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Flexor tendon injuries of the hand
Flexor tendon injuries of the hand
R. Tubiana, J. Beveridge
Flexor tendon injuries cause a particularly disabling compromise of prehensile function. Repair requires a strong collagen 'callus' able to resist powerful muscle traction yet not obstruct gliding planes. Knowledge of tendon micro-anatomy and nutrition has undergone considerable recent change allowing new techniques of repair. Anatomy: Physiology: Pathology Flexor tendons are mostly intrasynovial facilitating gliding but making repair more difficult (Fig. 1). Other problems also prevail. The tendons are long, crossing many joints, and the amplitude of excursion of flexor digitorum profundus (FDP) at the wrist is up to 7cm. 10 9 6
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However over the proximal phalanx only 2cm of tendon movement is necessary for full flexionx. There is an intimate relationship between the tendons of FDP and flexor digitorum superficialis (FDS) and considerable force is exerted by their muscles. Vascularity is precarious, particularly within the digital sheath. Both tendons receive a segmental supply through vincula. There is a short vinculum for each tendon at the ends of the sheath and a long vinculum common to both tendons at proximal interphalangeal (PIP) joint level. Thus the FDP tendon is devascularised by resection of FDS at this level. There are also avascular segments within the digital sheath, one either side of the long vinculum for the FDP tendon and proximal to the chiasma for the FDS tendon 2. These segments receive nutrition from synovial fluid pumped through micro-cannaliculi3'4. Tendon healing is also critical. The extrinsic theory that tendons healed by way of surrounding scar tissues led to prolonged immobilisation to allow these external adhesions to form 5. Tendons do however heal by an intrinsic tenoblastic response 6 and optimal function is achieved when the extrinsic scarring is minimised by way of careful repair of tendon and sheath, followed by immediate mobilisation. Although these tendons are traditionally described as crossing five topographical zones (distal segment, digital canal, palm and thenar eminence, carpal tunnel, wrist) 7'8 (Fig. 2) because of therapeutic similarities the
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Fig. 1 The flexor tendons and pulley system. At the level of the fingers the flexor digitorum superficialis (2) and flexor digitorum profundus (1), are surrounded by a synovial sheath and closely applied to the phalanx by the fibrous sheath. The thickened areas of the sheath correspond to the 5 annular (A1 to A5) and 3 cruciform (Cl to C3) pulleys. (3) Extensor digitorum communis (4) sagittal band (5) (6) (7) volar plates of the metacarpophalangeal (MP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints (8) insertion of the extensor digitorum communis at the base of the proximal phalanx (inconsistent) (9) insertion of the central extensor tendon (10) lateral extensor tendons (11 ) terminal insertion of the extensor tendon: on the base of the distal phalanx. R. Tubiana, MD, J. Beveridge, FRCS, Institut Francais de la Main, Paris
Current Orthopaedics(1986) 1, 91 99 © LongmanGroupUK Ltd.
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FLEXOR T E N D O N I N J U R I E S OF THE H A N D
number can be reduced to three for practical purposes. Zone II, the intermediate zone, corresponds to the portion of the digital sheath which includes both tendons. Zone I, the distal zone, represents the course of the tendons distal to the intermediate zone, while Zone III, the proximal zone, includes the palmar, carpal and wrist regions. Clearly the intimate tendon relations and poor blood supply in Zone II make this the most problematical area.
Clinical features An incised wound is the commonest cause with tendon rupture being much less common and often in association with a frictional or inflammatory process. Terminal F D P avulsion (rugby players injury) is due to sudden DIP joint hyperextension. Partial division of a tendon is evidenced by a tendon sheath haematoma but preservation of active flexion. Complete division of an F D P tendon implies loss of active flexion of the distal phalanx when the middle phalanx is held rigidly. Complete division of the flexor pollicis longus (FPL) tendon implies loss of active flexion of the IP joint of the thumb. Complete division of an FDS tendon is not so easily recognised as an intact profundus can flex all joints. However by maintaining the other fingers passively extended the finger in
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Fig. 2 The topographical classification of the hand adopted by the International Federation of Societies for Surgery of the Hand. The anatomical regions crossed by only the flexor pollicis Iongus (FPL) are preceded by the letter T (thumb).
question will not flex actively at the PIP joint. According to the position of flexion of the digit when the incised wound occurred the tendon laceration may be some distance from the skin wound when the finger is extended.
Surgical treatment of flexor tendon injuries Partial division of flexor tendons. All suspected cases of flexor tendon injury should be explored. No repair is necessary if more than half the transverse diameter is intact, but a running epitenon suture may facilitate subsequent gliding. Smaller flaps should be excised to prevent catching. More than half diameter lacerations should be primarily repaired and mobilised early in the post-operative phase as after a complete laceration repair.
Complete division. The various treatment methods can be grouped into three categories--operations to restore flexor tendon function (advancement, suture, grafting, tenolysis), palliative operations (tenodesis, arthrodesis, tendon transfer, artificial tendon grafting), and amputation. Clearly the optimal procedure is restoration of flexor tendon function but other procedures do have their indications which depend on several factors of which timing of the tendon repair, the presence of associated lesions, the patient's general condition and requirements, the site of the lesion and the surgical facilities are the more important. Timing of repair. The time interval between trauma and repair is important. Primary repair (within 24 h) is performed if the wound is likely to heal by first intention. This implies within 6h of injury (the so called 'golden period') or during the next 18 h if the wound is tidy, has been cleaned, dressed and splinted and the patient put on antibiotics. For those wounds not fulfilling the primary repair criteria secondary repair is carried out within 3 5 weeks provided the wound is clean and soft tissue coverage adequate. Late repair (after 5 weeks) is necessary for the most serious wounds and, because of tendon retraction, the choice lies between graft or palliation. Associated lesions. With a clean wound of both skin and tendon, repair is indicated up to 5 weeks and thereafter a one-staged tendon graft may be performed. For a clean wound, but with associated neurovascular division, primary repair of nerve and tendon is indicated in the first 24h and if both arteries have been divided at least one should be repaired. In the intermediate period (up to 5 weeks) nerve and tendons should be repaired, but at this stage the vessels are irreparable. In the late phase (after 5 weeks) grafting of both nerve and tendon is required. Associated bone or joint injury, if stable, does not alter the above management, but, if unstable or comminuted, the skeleton should be treated primarily and the tendons secondarily. If presentation of such a complex injury
CURRENT ORTHOPAEDICS 93 occurs beyond the first 24h then a silicone rod delayed tendon graft or pedicle graft is necessary. With significant local bone and soft tissue damage treatment is directed to the wound and the tendon is dealt with secondarily. The most severe categories of these may be candidates for primary amputation. If presentation after bone and soft tissue damage is late then local scarring precludes anything more than arthrodesis or even amputation. Status of the patient. Age is an important factor, with younger patients faring better. Lack of co-operation in the under 6-year-old precludes grafting as a method of management 9. In addition the psychological and occupational status of the patient is important along with surgical facilities and experience.
