Use of Preoperative Magnetic Resonance Imaging to Predict Clinical Outcomes After Core Muscle Injury Repair.

BACKGROUND

Core muscle injury (CMI), often referred to as a sports hernia or athletic pubalgia, is a common cause of groin pain in athletes. Imaging modalities used to assist in the diagnosis of CMI include ultrasound (US) and magnetic resonance imaging (MRI).

PURPOSE

To determine if preoperative MRI findings predict clinical outcomes after surgery for CMI.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective cohort study was performed on a consecutive series of patients who were operatively treated for CMI by a single surgeon. CMI was diagnosed based on history, physical examination, and a positive US. In addition, all patients underwent a preoperative MRI. Patients were divided into 2 groups based on whether the MRI was interpreted as positive or negative for CMI. All patients underwent mini-open CMI repair. Patient-reported outcomes (PROs) were collected both pre- and postoperatively and included a visual analog scale (VAS) for pain, the University of California, Los Angeles (UCLA) activity score, and the modified Harris Hip Score.

RESULTS

A total of 39 hips were included in this study, of which 17 had a positive MRI interpretation for CMI (44%) and 22 had a negative MRI interpretation (56%). Mean age at the time of surgery was 35 years (range, 17-56 years), and mean follow-up was 21 months (range, 12-35 months). No significant difference was found between groups in mean age or time to follow-up. Patients in both groups demonstrated significant improvement from preoperative to most recent follow-up in terms of the UCLA activity score ( < .05). VAS scores significantly improved for patients with a positive MRI interpretation ( = .001) but not for those with a negative MRI interpretation ( = .094). No significant difference on any PROs was found between groups at the most recent follow-up.

CONCLUSION

Successful clinical outcomes can be expected in patients undergoing surgery for CMI diagnosed based on history, physical examination, and US. Patients with a preoperative MRI consistent with CMI may experience greater improvement in pain postoperatively, although MRI does not predict postoperative activity level in these patients.