Systematic Examination

Musculoskeletal Examination.

Obvious angular or rotational deformity of the digit signifies either a fracture or a ligamentous injury that requires further assessment. Realignment of a fracture or reduction of a dislocation may be required before the evaluation of flexor tendon integrity or the presence of digital neurovascular injury. If the flexor tendons are lacerated, the digit loses its inherent flexor tone and assumes an extended posture at the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints. If the tendons are completely transected, there is no active flexion and the tenodesis effect (normal increase in flexor tone) is lost with passive wrist extension.

The tendons should be examined individually in each finger. To isolate the flexor digitorum superficialis (FDS) tendon ( Figure 6.1 ), the adjacent digits are held in full extension or in mild hyperextension by the examiner at the metacarpophalangeal (MP), PIP, and DIP joints. Active flexion of the PIP joint is evaluated for each digit, and its presence indicates that the fibers of the FDS tendon are intact. The presence of active flexion does not rule out partial FDS tendon injury, however. Pain on active flexion may suggest a partial tendon injury. The flexor digitorum profundus (FDP) tendon examination is done by positioning the finger in full extension, stabilizing the middle phalanx against the examining surface, and asking the patient to flex the DIP joint actively.

A, Continuity of FDS tendon is evaluated by asking the patient to flex the finger actively while holding MP joints of the uninvolved fingers in hyperextension, and PIP and DIP joints of the uninvolved fingers in full extension. This effectively eliminates the profundus and allows the superficialis action to be evaluated. B, Middle phalanx is held firmly, and active flexion at DIP joint is carried out. This shows continuity of FDP tendon.

Diagnostic Imaging

Plain radiographs are usually obtained at the time of initial assessment while the patient is in the emergency department. Diagnostic ultrasound may be useful when the continuity of a flexor tendon is in question, or to assess a suspected partial laceration. Intraoperative fluoroscopic images may be useful, especially if indicated by the findings of surgical exploration.

Preoperative Considerations

Optimal timing of flexor tendon repair depends on the findings of a thorough history and physical examination. Emergency repair of the lacerated tendons is indicated only in the setting of altered digital perfusion that requires microvascular repair or reconstruction. If digital perfusion is compromised, or if the mechanism of injury is consistent with injury to arteries, urgent exploration and tendon repair with microvascular digital artery and nerve repair are indicated.

Primary repair done within days of the injury allows for preparation of the patient and ensures optimal conditions for the procedure. Basic science and clinical evidence suggest that it is preferable to perform tendon repair early after injury. Undue delay can be associated with changes in the tendon ends and proximal muscle that make primary tendon repair difficult. Done promptly after injury, the wound is easier to manage and the tendon ends are fresh for the repair.

In some cases of delayed presentation, or when the patient provides an unreliable history, the interval between injury and diagnosis may be unknown. In these cases, adequate preoperative consideration should be given to the possible need for tendon reconstruction and tendon repair. These more complicated cases may require the use of a primary tendon graft or placement of a tendon spacer.

In some settings, repair of both tendons is impossible. If the tendon ends are severely injured, unclean, or ragged, or if there is insufficient tendon for repair, excision of the FDS tendon and isolated repair of the FDP tendon may be the best alternative. Isolated repair of the FDP tendon creates a simpler finger and is generally associated with diminished adhesion formation in a severely traumatized digit. In cases where only repair of the FDS tendon is possible, FDP tenodesis to the middle phalanx or DIP joint fusion may be necessary. Generally, repair of both tendons is preferable for optimal gliding and strength. In select cases, excision of one slip of the FDS tendon may be necessary to diminish the bulk of the repair and facilitate gliding through the tendon sheath. The need for repair of the flexor sheath is controversial.

Repair of Zone 1 Tendon Lacerations or Avulsions

Laceration of the FDP tendon distal to the insertion of the FDS tendon or avulsion from its insertion at the base of the proximal aspect of the distal phalanx is a zone 1 injury. If the tendon is lacerated and the distal tendon stump is less than 1 cm long, FDP tendon advancement and primary repair to bone is usually indicated. If more than 1 cm of FDP stump is available for suture, primary tenorrhaphy is usually done because shortening of the FDP tendon by more than 1 cm may result in a “quadriga effect” on the intact FDP tendons. The term quadriga ( quadri meaning “four” and jungere meaning “to yoke”) refers to a Roman chariot pulled by four horses abreast. When excessive advancement of a tendon is done for the purpose of repair, it also creates tension in the other “yoked” tendons of the FDP muscle. Because of this increased tension, diminished flexion occurs in the other fingers when the injured finger is flexed.

Flexor Digitorum Profundus Avulsion.

