MRI Evaluation of Bipolar Bone Loss Using the On-Track Off-Track Method: A Feasibility Study

Area of Science:

• Orthopedic Surgery
• Radiology
• Medical Imaging

Background:

• Anterior shoulder instability often involves Hill-Sachs lesions and glenoid bone loss.
• Accurate preoperative assessment of these bone defects is crucial for effective surgical management.

Purpose of the Study:

• To evaluate the efficacy of the on-track off-track method using MRI for predicting engaging (off-track) lesions in patients with anterior shoulder instability.
• To correlate MRI findings with intraoperative arthroscopic assessments of engagement.

Main Methods:

• Retrospective review of 76 shoulder MRIs from 75 patients with a history of anterior shoulder instability.
• Two independent readers applied the on-track off-track method to predict lesion engagement.
• Comparison of MRI predictions with arthroscopic findings of engagement.

Main Results:

• The on-track off-track method demonstrated a sensitivity of 72.2% and specificity of 87.9% in predicting engaging lesions.
• Overall accuracy was 84.2%, with a positive predictive value of 65.0% and negative predictive value of 91.1%.

Conclusions:

• The on-track off-track MRI method reliably assesses bipolar bone loss in anterior shoulder instability.
• This imaging technique accurately predicts engaging lesions, informing preoperative surgical strategy for stabilization procedures.