Melbourne, Australia

Transcription

1 THE REPAIR OF FLEXOR TENDONS IN THE HAND 1 By B. K. RANK, M.S., F.R.C.S., F.R.A.C.S., and A. R. WAKEFIELD, M.S., F.R.C.S., F.R.A.C.S. Melbourne, Australia THIS communication concerns only one intrinsic aspect of the reparative surgery of the hand. In various parts of the world we find reparative surgery of the hand done by various denominations of surgeons and under widely differing systems of organisation : some even make claim to particular designation as hand surgeons. Comparable results under these varied conditions, good, bad, and indifferent, testify that we cannot as yet suggest that this work is the legitimate and exclusive field of any particular set. We can, however, state categorically that hand surgery cannot be departmentalised within itself. It is reduced to its worst by separate and independent considerations of its varied systems. Any who claim to do hand surgery must be proficient in all its ramifications. An outstanding requirement is continuity of management by surgeons fully versed in the art and technique of plastic repair, and it is difficult to see how this can ever be properly developed in any strictly regional application. It is over thirty years since Sterling Bunnell (I918) first elaborated the principle of extra-thecal suture for what seemed a hopeless problem of repairing flexor tendons in the finger region. Despite this long time, success in the application of this principle in any regular manner has come to very few surgeons the world over. It is perhaps significant that wherever success is achieved we find as a dominant factor a thorough working appreciation of the technique of the so-called plastic surgeon. Nevertheless, despite these facts it would seem that if we as a group are to pursue this wide open and important field, as we should, it is high time we showed our results not in terms of individual cases but in some more comprehensive manner. The day has passed when odd successes with flexor tendon repair call for any comment of admiration. It is quite unfair to tell a patient of two successful cases without proper recitation of the twenty-two failures. It is of no service to pursue his management on what other surgeons have done or say they can do. Insurance companies very soon catch up on extravagant claims and outside chances. In Melbourne, taking the view that plastic surgery is none other than a method of surgery to be applied whenever it can be used to a patient's advantage, we have had much opportunity in the field of hand repair over the past ten years. In the early phase of this period, in common with many, we experienced the exasperations of secondary hand repair in the wake of sepsis, long immobilisation, and joint stiffness, with their manifold pernicious sequelm. Under such conditions many of us were often forced to go hard for a chance of slight improvement in a grossly mutilated hand. That was war-time--an era with indications for secondary wound closure and discontinuity of treatment for severe injuries. Civil conditions and 1 The substance of a talk given by Mr B. K. Rank at the Annual Meeting of the British Association of Plastic Surgeons in Edinburgh, September I95I, illustrated by coloured film. 244

2 THE REPAIR OF FLEXOR TENDONS IN THE HAND 245 indications are different. Continuance of the war-time attitude of pushing for slight improvement in the grossly mutilated hand against many odds has from various quarters brought some just and much unjust criticism of the plastic surgeon in hand repair. In contrast to the adverse conditions of war-time, we have since had five years' continued opportunity for the treatment of hand injuries under optimum civilian conditions. This has been used to test and elaborate on available procedures, first by some controlled variation of technique, one surgeon against the other, and later by a common approach on lines which we had found to be most satisfactory. It is not our object to report here our consideration of the generalities of flexor tendon repair ; neither its indications nor the choice of methods or procedures, for these have previously been fully reported in two papers published in the Australian and New Zealand Journal of Surgery (Rank and Wakefield, o; I951-52). Reference to these will indicate the evolution of personal standards in a later series of some sixty-six repairs of flexor tendons in the hand as compared with those set out in an earlier paper. In achieving present standards we regard as dominant a long-term training and apprenticeship as plastic surgeons. In addition, there are certain specific technical aspects of the tendon grafting operation in its application to flexor tendon repair which we consider merit some emphasis, especially as some of them appear controversial in present-day surgical literature. We well realise there are diverse paths to successful accomplishment, and any of us can speak, therefore, only in terms of personal experience. INCISIONS AND EXPOSURE OF THE OPERATING FIELD The advantages of raising a flap and so isolating any area of deep repair from the regions of superficial closure are well known. Application of this principle to a finger, to give a sufficiently radical exposure of the flexor tendon system and permit of atraumatic and precise man0euvres conducive to success with the flexor tendon grafting operation, is not so generally appreciated. A skin and fat flap based on one side of the finger can be raised with safety provided the proper care of design, handling, and after-treatment are applied. Fig. I shows the lines of skin incision and the flap exposure which we have practised without reason for regret. This gives a far better access to the flexor system in the finger than does either a lateral or anterolateral incision and retraction. It permits of full appreciation of the local conditions, precise removal of tendon remnants, proper resection of flexor sheath, and fixing of the distal junction of the graft. It should be noted that the main line of incision is along the neutral line on the side of the finger--a line which joins the extreme side limits of the transverse interphalangeal creases when the finger is flexed. The distal limit of the flap is far enough beyond the distal interphalangeal crease to permit of clear exposure of the insertion of the profundus tendon. The proximal limit of the flap varies in the case of the index and little fingers from that in the case of the middle and ring fingers. The little and index fingers most commonly suffer flexor tendon injuries, and, fortunately, in these fingers the lateral incision can be carried proximally on the lateral margins of the palm to the line of the distal palmar crease, and the proximal margin of the flap is made in this line in each case. This gives a good exposure of the proximal end of the digital theca, proper resection of which we regard as an important factor in the outcome. In the case of the middle and ring fingers the flap should

