Impact of Positive Cultures During the Second Stage of a Two-Stage Exchange: Systematic Review and Meta-Analysis.

BACKGROUND: Two-stage exchange is a frequently performed procedure in patients who have a periprosthetic joint infection. Positive cultures when performing the second stage are perceived as a risk factor for reinfection. This study aimed to determine the impact of positive cultures during the second stage on the outcome of patients undergoing a 2-stage septic exchange and the impact of stopping the antibiotic treatment before reimplantation. METHODS: We systematically searched four databases. We performed a meta-analysis on the risk of complications after positive cultures during second stage and a subgroup analysis by antibiotic holiday period. We included 24 studies. RESULTS: Failure in the positive group was 37.0% and in the negative group was 13.7% with an odds ratio (OR) of 4.05. In the subgroup analysis by antibiotic holidays, failure rate without holidays was 15% and with holidays was 17.3% (P = .21). Failure in each group was higher when cultures were positive (without holidays, 25 versus 12.2%, P = .0003, and with holidays 41.1 versus 12.7%, P < .0001), but the risk of failure when cultures were positive was higher in the holiday group (OR 4.798) than in the nonholiday group (OR 2.225) in comparison to those patients who were culture negative at the second stage. CONCLUSIONS: Microbiological eradication at second stage was not obtained in 18% of cases and it was associated with a higher failure rate. In patients with positive cultures, withholding antibiotic treatment was associated with lower failure rate. Further studies to define the antibiotic strategy in 2-stage exchange procedure are necessary.

Identifying Critical Evidence Gaps in Wound Closure and Incision Management After Total Knee Arthroplasty: Delphi Panel Insights.

BACKGROUND: Effective surgical wound management in total knee arthroplasty (TKA) is crucial for optimal healing and patient outcomes. Despite surgical advances, managing wounds to prevent complications remains challenging. This study aimed to identify and address evidence gaps in TKA wound management, including preoperative optimization, intraoperative options, and postoperative complication avoidance. Addressing these issues is vital for patient recovery and surgical success. METHODS: This study used the Delphi method with 20 experienced orthopedic surgeons from Europe and North America. Conducted from April to September 2023, the process involved three stages: an initial electronic survey, a virtual meeting, and a concluding electronic survey. The panel reviewed and reached a consensus on 26 statements about TKA wound management based on a comprehensive literature review. Additionally, the panel aimed to identify critical evidence gaps in wound management practices. RESULTS: The panel achieved consensus on various wound management practices but highlighted significant evidence gaps. Consensus was reached on wound closure methods, including mesh-adhesive dressings, skin glue, staples, barbed sutures, and negative pressure wound therapy. However, further evidence is needed to address the cost-effectiveness of these methods and develop best practices for patient outcomes. Identifying these gaps highlights the need for more research to improve TKA wound care. CONCLUSIONS: Identifying major evidence gaps underscores the need for targeted research in TKA wound management. Addressing these gaps is crucial for developing effective, efficient, and patient-friendly wound care strategies. Future research should focus on comparative effectiveness studies and developing guidelines for emerging technologies. Bridging these gaps could improve patient outcomes, reduce complications, and enhance TKA surgery success.

International Delphi Study on Wound Closure and Incision Management in Joint Arthroplasty Part 2: Total Hip Arthroplasty.

