Early Recovery Following Total and Unicompartmental Knee Arthroplasty Assessed Using Novel Patient-Reported Measures.

BACKGROUND: The early postoperative recovery period following unicompartmental (UKA) and total knee arthroplasty (TKA) is an important area for research with increasingly sensitive metrics and new technologies. This study uses 2 recently developed patient-reported scores to compare the recovery following UKA and TKA. METHODS: Two consecutive cohorts of 37 UKAs and 33 TKAs completed the Oxford Arthroplasty Early Recovery Score (OARS) and the Oxford Arthroplasty Early Change Score (OACS) on days 1, 2, 3, 7, 14, and week 6. The Short Form-36 version 2 was also completed on weeks 1, 2, and 6. Improvements within cohorts and comparisons between cohorts were assessed. RESULTS: For both UKA and TKA the speed of recovery was rapid early on and then progressively decreased. At all time points, the UKA cohort reported similar or significantly better scores than the TKA cohort. The overall OARS (P < .001) showed that UKA recovered, shown as improvement on the OARS, 2-3 times faster than TKA. OARS subscales demonstrated that UKA had better Function/Mobility (P = .003) particularly early in the recovery, and better Nausea/Feeling Unwell (P < .001) and Fatigue/Sleep (P = .009) later in the recovery. UKA also had less pain at 2 weeks (P = .03). There was no significant difference between UKA and TKA OACS. UKA had significantly better scores in 3 of the 8 Short Form-36 domains, with the largest difference being in Role-Emotional (P = .003). CONCLUSION: The OARS is useful for the assessment of postoperative recovery. This study provides direct evidence that recovery following UKA is better and 2-3 times faster than following TKA. All differences may be explained by the less invasive nature of UKA.

Most unicompartmental knee replacement revisions could be avoided: a radiographic evaluation of revised Oxford knees in the National Joint Registry.

PURPOSE: The purpose of this study was to understand why the revision rate of unicompartmental knee replacement (UKR) in the National Joint Registry (NJR) is so high. Using radiographs, the appropriateness of patient selection for primary surgery, surgical technique, and indications for revision were determined. In addition, the alignment of the radiographs was assessed. METHODS: Oxford UKR registered with the NJR between 2006 and 2010 and subsequently revised were identified by the NJR. A blinded review was undertaken of pre-primary, post-primary, and pre-revision anteroposterior and lateral radiographs of a sample of 107 cases from multiple centres. RESULTS: The recommended indications were satisfied in 70%, with 29% not demonstrating bone-on-bone arthritis. Major technical errors, likely leading to revision, were seen in 6%. Pre-revision radiographs were malaligned and, therefore, difficult to interpret in 53%. No reason for revision was seen in 67%. Reasons for revision included lateral compartment arthritis (10%), tibial loosening (7%), bearing dislocation (7%), infection (6%), femoral loosening (3%), and peri-prosthetic fracture (2%, one femoral, one tibial). CONCLUSIONS: Only 20% of the revised UKR were implanted for the recommended indications, using appropriate surgical technique and had a mechanical problem necessitating revision. One-third of primary surgeries were undertaken in patients with early arthritis, which is contraindicated. Two-thirds were presumably revised for unexplained pain, which is not advised as it tends not to help the pain. This study suggests that variable and inappropriate indications for primary and revision surgery are responsible for the high rates of revision seen in registries. LEVEL OF EVIDENCE: III, Therapeutic study.

Do Trabecular Metal Acetabular Components Reduce the Risk of Rerevision After Revision THA Performed for Periprosthetic Joint Infection? A Study Using the NJR Data Set.

BACKGROUND: A single-center study of 144 THAs revised specifically for periprosthetic joint infection (PJI) observed that trabecular metal (TM) acetabular components had a reduced risk of rerevision for subsequent infection compared with non-TM implants. It was suggested that TM was protective against infection after revision and that TM may be useful when revising THAs for PJI. Three registry studies have subsequently assessed the effect of TM on future infection. In the National Joint Registry (NJR) for England and Wales, we earlier reported lower revision rates for infection when TM (versus non-TM) was used in primary THA, but no difference in rerevision rates for infection when TM was used for all-cause revision THAs. The latter findings in all-cause revisions were also confirmed in a study from the Swedish and Australian registries. It is possible that TM only reduces the risk of infection when it is specifically used for PJI revisions (rather than all-causes). However, to date, the registry analyses have not had large enough cohorts of such cases to assess this meaningfully. QUESTIONS/PURPOSES: (1) In revision THAs performed for PJI, are rerevision rates for all-cause acetabular indications lower with TM acetabular components compared with non-TM designs? (2) In revision THAs performed for PJI, are rerevision rates of any component for infection lower with TM acetabular components compared with non-TM designs? METHODS: A retrospective observational study was performed using NJR data from England and Wales, which is the world's largest arthroplasty registry and contains details of over two million joint replacement procedures. The registry achieves high levels of patient consent (92%) and linked procedures (ability to link serial procedures performed on the same patient and hip; 94%). Furthermore, recent validation studies have demonstrated that when revision procedures have been captured within the NJR, the data completion and accuracy were excellent. Of 11,988 revisions performed for all causes, 794 were performed for PJI in which the same cementless acetabular component produced by one manufacturer was used. Acetabular components were either TM (n = 541) or non-TM (n = 253). At baseline the two groups were comparable for sex, age, body mass index, and American Society of Anesthesiologists (ASA) grade. Outcomes after revision THA (rerevision for all-cause acetabular indications and rerevision of any component for infection) were compared between the groups using Fine and Gray regression analysis, which considers the competing mortality risk. Regression models were adjusted for the propensity score, with this score summarizing many of the potential patient and surgical confounding factors (age, sex, ASA grade, surgeon grade, approach, and type of revision procedure performed). RESULTS: There was no difference in 5-year cumulative acetabular component survival rates between TM (96.3%; 95% confidence interval [CI], 94%-98%) and non-TM components (94.4%, 95% CI, 90%-97%; subhazard ratio, 0.78, 95% CI, 0.37-1.65; p = 0.509). There was no difference in 5-year cumulative implant survival rates free from infection between TM (94.8%; 95% CI, 92%-97%) and non-TM components (94.4%, 95% CI, 90%-97%; subhazard ratio, 0.97, 95% CI, 0.48-1.96; p = 0.942). CONCLUSIONS: We found no evidence to support the notion that TM acetabular components used for PJI revisions reduced the subsequent risk of all-cause rerevision or the risk of rerevision for infection compared with non-TM implants from the same manufacturer. We therefore advise caution against recent claims that TM components may protect against infection. LEVEL OF EVIDENCE: Level III, therapeutic study.