3 246 BRITISH JOURNAL OF PLASTIC SURGERY not be prolonged into the palm, so that it may be necessary to make a separate small transverse incision in the distal palmar region for access to the proximal regions of the digital theca in the case of these two fingers. The lateral margin of the flap is behind the digital nerve. The flap is cut thin at this edge so that it is actually raised anterior to the digital nerve, after which it is made to include all the tissue bulk in front of the digital theca. The other necessary incisions include (I) a transverse incision in the proximal palm to expose the flexor tendons at the region of origin of the lumbrical muscle ; (2) a long vertical incision proximal to the wrist for exposure and careful removal of the palmaris longus tendon, which we favour as donor source for the graft whenever it is present. In the case of the thumb flexor only the digital flap and wrist incision are generally required. A B FIG. I A~ The exposure used by the writers in the case of the little finger : note the distal and proximal limits of the flap. The means of fixing the hand and the hook retractors which are favoured are also shown. B, After closing the incisions this shows the outline of the flap. The line of the main incision is most important. RADICAL RESECTION OF THE FLEXOR DIGITAL SHEATH We have found that results of flexor tendon grafts have been best when as much as possible of the flexor sheath has been cleanly resected. This especially applies to any area of damage and to the thick proximal portions of the digital

4 THE REPAIR OF FLEXOR TENDONS IN THE HAND 247 theca which extend into the distal palm. It is our practice to leave only two bands of sheath (Fig. I, A), one over each of the proximal two phalanges, to prevent anterior prolapse of the graft. Should these correspond to a region of damage, as the proximal loop frequently does, even this is resected and a retaining loop reconstructed by a piece of the donor tendon complete with its paratenon. This is looped around the phalanx or else sutured to each side of it. If the second loop cannot be retained, no counterpart for this is generally made. It seems that if the proximal retaining loop is too far distal on the first phalanx, some degree of prolapse of the graft across the metacarpo-phalangeal joint occurs during flexion. This detracts from the full range of movement, and the loop is therefore best sited towards the base of the first phalanx. THE CHOICE OF GRAFT Of the many potential donor tendons, for this operation we strongly favour the palmaris longus tendon. It best satisfies two main considerations. It has a thin cross-section and so survives more easily as a live graft, and, of even more importance, it can be easily removed and transferred with its well-developed paratenon intact. The extensor longus tendon to the second toe is regarded as a second donor choice in the easily and clinically demonstrable absence of the palmaris longus. A long incision on the foot involves longer recumbency and hospitalisation. The plantaris tendon is conveniently long and thin, but it is erratic both in its presence and size, and there is no means of predetermining its presence, nor has it such a well-developed paratenon arrangement. The flexor digitorum sublimus tendons have no paratenon and are generally too thick. Our best results using a sublimus tendon are not to be compared with those where the palmaris longus tendon has been used as the graft. To choose deliberately some other donor tendon when the palmaris is present is not only illogical from the point of view of convenience, but indicative of a failure to grasp the important principles which are fundamental to the success of the procedure. THE IMPORTANCE OF THE PARATENON The most mobile grafts are those transferred with an intact paratenon. The degree of excursion of a palmaris tendon graft through its paratenon can be well demonstrated when the graft is in place. The paratenon rapidly adheres to its surroundings. In the absence of paratenon a tendon graft becomes adherent to surrounding soft tissues and can act only by pulling on them. Because of the importance of paratenon to success, the donor tendon must never be stripped or dragged out through a small incision. The necessity for a long forearm incision is obvious (Fig. 2). Furthermore, it is important to see that the paratenon is not drawn concertinafashion to one end of the graft when it is inserted in ks new site. The paratenon should be carefully drawn sleeveqike to the proximal junction and over the distal interphalangeal joint. Adhesions at these points will otherwise abort the through pull of the graft, for a tendon expends its traction effect at its most proximal point of fixation or insertion. 4 B

