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_1-2 group) or in weeks 4 and 5 after intra-articular fracture (LIPUS_4-5 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 LIPUS_1-2 and LIPUS_4-5 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 LIPUS_1-2 and LIPUS_4-5 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.