No Threshold Exists for Recommending Revision Surgery in Metal-on-Metal Hip Arthroplasty Patients With Adverse Reactions to Metal Debris: A Retrospective Cohort Study of 346 Revisions.

BACKGROUND: Surgeons currently have difficulty when managing metal-on-metal hip arthroplasty (MoMHA) patients with adverse reactions to metal debris (ARMD). This stems from a lack of evidence, which is emphasized by the variability in the recommendations proposed by different worldwide regulatory authorities for considering MoMHA revision surgery. We investigated predictors of poor outcomes following MoMHA revision surgery performed for ARMD to help inform the revision threshold and type of reconstruction. METHODS: We retrospectively studied 346 MoMHA revisions for ARMD performed at 2 European centers. Preoperative (metal ions/imaging) and intraoperative (findings, components removed/implanted) factors were used to predict poor outcomes. Poor outcomes were postoperative complications (including re-revision), 90-day mortality, and poor Oxford Hip Score. RESULTS: Poor outcomes occurred in 38.5%. Shorter time (under 4 years) to revision surgery was the only preoperative predictor of poor outcomes (odds ratio [OR] = 2.12, confidence interval [CI] = 1.00-4.46). Prerevision metal ions and imaging did not influence outcomes. Single-component revisions (vs all-component revisions) increased the risk of poor outcomes (OR = 2.99, CI = 1.50-5.97). Intraoperative modifiable factors reducing the risk of poor outcomes included the posterior approach (OR = 0.22, CI = 0.10-0.49), revision head sizes ≥36 mm (vs <36 mm: OR = 0.37, CI = 0.18-0.77), ceramic-on-polyethylene revision bearings (OR vs ceramic-on-ceramic = 0.30, CI = 0.14-0.66), and metal-on-polyethylene revision bearings (OR vs ceramic-on-ceramic = 0.37, CI = 0.17-0.83). CONCLUSION: No threshold exists for recommending revision in MoMHA patients with ARMD. However postrevision outcomes were surgeon modifiable. Optimal outcomes may be achieved if surgeons use the posterior approach, revise all MoMHA components, and use ≥36 mm ceramic-on-polyethylene or metal-on-polyethylene articulations.

Randomized Prospective Comparative Study of Adductor Canal Block vs Periarticular Infiltration on Early Functional Outcome After Unilateral Total Knee Arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is associated with significant postoperative pain. Effective pain relief is essential for early postoperative rehabilitation. Periarticular infiltration (PAI) and adductor canal block (ACB) have become popular modes of pain management after TKA. Our aim is to compare their efficacy and impact on early functional outcome in patients undergoing TKA. METHODS: A single-blinded randomized controlled trial, 100 patients undergoing unilateral primary TKA for symptomatic osteoarthritis were allocated to either of the 2 groups (50 in each arm): postoperative ultrasound-guided single shot of ACB (group A) or intraoperative PAI (group B). All patients underwent TKA without patella resurfacing under spinal anesthesia. Preoperative workup, surgical technique, and postoperative management were standardized for all the patients. Patients were assessed for pain using visual analogue scale at 6, 12, and 24 hours after surgery; hemoglobin level preoperatively and postoperatively on day 1 to calculate blood loss; hospital stay; tourniquet time; operative time; and postoperative complications by an independent observer blinded to the group allocation. RESULTS: Patients were matched for age, gender, American Society of Anesthesiologists grade, and deformity. Visual analogue scale (scale 0-10) between PAI and ACB at 6, 12, and 24 hours were significantly different (P < .05) with higher scores seen in patients with ACB at all time points. Tourniquet time and operative time were significantly longer in the PAI than ACB. No significant difference in hospital stay was observed. No complications occurred during the study. CONCLUSION: PAI achieves better pain control as compared to ACB in patients undergoing unilateral TKA.

Risk Factors for Intraoperative Periprosthetic Femoral Fractures During Primary Total Hip Arthroplasty. An Analysis From the National Joint Registry for England and Wales and the Isle of Man.

