MR imaging spectrum of adolescent pubic symphyseal injuries/athletic pubalgia

Abstract

Background: Magnetic resonance imaging (MRI) findings associated with athletic pubalgia are well documented in the adult literature.

Objective: To describe the spectrum of MRI findings in adolescents with pubic symphyseal injuries/athletic pubalgia.

Materials and methods: This is an institutional review board approved, retrospective study of all patients < 18 years who were referred for MRI, over the last 10 years. Two pediatric musculoskeletal radiologists evaluated the MRI in consensus for the following findings: Chronic Salter-Harris (SH)-I equivalent fracture or asymmetric parasymphyseal ossific fraying, non-retractile muscular tear or retraction, and edema of the aponeurosis and arcuate ligament. Radiographs were also reviewed for Risser stage.

Results: Fifteen patients were identified (100% male, median age 17 years, IQR 16-17.6). Most patients (14/15, 93%) had either asymmetric parasymphyseal ossific fraying (4/15, 27%) or chronic SH-1 equivalent fracture (10/15, 67%) of the pubic symphysis, and all patients (15/15, 100%) had aponeurotic and arcuate ligament edema. Few patients had rectus abdominis muscular retraction (2/15, 13%), non-retractile muscular tear of the rectus abdominis (2/15, 13%), and/or adductor muscle (4/15, 27%). Risser stage was as follows: stages 0 (13%), 3 (7%), 4 (47%), and 5 (33%). The injuries in our limited data set were independent of skeletal maturity with no statistically significant association between any of the MRI findings and Risser stage.

Conclusion: The MR imaging spectrum of adolescent athletic pubalgia differs from the described findings in adults due to skeletal immaturity. The cleft sign described in adults manifests in adolescents as asymmetric parasymphyseal ossific fraying and chronic SH-1 equivalent fractures.

Keywords: Adolescent; Aponeurosis; Magnetic resonance imaging; Pubic symphysis; Rectus Abdominis; Sports.