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Operative correction of posttraumatic and congenital swanneck deformity—A new technique
Operative Correction of Posttraumatic and Congenital Swanneck Deformity-A New Technique R. P. KARTHAUS and G. J. I. M. van der WERF From Orthopedic Department, De Wever Ziekenhuis, The Netherlands. Volar plate reconstruction by using a part of the slip of the superficialis tendon is a new technique in the treatment of posttraumatic and congenital swanneck deformity. This small series represents two patients with a posttraumatic swanneck deformity due to volar plate rupture and one patient with a congenital swanneck deformity in six fingers. The results of the operation with a two years follow-up show seven fingers with a normal flexion-extension range without hyperextension. Only one finger has an extension lag of five degrees. All fingers have a normal grip strength and normal fine movements without pain. There were no complications. Hyperextension of the proximal interphalangeal joint, except in the occasional individual voluntary able to display it, constitutes a serious disruption of digital function. The mechanism, which invariably leads to concomitant flexion of the fingertip, has been analyzed by Landsmeer (1958). This swanneck-like condition of the finger may lead to locking of the proximal interphalangeal joint in hyperextension. It may be caused by congenital laxity or untreated traumatic trupture of the volar plate and (in some cases) concomitant lesions of the collateral ligaments of the joint. The congenital swanneck-deformity gives rise to the locking phenomena after a few years of progressive laxity of the volar plate and the collateral ligaments and becomes worse with aging. Operative treatment is indicated in case of recurrent hyperextension of the proximal interphalangeal joint with locking, catching and discomfort. In the literature we found different operative techniques with wide exposure and/or alteration of the normal anatomy of the finger resulting in restriction of finger motion and abnormal loading of the joint. Our operative correction provides a simple technique resulting in a full range of motion of the finger without deformation. Patients and Technique In the period 1981-1982, three patients underwent an operative correction of their swanneck deformity in a total of eight fingers. It concerns two patients with a traumatic hyperextension deformity of the proximal interphalangeal joint in one finger and one patient with a congenital hyperextension deformity of the joints of six fingers. The follow-up is at least two years. Received for publication June, 1985. Head of the Orthopaedic Department, Dr. A. J. Tonino. R. P. Karthaus and G. J. I. M. van der Werf, Orthopedic Department, Henri Dunantstr. 5, 6419PC Heerlen, The Netherlands.
VOL.
11-B No.
2 JUNE
1986
De Wever
Ziekenhuis,
The first patient was a sixteen-year-old, right-handed housemaid. She fell on her outstretched hand, resulting in a hyperextension trauma of the proximal interphalangeal joint of the middle finger of her right hand. The finger had a swollen joint with painful function. The swelling in the joint diminished in a couple of weeks and a gradually progressive hyperextension developed. There was a hyperextension of more than twenty degrees with locking and pain in the proximal joint of her middle finger. Operative correction of this swanneck deformity as described later, was performed four months after trauma. At operation only a thin fragment of the volar plate was found. Reattachment was not possible. Six weeks after operation the middle finger had full function of both interphalangeal joints, without hyperextension or extension lag. At clinical examination twenty-six months after operation the middle finger had a complete, normal and painless range of motion, without hyperextension of the proximal joint. The hand had a normal grip strength and normal fine finger movements. The second patient was a twenty-four-year-old, righthanded operator in the chemical industry. Eight months before his first visit there was a sport trauma of the ring finger of his left hand. Afterwards hyperextension of more than twenty degrees developed in the proximal joint of this finger with a locking phenomenon and discomfort. The ring finger had a full flexion range without pain, with normal grip strength and normal fine finger movements. There was no collateral instability. At operation eight months after the initial trauma, a scarred volar plate was found. The scar tissue did not affect the flexion range. After volar plate reconstruction following our technique, the finger regained normal flexion/extension range within eight weeks. There was no pain, no hyperextension or loss of grip strength. The fine finger movements were normal. 239
R. P. KARTHAUS AND G. J. I. M. van der WERF