BACKGROUND: The aim of this study is to estimate risk factors for intraoperative periprosthetic femoral fractures (IOPFF) and each anatomic subtype (calcar crack, trochanteric fracture, femoral shaft fracture) during primary total hip arthroplasty. METHODS: This retrospective cohort study included 793,823 primary total hip arthroplasties between 2004 and 2016. Multivariable regression modeling was used to estimate relative risk of patient, surgical, and implant factors for any IOPFF and for all anatomic subtypes of IOPFF. Clinically important interactions were assessed using multivariable regression. RESULTS: Patient factors significantly increasing the risk of fracture were female gender, American Society of Anesthesiologists grade 3 to 5, and preoperative diagnosis including avascular necrosis of the hip, previous trauma, inflammatory disease, pediatric disease, and previous infection. Overall risk of IOPFF associated with age was greatest in patients below 50 years and above 80 years. Risk of any fracture reduced with computer-guided surgery and in non-National Health Service hospitals. Nonposterior approaches increased the risk of shaft and trochanteric fracture only. Cementless implants significantly increased the risk of only calcar cracks and shaft fractures and not trochanteric fractures. CONCLUSION: Fracture risk increases in patients younger than 50 and older than 80 years, females, American Society of Anesthesiologists grade 3 to 5, and indications other than primary osteoarthritis. Large cumulative reduction in IOPFF risk may occur with use of cemented implants, posterior approach, and computer-guided surgery. LEVEL OF EVIDENCE: Level 3b (cohort study).

The effect of smoking on outcomes following primary total hip and knee arthroplasty: a population-based cohort study of 117,024 patients.

Background and purpose - Smoking is a modifiable risk factor that may adversely affect postoperative outcomes. Healthcare providers are increasingly denying smokers access to total hip and knee arthroplasty (THA and TKA) until they stop smoking. Evidence supporting this is unclear. We assessed the effect of smoking on outcomes following arthroplasty.Patients and methods - We identified THAs and TKAs from the Clinical Practice Research Datalink, which were linked with datasets from Hospital Episode Statistics and the Office for National Statistics to identify outcomes. The effect of smoking on postoperative outcomes (complications, medications, revision, mortality, patient-reported outcome measures [PROMs]) was assessed using adjusted regression models.Results - We studied 60,812 THAs and 56,212 TKAs (11% smokers, 33% ex-smokers, 57% non-smokers). Following THA, smokers had an increased risk of lower respiratory tract infection (LRTI) and myocardial infarction compared with non-smokers and ex-smokers. Following TKA, smokers had an increased risk of LRTI compared with non-smokers. Compared with non-smokers (THA relative risk ratio [RRR] = 0.65; 95% CI = 0.61-0.69; TKA RRR = 0.82; CI = 0.78-0.86) and ex-smokers (THR RRR = 0.90; CI = 0.84-0.95), smokers had increased opioid usage 1-year postoperatively. Similar patterns were observed for weak opioids, paracetamol, and gabapentinoids. 1-year mortality rates were higher in smokers compared with non-smokers (THA hazard ratio [HR] = 0.37, CI = 0.29-0.49; TKA HR = 0.52, CI = 0.34-0.81) and ex-smokers (THA HR = 0.53, CI = 0.40-0.70). Long-term revision rates were not increased in smokers. Smokers had improvement in PROMs compared with preoperatively, with no clinically important difference in postoperative PROMs between smokers, non-smokers, and ex-smokers.Interpretation - Smoking is associated with more medical complications, higher analgesia usage, and increased mortality following arthroplasty. Most adverse outcomes were reduced in ex-smokers, therefore smoking cessation should be encouraged before arthroplasty.

Has the threshold for revision surgery for adverse reactions to metal debris changed in metal-on-metal hip arthroplasty patients? A cohort study of 239 patients using an adapted risk-stratification algorithm.

Background and purpose - A risk-stratification algorithm for metal-on-metal hip arthroplasty (MoMHA) patients was devised by US experts to help clinicians make management decisions. However, the proposed algorithm did not cover all potential patient or surgical abnormalities. Therefore we adapted the US risk-stratification algorithm in MoMHA patients revised for adverse reactions to metal debris (ARMD) to determine the variability in the revision threshold, and also whether high-risk patients had inferior outcomes following revision.Patients and methods - We analysed 239 MoMHA revisions for ARMD between 2001 and 2016 from 2 centres with pre-revision blood metal ions and imaging. Patients were stratified (low risk, moderate risk, high risk) using pre-revision factors (implant, radiographic, blood metal ions, cross-sectional imaging) by adapting a published algorithm. The risk categories for each factor were assessed against revision year, revision centre, and post-revision outcomes (re-revision surgery, and any poor outcome).Results - Compared with hips revised before 2012, hips revised from 2012 onwards included more high-risk implants (44% vs. 17% pre-2012), high-risk radiographic features (85% vs. 69% pre-2012), and low-risk metal ions (41% vs. 19% pre-2012). 1 centre more frequently revised patients with high-risk implants (48% vs. 14%) and low-risk blood metal ions (45% vs. 15%) compared with the other. All these comparisons were statistically significant (p < 0.05). With the limited sample size available, implant, radiographic, blood metal ion, and cross-sectional imaging risk groups did not statistically significantly affect the rates of re-revision surgery or frequency of poor outcomes post-revision.Interpretation - When applying the adapted risk-stratification algorithm the threshold for ARMD revision changed over time, presumably due to increasing evidence, patient surveillance, and investigation since 2012. Lower blood metal ion thresholds were used from 2012 for ARMD revisions; however, there was evidence that centres attached different importance to metal ions when managing patients. High-risk patients did not have inferior outcomes following ARMD revision.

