Multiligament Injury, Medial Meniscus Tear, Hyperextension-Type Bone Bruise Pattern, and Younger Age Predict Magnetic Resonance Imaging-Defined Tear Location in Acute, Complete Posterior Cruciate Ligament Injuries.

PURPOSE: To characterize the epidemiology of posterior cruciate ligament (PCL) tear locations and identify clinicodemographic and injury-related predictors.

METHODS

This retrospective cohort study at a single institution included patients with acute, complete PCL injuries between 2008 and 2023. Exclusion criteria were PCL sprains without ligament disruption, partial tears, or chronic injuries (>60 days). Tears were classified by the relative length (%) of the intact distal remnant: type I (>90%), type Ib (femoral bony avulsion), type II (90%-75%), type III (75%-25%), type IV (10%-25%), type V (<10%), and type Vb (tibial bony avulsion). Clinicodemographic data, concomitant injury types, bone bruise patterns, and injury patterns were analyzed using univariate and multivariate logistic regression analyses.

RESULTS

A total of 148 magnetic resonance imaging studies met eligibility criteria (33% women; mean age, 36 ± 16 years). PCL tear-type distribution was type I 18.9%, type Ib 4.1%, type II 3.4%, type III 43.2%, type IV 15.5%, type V 3.4%, and type Vb 11.5%, with excellent interobserver reliability (κ = 0.96; 95% confidence interval [CI], 0.93-0.99; P < .001). Female patients were significantly older than men (41.6 ± 16.3 vs 32.7 ± 14.6 years; P = .001), more frequently sustained direct contusion injuries (44.4% vs 27.0%; P = .038), and less frequently cutting-sports-related injuries (2.3% vs 23.6%; P = .001). Independent predictors of proximal PCL tears (types I, Ib, and II) were multiligament injury (odds ratio [OR] = 8.2, 95% CI 2.9-26.5, P < .001), hyperextension-type bone bruise pattern (OR = 8.1, 95% CI 2.5-28.9, P < .001), medial meniscus tear (OR = 6.9, 95% CI 2.4-21.6, P < .001), and younger age (OR = 0.96 per year, 95% CI 0.9-1.0, P = .001). Midsubstance tears (type III) showed inverse associations, while no predictors were identified for distal tears (types IV, V, and Vb).

CONCLUSIONS

The proposed classification system reliably differentiated PCL tear locations. Multiligament injury, medial meniscus tear, hyperextension-type bone bruise pattern, and younger age were significant predictors of proximal tear location, whereas these factors were inversely associated with midsubstance tears.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.