gms | German Medical Science

Objectives: Anterior cruciate ligament (ACL) injuries are often associated with concomitant meniscal- and/or cartilage lesions. The posterior tibial slope (PTS) and the lateral femoral condyle ratio (LFCR) have been identified as risk factors for ACL injury. The purpose of this study was to evaluate the impact of PTS and LFCR on the prevalence of concomitant meniscal and/or cartilage injuries in acute (<12 weeks) and delayed (>12 weeks) primary ACL reconstruction. It was hypothesized that increased PTS and increased LFCR are associated with an increased risk for concomitant injuries in patients with delayed compared to acute primary ACL reconstruction.

Methods: Consecutive patients who underwent primary ACL reconstruction between January 2011 and December 2021 were retrospectively reviewed. Medical records were screened and patient-, injury- and surgery-related data were collected. Patients were categorized by the time to surgery after ACL injury (acute ACL reconstruction: <12 weeks; delayed ACL reconstruction: >12 weeks). Medial PTS and LFCR were measured on preoperative strict lateral knee radiographs. An adjusted logistic regression analysis was performed to stratify the risk of concomitant injuries, in which the following variables were included: Age, sex, PTS and LFCR. Level of significance was set at p <0.05.

Results and conclusion: In total, 350 patients (63% males) with a mean age of 30.6 ± 10.6 years at the time of primary ACL reconstruction were included. For patients undergoing acute ACL reconstruction increased PTS was associated with lower odds for meniscal and cartilage injuries (odds ratio [OR] 0.86; 95% CI, 0.75, 0.98; p= .023). For patients undergoing delayed ACL reconstruction increased LFCR showed higher odds for meniscal and cartilage injuries ([OR] 1.20; 95% CI, 1.03, 1.43; p=0.029). In addition, higher age showed higher odds ([OR] 1.09; 95% CI, 1.03, 1.17; p=0.006) and female sex lower odds ([OR] 0.17; 95% CI, 0.05, 0.57; p=0.006) for concomitant injuries in patients undergoing delayed ACL reconstruction. The other factors included in the respective subgroup regression analysis did not have a statistically significant impact on the prevalence of concomitant injuries.

In patients with higher PTS, acute ACL reconstruction within 12 weeks of injury is associated with less concomitant injuries. In patients with a higher LFCR, higher age, and male sex delayed ACL reconstruction after 12 weeks of injury is associated with more concomitant injuries. Therefore, early ACL reconstruction is recommended in older male patients with high LFCR.