In this study, we evaluated patient-reported outcomes, the rate of revision and the indications for revision following resurfacing hemiarthroplasty of the shoulder in patients with osteoarthritis. All patients with osteoarthritis who underwent primary resurfacing hemiarthroplasty and reported to the Danish Shoulder Arthroplasty Registry (DSR), between January 2006 and December 2010 were included. There were 772 patients (837 arthroplasties) in the study. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index was used to evaluate patient-reported outcome 12 months (10 to 14) post-operatively. The rates of revision were calculated from the revisions reported to the DSR up to December 2011 and by checking deaths with the Danish National Register of Persons. A complete questionnaire was returned by 688 patients (82.2%). The mean WOOS was 67 (0 to 100). A total of 63 hemiarthroplasties (7.5%) required revision; the cumulative five-year rate of revision was 9.9%. Patients aged < 55 years had a statistically significant inferior WOOS score, which exceeded the minimal clinically important difference, compared with older patients (mean difference 14.2 (8.8; 95% CI 19.6; p < 0.001), but with no increased risk of revision. There was no significant difference in the mean WOOS or the risk of revision between designs of resurfacing hemiarthroplasty. Cite this article: Bone Joint J 2014;96-B:519–25

Revision of a cemented hemiarthroplasty of the hip may be a hazardous procedure with high rates of intra-operative complications. Removing well-fixed cement is time consuming and risks damaging already weak bone or perforating the femoral shaft. The cement-in-cement method avoids removal of intact cement and has shown good results when used for revision total hip arthroplasty (THA). The use of this technique for the revision of a hemiarthroplasty to THA has not been previously reported. A total of 28 consecutive hemiarthroplasties (in 28 patients) were revised to a THA using an Exeter stem and the cement-in-cement technique. There were four men and 24 women; their mean age was 80 years (35 to 93). Clinical and radiographic data, as well as operative notes, were collected prospectively and no patient was lost to follow-up. Four patients died within two years of surgery. The mean follow up of the remainder was 70 months (25 to 124). Intra-operatively there was one proximal perforation, one crack of the femoral calcar and one acetabular fracture. No femoral components have required subsequent revision for aseptic loosening or are radiologically loose. . Four patients with late complications (14%) have since undergone surgery (two for a peri-prosthetic fracture, and one each for deep infection and recurrent dislocation) resulting in an overall major rate of complication of 35.7%. The cement-in-cement technique provides reliable femoral fixation in this elderly population and may reduce operating time and rates of complication. Cite this article: Bone Joint J 2015;97-B:1623–7

If a surgeon is faced with altered lesser trochanter anatomy when revising the femoral component in revision total hip replacement, a peri-prosthetic fracture, or Paprosky type IIIb or type IV femoral bone loss, a modular tapered stem offers the advantages of accurately controlling femoral version and length. The splines of the taper allow rotational control, and improve the fit in femoral canals with diaphyseal bone loss. In general, two centimetres of diaphyseal contact is all that is needed to gain stability with modular tapered stems. By allowing the proximal body trial to rotate on a well-fixed distal segment during trial reduction, appropriate anteversion can be obtained in order to improve intra-operative stability, and decrease the dislocation risk. However, modular stems should not be used for all femoral revisions, as implant fracture and corrosion at modular junctions can still occur. Cite this article: Bone Joint J 2013;95-B, Supple A:95–7

