Summary

This study compares patient reported outcome measures and revision rates for different autograft options in patients with primary anterior cruciate ligament reconstruction without concomitant knee injury.

Abstract

Background

The quadriceps tendon is emerging as a popular autograft option for primary anterior cruciate ligament reconstruction. Limited studies have investigated the functional outcomes and survivorship of quadriceps tendon with variable results. Furthermore, most previous studies are confounded with the inclusion of patients with concomitant knee injuries alongside anterior cruciate ligament reconstruction. This study aims to investigate the differences in patient reported outcome measure scores and revision rates for quadriceps tendon in comparison with hamstring tendon and bone-patella-tendon-bone autografts. We use a cohort of patients who have had primary anterior cruciate ligament reconstruction without concomitant knee injuries.

Methods

Prospectively collected data linked to the New Zealand Anterior Cruciate Ligament Registry was used for the study. All patients who underwent a primary arthroscopic anterior cruciate ligament reconstruction with a valid 2 year patient reported outcome measure score were considered for the study. Patients who had associated knee injuries, previous knee surgery, or open procedures were excluded. The primary outcome was Knee Injury and Osteoarthritis Outcome Score (KOOS) and MARX scores at 2 years post-surgery. Secondary outcomes were all-cause revision and time to revision with a follow-up period of 8 years (time since inception of the Registry).

Results

2581 patients were included in the study; 1917 hamstring tendon, 557 bone-patella-tendon-bone, and 107 quadriceps tendon. All groups had comparable baseline characteristics. At 2 years, no significant difference in MARX score was found between the three groups (2y mean score; 7.36 hamstring, 7.85 bone-patella-tendon-bone, 8.05 quadriceps, P = 0.195). Further, no significant difference in KOOS scores were found between the three groups, with the exception of hamstring performing better than bone-patella-tendon-bone in the KOOS sports and recreation sub-score (2y mean score; 79.2 hamstring, 73.9 bone-patella-tendon-bone, P < 0.001). Similar revision rates were reported between all autograft groups (mean revision rate per 100 component years; 1.05 hamstring, 0.80 bone-patella-tendon-bone, 1.68 quadriceps, P = 0.083). Autograft revision was independent of age and gender variables.

Conclusions

All autograft groups had similar patient reported outcome measures and revision rates at 2 years when concomitant knee injuries were excluded. These results suggest that quadriceps tendon is a comparable autograft choice to the status quo in the early to intermediate follow-up period. Previous research that have suggested difference in outcomes between autograft options may have been confounded by concomitant knee injuries. Further research is required to quantify the longer term outcomes for quadriceps tendon use.