A 6-Year Follow-up of the Effect of Graft Site on Strength, Stability, Range of Motion, Function, and Joint Degeneration after Anterior Cruciate Ligament Reconstruction

BACKGROUND: The choice of graft material for anterior cruciate ligament reconstruction remains controversial. Despite the need for well-controlled, long-term outcome studies comparing patellar tendon with hamstring grafting, few studies have followed results for more than 5 years. HYPOTHESIS: Graft source will not affect outcome 6 years after reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Sixty-two patients with anterior cruciate ligament reconstruction and 18 uninjured control subjects were studied over 6 years. Thirty-one patients received patellar tendon grafts, and 31 received hamstring tendon grafts. Assessment included knee joint stability, range of motion, muscle strength, subjective function, objective function (running, sidestepping, carioca, and hop tests), and joint degeneration. RESULTS: Clinical stability was restored to all patients other than to the 2 hamstring graft recipients who suffered reinjuries. The KT-1000 arthrometer side-to-side differences were similar in the patellar tendon (1.9 mm) and hamstring tendon (2.0 mm) groups but were significantly greater than that of uninjured control subjects (P < .001). There were no significant strength differences between surgical and control groups, although a 6% quadriceps deficit existed after patellar tendon grafting. In the more demanding functional tests (hop and triple-hop indices and carioca), the hamstring graft recipients performed similarly to the control group, whereas a significant difference (P < .05) existed between the patellar tendon graft and the control group. The incidence of early tibiofemoral osteoarthritis was significantly greater after reconstruction using patellar tendon (62%) than after hamstring tendon grafting (33%; P = .002). CONCLUSION: Six-year outcomes were very satisfactory irrespective of graft source. However, reconstruction using the hamstring tendons resulted in improved functional performance and a lower incidence of osteoarthritis.