Aims. The Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon’s consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years. Methods. The study extends the reporting on the first consecutive 144 resurfacing procedures in 130 patients for all indications. All operations were undertaken between August 1997 and May 1998. The mean age at operation was 52.1 years (SD 9.93; 17 to 76), and included 37 female patients (28.5%). Failure was defined as revision of either component for any reason. Kaplan-Meier survival analysis was performed. Routine follow-up with serum metal ion levels, radiographs, and Oxford Hip Scores (OHSs) was undertaken. Results. Overall implant survival was 83.50% (95% confidence interval (CI) 0.79 to 0.90) at 25 years, and the number at risk was 79. Survival in male patients at 25 years was 89.5% (95% CI 0.83 to 0.96) compared to 66.9% for female patients (95% CI 0.51 to 0.83). Ten additional failures occurred in the period of ten to 25 years. These involved an adverse reaction to metal debris in four patients, a periprosthetic femoral neck fracture affecting five patients, and aseptic loosening in one patient. The median chromium levels were 49.50 nmol/l (interquartile range (IQR) 34 to 70), and the median cobalt serum levels were 42 nmol/l (IQR 24.50 to 71.25). The median OHS at last follow-up was 35 (IQR 10 to 48). During the 25-year study period, 29 patients died. Patient survival at 25 years was 75.10% (95% CI 0.67 to 0.83). Conclusion. This study demonstrates that MoM hip resurfacing using the BHR provides a durable alternative to total hip arthroplasty (THA), particularly in younger male patients with osteoarthritis wishing to maintain a high level of function. These results compare favourably to the best results for THAs. Cite this article: Bone Joint J 2024;106-B(6):540–547

Aims. The outcome of repeat septic revision after a failed one-stage exchange for periprosthetic joint infection (PJI) in total knee arthroplasty (TKA) remains unknown. The aim of this study was to report the infection-free and all-cause revision-free survival of repeat septic revision after a failed one-stage exchange, and to determine whether the Musculoskeletal Infection Society (MSIS) stage is associated with subsequent infection-related failure. Methods. We retrospectively reviewed all repeat septic revision TKAs which were undertaken after a failed one-stage exchange between 2004 and 2017. A total of 33 repeat septic revisions (29 one-stage and four two-stage) met the inclusion criteria. The mean follow-up from repeat septic revision was 68.2 months (8.0 months to 16.1 years). The proportion of patients who had a subsequent infection-related failure and all-cause revision was reported and Kaplan-Meier survival for these endpoints was determined. Patients were categorized according to the MSIS staging system, and the association with subsequent infection was analyzed. Results. At the most recent follow-up, 17 repeat septic revisions (52%) had a subsequent infection-related failure and the five-year infection-free survival was 59% (95% confidence interval (CI) 39 to 74). A total of 19 underwent a subsequent all-cause revision (58%) and the five-year all-cause revision-free survival was 47% (95% CI 28 to 64). The most common indication for the first subsequent aseptic revision was loosening. The MSIS stage of the host status (p = 0.663) and limb status (p = 1.000) were not significantly associated with subsequent infection-related failure. Conclusion. Repeat septic revision after a failed one-stage exchange TKA for PJI is associated with a high rate of subsequent infection-related failure and all-cause revision. Patients should be counselled appropriately to manage expectations. The host and limb status according to the MSIS staging system were not associated with subsequent infection-related failure. Cite this article: Bone Joint J 2022;104-B(3):386–393

Aims. The purpose of this study is to examine six types of bearing surfaces implanted at a single institution over three decades to determine whether the reasons for revision vary among the groups and how long it takes to identify differences in survival. Methods. We considered six cohorts that included a total of 1,707 primary hips done between 1982 and 2010. These included 223 conventional polyethylene sterilized with γ irradiation in air (CPE-GA), 114 conventional polyethylene sterilized with gas plasma (CPE-GP), 116 crosslinked polyethylene (XLPE), 1,083 metal-on-metal (MOM), 90 ceramic-on-ceramic (COC), and 81 surface arthroplasties (SAs). With the exception of the COC, all other groups used cobalt-chromium (CoCr) femoral heads. The mean follow-up was 10 (0.008 to 35) years. Descriptive statistics with revisions per 100 component years (re/100 yr) and survival analysis with revision for any reason as the endpoint were used to compare bearing surfaces. Results. XLPE liners demonstrated a lower cumulative incidence of revision at 15 years compared to the CPE-GA and CPE-GP groups owing to the absence of wear-related revisions (4% for XLPE vs 18%, p = 0.02, and 15%, p = 0.003, respectively). Revisions for adverse local tissue reactions occurred exclusively among the MOM (0.8 re/100 year) and SA groups (0.1 re/100 year). The revision rate for instability was lower among hips with 36 mm and larger head sizes compared to smaller head sizes (0.2% vs 2%, p < 0.001). Conclusion. The introduction of XLPE has eliminated wear-related revisions through 15-year follow-up compared to CPE-GP and CPE-GA. Dislocation incidence has been reduced with the introduction of larger diameter heads but remains a persistent concern. The potential for adverse local tissue reactions with MOM requires continued follow-up. Cite this article: Bone Joint J 2020;102-B(7 Supple B):105–111