Leddy and Packer classified FDP avulsions into three types ( Figure 6.6 ). In type I avulsions, the FDP tendon retracts into the palm and the vincular blood supply of the tendon has been disrupted. These injuries are best treated by urgent surgical repair. In type II avulsions, the tendon stump retracts to the level of the PIP joint and some vincular blood supply is preserved. In some type II cases, a primary tendon repair may be done 6 weeks after injury. A large bone fragment is attached to the stump of the FDP tendon in type III injuries. This fragment usually prevents tendon retraction proximal to the distal edge of the A4 pulley. Fracture repair using Kirschner wire or miniature screw fixation is necessary for treatment of this injury. Since Leddy and Packer’s description was created, a fourth type of injury has been identified. A type IV injury is defined as a fracture and avulsion of the FDP tendon from the fracture fragment. The stump may be located either within the tendon sheath or within the palm. Suspicion of this injury can be confirmed with advanced digital imaging; either ultrasound or magnetic resonance imaging (MRI) is appropriate. Repair of the fracture is done first, after which the tendon is advanced and affixed to the distal phalanx. In some cases with a small fracture fragment, the bone may be excised, and the tendon may be advanced and sutured into the distal phalanx. Generally, this type IV injury is more severe and may be associated with a less optimal outcome. Because the initial radiographic findings may be inconsistent with the proximal location of the flexor tendon, I recommend that all flexor tendon avulsion injuries be treated by early repair when possible.

Leddy and Packer classification of profundus avulsions. Type I : The FDP tendon is avulsed from its insertion and retracts into the palm. Type II : The profundus tendon is avulsed from its insertion, but the stump remains within the digital sheath, implying that the vinculum longum profundus is still intact. Type III : A bony fragment is attached to the tendon stump, which remains within the flexor sheath. Further proximal retraction is prevented at the distal end of the A4 pulley.

(Copyright Elizabeth Martin.)

Repair of Zone 2 Tendon Lacerations

Attempts to improve the strength of flexor tendon repairs have focused on strategies to vary the material properties of the suture, the suture caliber, and the suture technique to coapt the tendon ends accurately. A smooth tendon suture is important for restoration of a low-friction gliding surface and facilitates tendon rehabilitation. Generally, surgeons need to master a method that allows for atraumatic suture placement and stable, accurate coaptation of the tendon ends. The method of tendon coaptation must be strong enough to allow early digital mobilization.

Core Sutures.

Ex vivo and in vivo investigations in clinically relevant models have suggested that core suture configurations with the greatest tensile strength are those in which there are multiple sites of tendon-suture integration. Although two-strand suture methods (Kessler and modified Kessler and Tajima techniques) still enjoy widespread acceptance, newer multistrand suture methods (Strickland, cruciate, Becker, Savage, and Winters) are being used with increasing frequency because they are stronger and have increased resistance to repair site gapping ( Figures 6.7 and 6.8 andVideo 6.1 ). These more modern methods of core tendon suture placement have not only been shown to offer greater initial repair site tensile strength but also to improve strength 6 weeks postoperatively.

Commonly used techniques for end-to-end flexor tendon repair.

(Copyright Elizabeth Martin.)

Comparison of ultimate force versus time between suture techniques from 0 to 21 days. The repairs with the eight-strand technique were significantly stronger than the repairs that used the four-strand technique. Asterisks denote a significant difference between the eight-strand and four-strand techniques at P < .05.

(Redrawn from Boyer MI, Gelberman RH, Burns ME, et al: Intrasynovial flexor tendon repair: an experimental study comparing low and high levels of in vivo force during rehabilitation in canines, J Bone Joint Surg [Am] 83:891–899, 2001.)

It is well accepted that core suture strength is related to the type of suture material, the caliber of the suture, and the number of suture strands crossing the repair site. This concept holds true in time-zero mechanical studies and in clinical studies for the first 6 weeks after repair. The practical limitation of the more esoteric repairs is the time required and the complexity of suture placement in a small space using a minimally traumatic technique. Most surgeons choose the suture size based on the caliber of the tendon to be repaired because a 3-0 suture shows increased strength compared with a 4-0 suture. Ex vivo studies have shown that the loop of the core suture that is positioned to “lock” rather than “grasp” the tendon stumps shows greater time-zero strength. Similarly, increasing the number of locks or grasps increases the time-zero tensile strength ( Figure 6.9 ).

Relationship between the longitudinal and transverse intratendinous components of the core suture defines whether the suture is “locking” or “grasping.” When the transverse component passes within the tendon superficial to the longitudinal component, the suture “locks” a bundle of tendon fibers. When the transverse component passes deep to the longitudinal component, however, the suture does not “lock” a bundle of tendon fibers but pulls through the tendon.

(Copyright Elizabeth Martin.)

The placement of the suture knot either within or away from the repair site has not been shown to have an independent effect on tensile strength. Greater quantity of suture within the repair site may increase repair site bulk, increase the work of flexion, and diminish the surface area available for repair. External knot placement distant to the repair site may also adversely affect tendon gliding within the flexor tendon sheath by causing increased friction or knot trapping between tendon and sheath.

