional operations Adductor plasty with EIP Extensor plasty with EIP First web plasty with Z plasty with rotation flap Length of follow up (years) Pinch function pre-operative posi-operative Radial deviation of the metacarpophalangeal joint of the thumb after operation
1 2 3 4 FFFFFMMMM RLRRRLRRL 2 2 2 2 TH N N TH 3 4.7 4.7 30
5
6
2 N 12
2 N 5
+ _
_
+ _
+ ~
_
+
+-+---++-+-+-++ 3 2 7 1
6
5
2
1
8
_
+ _
+ _
1
8
2 2 TP TP 8.3 2.6
9
3 N 1.3
NNPGFPGPN GEEEEEEEE
t+--+---
F: female, M: male, R: right, L: left, TH: thumb hypoplasia, TP: Thumb polydactyly, N: normal, t : The operation was performed, - : The operation was not performed. Criteria for pinch function: The patient can pinch between thumb and all fingers: Excellent (E), thumb and three fingers: Good (G), thumb and two fingers: Fair (F), thumb and one finger: Poor (P), thumb and no finger: No pinch function (N).
patients with preoperative limitation of the interphalangeal joint of the thumb had limitation of the pinch function after surgery and three of them had radial deviation when pinching. The improvement of the function of the thumb after surgery was better in the cases without preoperative limitation of the interphalangeal joint than in the cases with limitation of the joint. Case Reports Case 1. A left-handed female student was initially seen at the age of twelve years due to disturbance of thumb abduction. She had no treatment for her hand before visiting our hospital. Her mother noticed the thenar muscle hypoplasia when the patient was one-year-old. At eleven-years-old, she complained of difficulty playing the piano because she could not abduct her right thumb enough. Physical examination revealed that the thenar muscle was hypoplastic and the thumb had adduction contracture. She could not pinch between the thumb and ring and little fingers. Abductor digiti minimi opponensplasty was performed and the first web space was widened by multiple Z-plasty at the same time. Six years after the transfer of the abductor digiti minimi, there was no limitation of pinch function and the appearance of the hand was good. She had no difficulty playing the piano. Case 2. A sixteen-month-old right-handed boy presented with a Grade 3 thumb hypoplasia in his left hand. he had no pinch and no opposition function. Abductor digiti minimi transfer was performed on December 2nd 1976. Extensor indicis proprius was transferred to restore the extension of the thumb, and ligamentous reconstruction of the first carpometacarpal VOL. 11-B No. 3 OCTOBER
1986
THUMB
joint using palmaris longus free tendon graft was performed simultaneously on February 22nd 1979. In order to transfer the thumb proximally, skin plasty of the first web was performed by using the rotation flap from the radial volar aspect of the thumb on January 31st 1980. Five years after the last operation, the reconstructed thumb remained hypoplastic, he could, however, pinch between his thumb and all fingers. He had no disability in daily activity. Discussion
Slight thenar muscle hypoplasia, such as first grade hypoplasia according to Blauth’s classification, often causes no dysfunction of the thumb and it does not need to be treated surgically. The second grade thumb hypoplasia has no thenar muscle, no opposition and adduction contracture of the thumb and is often associated with instability of the metacarpophalangeal joint of the thumb. There are many kinds of opponensplasties which are different in available muscles or tendons. Littler (1963) mentioned the advantages of abductor digiti minimi opponensplasty as follows: 1. Intrinsic muscle replaces intrinsic muscle of similar excursion. 2. It does not need a pulley. 3. Abductor digiti minimi and abductor pollicis brevis seem to be synergistic and cortical reorientation adapted easily. 4. The wasted thenar eminence is reformed. The restoration of the thenar eminence is achieved only by abductor digiti minimi opponensplasty. This point is advantageous for the treatment of congenital thumb hypoplasia. As our results showed, in all cases the transferred abductor digiti minimi contracted usefully and improvement of the pinch function was also achieved. Muscle power restored by abductor digiti minimi opponensplasty is not less than after other procedures. The thenar eminence had a more normal appearance after surgery. In the patient who was treated by Littler’s procedure, that is, transferring the abductor digiti minimi with continuity to the flexor carpi ulnaris tendon, the reconstructed thenar eminence shifted further to the ulnar side than normal. The ulnar deviation of the thenar eminence was caused by the limitation of the distance in which abductor digiti minimi can be moved. In the cases which were treated by our own modified method, the thenar eminence looked more normal than in that treated by Littler’s procedure. Our modified method gave a better cosmetic appearance than that provided by Littler’s procedure. Our modified method gave a better cosmetic appearance than that provided by Littler’s method. We recommend complete detachment of the muscle from its osseous origin and resuturing to the palmaris longus tendon. However, for our modified procedure, good mobility of the neurovascular bundle to the abductor digiti minimi is necessary. The ulnar nerve, 375
T. OGINO, A. MINAMI AND K. FUKUDA
Fig. 3
Preooerative hypoplastic.
