Effect of short-wave diathermy on mobility and radiological stage of the knee in the development of experimental osteoarthritis.

The objective of the study was to determine the effect of short-wave diathermy on joint mobility and radiographic changes during the development of osteoarthritis. An experimental model for osteoarthritis was developed by periodic immobilization of rabbit knees. Nine rabbits was given short wave diathermy in the same knee 55 times for 5 minutes with a power of 50 W for 11 weeks. An identically immobilized group of 17 rabbits was used as control. The most significant effect on the mobility of the treated knee was the development of extension deficiency. This limitation developed within a week and was permanent. A smaller effect was found on flexion mobility. Flexion deficiency decreased at the end of the immobilization period and increased during remobilization, though at the end of the experiment there were no differences compared with the control. Radiographic changes were similar during the development of osteoarthritis in treated and non-treated groups.