A high physical activity level after total knee arthroplasty does not increase the risk of revision surgery during the first twelve years: A systematic review with meta-analysis and GRADE.

BACKGROUND: High physical activity (HPA) levels after total knee arthroplasty (TKA) might be related to increased wear and subsequent aseptic loosening, negatively affecting TKA survival. This systematic review studied the association between activity levels and risk of revision surgery at medium (3-10 years) and long term (>10 years) follow up in patients with TKA. METHODS: Databases (PubMed, Embase) were searched up to 12 October 2021. Studies comparing low physical activity (LPA) and HPA levels in TKA patients and related risk of revision surgery were eligible for inclusion. After data extraction and evaluation of methodological quality, a meta-analysis was performed. Quality of evidence was assessed using the GRADE framework. PROSPERO registration: CRD42020194284. RESULTS: Five cohort studies and one case-control study met the inclusion criteria, involving 4811 TKA procedures in 4263 patients (mean follow up 4-12 years). Five studies were of moderate methodological quality and one of low quality. Meta-analysis demonstrated no association between HPA level and an increased risk of all-cause revision surgery (risk ratio (RR) 0.62, 95 % confidence interval (CI) 0.24-1.63, level of certainty: very low) or revision surgery due to aseptic loosening (RR 1.33, 95 % CI 0.34-5.24, level of certainty: moderate). Only one study reported on survivorship, with an improved survivorship for the HPA group (odds ratio of 2.4, 95 % CI 1.2-4.7, level of certainty: low). CONCLUSION: During the first 12 postoperative years after TKA, there seems to be no increased risk for revision surgery for patients with a HPA level compared with patients with an LPA level.

Recovery of knee range of motion after total knee arthroplasty in the first postoperative weeks: poor recovery can be detected early.

PURPOSE: The aim of this study was to analyze in detail how knee flexion and extension progress in the first 8 weeks after primary total knee arthroplasty (TKA). The secondary goal was to compare knee range of motion (ROM) recovery patterns between patients with normal and delayed ROM recovery 8 weeks after TKA. METHODS: This prospective clinical trial included all patients who underwent a primary unilateral TKA between February and December 2016 with weekly ROM data documented by the treating outpatient physical therapists (n = 137). Goniometry was used to measure knee ROM preoperatively, postoperatively on day 1 and weekly until follow-up at the orthopedic clinic 8 weeks after surgery. ROM recovery patterns were compared between patients with sufficient (≥ 90°) or insufficient (< 90°) knee flexion 8 weeks after TKA. RESULTS: Knee flexion recovered from a median of 80° in the first postoperative week to 110° 8 weeks after surgery and knee extension from a mean of - 10.7° to - 3.2°. Recovery was nonlinear, with greatest improvements in the first 4 weeks for knee flexion. In contrast to patients with sufficient knee flexion 8 weeks postoperatively, the insufficient group (n = 8, 5.8%) had poor knee flexion on the first postoperative day and from week 4 to week 8 almost no improvement or even worsening of knee flexion. CONCLUSIONS: Both knee flexion and extension recover in a nonlinear manner after TKA surgery. Poor postoperative knee function can be detected early, using ROM data from the first postoperative day up to the fourth week.

Correction to: No difference in mid-term survival and clinical outcome between patient-specific and conventional instrumented total knee arthroplasty: a randomized controlled trial.

In the original article, one of the co-author's (W. van der Weegen) middle name has been missed in the publication of the article. The correct complete name should be W. van der Weegen.

No difference in mid-term survival and clinical outcome between patient-specific and conventional instrumented total knee arthroplasty: a randomized controlled trial.