Aims. The number of revision total ankle arthroplasties (TAAs) which are undertaken is increasing. Few studies have reported the survival after this procedure. The primary aim of this study was to analyze the survival of revision ankle arthroplasties using large datasets. Secondary aims were to summarize the demographics of the patients, the indications for revision TAA, further operations, and predictors of survival. Methods. The study combined data from the National Joint Registry and NHS Digital to report the survival of revision TAA. We have previously reported the failure rates and risk factors for failure after TAA, and the outcome of fusion after a failed TAA, using the same methodology. Survival was assessed using life tables and Kaplan Meier graphs. Cox proportional hazards regression models were fitted to compare failure rates. Results. A total of 228 patients underwent revision TAA. The mean follow-up was 2.6 years (SD 2.0). The mean time between the initial procedure and revision was 2.3 years (SD 1.8). The most commonly used implant was the Inbone which was used in 81 patients. A total of 29 (12.7%) failed; nine (3.9%) patients underwent a further revision, 19 (8.3%) underwent a fusion, and one (0.4%) had an amputation. The rate of survival was 95.4% (95% confidence interval (CI) 91.6 to 97.5) at one year, 87.7% (95% CI 81.9 to 91.7; n = 124) at three years and 77.5% (95% CI 66.9 to 85.0; n = 57) at five years. Revision-specific implants had a better survival than when primary implants were used at revision. A total of 50 patients (21.9%) had further surgery; 19 (8.3%) underwent reoperation in the first 12 months. Cox regression models were prepared. In crude analysis the only significant risk factors for failure were the use of cement (hazard ratio (HR) 3.02 (95% CI 1.13 to 8.09)) and the time since the primary procedure (HR 0.67 (95% CI 0.47 to 0.97)). No risk factors for failure were identified in multivariable Cox regression modelling. Conclusion. Revision TAAs have good medium term survival and low rates of further surgery. New modular revision implants appear to have improved the survival compared with the use of traditional primary implants at revision. Cite this article: Bone Joint J 2023;105-B(11):1184–1188

Aims. Removal of infected components and culture-directed antibiotics are important for the successful treatment of chronic periprosthetic joint infection (PJI). However, as many as 27% of chronic PJI patients yield negative culture results. Although culture negativity has been thought of as a contraindication to one-stage revision, data supporting this assertion are limited. The aim of our study was to report on the clinical outcomes for one-stage and two-stage exchange arthroplasty performed in patients with chronic culture-negative PJI. Methods. A total of 105 consecutive patients who underwent revision arthroplasty for chronic culture-negative PJI were retrospectively evaluated. One-stage revision arthroplasty was performed in 30 patients, while 75 patients underwent two-stage exchange, with a minimum of one year's follow-up. Reinfection, re-revision for septic and aseptic reasons, amputation, readmission, mortality, and length of stay were compared between the two treatment strategies. Results. The patient demographic characteristics did not differ significantly between the groups. At a mean follow-up of 4.2 years, the treatment failure for reinfection for one-stage and two-stage revision was five (16.7%) and 15 patients (20.0%) (p = 0.691), and for septic re-revision was four (13.3%) and 11 patients (14.7%) (p = 0.863), respectively. No significant differences were observed between one-stage and two-stage revision for 30- 60- and 90-day readmissions (10.0% vs 8.0%; p = 0.714; 16.7% vs 9.3%; p = 0.325; and 26.7% vs 10.7%; p = 0.074), one-year mortality (3.3% vs 4.0%; p > 0.999), and amputation (3.3% vs 1.3%; p = 0.496). Conclusion. In this non-randomized study, one-stage revision arthroplasty demonstrated similar outcomes including reinfection, re-revision, and readmission rates for the treatment of chronic culture-negative PJI after TKA and THA compared to two-stage revision. This suggests culture negativity may not be a contraindication to one-stage revision arthroplasty for chronic culture-negative PJI in selected patients. Cite this article: Bone Joint J 2021;103-B(3):515–521

