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(vi) Flexor tendon injuries
MINI-SYMPOSIUM: THE HAND
(vi) Flexor tendon injuries
The goal of surgical repair has remained the same since Verdan and Kleinert’s early work that is: to achieve a primary tendon repair with sufficient tensile strength to allow the instigation of a post-operative rehabilitation regime which prevents adhesion formation and stimulates the restoration of gliding surfaces and repair site healing.4
P A G Torrie N Atwal D Sheriff A Cowey
Anatomy The flexor digitorum superficialis (FDS) originates from the volar surface of the humerus, ulna, and radius. In the midsection of the forearm, the FDS muscle belly divides into four distinct bundles, which separate into a superficial and a deep layer; the tendons in the superficial layer act upon the middle and ring fingers, and the deep layer tendons act upon the index and little fingers. The FDS tendon to the small finger may not be present in all individuals. The common muscle belly of the flexor digitorum profundus (FDP) originates from the anterior-medial aspect of the ulna and interosseous membrane and is dorsal to FDS in the volar aspect of the forearm. In the hand at the level of the A1 pulley the FDS tendon bifurcates, allowing the deeper FDP tendon to pass distally to its insertion at the base of the distal phalanx. The two limbs of the FDS tendon deviate from the midline, wrapping around profundus (known as Camper’s chiasm), before ultimately inserting dorsal to the profundus tendon on the volar surface of the proximal half of the middle phalanx. There is a predictable arrangement of five annular pulleys and three cruciform pulleys in the fingers, described initially by Doyle and Blythe and with the subsequent description by Hunter of a fifth annular pulley.5 The arrangement in the thumb includes two annular and an oblique pulley. The A1, A3, and A5 pulleys originate from the palmar plates of the MCP, PIP, and the DIP joints, respectively. The A2 and A4 pulleys are continuous with the periosteum of the proximal half of the proximal phalanx and of the middle third of the middle phalanx, respectively. The cruciform pulleys are located between the A2 and A3 pulleys (C1), between the A3 and A4 pulleys (C2), and between the A4 and A5 pulleys (C3) (Figure 1). The annular pulley arrangement provides tendon constraint with an optimal moment arm to maximize joint motion for a given amount of tendon excursion. Flexor tendon nutrition is received from both vascular (intrinsic) and synovial (extrinsic) sources. Three vascular (intrinsic) supplies are routinely described; the longitudinally
Abstract Flexor tendon injuries are a commonly occurring and often challenging injury presenting to hand specialists that require meticulous surgical repair and early post-operative mobilization in order to achieve a successful functional outcome. Historically the methods of repair and post-operative rehabilitation protocols varied greatly between surgeons, and were based largely on individual experience and anecdotal evidence. Over the last three decades, extensive documentation in the literature, including basic scientific research, randomized controlled trials and a Cochrane review has provided evidence detailing improved or beneficial surgical techniques and post-operative rehabilitation protocols, aimed at ultimately improving the patients’ final functional outcome, after a flexor tendon injury.
Keywords anatomy; biomechanics; flexor tendon injuries; outcomes; rehabilitation protocol; surgical repair
Introduction The incidence of flexor tendon injuries in the UK is over 3200 per annum. Achieving normal function post-repair remains a constant challenge to hand surgeons around the world. Pioneering work in the 1960s by Verdan1 and Kleinert2 showed that the primary flexor tendon repair could be successful. This contradicted the commonly held belief at the time that excision of the divided tendon and delayed grafting, as advocated by Bunnell half a century earlier,3 yielded the best results. Since the 1960s the surgical technique, the basic science and the rehabilitation of flexor tendon repair have been the subject of numerous scientific studies both in vivo and ex vivo. Yet, despite the vast volume of literature and the advances made in all aspects of repair, a widely accepted definitive management protocol, leading to predictable results, has yet to be established.
P A G Torrie MB ChB MRCS (eng) Orthopaedic Registrar at the Royal United Hospital Bath NHS Trust, Combe Park, Bath BA1 3NG, UK. N Atwal MB ChB BSc (hons) MRCS (eng) Orthopaedic Registrar at the Orthopaedic registrar. Royal United Hospital Bath NHS Trust, Combe Park, Bath BA1 3NG, UK. D Sheriff BSc MCSP Specialist Hand Physiotherapist at the Royal United Hospital Bath NHS Trust, Combe Park, Bath BA1 3NG, UK. A Cowey MB ChB FRCS (T þ O) Hand Dip Surg Consultant Hand Surgeon at the Royal United Hospital Bath NHS Trust, Combe Park, Bath BA1 3NG, UK.
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Figure 1 Picture of the arrangement of pulleys in the flexor sheath.
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The biomechanical properties in vivo of a flexor tendon directly correlate with the strength required in the surgical repair, necessary to allow optimal rehabilitation without early failure. During un-resisted passive flexion, flexor tendons are subjected to 2e4 N of force. Active flexion with mild and moderate resistances subjects the flexor tendon to 10 N and 17 N of force respectively, whilst a strong composite grasp loads the flexor tendons with 70 N of force and firm tip pinch with 120 N.8
oriented vessels on the tendon surface, the vincular arrangement derived from the paired digital vessels and vessels of intraosseous origin at the tendon insertions. Watershed areas of limited vascular supply within the tendon exist. There is a single avascular zone within the intrasynovial portion of the FDS tendon over the proximal phalanx and under the A2 pulley. There are two avascular zones within the intrasynovial portion of the FDP tendon; the first lies over the proximal phalanx deep to the A2 pulley, and the second is located over the middle phalanx, usually under the A4 pulley. Synovial (extrinsic) nutrition occurs through imbibition whereby fluid is forced into the interstices of the tendon through small ridges in the tendon surface as the digit is flexed and extended.6 The A2 and A4 pulleys are crucial for normal digital function as they prevent tendon bowstringing and provide optimal joint flexion for a given amount of tendon excursion. The flexor tendons are composed of collagen (primarily type I collagen e 78%) and non-collagenous proteins. The tendon fascicles consist of long, narrow, spiralling bundles of mature fibroblasts (tenocytes) and type 1 collagen fibres, each fascicle is covered by a thin visceral and parietal adventitia called the endotenon which separates it from the adjacent fascicle. A single tendon contains numerous fascicles that are grouped together and covered by another adventitial layer e the epitenon that has an associated fluid environment similar to synovial fluid.4 Verdan has classified flexor tendon injuries into five distinct zones of injury, which are routinely utilized by hand surgeons. The zone of injury has relevance in relation to the propensity for adhesion formation, maximally seen in Zones II and IV. Zone I is distal to the insertion of superficialis, just proximal of the distal interphalangeal joint, therefore affects the profundus only. Zone II is the region from the metacarpal head to the middle of the middle phalanx with the FDP and FDS within one flexor tendon sheath (FDP deep to FDS). Zone III is the region between the transverse carpal ligament and the proximal margin of the tendon sheath. Zone IV is deep the transverse carpal ligament, and Zone V is at the wrist, proximal to the transverse carpal ligament7 (Figure 2).
