Therapeutic effects of whole-body vibration on fracture healing in ovariectomized rats: a systematic review and meta-analysis

OBJECTIVE

Whole-body vibration (WBV), providing cyclic mechanical stimulation, has been used to accelerate fracture healing in preclinical studies. This study aimed to summarize and evaluate the effects of WBV on bone healing in ovariectomized rat models and then analyze its potential effects on fractures in human postmenopausal osteoporosis.

METHODS

PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure, VIP, SinoMed, and WanFang databases were searched from their inception date to September 2017, and an updated search was conducted in January 2018. Studies that evaluated the effects of WBV on bone healing compared with control groups in ovariectomized rats were included. Two authors selected studies, extracted data, and assessed the methodological quality. Meta-analyses were performed when the same outcomes were reported in two or more studies.

RESULTS

Nine eligible studies were selected. In treatment groups, callus areas were significantly improved in the first 3 weeks, normalized total bone volume and total tissue volume values increased dramatically at 8 weeks, and the mechanical tests showed a significant difference at the end point of the study.

CONCLUSIONS

This study suggested that WBV could accelerate callus formation in the early phase of bone healing, promote callus mineralization and maturity in the later phase, and restore mechanical properties of bones.

Carbonate Apatite Containing Statin Enhances Bone Formation in Healing Incisal Extraction Sockets in Rats

The purpose of this study was to evaluate the feasibility of using apatite blocks fabricated by a dissolution⁻precipitation reaction of preset gypsum, with or without statin, to enhance bone formation during socket healing after tooth extraction. Preset gypsum blocks were immersed in a Na₃PO₄ aqueous solution to make hydroxyapatite (HA) low crystalline and HA containing statin (HAFS), or in a mixed solution of Na₂HPO₄ and NaHCO₃ to make carbonate apatite (CO) and CO containing statin (COFS). The right mandibular incisors of four-week-old male Wistar rats were extracted and the sockets were filled with one of the bone substitutes or left untreated as a control (C). The animals were sacrificed at two and four weeks. Areas in the healing socket were evaluated by micro-computed tomography (micro-CT) and histological analyses. The bone volume, trabecular thickness, and trabecular separation were greatest in the COFS group, followed by the CO, HAFS, HA, and C groups. The bone mineral density of the COFS group was greater than that of the other groups when evaluated in the vertical plane. The results of this study suggest that COFS not only allowed, but also promoted, bone healing in the socket. This finding could be applicable for alveolar bone preservation after tooth extraction.

Radiographic and Histological Evaluation of the Healing of Extraction Sockets Filled With Bovine-Derived Xenograft: An Experimental Study in Rats

AIM

To evaluate the microenvironment changes in the sockets substituted with bovine-derived xenografts during the early healing period.

MATERIALS AND METHODS

After extraction of the right maxillary incisor of Sprague Dawley rats, 48 rats were randomly divided into 2 groups. The extraction sockets of the test group were filled with Bio-Oss, whereas the control group was allowed to heal without intervention. The bone quality of the extraction sockets was observed through micro-CT and immunohistochemistry.

RESULTS

Micro-CT scanning showed that the bone mineral density in the test group was significantly higher than that in the control group during the early healing period, whereas immunohistochemistry showed that the bone formation-related factors were significantly different between the test and control groups.

CONCLUSIONS

The bovine-derived xenografts may interfere with the healing process of the extraction socket in the early healing stage. Bone formation of the extraction socket was delayed after grafting with bone substitute.

The effect of local application of low-magnitude high-frequency vibration on the bone healing of rabbit calvarial defects-a pilot study

Background

The objective of this pilot study was to evaluate the effect of local application of low-magnitude high-frequency vibration (LMHFV) on the bone healing of rabbit calvarial defects that were augmented with different grafting materials and membranes.

Methods

Four calvarial defects were created in each of two New Zealand rabbits and filled with the following materials: biphasic calcium phosphate (BCP), deproteinized bovine bone mineral covered with a non-cross-linked collagen membrane (BO/BG), biphasic calcium phosphate covered with a strontium hydroxyapatite-containing collagen membrane (BCP/SR), and non-cross-linked collagen membrane (BG). Four defects in one rabbit served as a control, while the other was additionally subjected to the local LMHFV protocol of 40 Hz, 16 min per day. The rabbits were sacrificed 1 week after surgery. Histomorphometric analysis was performed to determine the percentages of different tissue compartments.

Results

Compared to the control defects, the higher percentage of osteoid tissue was found in LMHFV BG defects (35.3 vs. 19.3%), followed by BCP/SR (17.3 vs. 2.0%) and BO/BG (9.3 vs. 1.0%). The fraction occupied by the residual grafting material varied from 40.3% in BO/BG to 22.3% in BCP/SR LMHFV defects. Two-way models revealed that material type was only significant for the osteoid (P= 0.045) and grafting material (P = 0.001) percentages, while the vibration did not provide any statistical significance for all histomorphometric outcomes (P > 0.05).

Conclusion

Local application of LMHFV did not appear to offer additional benefit in the initial healing phase of rabbit calvarial defects. Histomorphometric measurements after 1 week of healing demonstrated more pronounced signs of early bone formation in both rabbits that were related with material type and independent of LMHFV.