Summary

Concomitant injury patterns between isolated, multiligament, and revision posterior cruciate ligament reconstruction show increased rates of medial femoral condyle, medial tibial plateau, and lateral femoral condyle cartilage injuries in the revision setting and demonstrates a unique approach in confirming the detrimental effects of PCL injury on the medial compartment.

Abstract

Introduction

Evaluation of patients undergoing revision posterior cruciate ligament reconstruction (PCL-R) can identify pathology associated with PCL deficiency and failed reconstruction. Study of revision PCL-R, which is scarce, may further elucidate the role of the PCL in knee stability by demonstrating the consequences of multiple instances of PCL deficiency on the menisci and cartilage. The purpose of this study was to investigate the demographic profile and concomitant injury patterns in patients undergoing primary isolated PCL-R, multiligament involving PCL-R, and revision PCL-R.

Methods

A retrospective review was performed on all patients undergoing PCL-R at a single academic institution between 2008 and 2020. Demographics, injury and surgical details, and concomitant ligament, meniscus, and cartilage data were extracted. Exclusion criteria included PCL repair and incomplete surgical data. Multiligament PCL-R was defined as concurrent surgery on at least one other knee ligament (i.e., anterior cruciate ligament [ACL], medial collateral ligament [MCL]/posteromedial corner [PMC], or lateral collateral ligament [LCL]/posterolateral corner [PLC]). The differences in demographics and injury profiles across groups were analyzed. Categorical variables were analyzed with chi-square or Fisher’s exact tests, and continuous variables were analyzed with t-test or Kruskal-Wallis test. Post-hoc comparisons were adjusted for multiplicity with the Bonferroni-Hochberg procedure.

Results

Of 225 patients undergoing PCL-R, primary isolated PCL-R was performed in 60 patients (27%), multiligament PCL-R in 152 patients (67%), and revision PCL-R in 13 patients (6%). Demographics and mechanism of injury were similar between groups. Concomitant ligament injuries in patients undergoing multiligament PCL-R most commonly involved the ACL (65%), followed by LCL/PLC (58%) and MCL/PMC (41%). The prevalence of associated medial and lateral meniscus lesions was not statistically significant between groups. Evaluation of associated cartilage injuries showed that two-thirds of all revision PCL-R cases demonstrated chondral injury. The prevalence of cartilage injury on the medial femoral condyle was significantly greater in the revision (64%) compared to the multiligament (26%) and isolated groups (24%, p = 0.03). Cartilage injury on the medial tibial plateau was significantly more prevalent in revision (36%) and multiligament (20%) PCL-R compared to isolated PCL-R (7%, p = 0.02). Revision and multiligament PCL-R had significantly more cartilage injury on the lateral femoral condyle compared to the isolated group (27% vs. 14% vs. 3%, p = 0.03).

Conclusion

Concomitant injury patterns between isolated, multiligament, and revision PCL-R show increased rates of cartilage injuries in the revision setting, specifically localized to the medial femoral condyle, medial tibial plateau, and lateral femoral condyle. This is a unique approach to demonstrating the detrimental effects of PCL injury on the medial compartment, likely due to altered kinematics. Surgeons should be aware of the high prevalence of medial compartment chondral pathology during preoperative planning and patient counseling for revision PCL-R.