Comparison of initial fixation properties of sutured and nonsutured soft tissue anterior cruciate ligament grafts with femoral cross-pin fixation.

摘要

PURPOSE: To determine whether or not suturing a soft tissue graft in a whipstitch fashion is an essential procedure in order to ensure sufficient initial fixation strength of the cross-pin fixation technique in anterior cruciate ligament reconstruction. METHODS: Porcine digital extensor tendons were used as 4-stranded soft tissue grafts. Specimens were fixated within 52 porcine femoral bone tunnels using a cross-pin fixation technique (RigidFix; Ethicon, Norderstedt, Germany). In group I (n = 28), the looped-over part of the grafts was sutured using a whipstitch technique; in group II (n = 28) the grafts were not sutured. Initial fixation properties were determined using either a single cycle load to failure protocol or a dynamic loading protocol, submitting the graft to 1,000 cycles of flexion-extension loading between 0 degrees and 90 degrees , followed by ultimate loading to failure. The graft-pin interaction and the graft-tunnel interface was histomorphologically visualized in unloaded and dynamically loaded grafts. RESULTS: After dynamic loading, the residual displacement in sutured grafts was lower when compared to nonsutured grafts. The ultimate failure loads were significantly lower in nonsutured grafts when compared to sutured grafts after dynamic loading. The histomorphologic analysis demonstrated intratunnel displacement of nonsutured grafts after dynamic loading, while sutured grafts remained in situ. In cases where the cross-pins had not threaded the tendon loops, sutured grafts provided higher fixation strength and less graft displacement. CONCLUSIONS: The results of the present study suggest that suturing the looped-over portion of a quadruple tendon graft provides superior biomechanical graft fixation properties when compared to nonsutured grafts when using the femoral cross-pin fixation technique. CLINICAL RELEVANCE: Suturing the hamstring tendon graft in a whipstitch fashion is recommended for the femoral cross-pin fixation of an anterior cruciate ligament graft.