Surgical repair Prior to any surgical repair a full assessment of the injured hand should be made to identify any functional, neurovascular deficits as well as issues pertaining to skin coverage and the integrity of the underlying bony skeleton. This assessment should guide the surgeon as to which structures are potentially damaged and direct the informed consent and intended surgical pathway. In tendon divisions ultrasound may be useful in identifying the location of the proximal tendon end preoperatively as may the presence of palm tenderness on clinical examination. The timing of surgical repair is not clear and evidence is anecdotal, some have claimed it should be done as soon as possible post-injury, others within 72 h with more recent opinion suggesting a delay of 4e7 days is advisable, allowing the swelling to reduce.9 What is clear is the outcomes are improved if an appropriately trained surgeon undertakes the procedure even if it is several days’ post-injury as opposed to an inexperienced surgeon attempting repair immediately after division. The time frame beyond which primary repair is not recommended is equally unclear, delay beyond 7 days is unadvisable due to the potential risk of tendon ends becoming rounded and possibly adherent, sheath collapse and fibrosis as well as myotendinous retraction, all of which make the procedure technically more demanding. There is documented evidence of successful repair beyond a month10 but in cases beyond 7 days’ post-injury the operating surgeon must be prepared to encounter tendon ends that cannot be approximated and consider an alternative surgical strategy in these circumstances. Repair should be performed in an operating theatre with good lighting under general or regional anaesthetic with the use of a brachial tourniquet and preferably loupe magnification. The key to successful surgical outcomes in all procedures is meticulous tissue handling but this is never truer than in flexor tendon repairs. Poor tissue handling damages the tendon surfaces and surrounding structures and increases the risk of fibrosis and secondary adhesions. The surgical approach is either a mid lateral or Bruner incision where possible incorporating the original laceration. Thick skin flaps should be raised and the flexor sheath exposed ensuring the neurovascular bundles are identified and protected throughout. Once the sheath is exposed the distal end of the divided flexor tendon is usually easily identified and it is the proximal end that has commonly retracted. The proximal stump maybe delivered into the wound with gentle proximal to distal milking, once visible the stump maybe brought through the sheath carefully using fine-toothed forceps (avoid passing instruments blindly down the tendon sheath as it increase the risk of intrasynovial damage and secondary adhesions). If the proximal tendon stump cannot be milked into the wound it can be identified more proximal via a separate incision and an infant feeding tube passed from distal to proximal is then
Figure 2 Verdan’s flexor zones.
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MINI-SYMPOSIUM: THE HAND
sutured to the tendon proximally and tube pulled distally delivering the stump into the wound.11 Care must be taken to preserve the flexor sheath as much as possible during this component of the surgery; traditional teaching is to preserve the A2 and A4 pulleys at all costs in order to prevent tendon bowstringing and subsequent loss of finger joint movement. More recent work has suggested that if necessary release of the A2 or A4 pulleys in isolation is acceptable as placing a tendon repair beneath one of these strong unyielding pulleys may compromise tendon gliding and therefore surgical outcome.9 Once the tendon ends have been delivered into the wound attention should be focused on the repair. If the tendon laceration is in Zone 1 of the flexor sheath and within 1 cm of the FDP insertion into the distal phalanx, an end-to-end repair should not be attempted. Instead, a tendon to bone repair should be performed. If the laceration is greater than 1 cm from the FDP insertion in Zone 1 or in Zones 2e5 a direct end-to-end tendon repair should be undertaken. In cases where both FDP and FDS are divided an attempt should be made to repair both tendons as sacrificing the FDS limits the reconstructive options if the FDP repair fails. Considerable work has been done to try and identify the repair technique producing the greatest strength immediately postoperatively and also up to 6 weeks. The optimal end-to-end surgical repair utilizes a non-absorbable 3/0 or 4/0 braided or monofilament material as the core suture. This is supplemented with a 6/0 epitendinous suture12 which is usually a nonabsorbable monofilament suture, such as polypropylene. This allows movement between the strands and facilitates redistribution of the forces across the repair site allowing uniform loading of each strand. This theoretically reduces the risk of overloading one strand of the repair which could result in early failure. The number of core strands that cross the repair site will increase the strength of the repair,13 however multi-strand core sutures can also be problematic, with increased surgical time and tissue handling and greater bulk of the repair which can increase adhesion formation and decrease tendon gliding. A four-stranded core suture is considered the minimum and is also the optimal compromise between strength and bulk. It is therefore the most widely accepted technique. Several four-strand core suture techniques exist (Figure 3) with the double modified Kessler and cruciate repairs being the most commonly utilized. Single knotted core suture techniques (e.g. Cruciate) have been shown to be biomechanically superior to double-knotted techniques (e.g. Double Kessler, modified Becker, Tsuge).14 The length of purchase of the core suture within the tendon substance is also important and should be a minimum of 0.7 mm but preferably 10 mm. Less than 7 mm has been shown to lead to a significant reduction in the cut out strength of the core suture.9 The aim of the core suture is to approximate the tendon ends to their anatomical position at the time of repair and prevent gapping (widening of the repair site) during the rehabilitation phase. Gapping was considered by many to be undesirable as it increased the risk of adhesions, decreased glide and led to stiffness post-operatively. A canine study has subsequently shown that gapping does in fact not increase the rate of adhesion formation but if greater than 3 mm occurs, it leads to a significant reduction in the repair strength at 6 weeks.15 Therefore the principle of preventing gapping with the core suture has not
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Figure 3 Diagram of six four-stranded suture techniques for flexor tendon repair. a Modified Becker, b modified double Tsuge, c Lee, d locked cruciate, e Robertson, and f Strickland.
changed but the justification for it, has. Some surgeons advocate over tightening the core suture by 10% creating slight tension at the repair site to compensate for muscle tension during the rehabilitation phase and reduce gapping.9 In addition to the core suture an epitendinous suture is routinely used and provides several functions. Firstly it increases the initial repair strength and further prevents gapping leading to greater repair strength at 6 weeks. Secondly the epitendinous suture decreases the bulk and tidies the outer surface of the repair leading to improved tendon gliding. In Zone 1 injuries within 1 cm of the FDP insertion a fourstranded core suture is placed through the tendon stump (double Kessler, modified Becker) the four free strands are then passed around or through the distal phalanx and tied over a button on the nail plate that is left for 6 weeks before being cut. There is no need for an epitendinous suture in these cases.
