Hip MRI findings and outcomes following imaging-guided hip injections

Objective: To determine if MRI findings prior to intra-articular corticosteroid hip infiltration are related to treatment outcomes. Methods: This prospective outcome study with retrospective MRI evaluation includes 100 consecutive patients with MRI within 6 months before a therapeutic intra-articular hip injection. Labrum, bone marrow, acetabular and femoral cartilage abnormalities were assessed by two radiologists blinded to patient outcomes: The proportion reporting "improvement"on the Patient's Global Impression of Change (PGIC) scale at 1 day, 1 week and 1 month follow-up were compared based on MRI findings using χ2. The t-test was used to compare pain change scores with MRI abnormalities. Results: Patients with a normal labrum in the posterosuperior quadrant were more likely to report PGIC "improvement"at 1 week compared to labral degeneration (p = 0.048). Significant differences in pain change scores were found at all time points for the labral anteroinferior quadrant (p = 0.001, 1 day; p = 0.010, 1 week; p = 0.034, 1 month) with the highest reduction in patients with labral degeneration. Females were 2.80 times more likely to report clinically relevant "improvement"at 1 day (p = .049) and 2.90 times more likely to report clinically relevant "improvement"at 1 month (p = .045). Conclusion: Cartilage defects and marrow abnormalities were not associated with outcomes. Patients with a normal labrum in the posterosuperior quadrant had better outcomes at 1 week. Patients with labral degeneration of the anteroinferior quadrant had higher levels of pain reduction at all time points. Females were significantly more likely to report PGIC "improvement".