labovd and oostooerative (below) external However, the fun&ion is nearly’ normal.
ulnar artery and commitant vein were freed from Guyon’s canal and released proximally and distally. In our series, there was no circulatory disturbance and no neurological complications. Adduction contracture should be released at the time of opponensplasty in order to get a good functioning thumb (Flatt, 1977). For the mild adduction contracture, multiple Z-plasty was performed. For the moderate or severe adduction contracture, a rotation flap from the extensor aspect of the index finger was applied. For the Grade 3 hypoplastic thumb, the thumb was transferred in a proximal direction using a rotation flap from the volar aspect of the thumb. In all of our cases, adduction contracture was corrected satisfactorily by one of these methods. Another factor which influences the functional results is instability of the metacarpophalangeal joint of the thumb. The cause of this instability may be ligamentous instability and the absence of opponens pollicis muscle. 376
appearance
and
X-rays
in case
9. Keconstructed
tnumo
remamea
In four hands, there was instability of the metacarpophalangeal joint of the thumb preoperatively. For these four hands, adductor-plasty using extensor indicis proprius was performed at the time of opponensplasty. At the time of follow up, all hands had no instability of the metacarpophalangeal joint of the thumb when pinching, although three of these hands had the radial deviation of the metacarpophalangeal joint when pinching. When we performed opponensplasty and adductor plasty simultaneously, first the insertion of transferred abductor digiti minimi was sutured in the maximum palmar abduction position. Then the insertion of the transferred extensor indicis proprius was sutured for the adductor. We made the tension of the abductor digiti minimi tighter than that of the extensor indicis proprius. This is one of the reasons for the deviation of the metacarpophalangeal joint of the thumb when pinching. The other reason for the radial deviation of the metacarpophalangeal joint of the thumb is the adduction position THE JOURNAL OF HAND SURGERY
OPPONENSPLASTY
Fig. 4
Thenar eminence, treated by Littler’s original shifted more to the ulnar side than normal.
procedure,
of the first metacarpal bone caused by the deficiency of the opponens pollicis muscle. There was no harm in performing opponensplasty and adductor plasty simultaneously. The deviation of the metacarpophalangeal joint of the thumb when pinching does not influence the functional results. In order to prevent this deviation, imbrication of the ulnar capsule of the metacarpophalangeal joint, suturing the total insertion of the abdttctor digiti minimi to the first metacarpal bone or combined tendon transfer to pull the first metacarpal bone to the abduction position is recommended. On the occasion of the reconstruction of the Grade 2 hypoplastic thumb, the core of the reconstruction is opponensplasty. Adductor plasty and first web plasty should be combined according to their deformity and provided that there is no circulatory disturbance and no neurological complications. Acknowledgments It is the authors’ pleasant duty to express their sincere thanks to Professor Shigeo Matsuno, Department of
VOL. 11-B No. 3 OCTOBER 1986
IN HYPOPLASTIC
Fig. 5
THUMB
Radial thumb
deviation of the metacarpophalangeal after opponensplasty.
joint
of the
Orthopaedic Surgery, Hokkaido University, School of Medicine, for his suggestions and advice throughout this study.
References BLAUTH, W. (1967). Der hypoplastische Daumen. Archiv ftir orthoptidische and Unfall-Chtiurgie, 62: 225-246. FLATT, A. E. The Care of Congenital Hand Anomalies. St. Louis, The CV Mosby Company, (1977), 69. HUBER, E. (1921). Hilfsoperation bei Medianuslahmung. Deutsche Zeitschrift ftir Chirurgie, 162: 271-275. LITTLER, J. W. and COOLEY, S. G. E. (1963). Opposition of the Thumb and Its Restoration by Abductor Digiti Minimi Transfer. The Journal of Bone and Joint Surgery, 45A: 7: 1389-1396. MANSKE, P. R. and McCARROLL, H. R. (1978). Abductor digiti minimi opponensplasty in congenital radial dysplasia. The Journal of Hand Surgery, 3: 6: 552-559. OGINO, T. and ISHII, S. (1979). Opponensplasty by abductor digiti minimi. Application to hypoplastic thumb (Japanese). Rinsho Seikeigeka, 14: 867-873. WISSINGER, H. A. and SINGSEN, E. G. (1977). Abductor Digiti Quinti Opponensplasty. The Journal of Bone and Joint Surgery, 59A: 7: 895-898.
