Revision Total Knee Replacement Research Articles

My orthopaedic surgeon suggests a unicompartmental knee replacement: a detailed look at the long-term outcomes of a single surgeon's practice.

This single surgeon case series with up to 29-year follow-up evaluated the survival of the Oxford unicompartmental knee replacement (UKR) for isolated medial compartment osteoarthritis. Four hundred and four knees in 330 patients were followed for between 12 days to 29 years, with an average of 13 years. Kaplan-Meier survival estimates were calculated using revision for total knee replacement and re-operation for any reason over 5-year intervals. Revision and reoperation rates per 100 component years were used to compare subsets, cemented and uncemented prostheses and Phase 2 and Phase 3 instrumentation. Of 404 UKRs, 292 (72%) were cemented, 96 (24%) uncemented and 16 hybrid (4%); 137 (34%) were undertaken using Phase 2 instrumentation and 267 (66%) Phase 3 instrumentation. Estimated revision-free implant survival at 20 years was 78%, and estimated reoperation-free survival at 20 years was 72%. Unicompartmental knee replacement is a very successful procedure, with 78% of knees remaining revision-free at 20 years. Progression of lateral compartment arthritis was the most common cause for revision, affecting 60% of revision cases. There was no significant difference in the revision or reoperation rate between cemented and uncemented prostheses or Phase 2 and minimally invasive Phase 3 instrumentation.

Revision total knee replacement finances: a detailed cost-analysis of operative practice at a regional tertiary referral centre

BackgroundThe revision knee complexity classification (RKCC) stratifies knee revision operations depending on their level of complexity from simple revisions (R1) to highly complex cases (R3). Current financial codes used for calculation of reimbursement for knee revision services provided at the Trust, rely on patients’ comorbidities. However, previous research has demonstrated that this approach may not yield an accurate financial account of knee revision arthroplasty cost. This is a single centre study from a secondary and tertiary revision unit, with work previously presented by the authors demonstrating that the majority of complex revision knee replacement within the region, take place in this unit. The aims of this study were to illustrate the current cost profile and renumeration service currently in place for revision knee and show the differences in cost based on complexity of the operation.MethodsIn this retrospective study, 90 cases who underwent revision knee operations in 2019 were analysed. Data was obtained from a tertiary referral centre where the episodes had occurred. Mean cost, tariff, and subsequent deficit were calculated for the R1, R2 and R3 episodes.ResultsR2 and R3 episodes were significantly more expensive than R1 episodes. The increase in cost between R3 and R2 episodes was not significant. The total cost of the revision operations was £1,162,343. Tariffs received for R2 and R3 revision operations were significantly more expensive than R1 operations. However, the increase in tariffs received for R3 operations was not significant in relation to R2 operations. The total amount of tariffs received by the Trust was £ 770,996 generating a net deficit of - £ 391,347.ConclusionCurrent financial coding for revision knee does not accurately predict costs associated with revision knee surgery. Net deficit varies depending on the RKCC grade of the knee revision episode with more complex operations resulting in a higher mean net deficit. Implementation of the RKCC could prove to be a useful tool in generating an accurate prediction of the cost associated with knee revision surgery.

Unicompartmental knee replacement combined with anterior cruciate ligament reconstruction provides comparable results to total knee replacement with no increased risk of complications.

There is controversy about the management of unicompartmental knee osteoarthritis (OA) in young, active patients with anterior cruciate ligament (ACL) insufficiency. This study compares the subjective, radiological, and functional results of total knee replacement (TKR) vs. combined medial unicompartmental knee replacement (UKR) with ACL reconstruction. Twelve patients suffering from medial OA and ACL deficiency with varus knee deformity and/or tibial slope<10° and absence of patellofemoral-related problems were eligible for combined UKR and ACL reconstruction (Group A). Twenty-six patients matched for age, male/female ratio and body mass index who received TKR in the same time frame were included as a control group (Group B). Oxford Knee Score (OKS), WOMAC index of osteoarthritis, Knee Osteoarthritis Outcome Score (KOOS), and routine X-rays were used for assessment. Ten years after surgery, the mean overall KOOS score, OKS, WOMAC index increased from preoperatively, showing a statistically significant difference (p<0.001). In terms of KOOS, OKS, or WOMAC scores at the most recent follow-up, there was no discernible difference between the groups (p=n.s.). Three years following surgery, one female patient in group A received revision TKR due to the lateral compartment's osteoarthritis developing and the patient's pain persisting. Concerning radiographic assessment, at the most recent follow-up (average 7.9years in group A and 8.8years in group B), there were no radiographic indications of implant loosening or proof of pathologic radiolucent lines. UKR combined with ACL restoration offers clinical and radiographic outcomes comparable to TKR 10years following surgery with no elevated risk of complications.

