Predictors of Pediatric Anterior Cruciate Ligament Injury: The Influence of Steep Lateral Posterior Tibial Slope and Its Relationship to the Lateral Meniscus.

PURPOSE: To examine the relationship between posterior tibial slope and lateral meniscal bone angle (LMBA) on anterior cruciate ligament (ACL) tear risk in a pediatric population. METHODS: In this case-control study, non-contact ACL-injured pediatric patients with no significant lateral meniscal lesions were matched by age and sex in a 1:1 ratio to a group of radiologically normal controls. Knee magnetic resonance imaging (MRI) studies were analyzed by 3 independent, blinded observers measuring the medial posterior tibial slope (MTS), lateral posterior tibial slope (LTS), and LMBA. Sagittal slope asymmetry was calculated as the absolute difference in degrees between slopes, and the relationship between LMBA and LTS was calculated as a ratio. Binary logistic regressions identified independent predictors of ACL injury. Receiver operator characteristics were performed to determine predictive accuracy. RESULTS: 20 study patients were compared with 20 sex- and age-matched controls (age 14.8 ± 2.42, mean ± standard deviation). LTS was significantly higher in the ACL-injured group (11.30° ± 3.52° versus 7.00° ± 2.63°, P = .0001), as were the absolute slope difference (7.10 ± 2.92° versus 3.14 ± 3.25°, P = .0002) and LTS:LMBA ratio (0.46 ± 0.17 versus 0.26 ± 0.12, P = .0001). No significant differences were observed for MTS or LMBA. Independent predictors were LTS (odds ratio [OR] 1.58, 95% confidence interval [CI] 1.18 to 2.13, P = .002), LTS:LMBA ratio (OR 3.13, 95% CI 1.48 to 6.62, P = .003), and absolute slope difference (OR 1.65, 95% CI 1.17 to 2.32, P = .005). LTS:LMBA ratio was the strongest predictor variable (area under the curve 0.86). CONCLUSION: This study suggests that LTS, absolute slope difference, and LTS:LMBA ratio are significant pediatric ACL-injury risk factors. All 3 demonstrate good predictive accuracy; however, the relationship between steep LTS and shallow LMBA was the strongest predictor. LEVEL OF EVIDENCE: III, case-control study.

Intramedullary tibial nailing using infrapatellar and suprapatellar approaches: A systematic review and meta-analysis.

INTRODUCTION: Intramedullary nailing of diaphyseal tibial fractures has become the gold standard method of fixation with high rates of union and low complication rates reported. The suprapatellar (SP) approach may have many advantages over the traditional infrapatellar (IP) approach. Controversy exists due to potential damage to the patellofemoral joint leading to persistent anterior knee pain. This systematic review and meta-analysis aims to evaluate the clinical and procedural outcomes of the SP approach in comparison to the traditional IP approach. METHOD: In this PRISMA compliant systematic review and meta-analysis, five databases including MEDLINE, EMBASE, Web of Science, Cochrane Library and CINAHL were searched from inception until May 2020. Randomised controlled trials (RCTs) and comparative observational studies involving adults with tibial fractures treated with intramedullary nail fixation using either the suprapatellar or infrapatellar approach were included. Data extracted included demographics, functional knee scores, fluoroscopy exposure, insertional accuracy and adverse events. The primary outcome was validated functional knee scores. Risk of bias was calculated using the Cochrane risk of bias tool version 2 (RoB 2) and Newcastle-Ottawa Scale (NOS). RESULTS: In total 16 studies were included consisting of 5 RCTs and 11 comparative observational studies. This included 1750 total operations with 810 in the SP group and 940 in the IP group. Meta-analysis was performed on the studies where appropriate data was reported. The SP approach demonstrated superior Lysholm scores (Mean Difference (MD) 5.63 [95% Confidence Interval (CI): 2.81 to 8.44]), reduced fluoroscopy times (MD -38.12 sec [95% CI: -47.96 to -28.28]) and increased entry point accuracy (Standard Mean Difference (SMD) -0.90 [95% CI: -1.22 to -0.59]). No differences in complication rates or blood loss were found. CONCLUSION: Based on the data presented in this review, intramedullary nailing of the tibia using the SP approach demonstrates superior Lysholm knee scores, greater entry point accuracy and reduced fluoroscopy exposure with equivalent risk of developing complications when compared to the IP approach.