At follow-up, twenty-seven months after operation, clinical examination showed the same results. The third patient was a fifteen-year-old, right-handed schoolgirl. From her early childhood there was a hyperextension of the proximal interphalangeal joints of all fingers. Since ten months a progressive locking of the joints in hyperextension developed in the index, middle and ring fingers of both hands. Active flexion could not be initiated in this position. Trying to do so gave rise to pain and more hyperextension. The flexion range was normal. Grip strength and fine finger movements were unaffected. Following our technique, the index, middle and ring fingers of both hands were operated on. Three months later the function of all but one finger showed full extension, without hyperextension. The index finger of the right hand had a five degrees extension lag. Flexion of all fingers was normal. Grip strength and fine finger movements had been unchanged. At follow-up of twenty-five months the condition of the six fingers has not changed. Grip strength is perfect. Fine finger movements are normal. There is only a minimal scar visible at the ulnar aspect of the proximal joint of the operated fingers. All the three patients were very satisfied with the results of the operation. There were no complications. All patients returned to their previous work within six weeks after operation. Operative Technique
Through a curved ulnar skin incision over the proximal interphalangeal joint expose and define the ulnar superficialis tendon slip. Avoid damage to the ulnarvolar neuro-vascular bundle. Split the ulnar superficialis tendon in equal parts, about one centimetre proximal to its insertion. Dissect the most ulnar part proximally forming a distal based slip of three centimetre length. Expose the volar aspect of the proximal phalanx. Inspect the volar plate (remnants). If necessary excise abundant scar tissue. Next drill a two millimetre hole in the proximal phalanx in a volar-dorsal direction, a few millimetres proximal to the joint and its synovial extent. Carry the freed half of the superficialis slip with an absorbable suture fixed at the end to the proximal ~phalanx. Thread it through the hole in the phalanx. Anchor the tendon slip in the proximal phalanx tieing the suture over a button on the dorsum of the finger, keeping the joint in fifteen degrees of flexion (Figure 1). Close the wound with interrupted absorbable sutures. Splint the finger with the joint in fifteen degrees of flexion. 240
Fig. 1
Modified Curtis technique of correcting hyperextension and locking of the proximal interphalangeal joint of the finger.
After three weeks the splint is removed, the suture on the dorsum of the finger is cut off and active exercises are begun. If necessary a nightsplint can be worn for a few weeks. In six to eight weeks the extension restriction of fifteen degrees subsides by normal exercise, leaving a full range of motion without deformity of the proximal interphalangeal joint. Discussion
Swanneck deformity represents a troublesome pathology of the finger, which may be produced by multiple causes. It is clinically characterised by recurvation of the middle joint and a flexed position of the distal joint. Normally the proximal joint cannot exceed ten degrees of hyperextension (Weeks, 1973). In swanneck-deformity the middle joint recurvation secondarily produces the opposite deformation of the distal joint. This functional relationship between the .,r,srphalangeal joints is also manifested by the magnitude of the deformity, since the greater the recurvation of the middle joint, the greater the flexion of the distal joint. According to the cause, which initiates the deformity Zancolli (1979) has classified three fundamental types of swanneck deformities: the extrinsic, intrinsic and articular type. The initial factor of the extrinsic type concerns an overaction of the long extensor tendon due to pathological flexion positions of the wrist and/or metacarpophalangeal joints, or tendinous adhesions or muscular shortening and spasticity (extensor plus finger). The intrinsic type of swanneck deformity can be produced in all cases in which there is an imbalance of THE JOURNAL OF HAND SURGERY
CONGENITALSWANNECKDEFORMITY