Aims. The aim of this study was to identify variables associated with time to revision, demographic details associated with revision indication, and type of prosthesis employed, and to describe the survival of hinge knee arthroplasty (HKA) when used for first-time knee revision surgery and factors that were associated with re-revision. Methods. Patient demographic details, BMI, American Society of Anesthesiologists (ASA) grade, indication for revision, surgical approach, surgeon grade, implant type (fixed and rotating), time of revision from primary implantation, and re-revision if undertaken were obtained from the National Joint Registry data for England, Wales, Northern Ireland, and the Isle of Man over an 18-year period (2003 to 2021). Results. There were 3,855 patient episodes analyzed with a median age of 73 years (interquartile range (IQR) 66 to 80), and the majority were female (n = 2,480, 64.3%). The median time to revision from primary knee arthroplasty was 1,219 days (IQR 579 to 2,422). Younger age (p < 0.001), decreasing ASA grade (p < 0.001), and indications for revision of sepsis (p < 0.001), unexplained pain (p < 0.001), non-polyethylene wear (p < 0.001), and malalignment (p < 0.001) were all associated with an earlier time to revision from primary implantation. The median follow-up was 4.56 years (range 0.00 to 17.52), during which there were 410 re-revisions. The overall unadjusted probability of re-revision for all revision HKAs at one, five, and ten years after surgery were 2.7% (95% confidence interval (CI) 2.2 to 3.3), 10.7% (95% CI 9.6 to 11.9), and 16.2% (95% CI 14.5 to 17.9), respectively. Male sex (p < 0.001), younger age (p < 0.001), revision for septic indications (p < 0.001) or implant fracture (p = 0.010), a fixed hinge (p < 0.001), or surgery performed by a non-consultant grade (p = 0.023) were independently associated with an increased risk of re-revision. Conclusion. There were several factors associated with time to first revision. The re-revision rate was 16.2% at ten years; however, the risk factors associated with an increased risk of re-revision could be used to counsel patients regarding their outcome. Cite this article: Bone Joint J 2023;105-B(1):47–55

Aims. Unicompartmental knee arthroplasty (UKA) has higher revision rates than total knee arthroplasty (TKA). As revision of UKA may be less technically demanding than revision TKA, UKA patients with poor functional outcomes may be more likely to be offered revision than TKA patients with similar outcomes. The aim of this study was to compare clinical thresholds for revisions between TKA and UKA using revision incidence and patient-reported outcomes, in a large, matched cohort at early, mid-, and late-term follow-up. Methods. Analyses were performed on propensity score-matched patient cohorts of TKAs and UKAs (2:1) registered in the New Zealand Joint Registry between 1 January 1999 and 31 December 2019 with an Oxford Knee Score (OKS) response at six months (n, TKA: 16,774; UKA: 8,387), five years (TKA: 6,718; UKA: 3,359), or ten years (TKA: 3,486; UKA: 1,743). Associations between OKS and revision within two years following the score were examined. Thresholds were compared using receiver operating characteristic analysis. Reasons for aseptic revision were compared using cumulative incidence with competing risk. Results. Fewer TKA patients with ‘poor’ outcomes (≤ 25) subsequently underwent revision compared with UKA at six months (5.1% vs 19.6%; p < 0.001), five years (4.3% vs 12.5%; p < 0.001), and ten years (6.4% vs 15.0%; p = 0.024). Compared with TKA, the relative risk for UKA was 2.5-times higher for ‘unknown’ reasons, bearing dislocations, and disease progression. Conclusion. Compared with TKA, more UKA patients with poor outcomes underwent revision from early to long-term follow-up, and were more likely to undergo revision for ‘unknown’ reasons, which suggest a lower clinical threshold for UKA. For UKA, revision risk was higher for bearing dislocations and disease progression. There is supporting evidence that the higher revision UKA rates are associated with lower clinical thresholds for revision and additional modes of failure. Cite this article: Bone Joint J 2023;105-B(3):269–276