Rehabilitation The correct and timely rehabilitation is fundamental to achieving optimal functional outcomes. The rehabilitation program is concerned with establishing a Total Active Motion (TAM), pinch and power grip equivocal to the contralateral side whilst avoiding the potential complications of re-rupture, adhesion formation and flexion contracture. The decisions to be made when considering rehabilitation include; early vs. delayed mobilization, splintage (dynamic vs. passive), splint position (wrist held flexed, neutral or extended), controlled mobilization protocol (controlled passive motion, active extension/passive flexion or controlled active motion). Objective assessment tools to measure functional outcome and time to completion of the rehabilitation program are also important factors. Although the end goal is clear, there still remains insufficient evidence to define the best mobilization strategy.7,16 The traditional practice of enforced immobilization for 3 weeks post-flexor repair has now been almost universally abandoned. This is due to the resultant high rates of adhesion formation and flexion contractures, which inevitably produced grossly unsatisfactory functional outcomes. Additionally, a good deal of experimental evidence would suggest that motion
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stimulates tendon repair, with active motion increasing the strength of the repair while decreasing oedema and tendon softening.17 It is therefore widely accepted that early post-operative mobilization, usually around day 3 post-surgery, regardless of the controlled mobilization protocol employed, is best clinical practice. The choice of controlled mobilization program employed continues to be the source of much debate. The majority of the evidence is centred about Zone II flexor tendon injuries and their subsequent outcomes, often being regarded as the ‘yardstick’. There has been a gradual shift from passive towards more active mobilization protocols. This is due to a combination of our improved understanding regarding the biology of flexor tendon healing and improved surgical techniques. The evidence in the literature supports the use of early active mobilization protocols after Zone II flexor tendon repair.13,17e19 The origins of immediate controlled mobilization as opposed to delayed mobilization were historically outlined by Kleinert’s classical description of controlled active extension with passive flexion utilizing elastic band traction. Duran and Houser used a protective dorsal block splint without elastic bands, and used controlled passive flexion by the therapist or contralateral hand, with only 3e5 mm of tendon motion. This regime, supported by the Louisville group, was considered satisfactory in preventing adhesion formation whilst protecting the surgical repair, and decreasing incidence of PIPJ contracture.20 These results however were not uniformly reproducible and disappointing functional results led to the advent of early active mobilization. The early active regime was initially described by the Belfast group, who demonstrated that early active mobilization regimens following flexor tendon repair limited adhesion formation and improved functional outcome.17 Furthermore Kleinert’s (active extension not against resistance and passive flexion with rubber bands) rehabilitation regimen has fallen out of vogue due to the increasingly common associated complication of permanent flexion contractures of the PIP joint with the use of elastic band traction. This was due to the resting position of the PIP joint, maintained in 60 e90 of flexion.18 Similarly Duran’s (controlled passive motion) has been associated with a poor capacity for differential gliding between the superficialis and profundus tendons, in particular in Zone II. This eventually leads to adhesion formation that compromises the functional result.21 The post-operative regime detailed by the Belfast group involved the affected hand being placed in a complete plaster-ofParis cast on the forearm with a dorsal slab to the fingertips with the wrist in mid-flexion (30e40 ), the MCPJs at/or slightly less than 90 and the interphalangeal joints in neutral. This choice of hand splint position is well supported in the literature.19,22,23 The significance of the splintage position is designed to minimize the tension across the flexor repair, and different positions have been identified as being potentially superior to the original splintage position described by the Belfast group, demonstrating that a position of extension of the wrist and flexion of the MCP joints produces the least tension on the repaired tendon, at least during attempts at active digital flexion.13 It has also been observed that it is easier to mobilize the fingers actively with the wrist straight. The incidence of rupture, regardless of method of mobilization regimen utilized post-operatively, is consistently quoted at 4e6%.19
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The Belfast (controlled active motion) regimen commences rehabilitative exercises 48 h after the flexor repair, under the supervision of a specialist hand-therapist. These exercises are performed at 2-hourly intervals throughout the course of the day. The regimen initially involves two passive movements followed by two active movements of the affected digit. The aim is to achieve full passive flexion and extension, and around 30 and 10 of active flexion at the PIP and DIP joints respectively by the end of the first week. Over the next 5 weeks (up to 6 weeks postflexor repair), the aim was to achieve active flexion of 90 in the PIPJ and 60 in the DIPJ. Despite there being a perplexing variety of protocols in the literature, certain essential design principles lead to comparable clinical outcomes. This illustrates the fact that slight alterations in the angles to which the joints should be flexed, or the number of repetitions of exercise in each episode of mobilization, are perhaps not significant.9 A controlled active flexion regimen has been outlined by Tang. The hand is protected post-operatively in a thermoplastic splint with slight wrist flexion (20 e30 ), the MCP joints in slight flexion and the IP joints in extension (Figure 4). No movement is encouraged during the first 48 h to allow pain and oedema to settle. On days 3e5 post-operatively ten passive ‘warm up’ finger flexion exercises are performed followed by 20e30 gentle active flexion exercises. This is conducted morning, noon and night over the first 2 weeks, and towards the end of this period the number of blocks of exercises can be increased to 5e6 times per day. Full active flexion is not encouraged, but full extension either actively or passively is important during this initial phase to avoid an extensor lag. At the end of the second week the position of the thermoplastic splint is changed, to incorporate 30
Figure 4 Photograph of thermoplastic splint typically used in early active mobilization protocols.
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MINI-SYMPOSIUM: THE HAND
of wrist extension. Over weeks 3e5 active flexion up to the midrange is now a minimum, but flexion over the final third of the flexion range may need to be performed just passively if the fingers encounter undue resistance. This is because the tendons can experience stress 5e10 times that encountered during the final third of the flexion range compared to the previous two thirds. Ensuring full passive flexion throughout the rehabilitation program is essential to prevent dorsal ligament tightening and extensor tethering. At the end of the fifth week full active flexion is encouraged and at the end of week 6 the splint can be discarded except at nighttime. At week 8 the finger can be utilized normally. By changing the wrist position at 2.5 weeks, emphasis can be shifted from achieving full extension to achieving full flexion, enabling the full range of intended motion to be achieved with relative ease while diminishing the risk of joint contractures and the risk of rupture of tendon repairs.9 Emphasis must be placed on the importance of patient education during the rehabilitation process and the need for the patient to strictly follow the regime. Failing to do so places the repair in serious jeopardy. Table 1 outlines critical areas that the patient must understand.
