Letter to the Editor on “Indications for MARS-MRI in Patients Treated With Articular Surface Replacement XL Total Hip Arthroplasty”

[no abstract

Metal-on-metal hip arthroplasty: indications for continued use in light of adverse reaction to metal debris

Adverse reaction to metal debris (ARMD) represents a recently recognised mode of failure of metal-on-metal (MoM) hip resurfacings (HRs) and total hip replacements (THRs). ARMD often requires revision surgery which can have poor outcomes, therefore questioning the future role of MoM hip bearings. The 14-year survival of 447 HRs implanted by a designing surgeon was 94.1% (95% CI 84.9%-97.3%) with the best outcomes in males with primary osteoarthritis. The 8-year survival of 578 MoM THRs was 88.9% (95% CI 78.5%-93.4%) with 44% (17 of 39) of revisions performed for ARMD. A systematic review identified six studies reporting short-term outcomes following 216 ARMD revisions with variable complication (4%-68%) and re-revision (3%-38%) rates. Analysis of outcomes following 64 ARMD revisions demonstrated comparable complication (20.3%) and re-revision (12.5%) rates at a mean 4.5 year follow-up. The 5-year survival following ARMD revision was 87.9% (95% CI 78.9%-98.0%) with revision to another MoM bearing having significantly higher re-revision rates (p=0.046). Male patients with primary osteoarthritis may undergo HR in the future, however designing surgeons may also consider females for HR. There is no future role for MoM THR. Limited evidence exists regarding outcomes following ARMD revision, though exchange to a non-MoM bearing surface is advised

Does venous thromboembolism prophylaxis affect the risk of venous thromboembolism and adverse events following primary hip and knee replacement?:A retrospective cohort study

BACKGROUND: The optimum chemical venous thromboembolism (VTE) prophylactic agents following total hip and knee replacement (THR and TKR) remain unknown. NICE recommends multiple agents, including direct oral anticoagulants (DOACs), low-molecular weight heparin (LMWH), and aspirin. We assessed whether VTE prophylaxis affected the risk of VTE and adverse events following primary THR and TKR. MATERIALS AND METHODS: We reviewed 982 elective primary THRs (59%) and TKRs (41%) at a large tertiary centre during 2018. The primary outcome was any VTE (DVT and/or PE) within 90-days. Secondary outcomes were adverse events within 90-days (major bleeding and wound complications). The association between VTE prophylaxis and outcomes was assessed. RESULTS: The overall prevalence of VTE and adverse events were 2.7% (n = 27) and 15.2% (n = 136) respectively. The most common agents used were DOAC ± LMWH (50.7%, n = 498), followed by aspirin ± LMWH (35.5%, n = 349) and LMWH alone (4.7%, n = 46). The risk of VTE (aspirin ± LMWH = 3.7%, DOAC = 2.0%, LMWH = 2.2%) was not significantly different between agents (p = 0.294). The risk of any adverse event was significantly higher (p < 0.001) with aspirin ± LMWH (16.1%; n = 56) and LMWH (28.3%; n = 13) compared with DOACs ± LMWH (7.0%; n = 35) in TKRs only, there was no differences between agents for adverse events in THRs (p = 0.644). CONCLUSIONS: Choice of thromboprophylaxis did not influence the risk of VTE following primary THR and TKR. DOACs (+/− LMWH) were associated with the lowest risk of adverse events. Large multicentre trials are still needed to assess the efficacy and safety of these agents following THR and TKR

Does regional anaesthesia reduce complications following total hip and knee replacement compared with general anaesthesia?:An analysis from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

Background Regional anesthesia is increasingly used in enhanced recovery programs following total hip replacement (THR) and total knee replacement (TKR). However, debate remains about its potential benefit over general anesthesia given that complications following surgery are rare. We assessed the risk of complications in THR and TKR patients receiving regional anesthesia compared with general anesthesia using the world’s largest joint replacement registry. Methods We studied the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man linked to English hospital inpatient episodes for 779,491 patients undergoing THR and TKR. Patients received either regional anesthesia (n = 544,620, 70%) or general anesthesia (n = 234,871, 30%). Outcomes assessed at 90 days included length of stay, readmissions, and complications. Regression models were adjusted for patient and surgical factors to determine the effect of anesthesia on outcomes. Results Length of stay was reduced with regional anesthesia compared with general anesthesia (THR = −0.49 days, 95% confidence interval [CI] = −0.51 to −0.47 days, P < .001; TKR = −0.47 days, CI = −0.49 to −0.45 days, P < .001). Regional anesthesia also had a reduced risk of readmission (THR odds ratio [OR] = 0.93, CI = 0.90-0.96; TKA OR = 0.91, CI = 0.89-0.93), any complication (THR OR = 0.88, CI = 0.85-0.91; TKA OR = 0.90, CI = 0.87-0.93), urinary tract infection (THR OR = 0.85, CI = 0.77-0.94; TKR OR = 0.87, CI = 0.79-0.96), and surgical site infection (THR OR = 0.87, CI = 0.80-0.95; TKR OR = 0.84, CI = 0.78-0.89). Anesthesia type did not affect the risk of revision surgery or mortality. Conclusion Regional anesthesia was associated with reduced length of stay, readmissions, and complications following THR and TKR when compared with general anesthesia. We recommend regional anesthesia should be considered the reference standard for patients undergoing THR and TKR

