Contemporary outcomes of debridement, antibiotics and implant retention in knee arthroplasty

Periprosthetic joint infection (PJI) is a major complication after knee arthroplasty, with approximately a quarter of knee arthroplasty revisions citing PJI as an indication. With the demand for knee arthroplasty predicted to increase, coupled with a lack of evidence for decreasing PJI risk, an appreciation of the burdens of PJI on both patients and health care systems is vital. Patients with PJI can experience a reduced quality of life as well as increased morbidity, whilst the management of PJI has significant economic implications. Surgical options include debridement, antibiotics and implant retention (DAIR), single-stage revision, two-stage revision and salvage procedures. DAIR involves the systematic debridement of all infected and unhealthy tissues coupled with directed antibiotic therapy, with definitive infection clearance the objective. In contrast to single- and two-stage revision procedures for PJI, DAIR does not involve the removal of fixed implants, with only modular components exchanged. Potential benefits of DAIR include reduced tissue destruction, reduced morbidity and reduced healthcare burdens, but with a higher reinfection risk compared to staged revision techniques, and utility largely restricted to acute bacterial PJI. A review of contemporary DAIR outcomes is of value given advances in the understanding of PJI biology; the development of consensus-based definitions for PJI diagnosis and treatment outcomes; and evolution of DAIR indications and technique. This review discusses outcomes of DAIR for knee PJI, published over the last two decades

Prosthetic joint infection in the hip and knee

Prosthetic joint infection (PJI) is one of the worst complications of joint arthroplasty with an incidence of around 1% following primary arthroplasty, 3% following aseptic revision, and 20% following septic revision. It can occur following direct inoculation, haematogenous or contiguous spread. The majority of PJIs are secondary to bacterial infection although fungal PJI may be seen in multiply operated or immune compromised patients. Risk factors for PJI include patient, pathology and procedure-related factors which, where possible, should be optimized prior to surgery. The diagnosis of PJI remains a challenge and is based on patient history, clinical examination, laboratory tests, and imaging studies. No diagnostic assessment is 100% accurate with various diagnostic criteria used clinically. Investigation and treatment of PJI should be guided by a multi-disciplinary team. Surgical treatment remains the gold standard with the aim of eradicating infection. During surgery the causative organism is sought through a rigorous standardized tissue sampling technique. Surgical approaches including debridement, antibiotics and implant retention (DAIR), single-stage revision, two-stage revision, excision arthroplasty, arthrodesis and amputation. The approach used is tailored to the individual patient with the optimum surgical strategy being one that successfully eradicates the infection, but at the same time minimizes morbidity to the patient

Which global rating scale?: A comparison of the ASSET, BAKSSS, and IGARS for the assessment of simulated arthroscopic skills

Background: With the move to competency-based models of surgical training, a number of assessment methods have been developed. Of these, global rating scales have emerged as popular tools, and several are specific to the assessment of arthroscopic skills. Our aim was to determine which one of a group of commonly used global rating scales demonstrated superiority in the assessment of simulated arthroscopic skills. Methods: Sixty-three individuals of varying surgical experience performed a number of arthroscopic tasks on a virtual reality simulator (VirtaMed ArthroS). Performance was blindly assessed by two observers using three commonly used global rating scales used to assess simulated skills. Performance was also assessed by validated objective motion analysis. Results: All of the global rating scales demonstrated construct validity, with significant differences between each skill level and each arthroscopic task (p < 0.002, Mann-Whitney U test). Interrater reliability was excellent for each global rating scale. Correlations of global rating scale ratings with motion analysis were high and strong for each global rating scale when correlated with time taken (Spearman rho, 20.95 to 20.76; p < 0.001), and correlation with total path length was significant and moderately strong (Spearman rho, 20.94 to 20.64; p < 0.001). Conclusions: No single global rating scale demonstrated superiority as an assessment tool. Clinical Relevance: For these commonly used arthroscopic global rating scales, none was particularly superior and any one score could therefore be used. Agreement on using a single score seems sensible, and it would seem unnecessary to develop further scales with the same domains for these purposes

