Brunner Incison Original

SURGICAL EXPOSURE OF FLEXOR TENDONS IN THE HAND JULIAN M. BRUNER M.D., F.A.C.S. Des Moines, Iowa, U.S.A.

THE TERMS OF reference of this lecture are that it shall be concerned with some subject allied to plastic surgery in which the speaker has had experience. I have chosen to discuss the surgical exposure of flexor tendons in the hand. My experience of this subject has been acquired in army hand centres and in practice for 25 years in the capital city of a mid-western American state where my father began his medical and surgical practice in 1893. Injuries of the hand occur frequently herein the home, in the factory, and on the farm. Tendon repair in general has been successful for many years. Accurate suture of the cut tendon, with appropriate splinting to avoid dehiscence until strong union occurs, is generally followed by good results. On the flexor side of the hand, however, such is not the case. The reasons are anatomical and functional. At the base of the digits anld at the wrist tight retinacula hold the flexor tendons in their course during flexion. A second factor militating against successful repair is the long excursion of these tendons (2-3 in (5.1-7.6 cm)), anything short of which means disabilty of that finger. A third factor present in the digit (but not in the wrist) is the tenuous and vulnerable blood supply available to the flexor tendons through the slender vincula. These three factors have conspired to make flexor tendon surgery in the hand difficult. Recent improvements in technique, however, have led to better results. Among these is the use of new incisions to gain better exposure. Primary flexor tendon repair in the distal digit, in the proximal palm, and in the forearm is generally successful; therefore this discussion will be limited to the two retinacular regions where success is elusive: No Man's Land at the base of the digit and the carpal tunnel zone at the wrist. The late Dr. William J. Mayo, whom I assisted years ago, often stressed the importance of wide abdominal exposure to view the pathological anatomy and to perform the operation. Good exposure is even Second part of the sixth Mclndoe Lecture delivered at the Royal College of Surgeons of England on 7th December 1972 at the meeting of the British Association of Plastic Surgeons

(Ann. Roy. Coll. Surg. Engl. 1973, vol. 53)

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SURGICAL EXPOSURE OF FLEXOR TENDONS IN THE HAND

more pertinent in the hand, where structures are small and access difficult. In 1950, on the invitation of Sir Archibald Mclndoe, I attended the meeting of the British Association of Plastic Surgeons at Hill End, St. Albans, under the presidency of Mr. Rainsford Mowlem. After the meeting I spent some time at East Grinstead and presented a short paper before the house staff of the Queen Victoria Hospital on the subject of 'Incisions for non-septic surgery of the hand'. (This paper was later read before the house staff of the Royal Infirmary, Edinburgh, at the invitation of Sir James Learmonth, one of my surgical chiefs at the Mayo Clinic, and was published in the British Journal of Plastic Surgery in 19511.) In this article I presented ideas current in 1950 regarding surgical exposure in the hand and described the dilemma of the surgeon who was attempting with great frustration to expose longitudinal structures through transverse incisions, to conform with the skin creases. These limited crease incisions, although leaving fine scars, were a handicap in obtaining necessary exposure. As an example of how progress was retarded, let us recall the exposure used for fasciectomy in Dupuytren's disease. At that time many of us performed this operation through an incision in the distal palmar crease supplemented by separate incisions on the finger. This meant a difficult and obscure dissection with extensive undermining of the skin. Today fasciectomy is done through continuous digitopalmar incisions which give excellent exposure of the hyperplastic fascia in the region of the joints where contracture occurs. They are often zig-zag incisions, or longitudinal incisions, converted by Z-plasty in the finger and in the palm as suggested by McGregor. Exposure of flexor tendons in the digits Primary repair. For primary repair of the flexor tendons we must have early, clean, incised wounds, commonly seen after lacerations caused by broken glass and sharp metal. The surgeon presented with such a wound on the volar surface of the finger must decide how best to obtain additional exposure for local resection of the digital theca, tendon repair, and nerve suture. In oblique wounds additional exposure is obtained by proximal and distal bayonet extensions just anterior to the neurovascular bundle. Transverse wounds on the finger pose a greater problem. These also may be extended by bayonet incisions, but if one digital artery has been severed or thrombosed, the distal extension must be on the same side as the injured artery or a skin slough may occur. Transverse wounds of the finger should not be enlarged by zig-zag extensions immediately 85

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adjacent to the wound of injury. To do so creates skin flaps with acute angles, and skin necrosis may occur if blood supply is compromised. If both neurovascular bundles are severed, both nerves and one artery should be sutured if possible. In such a finger tendon repair should then be deferred for later grafting.

