Efficacy and safety of native type II collagen in modulating knee osteoarthritis symptoms: a randomised, double-blind, placebo-controlled trial

Corticosteroid injections for the treatment of osteoarthritis present a wide spectrum of effects ranging from detrimental to disease-modifying: A systematic review of preclinical evidence by the ESSKA Orthobiologic Initiative

PURPOSE

Aim of this systematic review of preclinical evidence was to determine the effects of intra-articular corticosteroid (CS) injections in joints affected by osteoarthritis (OA).

METHODS

A systematic review was performed on animal studies evaluating intra-articular CS injections for OA joints. The search was performed on PubMed, Cochrane, and Web of Science databases. A synthesis of the results was performed investigating CS effects by evaluating studies comparing CS with control groups. Morphological, histological, immunohistochemistry evaluations, clinical outcomes, biomarkers and imaging results were evaluated. The risk of bias was assessed according to the Systematic Review Centre for Laboratory Animal Experimentation's tool.

RESULTS

Thirty-two articles analysing CS effects in OA animal models were included (1079 joints), 18 studies on small and 14 on large animals. CS injections showed overall positive effects in at least one of the outcomes in 68% of the studies, while 16% reported a deleterious effect. CS improved cartilage and synovial outcomes in 68% and 60% of the studies, but detrimental effects were documented in 11% and 20% of the studies, respectively. Clinical parameters evaluated in terms of pain, lameness or joint swelling improved in 63% of the studies but deteriorated in 13%. Evidence is limited on imaging and biomarkers results, as well as on the best CS type, dose, formulation and injection protocol. The risk of bias assessment revealed a 28% low and an 18% high risk of bias.

CONCLUSION

Intra-articular CS injections induced a wide range of results on OA joints in experimental animal models, from disease-modifying and positive effects on pain and joint function at short-term evaluation to the lack of benefit or even negative effects. This underlines the need to identify more specific indications and treatment modalities to avoid possible detrimental effects while maximising the anti-inflammatory properties and the benefits of intra-articular CS in OA joints.

LEVEL OF EVIDENCE

Level II.

Efficacy and safety of collagen derivatives for osteoarthritis: A trial sequential meta-analysis

OBJECTIVE

To investigate the efficacy and safety of collagen derivatives for osteoarthritis.

DESIGN

PubMed, Embase, and Cochrane Library were searched till June 2023 for randomized controlled trials (RCTs) investigating collagen derivatives for treating osteoarthritis. Data were independently extracted by two authors. The risk of bias was assessed using the RoB 2 tool. A random-effects meta-analysis was performed within a frequentist framework. The certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations approach.

RESULTS

A total of 35 RCTs involving 3165 patients were included. The main analysis of the primary outcome was based on 25 RCTs involving 2856 patients. Collagen derivatives exerted small-to-moderate effects on pain alleviation (standardized mean difference [SMD] -0.35, 95% confidence interval [CI] -0.48 to -0.22, moderate certainty) and function improvement (SMD -0.31, 95%CI -0.41 to -0.22, high certainty) compared with the control. Collagen derivatives were safe; they did not increase the risk of withdrawal or adverse events compared with the control. The trial sequential analyses indicated that this study had sufficient statistical power for deriving definitive conclusions, confirming the robustness of our findings.

CONCLUSIONS

Strong evidence supports the efficacy and safety of collagen derivatives for osteoarthritis treatment.

Undenatured type II collagen and its role in improving osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease, affecting 32.5 million US adults or 242 million people worldwide. There is no cure for OA. Many animal and clinical trials showed that oral administration of undenatured type II collagen could significantly reduce the incidence of OA or alleviate the symptoms of articular cartilage. Type II collagen is an important component of cartilage matrix. This article reviewed research progress of undenatured type II collagen including its methods of extraction and preparation, structure and characterization, solubility, thermal stability, gastrointestinal digestive stability, its role in improving OA, and the mechanism of its action in improving OA. Type II collagen has been extensively explored for its potential in improving arthritis. Methods of extraction of type II collagen are inefficient and tedious. The method of limited enzymatic hydrolysis is mainly used to prepare soluble undenatured type II collagen (SC II). The solubility, thermal and gastrointestinal digestive stability of SC II are affected by the sources of raw material, pH, salt ions, and temperature. Oral administration of undenatured type II collagen improves OA, whereas its activity is affected by the sources, degree of denaturalization, intervention methods and doses. However, the influence of the structure of undenatured type II collagen on its activity and the mechanism are unclear. The findings in this review support that undenatured type II collagen can be used in the intervention or auxiliary intervention of patients with OA.