PURPOSE: The purpose of this multicentre prospective randomized controlled trial was to compare the survival rate and clinical outcome in total knee arthroplasty (TKA) after MRI-based patient-specific instruments (PSI) and conventional instruments 5 years after initial surgery. METHODS: At a mean follow-up of 5.1 years (0.4), 163 patients (90.6%) with a mean age of 71.8 years (8.7) were analysed. A survival analysis with revision of the TKA as endpoint was performed. The Knee Society Score (KSS), evaluations on plain radiographs and patient-reported outcome measures (PROMs) were obtained preoperatively and at each FU. RESULTS: At final follow-up, one TKA in the PSI- (1.2%) and 3 TKAs in the conventional group (3.8%) had undergone revision surgery (n.s.). No radiological abnormalities were noted at any time point. Postoperatively, the KSS and PROMs significantly improved within each group compared with the preoperative values. There were no clinically relevant differences for the KSS [PSI: 77.4, 9.8 (95% CI 75.0-79.7) vs. conventional: 77.3 10.5 (95% CI 74.9-79.8)] and the PROMs between both groups (n.s.) at 5 years follow-up. CONCLUSION: There is still a lack of reliable data on the survival of TKA and clinical evidence, when using PSI for TKA. Longer follow-up studies are, therefore, needed. LEVEL OF EVIDENCE: I.

Manipulation under anesthesia following total knee arthroplasty: a comprehensive review of literature.

INTRODUCTION: The etiology of the stiff knee after total knee arthroplasty (TKA) is largely unknown, although excessive scar tissue due to arthrofibrosis is an important reason for a limited range of motion (ROM) after this procedure. Persistent limited ROM after TKA results in poor patient-reported outcomes and is increasingly becoming a more prominent reason for TKA revision surgery. METHODS: A narrative review of current literature on manipulation under anesthesia (MUA) after TKA analyzing etiology and risk factors for stiffness after TKA, effectiveness of MUA and what is known about rehabilitation after MUA. RESULTS: Literature describes numerous risk factors for insufficient knee ROM after TKA, but a comprehensive valid risk model is lacking. MUA is an effective treatment option with evidence suggesting better outcomes if performed within the first 3 months after TKA. The wide variety in both the indication and timing for MUA, and the lack of scientific evidence on how to rehabilitate patients after MUA, complicates the interpretation of available literature. This is even more so the case on the reporting of one versus two or more MUAs after TKA. CONCLUSION: Future comparative trials, preferably with a randomized study design, should be conducted to elude more clear indications for MUA, to give clinical guidance on correct timing for MUA and on how to rehabilitate patients afterward.

No difference in clinical outcome between patient-matched positioning guides and conventional instrumented total knee arthroplasty two years post-operatively: a multicentre, double-blind, randomised controlled trial.

AIMS: We wished to compare the clinical outcome, as assessed by questionnaires and the rate of complications, in total knee arthroplasty (TKA) undertaken with patient-matched positioning guides (PMPGs) or conventional instruments. PATIENTS AND METHODS: A total of 180 patients (74 men, 106 women; mean age 67 years) were included in a multicentre, adequately powered, double-blind, randomised controlled trial. The mean follow-up was 44 months (24 to 57). RESULTS: There were no significant or clinically relevant differences between the two groups for all outcome measures (Knee Society Score, p = 0.807; Oxford Knee Score, p = 0.304; Western Ontario and McMaster osteoarthritis index, p = 0.753; visual analogue scale for pain, p = 0.227; EuroQol-5D-3L index score, p = 0.610; EuroQol-5D-3L VAS health, p = 0.968.) There was no difference in the rate of complications (p = 0.291). CONCLUSION: PMPGs are already in relatively common use and their short-term clinical results are equal to conventional instrumented TKA. Cite this article: Bone Joint J 2016;98-B:939-44.

The rate of dislocation is not increased when minimal precautions are used after total hip arthroplasty using the posterolateral approach: a prospective, comparative safety study.