377
Many surgical procedures are attempted for the treatment of hypoplastic thumb. Blauth (1967) classified the hypoplastic thumb into five grades. Grade four is floating thumb and grade five is aplasia of the thumb. For grades four and five hypoplastic thumb, pollicisation is the best choice of treatment. For grade two hypoplastic thumb, which has hypoplastic thenar muscles, opponensplasty is necessary to restore powerful grasp and fine pinch. Many types of opponensplasty were described and every procedure has strong points. Abductor digiti minimi opponensplasty is the only way to restore adequate opposition and thenar eminence simultaneously. Abductor digiti minimi opponensplasty was described by Huber (1921) for the treatment of median nerve injury. Littler (1963) suggested use of this transfer for patients with congenital absence of the thenar muscles. He transferred the abductor digiti minimi with continuity to the flexor carpi ulnaris tendon. Wissinger (1977) and Manske (1978), reported the results of this procedure for patients with congenital absence of the thenar muscles. They did not recommend complete detachment of the muscle from its osseous origin. Since 1976 we modified this procedure by transferring the origin of the abductor digiti minimi muscle from the flexor carpi ulnaris and pisiform to the palmaris longus tendon or transverse carpal ligament (Ogino, 1979). This paper presents the results of our modified procedure of abductor digiti minimi opponensplasty for thenar muscle aplasia. Material
From 1976 to 1984, abductor digiti minimi opponensplasties were performed on ten patients with thumb hypoplasia. There were four male and six female patients with four procedures on the left hand and six on the right hand. The opposite hand was normal in five patients, but there were manifestations of radial Received for pubhcarmn October, 1985. ToshihikoOgino, M.D., Deparlment of Orthopaedic Surgery. University, Kita-15, &hi-S, Kiraku, Sapporo, 064 Japan.
372
School of Medicine,
Hokkaido
dysplasia of the opposite hands in three patients and thumb polydactyly of the opposite hand in two patients. One patient had pollicisation on the other side. The age at the time of operation ranged from one year four months to thirty years and averaged seven years and seven months. The patients have. been Followed an average of 46.4 months after the operation, ranging from twelve months to eight years. One patient has been lost to follow up. The patients were divided into two groups on the basis of their deformity. In eight hands there was an absence of the abductor pollicis brevis and opponens pollicis muscles, adduction contracture of the thumb and laxity of the metacarpophalangeal joint of the thumb (Grade two according to Blauth’s classification). In one patient there was aplasia of the thenar muscle, tapering of the proximal end of the first metacarpal bone and laxity of the metacarpophalangeal and’carpometacarpal joints of the thumb (Grade three according to Blauth’s classification). As for combined operations, adductor plasty with extensor indicis proprius was performed in five hands, extensor plasty of the thumb with extensor indicis proprius in one hand and ligament reconstruction of the first carpometacarpal joint by using a free tendon graft i.n one hand. Skin-plasty of the first web was also performed in eight hands simultaneously. Z-plasty was used in two of these hands, a rotation flap from the extensor side of the index finger in five hands, and a rotation flap from the volar aspect of the thumb in one hand. Operative
Technique
Using a tourniquet for haemostasis, two skin incisions are made. The first originates from the ulnar border of the proximal phalanx of the little finger and curved radial volar ward proximal to the metacarpophalangeal joint. The incision extends to the radial border of the THE JOURNAL
OF HAND SURGERY
OPPONENSPLASTYIN HYPOPLASTIC THUMB
FCU Fig. 1
N. ulnaris A. ulnaris Opponensplasty with abductor digiti minimi: FCU: Flexor Carpi Ulnaris; PL: Palmaris Longus; A.Ulnaris: ulnar artery; N.Ulnaris: ulnar nerve.