FDP lesions in the distal zone (Zone I) Site of the lesion. At this level only F D P is present and can be either divided or avulsed. If avulsed without a bone fragment the tendon end is sutured directly to bone with the same technique as for a tendon graft. When a fragment of bone is avulsed, the fragment should be replaced using oblique K-wires with the DIP joint in 15 ° of flexion. If the tendon has not retracted past the PIP joint then the vinculum longus will still be intact and thus reinsertion is possible even after several weeks, particularly in young patients. If retraction into the palm has occurred a tendon graft or palliative procedure will be required. If F D P has been divided, but within lcm of its insertion, reinsertion is possible particularly in the young. Undue tension may cause a flexion deformity of the D I P joint or restricted flexion of adjacent F D P tendons. The A4 pulley should be repaired. The tendon end is fixed to bone by a pull-out suture through the split tendon stump, distal phalanx and nail tied over a button (Fig. 3). Wrist, M P joint and PIP joint are maintained at 40 °, 70 °, and 35 ° of flexion respectively. The D I P joint is held in extension with a small splint and passive movement of this joint is started within a few days.
The splint and pull-out sutures are removed after 4 weeks. If the site of division is more than lcm from the tendon insertion primary end to end repair should be performed, although the results are less satisfactory if there is retraction into the palm as the vinculum longus will have been torn. While loss of F D P function with an intact FDS produces only a minimal deficit there is a more substantial loss of power and, in the presence of infection or a crush injury, secondary suture or grafting may be performed depending upon the patient's occupation. Under no circumstances should an intact FDS be sacrificed in order to repair FDP. If repair of F D P is not indicated and P I P joint movement is good then the D I P joint should be stabilised, either by tenodesis to the A4 pulley or the shaft of the middle phalanx, or by capsulodesis if the site of division is too distal. The D I P joint should be stabilised in about 20 ° of flexion and held for 5 weeks by a K-wire. These procedures allow passive DIP joint flexion and thus are preferred to arthrodesis. F D P tenolysis may be necessary if pain in the palm persists, or if active FDS IP joint movement is unsatisfactory. When F D P has not been repaired a lumbrical plus deformity caused by proximal retraction of the lumbricals may occur.
Flexor tendon lesions in the intermediate zone (Zone
II). While it has always been traditional not to recommend primary suture in 'no man's land' this is now the method of choice although failure may place the whole future of the hand at risk. Primary suture is particularly applicable to children and multiple F D P divisions. Certain criteria should be observed 4,v. The wound should be expected to heal by first intention, the associated lesions should be compatible with rapid mobilisation and surgical facilities should be excellent.
Fig. 3 Distal fixation of the graft. The distal end of the profundus tendon stump is divided in the midline; (A) a small gouge is used to raise a flap of bone under the tendon; (B) a hole is then drilled through the bone so that it exits through the nail, distal to the lunula. A needle is then passed, blunt end first through this hole, to pick up the suture; (C) the suture is pulled out and tied over a bolus or a button fixing the graft in its bed.
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The surgical technique is based upon that of Kleinert. The method consists of six well defined stages-extension of the wound, opening of the sheath, apposition of the tendon ends, suturing of the tendon, closure of the wound, post-operative care. An atraumatic technique with magnification and avoidance of tension are essential. The skin wound is extended proximally for lesions which occur in extension and distally for those which occur in flexion and the wound is elongated at its extremities along the lateral aspects of the digit, thus avoiding acute angles for skin flaps. It is preferable to open the membranous portion of the digital sheath and to avoid dividing pulleys. Finger flexion exposes the distal cut end. The proximal end is more difficult to expose and may require 'milking' the palm with the wrist flexed, or the passage of a soft catheter to locate the site of the counter-incision. Irregular tendon ends are resected, but not by more than 5mm. One half of the grasping tendon suture can be placed at this time and inserted into the catheter which serves as a guide (Fig. 4). A straight needle transfixing both tendon and sheath relieves tension during repair. 'Grasping' sutures are now replacing the Bunnell criss-cross suture as they are more solid and result in less tendon devascularisation as they are placed in the palmar aspect of the tendon, thus avoiding the dorsal intratendinous vessels. A strong 3/0 or 4/0 synthetic suture is used. The addition of a fine 6/0 peripheral running suture 7 produces a smooth junction, the posterior half of which is performed by inverting the tendon (Fig. 5). If the site of tendon division is in one of the avascular segments then the dorsal aspect of the running suture should be omitted.
Specific indications When both tendons are divided both should be repaired so as to reduce adhesions, maintain vascularity, ensure independent flexion of each phalanx, provide greater grip strength and reduce the risk of PIP joint hyperextension. If the extent of damage to the two tendons is unequal, then FDS should be excised and F D P repaired. If only FDS is divided repair is debatable, but we agree with Kleinert 7 that a repaired FDS is preferable. If FDS repair is ignored the M P joint and PIP joint should be splinted flexed for 3 weeks to avoid producing a swan-neck deformity. If only F D P is divided primary suture should be undertaken, but only under excellent conditions, otherwise FDS mobility may be jeopardised. The sheath should be closed to avoid adhesions, but not with undue tightness, lest the price of restricting tendon excursion is paid. It is better not to fully advance the flaps at closure (Fig. 6). Post-operatively a dorsal splint immobilises the wrist in 40 ° of flexion and maintains the MP joint in 70 ° of flexion. Strickland has clearly showq, in a personal series of 50 cases, that early passive motion leads to improved results 1° producing more than 70% excellent, good, or fair results, against a 60% rate of poor results, or tendon rupture with more than 3 weeks immobilisation. The controlled semi-active motion programme of Young and Harman 11, popularised by Kleinert 7, allows passive flexion and active extension of the fingers. An elastic band connects the finger nail to the anterior forearm dressing. An intact extensor apparatus is necessary for this programme and thus it is contraindicated following replantation. The fingers should be directed towards the scaphoid tubercle (Fig. 7). Others favour individual passive flexion of the middle and distal phalanges 12 or early active mobilisation. In any event the surgeon should carefully monitor this postoperatively and if the laceration has occurred in an avascular portion of the tendon, total immobilisation in flexion for up to 6 weeks is probably advisable.
Secondary procedures. When conditions are not suit-
Fig. 4. The passage of the retracted proximal end of the FDP, through Camper's chiasrna of the FD$, is facilitated by the prior placement of a smal catheter. The catheter must be placed from distal to proximal in order to find its way through the division of the superficial tendon. The tendon may then be drawn distally.
able for primary suturing, treatment is restricted to wound excision and closure with the wrist and fingers immobilised in flexion. Subsequent treatment will be in the nature of either an early secondary suture or a secondary graft, either one-stage or two-stage. A tendon graft is used when primary or secondary suture has not been attempted. Exploration 3 months after tendon suture is indicated if active movement is minimal and this may be due to either adhesion formation or a broken suture, in which case either tenolysis or tendon graft would be required. Tenolysis is particularly indicated if the continuity of the tendon has been restablished, there is a good range of passive motion of the joints involved, the soft tissues are supple and the patient is well-motivated. If a fixed flexion deformity exists then a two-stage tendon graft may be undertaken.
