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


OBJECTIVE
Low-dose ESW might have a healing enhancement effect comparable to that of high-dose ESW in treating delayed TBI healing.


METHODS
Controlled laboratory study.


METHODS
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.


RESULTS
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.


CONCLUSIONS
Extracorporeal shockwave, a unique noninvasive physical modality, had similar effects between the low and high dose for treating delayed TBI healing.


CONCLUSIONS
Low-dose ESW for TBI delayed healing might be more desirable and have better compliance in clinical applications.
Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
Dick Ho Kiu
DH
Chow
Pui Kit
PK
Suen
Lai Hong
LH
Fu
Wing Hoi
WH
Cheung
Kwok Sui
KS
Leung
Margaret Wan Nar
MW
Wong
Ling
L
Qin
D000818:Animals; D005260:Female; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D007596:Joints / Q000473:pathology*; D007869:Leg Injuries / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D011817:Rabbits; D011859:Radiography; D013709:Tendon Transfer; D014945:Wound Healing