AIMS: In order to prevent dislocation of the hip after total hip arthroplasty (THA), patients have to adhere to precautions in the early post-operative period. The hypothesis of this study was that a protocol with minimal precautions after primary THA using the posterolateral approach would not increase the short-term (less than three months) risk of dislocation. PATIENTS AND METHODS: We prospectively monitored a group of unselected patients undergoing primary THA managed with standard precautions (n = 109, median age 68.9 years; interquartile range (IQR) 61.2 to 77.3) and a group who were managed with fewer precautions (n = 108, median age 67.2 years; IQR 59.8 to 73.2). There were no significant differences between the groups in relation to predisposing risk factors. The diameter of the femoral head ranged from 28 mm to 36 mm; meticulous soft-tissue repair was undertaken in all patients. The medical records were reviewed and all patients were contacted three months post-operatively to confirm whether they had experienced a dislocation. RESULTS: There were no dislocations in the less restricted group and one in the more restricted group (p = 0.32). CONCLUSION: For experienced surgeons using the posterolateral approach at THA and femoral heads of diameter ≥ 28 mm, it appears safe to manage patients in the immediate post-operative period with minimal precautions to protect against dislocation. Larger studies with adequate statistical power are needed to verify this conclusion. TAKE HOME MESSAGE: Experienced orthopaedic surgeons using the posterolateral approach for THA should not fear an increased dislocation rate if they manage their patients with a minimal precautions protocol. Cite this article: Bone Joint J 2016;98-B:589-94.

The Effectiveness of Debridement, Antibiotics and Irrigation for Periprosthetic Joint Infections after Primary Hip and Knee Arthroplasty. A 15 Years Retrospective Study in Two Community Hospitals in the Netherlands.

The aim of our study was to evaluate the effectiveness of debridement, antibiotics, irrigation and retention (DAIR) in patients who developed a periprosthetic joint infection (PJI) after primary hip or knee arthroplasty in two community hospitals in the Netherlands. We retrospectively collected data in two hospitals in the Netherlands on all episodes of PJI after primary hip (THA) and knee arthroplasty (TKA) from 1998-2012. In 109 of 8234 THA (1.32%) and 65 of 5752 TKA (1.13%) a PJI developed. DAIR was used as treatment in 84 patients after THA (77.1%) and 56 patients after TKA (86.2%). 34 Patients only received antibiotics or were immediately revised. After 1 year follow-up, prosthesis retention was achieved in 81 THA patients (74.3%) and 48 TKA patients (73.8%). Acute infections showed a better survival compared to late infections (84.0% vs 46.6% respectively; p<0.01). Furthermore, a young age was associated with an increased revision risk (p<0.01). In conclusion, debridement, antibiotics and irrigation in acute PJI may lead to retention of the prosthesis in a majority of cases. Large patient cohort studies can provide data on PJI outcome, complementing National Registries which have limited detail.

Comparison of different pseudotumor grading systems in a single cohort of metal-on-metal hip arthroplasty patients.

OBJECTIVE: Follow-up of pseudotumors observed with metal-artefact reducing sequence (MARS)-magnetic resonance imaging (MRI) following metal-on-metal total hip arthroplasty (MoMTHA) depends on how severe these pseudotumors are graded. Several pseudotumor grading systems for MARS-MRI have emerged but little is known of their validity. We studied the intra- and interobserver reliability of three different pseudotumor grading systems in a single cohort of MoMTHA. PATIENTS AND METHODS: Two experienced musculoskeletal radiologists independently used three different pseudotumor grading systems for classifying MARS-MRI results of the same cohort of 42 MoMTHA patients (49 hips, mean follow-up 5.2 years). Intraobserver and interobserver reliability for each grading system was measured using Cohen's kappa (κ). Variance in pseudotumor severity grading between systems was analyzed. RESULTS: Intraobserver reliability on grading pseudotumor severity with the Anderson, Matthies, and Hauptfleisch grading system scored 0.47, 0.10, and 0.35 (observer 1), and 0.75, 0.38, and 0.42 (observer 2), respectively. Interobserver reliability scores for pseudotumor severity were 0.58, 0.23, and 0.34, respectively. CONCLUSIONS: Intraobserver reliability for grading pseudotumor severity on MARS-MRI ranged from poor to good, dependent on observer and grading system used. Interobserver reliability scored best with the Anderson system. A more succinct pseudotumor severity grading system is needed for clinical use.

Asymptomatic pseudotumours after metal-on-metal hip resurfacing show little change within one year.