determine the functional success of flexor repairs. Grip strength, pinch strength, finger dexterity (Nine Hole Peg Test e NHPT), DASH (Disabilities of Arm, Shoulder and Hand) score, hand disability in daily living activities and quality of motion including flexion arc, digital coordination and speed of movement were all additional suggested outcome measures for flexor tendon repair. Grip strength, as detailed by the American Society of Hand Therapists, is assessed with the shoulder in a neutral adducted and rotated position and the wrist at 30 of dorsiflexion and 15 of ulnar deviation. Measurements are performed using a Jamar dynamometer and assumed that the dominant hand normally had a power of 100e120% of the non-dominant hand. Achieving 80 and 60% power in an injured dominant and non-dominant hand post-repair respectively, compared to a normal contralateral hand was associated with a good functional outcome. The TAM, grip and pinch outcome measures can all be objectively assessed using a goniometer and appropriate dynamometers, however currently instruments have not yet been developed for measuring the speed of motion and digital coordination. Although functional questionnaires have proved to be very useful tools in evaluating the results of many diseases, a specific questionnaire has not yet been used for flexor tendon repair.24
Outcome measures The functional outcome post-flexor repair is the objective evidence for both the patient and the surgical team. Historically, the range of total active motion (TAM) was the sole outcome measured. This concept was introduced by the American Society for Surgery of the Hand (ASSH). The TAM was divided into those with 100%, 75e90%, 50e74% and less than 50% of the corresponding digit in the contralateral hand and considered respectively to be an excellent, good, fair or poor functional outcome. Strickland and Glogovac devised a similar evaluation of the TAM, where 85e100%, 70e84%, 50e69% and less than 50% was an excellent, good, fair or poor functional outcome. Strickland’s original evaluation system was calculated as; the sum of active flexion at the PIP and DIP joints minus the sum of the extensor deficient at both the PIP and DIP joints divided by 1.75 to give a percentage TAM of the considered normal range. Good correlation has been found between the Total Active Motion (TAM) and the original Strickland test (kappa ¼ 0.85).24 Subsequently, hand specialists identified the requirement for a greater breadth of the evaluation tools to more accurately
Conclusion Flexor tendon injuries occur frequently. They are often disabling and are challenging injuries to treat successfully. Meticulous surgical repair typically within the first week, utilizing a fourstranded, non-absorbable 3/0 or 4/0 monofilament with a single knot cruciate repair and augmented by a 6/0 epitendinous circumferential suture is recommended. Early post-operative mobilization typically involving a controlled active rehabilitation protocol is currently favoured in order to avoid adhesion formation and flexion contractures. The complication rates for early active mobilization are similar to the passive rehabilitation protocols. Despite a vast array of studies concerned with flexor tendon rehabilitation no definitive evidence exists to support any particular early mobilization protocol. A
REFERENCES 1 Verdan CE. Primary repair of flexor tendons. J Bone Joint Surg 1960; 42A: 647e57. 2 Kleinert HE, Kutz JE, Ashbell T, Martinez E. Primary repair of lacerated flexor tendons in “No man’s land”. In: Proceedings of the American society for the surgery of the hand. J Bone Joint Surg 1967; 49A: 577. 3 Bunnell S. Repair of tendons in the fingers. Surg Gynecol Obstet 1920; 35: 88e97. 4 Strickland JW. Development of flexor tendon surgery: twenty-five years of progress. J Hand Surg Am 2000; 25: 214e35. 5 Strickland JW. The scientific basis for advance in flexor tendon surgery. J Hand Ther; 2005. 6 Weber ER. Synovial fluid nutrition of flexor tendons. Orthop Res Soc 1979; 4: 227. 7 Thien TB, Becker JH, Theis JC. Rehabilitation after surgery for flexor tendon injuries in the hand. Cochrane Libr 2009; 3: 1e25 [Review]. 8 Bright DS, Urbaniak JS. Direct measurements of flexor tendon tension during active and passive digit motion and its application to flexor tendon surgery. Orthop Trans 1977; 1: 4e5.
Advice and education that the patient should receive on entering post-operative rehabilitation with the hand specialist 1. 2. 3. 4. 5. 6. 7. 8.
No use of the hand for a minimum 4 weeks No driving 8e10 weeks No removing of the splint Return to work advice (depends on occupation and hand dominance) How to care for the splint? What to do if the splint breaks? What to do if the finger stops bending? (Tendon rupture) Advice regards wound care and signs of infection
Table 1
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9 Tang JB. Indications, methods, postoperative motion and outcome evaluation of primary flexor tendon repairs in zone 2. J Hand Surg 2007; 32E: 118e29. 10 McFarlane RM, Lamon R, Jarvis G. Flexor tendon injuries within the finger. A study of the results of the tendon suture and tendon graft. J Trauma 1968; 8: 987e1003. 11 Sourmelis SG, McGrouther DA. Retrieval of the retracted flexor tendon. J Hand Surg Br 1987; 12: 109e11. 12 Langley C, Hobby J. Focus on flexor tendon repair. J Bone Joint Surg Br 2009; 22: 1e3. 13 Savage R, Risitano G. Flexor tendon repair using a ‘six strand’ method of repair and early active mobilization. J Hand Surg 1989; 14B: 396e9. 14 Rees L, Matthews A, Masouros SD, Bull AMJ, Haywood R. Comparison of 1 and 2 knot, 4-strand, double modified Kessler tendon repairs in a porcine model. J Hand Surg 2009; 34A: 705e9. 15 Gelberman RH, Boyer MI, Brodt MD, Winters SC, Silva MJ. The effect of gap formation at the repair site on the strength and excursion of the intrasynovial flexor tendons. An experimental study on the early stages of tendon healing on dogs. J Bone Joint Surg Am 1998; 81: 975e82. 16 Ling PT, Tan ABH. Role of controlled mobilization following flexor tendon repair in the hand: a systematic review. SGH Proc 2006; 15: 2e6.
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17 Small JO, Brenna MD, Colville J. Early active mobilization following flexor tendon repair in zone 2. J Hand Surg 1989; 14B: 383e91. 18 Bainbridge LC, Robertson C, Gillies D, Elliot D. A comparison of postoperative mobilization of flexor tendon repairs with ‘passive flexioneactive extension’ and ‘controlled active motion’ techniques. J Hand Surg 1994; 19B: 517e21. 19 Baktir A, Turk CY, Kabak S, Sahin V, Kardas Y. Flexor tendon repair in zone 2 followed by early active mobilization. J Hand Surg 1996; 21B: 624e8. 20 Lister GD, Kleinert HE, Kutz JE, Atasoy E. Primary flexor tendon repair followed by immediate controlled mobilization. J Hand Surg 1977; 6: 441e51. 21 Silfverskiold KL, May EJ, Tornvall AH. Flexor digitorum profundus tendon excursions during controlled motion after flexor repair in zone II: a prospective clinical study. J Hand Surg Am 1992; 17: 122e31. 22 Deniz E, Ayse K, Sehim K, Mehmet D, Aysun S. Postoperative management of flexor tendon repair in zone 2. J Phys Ther Sci 2000; 12: 63e6. 23 Pang, et al. Active mobilization after flexor tendon repair: comparison of results following injuries in zone 2 and other zones. J Ortho Surg 2005; 13: 158e63. 24 Libberecht K, Lafaire C, Van Hee R. Evaluation and functional assessment of flexor tendon repair in the hand. Acta Chir Belg 2006; 106: 560e5.
