AUTHOR AND EDITOR INFORMATION

Section 1 of 8  

• Authors and Editors
• Introduction
• Relevant Anatomy
• Contraindications
• Treatment
• Complications
• Outcome and Prognosis
• References

INTRODUCTION

Section 2 of 8  

• Authors and Editors
• Introduction
• Relevant Anatomy
• Contraindications
• Treatment
• Complications
• Outcome and Prognosis
• References

Tendon nutrition

The tendon derives its nutrition from the following 2 sources:

• Diffusion, via the synovial lining sheath

  Canaliculi pass through the tendon to the surface of the tendon. Movement of fluid into these canaliculi has been demonstrated. This effect is enhanced with digital motion.

• Perfusion, via the segmental arterial supply

  The blood supply to the tendon enters distally via the bony insertion and proximally via the vincula. Four vincula, designated V1 to V4, are present. V1 and V2 supply the flexor digitorum superficialis, and V3 and V4 supply the flexor digitorum profundus. They arise at the necks of the proximal and distal phalanges, respectively. In the thumb, the vincula likewise are termed V1 and V2. No flow occurs between adjacent territories of vincula. Presumably, this area is sustained by diffusion through the synovial fluid. The vascular plexus within the tendon occupies the dorsal half. This is important at the time of placement of core sutures during flexor tendon repair.

Logically, diffusion occurs in areas of the tendon that are compressed in flexion, while the other areas are perfused. The flexor digitorum profundus is more dependent on diffusion than the flexor digitorum superficialis.

Tendon healing

A debate persists as to the nature of tendon healing.

• Extrinsic: The original theory was that sheath fibroblasts were responsible for peritendinous adhesions, and the tendons were healed by this route. This was the theory behind total flexor sheath excision and prolonged immobilization for tendon repairs.
• Intrinsic: Tendons bathed in synovial fluid were found to heal satisfactorily. The necessary collagen was produced by the tenocytes.

Modern thinking is that tendon healing is initiated by the proliferation of epitendinous cells, which migrate into the defect, forming a "callus" equivalent. Somewhat later, the tenocytes or fibroblasts from within the tendon invade the callus, producing further collagen that realigns to produce the strong tendon. Peritendinous adhesions are not necessary for either healing or nutrition.

RELEVANT ANATOMY

Section 3 of 8  

• Authors and Editors
• Introduction
• Relevant Anatomy
• Contraindications
• Treatment
• Complications
• Outcome and Prognosis
• References

Fibrous flexor sheath

Roughly half of all flexor tendon injuries occur in zone II. The sheath commences at the palmar plate of the metatarsophalangeal (MP) joint with the A1 pulley. A condensation of the palmar aponeurosis results in the so-called palmar aponeurosis (PA) pulley. Where the tendon overlies a joint, the sheath should be sufficiently thin and resilient, resulting in the cruciate (or retinacular) intervals. Where the flexor sheath overlies the phalanges, it is tough and unyielding (annular pulleys A2 and A4). Additional annular pulleys overlie the palmar plates of the MP, proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints, respectively (A1, A3, A5 pulleys). These are continuous with the transverse retinacular ligaments dorsally.

In the thumb, A1 and A2 pulleys are over the palmar plates, and an oblique pulley is over the proximal phalanx. This passes from proximal ulnar to distal radial; in so doing it is virtually an extension of the adductor, which inserts into the sesamoids. The sesamoids, into which insert the 2 heads of flexor pollicis brevis (FPB), lie within the substance of the palmar plate.

In the thumb, similar to the A2 and A4 pulleys in the fingers, the oblique pulley is sacrosanct. Because of the obliquity of the oblique ligament and ulnar takeoff, the A1 pulley in the thumb is best divided radially. This is important when surgical release of a trigger thumb is performed. No pulley should be incised during the course of tendon repair, with exception of the A1, A3, and A5 pulleys. Repair is impossible due to the snug fit and the transverse orientation of the fibers.

Tendon sheath and pulley reconstruction

The issue of sheath reconstruction is controversial, and the decision to undertake this is best individualized after thorough assessment of the patient. The sources of fascia include the adjacent fingers, the dorsal wrist retinaculum, and the foot. For pulley reconstruction, place the tendon graft around the phalanx (sutured to itself), either beneath the extensor tendon for the A2 pulley or superficial to it for A4 pulley reconstruction. A transverse strip of dorsal wrist retinaculum is harvested via a longitudinal incision. If performing a Hunter rod reconstruction, reconstructing the pulley first is often useful before placing the rod to achieve sufficient tension on the pulley. Following suture of the graft, it is rotated around so that a synovial surface overlies the tendon. Such grafts have been demonstrated to continue secreting synovial fluid.