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Fig. ,5 Suture of the two flexor tendons. The tendons should be sutured at two different levels when possible. At the level of the proximal phalanx the FDS is sutured first. A figure-of-eight suture is used to repair the distal flat portion of the superficialis tendon. A modified Mason-Kessler grasping suture is used for the profundus and completed with a peripheral running suture to provide a smooth anastomosis. The posterior half of the running suture is placed before the grasping suture as it is often difficult to turn the tendon over within the confines of the sheath. The anterior running suture is placed last. If the vascularity of the tendon is precarious the posterior running suture is omitted as its placement risks further devascularizing the tendon.
Flexor tendon grafting This technique 13 has become less frequently used since the advent of primary repair in 'no man's land'. A wide digito-palmar approach is required. The degree of adhesion formation dictates the extent of pulley preservation and priority is given to the A2 and A4 pulleys. The adherent tendons are removed with preservation of the distal portion of FDS to counter hyperextension and promote adhesions to the graft. Marked stiffness of MP or PIP joint is a contraindication to one-stage grafting. Choice of motor is important and while the F D P tendon has a long excursion and receives a lumbrical, the FDS has the advantage of independent muscle bellies and so enjoys a greater freedom of movement. Each potential motor is tested by pulling on its tendon and the one with the longest excursion is chosen. For the little finger the profundus is better. There are four commonly used grafts. Palmaris longus, whose presence is tested by active palm cupping and which is accessible in the same operative field, is long enough to extend from finger tip to proximal palm. The plantaris tendon, whose presence cannot be ascertained pre-operatively, can provide a longer graft and is exposed by an
incision over the medial border of the Achilles tendon. FDS is somewhat bulky, but useful in multiple finger lacerations. A toe extensor is the tendon of choice to replace a silicone implant. The distal end of the graft is fixed first and the tension regulated at the proximal end. Distal fixation is performed as for F D P advancement. For proximal graft fixation the excursion of the motor is first determined by pulling on its tendon with a traction suture and the tendon is then immobilised half way through its range by a needle which transfixes the skin and motor tendon with the wrist in the neutral position. The length of the graft is then adjusted so that the finger is flexed 15° more than its normal position of function with the ulnar fingers being relatively more flexed. The graft is then provisionally sutured in position. When the transfixion needle is removed, and with the wrist in about 40 ° of flexion, it should be possible to fully extend the grafted finger. Full wrist extension should carry the pulp of the grafted finger to within 3-4 cm of the palm. Proximal fixation should lie outside Zone II (the digital tunnel) and there are two favourable sites, the proximal palm
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Fig. 6 Closure of the sheath. The flaps elevated during exposure are not fully advanced on closure. The triangular gaps left at each extremity of the opening in the sheath allow a progressive enlargement of the sheath and facilitate the passage of the tendon.
and the wrist. If graft caliber is similar to motor tendon caliber then an end-to-end anastomosis is used but, more commonly, the graft is smaller than the motor and the interlacing technique of Pulvertaft should be used 9 (Fig. 8).
Fig. 7 Early semi-passive mobilization of the tendon. The index finger may be mobilised on its own. If one of the ulnar three fingers is repaired we prefer to place elastic traction on all 3 fingers. A pulley for the elastic is placed in the palm so as to allow complete flexion of the finger and direct it towards the scaphoid tubercle,
The precarious nutrition of one-stage grafts dictates cautious mobilisation. After 10 days of complete immobilisation the wrist and MPjoints are maintained flexed while the IP joints of the digit are passively mobilised. The splint is removed after 4 weeks but the distal pull-out suture should remain for a further week to minimise the likelihood of suture rupture. There then follows a careful rehabilitation in the following order--passive flexion, active flexion, active extension, passive extension, flexion against resistance. Two-stage grafting is effectively a three-stage procedure. Pre-operative rehabilitation ensures maximum passive mobility. The tendon sheath is then reconstructed and a silicone rod inserted, (Fig. 9). After 2 6 months a graft is placed in the pseudo-sheath formed around the implant. The flexor tendon is exposed as before and all undamaged pulleys are preserved along with a generous stump of the F D P tendon. If contracture persists following release of skin and scarred tendon, then a capsulolysis may be required. If the tendon 'bowstrings' by more than 2-3 mm at the level of the A2 and A4 pulleys then pulley reconstruction is indicated, using tendon graft or extensor retinaculum 13, (Fig. 10). The graft material is wrapped
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Fig. 8 Proximal fixation. The technique of Pulvertaft is able to compensate for differences between the graft size and size of the motor tendon. The tendon is pierced by a sharp, pointed tendon forcep in 2 or more perpendicular planes. The graft is pulled through the tendon and fixed with fine sutures. The end of the tendon is then bi-valved to surround the graft and create a smooth junction. Fig. 10 Pulley reconstruction. The pulleys are reconstructed using a tendon graft. At the base of the proximal phalanx the tendon is passed through the bone, woven through the remnants of the flexor sheath several times and then fixed through the bone again. The distal end of the graft is only inserted through a perforation in one cortex so as to not weaken the bone. If a wide strip of tendon is used it must be passed around the phalanx and sutured to itself.
Fig. 9 Placement of the implant during the first operative stage. The implant is fixed distally with a screw or sutured to the profundus stump. The proximal end is placed through the carpal tunnel into the forearm so that it may glide easily.
several times around the remnants of the sheath and the implant-sizer. Pulley tension is adjusted and the other end is fixed through a narrow fenestration in the bone. Final tension is adjusted, while the digit is flexed, with the help of mattress sutures between the pulley graft and the remants of the sheath. This method of fixation is firm and allows early mobilisation. For the middle phalanx pulley reconstruction is best achieved using one of the FDS bands, but if unsuitable, a circular graft surrounding the phalanx and sutured to itself can be used. 14 Implant size and length are then chosen so that it will extend from the tip of the finger to 5cm above the wrist and pass easily under the pulleys. Because it is highly electrostatic it should be kept moist throughout. It is fixed first to the distal phalanx with a screw or sutured to the profundus stump. It is next passed below the carpal ligament and when traction is applied
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the extent of finger excursion is recorded. The implant is then placed between FDS and F D P so that it may glide without kinking. The wound is closed and the hand is splinted with the wrist in 30 ° of flexion, M P joint in 60 ° of flexion, and IP joints in slight flexion. The splint is maintained for 3 weeks, after which graduated activity is increased until as complete a passive range of movement, up to 203 months, has been achieved. During the second operative stage the tendon graft is inserted into the pseudo-sheath and only a distal and small volar incision need be re-opened. The distal fixation of the implant is divided, the graft sutured to the end of the implant which is removed proximally, thus pulling the graft into its new bed (Fig. 11). Distal attachment, tension adjustment and proximal fixation are all carried out in the same manner as onestage grafting. Early passive mobilisation with elastic traction is instituted after the 4th day.
