Clinical Outcomes and Magnetic Resonance Imaging Evaluation of Autologous Protein Solution Treatment for Knee Osteoarthritis

TL;DR

This study shows that a single injection of autologous protein solution improves knee osteoarthritis symptoms, but does not significantly change structural damage seen on MRI.

Contribution

The study provides new evidence on the clinical efficacy and MRI outcomes of autologous protein solution in knee osteoarthritis.

Findings

APS injection improved KOOS scores for symptoms, pain, and quality of life across all KL grades.

KL2 patients showed greater improvements in activity and quality of life compared to KL3 and KL4 patients.

MRI showed no significant improvement in cartilage damage, BMLs, synovitis, or meniscal status.

Abstract

Objective: This study aims to investigate the clinical outcomes and magnetic resonance imaging evaluation (MRI) of intra-articular injection of autologous protein solution (APS) in patients with knee osteoarthritis of varying severities.

Methods: A retrospective analysis was conducted on the clinical data of consecutive subjects with knee osteoarthritis (KOA) of varying Kellgren-Lawrence (KL) grades who underwent a single APS injection. The Knee injury and Osteoarthritis Outcome Score (KOOS), covering symptoms (S), pain (P), activity (A), sports (SP), and quality of life (Q), was used to evaluate the patients at pre-treatment and 12 months post-treatment. Minimal Clinically Important Difference (MCID) and Osteoarthritis Research Society International Set Responder Criteria Osteoarthritis Clinical Trials Revisited (OMERACT-OARSI) tools were used to observe improvement in different KL grades. Additionally, an MRI was performed pre-treatment and 12 months post-treatment. Semi-quantitative analysis (Magnetic Resonance Imaging Osteoarthritis Knee Score (MOAKS)) was applied to assess bone marrow lesions (BMLs), articular cartilage, osteophytes, synovitis and effusion, and meniscal lesions in various subregions of the knee joint.

Results: A total of 53 patients (66 knees) were included in the final analysis. At 12 months post-treatment, overall KOOS scores showed improvement. The responder rates were 78.6% (11 knees) in KL2, 68.4% (13 knees) in KL3, and 51.5% (17 knees) in KL4. Significant improvements were observed in KOOS-S, KOOS-P, and KOOS-Q across all patients. KOOS-A and KOOS-SP demonstrated statistically significant differences only in the KL2 and KL4 groups (P < 0.05). Comparisons of KOOS score differences between groups revealed that patients in the KL2 group experienced greater improvements in activity levels and quality of life compared to those in the KL3 and KL4 groups (P < 0.05). MOAKS evaluation revealed no significant improvement in cartilage damage, BMLs, synovitis-effusion, and meniscal status. In the KL4 group, the post-treatment scores for patellar superior and inferior osteophytes were higher than the pre-treatment scores (P = 0.039).

Conclusion: This study provides evidence supporting the clinical efficacy of a single intra-articular injection of APS in KOA. However, the therapeutic effect of APS for structural changes in imaging remains limited.

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