BACKGROUND: This modified Delphi study aimed to develop a consensus on optimal wound closure and incision management strategies for total hip arthroplasty (THA). Given the critical nature of wound care and incision management in influencing patient outcomes, this study sought to synthesize evidence-based best practices for wound care in THA procedures. METHODS: An international panel of 20 orthopedic surgeons from Europe, Canada, and the United States evaluated a targeted literature review of 18 statements (14 specific to THA and 4 related to both THA and total knee arthroplasty). There were 3 rounds of anonymous voting per topic using a modified 5-point Likert scale with a predetermined consensus threshold of ≥ 75% agreement necessary for a statement to be accepted. RESULTS: After 3 rounds of voting, consensus was achieved for all 18 statements. Notable recommendations for THA wound management included (1) the use of barbed sutures over non-barbed sutures (shorter closing times and overall cost savings); (2) the use of subcuticular sutures over skin staples (lower risk of superficial infections and higher patient preferences, but longer closing times); (3) the use of mesh-adhesives over silver-impregnated dressings (lower rate of wound complications); (4) for at-risk patients, the use of negative pressure wound therapy over other dressings (lower wound complications and reoperations, as well as fewer dressing changes); and (5) the use of triclosan-coated sutures (lower risk of surgical site infection) over standard sutures. CONCLUSIONS: Through a structured modified Delphi approach, a panel of 20 orthopedic surgeons reached consensus on all 18 statements pertaining to wound closure and incision management in THA. This study provides a foundational framework for establishing evidence-based best practices, aiming to reduce variability in patient outcomes and to enhance the overall quality of care in THA procedures.

International Delphi Study on Wound Closure and Dressing Management in Joint Arthroplasty: Part 1: Total Knee Arthroplasty.

BACKGROUND: The purpose of this modified Delphi study was to obtain consensus on wound closure and dressing management in total knee arthroplasty (TKA). METHODS: The Delphi panel included 20 orthopaedic surgeons from Europe and North America. There were 26 statements identified using a targeted literature review. Consensus was developed for the statements with up to three rounds of anonymous voting per topic. Panelists ranked their agreement with each statement on a five-point Likert scale. An a priori threshold of ≥ 75% was required for consensus. RESULTS: All 26 statements achieved consensus after three rounds of anonymous voting. Wound closure-related interventions that were recommended for use in TKA included: 1) closing in semi-flexion versus extension (superior range of motion); 2) using aspirin for venous thromboembolism prophylaxis over other agents (reduces wound complications); 3) barbed sutures over non-barbed sutures (lower wound complications, better cosmetic appearances, shorter closing times, and overall cost savings); 4) mesh-adhesives over other skin closure methods (lower wound complications, higher patient satisfaction scores, lower rates of readmission); 5) silver-impregnated dressings over standard dressings (lower wound complications, decreased infections, fewer dressing changes); 6) in high-risk patients, negative pressure wound therapy over other dressings (lower wound complications, decreased reoperations, fewer dressing changes); and 7) using triclosan-coated over non-antimicrobial-coated sutures (lower risks of surgical site infection). CONCLUSIONS: Using a modified Delphi approach, the panel achieved consensus on 26 statements pertaining to wound closure and dressing management in TKA. This study forms the basis for identifying critical evidence supported by clinical practice for wound management to help reduce variability, advance standardization, and ultimately improve outcomes during TKA. The results presented here can serve as the foundation for knowledge, education, and improved clinical outcomes for surgeons performing TKAs.

The tale of microencapsulated rifampicin: is it useful for the treatment of periprosthetic joint infection?

PURPOSE: Microencapsulation techniques have allowed the addition of rifampicin to bone cement, but its in vivo efficacy has not been proven. The aim of our study is to determine the superiority of cement containing gentamicin and rifampicin microcapsules in the treatment of PJI versus cement exclusively containing gentamicin. METHODS: An S. aureus PJI was induced in 15 NZW rabbits. A week after inoculation, the first stage of replacement was carried out, and the animals were divided into two groups: group R received a spacer containing gentamicin and rifampicin microcapsules, and group C received a spacer containing gentamicin. Intra-articular release curve of rifampicin and infection and toxicity markers were monitored for four weeks post-operatively, when microbiological analysis was performed. RESULTS: The microbiological cultures showed a significantly lower growth of S. aureus in soft tissue (2.3·104 vs 0; p = 0.01) and bone (5.7·102 vs 0; p = 0.03) in the group with rifampicin microcapsules. No differences were found in systemic toxicity markers. Rifampicin release from the cement spacer showed higher concentrations than the staphylococcal MIC throughout the analysis. CONCLUSION: The in vivo analyses demonstrated the superiority of cement containing gentamicin and rifampicin microcapsules versus the isolated use of gentamicin in the treatment of PJI in the rabbit model without serious side effects due to the systemic absorption of rifampicin. Given the increasing incidence of staphylococci-related PJI, the development of new strategies for intra-articular administration of rifampicin for its treatment has a high clinical impact.

