Background: Current debate on treatment options for anterior cruciate ligament (ACL) reconstruction complicate the choice between hamstring and bone-patellar tendon-bone autografts. We hypothesized a priori that cumulative meta-analysis (a form of sensitivity analysis) might show that the evidence for reduction of morbidity by hamstring grafts could have been reached at an earlier time. Furthermore, we hypothesized a priori that modern state-of-the-art hamstring graft fixation technique would give similar results regarding stability as bone-patellar tendon-bone autografts.
Methods: We performed a cumulative meta-analysis and sensitivity analysis based on femoral graft fixation techniques to compare hamstring autograft and bone-patellar tendon-bone autografts in ACL reconstruction derived from a previously published meta-analysis.
Results: Cumulatively, that hamstring autograft reduces anterior knee pain had already reached statistical significance in 2001 (relative risk 0.49 (95%CI: 0.32-0.76; p = 0.001, I2 = 0%)). The modern endobutton hamstring graft fixation technique (2 studies) yielded similar stability in the Lachman test as bone-patellar tendon-bone grafts, with a relative risk of 1.1 (95%CI: 0.82-1.5; p = 0.6, I2 = 0%). Exclusion of the endobutton group explains the increased laxity in the hamstring graft group.
Interpretation: Cumulative meta-analysis strengthens the evidence for reduced morbidity using hamstring tendon autograft for anterior cruciate ligament reconstruction. Sensitivity analysis focusing on state-of-the-art hamstring graft fixation techniques further weakens the evidence that bone-patellar tendon-bone autografts provide better stability.