No exponential rise in revision knee replacement surgery over the past 15 years: an analysis from the National Joint Registry.

OBJECTIVE: To investigate trends in the incidence rate and the main indication for revision knee replacement (rKR) over the past 15 years in the UK. METHOD: Repeated national cross-sectional study from 2006 to 2020 using data from the National Joint Registry (NJR). Crude incidence rates were calculated using population statistics from the Office for National Statistics. RESULTS: Annual total counts of rKR increased from 2,743 procedures in 2006 to 6,819 procedures in 2019 (149% increase). The incidence rate of rKR increased from 6.3 per 100,000 adults in 2006 (95% CI 6.1 to 6.5) to 14 per 100,000 adults in 2019 (95% CI 14 to 14) (122% increase). Annual increases in the incidence rate of rKR became smaller over the study period. There was a 43.6% reduction in total rKR procedures in 2020 (during the Covid-19 pandemic) compared to 2019. Aseptic loosening was the most frequent indication for rKR overall (20.7% procedures). rKR for aseptic loosening peaked in 2012 and subsequently decreased. rKR for infection increased incrementally over the study period to become the most frequent indication in 2019 (2.7 per 100,000 adults [95% CI 2.6 to 2.9]). Infection accounted for 17.1% first linked rKR, 36.5% second linked rKR and 49.4% third or more linked rKR from 2014 to 2019. CONCLUSIONS: Recent trends suggest slowing of the rate of increase in the incidence of rKR. Infection is now the most common indication for rKR, following recent decreases in rKR for aseptic loosening. Infection was prevalent in re-revision KR procedures.

Comparison of Operating Room Air Quality in Primary Versus Revision Total Knee Arthroplasty.

BACKGROUND: Airborne biologic particles (ABPs) can be measured intraoperatively to evaluate operating room (OR) sterility. Particulate matter (PM) up to 2.5 microns can contain microbial species which may increase infection risk. Our study examines the differences in air quality and ABP count in primary total knee arthroplasty (TKA) and revision TKA (rTKA). METHODS: We analyzed primary and rTKAs in a single OR at an academic institution from January 2020 to December 2020. Procedures from March 15, 2020, to May 4, 2020, were excluded to avoid COVID-related confounding. Temperature, humidity, and ABP count per minute were recorded with a particle counter intraoperatively and cross-referenced with surgical data from the electronic health records using procedure start and end times. Descriptive statistics were used to evaluate the differences in variables. P values were calculated using t-test and chi-square test. RESULTS: A total of 107 TKA cases were included: 79 (73.8%) primary TKAs and 28 (26.2%) rTKAs. Time spent in an OR was significantly higher for rTKAs (primary: 176 ± 46.7 minutes vs revision: 220 ± 47.1 minutes, P < .0001). Compared to primary TKAs, rTKAs had significant percent increases in ABP rates for particles measuring 0.3 µm (+70.4%, P < .001), 0.5 µm (+97.2%, P < .0001), 1.0 µm (+53.2%, P = .001), and 2.5 µm (+30.3%, P = .017) and for PM 2.5 (+108.3%, P < .001) and PM 5.0 (+105.6%, P < .001). CONCLUSION: rTKAs had significantly longer time spent in an OR and significant percent increases in ABP rates for particles measuring 0.3 µm, 0.5 µm, and 1.0 µm compared to primary TKAs. Measurements of PM 2.5 and 5.0 (which can contain large numbers of microbes) were also significantly greater in rTKAs. Further research is needed to determine whether the size and quantity of ABPs translate to higher infection rates after rTKA.

A Cadaveric Study Addressing the Feasibility of Remote Patient Monitoring Prosthesis for Total Knee Arthroplasty.

BACKGROUND: Since the COVID-19 pandemic of 2020, there has been a marked rise in the use of telemedicine to evaluate patients after total knee arthroplasty (TKA). The purpose of our study was to assess a novel stem with an embedded sensor that can remotely and objectively monitor a patient's mobility after TKA. METHODS: A single anatomically designed knee system was implanted in concert with an interconnected tibial stem extension containing 3D accelerometers, 3D gyroscopes, a power source, and a telemetry transmission capability in 3 cadaveric pelvis to toe specimens. The legs were moved by hand to preset tibial positions at full knee extension, midflexion, flexion, and back to midflexion and extension for a total of 16 trials across 6 knees. RESULTS: Sensor data were successfully transmitted with good quality of signal to an external base station. Good correlation to the range of motion of the tibia was found (mean error 0.1 degrees; root mean square error 3.8 degrees). The signal from the heel drop tests suggests the sensor could detect heel strike during activities of daily living in vivo and the potential for additional signal processing to analyze vibratory and motion patterns detected by the sensors. A frequency domain analysis of a properly cemented and poorly cemented implant during the heel drop test suggests a difference in accelerometer signal in these implant states. CONCLUSION: The results confirm signals generated from an embedded TKA sensor can transmit through bone and cement, providing accurate range of motion data and may be capable of detecting changes in prosthesis fixation remotely.