Complications of flexor tendon grafting The prognosis is worsened by any associated nerve, bone, or joint injury, or previous unsuccessful tendon surgery. The most important factor is the pre-operative state of the digit a6. Other common causes of failure are adhesions, suture separation, errors of fixation, bowstringing, swan-neck deformity, and lumbrical plus deformity. Following silicone implantation frank infection is rare, but a sterile synovitis, producing local pain and swelling, is not uncommon. Rest by splintage favours resolution.
Future prospects By fixation of both ends of a tendon implant, i.e. a true tendon prosthesis, even though this must be replaced eventually by a tendon graft, it does permit continued function of the motor muscle. Composite tendon and sheath allografts ~7 are still in the experimental stage, as are free vascularised tendon grafts.
Pedicle tendon grafts. Two-staged pedicle grafting has been recommended for lacerations of both tendons in the digital sheath in adults ~s. The FDS and F D P tendons are divided at the level of the lumbrical and the proximal stumps sutured together. A month later, FDS is divided near the fleshy belly in the forearm, passed under the pulleys and fixed to the distal phalanx. This technique is recommended when primary suture is contraindicated.
Flexor tendon lesions in the proximal zone (Zone I I I ) In this less complicated area primary or early secondary repair is possible, the latter being required only when there is the presence of initial sepsis. Because of their close proximity nerves are also commonly divided and should be repaired, along with the tendons. The carpal ligament should be divided. Post-operatively the wrist is immobilised, virtually straight, with the MP joints fully flexed to prevent anterior 'bowstringing' in the absence of a flexor retinaculum. Grafting is reserved for the rare case with fixed retraction, or loss of tendon substance.
Injuries to the flexor pollicis longus (FPL)
Fig. 11 Placement of the graft during the second operative stage. The tendon graft is sutured to the end of the implant and pulled into the pseudo-sheath.
Because F P L is solitary and acts over only two phalanges injury and repair has a better prognosis ~8. In Zone I, primary repair by tendon reinsertion is possible if the division is within 1.5 cm of the tendon insertion and because F P L has an independent muscle belly and no lumbrical it can be advanced further than a digital flexor. For lacerations in the distal portion of Zone II, F P L can be lengthened at the musculotendonous junction by up to 3cm allowing tendon reinsertion (Fig. 12). For more proximal lesions in Zone II primary repair should be performed. There are two important pulleys, one opposite the MP joint and the oblique pulley opposite the proximal phalanx and, while these should be preserved, the site of anastomosis should be kept away from the pulley by partial pulley resection and by joint flexion. The indications and technique of F P L grafting are similar to that described for the fingers. When the proximal stump is located within the thenar eminence the graft may be short but, if not, fixation at the level of the wrist is preferable. In Zone III, primary repair should be performed and it is important to avoid damaging the many nerve branches
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References
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Fig. 12 Technique of lengthening the flexor pollicis Iongus tendon. The tendon is divided obliquely at the level of the musculo-tendinous junction allowing lengthening of the tendon of up to 2.5 to 3 cm.
in this area. If a graft is required palmaris longus should be used. While arthrodesis of the IP joint provides good palliation by way of a stable thumb-finger grip, there is loss of precision pinch and adduction power. An important complication of FPL repair surgery is thumb malposition with the MP joint flexed, along with lack of flexion at the IPjoint. This can be improved by stabilisation of the MP joint in extension allowing recovery of IP joint flexion.
Address for Reprints: Professeur Raoul Tubiana, MD, Institut Francais de la Main, Centre Chirurgical Franklin, 15, rue Franklin, 75016 PARIS, France.
1. McGrouther D A, Ahmed M R (1981) Flextor tendon excursion in 'no man's land,. Hand 12, 129-141 2. Lundborg G, Myrhage R, Rydevik B (1977) The vaseularisation of human flexor tendons within the digital synovial sheath region--Structure and functional aspects. Journal of Hand Surgery 2, 6, 417-427 3. Manske P R, Lesker P A, Bridwell K et al., (1978) Nutrient pathways to flexor tendons within the fexor sheath. Journal of Hand Surgery 3, 287 4. Weber E R (/979) Synovial fluid nutrition of flexor tendons. Transactions of the Orthopaedic Research Society 4, 227 5. Potenza A A (1979) The healing process in wounds of the digital flexor tendons and tendon grafts: an experimental study. In: C Verdan, ed.: Tendon Surgery of the Hand. pp. 40-54, G.E.M.'s Monographs, Churchill Livingstone, Edinburgh 6. Matthews P, Richards H (1975) The repair reaction of flexor tendon within the digital sheath. Hand 7, 1, 27-29 7. Kleinert H E, Kutz J E, Ashbell T Set al., (1967) Primary repair of lacerated flexor tendons in 'no man's land'. Journal of Bone Joint Surgery 49, 577 8. Verdan C (1972) Half a century of flexor tendon repair: current status and changing philosophies. Journal Bone and Joint Surgery 54, 471-491 9. Pulvertaft R G (1971) Tendons grafts for tendon injuries in the fingers and thumb: a study of technique and results. Journal of Bone and Joint Surgery (Br.), 38, 175-194 10. Strickland J W, Glogovac S V (1980) Digital function following flexor tendon repair in zone II: a comparison of immobilisation and controlled passive motion techniques. Journal of Hand Surgery 5, 6, 537-543 ll. Young R E S, Harman J M (1960) Repair of tendon injuries of the hand. Annals of Surgery 151, 562 12. Duran R, Houser R G (1975) Controlled passive motion following flexor tendon repair in zones 2 and 3. In: AAOS Symposium on Tendon Surgery in the Hand, pp. 105-114, C. V. Mosby co, St Louis 13. Tubiana R (1960) Greffe des tendons fl~chisseurs des doigts et du pouce. Technique et r~sultats. Revue de Chirurgie Othopedique et Reparatrice de L'Appareil Moteur 46, 191 14. Lister G D (1983) Incision and closure of the flexor sheath during primary tendon repair. Hand, 5, 123 15. Paneva-Holevich E (1969) Two-stage tenoplasty in injury of the flexor tendon of the hand. Journal of Bone and Joint Surgery 51A, 1, 21-32 16. Boyes J H, Stark H (1971) Flexor tendon grafts in the fingers and thumb: a study of factors influencing results in 1000 cases. Journal of Bone Surgery 53, 1332-1342 17. Peacock E E, Madden J W (1967) Human composite tissue tendon allografts. Annals of Surgery 166, 624 18. Tubiana R (1986) The Hand, Vol 3, W B Saunders, Philadelphia
All the illustrations have been taken from R. Tubiana,
The Hand, Vol. 3, with the kind permission of the publishers, Masson (Paris) and W. B. Saunders (Philadelphia), 1986.
