Extracorporeal shock wave therapy improves motor dysfunction and pain originating from knee osteoarthritis in rats.
OBJECTIVE
Although there have been several reports on the use of extracorporeal shock wave therapy (ESWT), the efficacy of ESWT for knee osteoarthritis (OA) has not been clarified. The aim of this study is to investigate the effect of ESWT on OA in a rat knee model.


METHODS
The rats were divided into three groups: (1) control, (2) OA, and (3) ESWT (knee OA+shock wave therapy). Behavioral analysis consisted of measuring the duration of walking on a treadmill. The expression of calcitonin gene-related peptide (CGRP) in dorsal root ganglion (DRG) neurons innervating the knee using immunohistochemistry was examined in the three groups at their peak time point on the treadmill.


RESULTS
Walking duration was significantly extended 4, 7 and 14 days after ESWT in rats with knee OA (peak time point: 4 days), again decreasing by days 21 and 28. Immunohistochemical studies revealed that the OA group had significantly higher percentages of CGRP positive neurons in the DRG than were found in the control group. In addition, ESWT reduced the ratio of CGRP positive DRG neurons in the OA model.


CONCLUSIONS
The improvement in walking ability and the reduction of CGRP positive neurons in DRG indicates that ESWT is a useful treatment for knee OA.
Ochiai
N
N
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Japan. nobunobu1215@yahoo.co.jp
Ohtori
S
S
Sasho
T
T
Nakagawa
K
K
Takahashi
K
K
Takahashi
N
N
Murata
R
R
Takahashi
K
K
Moriya
H
H
Wada
Y
Y
Saisu
T
T
D000704:Analysis of Variance; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D004195:Disease Models, Animal; D005727:Ganglia, Spinal / Q000737:chemistry*; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D007150:Immunohistochemistry; D008297:Male; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000628:therapy*; D059408:Pain Management; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin
D015740:Calcitonin Gene-Related Peptide