A comparison of joint line height after revision total knee replacement using a rotating hinge versus a condylar revision knee system

PurposeThis retrospective study aimed to assess the effects of two differing revision total knee implants designs (condylar and rotating hinge) on joint line height. MethodThe use of distal augmentation and pre and post revision radiographic joint line heights were compared in 19 condylar type knee replacements (Zimmer NexGen Legacy Constrained Condylar Knee - LCCK) and 40 LINK-Endo-rotating hinge knee replacements. Joint line and patellar heights were determined for each implant using four validated methods. For comparison within a group a two tailed paired Student's t-test was used, for comparison between the groups an unpaired, two tailed Student's t-test was used. A p value of less than 0.05 was deemed statistically significant. ResultsIn 15 of 19 NexGen revision knee replacements distal augments were used. No distal augments were used in the LINK-Endo RHK group. In both systems there was no tendency to elevate the joint line relative to the tibia. The joint line was distalised relative to the femur in the NexGen group and proximalised in the rotating hinge knee group. Measurements using antero-posterior radiographs were found to be the most reliable method of assessing joint line height when compared to lateral radiographs. ConclusionBoth revision knee implant systems adequately restored joint line height. In condylar type knee revision implants elevation of the joint line height may be avoided through the use of distal augmentation. We found AP radiographs to be the most reliable method of accurately assessing joint line height.

Frequent microbiological profile changes are seen in subsequent-revision hip and knee arthroplasty for prosthetic joint infection.

A proportion of patients with hip and knee prosthetic joint infection (PJI) undergo multiple revisions with the aim of eradicating infection and improving quality of life. The aim of this study was to describe the microbiology cultured from multiply revised hip and knee replacement procedures to guide antimicrobial therapy at the time of surgery. Patients and methods: Consecutive patients were retrospectively identified from databases at two specialist orthopaedic centres in the United Kingdom between 2011 and 2019. Patient were included who had undergone repeat-revision total knee replacement (TKR) or total hip replacement (THR) for infection, following an initial failed revision for infection. Results: A total of 106 patients were identified. Of these patients, 74 underwent revision TKR and 32 underwent revision THR. The mean age at first revision was 67years (SD 10). The Charlson comorbidity index was 2 for 31 patients, 3-4 for 57 patients, and 5 for 18 patients. All patients underwent at least two revisions, 73 patients received three, 47 patients received four, 31 patients received five, and 21 patients received at least six. After six revisions, 90 % of patients had different organisms cultured compared with the initial revision, and 53 % of organisms were multidrug resistant. The most frequent organisms at each revision were coagulase-negative Staphylococcus (36 %) and Staphylococcus aureus (19 %). Fungus was cultured from 3 % of revisions, and 21 % of infections were polymicrobial. Conclusion: Patients undergoing multiple revisions for PJI are highly likely to experience a change in organism, with 90 % of patients having a different organism cultured by their sixth revision. It is therefore important to administer empirical antibiotics at each subsequent revision, taking into account known drug resistance from previous cultures. Our results do not support the routine use of empirical antifungals.

No difference in the use of revision components and rerevision rate in conversion to total knee replacement following Oxford Partial Knee Microplasty Instrumentation: a registry study of 529 conversions.