CONTRAINDICATIONS

Section 4 of 8  

• Authors and Editors
• Introduction
• Relevant Anatomy
• Contraindications
• Treatment
• Complications
• Outcome and Prognosis
• References

Procedures that involve extension of the tendon are contraindicated for 2 reasons: firstly, the quadriga effect on the other digits is invoked, and secondly, an extension deficit of the involved digit is always present.

Contraindications to 1-stage tendon grafting include less than full ROM, inadequate skin cover, and a hostile bed.

TREATMENT

Section 5 of 8  

• Authors and Editors
• Introduction
• Relevant Anatomy
• Contraindications
• Treatment
• Complications
• Outcome and Prognosis
• References

Surgical Therapy

Incisions

The objectives are to maintain the blood supply as completely as possible, obtain adequate exposure, and obtain optimal scar contracture. Bunnell developed the midlateral incision as the stationary line, either volar or dorsal to the neurovascular bundle. Littler demonstrated the diamonds of skin-to-skin contact during digital flexion. The Bruner zigzag incision avoids these areas. Preservation of the vincula is difficult if the dorsal midlateral incision is used, and hence either the Bruner or the volar midlateral incision is recommended. Midlateral incisions should not be made on surfaces exposed to much contact (eg, ulnar border of little finger, radial border of index finger). The distal extent of either incision is over the pulp of the phalanx.

Primary repair

Clinical clues to flexor tendon injury include loss of the normal digital cascade and the tenodesis effect observed with wrist motion. In lacerations of the flexor digitorum profundus alone, the DIP joint may be held in flexion by the intact short vinculum. Isolated flexor digitorum superficialis injury results in no overt postural deficit.

The retinacular portion of the sheath is elevated as an L-shaped flap, allowing a 2-mm cuff of tissue for subsequent repair. Furthermore, this L should be orientated such that a tendon end can be funneled into it. Flexion of the wrist is a useful intraoperative ploy that facilitates mobilization of the proximal tendon stump. Often the proximal tendon stump is hidden by a hematoma within the tendon sheath. The chiasm of Camper (flexor digitorum superficialis decussation that lies opposite the proximal digital flexion crease) is a useful anatomic marker for tendon repair within zone II.

Remember that distal to the mid point of the proximal phalanx, the deep tendon is the flexor digitorum superficialis, and the superficial is the flexor digitorum profundus. Prior to commencing the repair, it is vital that no tension is across the tendon ends. The technique of repair is based on the length of distal tendon. Two groups of core suture exist: (1) those that criss-cross the tendon (Bunnell) and (2) those in which the suture lies parallel to the tendon fibers (Kessler, Tajima).

Urbaniak et al demonstrated that the former group of sutures tends to strangulate the tendon ends, with a net reduction in tensile strength. The epitenon must never be handled so that damage that predisposes to peritendinous adhesions is minimized. Terminal damage to the epitenon also jeopardizes the quality of subsequent peripheral suture. The tendon end can be grasped lightly with a toothed forceps. A 4/0 material is used for the core suture. Importantly, the first pass of the needle must be parallel to the tendon fibers. The length of bite is approximately 1 cm, with the transverse limb of the suture passing superficial to the longitudinal limbs. The core suture should not pull the tendon ends together. This is the value of overlapping the ends with transfixion needles. Employ at least 4 throws of the knot, with the ends cut at 2 mm. The protruding suture ends so as not to jeopardize subsequent healing or function. Knot slippage is said to occur in as many as 40% of repairs.

The suture material for the peripheral running suture should be 2 gauges lighter than the core suture (6/0 nylon for adults). Like the core suture, it may be either monofilament or braided material. Monofilament material generally is preferred for both sutures. The first pass of the peripheral suture should be performed in a figure-of-eight fashion to avoid cutting out. Most importantly, it should engage only the epitenon. A shallow inverting suture is ideal, thus burying the repair. A Lembert suture can be employed if necessary. The passage of this needle should meet minimal resistance if in the correct plane. Following tendon repair, little or no bulk should be found in the tendon ends.

