Noninvasive ultrasound therapy can be useful in the treatment of challenging, established nonunions.

Background and purposeDiscussion persists as to whether obesity negatively influences the outcome of hip arthroplasty. We performed a meta-analysis with the primary research question of whether obesity has a negative effect on short- and long-term outcome of total hip arthroplasty.MethodsWe searched the literature and included studies comparing the outcome of hip arthroplasty in different weight groups. The methodology of the studies included was scored according to the Cochrane guidelines. We extracted and pooled the data. For continuous data, we calculated a weighted mean difference and for dichotomous variables we calculated a weighted odds ratio (OR). Heterogeneity was calculated using I2 statistics.Results15 studies were eligible for data extraction. In obese patients, dislocation of the hip (OR = 0.54, 95% CI: 0.38–0.75) (10 studies, n = 8,634), aseptic loosening (OR = 0.64, CI: 0.43–0.96) (6 studies, n = 5,137), infection (OR = 0.3, CI: 0.19–0.49) (10 studies, n = 7,500), and venous thromboembolism (OR = 0.56, CI: 0.32–0.98) (7 studies, n = 3,716) occurred more often. Concerning septic loosening and intraoperative fractures, no statistically significant differences were found, possibly due to low power. Subjective outcome measurements did not allow pooling because of high heterogeneity (I2 = 68%).InterpretationObesity appears to have a negative influence on the outcome of total hip replacement.

Animal and clinical studies have shown an acceleration of bone healing by the application of low-intensity ultrasound. The objective of this study was to examine in vitro the influence of low-intensity ultrasound on endochondral ossification of 17-day-old fetal mouse metatarsal rudiments.Forty-six triplets of paired metatarsal rudiments were resected 'en block' and cultured for 7 days with and without low-intensity ultrasound stimulation (30 mw/cm2). At days 1, 3, 5, and 7, the total length of the metatarsal rudiments, as well as the length of the calcified diaphysis were measured. Histology of the tissue was performed to examine its vitality.The increase in length of the calcified diaphysis during 7 days of culture was significantly higher in the ultrasoundtreated rudiments compared to the untreated controls ( P = 0.006). The growth of the control diaphysis was 180 f 30 pm (mean i SEM), while the growth of the ultrasound-treated diaphysis was 530 + 120 pm. The total length of the metatarsal rudiments was not affected by ultrasound treatment. Histology revealed a healthy condition of both ultrasound-treated and control rudiments.In conclusion, low-intensity ultrasound treatment stimulated endochondral ossification of fetal mouse metatarsal rudiments. This might be due to stimulation of activity and/or differentiation of osteoblasts and hypertrophic chondrocytes. Our results support the hypothesis that low-intensity ultrasound activates ossification via a direct effect on osteoblasts and ossifying cartilage.

We investigated whether low-intensity pulsed ultrasound (LIPUS) stimulates chondrocyte proliferation and matrix production in explants of human articular cartilage obtained from donors suffering from unicompartimental osteoarthritis of the knee, as well as in isolated human chondrocytes in vitro. Chondrocytes and explants were exposed to LIPUS (30 mW/cm 2 ; 20 min/day, 6 days). Stimulation of [35 S]-sulphate incorporation into proteoglycans by LIPUS was 1.3-fold higher in degenerative than in collateral monolayers as assessed biochemically and 1.9-fold higher in explants as assessed by autoradiography. LIPUS decreased the number of cell nests containing 1-3 chondrocytes by 1.5 fold in collateral and by 1.6 fold in degenerative explants. LIPUS increased the number of nests containing 4-6 chondrocytes by 4.8 fold in collateral and by 3.9 fold in degenerative explants. This suggests that LIPUS stimulates chondrocyte proliferation and matrix production in chondrocytes of human articular cartilage in vitro. LIPUS might provide a feasible tool for cartilage tissue repair in osteoarthritic patients, since it stimulates chondrocyte proliferation and matrix production.