Introducing Increased Lateral Tibial Height and Decreased Medial Meniscal Bone Angle as Independent Risk Factors for...

Tibiofemoral rotational malalignment, recognized as a risk factor for recurrent patellar dislocation (RPD), has become a research focus. Although the relationship between femoral morphology and RPD is widely studied, the association between RPD and the tibial plateau and meniscus geometries related to the tibiofemoral rotation remains unexamined.

After accounting for the classic risk factors associated with knee rotation-tibial tuberosity-trochlear groove (TT-TG) distance and tibiofemoral angle (TFA)-targeted anatomical parameters are independently associated with adult RPD.

Cross-sectional study; Level of evidence, 3.

This retrospective case-control study included 50 adult patients with RPD and 50 age-, sex-, and body mass index-matched controls. Knee magnetic resonance imaging scans were used to assess parameters-including the lateral tibial slope (LTS), medial tibial slope (MTS), lateral tibial height (LTH), medial tibial depth (MTD), medial meniscal bone angle (MMBA), MTS-LTS (slope difference), MTS: LTS ratio, MTS: MMBA ratio, TT-TG distance, and TFA. Differences among groups were compared; a multivariate logistic regression model was created to evaluate independent factors, and the diagnostic performance of the substantial risk factors, individually and in combination, was assessed.

The LTS (P = .002), LTH (P < .001), MMBA (P < .001), MTS-LTS (P = .001), MTS: LTS ratio (P = .001), TT-TG distance (P < .001), and TFA (P < .001) were found to be significantly different between the groups. Logistic regression analysis identified the LTH (odds ratio [OR], 0.409; P = .014), MMBA (OR, 1.456; P < .001), and TT-TG distance (OR, 0.752; P ≤ .001) as independent adult RPD risk factors. Receiver operating characteristic analysis showed that combining LTH, MMBA, and TT-TG distance had excellent predictive ability for adult RPD, with an area under the curve (AUC) of 0.888, sensitivity of 82%, and specificity of 88%, surpassing their diagnostic values (AUCs, 0.694-0.804).

The decreased LTS, increased LTH, decreased MMBA, increased MTS-LTS, and increased MTS: LTS ratio were associated with adult RPD. Importantly, even after controlling for TT-TG distance and TFA, increased LTH and decreased MMBA persisted as independent risk factors for adult RPD.