Health Care Professionals' Perceptions of the Arthroplasty Patient Experience: Planning Phase in the Development of a Patient-Reported Outcome Measure.

PURPOSE: The aim of this study was to explore health care professionals' perceptions and perspectives of surgery and early recovery for patients undergoing lower limb arthroplasty. DESIGN: Thematic analysis with semi-structured qualitative interviews. METHODS: Following ethical approval, interviews were performed with recovery room nurses (n=3), ward nurses (n=2), surgeons (n=5), anesthesiologists (n=5), physiotherapists (n=5), and occupational therapists (n=2). Data were analyzed using an in-depth narrative thematic analysis method. NVivo qualitative data analysis software was used. FINDINGS: Three main themes evolved from the interviews: immediate patient recovery issues, discharge criteria, and priorities during hospitalization from health care providers' perspectives. CONCLUSIONS: The early postoperative recovery period can be a challenging time for health care providers and patients alike. However, identifying key areas of importance can provide insight and guide focus in clinical practice, thus improving patient recovery.

Outcomes After Metal-on-metal Hip Revision Surgery Depend on the Reason for Failure: A Propensity Score-matched Study.

BACKGROUND: Metal-on-metal hip replacement (MoMHR) revision surgery for adverse reactions to metal debris (ARMD) has been associated with an increased risk of early complications and reoperation and inferior patient-reported outcome scores compared with non-ARMD revisions. As a result, early revision specifically for ARMD with adoption of a lower surgical threshold has been widely recommended with the goal of improving the subsequent prognosis after ARMD revisions. However, no large cohorts have compared the risk of complications and reoperation after MoMHR revision surgery for ARMD (an unanticipated revision indication) with those after non-ARMD revisions (which represent conventional modes of arthroplasty revision). QUESTIONS/PURPOSES: (1) Does the risk of intraoperative complications differ between MoMHRs revised for ARMD compared with non-ARMD indications? (2) Do mortality rates differ after MoMHRs revised for ARMD compared with non-ARMD indications? (3) Do rerevision rates differ after MoMHRs revised for ARMD compared with non-ARMD indications? (4) How do implant survival rates differ after MoMHR revision when performed for specific non-ARMD indications compared with ARMD? METHODS: This retrospective observational study involved all patients undergoing MoMHR from the National Joint Registry (NJR) for England and Wales subsequently revised for any indication between 2008 and 2014. The NJR achieves high levels of patient consent (93%) and linked procedures (ability to link serial procedures performed on the same patient and hip; 95%). Furthermore, recent validation studies have demonstrated that when revision procedures have been captured within the NJR, the data completion and accuracy were excellent. Revisions for ARMD and non-ARMD indications were matched one to one for multiple potential confounding factors using propensity scores. The propensity score summarizes the many patient and surgical factors that were used in the matching process (including sex, age, type of primary arthroplasty, time to revision surgery, and details about the revision procedure performed such as the approach, specific components revised, femoral head size, bearing surface, and use of bone graft) using one single score for each revised hip. The patient and surgical factors within the ARMD and non-ARMD groups subsequently became much more balanced once the groups had been matched based on the propensity scores. The matched cohort included 2576 MoMHR revisions with each study group including 1288 revisions (mean followup of 3 years for both groups; range, 1-7 years). Intraoperative complications, mortality, and rerevision surgery were compared between matched groups using univariable regression analyses. Implant survival rates in the non-ARMD group were calculated for each specific revision indication with each individual non-ARMD indication subsequently compared with the implant survival rate in the ARMD group using Cox regression analyses. RESULTS: There was no difference between the ARMD and non-ARMD MoMHR revisions in terms of intraoperative complications (odds ratio, 0.97; 95% confidence interval [CI], 0.59-1.59; p = 0.900). Mortality rates were lower after ARMD revision compared with non-ARMD revision (hazard ratio [HR], 0.43; CI, 0.21-0.87; p = 0.019); however, there was no difference when revisions performed for infection were excluded from the non-ARMD indication group (HR, 0.69; CI, 0.35-1.37; p = 0.287). Rerevision rates were lower after ARMD revision compared with non-ARMD revision (HR, 0.52; CI, 0.36-0.75; p < 0.001); this difference persisted even after removing revisions performed for infection (HR, 0.59; CI, 0.40-0.89; p = 0.011). Revisions for infection (5-year survivorship = 81%; CI, 55%-93%; p = 0.003) and dislocation/subluxation (5-year survivorship = 82%; CI, 69%-90%; p < 0.001) had the lowest implant survival rates when compared with revisions for ARMD (5-year survivorship = 94%; CI, 92%-96%). CONCLUSIONS: Contrary to previous observations, MoMHRs revised for ARMD have approximately half the risk of rerevision compared with non-ARMD revisions. We suspect worldwide regulatory authorities have positively influenced rerevision rates after ARMD revision by recommending that surgeons exercise a lower revision threshold and that such revisions are now being performed at an earlier stage. The high risk of rerevision after MoMHR revision for infection and dislocation is concerning. Infected MoMHR revisions were responsible for the increased mortality risk observed after non-ARMD revision, which parallels findings in non-MoMHR revisions for infection. LEVEL OF EVIDENCE: Level III, therapeutic study.

