Role of fast-setting cements in arthroplasty: A comparative analysis of characteristics

AIM To evaluate the behaviour of two fast-setting polymethylmethacrylate(PMMA) cements CMW~? 2 G and Palacos~? fast R + G, as reference: Standard-setting Palacos~? R + G.METHODS The fast-setting cements CMW~? 2 G and Palacos~? fast R + G were studied, using standard-setting high viscosity Palacos~? R + G as a reference. Eleven units(of two batch numbers) of each cement were tested. All cements were mixed as specified by the manufacturer and analysed on the following parameters: Handling properties(mixing, waiting, working and hardening phase) according to Kuehn, Mechanical properties according to ISO 5833 and DIN 53435, Fatigue strength according to ISO 16402, Benzoyl Peroxide(BPO)-Content by titration, powder/liquid-ratio by weighing, antibiotic elution profile by High Performance Liquid Chromatography. All tests were done in an acclimatised laboratory with temperatures set at 23.5 ℃± 0.5 ℃ and a humidity of > 40%. RESULTS Palacos~? fast R + G showed slightly shorter handling properties(doughing, hardening phase, n = 12) than CMW~? 2 G, allowing to reduce operative time and to optimise cemented cup implantation. Data of the quasistatic properties of ISO 5833 and DIN 53435 of both cements tested was comparable. The ISO compressive strength(MPa) of Palacos~? fast R + G was significantly higher than CMW~? 2 G, resulting in ANOVA(P < 0.01) and two sample t-test(P < 0.01) at 0.05 level of significance(n = 20). Palacos~? fast R + G showed a higher fatigue strength of about 18% mean(ISO 16402) of 15.3 MPa instead of 13.0 MPa for CMW~? 2 G(n = 5 × 10~6 cycles). Palacos~? fast R + G and CMW~? 2 G differed only by 0.11%(n = 6) with the former having the higher content. The BPO-content of both cements were therefore comparable. CMW~? 2 G had a powder/liquid ratio of 2:1, Palacos~? fast R + G of 2.550:1 due to a higher powder content. Despite its higher gentamicin content, CMW~? 2 G showed a significantly lower antibiotic elution over time than Palacos~? fast R + G(n = 3). CONCLUSION Both cements are compliant with international standards and are highly suitable for their specified surgical indications, affording a time-saving measure without detriment to the mechanical properties.

Salmonella infection after anterior cruciate ligament reconstruction:A case report

BACKGROUND Infections after anterior cruciate ligament reconstruction(ACLR)are rare.No cases of Salmonella infection have been described to our knowledge.CASE SUMMARY We describe a rare case of Salmonella infection in a 23-year-old patient following an ACLR.The patient presented with subacute septic arthritis,26 d after a hamstring autograft ACLR.The pathogen,Salmonella enterica typhimurium was isolated by bacteriological sampling of the first arthroscopic lavage.Two arthroscopic lavages were required,with intravenous antibiotic therapy for two weeks with cefotaxime and ciprofloxacin,followed by oral antibiotics with amoxicillin and ciprofloxacin for a total duration of three months.This approach treated the infection but two years after the septic arthritis,faced with ongoing knee instability due to graft damage,a revision ACLR with a bone-tendon-bone graft was performed.At the last follow-up,full range of knee motion had been achieved and sports activities resumed.CONCLUSION Infection after ACLR is rare and requires an early diagnosis and management in order to treat the infection and prevent arthritis-related joint cartilage destruction and damage to the graft.