hypothenar eminence to cross the wrist crease on the radial side of pisiform. Abductor digiti minimi is exposed by undermining the skin. The tendinous insertion to the extensor hood and to the base of the proximal phalanx of the little finger is detached. The origin of the abductor digiti minimi is also detached from the pisiform with one or two centimetres of tendon slip from the flexor carpi ulnaris. This tendon slip makes it easy to reattach the origin of abductor digiti minimi. We recommend complete detachment of the abductor digiti minimi muscle from its osseous origin and also prevention of the continuity to the flexor carpi ulnaris muscle. This is our modification of Littler’s method. The neurovascular pedicle is isolated and the abductor digiti minimi is lifted from its fascial compartment. A second semilunar incision is made over the dorsal radial aspect of the metacarpophalangeal joint of the thumb and the mobilized muscle is passed through a subcutaneous tunnel from the ulnar incision to the thumb incision. This tunnel should be made large enough through the superficial surface of the palmar VOL. 11-BNo. 3 OCTOBER 1986
P.L.
fascia that the muscle glides freely. The origin of the abductor digiti minimi is sutured to the palmaris longus tendon. If the palmaris longus tendon is absent, the origin is sutured to the transverse carpal ligament. In order to avoid tension in the neurovascular pedicle of the abductor digiti minimi, the ulnar nerve and artery should be released to some extent. As for the method of inserting the transferred tendon at the metacarpophalangeal joint, one of the transferred slips is sutured to the radial base of the proximal phalanx and the other to the extensor pollicis longus proximal to the metacarpophalangeal joint. When the opponensplasty is performed without adductor plasty, the thumb is held in the opposition position in a bulky dressing for one week. After removal of the dressing, the thumb is held in opposition by a plastic splint for an additional four weeks. When adductor plasty by using extensor indicis proprius is combined, the thumb is held in opposition in a bulky dressing and the wrist is held in neutral position by a plaster splint for three weeks. Then the fixation of the thumb into the opposition position by a plastic splint continues for an additional two weeks. 373
T. OGINO, A. MINAMI AND K. FUKUDA
Fig. 2
Preoperative (above) and postoperative (below) external appearance and preoperative X-rays (above right) in case 5. Normal opposition and thenar eminence were restored.
As Manske (1978) mentioned, it is difficult to evaluate post operative improvement of opposition in young children who have had reconstructive hand surgery for congenital defects. In this series the following criteria were evaluated: (1) the patient’s or parents’ opinion of the result; (2) the performance of daily activities; (3) the appearance of the hand; (4) the improvement of the pinch function; (5) the stability of the metacarpophalangeal joint. The relationship between the preoperative limitation of the interphalangeal joint movement and the postoperative improvement of the function and the stability of the metacarpophalangeal joint was also investigated. Results
In all patients, the transferred abductor digiti minimi muscles contracted usefully. All the patients or their parents were satisfied with the functional and the cosmetic improvement. No patients complained of disability in the performance of daily activities. In eight patients treated by our modified method, the 374
appearance of thenar eminence looked normal. In one patient, who was treated by Littler’s original procedure, the reconstructed thenar eminence shifted further to the ulnar side than normal.
The postoperative pinch function was compared with the preoperative status in Table 1. All patients had improvement of the pinch function after operation. Six of the nine patients had postoperative stability of the metacarpophalangeal joint and no deformity of the metacarpophalangeal joint of the thumb. The other three patients had radial deviation of the metacarpophalangeal joint of the thumb when pinching. For these three patients adductor plasty using extensor indicis proprius had been performed and they could adduct the thumb effectively and had dynamic stability of the metacarpophalangeal joint of the thumb. The two patients without preoperative limitation of the interphalangeal joint had good improvement of the pinch function and no instability or deformity. One of the six THE JOURNAL OF HAND SURGERY
OPPONENSPLASTY
IN HYPOPLASTIC
TABLE 1 Patient (No.) Sex Ooerated side Classification (Blauth) Anomalies of opposite extremity Age at operation (years) Additional operations Adductor plasty with EIP Extensor plasty with EIP First web plasty with Z plasty with rotation flap Length of follow up (years) Pinch function pre-operative posi-operative Radial deviation of the metacarpophalangeal joint of the thumb after operation
1 2 3 4 FFFFFMMMM RLRRRLRRL 2 2 2 2 TH N N TH 3 4.7 4.7 30
5
6
2 N 12
2 N 5
+ _
_
+ _
+ ~
_
+
+-+---++-+-+-++ 3 2 7 1
6
5
2
1
8
_
+ _
+ _
1
8
2 2 TP TP 8.3 2.6
9
3 N 1.3
NNPGFPGPN GEEEEEEEE
t+--+---
F: female, M: male, R: right, L: left, TH: thumb hypoplasia, TP: Thumb polydactyly, N: normal, t : The operation was performed, - : The operation was not performed. Criteria for pinch function: The patient can pinch between thumb and all fingers: Excellent (E), thumb and three fingers: Good (G), thumb and two fingers: Fair (F), thumb and one finger: Poor (P), thumb and no finger: No pinch function (N).