Microplasty Instrumentation was introduced to improve Oxford Mobile Partial Knee placement and preserve tibial bone in partial knee replacement (PKR). This might therefore reduce revision complexity. We aimed to assess the difference in use of revision total knee replacement (TKR) tibial components in failed Microplasty versus non-Microplasty instrumented PKRs. Data on 529 conversions to TKR (156 Microplasty instrumented and 373 non-Microplasty instrumented PKRs) from the Dutch Arthroplasty Register (LROI) between 2007 and 2019 was used. The primary outcome was the difference in use of revision TKR tibial components during conversion to TKR, which was calculated with a univariable logistic regression analysis. The secondary outcomes were the 3-year re-revision rate and hazard ratios calculated with Kaplan-Meier and Cox regression analyses. Revision TKR tibial components were used in 29% of the conversions to TKR after failed Microplasty instrumented PKRs and in 24% after failed non-Microplasty instrumented PKRs with an odds ratio of 1.3 (CI 0.86-2.0). The 3-year re-revision rates were 8.4% (CI 4.1-17) after conversion to TKR for failed Microplasty and 11% (CI 7.8-15) for failed non-Microplasty instrumented PKRs with a hazard ratio of 0.77 (CI 0.36-1.7). There was no difference in use of revision tibial components for conversion to TKR or in re-revision rate after failed Microplasty versus non-Microplasty instrumented PKRs nor in the 3-year revision rate.

The Role of Constraint in Revision Total Knee Replacement for Instability: Full Component Revision Vs Isolated Polyethylene Exchange in Selected Patients.

Instability is a common indication for revision after total knee arthroplasty. Replacement of multiple components is the current standard, but isolated polyethylene liner exchange (IPE) may present a less-morbid alternative. This study aims to determine (1) whether IPE results in similar rerevision frequency to component revision in select patients with symptomatic instability and (2) the effect of increasing constraint on the outcome. We retrospectively reviewed 117 patients revised for symptomatic total knee arthroplasty instability from January 2016 to December 2017. The component revision (60 patients) or IPE (57 patients) cohorts were further stratified based on whether constraint was increased or not. The primary objective was to compare rerevision rates 2 years after component revision vs IPE. The secondary objectives consisted of evaluating reasons for rerevision, preoperative and postoperative patient-reported outcome measures, and range of motion. The rerevision rate was 18%, with no statistical difference between component and IPE cohorts. Cases where level of constraint increased due to revision, a significantly lower rate of rerevision was detected (9 of 77) (12%) than in cases where constraint did not increase (12 of 39) (31%) (P=0.012). This association was also noted in the component revision cohort but not in the IPE cohort (P=0.011). Rerevision occurred at similar frequencies 2 years after IPE or component revision for total knee arthroplasty instability. For component revision, increased constraint was associated with significantly fewer rerevisions.

Constraint degree in revision total knee replacement: a registry study on 1432 patients

PurposeTotal knee replacement (TKR) failure represents a hard challenge for knee surgeons. TKR failure can be managed in revision with different constraint, related with soft and bone knee damages. The choice of the right constraint for every failure cause represents a not summarized entity. The purpose of this study is identifying distribution of different constraints in revision TKR (rTKR) for failure cause and the overall survival.MethodsA registry study based on the Emilia Romagna Register of the Orthopaedic Prosthetic Implants (called RIPO) was performed with a selection of 1432 implants, in the period between 2000 and 2019. Selection implants including primary surgery constraint, failure cause and constraint revision for every patient, and divided for constraint degrees used during procedures (Cruciate Retaining-CR, Posterior Stabilized-PS, Condylar Constrained Knee-CCK, Hinged).ResultsThe most common cause of primary TKR failure was aseptic loosening (51,45%), followed by septic loosening (29,12%). Each type of failure was managed with different constraint, the most used was CCK in the most of failure causes, such as to manage aseptic and septic loosening in CR and PS failure. Overall survival of TKA revisions has been calculated at 5 and 10 years for each constraint, with a range of 75.1–90.0% at 5 years and 75.1–87.5% at 10 years.ConclusionConstraint degree in rTKR is typically higher than primary, CCK is the most used constraint in revision surgery with an overall survival of 87.5% at 10 years.

Patients undergoing revisions for total knee replacement malposition are younger and more often female: An analysis of data from the Dutch Arthroplasty register

