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 (LIPUS1-2 group) or in weeks 4 and 5 after intra-articular fracture (LIPUS4-5 group). In controls, the operated knees were not treated with LIPUS (LIPUS0 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 LIPUS1-2 and LIPUS4-5 groups, but not the LIPUS0 group, had either reached baseline or significantly recovered (70%, p <0.05) by week 8. PTOA pathology in both the LIPUS1-2 and LIPUS4-5 groups was less severe than that in the LIPUS0 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.