Fi-. 1. Extension of wounds for primary flexor tendon repair.

Elective surgery. For elective surgery the Bunnell mid-lateral incision has been standard. The volar digital skin remains intact, and the incision heals with an acceptable scar. However, this lateral approach leaves much to be desired, because: (1) the dorsal branches of the digital nerve must be severed, or they remain in the way; (2) the lateral 86

SURGICAL EXPOSURE OF FLEXOR TENDONS IN THE HAND

approach to the flexor tendon may injure the collateral and retinacular ligaments; (3) if the incision is extended into the palm it must cross the neurovascular bundle; and (4) it is awkward to work between fingers or on the ulnar side of the thumb. In 1965 I departed from the traditional mid-lateral approach and moved to the volar skin. This was prompted by an accidental zig-zag glass cut on the finger of a young student sustained while bar-tending. The exposure provided by this ready-made incision was so good, the result of primary tendon repair in No Man's Land so successful, and the subsequent scar so favourable that I decided to use this staggered approach for other flexor tendon repairs. Such a volar approach is direct, does not encroach on the neurovascular bundle, and may be extended into the palm as far as necessary. The digital theca is thereby widely exposed so that it can be partially excised (for either primary repair or tendon grafting), leaving whatever pulleys are necessary in the finger to prevent bow-stringing of the tendon or graft. In 1967 I reported the use of this incision at the Anglo-Scandinavian Symposium of Hand Surgery in Lausanne and Vienna2. Three years later at the joint meeting of the American and Scandinavian Hand Societies in Finland, Sweden, and Holland I was pleased to find that this method of exposure of the flexor tendons was frequently being used by surgeons in those countries. There has been some difference of opinion as to the exact delineation of the volar zig-zag incision. All agree that the hinges should be at the skin creases of the finger and palm. However, some have placed the hinge in the mid-lateral line of the finger. I believe that the incision should extend only to a point directly anterior to the neurovascular bundle and should not encroach upon or even expose it, thus inviting injury. The angle at the hinge should be somewhat less than 135 degrees. Some surgeons have doubled the number of zig-zags in each finger segment, reducing the angle to about 90 degrees, thus making the skin serrations sharper. In the distal segment of the finger or thumb the incision should skirt the proximal edge of the digital nerve as it fans out to supply the pulp, thus leaving intact sensation in the finger pad. At the end of the incision, just proximal to the vortex of the finger print, direct access is given to the insertion of the profundus tendon-especially important in tendon grafting. Proximally the zig-zag course may be extended into the palm and to the thenar crease; thence to the wrist if necessary. Two other American surgeons were pioneers in the use of this incision: Dr. J. W. Littler of New York and Dr. L. D. Howard of San Francisco. The latter once remarked: 'The volar zig-zag incision on the finger just had to come.' 87

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In my experience, scars resulting from this incision have been acceptable and no changes in sensation of the volar digital skin have been noted. Flexion contractures have not resulted. If they occur, they may be due to injury of the volar plate or to improper postoperative splinting. The little finger especially has a strong tendency to curl up, shrimp-like, at its interphalangeal joints. This must be prevented by splinting these joints in extension as recommended by J. I. P. James.

Exposure of flexor tendons at the wrist We turn now to the exposure of flexor tendons at the wrist. Their repair in the carpal tunnel zone has often been attended with difficulty, as it has in No Man's Land. The carpal canal, containing nine flexor tendons and the median nerve, is normally snug, and when swelling occurs in the synovial tissues, as it frequently does in menopausal women, pressure is exerted on the median nerve, with resulting

paraesthesiae. Decompression of the median nerve for 'carpal tunnel syndrome' was first done by James Learmonth in 1930 at the Mayo Clinic on a patient with arthritis of the wrist. He used a short transverse incision through which he divided the transverse carpal ligament, with dramatic relief of

