Summary

The association of tibial and femoral tunnels malposition, as well as the meniscal and cartilage status at the time of surgery, is significantly associated with an advanced radiographic stage of osteoarthritis at a mean follow-up of 10 years.

Abstract

Introduction

Most studies evaluating tunnel positioning after anterior cruciate ligament reconstruction and the development of osteoarthritis use standard radiographs, which do not allow accurate assessment of tunnel positioning. The aim of this study was to compare the long term radiological development of osteoarthritis according to tunnel positioning identified on 3D reconstructions from a postoperative CT scan.

Material And Methods

In this retrospective single-center study, 300 patients underwent ACL reconstruction using the outside-in technique between February 2012 and December 2015. Among these patients, 76 had postoperative control CT scans and knee X-rays at the last follow-up. The mean age was 33.1 years [15-61]. The patellar tendon graft was used in 92.1% of cases. Only one patient had significant preoperative osteoarthritis. The mean follow-up was 9.6 years [8.5-12.7]. Tunnels positioning was studied on 3D reconstructions from a postoperative CT scan using the techniques of Magnussen et al. for the femur and Cremer et al. for the tibia. Femoral tunnels of type II and III (F) and tibial tunnels with an anteroposterior gap = 5 mm (AP) and/or mediolateral gap = 2 mm (ML) compared to the native ACL location were considered malpositioned. Radiographic osteoarthritis grades C and D according to the IKDC classification were considered as advanced. Factors associated with the progression to osteoarthritis were also studied, including age, sex, BMI, time between injury and surgery, type of sport, cartilage and meniscal lesions, and revisions.

Results

At the last follow-up, 18.4% of the patients had an advanced radiographic stage of osteoarthritis (IKDC C or D). The distribution of malpositioned tunnels was as follows: F (30.3%), AP (28.9%), ML (31.6%), AP+ML (11.8%), AP+ML+F (5.3%). There was a significant association between AP+ML and AP+ML+F tunnels and the IKDC C/D group (p = 0.022 and p < 0.001, respectively). The performance of a meniscectomy and the presence of cartilage lesions were significantly associated with an advanced radiographic stage of osteoarthritis (p < 0.001 and p = 0.008, respectively).

Conclusion

The association of tibial and femoral tunnels malposition, as well as the meniscal and cartilage status at the time of surgery, is significantly associated with an advanced radiographic stage of osteoarthritis at a mean follow-up of 10 years.