Fatty Infiltrate of the Lumbar Multifidus Muscles Predicts Return to Play in Young Athletes With Extension-Based Low Back Pain.
To evaluate the predictive value of fatty infiltrate of the lumbar multifidus muscles (LMM) for return to play in young athletes with extension-based low back pain (EB LBP).DESIGN
Retrospective cohort study.SETTING
Hospital-based sports medicine practice.PATIENTS
Sixty-two athletes, 61.3% female, and 38.7% male, mean age 14.8 years, with a primary complaint of EB LBP who underwent magnetic resonance imaging (MRI); 46.8% had a pars interarticularis stress reaction or fracture and 53.2% were MRI negative.INTERVENTIONS
A musculoskeletal fellowship-trained radiologist reviewed MRI for all subjects and graded the degree of fatty infiltrate of the LMM, using the Goutallier classification system (GCS), at the L4/L5 and L5/S1 levels.MAIN OUTCOME MEASURE
Days to return to play after first MD visit were correlated with the amount of fatty infiltrate in the LMM measured on MRI for each subject.RESULTS
When the level of fatty infiltrate increased to a 2 or 3 on the GCS (greater than fatty streaks in the muscle), the predicted probability of return to sport decreased significantly.CONCLUSION
Our study demonstrated that athletes with EB LBP and fatty infiltrate in the LMM had lower odds of return to sport compared with athletes with normal muscle.LEVEL OF EVIDENCE
II B.CLINICAL RELEVANCE
This study provides sports medicine clinicians with a prognostic tool to help manage young athletes with EB LBP. Clinicians can make decisions regarding rehabilitation and return to play based on MRI findings.