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(vi) Flexor tendon injuries
The goal of surgical repair has remained the same since Verdan and Kleinert’s early work that is: to achieve a primary tendon repair with sufficient tensile strength to allow the instigation of a post-operative rehabilitation regime which prevents adhesion formation and stimulates the restoration of gliding surfaces and repair site healing.4
P A G Torrie N Atwal D Sheriff A Cowey
Anatomy The flexor digitorum superficialis (FDS) originates from the volar surface of the humerus, ulna, and radius. In the midsection of the forearm, the FDS muscle belly divides into four distinct bundles, which separate into a superficial and a deep layer; the tendons in the superficial layer act upon the middle and ring fingers, and the deep layer tendons act upon the index and little fingers. The FDS tendon to the small finger may not be present in all individuals. The common muscle belly of the flexor digitorum profundus (FDP) originates from the anterior-medial aspect of the ulna and interosseous membrane and is dorsal to FDS in the volar aspect of the forearm. In the hand at the level of the A1 pulley the FDS tendon bifurcates, allowing the deeper FDP tendon to pass distally to its insertion at the base of the distal phalanx. The two limbs of the FDS tendon deviate from the midline, wrapping around profundus (known as Camper’s chiasm), before ultimately inserting dorsal to the profundus tendon on the volar surface of the proximal half of the middle phalanx. There is a predictable arrangement of five annular pulleys and three cruciform pulleys in the fingers, described initially by Doyle and Blythe and with the subsequent description by Hunter of a fifth annular pulley.5 The arrangement in the thumb includes two annular and an oblique pulley. The A1, A3, and A5 pulleys originate from the palmar plates of the MCP, PIP, and the DIP joints, respectively. The A2 and A4 pulleys are continuous with the periosteum of the proximal half of the proximal phalanx and of the middle third of the middle phalanx, respectively. The cruciform pulleys are located between the A2 and A3 pulleys (C1), between the A3 and A4 pulleys (C2), and between the A4 and A5 pulleys (C3) (Figure 1). The annular pulley arrangement provides tendon constraint with an optimal moment arm to maximize joint motion for a given amount of tendon excursion. Flexor tendon nutrition is received from both vascular (intrinsic) and synovial (extrinsic) sources. Three vascular (intrinsic) supplies are routinely described; the longitudinally
Abstract Flexor tendon injuries are a commonly occurring and often challenging injury presenting to hand specialists that require meticulous surgical repair and early post-operative mobilization in order to achieve a successful functional outcome. Historically the methods of repair and post-operative rehabilitation protocols varied greatly between surgeons, and were based largely on individual experience and anecdotal evidence. Over the last three decades, extensive documentation in the literature, including basic scientific research, randomized controlled trials and a Cochrane review has provided evidence detailing improved or beneficial surgical techniques and post-operative rehabilitation protocols, aimed at ultimately improving the patients’ final functional outcome, after a flexor tendon injury.
Keywords anatomy; biomechanics; flexor tendon injuries; outcomes; rehabilitation protocol; surgical repair
Introduction The incidence of flexor tendon injuries in the UK is over 3200 per annum. Achieving normal function post-repair remains a constant challenge to hand surgeons around the world. Pioneering work in the 1960s by Verdan1 and Kleinert2 showed that the primary flexor tendon repair could be successful. This contradicted the commonly held belief at the time that excision of the divided tendon and delayed grafting, as advocated by Bunnell half a century earlier,3 yielded the best results. Since the 1960s the surgical technique, the basic science and the rehabilitation of flexor tendon repair have been the subject of numerous scientific studies both in vivo and ex vivo. Yet, despite the vast volume of literature and the advances made in all aspects of repair, a widely accepted definitive management protocol, leading to predictable results, has yet to be established.
P A G Torrie MB ChB MRCS (eng) Orthopaedic Registrar at the Royal United Hospital Bath NHS Trust, Combe Park, Bath BA1 3NG, UK. N Atwal MB ChB BSc (hons) MRCS (eng) Orthopaedic Registrar at the Orthopaedic registrar. Royal United Hospital Bath NHS Trust, Combe Park, Bath BA1 3NG, UK. D Sheriff BSc MCSP Specialist Hand Physiotherapist at the Royal United Hospital Bath NHS Trust, Combe Park, Bath BA1 3NG, UK. A Cowey MB ChB FRCS (T þ O) Hand Dip Surg Consultant Hand Surgeon at the Royal United Hospital Bath NHS Trust, Combe Park, Bath BA1 3NG, UK.
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Figure 1 Picture of the arrangement of pulleys in the flexor sheath.
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The biomechanical properties in vivo of a flexor tendon directly correlate with the strength required in the surgical repair, necessary to allow optimal rehabilitation without early failure. During un-resisted passive flexion, flexor tendons are subjected to 2e4 N of force. Active flexion with mild and moderate resistances subjects the flexor tendon to 10 N and 17 N of force respectively, whilst a strong composite grasp loads the flexor tendons with 70 N of force and firm tip pinch with 120 N.8
oriented vessels on the tendon surface, the vincular arrangement derived from the paired digital vessels and vessels of intraosseous origin at the tendon insertions. Watershed areas of limited vascular supply within the tendon exist. There is a single avascular zone within the intrasynovial portion of the FDS tendon over the proximal phalanx and under the A2 pulley. There are two avascular zones within the intrasynovial portion of the FDP tendon; the first lies over the proximal phalanx deep to the A2 pulley, and the second is located over the middle phalanx, usually under the A4 pulley. Synovial (extrinsic) nutrition occurs through imbibition whereby fluid is forced into the interstices of the tendon through small ridges in the tendon surface as the digit is flexed and extended.6 The A2 and A4 pulleys are crucial for normal digital function as they prevent tendon bowstringing and provide optimal joint flexion for a given amount of tendon excursion. The flexor tendons are composed of collagen (primarily type I collagen e 78%) and non-collagenous proteins. The tendon fascicles consist of long, narrow, spiralling bundles of mature fibroblasts (tenocytes) and type 1 collagen fibres, each fascicle is covered by a thin visceral and parietal adventitia called the endotenon which separates it from the adjacent fascicle. A single tendon contains numerous fascicles that are grouped together and covered by another adventitial layer e the epitenon that has an associated fluid environment similar to synovial fluid.4 Verdan has classified flexor tendon injuries into five distinct zones of injury, which are routinely utilized by hand surgeons. The zone of injury has relevance in relation to the propensity for adhesion formation, maximally seen in Zones II and IV. Zone I is distal to the insertion of superficialis, just proximal of the distal interphalangeal joint, therefore affects the profundus only. Zone II is the region from the metacarpal head to the middle of the middle phalanx with the FDP and FDS within one flexor tendon sheath (FDP deep to FDS). Zone III is the region between the transverse carpal ligament and the proximal margin of the tendon sheath. Zone IV is deep the transverse carpal ligament, and Zone V is at the wrist, proximal to the transverse carpal ligament7 (Figure 2).