Conceptual evolution of 3D printing in orthopedic surgery and traumatology: from "do it yourself" to "point of care manufacturing".

BACKGROUND: 3D printing technology in hospitals facilitates production models such as point-of-care manufacturing. Orthopedic Surgery and Traumatology is the specialty that can most benefit from the advantages of these tools. The purpose of this study is to present the results of the integration of 3D printing technology in a Department of Orthopedic Surgery and Traumatology and to identify the productive model of the point-of-care manufacturing as a paradigm of personalized medicine. METHODS: Observational, descriptive, retrospective and monocentric study of a total of 623 additive manufacturing processes carried out in a Department of Orthopedic Surgery and Traumatology from November 2015 to March 2020. Variables such as product type, utility, time or materials for manufacture were analyzed. RESULTS: The areas of expertise that have performed more processes are Traumatology, Reconstructive and Orthopedic Oncology. Pre-operative planning is their primary use. Working and 3D printing hours, as well as the amount of 3D printing material used, vary according to the type of product or material delivered to perform the process. The most commonly used 3D printing material for manufacturing is polylactic acid, although biocompatible resin has been used to produce surgical guides. In addition, the hospital has worked on the co-design of customized implants with manufacturing companies. CONCLUSIONS: The integration of 3D printing in a Department of Orthopedic Surgery and Traumatology allows identifying the conceptual evolution from "Do-It-Yourself" to "POC manufacturing".

Is Dual Antibiotic-Loaded Bone Cement More Effective and Cost-Efficient Than a Single Antibiotic-Loaded Bone Cement to Reduce the Risk of Prosthetic Joint Infection in Aseptic Revision Knee Arthroplasty?

BACKGROUND: Higher rates of prosthetic joint infections (PJIs) are related to patient risk factors and/or to special surgical procedures such as revision total knee arthroplasty (rTKA). Among the measures discussed to better protect those patients from the higher infection risks use of dual antibiotic-loaded bone cement has emerged as a further prophylactic option. METHODS: This retrospective study included 246 patients undergoing strictly aseptic revision knee arthroplasty at our institution in the time period 2015-2018. Based on the type of bone cement used for the cementation of the revision prosthesis, 2 groups were defined. In total, 143 patients received the low-dose single antibiotic-loaded bone cement (SALBC) PALACOS R+G and 103 patients received the high-dose dual antibiotic-loaded bone cement (DALBC) COPAL G+C. The number of PJI cases in each group over a follow-up time of minimum 1 year was compared and the extra costs for the DALBC use calculated against the economic savings per each avoided PJI case on basis of 3 different assumptions (treatment costs and amount of cement use). RESULTS: Use of DALBC in aseptic rTKA was associated with a significant reduction in PJI cases (relative risk = 57%, PJI rate in the SALBC group 4.1% vs 0% in the DALBC group, P = 0.035). The calculated total savings per patient was $1367. Depending on the economic assumptions the range of savings was between $1413 (less favorable calculation model) and $3661 (most favorable calculation model). CONCLUSION: The use of DALBC in rTKA has been found to be more effective in preventing PJI and proved cost-efficient in all our cost-calculation models.

Ultrasound-Guided Release of the Tibial Nerve and Its Distal Branches: A Cadaveric Study.