R. Tubiana, J. Beveridge
Flexor tendon injuries cause a particularly disabling compromise of prehensile function. Repair requires a strong collagen 'callus' able to resist powerful muscle traction yet not obstruct gliding planes. Knowledge of tendon micro-anatomy and nutrition has undergone considerable recent change allowing new techniques of repair. Anatomy: Physiology: Pathology Flexor tendons are mostly intrasynovial facilitating gliding but making repair more difficult (Fig. 1). Other problems also prevail. The tendons are long, crossing many joints, and the amplitude of excursion of flexor digitorum profundus (FDP) at the wrist is up to 7cm. 10 9 6
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However over the proximal phalanx only 2cm of tendon movement is necessary for full flexionx. There is an intimate relationship between the tendons of FDP and flexor digitorum superficialis (FDS) and considerable force is exerted by their muscles. Vascularity is precarious, particularly within the digital sheath. Both tendons receive a segmental supply through vincula. There is a short vinculum for each tendon at the ends of the sheath and a long vinculum common to both tendons at proximal interphalangeal (PIP) joint level. Thus the FDP tendon is devascularised by resection of FDS at this level. There are also avascular segments within the digital sheath, one either side of the long vinculum for the FDP tendon and proximal to the chiasma for the FDS tendon 2. These segments receive nutrition from synovial fluid pumped through micro-cannaliculi3'4. Tendon healing is also critical. The extrinsic theory that tendons healed by way of surrounding scar tissues led to prolonged immobilisation to allow these external adhesions to form 5. Tendons do however heal by an intrinsic tenoblastic response 6 and optimal function is achieved when the extrinsic scarring is minimised by way of careful repair of tendon and sheath, followed by immediate mobilisation. Although these tendons are traditionally described as crossing five topographical zones (distal segment, digital canal, palm and thenar eminence, carpal tunnel, wrist) 7'8 (Fig. 2) because of therapeutic similarities the
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Fig. 1 The flexor tendons and pulley system. At the level of the fingers the flexor digitorum superficialis (2) and flexor digitorum profundus (1), are surrounded by a synovial sheath and closely applied to the phalanx by the fibrous sheath. The thickened areas of the sheath correspond to the 5 annular (A1 to A5) and 3 cruciform (Cl to C3) pulleys. (3) Extensor digitorum communis (4) sagittal band (5) (6) (7) volar plates of the metacarpophalangeal (MP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints (8) insertion of the extensor digitorum communis at the base of the proximal phalanx (inconsistent) (9) insertion of the central extensor tendon (10) lateral extensor tendons (11 ) terminal insertion of the extensor tendon: on the base of the distal phalanx. R. Tubiana, MD, J. Beveridge, FRCS, Institut Francais de la Main, Paris
Current Orthopaedics(1986) 1, 91 99 © LongmanGroupUK Ltd.
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number can be reduced to three for practical purposes. Zone II, the intermediate zone, corresponds to the portion of the digital sheath which includes both tendons. Zone I, the distal zone, represents the course of the tendons distal to the intermediate zone, while Zone III, the proximal zone, includes the palmar, carpal and wrist regions. Clearly the intimate tendon relations and poor blood supply in Zone II make this the most problematical area.
Clinical features An incised wound is the commonest cause with tendon rupture being much less common and often in association with a frictional or inflammatory process. Terminal F D P avulsion (rugby players injury) is due to sudden DIP joint hyperextension. Partial division of a tendon is evidenced by a tendon sheath haematoma but preservation of active flexion. Complete division of an F D P tendon implies loss of active flexion of the distal phalanx when the middle phalanx is held rigidly. Complete division of the flexor pollicis longus (FPL) tendon implies loss of active flexion of the IP joint of the thumb. Complete division of an FDS tendon is not so easily recognised as an intact profundus can flex all joints. However by maintaining the other fingers passively extended the finger in
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Fig. 2 The topographical classification of the hand adopted by the International Federation of Societies for Surgery of the Hand. The anatomical regions crossed by only the flexor pollicis Iongus (FPL) are preceded by the letter T (thumb).
question will not flex actively at the PIP joint. According to the position of flexion of the digit when the incised wound occurred the tendon laceration may be some distance from the skin wound when the finger is extended.
Surgical treatment of flexor tendon injuries Partial division of flexor tendons. All suspected cases of flexor tendon injury should be explored. No repair is necessary if more than half the transverse diameter is intact, but a running epitenon suture may facilitate subsequent gliding. Smaller flaps should be excised to prevent catching. More than half diameter lacerations should be primarily repaired and mobilised early in the post-operative phase as after a complete laceration repair.
Complete division. The various treatment methods can be grouped into three categories--operations to restore flexor tendon function (advancement, suture, grafting, tenolysis), palliative operations (tenodesis, arthrodesis, tendon transfer, artificial tendon grafting), and amputation. Clearly the optimal procedure is restoration of flexor tendon function but other procedures do have their indications which depend on several factors of which timing of the tendon repair, the presence of associated lesions, the patient's general condition and requirements, the site of the lesion and the surgical facilities are the more important. Timing of repair. The time interval between trauma and repair is important. Primary repair (within 24 h) is performed if the wound is likely to heal by first intention. This implies within 6h of injury (the so called 'golden period') or during the next 18 h if the wound is tidy, has been cleaned, dressed and splinted and the patient put on antibiotics. For those wounds not fulfilling the primary repair criteria secondary repair is carried out within 3 5 weeks provided the wound is clean and soft tissue coverage adequate. Late repair (after 5 weeks) is necessary for the most serious wounds and, because of tendon retraction, the choice lies between graft or palliation. Associated lesions. With a clean wound of both skin and tendon, repair is indicated up to 5 weeks and thereafter a one-staged tendon graft may be performed. For a clean wound, but with associated neurovascular division, primary repair of nerve and tendon is indicated in the first 24h and if both arteries have been divided at least one should be repaired. In the intermediate period (up to 5 weeks) nerve and tendons should be repaired, but at this stage the vessels are irreparable. In the late phase (after 5 weeks) grafting of both nerve and tendon is required. Associated bone or joint injury, if stable, does not alter the above management, but, if unstable or comminuted, the skeleton should be treated primarily and the tendons secondarily. If presentation of such a complex injury
CURRENT ORTHOPAEDICS 93 occurs beyond the first 24h then a silicone rod delayed tendon graft or pedicle graft is necessary. With significant local bone and soft tissue damage treatment is directed to the wound and the tendon is dealt with secondarily. The most severe categories of these may be candidates for primary amputation. If presentation after bone and soft tissue damage is late then local scarring precludes anything more than arthrodesis or even amputation. Status of the patient. Age is an important factor, with younger patients faring better. Lack of co-operation in the under 6-year-old precludes grafting as a method of management 9. In addition the psychological and occupational status of the patient is important along with surgical facilities and experience.