extensor/flexor activity with relative overaction of the intrinsic muscles due to ischaemic retraction, spasticity, rheumatic disease etc. The third type, the articular type, is caused by failure of any of the principal stabilisers of the joint. This may allow the beginning of recurvation of the joint by abnormal traction of the digital extension forces. The rest of the stabilising structures begin to give in. So the recurvation progresses, while the distal joint is immediately placed in a flexed position, losing its capacity of active extension. The principal causes of the loss of stabilising structures of the joint are: 1. direct injury of the volar plate or 2. elongation of the volar plate by rheumatic disease, 3. lack of superficialis tendon due to trauma or surgery, 4. elongation or destruction of the oblique laminae of the lateral retinacular ligaments, which favours pathological dorso-medial migration of the lateral extensor tendons, 5. hypertrophic, retractile scar over the dorsum of the joint and 6. congenital joint laxity. Lastly a swanneck deformity is possible in case of a mallet finger, in which the normal relationship of flexor-extensor in the proximal joint is disturbed by an extensor tendon lesion at the distal joint (Bowers, 1978). Restoring the normal anatomical relationship between extensor and flexor mechanism is in fact the only way of management of the swanneck deformity. Actually in the direct traumatic injury of the volar plate and in congenital joint laxity the lesion concerns only one simple structure, without damage to the flexor or extensor apparatus, resulting in a swanneck deformity. The latter two are very accessible for operative treatment. In longstanding cases of traumatic volar plate rupture, reconstruction of the volar plate using the original tissue is often impossible by retraction of the rests of the volar plate and scar formation. Sometimes this hypertrophic scar tissue inhibits the normal flexion range. At reconstruction of the volar plate this scar tissue has to be excised. The use of half of the ulnar slip will not change the normal superficialis physiological loading of the proximal interphalangeal joint. There will be no imbalance of force generated by the superficialis tendon. The extensor apparatus will be unaffected. The absorbable “pull-out” suture does not counteract the normal action of the extensor hood. The freed slip acting as an extension-inhibitor will be relaxed when the proximal joint is flexed (Figure 2). So there will be no restriction of flexion by the rerouted part of the superficialis slip. This part of the slip is capable of withstanding (hyper)extension in the proximal joint.
Inhibiting the hyperextension, the freed slip of the superficialis runs in a slightly diagonal direction, but the resultant force acting on the proximal joint will produce only a minimal torsion on the joint in full extension. VOL. 11-BNo. 2 JUNE 1986
Fig. 2
In flexion of the proximal interphalangeal joint the freed and rerouted superficialis slip has been withdrawn in a proximal direction.
This is in contrast with the Curtis technique (Edmondson-Crenshaw, 1980), where the whole superficialis slip is used, which runs diagonally over the joint, possibly resulting in an asymmetric flexor force acting on the base of the middle phalanx, and generating torsional stress on the proximal interphalangeal joint in full extension. Furthermore the loss of the ulnar superficialis tendon slip may allow easier hyperextension in the joint (Kaplan, 1936) by loss of the hyperextension-inhibiting effect of this part of the superficialis tendon. Bate (1945) described an operative technique suturing the contracted volar ligament to the anterior part of the proximal phalanx and shortening the anterior portion of the lateral capsule. This procedure gives rise to an extension lag of twenty degrees or more. This result may be acceptable, but still there is a restriction of extension. Further it changes the normal structure of the lateral capsule into a pathological one. Portis (1954) stated that the reattachment of the volar plate may be sufficient in treatment of the traumatic volar plate rupture with swanneck deformity. If this is not possible, because little or no volar plate can be found to repair, some other technique has to be used as replacement of the destroyed volar plate. Bunnell (Boyes, 1970) described a tendon graft to replace the volar plate. Following this technique Adams (1959) operated three fingers in two patients. One finger regained a full range of motion. The other two had a restriction of extension of five and twenty-five degrees respectively. One finger had a slight limitation of flexion in the follow-up. In this “criss-cross” technique 241
R. P. KARTHAUS AND G. J. I. M. van der WERF
there is a need for an ulnar and radial exposure as well. In extension the volar synovium of the joint may be damaged, forming scar tissue, resulting in limitation of flexion and/or extension.
Kleinert and Kasdan (1965) reported four cases. They reattached a portion of the collateral ligament more proximally to prevent full extension of the proximal joint. In three patients there was a minor loss of extension of five, ten and twenty degrees respectively. They used a bilateral approach to the joint, altering a normal structured collateral ligament to a collateral ligament with an abnormal origin. The overall result of this operation may be acceptable to excellent, but there is an unpredictable loss of function of the joint.