OBJECTIVES: The purpose of the study was to determine whether ultrasound (US)-guided surgery is a viable type of surgery for performing an effective release/decompression of the constricting structures that are responsible for focal nerve compression in tarsal tunnel syndrome. METHODS: Ultrasound guidance was used on cadaveric specimens to delineate the anatomic course of the nerves and vessels in the medial ankle that comprise the structures involved in tarsal tunnel syndrome. Ultrasound guidance was used on cadaveric specimens and assisted in delineating a safe surgical zone to adequately and effectively release these constrictive structures of the proximal and distal tarsal tunnels. The US-guided tarsal tunnel release/decompression was performed through 2 small 1- to 2-mm portals. After US-guided release, anatomic dissection was used to check the efficacy (release of the flexor retinaculum and deep abductor hallucis muscle) and safety (absence of neurovascular or tendon injury) of the procedure. RESULTS: In 12 fresh cadaveric specimens, US-guided release of the tibial nerve (proximal tarsal tunnel) and its branches (distal tarsal tunnel) at the medial ankle was effective in all 12 specimens (100% release rate), without any signs of compromise or injury into the neurovascular structures. CONCLUSIONS: Ultrasound-guided tarsal tunnel release is a feasible surgical procedure that can be safe and effective with the proper training, although further investigation is warranted. This type of surgery may promote faster recovery with less postoperative morbidity, including pain, but this will be the subject of a further investigation.

Proximal Ultrasound-Guided Gastrocnemius Recession: A New Ultra-Minimally Invasive Surgical Technique.

Selective proximal recession of the medial gastrocnemius head has clear advantages over other approaches and can be performed as a single or combined open procedure for many indications. The purpose of this study was to evaluate the safety and efficacy of a new technique based on ultrasound-guided ultraminimally invasive proximal gastrocnemius recession. We performed a pilot study with 16 cadavers to ensure that the technique was effective and safe; we then prospectively performed gastrocnemius recession in 12 patients (23 cases) with gastrocnemius contracture associated with other indications. We evaluated pre- and postprocedure dorsiflexion, clinical outcomes (based on the visual analog scale and American Orthopedic Foot and Ankle Society scores), and potential complications. We achieved effective release of the proximal medial gastrocnemius tendon in all cases, with no damage to other tissue. Ankle dorsiflexion increased 12° (range 6° to 18°) (p = .05) and was maintained throughout follow-up. The mean preoperative visual analog scale score was 7 (range 5 to 9), which improved to 1 (range 0 to 2) (p = .01). The American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score improved from a mean of 25 (range 20 to 40) to 85 (range 80 to 100) at 6 months and 90 at 12 months (p = .01). No major complications were observed. We considered the technique to be safe and effective for ultrasound-guided ultraminimally invasive proximal-medial gastrocnemius recession using a 1-mm incision in vivo. This novel technique is an alternative to open techniques, with encouraging results and with the potential advantages of reducing pain and obviating lower limb ischemia and deep anesthesia, thus decreasing complications and contraindications and accelerating recovery, although further studies are required.

3D printing in experimental orthopaedic surgery: do it yourself.

INTRODUCTION: Periprosthetic infection is considered an increasing incidence pathology whose therapeutic strategies can be defined as unsatisfactory. Currently, animal models are employed to study its physiopathology and strategic therapies, but non-species-specific materials are implanted as foreign bodies. The use of these implants implies intrinsic instability, which hinders the development of a biofilm on their surfaces and complicates the post-operative recovery of the animal. The objective of the present study is the design of a species-specific implant for the New Zealand white (NZW) rabbit by means of 3D printing. MATERIALS AND METHODS: A CT scan of the knee of a NZW rabbit was performed, and the tibial surface was reconstructed in order to fabricate a species-specific tibial plateau using Horos® and Autodesk® Meshmixer™ software. This implant was inserted in fifteen NZW rabbits, and the assessment of its stability was based on the position of the limb at rest and the animal weight-bearing capacity. Biofilm formation on the surface was demonstrated by crystal violet staining. RESULTS: A 1.81 cm × 1 cm × 1.24 cm stainless steel implant was designed. It consisted of a 4-mm-thick tibial plate with a rough surface and an eccentric metaphyseal anchoring. All of the animals exhibited hyperflexion of the operated limb immediately post-operative, and 100% could apply full weight bearing from day 5 after surgery. CONCLUSIONS: The species-specific design of implants in experimental surgery encourages rapid recovery of the animal and the development of a biofilm on their surfaces, making them ideal for the study of the physiopathology and for establishing possible therapeutic targets for prosthetic infection.