The general recommendation is that both flexor digitorum superficialis and flexor digitorum profundus should be sutured, even in zone II. Lister recommends the use of 2 core sutures for the flat tendon of flexor digitorum superficialis. A divided flexor digitorum superficialis derotates through 90°. The management of partial lacerations is controversial.

Following the report by Weeks and Wray that partial lacerations should be managed conservatively, Kleinert et al found that failure to repair these results in triggering and delayed rupture. Current recommendations for partial tendon injuries are presented in the following table.

Table 1. Current Recommendations for Partial Tendon Injuries

Recent debate centers on the benefit of multistrand repairs and whether a multistrand repair confers greater early tensile strength and, therefore, rapid rehabilitation over the conventional-type repair. Recent biomechanical and histological data show no differences between two-strand and four-strand repairs. The use of an epitendinous suture gives similar results. If care is taken with the surgical technique, adhesion formation is not necessarily increased by the use of multistrand techniques or by the placement of an epitendinous suture. More variability is introduced by individual healing response than by an increase in tendon handling by an experienced surgeon (Strick, 2005).

Resistance to failure in different repair techniques varies according to the number of locking junctions with the tendon, location, and orientation of the sutures. These factors influence the resistance to failure independent of the number of sutures used (Xie, 2002).

Recent experimental evidence in both the canine model and clinical studies suggests a stainless steel device (Teno Fix) may be promising for zone II flexor tendon repairs (Su, 2006).

The history of flexor tendon repair has been described well by Dr. Paul Manske (2005).

Distal flexor digitorum profundus stump

• The distal flexor digitorum profundus stump usually can be involved in a formal suture repair if longer than 1 cm.
• The proximal core suture can be inserted into the distal stump if shorter than this and brought out through 2 20-gauge needles inserted through the distal pulp, 3 mm volar to the nail.
• If no distal stump is present, it should be brought out through the distal phalanx and sutured over a button on the nail.

Procedures that involve extension of the tendon are contraindicated for 2 reasons: firstly, the quadriga effect on the other digits is invoked, and secondly, an extension deficit of the involved digit is always present. At most, the flexor digitorum profundus can be advanced by 1 cm.

Avulsion of the profundus

This is a common "rugby jersey" injury. It is most common in the ring finger. Three types are described in Table 2.

Table 2. Three Types of Avulsion of the Profundus

When reinsertion is possible, it should be performed as above, taking the sutures out through the pulp. If this is not possible, then either perform arthrodesis on the DIP joint or consider flexor tendon reconstruction.

Tendon repair out of zone II

The epitenon is not as well defined, and the peripheral running suture is unnecessary. The objective in these situations is strength of closure rather than finesse. If the deep carpal ligament needs to be divided, the wrist should be splinted in slight dorsiflexion. Alternately, the latter may be repaired. In repairs at the wrist, the best initial maneuver is to excise the glutinous mass of synovium by means of a thorough synovectomy. The distal ends easily are identified by their actions. Caution should be exercised in grasping the cut ends of the tendon (grasp only the cut surface and not the epitenon). The clues to identification of the proximal ends are as follows:

• Matching the cross-sectional areas
• Matching the angle of laceration
• Matching the anatomic layers
• • Superficial flexor digitorum superficialis to middle and ring fingers
  • Middle flexor digitorum superficialis to index and little fingers
  • Deep all flexor digitorum profundus (index finger separate)
• Matching the length to achieve the normal position in repose

Injuries at the musculotendinous junction should be repaired whenever possible. A figure-of-eight suture with 2 unequal loops is best.

Untidy injuries

In oblique injuries, when the injury is clean, no reason exists to render the cut transverse. Judging the correct tension in the core suture is more difficult, and this may be left untied until the peripheral suture is completed partially. Ragged ends should be resected. The tendon can be held with umbilical tape and resected with a razor blade. Double level repairs do not present a problem if more than 3 cm apart. If closer, a single core suture should be used.

Postoperative management

"A moderate amount of intermittent movement, with as long an excursion as possible, interspersed by rest, will yield the best results" (Stirling Bunnell).

The tourniquet should be released after closure of the sheath to achieve hemostasis.

Mason demonstrated that a healing tendon has minimal tensile strength until it is stressed. Immediate mobilization of the flexor tendon repair has been demonstrated to reduce peritendinous adhesions and increase tensile strength, DNA content, eventual excursion, and uptake of synovial fluid. The options are (1) controlled passive motion, (2) active extension and rubber band flexion, and (3) immediate active motion with limited extension.

