Primary versus single-stage revision anterior cruciate ligament reconstruction using autologous hamstring tendon grafts: a prospective matched-group analysis.

BACKGROUND: There is a low level of evidence about clinical results after anterior cruciate ligament (ACL) revision reconstruction using autologous hamstring tendon grafts.

HYPOTHESIS: Anterior cruciate ligament revision reconstruction improves knee stability but shows inferior results for functional and subjective outcome and knee stability compared with primary reconstruction.

STUDY DESIGN: Cohort study; Level of evidence, 2.

METHODS: Between October 1997 and July 2005, 166 single-stage or 2-stage revision ACL reconstructions were done using different graft types. One hundred twenty-four cases underwent a single-stage revision reconstruction with autologous hamstring tendon grafts. At the time of data analysis, 67 cases fulfilled the criteria of minimum 2-year follow-up. Five patients were lost to follow-up (follow-up rate, 91%). Four patients (6%) who experienced graft rupture were counted as failures but not subjected to further detailed analysis. Because of loss to follow-up and exclusion criteria (n = 12), 50 patients were included in the study. For a comparative matched-group analysis, patients with a primary hamstring tendon graft ACL reconstruction were selected out of a database with minimum 2 years' follow-up (N = 284). Patients were followed using the International Knee Documentation Committee (IKDC) and Lysholm scores, KT-1000 arthrometer testing, and additional functional tests.

RESULTS: Four of 62 available patients (6.5%) in the revision group experienced graft failure, which was comparable to 16 of 284 (5.6%) in the primary reconstruction group. When the 2 matched groups of 50 patients were further compared, postoperative IKDC results showed no significant differences between groups. The manual maximum KT-1000 arthrometer side-to-side difference was 2.1 +/- 1.6 mm for the revision group and 2.2 +/- 1.1 mm for the primary reconstruction group. The Lysholm score was significantly better in the primary reconstruction group (P = .014). The incidence of postoperative positive pivot-shift test results was not significantly different. The primary reconstruction group showed significantly less extension deficits. Functional testing revealed significantly better results for the primary reconstruction group for stair climbing, squatting, knee bending, and duck walk.

CONCLUSIONS: In our patient series, primary ACL reconstruction showed significantly better results in Lysholm score, although the IKDC score and objective knee stability showed no significant difference between the groups. Thus, parameters other than measurable knee stability must be responsible for the inferior results of the revision reconstruction group.