Randomised controlled trial of extraarticular gold bead implantation for treatment of knee osteoarthritis: a pilot study.

The primary objective of this double-blind, randomised, controlled trial was to determine if implanting gold beads at five acupuncture points around the knee joint improves 1-year outcomes for patients with osteoarthritis (OA) of the knee. Participants were 43 adults aged 18-80 years with pain and stiffness from non-specific OA of the knee for over a year. The intervention was blinded implantation of gold beads at five acupuncture points around the affected knee through a hypodermic needle, or needle insertion alone. Primary outcome measures were knee pain, stiffness and function assessed by the patient at 0, 1, 3, 6, 9 and 12 months and knee score and knee function assessed by an orthopaedic surgeon at 0, 6 and 12 months. Within the first month, three patients dropped out. The remaining 21/19 patients in the intervention/control groups generally improved, but there was no statistically significant difference between the groups. The improvement was shown in the patients' self-assessment scores that decreased from randomisation until 1 year later (intervention/control group, medians): pain -1.92/-2.18 (P = 0.95, F test, general linear mixed model); stiffness -0.93/-0.43 (P = 0.11); function -7.23/-3.36 (P = 0.63). The surgeon's scores also generally improved, i.e. increased: knee score +16.4/+8.2 (P = 0.65); knee function +10.5/+5.8 (P = 0.79). In the protocol-based subgroup analysis, the 15 intervention patients of the 32 patients who had a positive response to the initial conventional acupuncture had greater relative improvements in self-assessed outcomes. The treatment was well tolerated. This 1-year pilot study indicates that extraarticular gold bead implantation is a promising treatment modality for patients with OA of the knee. The new treatment should be tested in a larger trial including only patients who respond positively to initial conventional acupuncture.