Gap Formation.

There is a negative effect of early repair site gap formation on tendon healing and accrual of repair site strength. An in vivo canine study showed that tendons healing without repair site gaps, or with gaps of less than 3 mm, acquire strength 6 weeks after repair. In this same study, if there was a repair site gap greater than 3 mm, significant accrual of repair site strength did not occur. Repair site gaps that develop early in the postoperative period pose a greater risk of rupture as rehabilitation progresses after 3 weeks ( Figure 6.10 ).

Ultimate tensile strength is plotted as function of time. Tendons with repair site gaps less than 3 mm accrue strength during the fourth to sixth week postoperatively, whereas tendons with repair site gaps greater than 3 mm show no significant increase in ultimate tensile strength during the early postoperative period.

(Redrawn from Gelberman RH, Boyer MI, Brodt MD, et al: The effect of gap formation at the repair site on the strength and excursion of intrasynovial flexor tendons: an experimental study on the early stages of tendon-healing in dogs, J Bone Joint Surg [Am] 81:965–982, 1999.)

Repair of Tendon Lacerations in Zones 3, 4, and 5

The principles for operative exploration and repair of flexor tendon injuries proximal to the A1 pulley are similar to injuries in zone 2, though the potential for disruptive adhesion formation postoperatively is considerably reduced. Generally, repair of lacerations in these zones has an improved prognosis. The preoperative planning for these repairs should account for the possible need for microsurgical nerve and arterial repair. Techniques and considerations for the placement of the core and circumferential sutures and postoperative rehabilitation are the same as those described for zone 2 injuries.

Repair of Partial Tendon Lacerations

There has been considerable debate about the appropriate management of partial tendon lacerations. Partial flexor tendon lacerations can progress to late tendon rupture and tendon entrapment or triggering. For lacerations that are more than 50% of the tendon cross-sectional area, I usually repair the tendon using a core suture method and a circumferential suture. If the cross-sectional area lacerated is less than 50%, the tendon is either repaired or débrided to avoid entrapment and triggering of the tendon. My preference is to explore wounds where there is high probability on physical examination that a tendon injury has occurred. Advanced imaging can be useful in select cases for decision making but is unlikely to take the place of exploration in the majority of cases.

Author’s Preferred Technique: Zone 1 Tendon-to-Bone Repair

The patient is placed supine on the operating table, and the arm lies at a right angle to the long axis of the body. A well-padded brachial tourniquet is placed on the arm. The arm is prepared using a povidone-iodine (Betadine) scrub and paint. A surgical pause or “time out” is done. The limb is exsanguinated using an elastic bandage, and the tourniquet is inflated to a pressure that is 100 mm Hg greater than the systolic blood pressure. Prior to insufflation of the tourniquet, a first-generation cephalosporin or other appropriate antibiotic(s) is administered as determined by the nature of the injury.

When possible, an extensile midlateral incision is used to expose the flexor apparatus. This may be extended with Bruner incisions proximally and distally as needed ( Figure 6.11 ; see also Figure 6.14 ). After the exposure is completed, assessment of the entire injury is possible and the sequence of repair is determined. The tendon stump is located proximally and drawn into the distal wound by any of the techniques described for zone 2 injuries (see Figure 6.11 ). The tendon is then transfixed to the annular pulleys and the digital soft tissues with a 25-gauge needle.

Author’s preferred technique for FDP tendon reattachment to bone. A, Clinical photograph of a patient without active DIP joint flexion. B, Midlateral exposure over middle phalanx is preferred. This incision may be extended diagonally over the pulp of the finger distally and into a Bruner incision proximally. Sourmelis-McGrouther technique of proximal stump retrieval is preferred. The stump of the profundus tendon may be delivered under the A4 pulley after sequential dilation of the pulley with pediatric cervical sounds of increasing diameter. A modified Becker grasping stitch core suture is placed within the tendon stump. C, Straight Keith needles are drilled from the volar proximal base of the distal phalanx in a distal dorsal direction to exit the nail plate through the sterile matrix (distal to the lunula and eponychial fold). The individual grasping core sutures are delivered to the dorsum of the finger after placement of the needles through the holes in the button. The sutures are tied while holding the tendon directly to bone using forceps.

( B and C, Copyright Elizabeth Martin.)