FDP lesions in the distal zone (Zone I) Site of the lesion. At this level only F D P is present and can be either divided or avulsed. If avulsed without a bone fragment the tendon end is sutured directly to bone with the same technique as for a tendon graft. When a fragment of bone is avulsed, the fragment should be replaced using oblique K-wires with the DIP joint in 15 ° of flexion. If the tendon has not retracted past the PIP joint then the vinculum longus will still be intact and thus reinsertion is possible even after several weeks, particularly in young patients. If retraction into the palm has occurred a tendon graft or palliative procedure will be required. If F D P has been divided, but within lcm of its insertion, reinsertion is possible particularly in the young. Undue tension may cause a flexion deformity of the D I P joint or restricted flexion of adjacent F D P tendons. The A4 pulley should be repaired. The tendon end is fixed to bone by a pull-out suture through the split tendon stump, distal phalanx and nail tied over a button (Fig. 3). Wrist, M P joint and PIP joint are maintained at 40 °, 70 °, and 35 ° of flexion respectively. The D I P joint is held in extension with a small splint and passive movement of this joint is started within a few days.
The splint and pull-out sutures are removed after 4 weeks. If the site of division is more than lcm from the tendon insertion primary end to end repair should be performed, although the results are less satisfactory if there is retraction into the palm as the vinculum longus will have been torn. While loss of F D P function with an intact FDS produces only a minimal deficit there is a more substantial loss of power and, in the presence of infection or a crush injury, secondary suture or grafting may be performed depending upon the patient's occupation. Under no circumstances should an intact FDS be sacrificed in order to repair FDP. If repair of F D P is not indicated and P I P joint movement is good then the D I P joint should be stabilised, either by tenodesis to the A4 pulley or the shaft of the middle phalanx, or by capsulodesis if the site of division is too distal. The D I P joint should be stabilised in about 20 ° of flexion and held for 5 weeks by a K-wire. These procedures allow passive DIP joint flexion and thus are preferred to arthrodesis. F D P tenolysis may be necessary if pain in the palm persists, or if active FDS IP joint movement is unsatisfactory. When F D P has not been repaired a lumbrical plus deformity caused by proximal retraction of the lumbricals may occur.
Flexor tendon lesions in the intermediate zone (Zone
II). While it has always been traditional not to recommend primary suture in 'no man's land' this is now the method of choice although failure may place the whole future of the hand at risk. Primary suture is particularly applicable to children and multiple F D P divisions. Certain criteria should be observed 4,v. The wound should be expected to heal by first intention, the associated lesions should be compatible with rapid mobilisation and surgical facilities should be excellent.
Fig. 3 Distal fixation of the graft. The distal end of the profundus tendon stump is divided in the midline; (A) a small gouge is used to raise a flap of bone under the tendon; (B) a hole is then drilled through the bone so that it exits through the nail, distal to the lunula. A needle is then passed, blunt end first through this hole, to pick up the suture; (C) the suture is pulled out and tied over a bolus or a button fixing the graft in its bed.
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FLEXOR TENDON INJURIES OF THE HAND
The surgical technique is based upon that of Kleinert. The method consists of six well defined stages-extension of the wound, opening of the sheath, apposition of the tendon ends, suturing of the tendon, closure of the wound, post-operative care. An atraumatic technique with magnification and avoidance of tension are essential. The skin wound is extended proximally for lesions which occur in extension and distally for those which occur in flexion and the wound is elongated at its extremities along the lateral aspects of the digit, thus avoiding acute angles for skin flaps. It is preferable to open the membranous portion of the digital sheath and to avoid dividing pulleys. Finger flexion exposes the distal cut end. The proximal end is more difficult to expose and may require 'milking' the palm with the wrist flexed, or the passage of a soft catheter to locate the site of the counter-incision. Irregular tendon ends are resected, but not by more than 5mm. One half of the grasping tendon suture can be placed at this time and inserted into the catheter which serves as a guide (Fig. 4). A straight needle transfixing both tendon and sheath relieves tension during repair. 'Grasping' sutures are now replacing the Bunnell criss-cross suture as they are more solid and result in less tendon devascularisation as they are placed in the palmar aspect of the tendon, thus avoiding the dorsal intratendinous vessels. A strong 3/0 or 4/0 synthetic suture is used. The addition of a fine 6/0 peripheral running suture 7 produces a smooth junction, the posterior half of which is performed by inverting the tendon (Fig. 5). If the site of tendon division is in one of the avascular segments then the dorsal aspect of the running suture should be omitted.
Specific indications When both tendons are divided both should be repaired so as to reduce adhesions, maintain vascularity, ensure independent flexion of each phalanx, provide greater grip strength and reduce the risk of PIP joint hyperextension. If the extent of damage to the two tendons is unequal, then FDS should be excised and F D P repaired. If only FDS is divided repair is debatable, but we agree with Kleinert 7 that a repaired FDS is preferable. If FDS repair is ignored the M P joint and PIP joint should be splinted flexed for 3 weeks to avoid producing a swan-neck deformity. If only F D P is divided primary suture should be undertaken, but only under excellent conditions, otherwise FDS mobility may be jeopardised. The sheath should be closed to avoid adhesions, but not with undue tightness, lest the price of restricting tendon excursion is paid. It is better not to fully advance the flaps at closure (Fig. 6). Post-operatively a dorsal splint immobilises the wrist in 40 ° of flexion and maintains the MP joint in 70 ° of flexion. Strickland has clearly showq, in a personal series of 50 cases, that early passive motion leads to improved results 1° producing more than 70% excellent, good, or fair results, against a 60% rate of poor results, or tendon rupture with more than 3 weeks immobilisation. The controlled semi-active motion programme of Young and Harman 11, popularised by Kleinert 7, allows passive flexion and active extension of the fingers. An elastic band connects the finger nail to the anterior forearm dressing. An intact extensor apparatus is necessary for this programme and thus it is contraindicated following replantation. The fingers should be directed towards the scaphoid tubercle (Fig. 7). Others favour individual passive flexion of the middle and distal phalanges 12 or early active mobilisation. In any event the surgeon should carefully monitor this postoperatively and if the laceration has occurred in an avascular portion of the tendon, total immobilisation in flexion for up to 6 weeks is probably advisable.
Secondary procedures. When conditions are not suit-
Fig. 4. The passage of the retracted proximal end of the FDP, through Camper's chiasrna of the FD$, is facilitated by the prior placement of a smal catheter. The catheter must be placed from distal to proximal in order to find its way through the division of the superficial tendon. The tendon may then be drawn distally.
able for primary suturing, treatment is restricted to wound excision and closure with the wrist and fingers immobilised in flexion. Subsequent treatment will be in the nature of either an early secondary suture or a secondary graft, either one-stage or two-stage. A tendon graft is used when primary or secondary suture has not been attempted. Exploration 3 months after tendon suture is indicated if active movement is minimal and this may be due to either adhesion formation or a broken suture, in which case either tenolysis or tendon graft would be required. Tenolysis is particularly indicated if the continuity of the tendon has been restablished, there is a good range of passive motion of the joints involved, the soft tissues are supple and the patient is well-motivated. If a fixed flexion deformity exists then a two-stage tendon graft may be undertaken.