BackgroundThe proportion of patients who are dissatisfied with the outcome following total knee replacement (TKR) is high. Malalignment is considered a probable cause for persistent pain, but whether this reason for revision could be the result of specific patient characteristics remains unclear. Therefore, we aim to assess whether specific patient characteristics are associated with revision for symptomatic TKR malalignment. MethodsData was obtained from the Dutch Arthroplasty Register (LROI), which contains data from all Dutch hospitals. All patients who underwent TKR revision surgery between 2008 and 2019 were included in this study. The (primary) reason for revision as well as patient characteristics (age, gender, ASA classification, and pre-operative patient-reported outcome measures) were abstracted. The Chi-square test for categorical variables, and ANOVA or Kruskal-Wallis for continuous variables were used to determine differences in patient characteristics between the subgroups based on reason for revision. ResultsA total of 11,044 TKR revisions were registered in The Netherlands between 2008 and 2019. Malalignment was registered as the primary reason for revision in 13% of the patients. Subgroup analyses showed that patients who underwent TKR revisions for malalignment where younger (63.8 year, SD ± 9.3) and more often female (70%) compared to other major reasons for TKR revisions. ConclusionPatients who had a TKR revision for malalignment were younger and more often female. This suggests that patient characteristics may play a role when reasons to perform revision surgery are considered. Surgeons should invest in the expectation management in (young) patients and inform patients of these potential risk factors as part of shared decision-making.

RISK FACTORS OF INFECTION IN TOTAL KNEE ARTHROPLASTY

To determine risk factors of infection in total knee arthroplastyThis descriptive study was conducted in the Department of Orthopedics for a duration of three years from January 2016 to January 2019. All patients undergoing primary total knee replacement were included in the study. Exclusion criteria were all patients operated in another hospital and revision total knee replacement. All patients were followed up at 2, 4, 8, 12 and 24 weeks post-operatively. Signs of inflammation and inflammatory markers such as total leukocyte count (TLC), C-reactive protein (CRP) and ESR were measured. Risk factors like age, body mass index (BMI), ASA, co-morbid conditions were also noted.A total of 78 patients underwent primary unilateral Total Knee Replacement (TKR) during the study period. Of these, 30 (34.09%) were male and 48 (61.54%) female patients. Mean age of patients was 68.32 ± 8.54 years. Average BMI 25.89 Kg/m2 .Osteoarthritis was the pre-dominant cause of total knee replacement (94.87%). Among co-morbid factors 33.33% were diabetic, 28.20% having ischemic heart disease and 12.82% with chronic lung disease. Upon anaesthesia fitness pre-operatively, 91.02% patients had an American society of anaesthesiologist score (ASA) between 0–2 while 07 (8.97%) between 3- 5. Average duration of surgery was 85.62± 4.11 minutes. 6.41% cases got infected. In majority of the infected cases (60%), Staphylococcus aureus was the infective organism. Diabetes Mellitus (p=0.01) and Obesity (p=0.02) had a significant relation to post-operative infection.Pre-operative risk evaluation and prevention strategies along with early recognition of infection and control can greatly reduce the risk of joint infection post-TKR which will not only improve the mobility of patient but also its morbidity and mortality as well.Key Words:C-reactive protein (CRP), Erythrocyte Sedimentation Rate (ESR), Staphylococcus aureus, Total Knee Arthroplasty (TKA)

Antibiotic Prophylaxis in One-Stage Revision of Septic Total Knee Arthroplasty: A Scoping Review

Total knee replacement (TKA) is becoming a routine procedure in orthopedic surgery. One of the possible complications of this surgery is periprosthetic joint infection (PJI). The purpose of this study is to identify, through a literature review, which antibiotic is used as prophylaxis for septic one-stage revision TKA and what is the rationale for its use. We searched: MEDLINE, Embase, PsycINFO on Ovid, the Cochrane Library, and the Google Scholar Database. The searches were limited by date (January 2005 to September 2022) and to the English language. All types of original research were considered, including prospective or retrospective longitudinal studies, cross-sectional studies, and randomized trials. The specific search terms were ((antibiotic [MeSH]) AND (prophylaxis)) and (TKA OR TKR OR "Arthroplasty, Replacement, Knee" [MeSH] OR ((knee) adj2 (replace* OR arthroplasty* OR prosthe*))). Despite our research efforts, we found no article capable of answering the question of which antibiotic to use as surgical prophylaxis for a septic revision one-stage TKA. Although the research results are inconclusive, we would recommend using the same antibiotic prophylaxis as for primary joint replacement, i.e., cefazolin, as it was recommended for its low side effect rate and relative effectiveness.

Circular external fixation for knee fusion in complex indications.