symptoms. It was not until about 1950, however, that this operation came into general use. We have since learnt that wider exposure of the carpal canal is advisable to avoid injury to the median nerve and its motor and sensory branches. The incision commonly used is longitudinal, with a small zig-zag at the wrist level to minimize the scar. In my experience, section of the volar retinaculum has been without complication. Bow-stringing of the flexor tendons does not follow as it does on the back of the wrist when the dorsal retinaculum is severed. If one explores this region one or two years later, he finds that the transverse carpal ligament has been reconstituted. Such wide exposure has not yet been exploited for the repair of tendons injured within or near the carpal canal. Many surgeons still regard the flexor retinaculum with some awe and go to great lengths not to sever it. The transverse carpal ligament is a bridge under which the flexor tendons ebb and flow, but like the Tower Bridge in London it may be opened, and in due course it will close itself (Fig. 2). Primary repair. During the past five years I have opened the carpal canal widely for the primary repair of tendon injuries. The transverse carpal ligament is transected, distally the palmar fascia is incised, and proximally the antebrachial fascia is freely divided. With such wide exposure, multiple tendons severed within or near the canal may be quickly identified, matched, and repaired, also the median nerve if it is injured. 88

SURGICAL EXPOSURE OF FLEXOR TENDONS IN THE HAND

The antebrachial fascia and the transverse carpal ligament should never be sutured. The palmar fascia should be excised locally in the region of tendon suture to prevent adhesions (Potenza). A word of warning! Oblique wounds on the volar surface of the wrist may usually be connected with the standard carpal tunnel incision,

Fig. 2. Surgical exposure of flexor tendons.

but with transverse wounds of the wrist a cruciate incision must be avoided, or sloughs may occur in the distal flaps. If there is any question of adequate blood supply, a bridge of intact skin should be left just distal to the transverse wrist wound under which the transverse carpal ligament may be incised (Fig. 1). 89

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In many textbooks the surgeon is advised to suture only the profundus flexor tendons if all are cut under or near the transverse carpal ligament. I believe the sacrifice of the sublimis tendons, so indispensable for individual flexion of the fingers, is destructive and unnecessary. For some time now, with wide exposure of the carpal canal, I have repaired all flexor tendons cut within or adjacent to it, both profundus and sublimis. They heal well and adhesions that occur are gradually mobilized by individual finger motions. Cross-union of profundus and sublimis flexor tendons has not been a problem in my experience. If such union should persist, tenolysis is available.

Elective surgery. Incisions for elective surgery at the wrist level are often limited to short transverse or L-shaped incisions proximal to the transverse carpal ligament. These will suffice for elective surgery on one or two tendons. If many tendons are involved, the standard carpal tUIlnel incision may be necessary.

Discussion Much experimental work has been done in recent years in regard to the blood supply of the cut tendon and the mechanism of healing. We know that a callus of fibroblastic tissue occurs at the site of suture and that healing comes largely from peripheral cells in the wound and not from the cut ends of the tendon. After a flexor tendon is cut in the finger it is often prevented from retracting by the vincula, in which fine blood vessels are then subjected to strong muscle traction for hours or days, with possible thrombosis. If this happens, a segment of the sutured tendon may actually be an infarct. The tissue reaction to a segment of dead tendon must be intense, and this may explain many a failure after primary repair. It is in such cases that we return to the scene months later to do a tendon graft and will find a congealed conglomerate of cicatrix. In the Bunnell Lecture of 1971 Claude Verdans reviewed the present restatus of flexor tendon surgery in the hand, including both primary cut are tendons flexor both when that He believes pair and grafting. in No Man's Land removal of the sublimis tendon, which has been the standard practice for many years, may injure the blood supply ofsubboth has sutured he in which profundus tendon. He reports cases limis and profundus tendons in No Man's Land with excellent results. in No My experience in the carpal tunnel zone is similar to Verdan'sretained be successfully may tendons the sublimis Man's Land-that is, and repaired. This suggests that a technique practised for many years of needs to be reexamined. It may be that in the future the sacrifice ancient an the sublimis tendon in both areas will be remembered as pagan rite still practised by hand surgeons in 1972. 90

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SURGICAL EXPOSURE OF FLEXOR TENDONS IN THE HAND

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(b)

Fig. 3. Tendon graft, both flexors little finger (4 months post-injury). (a) Preoperative. (b) Zigzag volar incision. (c) P.L. graft in place (d) Post operative-hand open. (e) Postoperative-hand closed.

