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

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.