Abstract
OBJECTIVE: This study was performed to explore the effect of intra-articular injection of autologous platelet-rich plasma (PRP) on refractory pain after low-grade medial collateral ligament (MCL) injury. METHODS: In total, 52 patients with refractory pain after low-grade knee MCL injury were treated by intra-articular injection of autologous PRP. Every patient received a 5-mL intra-articular injection of autologous PRP once weekly for 3 weeks. All patients were evaluated by the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form score before treatment and 1, 3, and 6 months after treatment. Magnetic resonance imaging of the knee was performed to observe the healing of the MCL injury 6 months after treatment. RESULTS: After one injection, the patients’ pain was greatly decreased and they stopped taking nonsteroidal anti-inflammatory drugs. The IKDC Subjective Knee Evaluation Form scores were significantly better after than before treatment; however, there were no significant differences among the various post-treatment time points. Magnetic resonance imaging showed that the low-grade MCL injury had completely healed, and no edema was present around the MCL. CONCLUSIONS: Intra-articular injection of autologous PRP is an effective treatment for refractory pain after low-grade MCL injury.