It is often difficult to deliver the flared-out stump of the FDP tendon through the A4 pulley after it has avulsed from the distal phalanx and retracted proximally, particularly if several days or weeks have elapsed. Several techniques are available for this difficult situation. Sequential dilation of the A4 pulley using pediatric cervical sounds or dilators can be effective. The edges of the stump may be trimmed so that the width of the stump does not exceed that of the pulley. After sequential dilation of the pulley, a core suture is placed in the stump, and the suture strands are delivered in a proximal-to-distal direction through the pulley. With the sutures placed, gentle traction is applied to the suture ends, and the tendon can be guided through the pulley using a small flat elevator as a proximal skid. A truncated pediatric red-rubber catheter can also be used in this situation; the flared end of the catheter is cut at a width just slightly larger than the tendon and A4 pulley. The tendon core suture end may be drawn into the flared end, and the whole composite can be slid through the pulley, simultaneously dilating and passing the avulsed tendon end. In some cases, the A4 pulley must be vented at the proximal end to allow passage of the tendon. Lieber and associates ^128,129 and Tang have presented convincing mechanical and clinical evidence that the A4 pulley can be divided as needed to promote tendon gliding without adverse effects on work of flexion or functional outcome.

The bone at the volar base of the distal phalanx is exposed to establish a repair footprint for the tendon reinsertion. If the distal phalanx is large enough to accept a miniature suture anchor, I place an anchor in the center of the distal phalanx. Next, I place two corner sutures at the edge of the phalanx in the osteoperiosteal sleeve using 5-0 polypropylene. I use these sutures to seat the tendon into the footprint, and then secure the tendon into final position using the anchor suture ends. Using this technique, the tendon can be seated securely and then the grasping core suture can be more easily placed and appropriately tensioned. Two- or four-strand core suture methods can be used with this technique, and I prefer incorporating a Becker type of suture ( Figure 6.12 ). When the distal phalanx is not large enough to accommodate an anchor, I use a traditional pull-out suture. Placement of the corner sutures is still useful, however, to guide and reinforce the repair site. The pull-out sutures (a modified Kessler type of 3-0 polypropylene suture) are passed through the distal phalanges using straight Keith needles that are drilled through the footprint at the base of the distal phalanx and are tied over a button placed on the nail plate dorsally (see Figure 6.25 ). It is preferable to have the needles exit the nail plate beyond the lunula (and beyond the germinal matrix) to avoid nail deformity or eponychial injury. The button and suture are left in place for 6 weeks.

A to D, Four-strand modified Becker repair (see text).

(Copyright Elizabeth Martin.)

The rehabilitation protocol generally follows the same progression as described for zone 2 injuries (see later).

Author’s Preferred Technique: Primary Tendon Repair in Zones 1 and 2

After the initial evaluation has been done and a decision has been made in favor of early repair, the wound is irrigated with an antibiotic solution and closed with a fine monofilament suture. For clean wounds and healthy patients, I administer a weight-based dosage (1-2 g) of a first-generation cephalosporin and a tetanus toxoid when necessary. For patients who have not been immunized and for patients whose immunization status is uncertain, passive immunization may be indicated. Passive immunization is not a substitute for wound débridement. Patients who are at risk for methicillin-resistant Staphylococcus aureus or have a highly contaminated injury may require a more formal irrigation and débridement and/or broader-spectrum antibiotic coverage. A dorsal splint that includes all digits is applied. For cases that do not require urgent repair, I prefer to repair the tendon within 7 days of injury.

The patient is prepped and draped as above. The initial wound is examined, and then incisions are planned that would predictably allow access to both tendon ends. A midlateral incision is preferred because it gives wide exposure and places intact skin and subcutaneous fat directly over the flexor tendon sheath. When the laceration is complex, a midlateral approach may not be practical, and in those instances I incorporate the existing laceration into the approach to the tendon sheath ( Figures 6.13 and 6.14 ). The goal of the exposure should be to provide maximum visualization while maintaining useful durable skin flaps over the area of the tendon repair. The skin and subcutaneous fat are raised off of the tendon sheath as a single thick layer. Separation of these tissues must be avoided because skin perfusion is by random vascular supply, and thinning of the skin flap can cause decreased perfusion at the distalmost aspect of the flap. I generally design the longitudinal limb of the incision to be associated with the nerve and artery that may require repair.

Author’s technique of flexor tendon repair in zone 2. A, Knife laceration through zone 2 with digit in full flexion. The distal stumps retract distal to the skin incision with digital extension. B, Radial and ulnar extending incisions are used to allow wide exposure of the flexor tendon system. Note appearance of the flexor tendon system of the involved fingers after the retraction of skin flaps. The laceration occurred through the C1 cruciate area. Note the proximal and distal position of the flexor tendon stumps. Retraction of small flaps (windows) in the cruciate portion of synovial sheath allows the distal flexor tendon stumps to be delivered into the wound by passive flexion of DIP joint. The profundus and superficialis stumps are retrieved proximal to the wound by passive flexion of DIP joint. The profundus and superficialis stumps are retrieved proximal to the sheath by the use of a small catheter or infant feeding gastrostomy tube. C, Proximal flexor tendon stumps are maintained at the repair site by means of a transversely placed small-gauge hypodermic needle, allowing repair of the FDS slips without tension. D, Completed repair of FDS and FDP tendons is shown with DIP joint in full flexion. Extension of DIP joint delivers the repair under the intact distal flexor tendon sheath. Wound repair is done at the conclusion of the procedure.