Enhanced recovery programmes in knee arthroplasty: current concepts

The concept of a multimodal approach to improve the care of surgical patients was first proposed by Kehlet in the 1990s. Measures to optimise the surgical patient, and minimise perioperative stresses, aimed to improve postoperative outcomes. Although originally introduced in colorectal surgery, these ‘enhanced recovery programmes’ have now seen widespread uptake in multiple surgical specialities, including orthopaedics. Patients undergoing knee arthroplasty are well suited to an enhanced recovery approach. These programmes optimise the patient at each stage of the surgical journey, including preoperative optimisation of fitness, perioperative anaesthetic and surgical techniques and finally postoperative rehabilitation and discharge plans. The available evidence supports a number of improvements after programme introduction, including shorter length of stay, morbidity and economics. However, the impact on other outcomes is less clear. One of the issues in the field is a lack of consensus on what interventions an enhanced recovery programme should contain and the specifics of these interventions. As a result, individual units develop their own programmes, making the interpretation and comparison of their impact difficult. This article discusses interventions that could be considered for inclusion in an enhanced recovery programme for knee arthroplasty

Objectively assessing intraoperative arthroscopic skills performance and the transfer of simulation training in knee arthroscopy: a randomised controlled trial

Purpose: Objectively investigate the transfer validity of simulation training, using wireless elbow-worn motion sensors intra-operatively to assess whether surgical simulation leads to improvements in intra-operative arthroscopic performance. Methods: Randomised controlled trial. PGY2-3 trainees in nationally-approved orthopaedic surgery posts were randomised to standard junior residency training (control group), or standard training plus additional weekly simulation training (intervention group). Both groups performed a supervised real-life diagnostic knee arthroscopy in the operating room at 13 weeks. Performance was measured using wireless elbow-worn motion sensors recording objective surgical performance metrics: the number of hand movements; smoothness; and time taken. A participant:supervisor performance ratio was used to adjust for variation in case-mix and difficulty. The study took place in a surgical simulation suite and orthopaedic operating rooms of a university teaching hospital. Results: The intervention group objectively outperformed the control group for all outcome metrics. Procedures performed by the intervention group required fewer hand movements (counts; 544[465-593] vs 893[747-1242], p<0.001), had smoother movements (ms-3; 25,842[20,867-27,468] vs 36,846[29,840-53,949], p<0.001) and took less time (seconds; 320[294-392] vs 573[477-860], p<0.001) than the control group. The cases were comparable between the groups. Standardised to the supervisors performance, the intervention group required fewer hand movements (1.9[1.5-2.1] vs 3.3[2.2-4.8], p=0.0091), less time (1.2[1.1-1.7] vs 2.6[1.6-3.0], p=0.0037) and were smoother (2.1[1.8-2.8] vs 4.3[2.8-5.4], p=0.0037) than the control group, but they didn’t perform as well as their supervisors

Operating room traffic increases aerosolized particles and compromises the air quality: A simulated study.

Background Strategies to prevent bacterial fallout and reduce particle count in the operating room (OR) are key components of preventing periprosthetic joint infection. Although OR traffic control is an important factor, a quantitative study has not been performed to investigate the influence of personnel and door opening on OR air quality. This simulated study aimed to examine the influence of these 2 factors on particle density in OR with and without the laminar air flow (LAF). Methods Both experiments took place within an empty OR of an arthroplasty unit equipped with an LAF system. First, the number of particles in the air was counted using a particle counting apparatus while 9 persons entered the room, one every 15 minutes. Second, the door was opened and closed starting with zero door openings per minute and increasing to 4 in 15-minute increments. Both experiments were performed once with the LAF turned on and once without. Results The number of personnel in the OR and the number of door openings per minute correlate with the density of particles. Both relationships were significantly reduced by turning the LAF on (correlation coefficients <0.4). With the LAF being turned on, the particle density per person decreased from 211.19 to 18.19 particles/ft3 (P < .001) and the particle density per rate of door openings declined from 117.80 to 1.90 particles/ft3 (P ¼ .017). Conclusion This study confirms that personnel and door opening are a major source of particles in the OR air. Controlling traffic is critical for reduction of particles and is likely to be a key preventative strategy in reducing periprosthetic joint infection. LAF is protective against the negative influence of number of people and door openings