5 248 BRITISH JOURNAL OF PLASTIC SURGERY THE JUNCTIONS OF THE GRAFT I. The Distal Anastomosis.--We have found it most simple and effective t~ fix the graft to a very short stump of profundus tendon at a point just distal to the distal interphalangeal joint. If a longer stump of profundus tendon is left, the adhesion point is proximal to this joint, so that its independent active flexion is lost. If this point is appreciated FIG. 2 Shows how a palmaris longus tendon is removed complete with its paratenon. The insertion of one of the junction sutures in the tendon before it is sectioned facilitates its subsequent removal and atraumatic handling. it is generally unnecessary to go to the extreme of attaching the graft directly to bone. This raises unnecessary extra technical difficulties and causes undesirable added trauma to the region of the distal interphalangeal joint. There are definite hazards to transfixion of the distal phalanx in the very limited space between joint structures and nail bed. 2. The Proximal Anastomosis.--This should be deep in the palm close to the site of origin of the lumbrical muscle. By actively suturing this small muscle around the graft junction the only adhesion at this point is to a mobile structure (Fig. 3). It is a common mistake for the proximal junction of the graft to be sited too far distally in the palm where it is liable to adhesion to skin and/or other relatively rigid structures. This renders the whole purpose of the operation void. THE TENSION OF THE GRAFT The object is to restore the finger to its normal posture when a graft is finally sutured in place. This means in a degree of flexion which increases from the index to the little finger. Moreover, the finger should maintain its normal posture change and relationship to neighbouring fingers as the wrist is passively flexed or extended. To achieve this it is our practice, having fixed the distal end of the graft and closed the finger incision, to keep the finger in an exaggerated degree of flexion (Fig. 4) while carrying out the proximal anastomosis in the palm wound aided by a traction suture in the profundus tendon. The anastomosis can then be done without slack and without strain. Release of the exaggerated finger posture then usually leaves

6 THE REPAIR OF FLEXOR TENDONS IN THE HAND 249 the finger in normal posture and tension, as can be both seen and felt. It is better to have the graft too tense than too slack. Finesse in this manoeuvre, which is by A B FIG. 3 A, Shows the anastomosis of a palmaris longus graft to the flexor profundus of the index finger. B, Shows the site of anastomosis after it has been enveloped in the lumbrical muscle. When the holding stitch is removed from the profundus tendon the site of anastomosis will retract proximal to the wound. Note that as this is an index finger it is not held in the same degree of flexion as the little finger in Fig. 4. far the most tedious and difficult of the whole procedure, can be developed only by experience. POST-OPERATIVE MANAGEMENT AND AFTER-CARE Meticulous after-care, which must be conducted under the personat supervision of the surgeon, is no less important than the operation itself.

7 250 BRITISH JOURNAL OF PLASTIC SURGERY I. Immobilisation.--There is some divergence of opinion regarding this important aspect of treatment after tendon grafting operations (Pulvertaft, 195o). We are emphatic that the principle of immobilisation is never more important than in this particular application, if the ideal of healing with a midimum of scar A B FIG. 4 These pictures illustrate the means of holding an exaggerated flexion posture of a finger while the proximal anastomosis of the graft is carried out. A retaining stitch is temporarily placed between the finger pulp and distal palm. Note that the finger and wrist incisions are both closed before the proximal anastomosis of the graft is arranged. The holding stitch in the proximal stump of the profundus tendon is well proximal and clear of the junction region. formation and adhesion is to result. Our foremost argument in substantiation of this is in the quality of results obtained (Fig. 5). We have yet to see results following early movement which are comparable. Our experience substantiates the experiment and theory of Koch (I944) and of Mason and Allen (I94I). Furthermore, we have been impressed by the value of immobilisafion in obtaining the

8 THE REPAIR OF FLEXOR TENDONS IN THE HAND 251 minimum of scar formation in surface wounds, and how movement before matured healing is conducive to increased fibrosis--a natural effect which would be expected. Early movements of repaired tendons, despite temporary mobility, must add to the degree of inflammatory reaction, scar formation, and ultimate immobility. All raw surfaces created in the course of operation must adhere in the process of healing. We accept such adhesions and aim only at reducing their effects in two ways : (I) by making sure it is the paratenon and not its contained tendon which adheres over the greater part of the tendon A length, and (2) by so placing the points of tendon union that these two inevitable points of adhesion lie beyond the last joint to be activated and deep in the substance of the lumbrical muscle, which is itself a mobile and elastic structure. These, together with! a minimum of tissue handling and absolute immobility until healing is sound, are the principles on which we rely. Such principles are basic throughout surgery whenever sound heal- B ing with a minimum of scar is important. It is not only unlikely but extremely improbable that their contravention in this particular field could be anything but a short-lived experiment conducive to results which can be regarded as of the nature of a compromise only. We are strong advocates, therefore, of a period of immobilisation--absolute immobilisation--of approximately three weeks following tendon grafts, after which c active movements are practised and en- couraged. The movement range at first is small and slow to improve, but the story is one of continued improvement, not continued retrogression as commonly follows early movements. We do not accept the rationale and value of secondary tenolysis operations after poorly functioning flexor tendon grafts, and have had scant FIG. 5 This illustrates the standard of result which can be achieved with a free flexor tendon graft. In this case, two months after both tendons to the little finger were severed over the proximal phalanx, a palmaris graft has been used as described. A shows the full extension range. B and C show the active range of flexion. The ability to flex the finger as in C is the acid test for the highest standards of result in such cases. The patient had a full. range of movement two months after operation. These pictures were taken three months after operation. cause to consider such a. procedure. It may be of value for a single local and discrete adhesion, but this is not the usual condition to be found. There are generally a veritable mass of fine adhesions the whole length of the graft.

