Diagnostic value of open incisional biopsies in suspected, difficult-to-diagnose periprosthetic hip joint infection prior to revision surgery.

INTRODUCTION: Prior to revision of total hip arthroplasty (THA), low-grade chronic periprosthetic joint infection (PJI) is often difficult to diagnose. We aimed to determine the diagnostic accuracy of open incisional tissue biopsy for the prediction of PJI prior to THA revision in cases with culture-negative or dry tap joint aspirates. MATERIALS AND METHODS: This retrospective single-center study includes 32 consecutive THA revision cases with high clinical suspicion of low-grade chronic PJI of the hip with culture-negative or dry tap joint aspirates and without systemic signs of infection. Open incisional biopsy (OIB) was performed prior to revision surgery. Periprosthetic tissue samples were analyzed by microbiology and histopathology for PJI. During definitive revision arthroplasty, identical diagnostics were repeated. Results from both procedures were compared and sensitivity, specificity, positive and negative predictive values of OIB for the final diagnosis were calculated. RESULTS: Average age at revision was 69.3 ± 13.5 years. The sensitivity of the OIB procedure was 80% (microbiology), 69% (histology) and 82% for combined analyses (microbiology and histology). Specificity of OIB was 80% (microbiology), 94% (histology) and 60% for combined analyses. CONCLUSIONS: Open tissue biopsy performed in cases with culture-negative or inconclusive synovial fluid aspirates prior to revision of THA has limited diagnostic accuracy for the prediction of PJI. The procedure does not reliably close the diagnostic gap in a substantial number of cases. In this difficult patient population, risk of an open procedure may outweigh benefits and alternative less invasive methods should be considered for the preoperative diagnosis of PJI.

[Thromboprophylaxis and platelet aggregation inhibitors in spinal surgery: perioperative management]. / Thromboseprophylaxe und Aggregationshemmer in der Wirbelsäulenchirurgie: perioperative Management.

BACKGROUND: The perioperative use of anticoagulants (AC) and platelet aggregation inhibitors (PAI) in the field of spinal surgery suggests an increased rate of epidural bleeding. However, evidence is lacking and these medications are most often indispensable in the prevention of thromboembolic complications. Comprehensive recommendations for the correct use of AC and PAI are lacking. OBJECTIVE: The aim of this study was an analysis of the current situation with regards to the use of AC and PAI in spinal surgery and development of new recommendations. MATERIAL AND METHODS: Two independent surveys on the perioperative use of AC and PAI were obtained from centers for spinal surgery in Germany. The study obtained information on the perioperative use of AC and PAI, risk assessment of thromboembolic and hemorrhagic events as well as on the type and extent of the substance groups used. RESULTS: Almost the entire patient collective (98%) received perioperative low molecular weight heparin. In 64% the medical prophylaxis was started before surgery and in 36% after surgery. The period of prophylaxis was determined arbitrarily. Approximately 40% of interviewees employed paravertebral infiltration and 19% injected into the epidural space in patients on PAI medication. Open spinal canal surgery was performed in 30% of PAI medicated patients and closed spinal canal surgery was executed in 40%. The risk assessment of PAI differed significantly between aspirin and receptor blocker medication as well as dual administration of PAI. DISCUSSION: The use of AC and PAI in spinal surgery in Germany is very heterogeneous and large deviations from the guidelines frequently occurred. Therefore, there is a strong need for further studies to accurately assess the perioperative use of AC and PAI and to formulate precise recommendations.

High fluoride and low calcium levels in drinking water is associated with low bone mass, reduced bone quality and fragility fractures in sheep.

UNLABELLED: Chronic environmental fluoride exposure under calcium stress causes fragility fractures due to osteoporosis and bone quality deterioration, at least in sheep. Proof of skeletal fluorosis, presenting without increased bone density, calls for a review of fracture incidence in areas with fluoridated groundwater, including an analysis of patients with low bone mass. INTRODUCTION: Understanding the skeletal effects of environmental fluoride exposure especially under calcium stress remains an unmet need of critical importance. Therefore, we studied the skeletal phenotype of sheep chronically exposed to highly fluoridated water in the Kalahari Desert, where livestock is known to present with fragility fractures. METHODS: Dorper ewes from two flocks in Namibia were studied. Chemical analyses of water, blood and urine were executed for both cohorts. Skeletal phenotyping comprised micro-computer tomography (µCT), histological, histomorphometric, biomechanical, quantitative backscattered electron imaging (qBEI) and energy-dispersive X-ray (EDX) analysis. Analysis was performed in direct comparison with undecalcified human iliac crest bone biopsies of patients with fluoride-induced osteopathy. RESULTS: The fluoride content of water, blood and urine was significantly elevated in the Kalahari group compared to the control. Surprisingly, a significant decrease in both cortical and trabecular bones was found in sheep chronically exposed to fluoride. Furthermore, osteoid parameters and the degree and heterogeneity of mineralization were increased. The latter findings are reminiscent of those found in osteoporotic patients with treatment-induced fluorosis. Mechanical testing revealed a significant decrease in the bending strength, concurrent with the clinical observation of fragility fractures in sheep within an area of environmental fluoride exposure. CONCLUSIONS: Our data suggest that fluoride exposure with concomitant calcium deficit (i) may aggravate bone loss via reductions in mineralized trabecular and cortical bone mass and (ii) can cause fragility fractures and (iii) that the prevalence of skeletal fluorosis especially due to groundwater exposure should be reviewed in many areas of the world as low bone mass alone does not exclude fluorosis.

The cytotoxic effects of three different bisphosphonates in-vitro on human gingival fibroblasts, osteoblasts and osteogenic sarcoma cells.

INTRODUCTION: Osteonecrosis of the jaw (ONJ) is an emerging condition in patients undergoing long-term administration of bisphosphonates (BP) for the treatment of osteoporosis and hypercalcaemia associated with malignancy, multiple myeloma, and metastatic breast and prostate cancers. This is a follow-up study, its purpose was to examine the effects in-vitro of intravenous zoledronic acid (ZOL) and pamidronate (PAM) and oral alendronate (FOS) on the human oral cavity using gingival fibroblasts and osteoblasts cells and, in addition, osteogenic sarcoma cells (SaOS-2-cells). MATERIALS AND METHODS: Human gingival fibroblasts, osteoblasts and SaOS-2-cells were seeded on multiple 6-well plates at a density of 5 × 10(5)cells in a 4-week cell culture. Four different concentrations (1, 5, 10, 20 µM) of each BP (ZOL, PAM, FOS) and pyrophosphate were used in this study. RESULTS: All BP decreased collagen production and lowered cell proliferation in-vitro. ZOL was the component with most inhibitory effect. CONCLUSION: The findings in this study suggest that ZOL, PAM and FOS generally diminish cell proliferation and collagen production of human gingival fibroblasts, osteoblasts and SaOS-2-cells. The present follow-up study shows that not only ZOL and PAM but also FOS have a strong inhibitory effect on collagen production and cell survival in-vitro.