(Copyright Elizabeth Martin.)

Incision options for wound extension during flexor tendon repair.

(Copyright Elizabeth Martin.)

The wound is completely examined to define the nature and elements of the injury. After a thorough lavage, the sequence of repairs can be determined. The laceration of the sheath is identified, and a limited débridement of the hemorrhagic ends of the sheath is performed. Exposure of the tendons is done by reflecting a radial- or ulnar-based flap of sheath within repair “windows” between the A2 and A4 annular pulleys. Sheath venting and excision should be limited to that necessary for visualization and repair, as excessive sheath division can lead to bowstringing.

If the digit was in a position of significant flexion at the time of injury, the distal stump usually lies distal to the skin laceration and may rest beneath or distal to the A4 pulley with the finger in extension. The distal tendon stump may often be delivered by passive flexion of the DIP and PIP joints. If the tendon does not pass readily, gentle sequential dilation of the A4 pulley with pediatric cervical sounds or dilators may be beneficial. Often, I place half of the core suture in the tendon distal to the pulley, and then pass the sutures and tendon end proximally beneath the pulley to complete the repair. Partial or complete A4 pulley division, pulley venting, and pulley lengthening may occasionally be necessary. I prefer to obtain a smooth repair, with full excursion on intraoperative range-of-motion testing without additional alteration of the annular pulleys when possible. Some newer studies find that this is easily done with local anesthetic methods that may facilitate intraoperative examination of tendon excursion and digital range of motion.

The proximal tendon stumps may be visible within the fibroosseous sheath. The proximal tendon end may be retrieved using a variety of methods. If the tendon is immediately accessible, I gently grasp the endotenon of the FDP and pull the tendons distally; usually the FDS tendon comes into the wound with distally applied traction on the FDP tendon. The tendon position is maintained by placement of a 25-gauge, 5/8-inch needle through the tendon and one of the proximal annular pulleys.

For tendons that are not locally accessible, I milk the tendon ends into the wound using a proximal-to-distal massage of the digit. The tendon is grasped directly on its cut end (the endotenon) with nontoothed forceps and is held in position using a 25-gauge needle. If the proximal tendon stump is not visible and cannot be delivered by milking into the wound, the wound is extended or a counterincision is made in the palm to retrieve the proximal tendon end. Repeated blind passes into the digital sheath using a hemostat or similar device in an attempt to grasp the tendon end can be associated with additional injury to the tendon sheath and should not be done. Because there is some evidence that epitendinous injury can be associated with peritendinous adhesion formation, I try to limit contact with the epitenon during tendon repair and grasp the tendon by the endotenon whenever possible.

Although there are several methods for acquisition of the proximal tendons, the method advocated by Sourmelis and McGrouther is reliable and effective. A small pediatric feeding tube or similar device is passed in a retrograde manner through the digital sheath. The tube should enter at the site of the laceration and exit in the palm proximal to the A1 pulley. The flexor tendons are left in situ in the sheath, and, through a midpalmar incision, the catheter is sutured to both tendons several centimeters proximal to the A1 pulley. The catheter is pulled distally, delivering the tendon stumps into the distal repair site easily. A 25-gauge, 5/8-inch needle is used to secure the tendons to adjacent soft tissues at the repair site. In situations in which the tendons have retracted proximal to the A1 pulley, an incision is made just proximal to the A1 pulley and the lacerated tendons and adjacent neurovascular structures are identified. The proximal stumps are delivered distally by the catheter method when possible. A Freer elevator or one of several commercial instruments may be used to “shoehorn” the tendon atraumatically into the flexor sheath beneath the A1 pulley.

It is crucial to reestablish the proper anatomic relationship of the FDS and FDP tendons in the palm and at the site of the repair. In some complex lacerations, orientation of the tendons and repair of all injured tendons may be impractical. In those cases, I resect one slip of the FDS tendon and repair one slip. This repair strategy facilitates gliding of the repairs within the sheath and simplifies tendon orientation.

If the tendon is lacerated proximal to the FDS decussation, a core suture is often used (see Figure 6.7 ). I base the core suture method on the caliber of the tendon that is available for repair. The more robust, thicker FDP tendon is ideal for core suture placement within zones 1 and 2. I prefer a 3-0 braided caprolactam looped (double-strand) suture affixed to a curved, tapered needle end. A four-strand modified Kessler core suture with locked loops offers a substantial improvement in time-zero repair site tensile strength and stiffness over traditional two-strand core suture techniques.

