Cementing technique for total knee arthroplasty in cadavers using a pastry bone cement.

BACKGROUND: In cemented primary total knee arthroplasty (TKA), aseptic loosening remains a major cause for failure. Cementing techniques and characteristics of a chosen cement play a key role for good fixation and implant survival. A pastry bone cement was developed to facilitate the cement preparation and to rule out most of preparation-associated application errors. The pastry bone cement was compared to a conventional polymethyl methacrylate cement in a TKA setting. METHODS: Standardized implantations of total knee endoprostheses were performed in bilateral knee cadavers to investigate handling properties, variables of cement application, working time, and temperature development. Mechanical aspects and cementation quality were assessed by pull-out trials and microscopic interface analysis. RESULTS: Both cements expressed similar characteristics during preparation and application, only the curing time of the pastry cement was about 3 min longer and the temperature peak was lower. Fractures of the conventional cement specimens differed from the pastry cement specimens in the tibial part, while no differences were found in the femoral part. Penetration depth of the pastry cement was similar (tibia) or deeper (femur) compared to the conventional cement. CONCLUSIONS: The pastry cement facilitates the feasibility of cemented TKA. The pre-clinical tests indicate that the pastry bone cement fulfills the requirements for bone cement in the field of knee arthroplasty. A clinical trial is needed to further investigate the approach and ensure patient safety.

Properties and clinical application safety of antibiotic-loaded bone cement in kyphoplasty.

BACKGROUND: Evidence on antibiotic-loaded bone cement remains too vague to guide kyphoplasty in patient care. We clinically evaluated the properties and benefits of a new low viscosity polymethylmethacrylate (PMMA) bone cement loaded with gentamicin. METHODS: In this non-randomised, monocentric, prospective open trial, 50 consecutively enrolled patients with fractures of the vertebral body (TH7-L4) due to osteoporosis or trauma were investigated between 2010 and 2013, with a 1-year post-op follow-up per patient. The antibiotic-loaded PMMA bone cement was administered to patients during the surgery according to the standard procedure established on site for one-staged kyphoplasty. The clinical outcome was assessed according to function and pain by standardised anamnesis, clinical investigation, validated visual analogue scale (VAS) vertebral spine score, Oswestry Low-Back-Pain (ODI) Disability score, and Short Form (SF)-36 score. We further performed X-ray and magnetic resonance imaging with radiomorphometric assessment. RESULTS: The patients showed beneficial effects concerning low back pain disability (mean ODI score; screening, 68.0 ± 15.8% vs month 12, 42.8 ± 24.5%). The pain level was decreased (VAS vertebral spine score; screening, 68.8 ± 17.6 vs month 12, 43.8 ± 22.2) and the general health state was improved (SF-36; especially 'role limitations due to emotional problems' (51.9 ± 44.7; month 6), followed by 'role limitations due to physical health' (36.1 ± 42.4; month 6), and 'pain' (34.6 ± 35.3; month 6)). No vertebral infection did occur during the hospital stay or the 1-year follow-up. The stabilisation and restoration of the fractured bodies were radiologically confirmed. A reduced rate of leakage was observed, combined with a decreased risk of infection and an improved patient safety after a 1-year follow-up period. CONCLUSION: Requirements for bone cement in a kyphoplasty setting were excellently fulfilled. Application technique and cement properties may influence the success of the surgery. TRIAL REGISTRATION: Deutsche Institut für Medizinische Dokumentation und Information (DIMDI), HM-KS-0901, Registered 14 September 2009, https://www.dimdi.de/dynamic/de/medizinprodukte/datenbankrecherche/.

Antibiotics release from cement spacers used for two-stage treatment of implant-associated infections after total joint arthroplasty.