Diagnosis of periprosthetic joint infection: The promise of next-generation sequencing

Background: Next-generation sequencing is a well-established technique for sequencing of DNA and has recently gained attention in many fields of medicine. Our aim was to evaluate the accuracy of next-generation sequencing in identifying the causative organism(s) in patients with periprosthetic joint infection. Methods: In this prospective study, samples were collected from 65 revision arthroplasties (39 knees and 26 hips) and 17 primary arthroplasties (9 hips and 8 knees). Synovial fluid, deep tissue, and swabs were obtained at the time of the surgical procedure and were shipped to the laboratory for next-generation sequencing. Deep-tissue specimens were also sent to the institutional laboratory for culture. Sensitivity and specificity were calculated for next-generation sequencing, using the Musculoskeletal Infection Society (MSIS) definition of periprosthetic joint infection as the standard. Results: In 28 revisions, the cases were considered to be infected; cultures were positive in 17 cases (60.7% [95% confidence interval (CI), 40.6% to 78.5%]), and next-generation sequencing was positive in 25 cases (89.3% [95% CI, 71.8% to 97.7%]), with concordance between next-generation sequencing and culture in 15 cases. Among the 11 cases of culture-negative periprosthetic joint infection, next-generation sequencing was able to identify an organism in 9 cases (81.8% [95% CI, 48.2% to 97.7%]). Next-generation sequencing identified microbes in 9 (25.0% [95% CI, 12.1% to 42.2%]) of 36 aseptic revisions with negative cultures and in 6 (35.3% [95% CI, 14.2% to 61.7%]) of 17 primary total joint arthroplasties. Next-generation sequencing detected several organisms in most positive samples. However, in the majority of patients who were infected, 1 or 2 organisms were dominant. Conclusions: Next-generation sequencing may be a useful adjunct in identification of the causative organism(s) in culture-negative periprosthetic joint infection. Our findings suggest that some cases of monomicrobial periprosthetic joint infection may have additional organisms that escape detection when culture is used. Further study is required to determine the clinical implications of isolated organisms in samples from patients who are not thought to be infected. Level of Evidence: Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence

The efficacy of aspirin versus low‐molecular‐weight heparin for venous thromboembolism prophylaxis after knee and hip arthroplasty: A systematic review and meta‐analysis of randomized controlled trials

Purpose: The purpose of this study was to assess the efficacy of aspirin versus low‐molecular‐weight heparin (LMWH) in preventing venous thromboembolism (VTE) following hip and knee arthroplasty. Methods: PubMed/Medline, Embase, Cochrane Library and Google Scholar databases were searched from inception till June 2024 for original trials investigating the outcomes of aspirin versus LMWH in hip and knee arthroplasty. The primary outcome was VTE. Secondary outcomes included minor and major bleeding events, and postoperative mortality within 90 days. This review was conducted per the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. Results: A total of 7 randomized controlled trials with 12,134 participants were included. The mean ages for the aspirin and LMWH cohorts were 66.6 (57.6–69.0) years and 66.8 (57.9–68.9) years, respectively. There was no statistically significant difference in the overall risk of VTE between the aspirin and the LMWH cohorts (odds ratio [OR]: 0.95; 95% confidence interval [CI]: 0.48–1.89; p: 0.877). A subanalysis based on the specific VTE entity (pulmonary embolism [PE] or deep venous thrombosis) showed a significantly higher PE risk for patients receiving aspirin than the LMWH cohort (OR: 1.79; 95% CI: 1.11–2.89; p: 0.017). There was no difference in minor (OR: 0.64; 95% CI: 0.40–1.04; p: 0.072) and major bleeding (OR: 0.77; 95% CI: 0.40–1.47; p: 0.424) episodes across both groups. Furthermore, subanalysis among the total knee arthroplasty group showed that the aspirin cohort was significantly more likely to suffer VTEs than their LMWH counterparts (OR: 1.55; 95% CI: 1.21–1.98; p < 0.001). Conclusion: This study demonstrated a significantly higher risk of PE among patients receiving aspirin compared to LMWH following hip or knee arthroplasty for osteoarthritis. Aspirin was associated with a significantly higher overall VTE risk among patients undergoing knee arthroplasty, in particular. This might suggest the inferiority of aspirin compared to LMWH in preventing VTE following such procedures. Level of Evidence: Level I