Littler (1964) advised tenodesis of the ulnar lateral band of the extensor apparatus to the flexor sheath. The lateral band is sectioned proximally at its musculotendinous level and split away as a cord from the extensor apparatus, but leaving intact its terminal insertion. Then it is passed volar to the axis of rotation of the proximal interphalangeal joint and volar to the proximal portion of Cleland’s ligament. Fixation is to the fibrous tendon sheath of the flexors. In this type of operation the extensor apparatus is affected, making a unilateral lock preventing hyperextension of the proximal interphalangeal joint. A modification is to reroute the lateral band under Cleland’s ligament, or through a “window” in the digital fibrous sheath. Here meticulous suturing of the band to its original origin is necessary to restore the normal function of the finger movement and to prevent recurrent hyperextension or creation of a slight Boutonniere phenomenon. In fact there is a high risk in compromising the normal flexion/ extension mechanism.
Another modification concerns the use of the lateral band released at the proximal site and passing it over the volar aspect of the joint, between the volar plate and the flexor group. The freed end of the lateral band is sutured at the junction of bone and fibres of the fibrous flexor sheath on the contralateral side of the proximal phalangeal shaft.
The dermodesis-technique by removing a volar part of the skin near the joint is a simple but logical method, disregarding the pathophysiological basis of the swanneck deformity.
242
Finally, Moberg and Stener (1953) recommended arthrodesis, if the rupture volar plate cannot be reattached by means of a pull-out wire technique. In our opinion an arthrodesis is the last resort (Boyes, 1970) to be employed when osteoarthritis and failure of previous operations give rise to a painful contracture of the proximal interphalangeal joint. In summary, all the techniques as described above have some disadvantage due to disturbing the normal anatomy, resulting in deforming forces and limitation of motion. McCue (1970) stated that as long as the technique only limits the last ten or fifteen degrees of extension, the result is satisfactory. In our opinion, however, any compromise with the loss of function has to be seen as undesirable and has to be avoided. Our operation strategy provides a simple technique by which we hope to correct the congenital and posttraumatic swanneck deformity without changing in essence the normal anatomy and physiology of the extensor and ‘flexor apparatus and leaving a full range of motion of the finger. Our results in this short series are very encouraging. Long-term results are not yet available. Acknowledgement
We are grateful to Dr A. J. Tonino for allowing report these cases.
US to
References
ADAMS, J. P. (1959). Correction of Chronic Dorsal Subluxation of the Proximal Interphalangeal Joint by Means of a Criss-Cross Volar Graft. The Journal of Bone and Joint Surgery 41A: 1: 111-115. BATE, J. T. (1945). An Operation for the Correction of Locking of the Proximal Interphalangeal Joint in Hyperextension. The Journal of Bone and Joint Surgery 27A: 142-144. BOWERS, W. H. (1978). The post-traumatic “Swanneck’‘-finger-Two common causes. North Carolina Medical Journal 39: 171-172. BOYES, J. H., in Bunnell’s Surgery oftheHand, Fifth Edition, Philadelphia and Montreal. J. B. Lippincott Company (1970) p. 475. EDMONDSON-CRENSHAW, Campbell’s Operative Orthopaedics, Sixth Edition. C. L. Mosbv Comuanv (1980) o. 214-215. KAPLAN, E. B. (1936). &tensibn I%form%es of the Proximal Interphalangeal Joints of the Fingers. An Anatomical Study. The Journal of Bone and Joint Surgery 18: 781-783. KLEINERT, H. E. and KASDAN, M. L. (1965). Reconstruction of Chronically Subluxated Proximal Interphalangeal Finger Joint. The Journal of Bone and Joint Surgery 47A: 5: 958-964. LANDSMEER, J. H. F. (1958). A Report on the Co-ordination of the Interphalangeal Joints of the Human Finger and its Disturbances, Acta Morphologica Nerlando-Scandinavica 2: 59-84. LITTLER, J. W. (1964). The finger extensor mechanism. Surgical Clinics of North America 47: 415-432. MOBERG, E. and STENER, B. (1953). Injuries to the Ligaments of the Thumb and Fingers. Diagnosis, Treatment and Prognosis. Acta Chirurgica Scandinavica 106: 166-186. McCUE, F. C., HONNER, R., JOHNSON, M. C. and GIECK, J. H. (1970). Athletic Injuries of the Proximal Interphalangeal Joint. The Journal of Bone and Joint Surgery 52A: 5: 949-950. PORTIS, R. B. (1954). Hyperextensibility of the Proximal Interphalangeal Joint of the Finger Following Trauma. The Journal of Bone and Joint Surgery 36A: 1141-1146. WEEKS, M. Management of acute hand injuries. First Edition. St. Louis. The C. V. Mosby Company (1973) p. 158-159. ZANCOLLI, E. Structural and Dynamic Bases of Hand Surgery, Philadelphia and Toronto. J. B. Lippincott Company, 1st Ed. (1979) p. 71-73.