Clinical and radiological outcomes of trabecular metal systems and antiprotrusion cages in acetabular revision surgery with severe defects: a comparative study.

INTRODUCTION: Acetabular revision surgery poses a challenge due to the increased frequency of severe defects and poor quality of the remaining bone. We compare the clinical and radiological outcomes, complications, and survival of two systems commonly used in complex acetabular revisions (AAOS types II, III, and IV): trabecular metal system (TM) and Burch-Schneider antiprotrusion cages (BS). METHODS: Eighty-four patients underwent acetabular revision surgery with TM or BS in our centre between 2008 and 2014. Comparison was made of demographic and clinical characteristics, satisfaction, radiographic parameters, complications, and survival of the implants. A BS was implanted in 30.9% of the patients, while 69.1% received a TM implant. The mean follow-up was 4.77 years. RESULTS: The BS group required a significantly greater number of constrained implants (p = 0.001) and more walking aids (p = 0.04). The mean satisfaction (p = 0.02) and HHS scores at the end of the follow-up were higher in the TM group (p = 0.003). No differences were observed in the incidence of complications, though the only two cases of implant rupture corresponded to the BS group. The overall survival rate was 88.1% after 7.5 years. CONCLUSION: TM implants afforded better clinical outcomes and greater patient satisfaction than antiprotrusion cages in the treatment of severe acetabular defects.

Intraoperative radiotherapy for extremity soft-tissue sarcomas: can long-term local control be achieved?

BACKGROUND: Intraoperative electron-beam radiation therapy (IOERT) during limb-sparing surgery has the advantage of delivering a single high boost dose to sarcoma residues and surgical bed area near to radiosensitive structures with limited toxicity. Retrospective studies have suggested that IOERT may improve local control compared to standard radiotherapy and we aimed to demonstrate this theory. Therefore, we performed an observational prospective study to determine (1) if it is possible to achieve high local control by adding IOERT to external-beam radiation therapy (EBRT) in extremity soft-tissue sarcomas (STS), (2) if it is possible to improve long-term survival rates, and (3) if toxicity could be reduced with IOERT MATERIALS AND METHODS: From 1995-2003, 39 patients with extremity STS were treated with IOERT and postoperative radiotherapy. The median follow-up time was 13.2 years (0.7-19). Complications, locoregional control and survival rates were collected. RESULTS: Actuarial local control was attained in 32 of 39 patients (82%). Control was achieved in 88% of patients with primary disease and in 50% of those with recurrent tumors (p = 0.01). Local control was shown in 93% of patients with negative margins and in 50% of those with positive margins (p = 0.002). Limb-sparing was achieved in 32 patients (82%). The overall survival rate was 64%. 13% of patients had grade ≥3 acute toxicity, and 12% developed grade ≥3 chronic toxicity. CONCLUSION: IOERT used as a boost to EBRT provides high local control and limb-sparing rates in patients with STS of the extremities, with less toxicity than EBRT alone.

Is the Commercial Antibiotic-Loaded Bone Cement Useful in Prophylaxis and Cost Saving After Knee and Hip Joint Arthroplasty? The Transatlantic Paradox.

