Osteochondral Injury can be caused by acute trauma or excessive loading from sports activities, If advanced, it can cause osteoarthritis changes and affect daily activities. The diagnosis and treatment of osteochondral injury is an important musculoskeletal disorder. The treatment of osteochondral injury mainly discuss operation, with less conservative treatment. We here report Extracoporeal Shockwave Therapy ( ESWT ) , could accelerate the repair of osteochondral injury.
Material & Method:
Fifteen 6-week-old pigs were used in the study. The authors made an osteochondral defect model, bilateral femoral medial condyles with 5 × 5 mm2 of cartilage and subchondral bone resected as a single mass. At 2 weeks after surgery, the right knee received 2000 impulses of shockwave at 0.25-mJ/mm2 energy flux density in a single session. The animals were divided into a shockwave group consisting of right knees and a control group consisting of left knees that were not exposed to shockwave impulses. The animals were euthanatized at 8 weeks after surgery, and femur bone including the callus was harvested. The specimens were subjected to macroscopic and histologic examination.
Compared with the control group, macroscopic evaluation showed that the osteochondral defect areas in the shockwave group were more smooth and repairing on the articular cartilage surface. Compared with the control group, histologically, the shockwave group was visualized that the majority of the damaged area was conquered with nearly normal articular cartilage and subchondral bone. Second-harmonic generation ( SHG ) emission is observed when an ultrashort laser pulse is irradiated onto a non-centrosymmetric material, such as collagen. Tissues composed of collagen was evaluated by SHG microscopy. Strong SHG signals were obtained at the histologically recognizable collagen tissues in both groups. In contrast with the control group, most of the damaged area in the shockwave group had been filled with near-normal articular cartilage and subchondral bone.
ESWT accelerated healing of the osteochondral cartilage and subchondral bone in this osteochondral injury model. Although the target of irradiation in ESWT was the damaged subchondral bone, the adjacent osteochondral cartilage was also repaired, suggesting an indirect effect of ESWT.