Aims. Unicompartmental knee arthroplasty (UKA) has a higher risk of revision than total knee arthroplasty (TKA), particularly for younger patients. The outcome of knee arthroplasty is typically defined as implant survival or revision incidence after a defined number of years. This can be difficult for patients to conceptualize. We aimed to calculate the ‘lifetime risk’ of revision for UKA as a more meaningful estimate of risk projection over a patient’s remaining lifetime, and to compare this to TKA. Methods. Incidence of revision and mortality for all primary UKAs performed from 1999 to 2019 (n = 13,481) was obtained from the New Zealand Joint Registry (NZJR). Lifetime risk of revision was calculated for patients and stratified by age, sex, and American Society of Anesthesiologists (ASA) grade. Results. The lifetime risk of revision was highest in the youngest age group (46 to 50 years; 40.4%) and decreased sequentially to the oldest (86 to 90 years; 3.7%). Across all age groups, lifetime risk of revision was higher for females (ranging from 4.3% to 43.4% vs males 2.9% to 37.4%) and patients with a higher ASA grade (ASA 3 to 4, ranging from 8.8% to 41.2% vs ASA 1 1.8% to 29.8%). The lifetime risk of revision for UKA was double that of TKA across all age groups (ranging from 3.7% to 40.4% for UKA, and 1.6% to 22.4% for TKA). The higher risk of revision in younger patients was associated with aseptic loosening in both sexes and pain in females. Periprosthetic joint infection (PJI) accounted for 4% of all UKA revisions, in contrast with 27% for TKA; the risk of PJI was higher for males than females for both procedures. Conclusion. Lifetime risk of revision may be a more meaningful measure of arthroplasty outcomes than implant survival at defined time periods. This study highlights the higher lifetime risk of UKA revision for younger patients, females, and those with a higher ASA grade, which can aid with patient counselling prior to UKA. Cite this article: Bone Joint J 2022;104-B(6):672–679

Aims. The aim of this study was to perform a systematic review of the evidence for the use of intraoperative cell salvage in patients undergoing revision hip arthroplasty, and specifically to analyze the available data in order to quantify any associated reduction in the use of allogenic blood transfusion, and the volume which is used. Methods. An electronic search of MEDLINE (PubMed), Embase, Scopus, and the Cochrane Library was completed from the date of their inception to 24 February 2022, using a search strategy and protocol created in conjunction with the PRISMA statement. Inclusion criteria were patients aged > 18 years who underwent revision hip arthroplasty when cell salvage was used. Studies in which pre-donated red blood cells were used were excluded. A meta-analysis was also performed using a random effects model with significance set at p = 0.05. Results. Of the 283 studies which were identified, 11 were included in the systematic review, and nine in the meta-analysis. There was a significant difference (p < 0.001) in the proportion of patients requiring allogenic transfusion between groups, with an odds ratio of 0.331 (95% confidence interval (CI) 0.165 to 0.663) associated with the use of cell salvage. For a total of 561 patients undergoing revision hip arthroplasty who were treated with cell salvage, 247 (44.0%) required allogenic transfusion compared with 418 of 643 patients (65.0%) who were treated without cell salvage. For those treated with cell salvage, the mean volume of allogenic blood which was required was 1.95 units (390 ml) per patient (0.7 to 4.5 units), compared with 3.25 units (650 ml) per patient (1.2 to 7.0 units) in those treated without cell salvage. The mean difference of -1.91 units (95% CI -4.0 to 0.2) in the meta-analysis was also significant (p = 0.003). Conclusion. We found a a significant reduction in the need for allogenic blood transfusion when cell salvage was used in patients undergoing revision hip arthroplasty, supporting its routine use in these patients. Further research is required to determine whether this effect is associated with types of revision arthroplasty of differing complexity. Cite this article: Bone Joint J 2023;105-B(10):1038–1044