For smaller tendons, I use a four-strand modified Kessler suture that is placed with a 4-0 braided caprolactam looped suture. The suture may be placed simply in both ends and results in a strong four-strand repair. For larger tendons or where a stronger repair is desirable, I use two continuous modified Kessler sutures placed with a 3-0 looped suture made of braided caprolactam (eight strands). Using this method, the sutures lie side by side within the tendon. Because of the increase in suture volume, care must be taken to prevent impaling the transverse suture limb when passing the suture out of the cut end of the tendon. Locking loops of suture are not used. When using a single suture, the core suture is tensioned to bring the stumps together before beginning the second core component. When using looped suture, care must be taken to maintain even tension in all limbs of the suture; this allows the setting of an evenly tensioned suture knot. To finish the repair, a 6-0 polypropylene suture is used for a deep, running circumferential suture. This suture is started on a volar corner of the repair site and is placed circumferentially around the tendon over the repair site. When the stitch is started, I invert the first pass to facilitate inversion of the suture knot into the repair site. I leave one tail long when the suture is cut so that the running suture may be tied to itself when the suture is completed ( Figure 6.15 ).

Circumferential epitendinous suture techniques.

More distally, the FDS tendon repair is made difficult by the thin, flat shape of the tendon slips as they wrap around the FDP tendon. A traditional core suture may not be possible in the flattened FDS tendon slips near the PIP joint; these tendons may best be repaired using one of the zone 2 to 4 extensor tendon techniques. It is preferable to use a smaller needle along with a smaller-caliber suture to minimize tissue trauma. A 4-0 or 5-0 braided polyester suture affixed to a small, tapered needle at each end is effective.

After completion of all tendon sutures, I evaluate the stability of the repairs throughout a full range of digital motion and ensure satisfactory gliding of the repairs through the fibroosseous tunnel. Sheath closure is done only if it does not impair tendon gliding. These intraoperative observations may be valuable to clinicians in making decisions about aftercare regimens.

I prefer to repair the tendons first and then repair the injured nerves and arteries. Often the arterial repair is done last, with the tourniquet deflated using standard microsurgical dissection and repair methods. This also provides a satisfactory length of time for hemostasis to occur. Bipolar electrocautery is critical to prevent postoperative hematoma formation, and primary wound closure is performed in clean wounds using simple 5-0 nylon sutures. I believe that meticulous hemostasis limits postoperative swelling, diminishes postoperative pain, and facilitates rehabilitation.

A well-padded compressive, nonconstrictive dressing with a dorsal plaster slab is applied from the fingertips to the proximal forearm to hold the wrist, MP, PIP, and DIP joints in slight flexion to minimize passive myostatic tension on the repair site. All digits are included in the postoperative dressing. If the FPL tendon is repaired, the plaster splint overlies the dorsal aspect of the thumb to hold the carpometacarpal, MP, and interphalangeal (IP) joints in slight flexion.

Author’s Preferred Technique: Postoperative Rehabilitation of Repairs in Zones 1 and 2

Philosophically, I believe the tendon rehabilitation program has to be constructed to try to improve the function of the entire hand and facilitate differential incorporation of the injured soft tissues ( Figures 6.16 to 6.18 ). Generally, the method of rehabilitation is significantly influenced by the compliance of the patient, the nature of the wound, and the method and location of the repair. Although we still employ general time guidelines for implementation of various therapeutic interventions, we also accelerate and decelerate patients’ regimens based on their individual response to treatment. In this environment, there is no substitute for an experienced, energetic, meticulous hand therapist.

Controlled passive motion method. A, Orthoplast dorsal blocking splint is used to hold wrist in mild flexion, MP joints in about 45 degrees of flexion, and PIP and DIP joints in nearly full extension. B, Full isolated passive flexion of DIP joint. C, Full isolated passive flexion of PIP joint. D, Full passive flexion of MP, PIP, and DIP joints.

Controlled place-and-hold motion after flexor tendon repair protocol. A, After removal of the surgical bandage, a traditional dorsal blocking splint that positions the wrist in 20 degrees of palmar flexion, MP joints in 50 degrees of flexion, and IP joints in extension is applied. B, A tenodesis splint with a wrist hinge is fabricated to allow for full wrist flexion, wrist extension of 30 degrees, and maintenance of MP joint flexion of at least 60 degrees. C, After composite passive digital flexion, the wrist is extended and passive flexion is maintained. D, The patient actively maintains digital flexion and holds that position for about 5 seconds. Patients are instructed to use the lightest muscle power necessary to maintain digital flexion.

Clinical examples of the author’s program following flexor tendon repair. A, Index finger after a four-strand repair of FDS and FDP tendons. B, Resting splint with wrist and MP joints flexed and IP joints extended. C, Finger is passively flexed with the wrist in flexion. D, Wrist is extended while maintaining passive digital flexion. The patient holds this position with light active flexion. E, Extension at 3 years. F, Flexion at 3 years.

