Trigger point acupuncture for treatment of knee osteoarthritis--a preliminary RCT for a pragmatic trial. 
There is evidence for the efficacy of acupuncture treatment in knee osteoarthritis, but it remains unclear which acupuncture modes are most effective.  We evaluated the effects of trigger point acupuncture on pain and quality of life in knee osteoarthritis patients, compared with acupuncture at standard points, and sham acupuncture.  Thirty patients (27 women, 3 men; aged 61-82 years) with non-radiating knee osteoarthritis pain for at least six months and normal neurological examination were randomised to one of three groups for the study period of 21 weeks.  Each group received five acupuncture treatment sessions.  The standard acupuncture point group (n=10) received treatment at traditional acupuncture points for knee pain; the trigger point acupuncture group (n=10) received treatment at trigger points; and the third group (n=10) received sham acupuncture treatment at the trigger points.  Outcome measures were pain intensity (visual analogue scale, VAS) and WOMAC index (Western Ontario and McMaster Universities Arthritis Index).  The groups were compared by the area under the curve method.  Five patients dropped out of the study because of lack of improvement, and one patient (in the trigger point acupuncture group) dropped out because of deterioration of symptoms; the remaining 24 patients were included in the analysis.  After treatment, the trigger point acupuncture group reported less pain intensity on VAS than the standard acupuncture or sham treatment group, but both the trigger point acupuncture and standard acupuncture groups reported improvement of function of knee.  There was a significant reduction in pain intensity between pre-treatment and five weeks after treatment for the trigger point acupuncture (P<0.01) and standard acupuncture groups (P<0.01) included in the analysis, but not for the sham treatment group.  Group comparison using the area under the curves demonstrated a significant difference only between trigger point acupuncture and sham treatment groups analysed (P<0.025 for VAS, and P<0.031 for WOMAC).  These results suggest that trigger point acupuncture therapy may be more effective for osteoarthritis of the knee in some elderly patients than standard acupuncture therapy.