patients with preoperative limitation of the interphalangeal joint of the thumb had limitation of the pinch function after surgery and three of them had radial deviation when pinching. The improvement of the function of the thumb after surgery was better in the cases without preoperative limitation of the interphalangeal joint than in the cases with limitation of the joint. Case Reports Case 1. A left-handed female student was initially seen at the age of twelve years due to disturbance of thumb abduction. She had no treatment for her hand before visiting our hospital. Her mother noticed the thenar muscle hypoplasia when the patient was one-year-old. At eleven-years-old, she complained of difficulty playing the piano because she could not abduct her right thumb enough. Physical examination revealed that the thenar muscle was hypoplastic and the thumb had adduction contracture. She could not pinch between the thumb and ring and little fingers. Abductor digiti minimi opponensplasty was performed and the first web space was widened by multiple Z-plasty at the same time. Six years after the transfer of the abductor digiti minimi, there was no limitation of pinch function and the appearance of the hand was good. She had no difficulty playing the piano. Case 2. A sixteen-month-old right-handed boy presented with a Grade 3 thumb hypoplasia in his left hand. he had no pinch and no opposition function. Abductor digiti minimi transfer was performed on December 2nd 1976. Extensor indicis proprius was transferred to restore the extension of the thumb, and ligamentous reconstruction of the first carpometacarpal VOL. 11-B No. 3 OCTOBER
1986
THUMB
joint using palmaris longus free tendon graft was performed simultaneously on February 22nd 1979. In order to transfer the thumb proximally, skin plasty of the first web was performed by using the rotation flap from the radial volar aspect of the thumb on January 31st 1980. Five years after the last operation, the reconstructed thumb remained hypoplastic, he could, however, pinch between his thumb and all fingers. He had no disability in daily activity. Discussion
Slight thenar muscle hypoplasia, such as first grade hypoplasia according to Blauth’s classification, often causes no dysfunction of the thumb and it does not need to be treated surgically. The second grade thumb hypoplasia has no thenar muscle, no opposition and adduction contracture of the thumb and is often associated with instability of the metacarpophalangeal joint of the thumb. There are many kinds of opponensplasties which are different in available muscles or tendons. Littler (1963) mentioned the advantages of abductor digiti minimi opponensplasty as follows: 1. Intrinsic muscle replaces intrinsic muscle of similar excursion. 2. It does not need a pulley. 3. Abductor digiti minimi and abductor pollicis brevis seem to be synergistic and cortical reorientation adapted easily. 4. The wasted thenar eminence is reformed. The restoration of the thenar eminence is achieved only by abductor digiti minimi opponensplasty. This point is advantageous for the treatment of congenital thumb hypoplasia. As our results showed, in all cases the transferred abductor digiti minimi contracted usefully and improvement of the pinch function was also achieved. Muscle power restored by abductor digiti minimi opponensplasty is not less than after other procedures. The thenar eminence had a more normal appearance after surgery. In the patient who was treated by Littler’s procedure, that is, transferring the abductor digiti minimi with continuity to the flexor carpi ulnaris tendon, the reconstructed thenar eminence shifted further to the ulnar side than normal. The ulnar deviation of the thenar eminence was caused by the limitation of the distance in which abductor digiti minimi can be moved. In the cases which were treated by our own modified method, the thenar eminence looked more normal than in that treated by Littler’s procedure. Our modified method gave a better cosmetic appearance than that provided by Littler’s procedure. Our modified method gave a better cosmetic appearance than that provided by Littler’s method. We recommend complete detachment of the muscle from its osseous origin and resuturing to the palmaris longus tendon. However, for our modified procedure, good mobility of the neurovascular bundle to the abductor digiti minimi is necessary. The ulnar nerve, 375
T. OGINO, A. MINAMI AND K. FUKUDA
Fig. 3
Preooerative hypoplastic.