Reconstructive surgery for complex knee problems is limited and challenging. The aim of this study is to report the technique, outcomes and complications of circular external fixation for knee fusion in complex indications. Retrospective review of a prospectively collected database of a complex limb reconstruction unit was done during December 2022. Patients with complex knee problems who underwent knee fusion with circular external fixator were included. Fourteen patients met the inclusion criteria. The mean age of the patients was 63 ± 16.8years. Deep infection was the indication for surgery in 11 patients (78.5%), of which 10 cases were related to previously failed revision arthroplasty. The mean duration of treatment in frame was 13 ± 4.1months, while the mean follow-up duration following frame removal was 7.1 ± 4.2years. Fusion was achieved in 13 patients (92.9%). The most common complication was pin site infection (6; 42.9%), of which three (21.4%) required pin/wire revision. One (7.1%) patient had fracture at the fusion site following frame removal that was treated with reapplication of the frame. Knee fusion using circular external fixation is a reliable surgical option for complex knee problems especially in infected failed revision total knee replacements.

Rehabilitation for revision total knee replacement: survey of current service provision and systematic review

BackgroundRevision total knee replacement (TKR) is a major operation with a long recovery period and many patients report suboptimal outcomes. Rehabilitation has the potential to improve outcomes. The aim of this study was to understand current provision of rehabilitation for revision TKR in England and evaluate the existing evidence.MethodsPhase 1: An online national survey of education and rehabilitation provision for patients receiving revision TKR was completed by physiotherapy staff at 22 hospitals across England that were high volume for revision TKR (response rate of 34%).Phase 2: Systematic review to identify studies evaluating rehabilitation programmes for revision joint replacement. Searches were conducted in MEDLINE, EMBASE, PsycINFO, CINAHL, and Cochrane databases from inception to 15th June 2022. Randomised controlled trials (RCTs) and observational studies that evaluated post-operative rehabilitation for adults undergoing revision joint replacement were included. Screening, data extraction and quality assessment was undertaken by two reviewers.ResultsPhase 1: Pre-operative education which aimed to prepare patients for surgery and recovery was provided in most hospitals, predominately involving a single session delivered by a multidisciplinary team. Inpatient physiotherapy commonly commenced on post-operative day 1 and was provided twice daily, with most hospitals also providing occupational therapy. Rehabilitation was often provided in the first four weeks after hospital discharge, either in an outpatient, community or home setting. In most hospitals, the education and rehabilitation provided to patients receiving revision TKR was the same as that provided to patients undergoing primary TKR.Phase 2: Of the 1,445 articles identified, three retrospective cohort studies based on hospital records review were included. The studies evaluated intensive inpatient rehabilitation programmes, consisting of 2–3 h of daily group or individual physiotherapy, with additional occupational therapy in one study. All three studies reported improvement in functional outcomes for patients undergoing rehabilitation after revision TKR. All studies were limited by their retrospective design, short duration of follow-up and lack of sample size calculation. No RCTs evaluating effectiveness of rehabilitation for revision TKR were identified.ConclusionThis study identified the need for future research to develop and evaluate tailored rehabilitation to optimise patient outcomes following revision TKR.

THE EFFECT OF SURGEON VOLUME AND RISK OF REVISION FOLLOWING TOTAL KNEE ARTHROPLASTIES WITH AND WITHOUT PATELLAR RESURFACING: A STUDY FROM THE AUSTRALIAN ORTHOPAEDIC ASSOCIATION NATIONAL JOINT REPLACEMENT REGISTRY

Strategy regarding patella resurfacing in total knee replacement (TKR) remains controversial. TKR revision rates are reportedly influenced by surgeon procedure volume. The study aim was to compare revision outcomes of TKR with and without patella resurfacing in different surgeon volume groups using data from the AOANJRR.The study population included 571,149 primary TKRs for osteoarthritis. Surgeons were classified as low, medium, or high-volume based on the quartiles of mean primary TKR volume between 2011 and 2020. Cumulative percent revision (CPR) using Kaplan-Meier estimates of survivorship were calculated for the three surgeon volume groups with and without patella resurfacing. Cox proportional hazards models, adjusted for age and sex, were used to compare revision risks.High-volume surgeons who did not resurface the patella had the highest all-cause CPR (20-year CPR 10.9%, 95% CI [10.0%, 12.0%]). When the patella was resurfaced, high-volume surgeons had the lowest revision rate (7.3%, 95% CI [6.4%, 8.4%]). When the high-volume groups were compared there was a higher rate of revision for the non-resurfaced group after 6 months. When the medium-volume surgeon groups were compared, not resurfacing the patella also was associated with a higher rate of revision after 3 months. The low-volume comparisons showed an initial higher rate of revision with patella resurfacing, but there was no difference after 3 months. When only patella revisions were considered, there were higher rates of revision in all three volume groups where the patella was not resurfaced.TKR performed by high and medium-volume surgeons without patella resurfacing had higher revision rates compared to when the patella was resurfaced. Resurfacing the patella in the primary procedure protected against revision for patella reasons in all surgeon volume groups.Level of evidence: III (National registry analysis)

