Efficacy of Acupuncture-Related Therapy in the Treatment of Knee Osteoarthritis: A Network Meta-Analysis of Randomized Controlled Trials

Knee osteoarthritis is one of the health conditions that most affects the quality of life of middle-aged and older adults worldwide. As the 11th leading cause of disability globally, it affects approximately 3.8% of the world's population and can reach 85% of people over 65 years of age in China. This degenerative joint disease causes pain, stiffness, and movement limitation, significantly impacting patients' daily activities. Although nonsteroidal anti-inflammatory drugs are frequently prescribed to relieve symptoms, they can cause important side effects, including gastrointestinal problems and damage to the liver and kidneys, particularly with prolonged use.

Given these limitations of conventional treatment, acupuncture and other techniques of traditional Chinese medicine (中醫) have proven to be promising alternatives for the management of knee osteoarthritis. These millennia-old practices are recognized in both Chinese guidelines and American Academy of Orthopaedic Surgeons guidelines as valid therapeutic options. However, several acupuncture modalities are available, such as electroacupuncture, warm needling, fire needling, and moxibustion (灸), and until recently there had been no systematic comparison of efficacy across these different methods.

This study aimed to fill that knowledge gap through a comprehensive network analysis, comparing the efficacy of different acupuncture techniques in the treatment of knee osteoarthritis. The investigators carried out a systematic search of English and Chinese scientific databases from inception through September 2020, seeking randomized controlled trials evaluating the use of acupuncture and moxibustion for this condition. The methodology included rigorous inclusion criteria, considering only studies with patients diagnosed with knee osteoarthritis according to well-established criteria and that assessed standardized outcomes such as pain, stiffness, and joint function through validated scales.

The results of this research were obtained through analysis of 40 randomized controlled trials involving 3,215 patients with knee osteoarthritis. The analysis demonstrated significant differences in efficacy across the various acupuncture modalities tested. Fire needling emerged as the most effective treatment, surpassing Western medicine, electroacupuncture, conventional acupuncture, warm needling, and sham acupuncture in pain score improvement. Warm needling proved superior to conventional acupuncture and Western medicine, while electroacupuncture was more effective than conventional acupuncture.

With respect to joint stiffness, both fire needling and warm needling were more effective than Western medicine and sham moxibustion. For joint function, fire needling, warm needling, and electroacupuncture demonstrated greater efficacy compared with conventional acupuncture and Western medicine.

These findings have important implications for both patients and health professionals. For patients, the results suggest that certain acupuncture modalities may offer superior symptom relief in knee osteoarthritis compared with conventional pharmacologic treatments, potentially with fewer side effects. Fire needling, in particular, showed the best results across virtually all assessed aspects, followed by warm needling and electroacupuncture. For health professionals, these data provide scientific evidence to guide the choice of the most appropriate acupuncture modality for each case, considering the individual characteristics of the patient and the severity of symptoms.

The study also found that the reported adverse events were only mild reactions, with no serious side effects, reinforcing the safety profile of these interventions.

It is important to acknowledge the limitations of this study for an appropriate interpretation of the results. The methodologic quality of the included clinical trials was considered moderate, with many studies not adequately describing methods of allocation concealment and blinding, which may have introduced bias into the results. In addition, there were inconsistencies in sample sizes, types of Western drugs used as controls, dosages, and treatment durations across studies, creating heterogeneity that may affect the reliability of conclusions. The analysis also detected possible publication bias and small-study effects, suggesting that some results may be overestimated.

Despite these limitations, this study represents a significant advance in understanding the relative efficacy of different acupuncture modalities for knee osteoarthritis. The evidence suggests a clear efficacy hierarchy, with fire needling showing the best results, followed by warm needling and electroacupuncture, all superior to conventional acupuncture and Western medicine. These findings may guide more informed clinical decisions, allowing health professionals and patients to choose the most appropriate treatment modality based on robust scientific evidence. Nonetheless, it is essential that future research include clinical trials of higher methodologic quality, with larger samples and multicenter designs, to confirm and refine these findings, ensuring that patients receive the best possible care for this disabling condition.