The aim of this study was to establish the natural course of unrevised asymptomatic pseudotumours after metal-on-metal (MoM) hip resurfacing during a six- to 12-month follow-up period. We used repeated metal artefact reduction sequence (MARS)-magnetic resonance imaging (MRI), serum metal ion analysis and clinical examination to study 14 unrevised hips (mean patient age 52.7 years, 46 to 68, 5 female, 7 male) with a pseudotumour and 23 hips (mean patient age 52.8 years, 38 to 69, 7 female, 16 male) without a pseudotumour. The mean post-operative time to the first MARS-MRI scan was 4.3 years (2.2 to 8.3), and mean time between the first and second MARS-MRI scan was eight months (6 to 12). At the second MRI scan, the grade of severity of the pseudotumour had not changed in 35 hips. One new pseudotumour (Anderson C2 score, moderate) was observed, and one pseudotumour was downgraded from C2 (moderate) to C1 (mild). In general, the characteristics of the pseudotumours hardly changed. Repeated MARS-MRI scans within one year in patients with asymptomatic pseudotumours after MoM hip resurfacing showed little or no variation. In 23 patients without pseudotumour, one new asymptomatic pseudotumour was detected. This is the first longitudinal study on the natural history of pseudotumours using MARS-MRI scans in hip resurfacing, and mirrors recent results for 28 mm diameter MoM total hip replacement.

Intra-operative results and radiological outcome of conventional and patient-specific surgery in total knee arthroplasty: a multicentre, randomised controlled trial.

PURPOSE: This prospective, double-blind, randomised controlled trial was designed to address the following research questions: firstly, is there a significant difference in outliers in alignment in the frontal and sagittal plane between PSG TKA and conventional TKA. Secondly, is there a significant difference in operation time, blood loss and length of hospital stay between the two techniques. We hypothesise that there will be fewer outliers with PSG TKA and that operation time, blood loss and length of hospital stay can be significantly reduced with PSG. METHODS: A total of 180 patients were randomised for PSG TKA (group 1) or conventional TKA (group 2) in two centres. Patients were stratified per hospital. Alignment of the mechanical axis of the leg and flexion/extension and varus/valgus of the individual prosthesis components were measured on digital, standing, long-leg and standard lateral radiographs by two independent outcome assessors in both centres. Percentages of outliers (>3°) were determined. We compared blood loss, operation time and length of hospital stay. RESULTS: There was no statistically significant difference in mean mechanical axis or outliers in mechanical axis between groups. No statistically significant difference was found for the alignment of the individual components in the frontal plane nor for the percentages of outliers. There was a statistically significant difference in outliers for the femoral component in the sagittal plane, with a higher percentage of outliers in the group 1 (p = 0.017). No such significant result was found for the tibial component in that plane. All interclass correlation coefficients were good. Blood loss was 100 mL less in group 1 (p < 0.001). Operation time was 5 min shorter in group 1 (p < 0.001). Length of hospital stay was identical with a mean of 3.6 days (p = 0.657). CONCLUSIONS: The results in terms of obtaining a neutral mechanical axis and a correct position of the prosthesis components did not differ between groups. A small reduction in operation time and blood loss was found with the PSG system. Future research should especially focus on cost-effectiveness analysis and functional outcome of PSG TKA. LEVEL OF EVIDENCE: I.

Survival of metal-on-metal hip resurfacing arthroplasty: a systematic review of the literature.

We systematically reviewed the peer-reviewed literature to relate the survival of hybrid metal-on-metal hip resurfacing arthroplasty devices to a National Institute of Clinical Excellence (NICE) benchmark for choosing a primary total hip replacement, which is a survival rate of 90% at a follow-up of ten years. A total of 29 articles (10 621 resurfaced hips) met the inclusion criteria. The mean follow-up ranged from 0.6 to 10.5 years and the survival of the implant ranged from 84% to 100%. Of the 10 621 hips, 370 were revised (3.5%), with aseptic loosening as the most frequent mode of failure. None of the hip resurfacing arthroplasty implants used to date met the full ten-year NICE benchmark of survival. A total of 13 studies showed satisfactory survival compared with the three-year NICE benchmark.