Objective In orthopedic joint injection, the most frequently used local anesthetics are ropivacaine, bupivacaine, and 1% or 2% lidocaine. The aim of this study was to examine effects of these various anesthetics on the viability of human chondrocytes. Our hypothesis was that all local anesthetics tested damage human chondrocytes in vitro. Methods Primary human chondrocytes were isolated and cultured from 6 donated human knee joints (mean age of donors 61.2 years). Local anesthetics were added to these cultures. Toxicity analysis was performed by visualization of cell structure using light microscopy. Determination of vital chondrocytes was performed by use of a Casy cell counter. Chondrocytes' cell death was examined by fluorescence microscopy and an XTT ELISA assay. Results Light microscope and fluorescence microscope data revealed a defect cell structure and increased number of dead cells after addition of 1% or 2% lidocaine and bupivacaine but not ropivacaine. We were able to show an increased level of XTT activity after treatment with bupivacaine, 2% lidocaine or ropivacaine. The count of vital chondrocytes was significantly decreased after treatment with bupivacaine, 1% or 2% lidocaine, and ropivacaine. Conclusions The data show that treatment with local anesthetics induces cell damage of human chondrocytes in vitro. Ropivacaine seems to be a local anesthetic with the lowest toxic potential on human chondrocytes, a feature that may favor its preference for use in joint injection.

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Locally applied vancomycin is increasingly being used in primary hip and knee arthroplasty to reduce the risk of infection. Despite encouraging initial results, considerable debate remains on the basis of the data currently available. In particular, it has been unclear up to now whether local vancomycin is suitable to further reduce the risk of infection even if the rate of infection is already low (< 1%). In this monocentric retrospective cohort study, all primary total hip and knee arthroplasties performed between 2013 and 2018 were included. After a change in procedure at the hospital, 1 g vancomycin powder was applied intraarticularly before wound closure. The remaining perioperative procedure was constant over the investigation period. The follow-up was one year. The presence of an infection according to the currently valid MSIS criteria was defined as the endpoint. In patients with TKA two infections (0.3%) were observed under vancomycin prophylaxis in contrast to 44 infections (1.3%) in the control group (p = 0.033). In patients with THA two infections (0.5%) were observed under vancomycin prophylaxis and 48 infections (1.1%) in the control group without local vancomycin but this difference was statistically not significant. No wound complications requiring revision were observed as a result of the vancomycin. On the basis of the results of this study, intraarticular application of vancomycin powder in total hip and knee arthroplasty may be considered. Prospective randomized studies have to confirm this promising results prior a common recommendation. Level of Evidence III Retrospective cohort study. Infections after endoprosthetic hip or knee replacement, in spite of all perioperative improvements, are observed with an incidence of 1-2% 1-4. Despite the apparently low risk, efforts to further reduce the risk are sensible in light of the consequences for the patients concerned, with the potential for several follow-up operations and the often limited functional outcome. In spinal surgery, the reduction in the rate of infection through locally applied vancomycin was established more than 10 years ago and has been well documented by meta-analyses and animal experiments 5-8. The positive effect is set against minor complications caused in 0.3% of cases, mostly culture-negative seroma formation 9, so that it is even used successfully in children 10. Otte et al. were able to show that intrawound vancomycin powder lowers the infection rate after knee and hip arthroplasty from 1.6 to 0.5%, compared with a control group 11. In a subgroup analysis, the effect in revision operations was even greater, with a reduction of the infection rate from 3.9 to 0%. Patel et al. showed a reduction in the infection rate through vancomycin of 2.7-0.3% and determined a number needed to treat (NNT) of 47.5 12. Systemic side effects were not observed. The local application of vancomycin was assessed to be safe and cost-effective. Dial et al. observed a similar effect in primary hip arthroplasty, with a lowering of the infection rate...

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A lethal chondrodysplasia characterized by extreme micromelia was diagnosed by ultrasound examination in two sibs whose nonconsanguineous parents were healthy. Radiographic and histopathologic data indicated that the two foetuses (18 and 21 weeks old) had achondrogenesis type IB (Fraccaro). Quantitation of total collagen extractable from dried cartilage samples demonstrated a 50% decrease when compared to an age-related control. This decrease was essentially related to type II collagen. Nevertheless, the alpha chains and the CB peptides of type II collagen had a normal electrophoretic mobility. A significant amount of collagen type I was also detected. The electrophoretic pattern of collagens type IX and XI did not differ significantly from control sample. The extracellular matrix elaborated by patient chondrocytes cultured in agarose for 10-12 days, contained less collagen type II than normal cells. Labelling with 14C-proline of cultured cells showed the presence of procollagen and type II collagen chains with a normal electrophoretic mobility, but an alpha 2(I) chain was detectable in the patient material, indicating the presence of collagen type I which supported the tissue findings. The significance of the type II collagen reduction in the patient's cartilage is unclear but it is unlikely to be the primary defect in achondrogenesis type I.

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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 efectiveness of sodium hypochlorite and chlorhexidine against bacterial bioilms. 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 luorescent 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 bioilms 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 efective than chlorhexidine in penetrating bioilms 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 indings conirm the efectiveness of sodium hypochlorite and chlorhexidine against bacterial bioilms. Both antiseptics can be recommended for the treatment of periprosthetic infections. The toxic efects of sodium hypochlorite and chlorhexidine towards chondrocytes may mean there is a risk of damage to cartilage tissue. Level of evidence Controlled experimental study.

PurposeThe optimal degree of constraint of a total knee arthroplasty for treatment of knee osteoarthritis with ligamentous laxity is under debate. While varus valgus constrained knees require a minimum level of ligamentous stability, rotating hinge knees can even be implanted if the collateral ligaments have been lost completely. It seems plausible that joint kinematics are determined by implant design in rotating hinge knees, whereas varus valgus constrained knees may be influenced by remaining stabilizers. This may result in more predictable clinical results of hinge knees. The hypothesis of the present study, therefore, was that stability and clinical outcome are better after total knee arthroplasty using rotating hinge knees than after using varus valgus constrained knees. MethodsAll patients who were treated using a mobile‐bearing varus valgus constrained knee or a rotating hinge knee for treatment of end‐stage osteoarthritis and ligamentous laxity were included. At follow‐up, clinical scores were determined (WOMAC, VAS, KSS, FJS, Lysholm). Furthermore, body mass index, operating time, and postoperative complications were documented. Whole leg radiographs as well as patella axial radiographs were analyzed for implant alignment and patella tracking. ResultsEighty‐five patients were included in this retrospective study. Both groups showed an average range of motion of 113°. No significant difference between the two groups was observed for any of the scores recorded. In the rotating hinge knee group, a more precise tibia positioning in relation to the mechanical axis but also a significant lateralisation and tilting of the patella were seen, compared with the varus valgus constrained knee group. ConclusionsRotating hinge knees did not perform better than mobile‐bearing varus valgus constrained knees clinically. Both prosthesis types showed equally good clinical outcomes with regard to stability, mobility, satisfaction, pain and operating time. Level of evidenceRetrospective case series, Level IV.