Regaining satisfactory digital function after flexor tendon laceration and repair within the digit has long been one of the most difficult problems in hand surgery. Until the 1960s it was universally recommended that tendons divided in the digit (then referred to as “no man’s land”) should not be repaired. Bunnell taught that “it is better to remove the tendons entirely from the finger and graft in new tendons smooth throughout its length.” That dictum remained sacrosanct until the 1960s when reports by Verdan, Kleinert et al, and Kessler and Nissim challenged the concept that flexor tendons should not be repaired primarily. These investigators noted that when done correctly, immediate tendon suture would outperform secondary free tendon grafting. Armed by those encouraging reports, there was a gradual and cautious development of the concept and practice of primary flexor tendon repair. Initially, primary tendon repair was often combined with anecdotal protocols by Duran et al, Lister et al, and Strickland and Glogovac for applying varying amounts of early post-repair motion to the repaired tendons. As often happens with advances in medicine, the efforts to improve the performance of flexor tendon repairs were based almost entirely on individual experience and clinical experimentation with little or no scientific support. The last 25 years, however, have heralded an enormous amount of basic research designed to improve our knowledge of the structure of tendons, including the kinesiology, the biomechanics of their action on the joints they move, their biologic response to injury and repair, the mechanical characteristics of various tendon suture constructs, and the effect of post-repair motion stress on tendon strength and healing. These investigative efforts have given rise to improved methods of tendon repair, a greater emphasis on flexor sheath preservation and restoration, and protocols for the early application of passive and active wrist and digital motion as a means to more rapidly increase the strength and gliding of repaired tendons. The following sections will provide a concise review of some of the most important of these reports.

Development of flexor tendon surgery: twenty-five years of progress.

In a prospective study, 114 patients with 138 zone 2 flexor tendon injuries were treated over a three-year period. Early active mobilisation of the injured fingers was commenced within 48 hours of surgery. 98 patients (86%) were reviewed at least six months after operation. Using the grading system recommended by the American Society for Surgery of the Hand, the active range of motion recovered was graded excellent or good in 77% of digits, fair in 14% and poor in 9%. Dehisence of the repair occurred in 11 digits (9.4%) and in these an immediate re-repair followed by a similar programme of early active mobilisation resulted in an excellent or good outcome in seven digits.

Early Active Mobilisation Following Flexor Tendon Repair in Zone 2

Most of the committee members agreed on the material presented Universal adoption of a single system for measuring and recording tendon function will require additional meetings It is suggested that TAM and the Dieter Buck-Gramcko systems be more widely publicized and adopted by various hand surgeons before further discussion

Report of the Committee on Tendon Injuries

The American academy of orthopaedic surgeons

Background: Elongation (gap formation) at the repair site has been associated with the formation of adhesions and a poor functional outcome after repair of flexor tendons. Our objectives were to evaluate the prevalence of gap formation in a clinically relevant canine model and to assess the effect of gap size on the range of motion of the digits and the mechanical properties of the tendons. Methods: We performed operative repairs after sharp transection of sixty-four flexor tendons in thirty-two adult dogs. Rehabilitation with passive motion was performed daily until the dogs were killed at ten, twenty-one, or forty-two days postoperatively. Eight tendons ruptured in vivo. In the fifty-six intact specimens, the change in the angles of the proximal and distal interphalangeal joints and the linear excursion of the flexor tendon were measured as a 1.5-newton force was applied to the tendon. The gap at the repair site was then measured, and the isolated tendons were tested to failure in tension. Results: Twenty-nine tendons had a gap of less than one millimeter, twelve had a gap of one to three millimeters, and fifteen had a gap of more than three millimeters. Neither the time after the repair nor the size of the gap was found to have a significant effect on motion parameters (p > 0.05); however, the ultimate force, repair-site rigidity, and repair-site strain at twenty newtons were significantly affected by these parameters (p < 0.05). Testing of the tendons with a gap of three millimeters or less revealed that, compared with the ten-day specimens, the forty-two-day specimens failed at a significantly (90 percent) higher force (p < 0.01) and had a significantly (320 percent) increased rigidity (p < 0.01) and a significantly (60 percent) decreased strain at twenty newtons (p < 0.05). In contrast, the tensile properties of the tendons that had a gap of more than three millimeters did not change significantly with time. Conclusions: Our data indicate that, in a dog model involving sharp transection followed by repair, a gap at the repair site of more than three millimeters does not increase the prevalence of adhesions or impair the range of motion but does prevent the accrual of strength and stiffness that normally occurs with time. Clinical Relevance: Tendons that have a large gap are at increased risk for rupture during early rehabilitation, and this risk of rupture does not decrease in the first six weeks.

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.

In an effort to overcome restrictive adhesions following flexor tendon repair, a technique involving beveling of the tendon ends and fine compressive suturing was used in 50 patients (110 tendons). Free early active motion was allowed. There were 70% good-to-excellent results, with a 10% rupture rate.

Early active motion following a beveled technique of flexor tendon repair: report on fifty cases.

Summary A new approach to the problem of flexor tendon repair within the fibro-osseous canal is presented. Using a technique of bevelling the tendon ends and suturing with a fine suture material, under magnification, a sufficiently strong junction is obtained, which enables immediate active mobilisation without strangulation of the blood supply. The junction can resist gap formation up to tensions of 4 Kg. It is postulated that under these conditions tendon nutrition is minimally interfered with, adhesions do not form, and the tendon heals by its own intrinsic healing ability.

Primary repair of flexor tendons in the hand without immobilisation — Preliminary report

A new method of tendon suture has been designed to eliminate the development of a gap when tension is applied to the repair. It has been demonstrated to resist distraction at relatively high tensions on cadaveric tendon. The possible advantages of the technique are discussed.

Eliminating the gap in flexor tendon surgery. A new method of suture.

The versatile costal osteochondral graft in nasal reconstruction

Two cases of fibromatosis of the upper limb are presented, neither of which could be placed in a specific category as described in the literature. Both patients were black, and both had a history of previous trauma to the region, which has been regarded as an initiating factor. Emphasis is placed on conservative treatment in order to maintain hand function as long as possible.

Hilton Becker

Papers

Early active motion following a beveled technique of flexor tendon repair: report on fifty cases.

Primary repair of flexor tendons in the hand without immobilisation — Preliminary report

Eliminating the gap in flexor tendon surgery. A new method of suture.

The versatile costal osteochondral graft in nasal reconstruction

Fibromatosis of the upper limb.