labovd and oostooerative (below) external However, the fun&ion is nearly’ normal.
ulnar artery and commitant vein were freed from Guyon’s canal and released proximally and distally. In our series, there was no circulatory disturbance and no neurological complications. Adduction contracture should be released at the time of opponensplasty in order to get a good functioning thumb (Flatt, 1977). For the mild adduction contracture, multiple Z-plasty was performed. For the moderate or severe adduction contracture, a rotation flap from the extensor aspect of the index finger was applied. For the Grade 3 hypoplastic thumb, the thumb was transferred in a proximal direction using a rotation flap from the volar aspect of the thumb. In all of our cases, adduction contracture was corrected satisfactorily by one of these methods. Another factor which influences the functional results is instability of the metacarpophalangeal joint of the thumb. The cause of this instability may be ligamentous instability and the absence of opponens pollicis muscle. 376
appearance
and
X-rays
in case
9. Keconstructed
tnumo
remamea
In four hands, there was instability of the metacarpophalangeal joint of the thumb preoperatively. For these four hands, adductor-plasty using extensor indicis proprius was performed at the time of opponensplasty. At the time of follow up, all hands had no instability of the metacarpophalangeal joint of the thumb when pinching, although three of these hands had the radial deviation of the metacarpophalangeal joint when pinching. When we performed opponensplasty and adductor plasty simultaneously, first the insertion of transferred abductor digiti minimi was sutured in the maximum palmar abduction position. Then the insertion of the transferred extensor indicis proprius was sutured for the adductor. We made the tension of the abductor digiti minimi tighter than that of the extensor indicis proprius. This is one of the reasons for the deviation of the metacarpophalangeal joint of the thumb when pinching. The other reason for the radial deviation of the metacarpophalangeal joint of the thumb is the adduction position THE JOURNAL OF HAND SURGERY
OPPONENSPLASTY
Fig. 4
Thenar eminence, treated by Littler’s original shifted more to the ulnar side than normal.
procedure,
of the first metacarpal bone caused by the deficiency of the opponens pollicis muscle. There was no harm in performing opponensplasty and adductor plasty simultaneously. The deviation of the metacarpophalangeal joint of the thumb when pinching does not influence the functional results. In order to prevent this deviation, imbrication of the ulnar capsule of the metacarpophalangeal joint, suturing the total insertion of the abdttctor digiti minimi to the first metacarpal bone or combined tendon transfer to pull the first metacarpal bone to the abduction position is recommended. On the occasion of the reconstruction of the Grade 2 hypoplastic thumb, the core of the reconstruction is opponensplasty. Adductor plasty and first web plasty should be combined according to their deformity and provided that there is no circulatory disturbance and no neurological complications. Acknowledgments It is the authors’ pleasant duty to express their sincere thanks to Professor Shigeo Matsuno, Department of
VOL. 11-B No. 3 OCTOBER 1986
IN HYPOPLASTIC
Fig. 5
THUMB
Radial thumb
deviation of the metacarpophalangeal after opponensplasty.
joint
of the
Orthopaedic Surgery, Hokkaido University, School of Medicine, for his suggestions and advice throughout this study.
References BLAUTH, W. (1967). Der hypoplastische Daumen. Archiv ftir orthoptidische and Unfall-Chtiurgie, 62: 225-246. FLATT, A. E. The Care of Congenital Hand Anomalies. St. Louis, The CV Mosby Company, (1977), 69. HUBER, E. (1921). Hilfsoperation bei Medianuslahmung. Deutsche Zeitschrift ftir Chirurgie, 162: 271-275. LITTLER, J. W. and COOLEY, S. G. E. (1963). Opposition of the Thumb and Its Restoration by Abductor Digiti Minimi Transfer. The Journal of Bone and Joint Surgery, 45A: 7: 1389-1396. MANSKE, P. R. and McCARROLL, H. R. (1978). Abductor digiti minimi opponensplasty in congenital radial dysplasia. The Journal of Hand Surgery, 3: 6: 552-559. OGINO, T. and ISHII, S. (1979). Opponensplasty by abductor digiti minimi. Application to hypoplastic thumb (Japanese). Rinsho Seikeigeka, 14: 867-873. WISSINGER, H. A. and SINGSEN, E. G. (1977). Abductor Digiti Quinti Opponensplasty. The Journal of Bone and Joint Surgery, 59A: 7: 895-898.
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