How often do we need offset stems for revision total knee arthroplasty? About a consecutive series of 789 knees.

This study aimed to determine the incidence of offset stem usage in revision total knee arthroplasty (rTKA), and to assess the necessity for their use with the femoral and tibial components. This retrospective radiological study included 862 patients who underwent rTKA between 2010 and 2022. Patients were divided into a non-stem group (group NS), offset stem group (group OS), and straight stem group (group SS). Two senior orthopedic surgeons evaluated all the post-operative radiographs of the group OS to assess the necessity of offset use. In total, 789 patients met all eligibility inclusion criteria and were reviewed (305 males (38.7%)) with a mean age of 72.7 ± 10.2years old [39; 96]. Eighty-eight (11.1%) patients had undergone rTKA with offset stems (34 tibia, 31 femur, 24 both) and 609 (70.2%) with straight stems. The tibial and femoral stems were diaphyseal of over 75mm in 83 revisions (94.3%) for group OS and 444 revisions (72.9%) for group SS (p<0.001). Offset in the tibial component was located medially in 50% of rTKA, while the offset in the femoral component was placed anteriorly in 47.3% of the rTKA. Assessment by the two independent senior surgeons found stems were only necessary in 3.4% of cases. Offset stems were only required for the tibial implant. Offset stems were used in 11.1% of revision total knee replacements, however, they were deemed necessary in 3.4% and for the tibial component only.

What's New in Adult Reconstructive Knee Surgery.

What's New in Adult Reconstructive Knee Surgery.

Regional economic burden of revision total knee replacement: A cost-complexity analysis

BackgroundGIRFT tasked regional networks with addressing case-load, complexity-spread and cost of revision knee replacement (KR), but the regional cost burden is not clear. The tariff for revision KR is currently not dependent on surgical complexity. 2 years of revision KR complexity data using the validated Revision Knee Complexity Classification (RKCC) checklist as a demonstration of complexity spread in the region has previously been published. The aims of this study were to estimate the annual regional cost of revision TKR using existing data, and estimate the cost/saving of complexity-clustering using existing data from 8 revision centres. MethodsFinancial data from the regional high-volume centre for one year (2019) of RKCC data collection was obtained. Mean cost, tariff and balance was calculated for R1, R2 and R3 (RKCC), and applied to data from each revision centre to provide local estimates. Complexity clustering was considered using 3 hypothetical scenarios of high-volume centre absorbing R2s and/or R3s in place of R1s. ResultsMean net loss was £2,290.08 for R1s, £6,471.42 for R2s and £6,454.26 for R3s. The estimated total annual loss for the region was £1,005,025. Complexity-clustering was associated with greater losses; £162,918 for high-volume centre taking R2s and R3s, £37,477.60 for taking just R3s and £125,440 for taking just R2s. ConclusionRevision TKR surgery is expensive and insufficiently remunerated with current measures. Restructuring of regional workload would create additional financial burden on specialist centres with current tariff awards structure. Managing reimbursement at a regional or central level may help to incentivise compliance with GIRFT ideals.

Repeat revision TKR for failed management of peri-prosthetic infection has long-term success but often require multiple operations: a case control study.