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Fig. ,5 Suture of the two flexor tendons. The tendons should be sutured at two different levels when possible. At the level of the proximal phalanx the FDS is sutured first. A figure-of-eight suture is used to repair the distal flat portion of the superficialis tendon. A modified Mason-Kessler grasping suture is used for the profundus and completed with a peripheral running suture to provide a smooth anastomosis. The posterior half of the running suture is placed before the grasping suture as it is often difficult to turn the tendon over within the confines of the sheath. The anterior running suture is placed last. If the vascularity of the tendon is precarious the posterior running suture is omitted as its placement risks further devascularizing the tendon.
Flexor tendon grafting This technique 13 has become less frequently used since the advent of primary repair in 'no man's land'. A wide digito-palmar approach is required. The degree of adhesion formation dictates the extent of pulley preservation and priority is given to the A2 and A4 pulleys. The adherent tendons are removed with preservation of the distal portion of FDS to counter hyperextension and promote adhesions to the graft. Marked stiffness of MP or PIP joint is a contraindication to one-stage grafting. Choice of motor is important and while the F D P tendon has a long excursion and receives a lumbrical, the FDS has the advantage of independent muscle bellies and so enjoys a greater freedom of movement. Each potential motor is tested by pulling on its tendon and the one with the longest excursion is chosen. For the little finger the profundus is better. There are four commonly used grafts. Palmaris longus, whose presence is tested by active palm cupping and which is accessible in the same operative field, is long enough to extend from finger tip to proximal palm. The plantaris tendon, whose presence cannot be ascertained pre-operatively, can provide a longer graft and is exposed by an
incision over the medial border of the Achilles tendon. FDS is somewhat bulky, but useful in multiple finger lacerations. A toe extensor is the tendon of choice to replace a silicone implant. The distal end of the graft is fixed first and the tension regulated at the proximal end. Distal fixation is performed as for F D P advancement. For proximal graft fixation the excursion of the motor is first determined by pulling on its tendon with a traction suture and the tendon is then immobilised half way through its range by a needle which transfixes the skin and motor tendon with the wrist in the neutral position. The length of the graft is then adjusted so that the finger is flexed 15° more than its normal position of function with the ulnar fingers being relatively more flexed. The graft is then provisionally sutured in position. When the transfixion needle is removed, and with the wrist in about 40 ° of flexion, it should be possible to fully extend the grafted finger. Full wrist extension should carry the pulp of the grafted finger to within 3-4 cm of the palm. Proximal fixation should lie outside Zone II (the digital tunnel) and there are two favourable sites, the proximal palm
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FLEXOR T E N D O N I N J U R I E S OF THE H A N D
Fig. 6 Closure of the sheath. The flaps elevated during exposure are not fully advanced on closure. The triangular gaps left at each extremity of the opening in the sheath allow a progressive enlargement of the sheath and facilitate the passage of the tendon.
and the wrist. If graft caliber is similar to motor tendon caliber then an end-to-end anastomosis is used but, more commonly, the graft is smaller than the motor and the interlacing technique of Pulvertaft should be used 9 (Fig. 8).
Fig. 7 Early semi-passive mobilization of the tendon. The index finger may be mobilised on its own. If one of the ulnar three fingers is repaired we prefer to place elastic traction on all 3 fingers. A pulley for the elastic is placed in the palm so as to allow complete flexion of the finger and direct it towards the scaphoid tubercle,
The precarious nutrition of one-stage grafts dictates cautious mobilisation. After 10 days of complete immobilisation the wrist and MPjoints are maintained flexed while the IP joints of the digit are passively mobilised. The splint is removed after 4 weeks but the distal pull-out suture should remain for a further week to minimise the likelihood of suture rupture. There then follows a careful rehabilitation in the following order--passive flexion, active flexion, active extension, passive extension, flexion against resistance. Two-stage grafting is effectively a three-stage procedure. Pre-operative rehabilitation ensures maximum passive mobility. The tendon sheath is then reconstructed and a silicone rod inserted, (Fig. 9). After 2 6 months a graft is placed in the pseudo-sheath formed around the implant. The flexor tendon is exposed as before and all undamaged pulleys are preserved along with a generous stump of the F D P tendon. If contracture persists following release of skin and scarred tendon, then a capsulolysis may be required. If the tendon 'bowstrings' by more than 2-3 mm at the level of the A2 and A4 pulleys then pulley reconstruction is indicated, using tendon graft or extensor retinaculum 13, (Fig. 10). The graft material is wrapped
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Fig. 8 Proximal fixation. The technique of Pulvertaft is able to compensate for differences between the graft size and size of the motor tendon. The tendon is pierced by a sharp, pointed tendon forcep in 2 or more perpendicular planes. The graft is pulled through the tendon and fixed with fine sutures. The end of the tendon is then bi-valved to surround the graft and create a smooth junction. Fig. 10 Pulley reconstruction. The pulleys are reconstructed using a tendon graft. At the base of the proximal phalanx the tendon is passed through the bone, woven through the remnants of the flexor sheath several times and then fixed through the bone again. The distal end of the graft is only inserted through a perforation in one cortex so as to not weaken the bone. If a wide strip of tendon is used it must be passed around the phalanx and sutured to itself.
Fig. 9 Placement of the implant during the first operative stage. The implant is fixed distally with a screw or sutured to the profundus stump. The proximal end is placed through the carpal tunnel into the forearm so that it may glide easily.
several times around the remnants of the sheath and the implant-sizer. Pulley tension is adjusted and the other end is fixed through a narrow fenestration in the bone. Final tension is adjusted, while the digit is flexed, with the help of mattress sutures between the pulley graft and the remants of the sheath. This method of fixation is firm and allows early mobilisation. For the middle phalanx pulley reconstruction is best achieved using one of the FDS bands, but if unsuitable, a circular graft surrounding the phalanx and sutured to itself can be used. 14 Implant size and length are then chosen so that it will extend from the tip of the finger to 5cm above the wrist and pass easily under the pulleys. Because it is highly electrostatic it should be kept moist throughout. It is fixed first to the distal phalanx with a screw or sutured to the profundus stump. It is next passed below the carpal ligament and when traction is applied
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FLEXOR T E N D O N I N J U R I E S O F THE H A N D
the extent of finger excursion is recorded. The implant is then placed between FDS and F D P so that it may glide without kinking. The wound is closed and the hand is splinted with the wrist in 30 ° of flexion, M P joint in 60 ° of flexion, and IP joints in slight flexion. The splint is maintained for 3 weeks, after which graduated activity is increased until as complete a passive range of movement, up to 203 months, has been achieved. During the second operative stage the tendon graft is inserted into the pseudo-sheath and only a distal and small volar incision need be re-opened. The distal fixation of the implant is divided, the graft sutured to the end of the implant which is removed proximally, thus pulling the graft into its new bed (Fig. 11). Distal attachment, tension adjustment and proximal fixation are all carried out in the same manner as onestage grafting. Early passive mobilisation with elastic traction is instituted after the 4th day.