(Courtesy of James W. Strickland, MD.)

Therapists are encouraged to choose a postoperative program that controls the amount of force to the repair site, while promoting excursion of the tendon proximally and distally. Improvements in tendon excursion are thought to be associated with improvements in range of motion and patient outcome. The rationale for applying any force to the healing tendon during a postoperative rehabilitation program is to promote a small amount of proximal excursion and not to accelerate healing. Excessive force during rehabilitation can lead to tendon gapping or rupture. The force that is applied to the repair site is controlled during an aftercare program by exercise and the position of the wrist, MP, and IP joints.

Excursion, measured in millimeters, is best described as the total amount of glide that a point on the tendon travels during range of motion. In the original Duran and associates protocol, the authors reported that 3 to 5 mm of tendon excursion was sufficient to prevent restrictive adhesions after repair. This concept has been widely accepted and incorporated into tendon rehabilitation programs over the last 30 years. More recently, authors have concluded that 6 to 9 mm of excursion was the maximal limit of therapeutic excursion during a postoperative program, and that further excursion was not beneficial. Low force and moderate excursion programs have traditionally been effective and should continue to be effective in the future.

The first 4 weeks of therapy are the most important phase in the patient’s rehabilitation. Although each patient’s situation is generally similar, the particular therapy program must be individualized. Many factors influence decision making in the aftercare regimen, including patient compliance, edema (which increases the work of flexion), suture size and configuration, wound complications, tight wound dressings, systemic conditions, or concomitant injury. With these factors in mind, our center categorizes and treats postoperative patients in two general categories: patients who are appropriate for an accelerated rehabilitation program, and patients who are not. That decision is usually made with the input of the surgeon and the therapist.

Before beginning therapy, it is important for the therapist to have information from the operating surgeon about the type of repair that was done and whether other structures were injured. If a high-strength tendon repair technique was successfully performed in a compliant patient, the patient is placed in a more aggressive early motion program that employs individual decision making based on patient progress. Therapy typically begins 1 to 5 days after surgery. On the initial visit, a wrist-neutral dorsal blocking orthosis is applied. The MP joints are positioned at 50 degrees of flexion, a position that promotes gentle stretch on the collateral ligaments of the MP joints and prevents excessive stretch on the flexor tendons.

The patient is taught an hourly home exercise program that consists initially of passive positioning of the fingers in a fist for 3 minutes, with the splint in place. Next, within the confines of the orthosis, the patient performs the exercise of passive flexion of the affected finger to the palm, followed by actively extending the finger to the orthosis: 15 passive flexion and active extension movements to the bib of the splint are done in each hour. Finally, the patient removes the splint and performs a tenodesis program. The fingers are passively flexed into the palm using the unaffected hand, and the wrist is actively extended to a comfortable end range. The patient gently contracts the flexor muscles, removes the unaffected hand, and actively holds the fist position for 5 seconds. After 5 seconds, the patient releases wrist extension and the wrist falls into flexion, and as it does, the fingers passively extend. The tenodesis cycle is repeated 10 times.

When not exercising, the patient straps the fingers into the bib of the splint, positioning the MP joints in flexion and the IP joints at −10 to 0 degrees of extension. Based on the patient’s comfort with the program and any complicating factors, components of the program can be decelerated, accelerated, or discontinued by the therapist. The patient is counseled to stretch the PIP joint gently and passively with the MP joints held in flexion to avoid joint contracture. Wounds are dressed with loose-fitting 1/2-inch tube gauze. Edema is addressed in the first 2 weeks with elevation, the gentle pumping action of the exercises, and the gentle compression of the gauze. After 2 weeks postoperatively, compressive bandages can be applied as needed.

At 3 weeks postoperatively, the dorsal protective splint is removed for isolated and composite active joint range-of-motion exercises that are done hourly. The timing and type of active exercises prescribed at this point in the aftercare program are based on the physiologic healing response of the injured hand. Our decision to prescribe more forceful exercises has been adapted from the work of Groth, who analyzed and reported the results of differing wrist and hand positions coupled with passive and active movements to create a pyramid of progressive force application to the healing tendon. Groth defined “high” or “low” physiologic tissue responses and suggested clinical approaches to each. Accelerated wound healing, edema, and dense scar resulting in the formation of peritendinous adhesions characterize a “high” physiologic response. Ultimately with a “high” physiologic response, there is significant loss of flexor tendon excursion. Patients who exhibit a “high” response are progressed through the pyramid of exercises quickly to promote force and prevent further adhesions. During this time, the clinical evaluation for the formation of peritendinous adhesions that limit tendon excursion is done. The nonresistive exercises of the pyramid are ranked in ascending order of increased force, which includes place-and-hold, composite-fist, straight-fist, and isolated joint motion with joint blocking exercises.