Surgical repair Prior to any surgical repair a full assessment of the injured hand should be made to identify any functional, neurovascular deficits as well as issues pertaining to skin coverage and the integrity of the underlying bony skeleton. This assessment should guide the surgeon as to which structures are potentially damaged and direct the informed consent and intended surgical pathway. In tendon divisions ultrasound may be useful in identifying the location of the proximal tendon end preoperatively as may the presence of palm tenderness on clinical examination. The timing of surgical repair is not clear and evidence is anecdotal, some have claimed it should be done as soon as possible post-injury, others within 72 h with more recent opinion suggesting a delay of 4e7 days is advisable, allowing the swelling to reduce.9 What is clear is the outcomes are improved if an appropriately trained surgeon undertakes the procedure even if it is several days’ post-injury as opposed to an inexperienced surgeon attempting repair immediately after division. The time frame beyond which primary repair is not recommended is equally unclear, delay beyond 7 days is unadvisable due to the potential risk of tendon ends becoming rounded and possibly adherent, sheath collapse and fibrosis as well as myotendinous retraction, all of which make the procedure technically more demanding. There is documented evidence of successful repair beyond a month10 but in cases beyond 7 days’ post-injury the operating surgeon must be prepared to encounter tendon ends that cannot be approximated and consider an alternative surgical strategy in these circumstances. Repair should be performed in an operating theatre with good lighting under general or regional anaesthetic with the use of a brachial tourniquet and preferably loupe magnification. The key to successful surgical outcomes in all procedures is meticulous tissue handling but this is never truer than in flexor tendon repairs. Poor tissue handling damages the tendon surfaces and surrounding structures and increases the risk of fibrosis and secondary adhesions. The surgical approach is either a mid lateral or Bruner incision where possible incorporating the original laceration. Thick skin flaps should be raised and the flexor sheath exposed ensuring the neurovascular bundles are identified and protected throughout. Once the sheath is exposed the distal end of the divided flexor tendon is usually easily identified and it is the proximal end that has commonly retracted. The proximal stump maybe delivered into the wound with gentle proximal to distal milking, once visible the stump maybe brought through the sheath carefully using fine-toothed forceps (avoid passing instruments blindly down the tendon sheath as it increase the risk of intrasynovial damage and secondary adhesions). If the proximal tendon stump cannot be milked into the wound it can be identified more proximal via a separate incision and an infant feeding tube passed from distal to proximal is then
Figure 2 Verdan’s flexor zones.
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sutured to the tendon proximally and tube pulled distally delivering the stump into the wound.11 Care must be taken to preserve the flexor sheath as much as possible during this component of the surgery; traditional teaching is to preserve the A2 and A4 pulleys at all costs in order to prevent tendon bowstringing and subsequent loss of finger joint movement. More recent work has suggested that if necessary release of the A2 or A4 pulleys in isolation is acceptable as placing a tendon repair beneath one of these strong unyielding pulleys may compromise tendon gliding and therefore surgical outcome.9 Once the tendon ends have been delivered into the wound attention should be focused on the repair. If the tendon laceration is in Zone 1 of the flexor sheath and within 1 cm of the FDP insertion into the distal phalanx, an end-to-end repair should not be attempted. Instead, a tendon to bone repair should be performed. If the laceration is greater than 1 cm from the FDP insertion in Zone 1 or in Zones 2e5 a direct end-to-end tendon repair should be undertaken. In cases where both FDP and FDS are divided an attempt should be made to repair both tendons as sacrificing the FDS limits the reconstructive options if the FDP repair fails. Considerable work has been done to try and identify the repair technique producing the greatest strength immediately postoperatively and also up to 6 weeks. The optimal end-to-end surgical repair utilizes a non-absorbable 3/0 or 4/0 braided or monofilament material as the core suture. This is supplemented with a 6/0 epitendinous suture12 which is usually a nonabsorbable monofilament suture, such as polypropylene. This allows movement between the strands and facilitates redistribution of the forces across the repair site allowing uniform loading of each strand. This theoretically reduces the risk of overloading one strand of the repair which could result in early failure. The number of core strands that cross the repair site will increase the strength of the repair,13 however multi-strand core sutures can also be problematic, with increased surgical time and tissue handling and greater bulk of the repair which can increase adhesion formation and decrease tendon gliding. A four-stranded core suture is considered the minimum and is also the optimal compromise between strength and bulk. It is therefore the most widely accepted technique. Several four-strand core suture techniques exist (Figure 3) with the double modified Kessler and cruciate repairs being the most commonly utilized. Single knotted core suture techniques (e.g. Cruciate) have been shown to be biomechanically superior to double-knotted techniques (e.g. Double Kessler, modified Becker, Tsuge).14 The length of purchase of the core suture within the tendon substance is also important and should be a minimum of 0.7 mm but preferably 10 mm. Less than 7 mm has been shown to lead to a significant reduction in the cut out strength of the core suture.9 The aim of the core suture is to approximate the tendon ends to their anatomical position at the time of repair and prevent gapping (widening of the repair site) during the rehabilitation phase. Gapping was considered by many to be undesirable as it increased the risk of adhesions, decreased glide and led to stiffness post-operatively. A canine study has subsequently shown that gapping does in fact not increase the rate of adhesion formation but if greater than 3 mm occurs, it leads to a significant reduction in the repair strength at 6 weeks.15 Therefore the principle of preventing gapping with the core suture has not
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Figure 3 Diagram of six four-stranded suture techniques for flexor tendon repair. a Modified Becker, b modified double Tsuge, c Lee, d locked cruciate, e Robertson, and f Strickland.
changed but the justification for it, has. Some surgeons advocate over tightening the core suture by 10% creating slight tension at the repair site to compensate for muscle tension during the rehabilitation phase and reduce gapping.9 In addition to the core suture an epitendinous suture is routinely used and provides several functions. Firstly it increases the initial repair strength and further prevents gapping leading to greater repair strength at 6 weeks. Secondly the epitendinous suture decreases the bulk and tidies the outer surface of the repair leading to improved tendon gliding. In Zone 1 injuries within 1 cm of the FDP insertion a fourstranded core suture is placed through the tendon stump (double Kessler, modified Becker) the four free strands are then passed around or through the distal phalanx and tied over a button on the nail plate that is left for 6 weeks before being cut. There is no need for an epitendinous suture in these cases.