Ten-year patient-reported outcomes following total and minimally invasive unicompartmental knee arthroplasty: a propensity score-matched cohort analysis.

PURPOSE: For patients with medial compartment arthritis who have failed non-operative treatment, either a total knee arthroplasty (TKA) or a unicompartmental knee arthroplasty (UKA) can be undertaken. This analysis considers how the choice between UKA and TKA affects long-term patient-reported outcome measures (PROMs). METHODS: The Knee Arthroplasty Trial (KAT) and a cohort of patients who received a minimally invasive UKA provided data. Propensity score matching was used to identify comparable patients. Oxford Knee Score (OKS), its pain and function components, and the EuroQol 5 Domain (EQ-5D) index, estimated on the basis of OKS responses, were then compared over 10 years following surgery. Mixed-effects regressions for repeated measures were used to estimate the effect of patient characteristics and type of surgery on PROMs. RESULTS: Five-hundred and ninety UKAs were matched to the same number of TKAs. Receiving UKA rather than TKA was found to be associated with better scores for OKS, including both its pain and function components, and EQ-5D, with the differences expected to grow over time. UKA was also associated with an increased likelihood of patients achieving a successful outcome, with an increased chance of attaining minimally clinically important improvements in both OKS and EQ-5D, and an 'excellent' OKS. In addition, for both procedures, patients aged between 60 and 70 and better pre-operative scores were associated with better post-operative outcomes. CONCLUSION: Minimally invasive UKAs performed on patients with the appropriate indications led to better patient-reported pain and function scores than TKAs performed on comparable patients. UKA can lead to better long-term quality of life than TKA and this should be considered alongside risk of revision when choosing between the procedures. LEVEL OF EVIDENCE: II.

The Oxford Medial Unicompartmental Knee Arthroplasty: The South African Experience.

BACKGROUND: The Oxford unicompartmental knee arthroplasty (OUKA) is a successful treatment for endstage, symptomatic anteromedial osteoarthritis. This study reports the results of a cohort of consecutive cemented and cementless medial OUKAs from an independent center and aims to answer the following questions: what is the survival of OUKA in the hands of a nondesigner surgeon? Are there any differences in the survival of cementless and cemented OUKA? Are the failure modes any different with the cementless and cemented OUKA? METHODS: One thousand one hundred twenty consecutive OUKAs were implanted in a single center for the recommended indications. Patients were prospectively identified and followed up. Survival was calculated with revision as the end point. RESULTS: There were 522 cemented and 598 cementless implants. The mean follow-up was 8.3 years for cemented implants (range 0.5-17, standard deviation [SD] 2.9) and 2.7 years (range 0.5-7, SD 1.8) for cementless implants. The Oxford knee score improved from a preoperative mean of 22 (SD 8.1) to 40 (SD 7.9) at the last follow-up (P < .001). There were 59 failures requiring revision surgery, with a 5.3% cumulative revision rate. The most common reason for failure was progression of osteoarthritis in the lateral compartment, occurred in 26 cases (2.3%). The cumulative 10-year survival was 91% (95% confidence interval 87.3-95.2). CONCLUSION: The results of this prospective, consecutive case series from the African continent demonstrated that excellent results are achievable with the OUKA in independent centers if the correct indications and surgical technique are used.

Trabecular Metal Acetabular Components Reduce the Risk of Revision Following Primary Total Hip Arthroplasty: A Propensity Score Matched Study From the National Joint Registry for England and Wales.

BACKGROUND: Trabecular metal (TM)-coated acetabular components are increasingly used in both primary and revision total hip arthroplasty (THA). However, previous studies assessing TM acetabular components have been small single-center cohorts with most lacking a control group. We compared revision rates following primary THA between TM and non-TM-coated acetabular components. METHODS: A retrospective observational study was performed using National Joint Registry data, which included primary THAs with the same cementless acetabular component (either TM or non-TM coated). TM and non-TM implants were matched for multiple potential confounding factors using propensity scores. Outcomes following primary THA (revision for all-cause acetabular indications, aseptic acetabular loosening, and infection) were compared between matched groups using competing risk regression analysis. RESULTS: In 18,200 primary THAs (9100 TM and 9100 non-TM), the overall prevalence of acetabular revision, revision for aseptic acetabular loosening, and septic revision was 1.2%, 0.13%, and 0.59% respectively. Five-year revision rates for all-causes (1.0% vs 1.8%, sub-hazard ratio [SHR] 0.57, 95% confidence interval [CI] 0.43-0.76, P < .001), aseptic acetabular loosening (0.1% vs 0.2%, SHR 0.35, 95% CI 0.14-0.90, P = .029), and infection (0.5% vs 0.9%, SHR 0.51, 95% CI 0.34-0.76, P = .001) were all lower in TM compared with non-TM implants. CONCLUSION: Following primary THA, TM-coated acetabular implants had a reduced risk of both aseptic and septic revision compared with non-TM implants. Although absolute differences in revision risk were small, they may be clinically significant if TM designs were implanted in more complex cases.

Early recovery following lower limb arthroplasty: Qualitative interviews with patients undergoing elective hip and knee replacement surgery. Initial phase in the development of a patient-reported outcome measure.