THE JOURNAL OF HAND SURGERY
VOL.
11-B No.
2 JUNE
1986
De Wever
Ziekenhuis,
The first patient was a sixteen-year-old, right-handed housemaid. She fell on her outstretched hand, resulting in a hyperextension trauma of the proximal interphalangeal joint of the middle finger of her right hand. The finger had a swollen joint with painful function. The swelling in the joint diminished in a couple of weeks and a gradually progressive hyperextension developed. There was a hyperextension of more than twenty degrees with locking and pain in the proximal joint of her middle finger. Operative correction of this swanneck deformity as described later, was performed four months after trauma. At operation only a thin fragment of the volar plate was found. Reattachment was not possible. Six weeks after operation the middle finger had full function of both interphalangeal joints, without hyperextension or extension lag. At clinical examination twenty-six months after operation the middle finger had a complete, normal and painless range of motion, without hyperextension of the proximal joint. The hand had a normal grip strength and normal fine finger movements. The second patient was a twenty-four-year-old, righthanded operator in the chemical industry. Eight months before his first visit there was a sport trauma of the ring finger of his left hand. Afterwards hyperextension of more than twenty degrees developed in the proximal joint of this finger with a locking phenomenon and discomfort. The ring finger had a full flexion range without pain, with normal grip strength and normal fine finger movements. There was no collateral instability. At operation eight months after the initial trauma, a scarred volar plate was found. The scar tissue did not affect the flexion range. After volar plate reconstruction following our technique, the finger regained normal flexion/extension range within eight weeks. There was no pain, no hyperextension or loss of grip strength. The fine finger movements were normal. 239
R. P. KARTHAUS AND G. J. I. M. van der WERF
At follow-up, twenty-seven months after operation, clinical examination showed the same results. The third patient was a fifteen-year-old, right-handed schoolgirl. From her early childhood there was a hyperextension of the proximal interphalangeal joints of all fingers. Since ten months a progressive locking of the joints in hyperextension developed in the index, middle and ring fingers of both hands. Active flexion could not be initiated in this position. Trying to do so gave rise to pain and more hyperextension. The flexion range was normal. Grip strength and fine finger movements were unaffected. Following our technique, the index, middle and ring fingers of both hands were operated on. Three months later the function of all but one finger showed full extension, without hyperextension. The index finger of the right hand had a five degrees extension lag. Flexion of all fingers was normal. Grip strength and fine finger movements had been unchanged. At follow-up of twenty-five months the condition of the six fingers has not changed. Grip strength is perfect. Fine finger movements are normal. There is only a minimal scar visible at the ulnar aspect of the proximal joint of the operated fingers. All the three patients were very satisfied with the results of the operation. There were no complications. All patients returned to their previous work within six weeks after operation. Operative Technique
Through a curved ulnar skin incision over the proximal interphalangeal joint expose and define the ulnar superficialis tendon slip. Avoid damage to the ulnarvolar neuro-vascular bundle. Split the ulnar superficialis tendon in equal parts, about one centimetre proximal to its insertion. Dissect the most ulnar part proximally forming a distal based slip of three centimetre length. Expose the volar aspect of the proximal phalanx. Inspect the volar plate (remnants). If necessary excise abundant scar tissue. Next drill a two millimetre hole in the proximal phalanx in a volar-dorsal direction, a few millimetres proximal to the joint and its synovial extent. Carry the freed half of the superficialis slip with an absorbable suture fixed at the end to the proximal ~phalanx. Thread it through the hole in the phalanx. Anchor the tendon slip in the proximal phalanx tieing the suture over a button on the dorsum of the finger, keeping the joint in fifteen degrees of flexion (Figure 1). Close the wound with interrupted absorbable sutures. Splint the finger with the joint in fifteen degrees of flexion. 240
Fig. 1
Modified Curtis technique of correcting hyperextension and locking of the proximal interphalangeal joint of the finger.