Rehabilitation The correct and timely rehabilitation is fundamental to achieving optimal functional outcomes. The rehabilitation program is concerned with establishing a Total Active Motion (TAM), pinch and power grip equivocal to the contralateral side whilst avoiding the potential complications of re-rupture, adhesion formation and flexion contracture. The decisions to be made when considering rehabilitation include; early vs. delayed mobilization, splintage (dynamic vs. passive), splint position (wrist held flexed, neutral or extended), controlled mobilization protocol (controlled passive motion, active extension/passive flexion or controlled active motion). Objective assessment tools to measure functional outcome and time to completion of the rehabilitation program are also important factors. Although the end goal is clear, there still remains insufficient evidence to define the best mobilization strategy.7,16 The traditional practice of enforced immobilization for 3 weeks post-flexor repair has now been almost universally abandoned. This is due to the resultant high rates of adhesion formation and flexion contractures, which inevitably produced grossly unsatisfactory functional outcomes. Additionally, a good deal of experimental evidence would suggest that motion
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stimulates tendon repair, with active motion increasing the strength of the repair while decreasing oedema and tendon softening.17 It is therefore widely accepted that early post-operative mobilization, usually around day 3 post-surgery, regardless of the controlled mobilization protocol employed, is best clinical practice. The choice of controlled mobilization program employed continues to be the source of much debate. The majority of the evidence is centred about Zone II flexor tendon injuries and their subsequent outcomes, often being regarded as the ‘yardstick’. There has been a gradual shift from passive towards more active mobilization protocols. This is due to a combination of our improved understanding regarding the biology of flexor tendon healing and improved surgical techniques. The evidence in the literature supports the use of early active mobilization protocols after Zone II flexor tendon repair.13,17e19 The origins of immediate controlled mobilization as opposed to delayed mobilization were historically outlined by Kleinert’s classical description of controlled active extension with passive flexion utilizing elastic band traction. Duran and Houser used a protective dorsal block splint without elastic bands, and used controlled passive flexion by the therapist or contralateral hand, with only 3e5 mm of tendon motion. This regime, supported by the Louisville group, was considered satisfactory in preventing adhesion formation whilst protecting the surgical repair, and decreasing incidence of PIPJ contracture.20 These results however were not uniformly reproducible and disappointing functional results led to the advent of early active mobilization. The early active regime was initially described by the Belfast group, who demonstrated that early active mobilization regimens following flexor tendon repair limited adhesion formation and improved functional outcome.17 Furthermore Kleinert’s (active extension not against resistance and passive flexion with rubber bands) rehabilitation regimen has fallen out of vogue due to the increasingly common associated complication of permanent flexion contractures of the PIP joint with the use of elastic band traction. This was due to the resting position of the PIP joint, maintained in 60 e90 of flexion.18 Similarly Duran’s (controlled passive motion) has been associated with a poor capacity for differential gliding between the superficialis and profundus tendons, in particular in Zone II. This eventually leads to adhesion formation that compromises the functional result.21 The post-operative regime detailed by the Belfast group involved the affected hand being placed in a complete plaster-ofParis cast on the forearm with a dorsal slab to the fingertips with the wrist in mid-flexion (30e40 ), the MCPJs at/or slightly less than 90 and the interphalangeal joints in neutral. This choice of hand splint position is well supported in the literature.19,22,23 The significance of the splintage position is designed to minimize the tension across the flexor repair, and different positions have been identified as being potentially superior to the original splintage position described by the Belfast group, demonstrating that a position of extension of the wrist and flexion of the MCP joints produces the least tension on the repaired tendon, at least during attempts at active digital flexion.13 It has also been observed that it is easier to mobilize the fingers actively with the wrist straight. The incidence of rupture, regardless of method of mobilization regimen utilized post-operatively, is consistently quoted at 4e6%.19
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The Belfast (controlled active motion) regimen commences rehabilitative exercises 48 h after the flexor repair, under the supervision of a specialist hand-therapist. These exercises are performed at 2-hourly intervals throughout the course of the day. The regimen initially involves two passive movements followed by two active movements of the affected digit. The aim is to achieve full passive flexion and extension, and around 30 and 10 of active flexion at the PIP and DIP joints respectively by the end of the first week. Over the next 5 weeks (up to 6 weeks postflexor repair), the aim was to achieve active flexion of 90 in the PIPJ and 60 in the DIPJ. Despite there being a perplexing variety of protocols in the literature, certain essential design principles lead to comparable clinical outcomes. This illustrates the fact that slight alterations in the angles to which the joints should be flexed, or the number of repetitions of exercise in each episode of mobilization, are perhaps not significant.9 A controlled active flexion regimen has been outlined by Tang. The hand is protected post-operatively in a thermoplastic splint with slight wrist flexion (20 e30 ), the MCP joints in slight flexion and the IP joints in extension (Figure 4). No movement is encouraged during the first 48 h to allow pain and oedema to settle. On days 3e5 post-operatively ten passive ‘warm up’ finger flexion exercises are performed followed by 20e30 gentle active flexion exercises. This is conducted morning, noon and night over the first 2 weeks, and towards the end of this period the number of blocks of exercises can be increased to 5e6 times per day. Full active flexion is not encouraged, but full extension either actively or passively is important during this initial phase to avoid an extensor lag. At the end of the second week the position of the thermoplastic splint is changed, to incorporate 30
Figure 4 Photograph of thermoplastic splint typically used in early active mobilization protocols.
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of wrist extension. Over weeks 3e5 active flexion up to the midrange is now a minimum, but flexion over the final third of the flexion range may need to be performed just passively if the fingers encounter undue resistance. This is because the tendons can experience stress 5e10 times that encountered during the final third of the flexion range compared to the previous two thirds. Ensuring full passive flexion throughout the rehabilitation program is essential to prevent dorsal ligament tightening and extensor tethering. At the end of the fifth week full active flexion is encouraged and at the end of week 6 the splint can be discarded except at nighttime. At week 8 the finger can be utilized normally. By changing the wrist position at 2.5 weeks, emphasis can be shifted from achieving full extension to achieving full flexion, enabling the full range of intended motion to be achieved with relative ease while diminishing the risk of joint contractures and the risk of rupture of tendon repairs.9 Emphasis must be placed on the importance of patient education during the rehabilitation process and the need for the patient to strictly follow the regime. Failing to do so places the repair in serious jeopardy. Table 1 outlines critical areas that the patient must understand.
