Objectives

Osteoporosis is a chronic disease. The aim of this study was to identify key genes in osteoporosis.

Aims

There is no consensus about the best method of achieving equal leg lengths at total hip arthroplasty (THA) in patients with Crowe type-IV developmental dysplasia of the hip (DDH). We reviewed our experience of a consecutive series of patients who underwent THA for this indication.

We evaluated the impact of lumbar instrumented circumferential fusion on the development of adjacent level vertebral compression fractures (VCFs). Instrumented posterior lumbar interbody fusion (PLIF) has become a popular procedure for degenerative lumbar spine disease. The immediate rigidity produced by PLIF may cause more stress and lead to greater risk of adjacent VCFs. However, few studies have investigated the relationship between PLIF and the development of subsequent adjacent level VCFs.

Between January 2005 and December 2009, a total of 1936 patients were enrolled. Of these 224 patients had a new VCF and the incidence was statistically analysed with other covariants. In total 150 (11.1%) of 1348 patients developed new VCFs with PLIF, with 108 (72%) cases at adjacent segment. Of 588 patients, 74 (12.5%) developed new subsequent VCFs with conventional posterolateral fusion (PLF), with 37 (50%) patients at an adjacent level. Short-segment fusion, female and age older than 65 years also increased the development of new adjacent VCFs in patients undergoing PLIF. In the osteoporotic patient, more rigid fusion and a higher stress gradient after PLIF will cause a higher adjacent VCF rate.

Cite this article: Bone Joint J 2015;97-B:1411–16.

We report a new surgical technique of open carpal tunnel release with subneural reconstruction of the transverse carpal ligament and compare this with isolated open and endoscopic carpal tunnel release.

Between December 2007 and October 2011, 213 patients with carpal tunnel syndrome (70 male, 143 female; mean age 45.6 years; 29 to 67) were recruited from three different centres and were randomly allocated to three groups: group A, open carpal tunnel release with subneural reconstruction of the transverse carpal ligament (n = 68); group B, isolated open carpal tunnel release (n = 92); and group C, endoscopic carpal tunnel release (n = 53).

At a mean final follow-up of 24 months (22 to 26), we found no significant difference between the groups in terms of severity of symptoms or lateral grip strength. Compared with groups B and C, group A had significantly better functional status, cylindrical grip strength and pinch grip strength. There were significant differences in Michigan Hand Outcome scores between groups A and B, A and C, and B and C. Group A had the best functional status, cylindrical grip strength, pinch grip strength and Michigan Hand Outcome score.

Subneural reconstruction of the transverse carpal ligament during carpal tunnel decompression maximises hand strength by stabilising the transverse carpal arch.

Cite this article: Bone Joint J 2015;97-B:221–8

Despite developing refinements of chemotherapy regimens for osteosarcoma, multi-drug resistant cases are frequently seen and patients with metastatic or recurrent disease continue to have a very poor prognosis. Recently, the expression of the longevity gene Sirt1 was found to be relatively higher expressed in tumors compared with the normal tissues. Association of high level of Sirt1 expression with the development of multi-drug resistance in tumor cells has also been indicated. Thus, it is interesting to study the therapeutic potential of regulating Sirt1 activity for the treatment of osteosarcoma.

In the present study, we evaluated the effects of two Sirt1 activators, resveratrol and isonicotinamide, on growth and apoptosis in four human osteosarcoma cell lines, HOS, Saos-2, U-2 OS and MG-63. We found that Sirt1 protein was expressed in all osteosarcoma cell lines. Instead of promoting cell survival, both resveratrol and isonicotinamide decreased cell growth and induced cell apoptosis in a dose-dependent fashion. Furthermore, the pro-apoptotic effect of resveratrol could be enhanced by L-asparaginase-induced nutrition restriction of cultured osteosarcoma cells.

Our results demonstrated that Sirt1 activators elicited pro-apoptotic effects in osteosarcomas. Thus, Sirt1 could be a potential target in the treatment of osteosarcoma. However, due to the non-specificity of the Sirt1 activators used further studies, such as knock-down of Sirt1 by siRNA, are needed to confirm the effect of Sirt1 activation on malignant cells.

Introduction: Alcohol can induce adipogenesis by bone marrow stromal cells and may cause osteonecrosis of the femoral heads. Currently, there are no medications available to prevent alcohol-induced osteonecrosis. The purpose of this study was to evaluate the effects of puerarin on adipocytic differentiation of bone marrow stromal cells and on the prevention of alcohol-induced osteonecrosis.

Materials and Methods: In the in vitro study, bone marrow stromal cells were treated with ethanol as model groups, with ethanol and puerarin as experimental groups, and without ethanol or puerarin to serve as controls. In the in vivo study, model group mice received ethanol intragastrically and normal saline by intramuscular injection. The experimental group received the same dose of alcohol intragastrically and puerarin by intramuscular injection, and the control group received water intragastrically and normal saline by intramuscular injection daily, for 4, 6, 8, and 10 months, respectively.