BACKGROUND: The use of antibiotic-loaded bone cement (ALBC) has proven to be effective in preventing periprosthetic infection (PPI) after total hip (THA) and knee arthroplasty (TKA). However, the economic benefit of using ALBC routinely remains controversial. METHODS: A total of 2518 patients subjected to THA, partial hip arthroplasty, and TKA between 2009 and 2012 were identified in our prospectively collected registry. Two groups were defined: before (2009-2010) and after the introduction of ALBC (2011-2012). The risks of PPI associated with each type of surgery in each group were determined and compared. Patients subjected to THA without cemented implants were used as controls, and possible bias associated with changes in infection rate during the study period and other variables were controlled. The costs of the use of ALBC were calculated, along with the savings per case of PPI avoided. The minimum follow-up for discarding PPI was 2 years. RESULTS: Following the introduction of ALBC, a global decrease of 57% was observed in the risk of PPI (P = .001). By type of surgery, the decrease was 60.6% in the case of TKA (P = .019) and 72.6% in the case of cemented hip arthroplasty (partial and total; P = .009). No decrease in infection rate was noted in uncemented hip arthroplasty (P = .42). The total saving associated with the use of ALBC was €1,123,846 (€992 per patient): €440,412 after TKA (€801 per patient) and €686,644 after cemented hip arthroplasty (€2672 per patient). CONCLUSION: The use of ALBC has been found to be effective in preventing PPI after TKA and hip arthroplasty, with a favorable cost-efficiency profile using standardized cost and infection rates in our setting.

Ultra-Minimally Invasive Ultrasound-Guided Carpal Tunnel Release: A Randomized Clinical Trial.

OBJECTIVES: The purpose of this study was to compare the outcomes of 1-mm ultra-minimally invasive ultrasound-guided carpal tunnel release and 2-cm blind mini-open carpal tunnel release. METHODS: We conducted a single-center individual parallel-group controlled-superiority randomized control trial in an ambulatory office-based setting at a third-level referral hospital. Eligible participants had clinical signs of primary carpal tunnel syndrome and positive electrodiagnostic test results and were followed for 12 months. Independent outcome assessors were blinded. Patients were randomized by concealed allocation (1:1) by an independent blocked computer-generated list. The postoperative score on the Quick-Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire was the primary variable. Grip strength and time for discontinuation of oral analgesics, complete wrist flexion-extension, relief of paresthesia, and return to normal daily activities (including work) were assessed. RESULTS: Ninety-two of 128 eligible patients were randomly allocated and analyzed. QuickDASH scores were 2.2 to 3.3 times significantly lower in the ultra-minimally invasive group for the first 6 months: 23.6 [95% confidence interval (CI), 20.5, 27.4] versus 52.6 [95% CI, 49.4, 57.0] at the first week and 4.09 [95% CI, 1.5, 7.1] versus 13.0 [95% CI, 9.4, 18.9] at 6 months. Return to normal daily activities occurred significantly sooner in the ultra-minimally invasive group: 4.9 [95% CI, 3.2, 6.5] versus 25.4 [95% CI, 18.2, 32.6] days. CONCLUSIONS: Ultra-minimally invasive carpal tunnel release provides earlier functional return and less postoperative morbidity with the same neurologic recovery as mini-open carpal tunnel release for patients with symptomatic primary carpal tunnel syndrome.

Ultrasound-guided gastrocnemius recession: a new ultra-minimally invasive surgical technique.

