The effect of shock wave treatment at the tendon–bone interface—an histomorphological and biomechanical study in rabbits

Abstract

Purpose. This study was performed to investigate the effect of shock wave treatment on the healing at tendon–bone interface in rabbits. Materials and methods. Thirty-six New Zealand White rabbits were used in this study. The anterior cruciate ligament was excised and replaced with the long digital extensor. The right knees (study group) were treated with 500 impulses of shock waves at 14 kV, while the left knees (control group) received no shock waves. Histomorphological studies were performed in 24 rabbits at 1, 2, 4, 8, 12 and 24 weeks. Biomechanical studies were performed in 12 rabbits at 12 and 24 weeks. Results. There was significantly more trabecular bone around the tendons noted in the study group compared with the control group at different time intervals after 4 weeks ( P < 0.05). The contacting between bone and tendon was significantly better in the study group than the control group after 8 weeks ( P < 0.05). The tensile strength of the tendon–bone interface was significantly higher in the study group than the control group at 24 weeks ( P = 0.018), whereas similar modes of graft failure were noted between the two groups. Conclusion. Shock wave treatment significantly improves the healing rate of the tendon–bone interface in a bone tunnel in rabbits. The effect of shock waves appears to be time-dependent.