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Assessing Lateral Patellofemoral Dislocations on MRI: A Novel Contusion Grading Approach for Predicting Recurrence
Nikhil Patel1, Griffin Harris1, Emily Johnson1
1University of Miami Miller School of Medicine, Miami, Florida, USA.
Abstract:
This retrospective cohort study evaluated the relationship between the location of lateral patellofemoral bony contusions on magnetic resonance imaging (MRI) and rates of recurrent patellar dislocation and surgical intervention using a novel MRI-based grading system. A total of 235 patients with MRI-confirmed lateral patellar dislocations were identified at a single academic institution, including 46 patients who underwent medial patellofemoral ligament (MPFL) reconstruction. Outcomes of patients managed nonoperatively were compared with those requiring surgical intervention. Bony contusions were identified in 66.8% of patients and were most commonly located within the anterior third of the lateral femoral condyle. Although contusion location was not significantly associated with the need for surgical intervention (p = 0.364), the presence of a bony contusion significantly predicted reinjury (p = 0.003), with 86% of reinjured patients demonstrating contusions on imaging. These findings suggest that while the location of the contusion may not influence the likelihood of surgery, the presence of a bony contusion is associated with an increased risk of recurrent instability. This novel MRI grading system offers a framework for future studies to stratify lateral patellar dislocations.
Insights
The location of lateral patellofemoral bony contusions on MRI does not predict surgery needs. However, the presence of these contusions significantly increases the risk of recurrent patellar dislocation.
Area of Science:
- Orthopedic surgery
- Radiology
- Sports medicine
Background:
- Lateral patellar dislocations often involve bony contusions.
- Understanding the prognostic value of these contusions is crucial for patient management.
Purpose of the Study:
- To evaluate the relationship between the location of lateral patellofemoral bony contusions on MRI and recurrent patellar dislocation.
- To assess the association between contusion characteristics and the need for surgical intervention.
Main Methods:
- Retrospective cohort study of 235 patients with MRI-confirmed lateral patellar dislocations.
- Utilized a novel MRI-based grading system for bony contusions.
- Compared outcomes of nonoperatively managed patients with those requiring surgery.
Main Results:
- Bony contusions were present in 66.8% of patients, predominantly on the lateral femoral condyle.
- Contusion location did not significantly correlate with the need for surgical intervention (p=0.364).
- The presence of a bony contusion significantly predicted reinjury (p=0.003), with 86% of reinjured patients showing contusions.
Conclusions:
- The presence of lateral patellofemoral bony contusions on MRI is a significant predictor of recurrent patellar instability.
- Contusion location does not appear to influence the likelihood of surgical intervention.
- A novel MRI grading system may aid in stratifying patients with lateral patellar dislocations.