Aims. Reverse shoulder arthroplasty (RSA) has become the most common type of shoulder arthroplasty used in the UK, and a better understanding of the outcomes after revision of a failed RSA is needed. The aim of this study was to review the current evidence systematically to determine patient-reported outcome measures and the rates of re-revision and complications for patients undergoing revision of a RSA. Methods. MEDLINE, Embase, CENTRAL, and the Cochrane Database of Systematic Reviews were searched. Studies involving adult patients who underwent revision of a primary RSA for any indication were included. Those who underwent a RSA for failure of a total shoulder arthroplasty or hemiarthroplasty were excluded. Pre- and postoperative shoulder scores were evaluated in a random effects meta-analysis to determine the mean difference. The rates of re-revision and complications were also calculated. Results. The initial search elicited 3,166 results and, following removal of duplicates and screening, 13 studies with a total of 1,042 RSAs were identified. An increase in shoulder scores pre- to postoperatively was reported in all the studies. Following revision of a RSA to a further RSA, there was a significant increase in the American Shoulder and Elbow Surgeons Score (mean difference 20.78 (95% CI 8.16 to 33.40); p = 0.001). A re-revision rate at final follow-up ranging from 9% to 32%, a one-year re-revision rate of 14%, and a five-year re-revision rate of 23% were reported. The complication rate in all the studies was between 18.5% and 36%, with a total incidence of 29%. Conclusion. This is the largest systematic review of the outcomes following revision of a RSA. We found an improvement in functional outcomes after revision surgery, but the rates of re-revision and complications are high and warrant consideration when planning a revision procedure. Cite this article: Bone Joint J 2024;106-B(11):1293–1300

Aims. There are limited long-term studies reporting on outcomes of the Zimmer Modular Revision (ZMR) stem, and concerns remain regarding failure. Our primary aim was to determine long-term survival free from all-cause revision and stem-related failure for this modular revision stem in revision total hip arthroplasty (THA). Secondary aims included evaluating radiological and functional outcomes. Methods. We retrospectively identified all patients in our institutional database who underwent revision THA using the ZMR system from January 2000 to December 2007. We included 106 patients (108 hips) with a mean follow-up of 14.5 years (2.3 to 22.3). Mean patient age was 69.2 years (37.0 to 89.4), and 51.9% were female (n = 55). Indications for index revision included aseptic loosening (73.1%), infection (16.7%), fracture (9.3%), and stem fracture (0.9%). Kaplan-Meier analysis was used to determine the all-cause and stem-related failure revision-free survival. At most recent follow-up, Oxford Hip Scores (OHS) were collected, and radiological stem stability was determined using the Engh classification. Results. A total of 17 hips (15.7%) underwent re-revision of any component. Indications for re-revision were stem failure (35.3%; n = 6), infection (29.4%; n = 5), instability (29.4%; n = 5), and acetabular aseptic loosening (5.9%; n = 1). The five- and 15-year all-cause survival was 89.7% (95% confidence interval (CI) 86.7 to 92.7) and 83.3% (95% CI 79.6 to 87.0), respectively. There were six re-revisions (5.6%) for stem failure; five for stem fracture and one for aseptic loosening. The five- and 15-year survival free from stem-related failure was 97.2% (95% CI 95.6 to 98.8) and 94.0% (95% CI 91.6 to 96.4), respectively. At final follow-up, the mean OHS was 36.9 (8.0 to 48.0) and 95.7% (n = 66) of surviving modular revision stems were well-fixed in available radiographs. Conclusion. Femoral revision with the ZMR offers satisfactory long-term all-cause revision-free survival, good survival free of stem-related failure, and favourable clinical outcomes. Stem fracture was the most common reason for stem-related failure and occurred both early and late. This highlights the importance of both early and long-term surveillance for stem-related failure. Cite this article: Bone Joint J 2024;106-B(5 Supple B):112–117

