Effect of Low-Intensity Pulsed Ultrasound on Joint Injury and Post-Traumatic Osteoarthritis: an Animal Study.

This study investigated the therapeutic potential of low-intensity pulsed ultrasound (LIPUS) in post-traumatic osteoarthritis (PTOA). Intra-articular fracture of the medial tibial plateau was surgically created in 30 rats. LIPUS was applied to the operated joints either for the first 2 wk (LIPUS group) or in weeks 4 and 5 after intra-articular fracture (LIPUS group). In controls, the operated knees were not treated with LIPUS (LIPUS group). The rats were monitored with weekly gait analysis and euthanized at week 8. Among the altered gait parameters, the maximal and average paw print areas in the LIPUS and LIPUS groups, but not the LIPUS group, had either reached baseline or significantly recovered (70%, p <0.05) by week 8. PTOA pathology in both the LIPUS and LIPUS groups was less severe than that in the LIPUS group (Mankin score: 5.4 and 4.5 vs. 8.8, p <0.05). In conclusion, LIPUS treatment partially improved the gait of the affected limbs and reduced cartilage degeneration in PTOA.