Conversely, a “low” physiologic response is characterized by slower wound healing, limited edema, and minimal discrepancy between the patient’s active and passive finger flexion measurements. These patients generally have improved flexor tendon excursion, and less risk is required in therapy to maintain the range of motion. These patients may not have as robust a repair response, so progression to resistive exercises may be delayed, and patients are counseled not to use the hand in strength activities until cleared to do so by their surgeon.

The dorsal protective splint usually is discontinued at approximately 6 to 8 weeks postoperatively. If any flexion contractures of the IP joints are present, they are addressed with a static progressive device at that time. Isolated strength exercises are gradually introduced at 10 weeks postoperatively.

For more complicated cases, for patients with limited understanding, or for cases where compliance with the program is questionable, we use a passive mobilization program. The same dorsal protective splint is used, with the wrist in neutral and the MP joints in 50 degrees of flexion. A passive range-of-motion program (Duran type of program) of isolated IP and MP joint passive motion is taught. This program requires that the patient passively flex and extend the PIP joint of the affected finger while holding the DIP and MP joints flexed, and then passively move the DIP joint into extension and flexion with the MP and PIP joints flexed. All of the exercises are performed within the confines of the splint. The patient’s wounds and edema are addressed as described previously. The progression of force application after 4 weeks of passive motion is similar to that described previously, but delayed for 2 to 3 weeks.

When children or adolescents have sustained a lacerated tendon and subsequent repair, the surgeon must make a decision with help from the parents and treating therapist as to whether or not the patient is a candidate for an early motion program. A basic tenet of any early motion flexor tendon rehabilitation program is that the patient be an active participant in aftercare. For this reason, the surgeon, parents, and child all must agree that the child is mature enough to perform the essential functions of rehabilitation safely. If the decision is not to allow an early motion program, the patient’s wrist and hand are immobilized for 4 to 6 weeks in a cast positioning the wrist in neutral, the MP joints in 70 degrees of flexion, and the IP joints straight. After the initial period of immobilization, the patient is referred to therapy for careful initiation and progression of range-of-motion exercises for the next 6 weeks. Although the advantages of increased repair site tensile strength, decreased peritendinous adhesions, and better functional outcomes associated with early motion programs are well documented, immobilizing a child’s hand after flexor tendon repair has not been found to be as deleterious as it is for adults.

If participants agree that the patient is a candidate for an early protected range-of-motion program, the tenodesis aftercare program discussed previously is employed. The treating therapist must frequently monitor the patient’s compliance by having the patient attend therapy at least two times a week for the first 6 to 8 weeks. If more complicated forceful movements need to be eliminated from the child’s aftercare program, movements such as tenodesis with place-and-hold therapy or simply place-and-hold therapy alone can be reduced to passive flexion/active extension movements within the splint. Progression through the phase of therapy is done based on both the injury and the patient’s individual physiologic response to the injury.

Recent research has described the use of ibuprofen at antiinflammatory doses (2400 mg/day) to decrease peritendinous adhesions following zone 2 flexor tendon repairs. In their study, Rouhani and colleagues found that patients who received ibuprofen following tendon repair had a better range of motion compared with their control group. There were no reported complications.

Complications Following Flexor Tendon Repair

Despite continued improvement in surgical care and rehabilitation of flexor tendon injuries, complications still occur and may have devastating effects on hand function. Infection, skin flap necrosis, tendon repair rupture, and tendon adherence all adversely affect digital function after injury. The greatest protection against repair site rupture is a well-done multistrand core suture, complemented by a running circumferential repair, and early institution of high-quality hand therapy. Should rupture occur up to 3 weeks postoperatively, repeat repair is done. At time periods longer than 3 weeks postoperatively, the chance of a successful repeat repair is less likely. If rupture occurs, it is crucial that the condition be diagnosed and treated within days of the event, before scarring and retraction prevent successful repeat repair. Patients should be counseled regarding the possibility of tendon reconstruction with a silicone rod or tendon graft.

The repaired tendons may become adherent and fail to glide sufficiently to restore unimpeded digital function. The decision to proceed with tenolysis is made after serial joint measurements fail to show improved active digital motion despite continued therapy. A prerequisite for successful tenolysis is that full or nearly full passive digital flexion has been achieved. Tenolysis is a surgical strategy that should be considered 4 to 6 months after tendon repair for patients who have significant loss of tendon excursion.

Interphalangeal joint contracture can occur after flexor tendon repair, especially among patients treated with elastic traction. Early identification and treatment of the contracture usually result in satisfactory outcomes using nonsurgical strategies. Generally, these contractures can be resolved using passive stretching exercises and static progressive splints as needed. Patients with recalcitrant contractures that limit hand function at 4 to 6 months after tendon repair can be considered for small joint release.