The effect of surgeon caseload on the relative revision rate of cemented and cementless Unicompartmental Knee Replacements:An analysis from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

Background: Unicompartmental knee replacement (UKR) offers substantial benefits compared with total knee replacement (TKR) but is associated with higher revision rates. Data from registries suggest that revision rates for cementless UKR implants are lower than those for cemented implants. It is not known how much of this difference is due to the implant or to other factors, such as a greater proportion of high-volume surgeons using cementless implants. We aimed to determine the effect of surgeon caseload on the revision rate of matched cemented and cementless UKRs. Methods: From a group of 40,522 Oxford (Zimmer Biomet) UKR implants (30,814 cemented, 9,708 cementless) recorded in the National Joint Registry, 14,814 (7,407 cemented, 7,407 cementless) were propensity-score matched. Surgeons were categorized into 3 groups: low volume ( Results: The 10-year survival rates for unmatched cementless and cemented UKR implants were 93.3% (95% confidence interval [CI] = 89.8% to 95.7%) and 89.1% (95% CI = 88.6% to 89.6%), respectively, with the difference being significant (hazard ratio [HR] = 0.59; p Conclusions: Cementless fixation decreased the revision rate by about a quarter, whatever the surgeon caseload. Caseload had a profound effect on implant survival. Low-volume surgeons had a high revision rate with cemented or cementless fixation and therefore should consider either stopping or doing more UKR procedures. High-volume surgeons performing cementless UKR demonstrated a 10-year survival rate of 97.5%, which was similar to that reported in registries for the best-performing TKRs. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.</p

A matched comparison of revision rates of cemented Oxford Unicompartmental Knee Replacements with Single and Twin Peg femoral components, based on data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

Background and purpose — Registries report high revision rates after unicompartmental knee replacement (UKR) due, in part, to aseptic loosing. In an attempt to improve Oxford UKR femoral component fixation a new design was introduced with a Twin rather than a Single peg. We used the National Joint Registry (NJR) to compare the 5-year outcomes of the Single and Twin Peg cemented Oxford UKRs. Patients and methods — We performed a retrospective observational study using NJR data on propensity score matched Single and Twin Peg UKRs (matched for patient, implant and surgical factors). Data on 2,834 Single Peg and 2,834 Twin Peg were analyzed. Cumulative implant survival was calculated using the Kaplan–Meier method and comparisons between groups performed using Cox regression models. Results — In the matched cohort, the mean follow up for both Single and Twin Peg UKRs was 3.3 (SD 2) and 3.4 years (SD 2) respectively. The 5-year cumulative implant survival rates for Single Peg and Twin Peg were 94.8% (95% CI 93.6–95.8) and 96.2% (CI 95.1–97.1) respectively. Implant revision rates were statistically significantly lower in the Twin Peg (hazard ratio [HR)] = 0.74; p = 0.04). The revision rate for femoral component aseptic loosening decreased significantly (p = 0.03) from 0.4% (n = 11) with the Single Peg to 0.1% (n = 3) with the Twin Peg. The revision rate for pain decreased significantly (p = 0.01) from 0.8% (n = 23) with the Single Peg to 0.3% (n = 9) with the Twin Peg. No other reasons for revision had significant differences in revision rates. Interpretation — The revision rate for the cemented Twin Peg Oxford UKR was 26% less than the Single Peg Oxford UKR. This was mainly because the revision rates for femoral loosening and pain more than halved. This suggests that the Twin Peg component should be used in preference to the Single Peg design.</p

New surgical instrumentation reduces the revision rate of Unicompartmental Knee Replacement:A propensity score matched comparison of 15,906 knees from the National Joint Registry

Background Unicompartmental knee replacement (UKR) offers advantages over total knee replacement but has higher revision rates. New instrumentation known as Microplasty was introduced to address this. The aim was to compare the revision rates of UKRs implanted with Microplasty and traditional instrumentation (Non-Microplasty). Methods National Joint Registry (NJR) data was used to propensity score match 15,906 UKRs (7953 Microplasty and 7953 Non-Microplasty) for important patient, implant and surgical factors. Implant survival rates were determined using the Kaplan–Meier method and compared using Cox regression models in a multilevel model. Results The five-year implant survival for Microplasty and Non-Microplasty UKRs were 96.7% (95% CI: 96.0%–97.2%) and 94.5% (CI: 93.8–95.1%), respectively. The revision rate for Microplasty UKR was significantly lower than that of Non-Microplasty UKRs (hazard ratio [HR] = 0.77, p = 0.008). Compared with Non-Microplasty UKRs, the revision rate of Microplasty UKRs implanted during the year after the introduction of Microplasty was lower, but the difference was not significant (HR: 0.86, CI: 0.67–1.10, p = 0.23), whereas for those implanted more than a year after introduction, the difference was significant (HR: 0.69, CI: 0.54–0.89, p = 0.004). Conclusion The use of Microplasty instrumentation has resulted in an improved five-year UKR survival. Microplasty UKR implanted during the first year after introduction had a small, non-significant decrease in revision rate. As the revision rate did not increase, this suggests that there is no adverse learning curve effect. Microplasty UKRs implanted after this transition period had a revision rate 31% lower than the Non-Microplasty group. Level of evidence II.</p