The rehabilitation protocol must be modified to the individual patient in question. The clinician should approach each patient individually and progress them with a personalized and tailored approach in close communication with the surgeon and therapist. Functional hand motion and strength are the end results of successful flexor tendon surgery and rehabilitation (Vucekovich, 2005).

Controlled passive motion (Duran and Houser technique)

In this technique, a dorsal block splint is used (similar position to the Kleinert splint), and the fingers are immobilized in Velcro straps. The joints are flexed passively 3 times per day. This often is used in children younger than 6 years; an above-elbow cast is applied with the wrist neutral, the MP joints at 900, and the interphalangeal (IP) joints in full extension.

Active extension and rubber band flexion (Kleinert technique)

The wrist is immobilized 20° short of full flexion, and the MP joints are in 45° flexion. Only the involved finger is incorporated in the rubber band. Free mobility of the other fingers encourages extension of the involved finger. In children older than 6 years, the Kleinert cowl splint is used, but the rubber band is not attached until the child fully understands the technique. Bear in mind that attaching the rubber band in a patient unaware if its significance renders the patient at high risk of a flexion contracture; therefore, great responsibility is associated with the use of the Kleinert band. The Kleinert-Breidenbach splint incorporates a spring-loaded roller bar in the mid palm.

Electromyographic studies since have shown that little flexor inhibition may be present during the extension phase and that opposition to extension serves little purpose. Therefore, the band only should be sufficiently taut so as to flex the finger. For each 100 of flexion at the DIP joint, the flexor digitorum profundus only moves 1 mm. Although passive motion moves joints, whether passive mobilization moves tendons is unknown. The only known way of moving tendons sufficient to prevent adhesions is by active mobilization. Recent modifications of the original Kleinert technique flex the wrist less and the MP joints more.

Immediate active motion with limited extension

More recent reports have advocated this technique and have demonstrated good results. However, the risk of tendon rupture is inevitably greater. Table 3 provides a summary.

Table 3. Summary of Modifications of Immediate Active Motion With Limited Extension

Patients should be observed at least twice weekly by the surgeon and more frequently by the therapist.

If the active range of motion (AROM) is full after 4 weeks, the splint may be removed and the elastic band attached to a wrist strap for a further 2-3 weeks. If the band is discarded at this time, risk of rupture is significant. Bear in mind that the patient who is mobilizing best is at greatest risk of rupture. In these patients, the rehabilitation process should be retarded.

If AROM is poor after 4 weeks, the patient is at risk of a flexion contracture. The band is discarded, and physiology becomes more active. Warn the patient about the risk of rupture. Dynamic splintage can be employed after 8 weeks without risk of rupture.

Secondary reconstruction

Factors dictating the success of tendon reconstruction include the following:

• Age: Very young and elderly patients do not fare as well.
• Occupation: Often those with busy lifestyles cannot afford the time to spend at rehabilitation.
• Mechanism of injury: The more widespread the zone of initial injury, the greater the scarring is likely to be. The amount of scarring is inversely proportional to the range of motion (ROM) subsequently achieved.
• Quality of initial care
• Previous operations: The likelihood of success lessens as the number of procedures that have preceded the proposed operation increases.

Defer performing the procedure on the patient until the skin is mobile, the joints are supple, scars mature, adequate perfusion to the digit is present, adequate sensation exists, and a stable skeleton is present. Limitation in ROM may be due to skin, sheath, or tendon on either side of the digit or the palmar plate. In pure flexor tendon adhesions, passive flexion exceeds active flexion. If extensor tendon adhesions are present, perform tenolysis on these prior to contemplating flexor tendon reconstruction. A useful approach is to examine all other structures first, leaving the flexor tendon until last.

The DIP joint contributes only 3% to the overall total arc of motion of the digit. By contrast, the PIP joint contributes 20% of the total arc. Jeopardizing the function of the PIP joint by tendon grafting may not have a favorable risk-to-benefit ratio. Instead, the flexor digitorum superficialis stump may undergo tenolysis to the middle phalanx, or arthrodesis can be performed on the DIP joint. McClinton et al reported a 13% failure rate in flexor digitorum profundus reconstruction. Therefore, the question remains as to whether benefit is found in delayed flexor digitorum profundus reconstruction, with a possible gain of 3% total arc of motion. The risk-to-reward ratio is most favorable in carefully selected, young patients in whom arthrodesis may result in growth disturbance.