Impact of microprocessor prosthetic knee on mobility and quality of life in patients with lower limb amputation: a systematic review of the literature.

INTRODUCTION: Advanced technologies have made available the development of microprocessor prosthetic knee (MPK) to improve autonomy of patients with lower limb amputation. In the present systematic review, we aimed to evaluate the impact of the use of all types of MPK on patients' functional status and quality of life. EVIDENCE ACQUISITION: We conducted this review according to the PRISMA Guidelines on Medline (via Ovid), Scopus and SportDiscuss. All identified articles were screened for their eligibility by two reviewers using Covidence software. The Cochrane Risk of Bias (RoB) or the NIH Quality Assessment Tool were used to assess the quality of the studies. EVIDENCE SYNTHESIS: Eighteen articles were included in the present review (7 randomized controlled trials - RCT), 6 cross-sectional and 5 follow-up studies). Number of participants included varied from 20 to 602, protocols' length varied from a single session to 12 weeks of use of MPK. Taken together, MPK users compared to NMPK users tend to present better functional status and mobility. Quality of life was also positively impacted in MPK users. On the other hand, the superiority of more advanced MPKs such as the Genium® is less clear, especially given the improvements over time of other MPKs such as the C-leg® and the Rheo knee®. CONCLUSIONS: Based on our results, while it is clear that MPKs outperform NMPKs both for functional status and quality of life, additional benefits of one MPK over another is less clear. Future studies are needed to clarify these aspects.

Clinical prioritisation of revision knee surgical procedures: BASK working group consensus document.

BACKGROUND: Elective orthopaedic surgery during the Covid-19 pandemic requires careful case prioritisation. We aimed to produce consensus-based guidelines on the prioritisation of revision total knee arthroplasty (TKA) procedures. METHOD: Twenty-three revision TKA scenarios were assigned priority (NHS England/Royal College of Surgeons scale) by the British Association for Surgery of the Knee (BASK) Revision Knee Working Group (n = 24). Consensus agreement was defined as ≥70% respondents (18/24) giving the same prioritisation. Two voting rounds were undertaken; procedures achieving <70% agreement were given their most commonly assigned priority. RESULTS: 18/23 procedures achieved ≥70% agreement. Three were P1a (surgery within <24 h); DAIR for sepsis, peri-prosthetic fracture (PPF) fixation and PPF-revision TKA. Three were P1b (<72 h); debridement, antibiotics and implant retention (DAIR) for a stable patient, flap coverage for an open knee, and acute extensor mechanism rupture. Eight were P2 (<4 weeks), including aseptic loosening at risk of collapse, inter-stage patients with poor functioning spacers. Five were P3 (<3 months), including second stage revision for infection, revision for instability with limited mobility. Four were P4 (can wait >3 months) e.g. aseptic loosening. CONCLUSION: Sepsis and PPF surgery are the most urgent procedures. Although most procedures should be undertaken within one to three months (P2/3), these cases represent a small revision practice volume; P4 cases (e.g. aseptic loosening without risk of collapse) make up most surgeons' caseload. These recommendations are a guideline; patient co-morbidities, Covid-19 pathways, availability of support services and multi-disciplinary team discussion within the regional revision network will dictate prioritisation.

Surgical Treatment of Acute Periprosthetic Knee Infection with Concurrent Presumed COVID-19: A Case Report.

CASE: We report the case of a 64-year-old man who presented with a late onset of acute periprosthetic joint infection after total knee arthroplasty and a positive severe acute respiratory syndrome coronavirus 2 polymerase chain reaction test. We describe our perioperative protocol and challenges for ensuring the safety of healthcare providers while operating on a coronavirus disease 2019 (COVID-19)-positive patient. CONCLUSIONS: Given the incredible spread of COVID-19 globally, hospitals should anticipate perioperative protocols for the surgical management of COVID-19-positive patients with concurrent pathology to ensure safety to healthcare providers.