Extracorporeal shockwave therapy for treatment of delayed tendon-bone insertion healing in a rabbit model: a dose-response study

• Published in: The American journal of sports medicine Vol. 40; no. 12; p. 2862
• Main Authors: Chow, Dick Ho Kiu, Suen, Pui Kit, Fu, Lai Hong, Cheung, Wing Hoi, Leung, Kwok Sui, Wong, Margaret Wan Nar, Qin, Ling
• Format: Journal Article
• Language: English
• Published: United States 01.12.2012
• Subjects: Animals; Female; High-Energy Shock Waves - therapeutic use; Joints - pathology; Leg Injuries - diagnostic imaging; Leg Injuries - pathology; Leg Injuries - therapy; Rabbits; Radiography; Tendon Transfer; Wound Healing
• ISSN: 1552-3365
• DOI: 10.1177/0363546512461596

Tendon-bone insertion (TBI) consists of both hard and soft tissues. TBI injury with delayed repair is not uncommon. High-dose extracorporeal shockwave (ESW) is effective for treating nonunion fracture, whereas low-dose ESW is used for tendinopathy therapy. The dosing effect of ESW on delayed TBI healing is lacking. Low-dose ESW might have a healing enhancement effect comparable to that of high-dose ESW in treating delayed TBI healing. Controlled laboratory study. Partial patellectomy was adopted to create a delayed TBI healing model by shielding the healing interface between tendon and bone. Ninety-six female New Zealand White rabbits with unilateral delayed TBI healing at the knee joint were divided into 3 groups: controls, low-dose ESW (LD-ESW; 0.06 mJ/mm(2), 4 Hz, 1500 impulses), and high-dose ESW (HD-ESW; 0.43 mJ/mm(2), 4 Hz, 1500 impulses). The TBI shielding was removed at week 4 after partial patellectomy, followed by treatment with control or ESW at week 6. The rabbits were euthanized at week 8 and week 12 for radiological, microarchitectural, histological, and mechanical assessments of healing tissues. Radiologically, both the LD-ESW group and the HD-ESW group showed larger new bone area than the controls at week 8 and week 12. Microarchitectural measurements showed that the LD-ESW and HD-ESW groups had larger new bone volume than the controls at week 12. Histological assessments confirmed osteogenesis enhancement. Both the LD-ESW and HD-ESW groups showed significantly higher failure load at the TBI healing complex than the control group at week 12. No significant difference was detected between the 2 ESW treatment groups at week 8 or week 12. Extracorporeal shockwave, a unique noninvasive physical modality, had similar effects between the low and high dose for treating delayed TBI healing. Low-dose ESW for TBI delayed healing might be more desirable and have better compliance in clinical applications.