Summary

Unaddressed posterior tibial slope is associated with increased failure risk of revision ACL reconstruction

Abstract

Objective

Failure of revision ACL reconstruction is not as well studied as primary ACL reconstruction. This study aimed to compare reasons for failure of primary and revision ACL reconstructions and explore patient-specific factors that contribute to failure risk.

Methods

A retrospective chart review was performed of patients who underwent revision ACL reconstruction at an academic medical center from 2004 to 2021. Patients were placed in the failed primary (FP) or failed revision (FR) ACL reconstruction cohort, depending on the number of reconstructions failed (one or two). Causes of failure were determined using the patient’s history, physical evaluation, radiographs, and arthroscopic evaluation. Primary failure modes were categorized as technical error, trauma, biological failure, or a combination of these. Patient demographics were recorded. Posterior tibial slope was measured on radiographs. The percentage of patients in each cohort with a tibial slope (≥12°) was identified.

Results

Overall, 217 patients were included (median age, 27 years; 61% Male; mean BMI, 26.8 kg/m2). There were 160 patients (74%) in the FP group and 57 patients (26%) in the FR group. The FP group’s modes of failure were technical error (16%), trauma (35%), biological failure (<1%), and combination (49%), and the FR groups were technical error (7%), trauma (51%), biological failure (9%), and combination (33%). There was a significantly increased incidence of technical error (64% vs. 39%; p < 0.01) in the FP group. A tibial slope (≥12°) was more common in the FR group (35 patients, 61%) than the FP group (53 patients, 33%), p < 0.001).

Conclusions

Patients who failed revision ACL reconstruction demonstrated an elevated incidence of tibial slope ≥ 12 degrees, and a lower incidence of technical error compared to patients who failed primary ACL reconstruction