Mortality and adverse joint outcomes following septic arthritis of the native knee:a longitudinal cohort study of patients receiving arthroscopic washout

BACKGROUNDThe short and long-term consequences of septic arthritis are uncertain. The purpose of this study was to determine the risk of mortality and adverse joint outcomes following septic arthritis of the native knee.METHODSA retrospective cohort study of patients undergoing knee washout for septic arthritis, without prior knee surgery, was performed utilising the national hospital database for England over twenty-years. The rate of mortality within 90-days, and the 1-year and long-term rate of adverse joint outcomes (arthrodesis, amputation, arthroplasty), was determined. The mortality rate for patients with a primary admitting diagnosis of septic arthritis (ICD-10; M00) was compared to cases where this was a secondary diagnosis.FINDINGS12132 patients were included (mean age 56.6 years; SD 24.9; 36% [4307/12132] female). Of the 10195 (84%) cases with septic arthritis as the primary admitting diagnosis, the 90-day mortality rate was 7.05% (719/10195; 95% CI 6.56-7.57) rising to 22.69% (418/1842; 95% CI 20.80-24.68) for patients aged over 79-years. Secondary septic arthritis was associated with adjusted odds for mortality of 2.10 (odds ratio; 95% CI1.79-2.46; p&lt;0.001). The 1-year rate of arthrodesis was 0.13% (15/11393; 95% CI 0.07-0.22), amputation 0.40% (46/11393; 95% CI 0.30-0.54), and arthroplasty 1.33% (152/11393; 95% CI 1.13-1.56). Within 15-years, 8.76% (159/1816; 95% CI 7.50-10.15) underwent arthroplasty, corresponding to an annual risk of 6.14 times (risk ratio; 95% CI 4.95-7.62; p&lt;0.001) that of the general population.INTERPRETATIONThe consequences of septic knee arthritis (in a cohort of patients undergoing arthroscopic knee washout) are serious, with a 7% risk of mortality within 90-days, greater than 1% risk of adverse joint outcomes within 1-year, and 9% risk of knee arthroplasty within 15-years. These findings highlight the potentially devastating outcomes associated with sepsis from musculoskeletal joint infection

The impact of patient specific instrumentation on unicompartmental knee arthroplasty: A prospective randomised controlled study

Purpose Patient specific instrumentation (PSI) has been proposed as a means of improving surgical accuracy and ease of implantation during technically challenging procedures such as unicompartmental knee arthroplasty (UKA). The purpose of this prospective randomised controlled trial (RCT) was to compare the accuracy of implantation and functional outcome of mobile bearing medial UKA s implanted with and without PSI by experienced UKA surgeons. Methods Mobile-bearing medial UKA s implanted were implanted in 43 patients using either PSI guides or conventional instrumentation. Intra-operative measurements, meniscal bearing size implanted, and post-operative radiographic analyses were performed to assess component positioning. Functional outcome was determined using the Oxford Knee Score (OKS). Results PSI guides could not be used in 3 cases due to concerns regarding accuracy and registration onto native anatomy, particularly on the tibial side. In general, similar component alignment and positioning was achieved using the two systems (n.s. for coronal/sagittal alignment and tibial coverage). The PSI group had greater tibial slope (p=0.029). The control group had a higher number of optimum size meniscal bearing inserted (95% versus 52%; p=0.001). There were no differences in OKS improvements (n.s). Conclusions Component positioning for the two groups was similar for the femur but less accurate on the tibial side using PSI, often with some unnecessarily deep resections of the tibial plateau. Although PSI was comparable to conventional instrumentation based on OKS improvements at 12-months, we continue to use conventional instrumentation for UKA at our institution until further improvements to the PSI guides can be demonstrated