After three weeks the splint is removed, the suture on the dorsum of the finger is cut off and active exercises are begun. If necessary a nightsplint can be worn for a few weeks. In six to eight weeks the extension restriction of fifteen degrees subsides by normal exercise, leaving a full range of motion without deformity of the proximal interphalangeal joint. Discussion
Swanneck deformity represents a troublesome pathology of the finger, which may be produced by multiple causes. It is clinically characterised by recurvation of the middle joint and a flexed position of the distal joint. Normally the proximal joint cannot exceed ten degrees of hyperextension (Weeks, 1973). In swanneck-deformity the middle joint recurvation secondarily produces the opposite deformation of the distal joint. This functional relationship between the .,r,srphalangeal joints is also manifested by the magnitude of the deformity, since the greater the recurvation of the middle joint, the greater the flexion of the distal joint. According to the cause, which initiates the deformity Zancolli (1979) has classified three fundamental types of swanneck deformities: the extrinsic, intrinsic and articular type. The initial factor of the extrinsic type concerns an overaction of the long extensor tendon due to pathological flexion positions of the wrist and/or metacarpophalangeal joints, or tendinous adhesions or muscular shortening and spasticity (extensor plus finger). The intrinsic type of swanneck deformity can be produced in all cases in which there is an imbalance of THE JOURNAL OF HAND SURGERY
CONGENITALSWANNECKDEFORMITY
extensor/flexor activity with relative overaction of the intrinsic muscles due to ischaemic retraction, spasticity, rheumatic disease etc. The third type, the articular type, is caused by failure of any of the principal stabilisers of the joint. This may allow the beginning of recurvation of the joint by abnormal traction of the digital extension forces. The rest of the stabilising structures begin to give in. So the recurvation progresses, while the distal joint is immediately placed in a flexed position, losing its capacity of active extension. The principal causes of the loss of stabilising structures of the joint are: 1. direct injury of the volar plate or 2. elongation of the volar plate by rheumatic disease, 3. lack of superficialis tendon due to trauma or surgery, 4. elongation or destruction of the oblique laminae of the lateral retinacular ligaments, which favours pathological dorso-medial migration of the lateral extensor tendons, 5. hypertrophic, retractile scar over the dorsum of the joint and 6. congenital joint laxity. Lastly a swanneck deformity is possible in case of a mallet finger, in which the normal relationship of flexor-extensor in the proximal joint is disturbed by an extensor tendon lesion at the distal joint (Bowers, 1978). Restoring the normal anatomical relationship between extensor and flexor mechanism is in fact the only way of management of the swanneck deformity. Actually in the direct traumatic injury of the volar plate and in congenital joint laxity the lesion concerns only one simple structure, without damage to the flexor or extensor apparatus, resulting in a swanneck deformity. The latter two are very accessible for operative treatment. In longstanding cases of traumatic volar plate rupture, reconstruction of the volar plate using the original tissue is often impossible by retraction of the rests of the volar plate and scar formation. Sometimes this hypertrophic scar tissue inhibits the normal flexion range. At reconstruction of the volar plate this scar tissue has to be excised. The use of half of the ulnar slip will not change the normal superficialis physiological loading of the proximal interphalangeal joint. There will be no imbalance of force generated by the superficialis tendon. The extensor apparatus will be unaffected. The absorbable “pull-out” suture does not counteract the normal action of the extensor hood. The freed slip acting as an extension-inhibitor will be relaxed when the proximal joint is flexed (Figure 2). So there will be no restriction of flexion by the rerouted part of the superficialis slip. This part of the slip is capable of withstanding (hyper)extension in the proximal joint.