Flexion contracture

The causes of flexion contracture are poor rehabilitation, bowstringing of tendons, poor splintage, and failure to create an effective repair. The severity of the contracture is measured by the extension deficit. Bowstringing tendons require additional length to achieve the same degree of flexion. This excursion is not available. The diagnosis is made by asking the patient to flex against resistance.

Tenolysis or exploration

Tenolysis usually is indicated when passive range exceeds active range and all joints have full ROM. No optimal time exists at which to perform tenolysis. It should be performed when the following are met:

• Soft tissue scars are mature.
• The benefit from therapy has reached a plateau.

Local anesthesia is best, since it allows the patient to participate in the operation and to visualize the intraoperative gains. A forearm tourniquet may be useful. Immediate mobilization follows surgical release. In patients not operated on under local anesthesia, immobilize the digit in flexion, since clot adhesions can be broken more easily by extension than by flexion. Prolonged postoperative anesthesia is optimal. The tendons are identified both distally and proximally in the palm. Dissection continues from either side to the point of fusion or adhesion to surrounding structures. Take care not to damage the epitenon, since this invariably leads to tendon adhesions at this point. Assess the completeness of tenolysis by the following:

• Marking the tendon with ink
• Observing ROM resulting from tendon excursion (limitation is due either to adhesions or inadequate pulleys)
• Checking the proximal extent of the tendon as far as the musculotendinous junction (this is best performed by asking the patient to demonstrate ROM)

On completion, the tendon may be excessively long or tenuous or the pulley system may be inadequate. If the tendon is very tenuous, placing a rod alongside it may be worthwhile. If the tendon ruptures, a tendon rod is already in situ. Additional procedures include capsulotomy and skin coverage with a flap. The perfusion of the digit may be poor in the extended position, necessitating a vein graft.

Local administration of corticosteroids may lead to increased rupture, attenuation, and infection. Systemic administration is controversial. Interpositional materials generally are not used.

Postoperative mobilization should be unresisted active exercise. Caution should be exercised regarding the possibility of rupture with unprotected extension. An extensor splint may be necessary for recurrent flexion contracture. However, the risk of rupture is increased by the use of such a splint.

Tendon grafting

Contraindications to 1-stage tendon grafting include less than full ROM, inadequate skin cover, and a hostile bed. Donor options are the palmaris longus, extensor digiti quinti, and plantaris tendons. Alternately, the extensor digitorum to the index finger or the extensor digitorum longus to the second, third, or fourth toes may be used. The distal insertion is through, around, or along the distal phalanx. Lister prefers the latter, as the former two carry some risk of damage to the nail bed. If the flexor digitorum profundus is divided distal to the lumbrical origin, little, if any, myostatic contraction occurs. Pulling the proximal tendon out to length is important to achieve the benefit of creep. The active excursion varies for each muscle, but generally it is approximately double the passive excursion achieved on the operating table. For tendons of unequal dimension, a Pulvertaft weave is preferred for the proximal tenorrhaphy. Three slots, each at 900 to each other, are used.

Two-stage reconstruction

Two-stage reconstruction is indicated when the digit is not suitable for a 1-stage graft due to the following:

• Skeletal instability
• Joint requiring capsulectomy
• Inadequate skin coverage
• Pulleys requiring reconstruction
• Scarred graft bed

Scarred graft bed is the most common indication. Some digits may be insensate, have severe flexion contractures, or occur in an uncooperative patient; in these situations, the patients are not candidates for reconstruction.

The decision to proceed with 2-stage reconstruction usually is made after failed tenolysis. Resect the flexor digitorum profundus, leaving the distal 1 cm, back to a point 2 cm distal to the lumbrical origin. Preserve the flexor digitorum superficialis from the proximal end of the chiasm of Camper distally to prevent recurvatum deformity of the PIP joint. The Hunter silicone rod or the Holter-Hauser rod may be used. The Holter-Hauser rod has a screw fixation device distally. A 4-mm rod usually is selected for adults. The proximal end of the rod is brought out proximal to the wrist crease. Complications include synovitis (15-20%), migration, extrusion, flexion contracture, and buckling of the rod. Hunter found no propensity for longitudinal contracture in the primate model. The final outcome is better when wounds are left to mature for a longer time.

