[Patient safety during endoprosthetic training : Does the training of surgeons in primary hip arthroplasty at certified endoprosthesis centres lead to increased complications?] / Patientensicherheit in der endoprothetischen Weiterbildung : Führt die Weiterbildung von Operateuren in der primären Hüftgelenkendoprothetik in zertifizierten Endoprothesenzentren zu vermehrten Komplikationen?

BACKGROUND: The aim of the study was to investigate whether the perioperative outcome and the operation-specific process variables in patients with total hip arthroplasty (THA) significantly deteriorate when the operation is performed by an inexperienced surgeon assisted by an experienced one in the context of a certified endoprosthesis center. MATERIAL AND METHODS: 1480 patients who received primary THA for primary coxarthrosis between 2013 and 2016 were included. The relevant data were retrospectively documented from the hospital information system, the discharge letter and the EndoCert form. The surgeons were divided according to their qualifications into experienced (senior surgeon, > 50 THA per year) and inexperienced surgeons (junior surgeon, < 50 THA per year). The collected data and measured variables were then compared based on this subdivision. RESULTS: Inexperienced surgeons showed a significant increase in the duration of the operation by 20.7 min (senior 62.6 ± 20.4 min; junior 83.3 ± 19.5 min; p ≤ 0.001), as well as the length of hospital stay by 0.25 days (senior 8.8 ± 0.9 days; junior 9.0 ± 0.9 days; p ≤ 0.001). The frequency of transfusions of red cell concentrates was significantly increased with inexperienced surgeons (senior 0.6 ± 1.1 items; junior 0.9 ± 1.4 items; p ≤ 0.001). In contrast, there was no difference in perioperative complications (p = 0.682) or in perioperative blood loss (senior 1.3 ± 0.5 l; junior 1.3 ± 0.5 l; p = 0.097). However, there was a positive correlation between the duration of the operation and blood loss (senior r = 0.183; junior r = 0.214; each p ≤ 0.01). CONCLUSION: The training of inexperienced surgeons at a certified endoprosthesis center does not lead to a reduction in patient safety or increased complications when inexperienced surgeons are assisted by experienced surgeons. Due to the extended operating time, however, there is an additional burden on the clinics in competition with non-training clinics, which is not mapped in the DRG system.

Tungsten accumulates in the intervertebral disc and vertebrae stimulating disc degeneration and upregulating markers of inflammation and pain.

Tungsten is incorporated in many industrial goods, military applications and medical devices due to its ability to impart flexibility, strength and conductance to materials. Emerging evidence has questioned the safety of tungsten exposure as studies have demonstrated it can promote tumour formation, induce pulmonary disease and alter immune function. Although tungsten is excreted from the body it can accumulate in certain organs such as the brain, colon, liver, kidneys, spleen and bones, where most of the bioaccumulation occurs. Whether prolonged tungsten exposure leads to accumulation in other tissues is unknown. The present study demonstrated that mice exposed to 15 ppm sodium tungstate for 4 weeks in their drinking water showed comparable accumulation in both the bony vertebrae and intervertebral discs (IVDs). Lumbar IVD height was significantly reduced in tungsten-exposed mice and accompanied by decreased proteoglycan content and increased fibrosis. In addition to catabolic enzymes, tungsten also increased the expression of the inflammatory cytokines IL-1ß and tumour necrosis factor (TNF)-α as well as the neurotrophic factors nerve growth factor (NGF) and brain-derived nerve factor (BDNF) in IVD cells. Tungsten significantly increased the presence of nociceptive neurons at the endplates of IVDs as observed by the expression of calcitonin gene-related peptide (CGRP) and anti-protein gene product 9.5 (PGP9.5) in endplate vessels. The present study provided evidence that tungsten may enhance disc degeneration and fibrosis as well as increase the expression of markers for pain. Therefore, tungsten toxicity may play a role in disc degeneration disease.

Sodium hypochlorite is more effective than chlorhexidine for eradication of bacterial biofilm of staphylococci and Pseudomonas aeruginosa.

PURPOSE: Periprosthetic infection is a common reason for surgical revision. Given the increasing resistance of bacteria to antibiotics (e.g., VRE, 4-MRGN) local antiseptic treatment is gaining in importance. However, no standard guideline-based treatment recommendation is yet available. The aim of this study was to investigate the effectiveness of sodium hypochlorite and chlorhexidine against bacterial biofilms. Furthermore, the toxicity of both antiseptics towards human chondrocytes was examined. METHODS: Human chondrocytes were isolated, cultivated and treated with sodium hypochlorite and chlorhexidine. The viability of cultures was assessed by determination of cell count, XTT and MTT ELISAs, and fluorescent staining with propidium iodide. Bacterial strains of Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa were added to liquid media and incubated overnight. After determination of bacterial concentrations polyethylene (PE) devices were inoculated with bacteria for 48 h until biofilms formed. The devices were then washed, treated with antiseptics for 2 and 5 min and subsequently spread on agar plates. RESULTS: Sodium hypochlorite is more effective than chlorhexidine in penetrating biofilms of S. aureus, S. epidermidis and P. aeruginosa. Both antiseptics are chondrotoxic, but sodium hypochlorite damages human chondrocytes less than chlorhexidine in vitro. CONCLUSIONS: The findings confirm the effectiveness of sodium hypochlorite and chlorhexidine against bacterial biofilms. Both antiseptics can be recommended for the treatment of periprosthetic infections. The toxic effects of sodium hypochlorite and chlorhexidine towards chondrocytes may mean there is a risk of damage to cartilage tissue. LEVEL OF EVIDENCE: Controlled experimental study.

[Implantation of a tantalum patella during revision surgery]. / Implantation einer Tantalpatella in der Revision.

OBJECTIVE: The reconstruction or restoration of a functioning patella for active extension and flexion by implantation of a tantalum patella. In spite of larger osseous defects of the patella, the goal is to achieve sufficient extensor mechanism function. INDICATIONS: Patients who have such a large bone defect in the area of the patella that implantation of a traditional patella replacement is not possible. In addition, patients with a peri-implant fracture of the patella can be treated with a tantalum patella and additional plate osteosynthesis. CONTRAINDICATIONS: Absence of a cortical basic structure of the patella. Complete loss of the patella or the extensor mechanism. Periprosthetic infection. SURGICAL TECHNIQUE: The patella is completely excised. Subsequently, the back surface of the patella is milled to anchor the tantalum structure as accurately as possible without cement. This is fixed circularly after desired positioning by means of nonresorbable suture. Finally, the polyethylene back surface replacement is cemented onto the back surface of the tantalum structure. POSTOPERATIVE MANAGEMENT: The patients have a limitation of flexion of 0-0-90° at 20 kilogram partial weight bearing for 12 weeks after surgery. RESULTS: A total of 10 patients who received a tantalum patella between 2013 and 2019 were retrospectively included. A tantalum patella was implanted in 9 patients with a large patellar defect. In one case a tantalum patella with additional plate osteosynthesis was implanted to treat a peri-implant fracture of the patella. Loosening of the tantalum patella was observed in 1 patient, while in another patient postoperative arthrofibrosis was observed. In 2 cases a postoperative superficial wound healing disorder was detected. Two patients had a persistent infection with subsequent complete explantation of the prosthesis.