Inhibiting the hyperextension, the freed slip of the superficialis runs in a slightly diagonal direction, but the resultant force acting on the proximal joint will produce only a minimal torsion on the joint in full extension. VOL. 11-BNo. 2 JUNE 1986
Fig. 2
In flexion of the proximal interphalangeal joint the freed and rerouted superficialis slip has been withdrawn in a proximal direction.
This is in contrast with the Curtis technique (Edmondson-Crenshaw, 1980), where the whole superficialis slip is used, which runs diagonally over the joint, possibly resulting in an asymmetric flexor force acting on the base of the middle phalanx, and generating torsional stress on the proximal interphalangeal joint in full extension. Furthermore the loss of the ulnar superficialis tendon slip may allow easier hyperextension in the joint (Kaplan, 1936) by loss of the hyperextension-inhibiting effect of this part of the superficialis tendon. Bate (1945) described an operative technique suturing the contracted volar ligament to the anterior part of the proximal phalanx and shortening the anterior portion of the lateral capsule. This procedure gives rise to an extension lag of twenty degrees or more. This result may be acceptable, but still there is a restriction of extension. Further it changes the normal structure of the lateral capsule into a pathological one. Portis (1954) stated that the reattachment of the volar plate may be sufficient in treatment of the traumatic volar plate rupture with swanneck deformity. If this is not possible, because little or no volar plate can be found to repair, some other technique has to be used as replacement of the destroyed volar plate. Bunnell (Boyes, 1970) described a tendon graft to replace the volar plate. Following this technique Adams (1959) operated three fingers in two patients. One finger regained a full range of motion. The other two had a restriction of extension of five and twenty-five degrees respectively. One finger had a slight limitation of flexion in the follow-up. In this “criss-cross” technique 241
R. P. KARTHAUS AND G. J. I. M. van der WERF
there is a need for an ulnar and radial exposure as well. In extension the volar synovium of the joint may be damaged, forming scar tissue, resulting in limitation of flexion and/or extension.
Kleinert and Kasdan (1965) reported four cases. They reattached a portion of the collateral ligament more proximally to prevent full extension of the proximal joint. In three patients there was a minor loss of extension of five, ten and twenty degrees respectively. They used a bilateral approach to the joint, altering a normal structured collateral ligament to a collateral ligament with an abnormal origin. The overall result of this operation may be acceptable to excellent, but there is an unpredictable loss of function of the joint.
Littler (1964) advised tenodesis of the ulnar lateral band of the extensor apparatus to the flexor sheath. The lateral band is sectioned proximally at its musculotendinous level and split away as a cord from the extensor apparatus, but leaving intact its terminal insertion. Then it is passed volar to the axis of rotation of the proximal interphalangeal joint and volar to the proximal portion of Cleland’s ligament. Fixation is to the fibrous tendon sheath of the flexors. In this type of operation the extensor apparatus is affected, making a unilateral lock preventing hyperextension of the proximal interphalangeal joint. A modification is to reroute the lateral band under Cleland’s ligament, or through a “window” in the digital fibrous sheath. Here meticulous suturing of the band to its original origin is necessary to restore the normal function of the finger movement and to prevent recurrent hyperextension or creation of a slight Boutonniere phenomenon. In fact there is a high risk in compromising the normal flexion/ extension mechanism.