AIMS AND OBJECTIVES: To explore the patients' perspective of surgery and early recovery when undergoing lower limb (hip or knee) arthroplasty. BACKGROUND: Lower limb arthroplasty is a commonly performed procedure for symptomatic arthritis, which has not responded to conservative medical treatment. Each patient's perspective of the surgical process and early recovery period impacts on their quality of life. DESIGN: Open, semistructured qualitative interviews were used to allow for a deeper understanding of the patient perspective when undergoing a hip or knee arthroplasty. METHODS: Following ethical approval, 30 patients were interviewed between August and November 2016 during the perioperative period while undergoing an elective hip or knee arthroplasty (n = 30). The interviews were performed between the day of surgery and a nine-week postoperative clinic appointment. Data were analysed using an in-depth narrative thematic analysis method. NVivo qualitative data analysis software was used. RESULTS: Seven main themes evolved from the interviews: "improving function and mobility", "pain", "experiences of health care", "support from others", "involvement and understanding of care decisions", "behaviour and coping" and "fatigue and sleeping". CONCLUSIONS: The early postoperative recovery period is of vital importance to all surgical patients. This is no different for the orthopaedic patient. However, identifying key self-reported areas of importance from patients can guide clinical focus for healthcare professionals. RELEVANCE TO CLINICAL PRACTICE: To have specific patient-reported information regarding key areas of importance during the perioperative phase is invaluable when caring for the orthopaedic surgical patient. It gives insight and understanding in to this increasing population group. This study has also served as a starting point in the development of a questionnaire which could be used to assess interventions in the lower limb arthroplasty population. These results will influence both items and content of the questionnaire.

Revision surgery of metal-on-metal hip arthroplasties for adverse reactions to metal debris.

Background and purpose - The initial outcomes following metal-on-metal hip arthroplasty (MoMHA) revision surgery performed for adverse reactions to metal debris (ARMD) were poor. Furthermore, robust thresholds for performing ARMD revision are lacking. This article is the second of 2. The first article considered the various investigative modalities used during MoMHA patient surveillance (Matharu et al. 2018a ). The present article aims to provide a clinical update regarding ARMD revision surgery in MoMHA patients (hip resurfacing and large-diameter MoM total hip arthroplasty), with specific focus on the threshold for performing ARMD revision, the surgical strategy, and the outcomes following revision. Results and interpretation - The outcomes following ARMD revision surgery appear to have improved with time for several reasons, among them the introduction of regular patient surveillance and lowering of the threshold for performing revision. Furthermore, registry data suggest that outcomes following ARMD revision are influenced by modifiable factors (type of revision procedure and bearing surface implanted), meaning surgeons could potentially reduce failure rates. However, additional large multi-center studies are needed to develop robust thresholds for performing ARMD revision surgery, which will guide surgeons' treatment of MoMHA patients. The long-term systemic effects of metal ion exposure in patients with these implants must also be investigated, which will help establish whether there are any systemic reasons to recommend revision of MoMHAs.

What is appropriate surveillance for metal-on-metal hip arthroplasty patients?

The unexpected high revision rates of large-diameter (femoral head sizes of 36 mm or greater) metal-on-metal hip arthroplasties (MoMHAs) have led to worldwide regulatory authorities recommending regular surveillance, even for asymptomatic individuals. However, these recommendations are not evidence-based and are very costly. The rapidly evolving evidence base requires an update regarding the investigation and management of MoMHA patients. This article is the first of 2 (the second article in this series will consider the threshold for performing revision, and the outcomes following ARMD revision surgery: Matharu et al., Revision surgery of metal-on-metal hip arthroplasties for adverse reactions to metal debris: A clinical update. Acta Orthop 2018; in press), and considers the various investigative modalities used during surveillance, with specific focus on blood metal ion sampling and cross-sectional imaging. No single investigation can universally be used during MoMHA patient surveillance. Recent studies have now provided important information on interpreting blood metal ions (effective in identifying patients at low risk of problems), clarifying the roles of cross-sectional imaging (reserve combined ultrasound and MARS-MRI for complex cases), and providing parameters to safely exclude many asymptomatic patients from regular surveillance. This information will be useful when designing future surveillance protocols for MoMHA patients.

Liposomal bupivacaine infiltration at the surgical site for the management of postoperative pain.