Complications of flexor tendon grafting The prognosis is worsened by any associated nerve, bone, or joint injury, or previous unsuccessful tendon surgery. The most important factor is the pre-operative state of the digit a6. Other common causes of failure are adhesions, suture separation, errors of fixation, bowstringing, swan-neck deformity, and lumbrical plus deformity. Following silicone implantation frank infection is rare, but a sterile synovitis, producing local pain and swelling, is not uncommon. Rest by splintage favours resolution.
Future prospects By fixation of both ends of a tendon implant, i.e. a true tendon prosthesis, even though this must be replaced eventually by a tendon graft, it does permit continued function of the motor muscle. Composite tendon and sheath allografts ~7 are still in the experimental stage, as are free vascularised tendon grafts.
Pedicle tendon grafts. Two-staged pedicle grafting has been recommended for lacerations of both tendons in the digital sheath in adults ~s. The FDS and F D P tendons are divided at the level of the lumbrical and the proximal stumps sutured together. A month later, FDS is divided near the fleshy belly in the forearm, passed under the pulleys and fixed to the distal phalanx. This technique is recommended when primary suture is contraindicated.
Flexor tendon lesions in the proximal zone (Zone I I I ) In this less complicated area primary or early secondary repair is possible, the latter being required only when there is the presence of initial sepsis. Because of their close proximity nerves are also commonly divided and should be repaired, along with the tendons. The carpal ligament should be divided. Post-operatively the wrist is immobilised, virtually straight, with the MP joints fully flexed to prevent anterior 'bowstringing' in the absence of a flexor retinaculum. Grafting is reserved for the rare case with fixed retraction, or loss of tendon substance.
Injuries to the flexor pollicis longus (FPL)
Fig. 11 Placement of the graft during the second operative stage. The tendon graft is sutured to the end of the implant and pulled into the pseudo-sheath.
Because F P L is solitary and acts over only two phalanges injury and repair has a better prognosis ~8. In Zone I, primary repair by tendon reinsertion is possible if the division is within 1.5 cm of the tendon insertion and because F P L has an independent muscle belly and no lumbrical it can be advanced further than a digital flexor. For lacerations in the distal portion of Zone II, F P L can be lengthened at the musculotendonous junction by up to 3cm allowing tendon reinsertion (Fig. 12). For more proximal lesions in Zone II primary repair should be performed. There are two important pulleys, one opposite the MP joint and the oblique pulley opposite the proximal phalanx and, while these should be preserved, the site of anastomosis should be kept away from the pulley by partial pulley resection and by joint flexion. The indications and technique of F P L grafting are similar to that described for the fingers. When the proximal stump is located within the thenar eminence the graft may be short but, if not, fixation at the level of the wrist is preferable. In Zone III, primary repair should be performed and it is important to avoid damaging the many nerve branches
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References
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Fig. 12 Technique of lengthening the flexor pollicis Iongus tendon. The tendon is divided obliquely at the level of the musculo-tendinous junction allowing lengthening of the tendon of up to 2.5 to 3 cm.
in this area. If a graft is required palmaris longus should be used. While arthrodesis of the IP joint provides good palliation by way of a stable thumb-finger grip, there is loss of precision pinch and adduction power. An important complication of FPL repair surgery is thumb malposition with the MP joint flexed, along with lack of flexion at the IPjoint. This can be improved by stabilisation of the MP joint in extension allowing recovery of IP joint flexion.
Address for Reprints: Professeur Raoul Tubiana, MD, Institut Francais de la Main, Centre Chirurgical Franklin, 15, rue Franklin, 75016 PARIS, France.
1. McGrouther D A, Ahmed M R (1981) Flextor tendon excursion in 'no man's land,. Hand 12, 129-141 2. Lundborg G, Myrhage R, Rydevik B (1977) The vaseularisation of human flexor tendons within the digital synovial sheath region--Structure and functional aspects. Journal of Hand Surgery 2, 6, 417-427 3. Manske P R, Lesker P A, Bridwell K et al., (1978) Nutrient pathways to flexor tendons within the fexor sheath. Journal of Hand Surgery 3, 287 4. Weber E R (/979) Synovial fluid nutrition of flexor tendons. Transactions of the Orthopaedic Research Society 4, 227 5. Potenza A A (1979) The healing process in wounds of the digital flexor tendons and tendon grafts: an experimental study. In: C Verdan, ed.: Tendon Surgery of the Hand. pp. 40-54, G.E.M.'s Monographs, Churchill Livingstone, Edinburgh 6. Matthews P, Richards H (1975) The repair reaction of flexor tendon within the digital sheath. Hand 7, 1, 27-29 7. Kleinert H E, Kutz J E, Ashbell T Set al., (1967) Primary repair of lacerated flexor tendons in 'no man's land'. Journal of Bone Joint Surgery 49, 577 8. Verdan C (1972) Half a century of flexor tendon repair: current status and changing philosophies. Journal Bone and Joint Surgery 54, 471-491 9. Pulvertaft R G (1971) Tendons grafts for tendon injuries in the fingers and thumb: a study of technique and results. Journal of Bone and Joint Surgery (Br.), 38, 175-194 10. Strickland J W, Glogovac S V (1980) Digital function following flexor tendon repair in zone II: a comparison of immobilisation and controlled passive motion techniques. Journal of Hand Surgery 5, 6, 537-543 ll. Young R E S, Harman J M (1960) Repair of tendon injuries of the hand. Annals of Surgery 151, 562 12. Duran R, Houser R G (1975) Controlled passive motion following flexor tendon repair in zones 2 and 3. In: AAOS Symposium on Tendon Surgery in the Hand, pp. 105-114, C. V. Mosby co, St Louis 13. Tubiana R (1960) Greffe des tendons fl~chisseurs des doigts et du pouce. Technique et r~sultats. Revue de Chirurgie Othopedique et Reparatrice de L'Appareil Moteur 46, 191 14. Lister G D (1983) Incision and closure of the flexor sheath during primary tendon repair. Hand, 5, 123 15. Paneva-Holevich E (1969) Two-stage tenoplasty in injury of the flexor tendon of the hand. Journal of Bone and Joint Surgery 51A, 1, 21-32 16. Boyes J H, Stark H (1971) Flexor tendon grafts in the fingers and thumb: a study of factors influencing results in 1000 cases. Journal of Bone Surgery 53, 1332-1342 17. Peacock E E, Madden J W (1967) Human composite tissue tendon allografts. Annals of Surgery 166, 624 18. Tubiana R (1986) The Hand, Vol 3, W B Saunders, Philadelphia
All the illustrations have been taken from R. Tubiana,
The Hand, Vol. 3, with the kind permission of the publishers, Masson (Paris) and W. B. Saunders (Philadelphia), 1986.