Another modification concerns the use of the lateral band released at the proximal site and passing it over the volar aspect of the joint, between the volar plate and the flexor group. The freed end of the lateral band is sutured at the junction of bone and fibres of the fibrous flexor sheath on the contralateral side of the proximal phalangeal shaft.
The dermodesis-technique by removing a volar part of the skin near the joint is a simple but logical method, disregarding the pathophysiological basis of the swanneck deformity.
242
Finally, Moberg and Stener (1953) recommended arthrodesis, if the rupture volar plate cannot be reattached by means of a pull-out wire technique. In our opinion an arthrodesis is the last resort (Boyes, 1970) to be employed when osteoarthritis and failure of previous operations give rise to a painful contracture of the proximal interphalangeal joint. In summary, all the techniques as described above have some disadvantage due to disturbing the normal anatomy, resulting in deforming forces and limitation of motion. McCue (1970) stated that as long as the technique only limits the last ten or fifteen degrees of extension, the result is satisfactory. In our opinion, however, any compromise with the loss of function has to be seen as undesirable and has to be avoided. Our operation strategy provides a simple technique by which we hope to correct the congenital and posttraumatic swanneck deformity without changing in essence the normal anatomy and physiology of the extensor and ‘flexor apparatus and leaving a full range of motion of the finger. Our results in this short series are very encouraging. Long-term results are not yet available. Acknowledgement
We are grateful to Dr A. J. Tonino for allowing report these cases.
US to
References
ADAMS, J. P. (1959). Correction of Chronic Dorsal Subluxation of the Proximal Interphalangeal Joint by Means of a Criss-Cross Volar Graft. The Journal of Bone and Joint Surgery 41A: 1: 111-115. BATE, J. T. (1945). An Operation for the Correction of Locking of the Proximal Interphalangeal Joint in Hyperextension. The Journal of Bone and Joint Surgery 27A: 142-144. BOWERS, W. H. (1978). The post-traumatic “Swanneck’‘-finger-Two common causes. North Carolina Medical Journal 39: 171-172. BOYES, J. H., in Bunnell’s Surgery oftheHand, Fifth Edition, Philadelphia and Montreal. J. B. Lippincott Company (1970) p. 475. EDMONDSON-CRENSHAW, Campbell’s Operative Orthopaedics, Sixth Edition. C. L. Mosbv Comuanv (1980) o. 214-215. KAPLAN, E. B. (1936). &tensibn I%form%es of the Proximal Interphalangeal Joints of the Fingers. An Anatomical Study. The Journal of Bone and Joint Surgery 18: 781-783. KLEINERT, H. E. and KASDAN, M. L. (1965). Reconstruction of Chronically Subluxated Proximal Interphalangeal Finger Joint. The Journal of Bone and Joint Surgery 47A: 5: 958-964. LANDSMEER, J. H. F. (1958). A Report on the Co-ordination of the Interphalangeal Joints of the Human Finger and its Disturbances, Acta Morphologica Nerlando-Scandinavica 2: 59-84. LITTLER, J. W. (1964). The finger extensor mechanism. Surgical Clinics of North America 47: 415-432. MOBERG, E. and STENER, B. (1953). Injuries to the Ligaments of the Thumb and Fingers. Diagnosis, Treatment and Prognosis. Acta Chirurgica Scandinavica 106: 166-186. McCUE, F. C., HONNER, R., JOHNSON, M. C. and GIECK, J. H. (1970). Athletic Injuries of the Proximal Interphalangeal Joint. The Journal of Bone and Joint Surgery 52A: 5: 949-950. PORTIS, R. B. (1954). Hyperextensibility of the Proximal Interphalangeal Joint of the Finger Following Trauma. The Journal of Bone and Joint Surgery 36A: 1141-1146. WEEKS, M. Management of acute hand injuries. First Edition. St. Louis. The C. V. Mosby Company (1973) p. 158-159. ZANCOLLI, E. Structural and Dynamic Bases of Hand Surgery, Philadelphia and Toronto. J. B. Lippincott Company, 1st Ed. (1979) p. 71-73.
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