Low magnitude high frequency vibration accelerated cartilage degeneration but improved epiphyseal bone formation in anterior cruciate ligament transect induced osteoarthritis rat model.
OBJECTIVE
To evaluate the effects of low-magnitude high-frequency vibration (LMHFV) on degenerated articular cartilage and subchondral bone in anterior cruciate ligament transection (ACLT) induced osteoarthritis (OA) rat model.


METHODS
6 months old female Sprague-Dawley rats received ACLT on right knee and randomly divided into treatment and control groups. OA developed 12 weeks after surgery. LMHFV (35 Hz, 0.3 g) treatment was given 20 min/day and 5 days/week. After 6, 12 and 18 weeks, six rats of each group were sacrificed at each time point and the right knees were harvested. OA grading score, distal femur cartilage volume (CV), subchondral bone morphology, elastic modulus of cartilage and functional changes between groups were analyzed.


RESULTS
Increased cartilage degradation (higher OA grading score) and worse functional results (lower duty cycle, regular index and higher limb idleness index) were observed after LMHFV treatment (P = 0.011, 0.020, 0.012 and 0.005, respectively). CV increased after LMHFV treatment (P = 0.019). Subchondral bone density increased with OA progress (P < 0.01). Increased BV/TV, Tb.N and decreased Tb.Sp were observed in distal femur epiphysis in LMHFV treatment group (P = 0.006, 0.018 and 0.011, respectively).


CONCLUSIONS
LMHFV accelerated cartilage degeneration and caused further functional deterioration of OA affected limb in ACLT-induced OA rat model. In contrast, LMHFV promoted bone formation in OA affected distal femur epiphysis, but did not reverse OA progression.
Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: Jianghui.qin@gmail.com.
J
J
Qin
Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: skhchow@ort.cuhk.edu.hk.
S K-H
SK
Chow
Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: anyunguo2011@hotmail.com.
A
A
Guo
Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: mwnwong@gmail.com.
W-N
WN
Wong
Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: ksleung@cuhk.edu.hk.
K-S
KS
Leung
Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region. Electronic address: louis@ort.cuhk.edu.hk.
W-H
WH
Cheung
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D004195:Disease Models, Animal; D018450:Disease Progression; D004838:Epiphyses / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006132:Growth Plate / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D010003:Osteoarthritis / Q000209:etiology* / Q000473:pathology* / Q000503:physiopathology; D010012:Osteogenesis / Q000502:physiology*; D010812:Physical Stimulation / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D013997:Time Factors; D014732:Vibration / Q000009:adverse effects*; D055114:X-Ray Microtomography
Knee osteoarthritis; Low-magnitude high-frequency vibration; Mechanical stimulation; Subchondral bone