Dry needling on latent and active myofascial trigger points versus oral diclofenac in patients with knee osteoarthritis: a randomized controlled trial

This randomized controlled trial investigated the efficacy of dry needling at myofascial trigger points compared with oral diclofenac in patients with knee osteoarthritis, representing an innovative approach to managing this common degenerative condition. Knee osteoarthritis primarily affects older adults and causes significant pain, stiffness, and functional limitation that profoundly impact quality of life. Treatment has traditionally been based on nonsteroidal anti-inflammatory drugs such as diclofenac, but their gastrointestinal, renal, and cardiovascular adverse effects limit prolonged use. Investigators recruited 98 patients older than 55 years with radiographically confirmed knee osteoarthritis (Kellgren-Lawrence grades II-IV) and a minimum pain intensity of 4 on a 0-10 scale.

All participants had at least one active or latent myofascial trigger point in muscles associated with the knee. Participants were randomized into two groups: the dry needling group (49 patients) received weekly needling treatment at trigger points in the quadriceps, hamstrings, tensor fasciae latae, hip adductors and abductors, gastrocnemius, soleus, and popliteus, combined with home stretching exercises; the control group (49 patients) received oral diclofenac sodium 75 mg daily along with the same stretching exercises. Dry needling followed strict criteria for trigger point identification, including a palpable taut band, hypersensitive spot, and reproduction of the patient's symptoms. Treatment was performed until a local muscle twitch response was obtained, indicating release of the trigger point.

Outcome measures included the Numeric Pain Rating Scale (NPRS), the WOMAC Index for osteoarthritis assessment, and knee range of motion, evaluated before treatment, after 6 weeks, and at 6-month follow-up. Of the 98 initial participants, 77 completed the study (42 in the dry needling group and 35 in the diclofenac group). Results demonstrated significant superiority of dry needling on all measures evaluated. On the NPRS pain scale, the dry needling group showed a reduction from 6.1 to 2.5 points, while the diclofenac group decreased from 5.9 to 3.7 points after 6 weeks.

More impressively, at 6-month follow-up, the dry needling group maintained improvement with a score of 2.7, while the diclofenac group showed partial relapse to 3.7 points. On the total WOMAC index, dry needling produced improvement from 39.4 to 15.8 points, compared with improvement from 37.2 to 22.4 points in the diclofenac group. Knee range of motion also improved significantly more in the dry needling group. Trigger point prevalence analysis revealed important findings: latent trigger points were found in 50-71% of the muscles evaluated, being most prevalent in the gastrocnemius, while active trigger points ranged from 7-54% across different muscles.

This is the first study to include both active and latent trigger points in the treatment of knee osteoarthritis, recognizing that both contribute to muscle dysfunction and biomechanical alterations that can accelerate joint degeneration. Adverse effects were minimal: two patients in the dry needling group discontinued because of persistent post-treatment pain, while three patients in the diclofenac group withdrew because of gastrointestinal effects. The clinical implications are significant, suggesting that dry needling can offer an effective and lasting alternative to traditional anti-inflammatory drugs, addressing not only pain but also the underlying muscle imbalances that perpetuate joint dysfunction. The study has limitations such as lack of direct supervision of home exercises and absence of a placebo group, but it provides robust evidence for incorporating this technique into multimodal management of knee osteoarthritis.