Intraoperative Details

Sheath closure

Repair of the sheath is highly recommended. This usually is performed with a continuous 6/0 nylon suture. Make sure by flexing the finger that the sutures are not tethering the epitenon. Overtight closure may impede the passage of an edematous tendon. Interestingly, the best results reported were in a series in which the sheath was not closed (Chow, 1988). Strauch and others advocate the use of autogenous vein patches for sheath closure. Closure of the sheath prior to extension of the digit after tendon repair facilitates delivery of the repair beneath the A3 pulley.

COMPLICATIONS

Section 6 of 8  

• Authors and Editors
• Introduction
• Relevant Anatomy
• Contraindications
• Treatment
• Complications
• Outcome and Prognosis
• References

Complications of tendon grafting

Most common complications of tendon grafting include rupture, adhesion, flexion contracture, recurvatum deformity (swan neck), bowstringing, lumbrical plus, and quadriga syndrome.

The rupture rate after tenolysis is high (21% in Lister's series). This is most commonly at the proximal repair site.

The swan neck deformity results from excision of the flexor digitorum superficialis. It can be prevented by retaining the part of the flexor digitorum superficialis to which the V2 vinculum attaches. It is corrected by either capsulodesis or by the construction of a spiral oblique retinacular ligament.

Lumbrical plus occurs when the graft is too long and the tension then is taken up by the lumbrical insertion, resulting in paradoxical extension of the IP joints with forced flexion. The division of the lumbrical corrects this complication. Because the grafted finger reaches the palm prior to the other fingers, this places a block on further flexion of the other fingers (the quadriga syndrome).

OUTCOME AND PROGNOSIS

Section 7 of 8  

• Authors and Editors
• Introduction
• Relevant Anatomy
• Contraindications
• Treatment
• Complications
• Outcome and Prognosis
• References

Reporting results

Various methods of expressing the results of tendon repair or grafting are as follows:

• Littler method: Each joint's individual ROM is measured.
• Boyes technique: This technique uses the pulp-to-midpalmar crease measurement (nail-to-table measurement can be added).
• Total active motion (TAM): This incorporates the summed ROM of the IP joints less the extension deficit, as a fraction of 175 (Strickland, 1995). Others incorporate MP measurement.
  
  Strickland reported 50% of repairs achieved 50% of TAM. He reported 80% improvement following tenolysis, with 3% rate of rupture. Lister reports 71% improvement but with 21% rupture.
• TAM-to-total passive motion (TPM) ratio: This is the postoperative TAM2 as compared to the preoperative TPM1 for tendon grafts. In flexor tendon repair, the postoperative TAM2/175 is used.
  
  Lister believes this to be the best method for reporting results. He reports 76% TAM/TPM for grafts.
  
  Strickland's formulae are as follows:
• • Flexor tendon repair - TAM2/175 as a percentage
  • Tendon grafting - TAM2/TPM1 as a percentage
  • Tenolysis - 100 - TPM1-TAM2/TPM1-TAM1 as a percentage
• Lister technique and the Buck-Gramko technique: Both incorporate the TAM (with MP) and distance from pulp to midpalmar crease. These are used widely.

Results

Lister reports 80% good or excellent results in zone II with 85% outside of zone II. The flexor digitorum superficialis was excised in only 25% of patients with zone II injuries, and in these patients only 45% achieved good or excellent results. This result is difficult to explain, but it may reflect improved blood supply or greater strength with the intact flexor digitorum superficialis. Only 12% of patients required tenolysis. Singer and Maloon report 80% excellent or good results.

REFERENCES

Section 8 of 8

• Authors and Editors
• Introduction
• Relevant Anatomy
• Contraindications
• Treatment
• Complications
• Outcome and Prognosis
• References