Prosthetic joint infection (PJI) is associated with poor outcomes and catastrophic complications. The aim of this study was to present the outcomes of re-revision surgery for PJI of the knee following previous failed two-stage exchange arthroplasty. A retrospective analysis was performed of 32 patients who underwent re-revision knee arthroplasty, having already undergone at least one previous two-stage exchange for PJI with a minimum follow-up of two-years for alive patients. Outcomes were compared to a matched control of two-stage revisions for PJI of a primary knee replacement also containing 32 patients. Outcomes investigated were eradication of infection, re-operation, mortality and limb-salvage rate. Successful eradication of infection was achieved in 50% of patients following re-revision surgery, compared with 91% following two-stage exchange of primary knee replacement for PJI (p < 0.001). Fourteen (44%) patients required further re-operation compared with three (9%) patients in the primary group (p = 0.006). Amputation was performed in one case (3%) with thirteen patients (92%) who had infection controlled by debridement, antibiotics and implant retention (DAIR), further revision surgery or arthrodesis. Two patients died with infection (6%) and the long-term rate for infection control was 91%. The mean number of procedures following surgery for the re-revision group was 2.8 (0-9) compared with 0.13 (0-1) for the primary two-stage group (p < 0.001). Five-year patient survival was 90.6% (95% CI 77.1-100). The limb-salvage rate for the re-revision cohort was 97%. Outcomes for re-revision knee arthroplasty for PJI have higher re-operation and failure rates, but no worse mortality than in revisions of primary knee replacements. Failures can successfully be managed by further operation.

Impact of patient and prosthesis characteristics on common reasons for total knee replacement revision: a registry study of 36,626 revision cases from Australia, Sweden, and USA.

Background and purposeTotal knee replacement (TKR) studies usually analyze all-cause revision when considering relationships with patient and prosthesis factors. We studied how these factors impact different revision diagnoses.Patients and methodsWe used data from 2003 to 2019 of TKR for osteoarthritis from the arthroplasty registries of Sweden, Australia, and Kaiser Permanente, USA to study patient and prosthesis characteristics for specific revision diagnoses. There were 1,072,924 primary TKR included and 36,626 were revised. Factors studied included age, sex, prosthesis constraint, fixation method, bearing mobility, polyethylene type, and patellar component use. Revision diagnoses were arthrofibrosis, fracture, infection, instability, loosening, pain, patellar reasons, and wear. Odds ratios (ORs) for revision were estimated and summary effects were calculated using a meta-analytic approach.ResultsWe found between-registry consistency in 15 factor/reason analyses. Risk factors for revision for arthrofibrosis were age < 65 years (OR 2.0; 95% CI 1.4–2.7) and mobile bearing designs (MB) (OR 1.7; CI 1.1–2.5), for fracture were female sex (OR 3.2; CI 2.2–4.8), age ≥ 65 years (OR 2.8; CI 1.9–4) and posterior stabilized prostheses (PS) (OR 2.1; CI 1.3–3.5), for infection were male sex (OR 1.9; CI 1.7–2.0) and PS (OR 1.5; CI 1.2–1.8), for instability were age < 65 years (OR 1.5; CI 1.3–1.8) and MB (OR 1.5; CI 1.1–2.2), for loosening were PS (OR 1.5; CI 1.4–1.6), MB (OR 2.2; CI 1.6–3.0) and use of ultra-high molecular weight polyethylene (OR 2.3; CI 1.8–2.9), for patellar reasons were not resurfacing the patella (OR 13.6; CI 2.1–87.2) and MB (OR 2.0; CI 1.2–3.3) and for wear was cementless fixation (OR 4.9; CI 4.3–5.5).InterpretationPatients could be counselled regarding specific age and sex risks. Use of minimally stabilized, fixed bearing, cemented prostheses, and patellar components is encouraged to minimize revision risk.

Summary of outcomes of a non-invasive biomechanical therapy for patients with knee osteoarthritis

Osteoarthritis (OA) is the second most frequent chronic musculoskeletal (MSK) condition after low back pain and a leading cause of disability in the elderly. The number of people living with disability will continue to rise with the aging of the population. Moreover, the rapid increase in rates of surgical intervention, i.e. Total knee replacement (TKR) and revision TKRs, is expected to place an immense burden on the health care system and society. There is a call for better rehabilitation, new interventions, and disease management for patients with knee OA. The purpose of this article is to review the biomechanics of knee OA and biomechanical interventions and to summarize the current literature on a non-invasive, home-based biomechanical treatment for patients with knee OA. The evidence suggests an improvement in symptoms and biomechanical indicators after using the home-based biomechanical intervention. In the presence of value-based payment to improve efficiency and effectiveness in delivering medical care, these results are promising.