Bioabsorbable interference screw versus bioabsorbable cross pins: influence of femoral graft fixation on the clinical outcome after ACL reconstruction

PURPOSE: The aim of this study was to evaluate the clinical outcome and differences in anterior–posterior laxity of ACL reconstruction using a bioabsorbable interference screw for femoral graft fixation when compared to femoral bioabsorbable cross pin fixation. METHODS: Clinical outcome was evaluated among 59 patients 1 year after arthroscopic ACL reconstruction with hamstrings graft in a prospective, non-randomised study. In 31 cases, femoral fixation of the graft was performed using a bioabsorbable interference screw. In 28 cases, two bioabsorbable cross pins were used for femoral fixation. Patients were evaluated using Tegner, Lysholm and Marshall scores, the visual analogue scale for pain and KT-1000 arthrometer measurement. RESULTS: No significant difference (P ≥ 0.05) was observed at follow-up for the knee scores. The average Tegner score was 5.83 points (±2.00) for the interference screw fixation and 5.83 points (±1.24) for the cross pin fixation; the average Lysholm score was 93.58 (±5.79) to 92.72 (±6.34) points; and the average Marshall score 46.72 (±2.4) to 47.30 (±2.35) points. No significant difference was found for the visual analogue scale for pain. KT-1000 arthrometer measurement revealed a significant (P < 0.05) difference in the mean side-to-side anterior translation at all applied forces. At 67 N, the mean difference was 1.53 mm (±1.24) in the interference screw group and 0.47 mm (±1.18) in the cross pin group (P < 0.05). At 89 N, the mean differences were 1.85 mm (±1.29) versus 0.59 mm (±1.59), respectively, (P < 0.05), and maximum manual displacements were 2.02 mm (±1.26) versus 1.22 mm (1.18; P < 0.05). CONCLUSIONS: In ACL reconstruction with hamstrings graft, similar clinical results are obtained for the use of bioabsorbable cross pins when compared to bioabsorbable interference screws for femoral fixation. Cross pin fixation was superior with regard to the anteroposterior laxity as measured with KT-1000.