Efficacy of Intraligamentous Steroid Injection in Pain Reduction and Knee Motion Improvement in Patients with Mucoid Degeneration of the Anterior Cruciate Ligament.

BACKGROUND: This study assessed the efficacy and safety of fluoroscopy-guided intraligamentous steroid injections in managing mucoid degeneration of the anterior cruciate ligament (MDACL) in patients resistant to oral medication and intra-articular steroid injections. METHODS: A retrospective review of 294 knees diagnosed with MDACL via magnetic resonance imaging between October 2014 and June 2023 was conducted. After applying exclusion criteria and excluding patients who were asymptomatic or showed improvement with conservative treatment, 82 knees were included in the final analysis. Intraligamentous steroid injections were performed under C-arm fluoroscopy by a single orthopedic surgeon. Clinical data collected included the duration of the pain-free period, patient-reported outcome measures (PROMs; pain numeric rating scale, the International Knee Documentation Committee subjective score, Lysholm score, and Knee Injury and Osteoarthritis Outcome Score), range of motion, and other radiological measures. Symptom recurrence rates were determined using the Kaplan-Meier survival analysis. RESULTS: The average age at the time of injection was 64.0 years (range, 39-83 years), and the mean follow-up period was 19.5 months (range, 12-90 months). Pain improvement was noted in 78 of 82 knees (95.1%), with an average effect duration of 7.8 months (standard deviation, 9.1). Improvement of limitation of knee motion was observed in 49 of 50 cases (98.0%). Kaplan-Meier analysis indicated symptom recurrence rates of 19.5% at 3 months, 39.0% at 6 months, and 48.8% at 1 year. All PROMs significantly improved after injection for 6 months (p < 0.01) and then slightly declined. No patients reported post-procedure instability. CONCLUSIONS: Fluoroscopy-guided intraligamentous steroid injection demonstrated short-term efficacy in relieving pain and improving knee motion in MDACL patients resistant to conventional treatments, although further studies are warranted to confirm these findings.