• Aslam A, Afoke A. A new core suture technique for flexor tendon repair: biomechanical analysis of tensile strength and gap formation. J Hand Surg [Br]. Aug 2000;25(4):390-2. [Medline].
• Barrie KA, Wolfe SW, Shean C, et al. A biomechanical comparison of multistrand flexor tendon repairs using an in situ testing model. J Hand Surg [Am]. May 2000;25(3):499-506. [Medline].
• Bunker TD, Potter B, Barton NJ. Continuous passive motion following flexor tendon repair. J Hand Surg [Br]. Nov 1989;14(4):406-11. [Medline].
• Cerovac S, Afoke A, Akali A, McGrouther DA. Early breaking strength of repaired flexor tendon treated with 5- fluorouracil. J Hand Surg [Br]. Jun 2001;26(3):220-3. [Medline].
• Chow JA, Thomes LJ, Dovelle S, et al. Controlled motion rehabilitation after flexor tendon repair and grafting. A multi-centre study. J Bone Joint Surg Br. Aug 1988;70(4):591-5. [Medline].
• Gelberman RH, Manske PR, Akeson WH, et al. Flexor tendon repair. J Orthop Res. 1986;4(1):119-28. [Medline].
• Grobbelaar AO, Hudson DA. Flexor tendon injuries in children. J Hand Surg [Br]. Dec 1994;19(6):696-8. [Medline].
• Kleinert HE, Lubahn JD. Current state of flexor tendon surgery. Ann Chir Main. 1984;3(1):7-17. [Medline].
• Kleinert HE, Spokevicius S, Papas NH. History of flexor tendon repair. J Hand Surg [Am]. May 1995;20(3 Pt 2):S46-52. [Medline].
• Manske PR. Flexor tendon healing. J Hand Surg [Br]. Aug 1988;13(3):237-45. [Medline].
• Manske PR. History of flexor tendon repair. Hand Clin. May 2005;21(2):123-7. [Medline].
• May EJ, Silfverskiold KL, Sollerman CJ. Controlled mobilization after flexor tendon repair in zone II: a prospective comparison of three methods. J Hand Surg [Am]. Sep 1992;17(5):942-52. [Medline].
• Norris SR, Ellis FD, Chen MI, Seiler JG 3rd. Flexor tendon suture methods: a quantitative analysis of suture material within the repair site. Orthopedics. Apr 1999;22(4):413-6. [Medline].
• Silfverskiold KL, May EJ, Tornvall AH. Flexor digitorum profundus tendon excursions during controlled motion after flexor tendon repair in zone II: a prospective clinical study. J Hand Surg [Am]. Jan 1992;17(1):122-31. [Medline].
• Singer M, Maloon S. Flexor tendon injuries: the results of primary repair. J Hand Surg [Br]. Aug 1988;13(3):269-72. [Medline].
• Slattery PG. The modified Kleinert splint in zone II flexor tendon injuries. J Hand Surg [Br]. Aug 1988;13(3):273-6. [Medline].
• Small JO, Brennen MD, Colville J. Early active mobilisation following flexor tendon repair in zone 2. J Hand Surg [Br]. Nov 1989;14(4):383-91. [Medline].
• Strick MJ, Filan SL, Hile M. Adhesion formation after flexor tendon repair: comparison of two- and four-strand repair without epitendinous suture. Hand Surg. Dec 2005;10(2-3):193-7. [Medline].
• Strickland JW. Flexor tendon injuries. Part 5. Flexor tenolysis, rehabilitation and results. Orthop Rev. Mar 1987;16(3):137-53. [Medline].
• Strickland JW. Flexor Tendon Injuries: II. Operative Technique. J Am Acad Orthop Surg. Jan 1995;3(1):55-62. [Medline].
• Strickland JW. Flexor Tendon Injuries: I. Foundations of Treatment. J Am Acad Orthop Surg. Jan 1995;3(1):44-54. [Medline].
• Su BW, Solomons M, Barrow A. A device for zone-II flexor tendon repair. Surgical technique. J Bone Joint Surg Am. Mar 2006;88 Suppl 1 Pt 1:37-49. [Medline].
• Su BW, Solomons M, Barrow A. Device for zone-II flexor tendon repair. A multicenter, randomized, blinded, clinical trial. J Bone Joint Surg Am. May 2005;87(5):923-35. [Medline].
• Tang JB, Wang B, Chen F, et al. Biomechanical evaluation of flexor tendon repair techniques. Clin Orthop. May 2001;(386):252-9. [Medline].
• Tang JB, Gu YT, Rice K, et al. Evaluation of four methods of flexor tendon repair for postoperative active mobilization. Plast Reconstr Surg. Mar 2001;107(3):742-9. [Medline].
• Vucekovich K, Gallardo G, Fiala K. Rehabilitation after flexor tendon repair, reconstruction, and tenolysis. Hand Clin. May 2005;21(2):257-65. [Medline].
• Xie RG, Zhang S, Tang JB. Biomechanical studies of 3 different 6-strand flexor tendon repair techniques. J Hand Surg [Am]. Jul 2002;27(4):621-7. [Medline].

Article Last Updated: Jun 8, 2006