Patellar tilt and patellar tendon-trochlear groove angle present the optimum MRI diagnostic reliability for patients with patellar instability.
PURPOSE: Describe in controls and in a population with patellar instability, MRI values of measurements representing major associated factors for patellar instability (patellar height, trochlear dysplasia and extensor mechanism alignment), as well as their cutoff values.
METHODS: 323 knee MRIs, 142 with patellar instability and 181 controls without patellofemoral complaints (anterior cruciate, medial collateral ligament, meniscus ruptures or normal) were evaluated. Means, normality values in the control population, ideal cutoff values through ROC curves analysis and interobserver reliability (ICC) were described for a series of measurements.
RESULTS: All measurements were statistically different in control and instability patients, except for the patellotrochlear index and TT-PCL. The interobserver ICC was good or excellent (above 0.75) only for the patellotrochlear index, patellar tendon - trochlear groove (PTTG) angle and patellar tilt. The optimal cutoff value for each measurement was: PTTG angle ≥25.3
CONCLUSION: Caton-Deschamps index (≥1.23), trochlear sulcus angle (≥153
Online ahead of print.
Gobbi RG, Cavalheiro CM, Giglio PN, Hinckel BB, Camanho GL. Patellar tilt and patellar tendon-trochlear groove angle present the optimum MRI diagnostic reliability for patients with patellar instability. Arthroscopy. 2023 Apr 26:S0749-8063(23)00309-2. doi: 10.1016/j.arthro.2023.04.005. Epub ahead of print. PMID: 37116551.