Morphological characteristics of femoral condyle in patients with high-grade femoral trochlear dysplasia based on MRI images

Abstract

Objective To quantitatively measure the morphological parameters of femoral condyle based on MRI images so as to determine the effect of anterior-posterior femoral condyle geometry on patellar instability (PI) in patients with high-grade femoral trochlear dysplasia. Methods A total of 82 series of knee joint MRI images from 74 patients with high-grade femoral trochlear dysplasia who underwent MRI scanning in our hospital from January 2014 to January 2021 were retrospectively selected. According to the results of clinical diagnosis and radiological imaging, they were further divided into patellar dislocation group (n=45) and non-patellar dislocation group (n=37). Subsequently, the morphological parameters related to the femoral condyle of knee joint were measured quantitatively in the MRI images, including posterior condylar angle (PCA), width of medial-lateral epicondyle (MLW), medial posterior condyle width (MPCW), lateral posterior condyle width (LPCW), medial anterior condyle length (MACL), lateral anterior condyle length (LACL), medial posterior condyle length (MPCL), and lateral posterior condyle length (LPCL). Intraclass correlation coefficient (ICC) was used to assess the intra- and inter-observer reliability of the quantitative MRI measurements. Results The MPCW and LACL values were significantly lower in the patellar dislocation group than the non-patellar dislocation group (P < 0.05), whereas there were no statistical differences in PCA, MLW, LPCW, MACL, MPCL and LPCL values between the 2 groups. The measurement results of all parameters had good consistency within and among the observers (ICC≥0.80). Conclusion The patients of patellar dislocation have shorter lateral anterior femoral condyle and narrower medial posterior femoral condyle, which may be risk factors for dislocation in those with high-grade trochlear dysplasia.

Keywords

• patellar instability
• trochlear dysplasia
• femoral condyle
• morphology