Trochlear dysplasia is associated with distal patellar fracture

While trochlear dysplasia is recognized as a key factor in patellar instability, its association with specific patellar fracture patterns remains unclear. This study investigates the relationship between trochlear dysplasia and patellar fractures through morphological analysis.

In this prospective cohort study of 318 patients with acute patellar fractures (January to June 2021), preoperative CT scans were analyzed for trochlear dysplasia parameters: sulcus angle, trochlear depth, and lateral trochlear inclination. Fractures were classified using AO/Orthopaedic Trauma Association (OTA) criteria with emphasis on inferior pole involvement. Multivariable logistic regression was used to identify morphological predictors of fracture type.

Trochlear dysplasia was identified in 152 (47.80%) of patients, with a mean sulcus angle of 144.44° (SD 11.16°), trochlear depth of 4.43 mm (SD 1.33), and lateral trochlear inclination of 18.25° (SD 4.89°). Fractures classified as AO/OTA types A and C1.3 were more prevalent in patients with trochlear dysplasia. Logistic regression analysis showed that the sulcus angle significantly influenced the occurrence of the distal fractures (p < 0.001, odds ratio (OR) = 1.15, 95% CI 1.111 to 1.187).

Trochlear dysplasia, particularly manifested by an increased sulcus angle, is significantly associated with distal patellar fractures. These findings highlight the importance of preoperative morphological assessment in predicting fracture patterns and tailoring clinical management.