determine the functional success of flexor repairs. Grip strength, pinch strength, finger dexterity (Nine Hole Peg Test e NHPT), DASH (Disabilities of Arm, Shoulder and Hand) score, hand disability in daily living activities and quality of motion including flexion arc, digital coordination and speed of movement were all additional suggested outcome measures for flexor tendon repair. Grip strength, as detailed by the American Society of Hand Therapists, is assessed with the shoulder in a neutral adducted and rotated position and the wrist at 30 of dorsiflexion and 15 of ulnar deviation. Measurements are performed using a Jamar dynamometer and assumed that the dominant hand normally had a power of 100e120% of the non-dominant hand. Achieving 80 and 60% power in an injured dominant and non-dominant hand post-repair respectively, compared to a normal contralateral hand was associated with a good functional outcome. The TAM, grip and pinch outcome measures can all be objectively assessed using a goniometer and appropriate dynamometers, however currently instruments have not yet been developed for measuring the speed of motion and digital coordination. Although functional questionnaires have proved to be very useful tools in evaluating the results of many diseases, a specific questionnaire has not yet been used for flexor tendon repair.24
Outcome measures The functional outcome post-flexor repair is the objective evidence for both the patient and the surgical team. Historically, the range of total active motion (TAM) was the sole outcome measured. This concept was introduced by the American Society for Surgery of the Hand (ASSH). The TAM was divided into those with 100%, 75e90%, 50e74% and less than 50% of the corresponding digit in the contralateral hand and considered respectively to be an excellent, good, fair or poor functional outcome. Strickland and Glogovac devised a similar evaluation of the TAM, where 85e100%, 70e84%, 50e69% and less than 50% was an excellent, good, fair or poor functional outcome. Strickland’s original evaluation system was calculated as; the sum of active flexion at the PIP and DIP joints minus the sum of the extensor deficient at both the PIP and DIP joints divided by 1.75 to give a percentage TAM of the considered normal range. Good correlation has been found between the Total Active Motion (TAM) and the original Strickland test (kappa ¼ 0.85).24 Subsequently, hand specialists identified the requirement for a greater breadth of the evaluation tools to more accurately
Conclusion Flexor tendon injuries occur frequently. They are often disabling and are challenging injuries to treat successfully. Meticulous surgical repair typically within the first week, utilizing a fourstranded, non-absorbable 3/0 or 4/0 monofilament with a single knot cruciate repair and augmented by a 6/0 epitendinous circumferential suture is recommended. Early post-operative mobilization typically involving a controlled active rehabilitation protocol is currently favoured in order to avoid adhesion formation and flexion contractures. The complication rates for early active mobilization are similar to the passive rehabilitation protocols. Despite a vast array of studies concerned with flexor tendon rehabilitation no definitive evidence exists to support any particular early mobilization protocol. A
REFERENCES 1 Verdan CE. Primary repair of flexor tendons. J Bone Joint Surg 1960; 42A: 647e57. 2 Kleinert HE, Kutz JE, Ashbell T, Martinez E. Primary repair of lacerated flexor tendons in “No man’s land”. In: Proceedings of the American society for the surgery of the hand. J Bone Joint Surg 1967; 49A: 577. 3 Bunnell S. Repair of tendons in the fingers. Surg Gynecol Obstet 1920; 35: 88e97. 4 Strickland JW. Development of flexor tendon surgery: twenty-five years of progress. J Hand Surg Am 2000; 25: 214e35. 5 Strickland JW. The scientific basis for advance in flexor tendon surgery. J Hand Ther; 2005. 6 Weber ER. Synovial fluid nutrition of flexor tendons. Orthop Res Soc 1979; 4: 227. 7 Thien TB, Becker JH, Theis JC. Rehabilitation after surgery for flexor tendon injuries in the hand. Cochrane Libr 2009; 3: 1e25 [Review]. 8 Bright DS, Urbaniak JS. Direct measurements of flexor tendon tension during active and passive digit motion and its application to flexor tendon surgery. Orthop Trans 1977; 1: 4e5.
Advice and education that the patient should receive on entering post-operative rehabilitation with the hand specialist 1. 2. 3. 4. 5. 6. 7. 8.
No use of the hand for a minimum 4 weeks No driving 8e10 weeks No removing of the splint Return to work advice (depends on occupation and hand dominance) How to care for the splint? What to do if the splint breaks? What to do if the finger stops bending? (Tendon rupture) Advice regards wound care and signs of infection
Table 1
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9 Tang JB. Indications, methods, postoperative motion and outcome evaluation of primary flexor tendon repairs in zone 2. J Hand Surg 2007; 32E: 118e29. 10 McFarlane RM, Lamon R, Jarvis G. Flexor tendon injuries within the finger. A study of the results of the tendon suture and tendon graft. J Trauma 1968; 8: 987e1003. 11 Sourmelis SG, McGrouther DA. Retrieval of the retracted flexor tendon. J Hand Surg Br 1987; 12: 109e11. 12 Langley C, Hobby J. Focus on flexor tendon repair. J Bone Joint Surg Br 2009; 22: 1e3. 13 Savage R, Risitano G. Flexor tendon repair using a ‘six strand’ method of repair and early active mobilization. J Hand Surg 1989; 14B: 396e9. 14 Rees L, Matthews A, Masouros SD, Bull AMJ, Haywood R. Comparison of 1 and 2 knot, 4-strand, double modified Kessler tendon repairs in a porcine model. J Hand Surg 2009; 34A: 705e9. 15 Gelberman RH, Boyer MI, Brodt MD, Winters SC, Silva MJ. The effect of gap formation at the repair site on the strength and excursion of the intrasynovial flexor tendons. An experimental study on the early stages of tendon healing on dogs. J Bone Joint Surg Am 1998; 81: 975e82. 16 Ling PT, Tan ABH. Role of controlled mobilization following flexor tendon repair in the hand: a systematic review. SGH Proc 2006; 15: 2e6.
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17 Small JO, Brenna MD, Colville J. Early active mobilization following flexor tendon repair in zone 2. J Hand Surg 1989; 14B: 383e91. 18 Bainbridge LC, Robertson C, Gillies D, Elliot D. A comparison of postoperative mobilization of flexor tendon repairs with ‘passive flexioneactive extension’ and ‘controlled active motion’ techniques. J Hand Surg 1994; 19B: 517e21. 19 Baktir A, Turk CY, Kabak S, Sahin V, Kardas Y. Flexor tendon repair in zone 2 followed by early active mobilization. J Hand Surg 1996; 21B: 624e8. 20 Lister GD, Kleinert HE, Kutz JE, Atasoy E. Primary flexor tendon repair followed by immediate controlled mobilization. J Hand Surg 1977; 6: 441e51. 21 Silfverskiold KL, May EJ, Tornvall AH. Flexor digitorum profundus tendon excursions during controlled motion after flexor repair in zone II: a prospective clinical study. J Hand Surg Am 1992; 17: 122e31. 22 Deniz E, Ayse K, Sehim K, Mehmet D, Aysun S. Postoperative management of flexor tendon repair in zone 2. J Phys Ther Sci 2000; 12: 63e6. 23 Pang, et al. Active mobilization after flexor tendon repair: comparison of results following injuries in zone 2 and other zones. J Ortho Surg 2005; 13: 158e63. 24 Libberecht K, Lafaire C, Van Hee R. Evaluation and functional assessment of flexor tendon repair in the hand. Acta Chir Belg 2006; 106: 560e5.
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