9 252 BRITISH JOURNAL OF PLASTIC SURGERY By early immobilisation and waiting for a working degree of tendon union, there is little dependence on sutures. Only one fine silk stitch need be used at each anastomosis, and the amount of traumatic handling is therefore minimal. We are more concerned with atraumatic technique than strong sutures : silk is easier to handle than wire. We are averse to the open procedures of pull-out wires, and found the technique uncertain. If, on occasion, the distal stump has to be fixed to bone we do use wire, but as a closed technique and retaining the sutures. 2. The Posture.wExtremes of postures are avoided. The fingers are in slight exaggeration of their normal flexion in the position of rest. The wrist is well flexed, though not completely so. FIG. 6 This illustrates the traction splint used for overcoming any flexion deformity which sometimes develops in early weeks. The essential features are a moulded " perspex " forearm piece to which are attached an adjustable fulcrum and a long spring wire with soft leather finger loop held by an elastic band. 3. A Pressure Dressing is applied to hand and fingers to ensure approximation of all wound surfaces and to obviate h~ematoma and ~edema. The only interference with this is for removal of sutures in the second week. The immobilisation is not disturbed for this purpose. 4. Mobilisation.--During the fourth week active movements of flexion are practised and encouraged in the inner range. Between times the plaster is still worn, but the wrist flexion is gradually bent out of it. After four weeks the plaster is discarded. A physiotherapist aids and encourages active movements for a period depending on the patient and his progress--generally about three weeks. She must be able to induce relaxation and purposeful effort from the relaxed position divorced from spasm and mass action in the whole hand. We have found this most valuable faculty a variable entity among individual physiotherapists. The patient is taught to control proximal joints with his own hand while moving each interphalangeal joint. We have found a round-edged oblong board as described by Bunnell (i 944) of value. Its diarneters are so arranged to fit each interphalangeal joint. After this period personal use and function are encouraged and exercises continued. The rest is left to time. In some cases where there is limitation of extension which is slow to improve, a traction splint designed for the particular joint is applied (Fig. 6). We are shy to use this within six weeks of operation.

10 THE REPAIR OF FLEXOR TENDONS IN THE HAND 253 PROGNOSIS AND PROGRESS From the findings at operation and the effects of the first attempts at movement, it is generally possible to predict the result. The cases which can move in the early phase continue to improve. The rate of recovery varies, and a useful control and working result are generally achieved in six weeks. The final result, however, can rarely be assessed under six months. In conclusion we would state that a flexor tendon graft is an exacting, timeconsuming, and difficult technical exercise, and there is little place in modern surgical endeavour for the occasional meddler in this field. In the present stage of knowledge and practice in this problem, such are the advantages of proper organisation and tried experience, and such are the issues at stake, that it is quite unfair to a patient to compromise with his chances of successful outcome in such a procedure. Let it not be thought that the designation of a plastic surgeon, or of any other, is a sine qua non of proficiency in this work. What we do say is that the knowledge and technique of one properly trained in plastic surgery is a very good basis, indeed, a flying start for one who is prepared to pursue this work, given the scope and opportunity to do so. REFERENCES BUNNELL, S. (1918). Surg. Gynee. Obstet., 26, xo 3. (1944). " Surgery of the Hand." Philadelphia and London : J. B. Lippincott. KocH, S. L. (1944). Surg. Gynec. Obstet., 78, 9- MASON, W. L., and ALLEN, H. (I941). Ann. Surg., Ix3, 424. PULVI~RTAFT, R. G. (195o). Postgrad. med. ft., 8, 8I. RANK, B. K., and WAKEFIELD, A. R. (I949-5o). Austral. New Zeal. ft. Surg., x9, 232. ( ). Ibid., 2x, I35.