Enhancing mechanical strength during early fracture healing via shockwave treatment: an animal study.
OBJECTIVE
This investigation aims to determine (1) whether shockwave treatment helps fracture healing and (2) whether the effect of shockwave treatment on fracture healing is dose dependent.


METHODS
Shockwave was applied over tibial osteotomy in an animal model to assess its effect on the healing of the fracture.


METHODS
Bilateral tibial diaphyseal transverse osteotomy was conducted on 42 rabbits, dividing into experimental and control group, immobilized using an external skeletal fixator, with one leg tested with shockwave therapy and the contralateral leg acting as the control without therapy. Serial radiography and measurement of bone mineral density via dual-energy X-ray absorptiometry were performed to assess the fracture healing. The experimental animals had two or three sessions of shockwave therapy (5000 impulses, 0.32 mJ/mm(2), Orthopedic) over the osteotomy sites on day 7, 21 and 35; while the control group did not receive any treatment. The animals were sacrificed on day 42 or 56. Then, bilateral tibias were harvested and sent for mechanical tests as well as the histological examination. The pertinent statistic methods were applied to analyze the results.


BACKGROUND
Shockwave therapy has become a useful alternative approach in treating various orthopedic conditions, but the mechanism which it works remains unclear. Thus far, shockwave therapy has been found effective in treating long bone pseudoarthrosis, but whether it can benefit fresh fracture healing continues to be debated.


RESULTS
Higher union rates occurred during the early but not the late stages in the experimental group, while mechanical strength was higher in the experimental group than in the control group. No significant dose-dependent response occurred between the second and third applications of shockwave treatment. No significant difference in mechanical strength occurred between the experimental groups at 4 weeks and the control group at 6 weeks, or between the experimental groups at 6 and 8 weeks. Furthermore, no significant correlation occurred between the absolute values of maximum torque and bone mineral density.


CONCLUSIONS
Based on this investigation, shockwave treatment has a positive effect on early fracture healing while its long term effects require further investigation.


CONCLUSIONS
Shockwave therapy can be a useful alternative adjunct modality in the treatment of fresh long bone fracture.
Hsu
Robert Wen-Wei
RW
Department of Orthopaedics, Chang Gung Memorial Hospital, Chang Gung Medical College, Chang Gung University, No. 6, West Section, Chia-Pu Road, Putz, Chia-yi, Taiwan, ROC. orthboss@cgmh.org.tw
Tai
Ching-Lung
CL
Chen
Chris Yu-Chih
CY
Hsu
Wei-Hsiu
WH
Hsueh
Swei
S
D015502:Absorptiometry, Photon; D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density; D002146:Bony Callus / Q000473:pathology; D004307:Dose-Response Relationship, Radiation; D017102:Fracture Healing / Q000502:physiology* / Q000528:radiation effects; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D008297:Male; D011817:Rabbits; D011897:Random Allocation; D013978:Tibial Fractures / Q000503:physiopathology / Q000532:radiotherapy*