Two-stage revision arthroplasty is the treatment of choice for periprosthetic infection, a serious complication after knee or hip arthroplasty. Our prospective clinical trial aimed to investigate the concentrations of gentamicin and vancomycin in wound exudate and tissue in two-stage revision arthroplasty. Wound exudate and periprosthetic membrane samples were collected from 18 patients (10 hip and eight knee patients), who were due for two-stage treatment after a periprosthetic joint infection. Samples were taken during insertion of antibiotic-impregnated spacers and after their removal. The concentrations of gentamicin and vancomycin in wound exudates and adjacent tissue were analyzed using high-performance liquid chromatography mass spectrometry. Average time period of spacer implantation was 13.6 weeks (9.3-22.6 weeks). The concentration of vancomycin in wound exudate decreased from a median of 43.28 µg/mL (0.28-261.22) after implantation to 0.46 µg/mL (0.13-37.47) after the removal of the spacer. In the adjacent tissue, vancomycin concentration was mainly undetectable prior to spacer implantation (0.003 µg/g [0.003-0.261]) and increased to 0.318 µg/g [0.024-484.16] at the time of spacer removal. This was also observed for gentamicin in the tissue of patients who previously had cement-free implants (0.008 µg/g [0.008-0.087] vs. 0.164 µg/g [0.048-71.75]) while in the tissue of patients with previously cemented prosthesis, baseline concentration was already high (8.451 µg/g [0.152-42.926]). Despite the rapid decrease in antibiotics release from spacer cement observed in vitro, in vivo antibiotics are much longer detectable, especially in the adjacent soft tissue. © 2018 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published By Wiley Periodicals, Inc. J Biomed Mater Res B Part B, 2019. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1587-1597, 2019.

Long-term results of revision total hip arthroplasty with a cemented femoral component.

INTRODUCTION: In revision total hip arthroplasty (THA), the cancellous bone is normally completely removed out of the femoral canal during stem extraction. This situation is comparable to primary THA following the shape-closed concept, with some authors advocating to remove the metaphyseal cancellous bone to enhance press-fit stability ("French paradox"). The aim of this study was to investigate the long-term outcome, regarding survival and radiological results, of a cemented straight stem when used for revision THA and to compare these results to the results of the same stem in primary THA. MATERIALS AND METHODS: 178 stem revisions performed between 01/1994 and 08/2008 using the Virtec straight stem were included. The cumulative incidence for re-revision was calculated using a competing risk model. Risk factors for re-revision of the stem were analyzed using an absolute risk regression model. Radiographs analyzed for osteolysis, debonding and subsidence had a minimum follow-up of 10 years. RESULTS: The cumulative incidence for re-revision due to aseptic loosening of the stem was 5.5% (95% CI, 2.9-10.2%) at 10 years. Aseptic loosening was associated with younger age, larger defect size and larger stem size. After a minimum 10-year follow-up, osteolysis was seen in 39 of 80 revision THA. Compared to the results in primary THA, the survival in revision THA with the same implant was inferior. CONCLUSIONS: Cemented straight stems used for revision THA showed excellent long-term results regarding survivorship and radiological outcome. This stem therefore offers a valuable and cost-effective option in revision THA.

Bioavailability of gentamicin and vancomycin released from an antibiotic containing bone cement in patients undergoing a septic one-stage total hip arthroplasty (THA) revision: a monocentric open clinical trial.

BACKGROUND: The purpose of this clinical investigation was to evaluate the systemic bioavailability of antibiotics from bone cement after implantation. This was done by determining the concentrations of gentamicin and vancomycin in plasma and urine of patients receiving a novel bone cement during one-stage revision in periprosthetic hip infections. The local concentrations of both antibiotic agents in wound exudate as well as the efficacy and tolerability were assessed as a secondary objective. METHODS: In a prospective open clinical trial, 20 patients (mean age 62.5 years) with an implanted hip prosthesis requiring revision due to periprosthetic infection were treated with this antibiotic loaded bone cement (ALBC) between 2009 and 2011. The concentrations of gentamicin and vancomycin in plasma, urine and wound exudate were determined with quantitative liquid chromatography analysis (LC-MS-MS). RESULTS: The mean postoperative maximum gentamicin plasma concentration at 5.85 hours was 209.65 ng/mL. For vancomycin, a mean postoperative maximum plasma concentration of 134.64 ng/mL was determined at 20.03 hours. Small amounts of both antibiotics were excreted via the urine within the first 10 days after surgery. No reinfection was observed at the end of the hospital stay or during the follow-up period up to 7 months post surgery. CONCLUSIONS: Slow absorption of both antibiotics after release from the cement resulted in plasma concentrations well below toxic levels and did not result in a critical systemic concentration potientially inducing bacterial resistance. The treatment with this novel bone cement was assessed as efficacious and was very well tolerated by all patients.

Treatment of a chronic recurrent fistulized tibial osteomyelitis: administration of a novel antibiotic-loaded bone substitute combined with a pedicular muscle flap sealing.

Persistent osteomyelitis is a severe and challenging problem in bone surgery. We describe a surgical intervention in a young adult which combines a bone debridement process, a plastic muscle flap sealing and the administration of a novel bone substitution material with anti-infective properties. After 1 year, the patient showed no signs or symptoms of a reoccurrence of infection with full load capacity of the treated leg.