Hand surgeons from the University of North Carolina offer insight and ideas about flexor tendon repair. Despite improved surgical methods, problems after repair of tendon lacerations persist. The most common problems are scarring and joint contracture (loss of motion).
The authors say that understanding the basic science behind tendon healing is the first step toward improving results from hand surgery. They review the tendon anatomy in detail and review what’s needed for tendon healing.
The first week after a tendon injury, the body brings in healing cells to clean away any damaged or dead tissue. From weeks one to three new blood supply helps form new tissue. Then in the final (weeks three through eight), the new fibers line up along the tendon. It’s during this last remodeling phase that scar tissue called adhesions form between the tendon and its outer covering called the tendon sheath.
Motion, tension, and nutrition are the keys to tendon healing without adhesions. Tendon gliding is helped by the use of splints. Combining wrist and hand motion also helps improve overall tendon gliding inside the tendon sheath while producing low force on the repair site. Other ways to prevent scarring include careful surgical technique during tendon repair.
Scarless healing is the wave of the future. Scientists are looking into the use of polymer gels applied to the tendon after repair to limit adhesions. Growth factors used to enhance healing and inhibit scar formation are also being studied.
Problems can occur after tendon repair. The tendon may rupture, especially during the first 18 days if the patient does too much. Triggering can occur if the tendon repair is too tight or if scarring at the repair site catches as the tendon tries to glide. The authors review a wide range of other problems that can occur and the best known treatment for each one. Pulley failure and bowstringing, quadriga, swan-neck deformity, and lumbrical plus deformity are discussed.