BACKGROUND: Despite multi-modal analgesic techniques, acute postoperative pain remains an unmet health need, with up to three quarters of people undergoing surgery reporting significant pain. Liposomal bupivacaine is an analgesic consisting of bupivacaine hydrochloride encapsulated within multiple, non-concentric lipid bi-layers offering a novel method of sustained-release analgesia. OBJECTIVES: To assess the analgesic efficacy and adverse effects of liposomal bupivacaine infiltration at the surgical site for the management of postoperative pain. SEARCH METHODS: On 13 January 2016 we searched CENTRAL, MEDLINE, MEDLINE In-Process, Embase, ISI Web of Science and reference lists of retrieved articles. We obtained clinical trial reports and synopses of published and unpublished studies from Internet sources, and searched clinical trials databases for ongoing trials. SELECTION CRITERIA: Randomised, double-blind, placebo- or active-controlled clinical trials in people aged 18 years or over undergoing elective surgery, at any surgical site, were included if they compared liposomal bupivacaine infiltration at the surgical site with placebo or other type of analgesia. DATA COLLECTION AND ANALYSIS: Two review authors independently considered trials for inclusion, assessed risk of bias, and extracted data. We performed data analysis using standard statistical techniques as described in the Cochrane Handbook for Systematic Reviews of Interventions, using Review Manager 5.3. We planned to perform a meta-analysis and produce a 'Summary of findings' table for each comparison however there were insufficient data to ensure a clinically meaningful answer. As such we have produced two 'Summary of findings' tables in a narrative format. Where possible we assessed the quality of evidence using GRADE. MAIN RESULTS: We identified nine studies (10 reports, 1377 participants) that met inclusion criteria. Four Phase II dose-escalating/de-escalating trials, designed to evaluate and demonstrate efficacy and safety, presented pooled data that we could not use. Of the remaining five parallel-arm studies (965 participants), two were placebo controlled and three used bupivacaine hydrochloride local anaesthetic infiltration as a control. Using the Cochrane tool, we judged most studies to be at unclear risk of bias overall; however, two studies were at high risk of selective reporting bias and four studies were at high risk of bias due to size (fewer than 50 participants per treatment arm).Three studies (551 participants) reported the primary outcome cumulative pain intensity over 72 hours following surgery. Compared to placebo, liposomal bupivacaine was associated with a lower cumulative pain score between the end of the operation (0 hours) and 72 hours (one study, very low quality). Compared to bupivacaine hydrochloride, two studies showed no difference for this outcome (very low quality evidence), however due to differences in the surgical population and surgical procedure (breast augmentation versus knee arthroplasty) we did not perform a meta-analysis.No serious adverse events were reported to be associated with the use of liposomal bupivacaine and none of the five studies reported withdrawals due to drug-related adverse events (moderate quality evidence).One study reported a lower mean pain score at 12 hours associated with liposomal bupivacaine compared to bupivacaine hydrochloride, but not at 24, 48 or 72 hours postoperatively (very low quality evidence).Two studies (382 participants) reported a longer time to first postoperative opioid dose compared to placebo (low quality evidence).Two studies (325 participants) reported the total postoperative opioid consumption over the first 72 hours: one study reported a lower cumulative opioid consumption for liposomal bupivacaine compared to placebo (very low quality evidence); one study reported no difference compared to bupivacaine hydrochloride (very low quality evidence).Three studies (492 participants) reported the percentage of participants not requiring postoperative opioids over initial 72 hours following surgery. One of the two studies comparing liposomal bupivacaine to placebo demonstrated a higher number of participants receiving liposomal bupivacaine did not require postoperative opioids (very low quality evidence). The other two studies, one versus placebo and one versus bupivacaine hydrochloride, found no difference in opioid requirement (very low quality evidence). Due to significant heterogeneity between the studies (I2 = 92%) we did not pool the results.All the included studies reported adverse events within 30 days of surgery, with nausea, constipation and vomiting being the most common. Of the five parallel-arm studies, none performed or reported health economic assessments or patient-reported outcomes other than pain.Using GRADE, the quality of evidence ranged from moderate to very low. The major limitation was the sparseness of data for outcomes of interest. In addition, a number of studies had a high risk of bias resulting in further downgrading. AUTHORS' CONCLUSIONS: Liposomal bupivacaine at the surgical site does appear to reduce postoperative pain compared to placebo, however, at present the limited evidence does not demonstrate superiority to bupivacaine hydrochloride. There were no reported drug-related serious adverse events and no study withdrawals due to drug-related adverse events. Overall due to the low quality and volume of evidence our confidence in the effect estimate is limited and the true effect may be substantially different from our estimate.

Poor Survivorship and Frequent Complications at a Median of 10 Years After Metal-on-Metal Hip Resurfacing Revision.

BACKGROUND: High short-term failure rates have been reported for several metal-on-metal hip resurfacing (MoMHR) designs. Early observations suggested that MoMHRs revised to total hip arthroplasties (THAs) for pseudotumor had more major complications and inferior patient-reported outcomes compared with other revision indications. However, little is known about implant survivorship and patient-reported outcomes at more than 5 years after MoMHR revision. QUESTIONS/PURPOSES: (1) What are the implant survivorship, proportion of complications and abnormal radiological findings, and patient-reported outcomes at a median of 10 years after MoMHR revision surgery? (2) Are survivorship, complications, and patient-reported outcomes influenced by revision indication? (3) Do any other factors predict survivorship, complications, and patient-reported outcomes? METHODS: Between 1999 and 2008, 53 MoMHR revision procedures in 51 patients (mean age, 55 years; 62% female) were performed at one center and were all included in this retrospective study. Two patients (4%) were lost to followup and two patients (4%) died before a minimum followup of 7 years (median, 10.3 years; range 7-15 years). Revision indications included pseudotumor (n = 16), femoral neck fracture (n = 21), and other causes (n = 16). In most cases (62%, n = 33) both components were revised to a non-MoM bearing THA with the remainder (38%, n = 20: fracture, loosening, or head collapse) undergoing femoral-only revision to a large-diameter MoM THA. Postrevision complications, rerevision, Oxford Hip Score (OHS), and UCLA score were determined using both a longitudinally maintained institutional database and postal questionnaire. Implant survivorship was assessed using the Kaplan-Meier method (endpoint was rerevision surgery). Radiographs at latest followup were systematically assessed for any signs of failure (loosening, migration, osteolysis) by one observer blinded to all clinical information and not involved in the revision procedures. RESULTS: Overall, 45% (24 of 53) experienced complications and 38% (20 of 53) underwent rerevision. Ten-year survival free from rerevision for revised MoMHRs was 63% (95% confidence interval [CI], 48%-74%). Revision indications were not associated with differences in the frequency of complications or repeat revisions. With the numbers available, 10-year survival free from rerevision for pseudotumor revisions (56%; 95% CI, 30%-76%) was not different from the fracture (68%; 95% CI, 42%-85%; p = 0.359) and other groups (63%; 95% CI, 35%-81%; p = 0.478). Pseudotumor revisions had inferior OHSs (median, 21; range, 2-46; p = 0.007) and UCLA scores (median, 2; range, 2-7; p = 0.0184) compared with fracture and other revisions. Ten-year survival free from rerevision after femoral-only revision using another large-diameter MoM bearing was lower (p = 0.0498) compared with all component revisions using non-MoM bearings. After controlling for potential confounding variables such as age, sex, and revision indication, we found femoral-only revision as the only factor predicting rerevision (hazard ratio, 5.7; 95% CI, 1.1-29; p = 0.040). CONCLUSIONS: Poor implant survivorship and frequent complications were observed at a median of 10 years after MoMHR revision. However, patients undergoing femoral-only revisions with large-diameter MoM bearings had the worst survivorship, whereas patients revised for pseudotumor had the most inferior patient-reported outcomes. Our findings suggest these two patient subgroups require regular surveillance after MoMHR revision. LEVEL OF EVIDENCE: Level III, therapeutic study.