BACKGROUND: Isolated gastrocnemius contracture is thought to lead to numerous conditions. Although many techniques have been described for gastrocnemius recession, potential anesthetic, cosmetic, and wound-related complications can lead to patient dissatisfaction. Open and endoscopic recession techniques require epidural anesthesia, lower limb ischemia, and stitches and may lead to damage of the sural nerve, which is not under the complete control of the surgeon at all stages of the procedure. The purpose of this study was to evaluate the safety and efficacy of a new technique based on ultrasound-guided ultra-minimally invasive gastrocnemius recession. METHODS: We performed a pilot study with 22 cadavers to ensure that the technique was effective and safe. In the second phase, we prospectively performed gastrocnemius recession in 23 patients (25 cases) with chronic non-insertional Achilles tendinopathy, equinus foot, and other indications. In the clinical study, we evaluated the range of dorsiflexion before and after the procedure, clinical outcomes with VAS and AOFAS scores, and potential complications, including neurovascular injuries. RESULTS: We achieved complete release of the gastrocnemius tendon in all cases in the cadaveric study, with no damage to the sural nerve or vessels and minimal damage to the underlying muscle fibers. Ankle dorsiflexion increased for every patient in the study (mean, 14°; standard deviation, 3°) and was maintained throughout follow-up. The mean preoperative VAS score was 7 (6-9), which improved to 0 (0-1). The AOFAS Ankle-Hindfoot Score improved from a mean of 30 (20-40) to 93 (85-100) at 6 months. No major complications were observed. All patients returned to their previous sports after 6 months. CONCLUSIONS: After cadaveric and clinical study, we considered the technique to be safe and effective to perform ultrasound-guided ultra-minimally invasive gastrocnemius recession using a 1-mm incision in vivo. This novel technique represents an alternative to open techniques, with encouraging results and with the advantages of reducing pain, obviating lower limb ischemia, deeper anaesthesia, thus decreasing complications and contraindications and accelerating recovery.

Revision TKA with a condylar constrained prosthesis using metaphyseal and surface cementation: a minimum 6-year follow-up analysis.

BACKGROUND: The increasing number of revision knee arthroplasty result in the more frequently use of a constraint implant but results from previous reports are difficult to interpret. The purpose of this study was to compare the long-term outcomes of superficial cemented versus metaphyseal cemented in revision total knee arthroplasty with a condylar constrained arthroplasty. METHODS: The study was a retrospective analysis of clinical and radiographic outcomes in a series of revision total knee arthroplasties performed with a constrained condylar knee prosthesis and press-fit modular stems. We hypothesized that the clinical and radiographic outcome of surface cementation would be inferior to that of metaphyseal cementation. Fifty-two consecutive revision cases were followed for a median of 8.2 years (range, 6 to 10 years). RESULTS: Substantial improvements in range of motion and Knee Society score were achieved in all patients, although these were not significant between groups. Significantly more radiolucent lines were visible on the tibial component with surface cementation than with metaphyseal cementation, although the clinical differences were not relevant. CONCLUSIONS: Radiologic outcome was better in revision total knee arthroplasty using metaphyseal cemented revision and components with press-fit cementless stems than in the surface cementation-based approach; however, the difference was not clinically relevant.

Evaluation of Elution and Mechanical Properties of High-Dose Antibiotic-Loaded Bone Cement: Comparative "In Vitro" Study of the Influence of Vancomycin and Cefazolin.

Use of antibiotic-loaded bone cements is one of the most effective methods for the prevention and treatment of prosthetic joint infection. However, there is still controversy about the optimal combination and doses of antibiotics that provide the maximum antimicrobial effect without compromising cement properties. In this study, vancomycin and cefazolin were added to a bone cement (Palacos R+G). Antibiotic release, fluid absorption, and mechanical properties were evaluated under physiological conditions. The results show that the type of antibiotic selected has an important impact on cement properties. In this study, groups with cefazolin showed much higher elution than those containing the same concentration of vancomycin. In contrast, groups with cefazolin showed a lower strength than vancomycin groups.

Effects of vancomycin, cefazolin and test conditions on the wear behavior of bone cement.

Antibiotic cement has been recommended in the treatment of prosthetic infections. The purpose of this study was to investigate the mechanical behavioral changes in cement loaded with two antibiotics, vancomycin and cefazolin, in dry and liquid medium. Six groups and four study conditions were established according to the doses of antibiotic used and the ageing (immersion in phosphate buffered saline) of the samples. Properties evaluated were friction coefficient and wear. Samples in dry medium showed higher wears than in liquid. Antibiotic selection did not influence wear properties tested in dry conditions, however, in liquid medium, there were higher frictional coefficients and wear for cefazolin loaded cement after one week and for vancomycin and cefazolin after one month. The results suggest that antibiotic cements behave differently in liquid and that the molecular characteristics of antibiotics are essential for determining this influence.