The Effect of Vibration Treatments Combined with Teriparatide or Strontium Ranelate on Bone Healing and Muscle in Ovariectomized Rats

Abstract

The aim of the present study was to study the effect of combined therapy of teriparatide (PTH) or strontium ranelate (SR) with whole-body vibration (WBV) on bone healing and muscle properties in an osteopenic rat model. Seventy-two rats (3 months old) were bilaterally ovariectomized (Ovx), and 12 rats were left intact (Non-Ovx). After 8 weeks, bilateral transverse osteotomy was performed at the tibia metaphysis in all rats. Thereafter, Ovx rats were divided into six groups (n = 12): (1) Ovx-no treatment, (2) Ovx + vibration (Vib), (3) SR, (4) SR + Vib, (5) PTH, and (6) PTH + Vib. PTH (40 μg/kg BW sc. 5×/week) and SR (613 mg/kg BW in food daily) were applied on the day of ovariectomy, vibration treatments 5 days later (vertical, 70 Hz, 0.5 mm, 2×/day for 15 min) for up to 6 weeks. In the WBV + SR group, the callus density, trabecular number, and Alp and Oc gene expression were decreased compared to SR alone. In the WBV + PTH group, the cortical and callus widths, biomechanical properties, Opg gene expression, and Opg/Rankl ratio were increased; the cortical and callus densities were decreased compared to PTH alone. A case of non-bridging was found in both vibrated groups. Vibration alone did not change the bone parameters; PTH possessed a stronger effect than SR therapy. In muscles, combined therapies improved the fiber size of Ovx rats. WBV could be applied alone or in combination with anti-osteoporosis drug therapy to improve muscle tissue. However, in patients with fractures, anti-osteoporosis treatments and the application of vibration could have an adverse effect on bone healing.

A systematic review of current osteoporotic metaphyseal fracture animal models

“…The most commonly used osteoporotic metaphyseal fracture model was the bilateral osteotomy on the proximal tibia of ovariectomized rats, originated by Stuermer et al, 10 which was used by 11 published studies. 10 , 25 - 31 , 33 , 34 , 36 All 11 studies that used the bilateral osteotomy model investigated potential therapeutic drugs or noninvasive interventions. The unilateral complete osteotomy was used to investigate potential therapeutic agents to promote osteoporotic fracture healing.…”

“…All 12 complete osteotomy models in this review had appropriate osteoporotic induction and complete discontinuity of bone during the osteotomy. However, the 11 studies by Stuermer et al, 10 , 27 , 28 , 33 Kolios et al, 25 , 26 , 29 and Komrakova et al 30 , 31 , 34 , 36 performed bilateral proximal osteotomies on rats. Complete osteotomies are clinically relevant, but it is rare that both limbs are affected in clinical cases.…”

Could whole body vibration exercises influence the risk factors for fractures in women with osteoporosis?

“…Several mechanisms are cited to be involved in decreasing the rate of fracture healing due to decreased quality of bone, like altered cell recruitment and angiogenesis [8] . The mechanical stimulation may also not be adequately absorbed due to delayed osteogenic capacity in these osteoporotic bones.…”

“…The mechanical stimulation may also not be adequately absorbed due to delayed osteogenic capacity in these osteoporotic bones. But although the time of healing may be different, the regenerative process is considered to be the same, independently of the quality of the bone [8] . It was also demonstrated effects on estrogen receptors that are directly related to fracture healing in ovariectomized osteoporotic rats [9] .…”

“…In studies with rats, it was demonstrated that low-magnitude high-frequency vibration (LMHFV) is an intervention that may act as bone quality enhancer in ovariectomized rats, including positive effects in bone biomarkers like osteocalcin and alkaline phosphatase and improvement in callus formation [8] .…”