Lateral osteophytes do not represent a contraindication to medial unicompartmental knee arthroplasty: a 15-year follow-up.

PURPOSE: Lateral osteophytes have been reported to be associated with lateral compartment disease and as such it is unclear whether medial unicompartmental knee arthroplasty should be performed if these are present. METHODS: Using the OARSI classification system, 0 (no osteophyte) to 3 (large osteophyte), radiographs from a series of cemented meniscal-bearing unicompartmental knee arthroplasty implanted in the setting of full-thickness lateral cartilage where lateral osteophytes were not considered a contraindication were identified and factors associated with the presence and size of lateral osteophytes, and their impact on clinical outcomes and implant survival were assessed. RESULTS: Pre-operative radiographs from 458 knees (392 patients), independently followed up for a mean 10.5 years (range 5.3-16.6), were assessed. Lateral osteophytes were present in 62 % of knees with 18 % scored as Grade 3. Inter-observer reliability was good (kappa = 0.70). The presence and size of lateral osteophytes was associated with younger age at joint replacement (p = 0.01) and increasing BMI (p = 0.01). No association was seen with gender, pre-operative status, assessed using the Oxford Knee Score (OKS), American Knee Society (AKSS) Objective or Functional Score, Tegner activity score, or size of medial tibial lesion. Subgroup analysis of Grade 3 Osteophytes revealed that these were associated with a greater degree of macroscopic ACL damage. At 10 years there was no difference in function (n.s.), and at 15 years no difference in implant survival or mechanism of failure between groups (n.s.). Subgroup analysis of Grade 3 osteophytes found no significant difference in functional outcome at 10 years or implant survival at 15 years. CONCLUSION: The presence of lateral osteophytes is not a contraindication to medial meniscal-bearing unicompartmental knee arthroplasty. The clinical relevance of this study is that it highlights the importance of an appropriate pre-operative assessment of the lateral compartment as in the setting of full-thickness cartilage at operation lateral osteophytes do not compromise long-term functional outcome or implant survival. LEVEL OF EVIDENCE: IV.

Evidence-Based Indications for Mobile-Bearing Unicompartmental Knee Arthroplasty in a Consecutive Cohort of Thousand Knees.

BACKGROUND: The indications for unicompartmental knee arthroplasty remain controversial. Previously recommended contraindications include the following: age under 60 years, weight 180 lb (82 kg) or over, patients undertaking heavy labor, chondrocalcinosis, and exposed bone in the patellofemoral joint. This study explores whether these contraindications are valid in mobile-bearing unicompartmental knee arthroplasty. METHODS: Using a prospective series of 1000 consecutive medial unicompartmental knee arthroplasties in which the reported contraindications were not applied, the functional outcome and survival in patients with or without contraindications were compared. RESULTS: Of the 1000 consecutive unicompartmental knee arthroplasties (818 patients), 68% (678 knees) would be considered contraindicated based on published contraindications. At a mean follow-up of 10 years (5-17), there was no difference in American Knee Society (AKS) Objective Scores (P = .05) or Oxford Knee Score (P = .08) between groups. However, knees with contraindications had significantly (P = .02) fewer poor outcomes and significantly better AKS Functional Scores (P < .001) and Tegner Activity Scores (P < .001). At 15 years, no difference in implant survival (P = .33) was observed. The 3% of unicompartmental knee arthroplasties performed in young men (age <60) weighing 180 lb or over with high activity levels, who have been reported to have poor outcomes after fixed-bearing unicompartmental knee arthroplasty, had significantly better AKS Functional Scores (P < .001), Oxford Knee Score (P = .01), and Tegner Activity Score (P < .001) at 10 years. No difference in AKS Objective Scores (P = .54) at 10 years or implant survival at 15 years (P = .75) was seen. CONCLUSION: This large case series provides evidence that patients with the previously reported contraindications do as well as, or even better than, those without contraindications. Therefore these contraindications should not apply to mobile-bearing unicompartmental knee arthroplasty.