BackgroundSubtrochanteric femoral shortening osteotomy is a crucial procedure to prevent nerve injury in total hip arthroplasty for severe developmental dysplasia of the hip. Transverse osteotomy was first applied, and other modified methods have also been reported. Each has its own advantages and limitations, but no definitive conclusions regarding differences in outcomes have been reached to date.MethodsWe therefore performed a comprehensive meta-analysis to compare the outcomes of different approaches. 37 studies (795 hips) were included in the final analysis. Meta-analysis, subgroup analysis and meta-regression were performed.ResultsMeta-analysis and subgroup analysis showed no significant difference between transverse and modified method. This is further confirmed by meta-regression. Method of osteotomy was found to be not associated with nonunion rate (P = 0.472), as well as other post-operative outcomes including nerve palsy (P = 0.240), dislocation (P = 0.735), revision (P = 0.653) and Harris hip score improvement (P = 0.562). In addition, western countries (P = 0.010) and duration of follow-up more than 5 years (P = 0.014) were associated with higher revision rate.ConclusionsTransverse osteotomy and modified osteotomy appear to be equivalent in terms of nonunion, safety and efficacy. Transverse osteotomy may be recommended, due to its simplicity and convenience in adjusting the anteversion angle. Well-designed and large-sample-size randomized controlled trials are expected to confirm and update the findings of this analysis.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2474-15-331) contains supplementary material, which is available to authorized users.

Aseptic loosening (AL) caused by wear particles released from implant surfaces is one of the main causes for the failure of artificial joints, which is initiated by macrophage inflammatory responses.

Arthroplasty has been widely performed worldwide. However, peri-prosthetic osteolysis and aseptic loosening induced by macrophages activated by wear particles still remain a predominant cause of long term prosthetic failure. Our study aimed to identify the role of small heterodimer partner (SHP) in secretion of proinflammatory cytokines by macrophages through Toll-like Recepters (TLR)s signaling pathway activated by wear particles both in vivo and in vitro. The effect of SHP on activation of TLR4 pathway and secretion of cytokines was observed in RAW264.7 cells and SHP gene over-expressed mice. Expression of TLR4, TRAF6, NEMO complex and proinflammatory cytokine TNF-α in macrophages stimulated by wear particles was up-regulated, while SHP was down-regulated. On the other hand, inhibition of SHP up-regulated the expression of NEMO complex and proinflammatory cytokine TNF-α in RAW264.7 stimulated by wear particles, while over-expression of SHP gene showed an opposite result. Over-expression of SHP gene could inhibit cranial osteolysis induced by wear particles in mice model. In conclusion, SHP down-regulates TLR4 signaling pathway to reduce osteolysis induced by titanium particles via in vitro and in vivo experimental models.

The novel surgical technique enhanced post-operative rehabilitation by providing better ankle joint function than modified Broström procedure at 12 months after operation, while the advantage was not statistically significant 30 months later. The long-term outcome requires further investigation. The technique of all-arthroscopic anatomical ATFL reconstruction using semitendinosus autografts proved to be a viable option for ATFL injuries.

SummaryBackgroundPolylactic acid polymer interference screws are commonly used in anterior cruciate ligament (ACL) reconstructions, especially in proximal tibia fixation. However, several concerns have been raised, including the acid products during its degradation in vivo. In recent years, biodegradable magnesium (Mg)-based implants have become attractive because of their favourable mechanical properties, which are more similar to those of natural bone when compared with other degradable materials, such as polymers, apart from their alkaline nature during degradation.MethodsWe developed a pure Mg interference screw for ACL reconstruction. In the present study, 24 fresh cadaver knees were used to compare the mechanical properties of pure Mg interference screws and polylactic acid polymer interference screws for ACL reconstruction via their application on the proximal tibia tested using specific robotics.ResultsResults showed that the pure Mg interference screw group showed similar mechanical stability to the polylactic acid polymer interference screw group, implying comparable postoperative fixation effects.ConclusionAs there are no commercially available Mg-based interference screws for ACL reconstruction clinically and the in vivo degradation of pure Mg promotes bone formation, our cadaveric study supports its clinical tests for ACL reconstruction.

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Aseptic loosening due to wear particle‐induced osteolysis is the main cause of arthroplasty failure and the influence of postmenopausal osteoporosis and anti‐osteoporosis treatment on Titanium (Ti) particle‐induced osteolysis remains unclear. 66 C57BL/6J female mice were used in this study. Ovariectomy (OVX) was performed to induce osteopenia mice and confirmed by micro‐CT. The Ti particle‐induced mouse calvaria osteolysis model was established subsequently and both OVX and Sham‐OVX mice were divided into four groups, respectively: Ti (‐) group, Ti group, Ti + zoledronic acid (ZOL) group (50ug/kg, local administration, single dose) and Ti + teriparatide (TPTD) group (40ug/kg/d, subcutaneous injection*14d). Mice calvarias were collected for micro‐CT and histomorphometric analysis 2 weeks after particle induction. 8 weeks after bilateral OVX, significantly reduced BMD and microstructure parameters in both proximal tibia and calvaria were observed in OVX mice when comparing with Sham‐OVX mice. OVX mice in Ti group had not only markly decreased BMD and BV/TV, but also significantly increased total porosity, eroded surface area and osteoclast numbers when comparing with Sham‐OVX mice. Shown by Two‐way ANOVA analysis, the interaction terms between OVX and Ti implantation on micro‐CT and histomorphometry parameters didn’t reach significant difference. As illustrated by micro‐CT and histological analysis, ZOL treatment markedly inhibited Ti particle‐induced osteolysis in OVX mice and Sham‐OVX mice, and there were significant differences when comparing to both Ti and Ti+TPTD group. The combination of osteoporosis and Ti particle implantation result in aggravated bone resorption, accompanied with increased osteoclasts and excessive inflammation response. ZOL was more effective in preventing Ti particle‐induced osteolysis in both OVX mice and Sham‐OVX mice than TPTD in short‐term administration. ZOL exert the protective effects on Ti particle‐induced bone loss via the suppression of osteoclasts.

NOD2 protects mice from titanium particle-induced osteolysis.