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Conclusion During the past 25 years flexor tendon repair in the hand has made significant advances. Flexor tendon grafting has been brought to a highly successful level, as evidenced by the admirable series reported by Guy Pulvertaft4 and by Joseph Boyes. Primary repair, so long in the doldrums but so advantageous to the patient, now shows great promise. More successful primary repairs are now being done and the status of briefly delayed primary repair is being defined. Improved techniques are contributing to these advances. Among these are incisions which give better exposure. Although some surgeons may regard the serious discussion of incisions as elementary, such is not the case in the hand. The correct incision, indelibly inscribed on the skin, is a plan of battle. It may portend victory or defeat from a skin slough, or condemn the surgeon to a two-hour arduous repair which might have been completed in one hour. Unfortunately many incorrect incisions are depicted in textbooks and the error perpetuated through several editions. Examples of this are misleading incisions recommended for the relief of carpal tunnel syndrome or de Quervain's disease which expose sensory nerves to injury, often with serious disability. The volar zig-zag incision, previously proscribed but used now for more than five years by many surgeons, is a dependable alternative to the standard mid-lateral digital incision and greatly facilitates elective flexor tendon surgery. The carpal tunnel incision, until recently used only to decompress the median nerve, is now being exploited for the rapid primary repair of multiple tendons sevefed at the wrist. Finally, if we are to make real progress in flexor tendon surgery, the surgeon who does primary repair and the surgeon who does tendon grafting must actually be one and the the same person. The future of hand surgery. And what of hand surgery in the future? Today in Britain and in America it is being done by plastic, orthopaedic, and general surgeons. In this context it is a subspecialty, but it may not remain so. The scope of hand surgery is expanding. Surgery for rheumatoid disease of the hand is an important branch, developed during recent years. My colleague in Iowa City, Adrian Flatt, is one of several surgeons well qualified in this field who are mercifully correcting the deformities of these crippled hands. Microsurgery applied to the repair of small arteries and nerves is another recent development, and it appears likely that hand surgeons of the future must be skilled in the use of the operating microscope. The accomplishments of Cobbett of East Grinstead, O'Brien of Melbourne, and James W. Smith of New York are impressive. 92

SURGICAL EXPOSURE OF FLEXOR TENDONS IN THE HAND

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finger..(a) ~~~ Peerte.. (b)Fin Fig. 4. Primary repair, both flexors little~~~~~~~~~~~~~

c )~ ~ ~ ~ ~ ~ ~ ~ ~ C Fig. 4. Primary repair, both flexors little finger. (a) Preoperative. (b) Fingers extended. (c) Fingers flexed.

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JULIAN M. BRUNER

As trauma increases in modem life, traumatic hand surgery expands, requiring expertise in bone, nerve, and tendon repair. This suggests that hand surgery should be a specialty in its own right. A few surgeons located in the large cities of America confine themselves to surgery of the hand, and a good case can be made for such limitation. If one visits the clinics of these surgeons, he will at once appreciate the high level of their clinical judgement and technical skill. It is likely, however, that for some years ahead hand surgery will remain a subspecialty. The chief problem is to develop training centres and to determine the scope and length of such training. The study of anatomy, now lamentably de-emphasized in some medical schools and postgraduate programmes, must on the contrary, be reinforced by repeated dissections. The Royal College of Surgeons of England and its sister Colleges have traditionally fostered the highest standards of anatomical knowledge. This must be maintained especially in surgery of the hand, where the precise knowledge of normal and anomalous structures is of critical importance. The desire of surgeons to avoid scars on the volar surface of the fingers, hand, and wrist is commendable, but experience has shown that exposure of the flexor tendons through crease incisions is inadequate. Poor flexor tendon surgery is often the direct result of poor exposure. The function of grasp is by far the most important in the hand and far outweighs cosmetic considerations. However, if reasonable care is used in the closure of zig-zag incisions, they are inconspicuous, as shown by the photos in Figures 3 and 4. In the United States 54 centres for training in surgery of the hand have been listed in a brochure issued by the American Society for Surgery of the Hand. However, these centres have no official approval and the training period has not been agreed upon. I believe it should include at least one year of experience on a service where large numbers of hand cases are seen. At the meeting of the British Society for Surgery of the Hand ill Windsor in May 1972 steps were taken for the development of such centres in Great Britain. The high level of hand surgery in this country is known throughout the world and is due in no small measure to the work of those pioneers in this field of whom Sir Archibald Mclndoe is an outstanding example. REFERENCES 1. BRUNER, J. M. (1951) British Journal of Plastic Surgery, 4, 48. 2. BRUNER, J. M. (1967) Plastic and Reconstructive Surgery, 40, 571. 3. VERDAN, C. (1972) Journal of Bone and Joint Surgery, 54-A, 472. 4. PULVERTAFT, R. G., Personal communication.

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