Results: It was found that in the in vitro experimental group, the number of adipocytes, contents of triglycerides and levels of PPARγ mRNA expression were significantly decreased, and alkaline phosphatase activity, contents of osteocalcin and levels of osteocalcin mRNA expression were significantly increased compared with cells in model groups. In the in vivo experimental group, cholesterol, and triglyceride in serum were significantly decreased, and alkaline phosphatase activity was significantly higher, compared with the model group. Fat cell hypertrophy and proliferation, thinner and sparse trabeculae, diminished hematopoiesis, and increased empty osteocyte lacunae in the subchondral region of the femoral head were observed in the model groups. However, no significant changes were seen in femoral heads of the experimental and the control group.

Discussion: The results showed that puerarin can inhibit adipogenic differentiation by bone marrow stromal cells both in in vitro in cell culture and in vivo animal experiments. These findings indicate that puerarin can prevent alcohol-induced adipogenesis and osteonecrosis.

Purpose: To determine if some subsets of healthy subjects displayed other than a typical gait pattern and to identify which subsets have similar kinematic pattern to patients with knee osteoarthritis.

Methods: The healthy subject dataset consisted of 106 asymptomatic volunteers. These subjects were over 17 years of age, pain-free, had no record of surgery to the lower limb and no evidence or history of arthritic disease at the time of testing. The patient population consisted of 12 patients diagnosed with knee OA, evaluated within 6 months prior to the tests. The 3D movements of right knee joint were recorded using a functional knee analyzer with magnetic sensors while subjects walked on a treadmill at their own preferred speed. The magnetic sensors are non-invasive electromagnetic devices, which track the 3D positions and orientations of sensors relative to a source. The system has been shown to be accurate, especially in the frontal and transversal planes. K-means clustering analysis was chosen to identify the gait patterns among healthy subjects based on three components of the knee joint angles, and analyses of variance were performed to determine which parameters were different between subsets.

Results: Three gait groups or patterns were identified in the healthy subjects. The first group (G1) was characterized by a kinematic profile similar to the OA group. The second group (G2) had the highest external rotation angle, which was significantly different from OA group. The abduction angles were always greater in the G2 and G3 than in the OA group. This might be attributed to a valgus static alignment in G2 and G3 comparing to a varus alignment in the patient with OA.

Conclusions: The newly developed functional knee analyzer provided a non-invasive way to accurately measure 3D kinematic data which enabled cluster analysis to distinguish three gait patterns from 106 healthy subjects. The results suggested a strong correlation between static alignment and dynamic ad-abduction angles during the gait, which need to be investigated. Funding: Other Education Grant Funding Parties: NSERC, CIHR and FCAR

Introduction: Intervertebral disc (IVD) degeneration involves loss of disc matrix leading to instability and pain. Autologous cells are the ideal choice for bioengineering a new IVD, but removal of cells from the IVD is problematic. Our aim was to direct mesenchymal stromal cells (MSCs) down a chondrocytic lineage to mimic disc chondrocyte phenotype.

Methods: MSCs were either maintained in monolayer, pelleted into micromass aggregates or transferred to alginate beads. Pellet cultures were used in immunohis-tochemistry for type II collagen and aggrecan and in situ hybridisation for SOX-9 mRNA. Monolayer and alginate cells were cultured in the presence or absence of chondrogenic medium for 4 and 11 days. Monolayer cultured MSCs were also transfected with a SOX-9 adenovirus and cultured in the presence or absence of TGF-_1. Realtime quantitative PCR was used to analyse expression of chondrocyte markers.

Results: IHC showed increased expression of type II collagen and aggrecan in pellet cultures, while ISH showed that SOX-9 was not expressed by monolayer MSCs, but increased after pelleting. Realtime PCR using alginate-cultured MSCs showed down regulation of type I collagen mRNA expression and up-regulation of SOX-9 that was increased by chondrocgenic medium. SOX-9 transduced monolayer MSCs showed increased type II collagen, aggrecan, SOX-6 and SOX-9 mRNA over controls, while type I collagen levels showed no significant change. Stimulation of transfected MSCs with TGF-_1 showed similar increases in chondrocyte genes.

Discussion & conclusions: Adult human MSCs were induced to differentiate along a chondrocytic phenotype, which was mediated by culture conditions. Alginate and pellet culture produce a cell that has more chondrogenic characteristics than monolayer cells. SOX-9 transduced monolayer MSCs appeared to produce a more chondrocytic phenotype which was modulated by TGF-_1. Results suggest SOX-9 transfected monolayer MSCs may be used as a source of chondrocytes for repair of degenerate IVD.

A four-year-old boy presented with a solitary bone cyst in the odontoid process and body of the axis. Plain radiographs showed a radiolucent lesion with extreme thinning of the cortex and MRI demonstrated a high signal intensity in the interlesional matrix. The cystic component extended into the body of the axis through a defect in the epiphyseal plate.

At operation, the cavity of the cyst was found to contain serosanguineous fluid, and histological examination showed that it was lined by a thin layer of connective tissue. The cyst may have originated from a defect in the epiphyseal plate.