The results of treatment for isolated zone 3 extensor tendon injuries

Objectives: We evaluated late-term results of surgical repair and physical rehabilitation of isolated zone 3 extensor tendon injuries. Methods: Sixteen patients (13 males, 3 females; mean age 28 years; range 11 to 57 years) underwent surgical repair for isolated simple central slip injuries of zone 3 extensor tendon. Injuries involved the second, third, fourth, and fifth fingers in seven, three, two, and four patients, respectively. Primary tendon repair was performed in 14 patients. Two patients were treated after one week and two months following primary injury, respectively. Tendons were repaired by modified Kessler and epitendinous sutures in four patients, and by locking running suture in 12 patients. Following surgical repair, three patients underwent K-wire fixation in extension for two weeks, while 13 patients received the short arc motion protocol. The patients were assessed with respect to proximal interphalangeal (PIP) joint motion and extension loss. Functional results were assessed using the Strickland formula. The mean follow-up was 58 months (range 8 to 120 months). Results: Full range of motion of the PIP joint was achieved in 15 patients (93.8%). The mean PIP joint motion was 98 degrees. One patient (6.3%) had an extension loss of 10 degrees in the range of motion of the PIP joint. There were no losses in the range of motion in three patients treated with K-wire fixation. The mean of the Strickland formula was 94.8% (range 74% to 100%), showing an excellent result in 15 patients (98.3%) and a good result in one patient (6.3%). All the patients returned to their pre-injury work status. None had buttonhole deformity or soft tissue complication. Conclusion: A proper suture technique combined with the short arc motion protocol provides good results in the treatment of isolated zone 3 extensor tendon injuries.