Biological Mechanism of Extracorporeal Shock Wave Combined with Platelet-Rich Plasma on the Healing of Reconstructed Tendon Bone in a Rabbit Model of Rotator Cuff Tear

Abstract

To investigate the biological mechanism of the effect of extracorporeal shock wave combined with plateletrich plasma on the healing of reconstructed tendon bone in a rabbit model of rotator cuff tear. 40 New Zealand white rabbits aged 4-5 mo were selected, 32 rabbits were randomly selected and each rabbit was executed at 4-8 w postoperatively and these rabbits were randomly divided into control group, shockwave group, platelet-rich plasma group and shockwave+platelet-rich plasma group. The tendon bone healing site was observed at 2, 4 and 8 w after surgery and the content of transforming growth factor beta 1 and basic fibroblast growth factor were measured by reverse transcription-polymerase chain reaction and western blot, while the biomechanical test was performed on the tendon bone healing specimens. The results showed that the content of neovascularization at the tendon-bone interface at 4 w and 8 w was significantly increased in shockwave, platelet-rich plasma and shockwave+platelet-rich plasma groups. The basic fibroblast growth factor and transforming growth factor beta 1 messenger RNA and protein expression tended to increase after surgery in all four groups and the levels in shockwave, plateletrich plasma and shockwave+platelet-rich plasma groups was significantly increased, while the highest expression in shockwave+platelet-rich plasma group. The maximum load force of the 3 experiment groups was all significantly increased. Besides, the maximum tensile distance was significantly longer in shockwave+platelet-rich plasma group. The combination of extracorporeal shockwave and plateletrich plasma showed optimal performance in the tensile performance of the supraspinatus tendon-bone combination, the maturity of the tendon-bone interface and the content of growth factors that promote the healing of the tendon bone, indicating that the combination of extracorporeal shock wave and plateletrich plasma can promote the healing process of the tendon bone after rotator cuff tears and improve its strength and ultimate load.