Analgesic effect of etidronate on degenerative joint disease.

In the present study, 80 patients with degenerative joint disease, spondylosis deformans, and/or osteoarthritis of the knee with back or joint pain, especially on movement and strain, were randomly divided into four groups. Group A received no etidronate, while groups B, C and D received 66, 133 and 200 mg/day etidronate, respectively, for 12 months. Every 3 months, after evaluating subjective pain on a visual rating scale (VRS), skin impedance was measured with subjects in a quiet sitting position and with the application of various strains on the spine and knee, including standing up from quiet sitting on a chair, bending forward to flex the spine, squatting to flex the knee, walking 20 paces on a flat floor, ascending 10 stair steps and descending 10 stair steps. A dose related improvement of subjective pain on the VRS with a parallel decrease in the percentage fall in skin impedance was noted. The intra-individual coefficients of variation (CV) of L1-L4 bone mineral density (BMD) on dual-energy X-ray absorptiometry were calculated as a possible index for spondylotic changes before and after treatment as an indication of spondylotic deformity, because no established method is yet available to evaluate such changes objectively. A dose-related decrease in CV of BMD was also noted, parallel to the analgesic effect.