Aims. Periprosthetic joint infection (PJI) is a challenging complication of any arthroplasty procedure. We reviewed our use of static antibiotic-loaded cement spacers (ABLCSs) for staged management of PJI where segmental bone loss, ligamentous instability, or soft-tissue defects necessitate a static construct. We reviewed factors contributing to their failure and techniques to avoid these complications when using ABLCSs in this context. Methods. A retrospective analysis was conducted of 94 patients undergoing first-stage revision of an infected knee prosthesis between September 2007 and January 2020 at a single institution. Radiographs and clinical records were used to assess and classify the incidence and causes of static spacer failure. Of the 94 cases, there were 19 primary total knee arthroplasties (TKAs), ten revision TKAs (varus-valgus constraint), 20 hinged TKAs, one arthrodesis (nail), one failed spacer (performed elsewhere), 21 distal femoral endoprosthetic arthroplasties, and 22 proximal tibial arthroplasties. Results. A total of 35/94 patients (37.2%) had spacer-related complications, of which 26/35 complications (74.3%) were because of mechanical failure of the spacer construct, while 9/35 (25.7%) were due to recurrence of infection. Risk factors for internal failure were a construct where the total intramedullary spacer length was less than twice the length of the central osseous defect (p = 0.009), where proximal or distal intraosseous spacer contact was < 10%, and after tibial tubercle osteotomy (p = 0.005). The incidence of spacer complications significantly increased the time to second stage: mean 157 days (42 to 458) in those without complications versus 227 days (11 to 528) with complications (p = 0.014). Conclusion. The failure rate of static antibiotic-loaded cement spacers is much higher than anticipated. Complications of the spacer significantly increased the time to second-stage revision. The risk of mechanical failure is significantly increased if the spacer is less than double the size of the segmental defect, or if inadequate reinforcement is inserted into the residual bone. These findings serve as a guide for surgeons to avoid mechanical complications with static spacers. Cite this article: Bone Joint J 2024;106-B(10):1067–1073

Aims. Metal and ceramic humeral head bearing surfaces are available choices in anatomical shoulder arthroplasties. Wear studies have shown superior performance of ceramic heads, however comparison of clinical outcomes according to bearing surface in total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) is limited. This study aimed to compare the rates of revision and reoperation following metal and ceramic humeral head TSA and HA using data from the National Joint Registry (NJR), which collects data from England, Wales, Northern Ireland, Isle of Man and the States of Guernsey. Methods. NJR shoulder arthroplasty records were linked to Hospital Episode Statistics and the National Mortality Register. TSA and HA performed for osteoarthritis (OA) in patients with an intact rotator cuff were included. Metal and ceramic humeral head prostheses were matched within separate TSA and HA groups using propensity scores based on 12 and 11 characteristics, respectively. The primary outcome was time to first revision and the secondary outcome was non-revision reoperation. Results. A total of 4,799 TSAs (3,578 metal, 1,221 ceramic) and 1,363 HAs (1,020 metal, 343 ceramic) were included. The rate of revision was higher for metal compared with ceramic TSA, hazard ratio (HR) 3.31 (95% confidence interval (CI) 1.67 to 6.58). At eight years, prosthesis survival for ceramic TSA was 98.7% (95% CI 97.3 to 99.4) compared with 96.4% (95% CI 95.2 to 97.3) for metal TSA. The majority of revision TSAs were for cuff insufficiency or instability/dislocation. There was no significant difference in the revision rate for ceramic compared with metal head HA (HR 1.33 (95% CI 0.76 to 2.34)). For ceramic HA, eight-year prosthetic survival was 92.8% (95% CI 86.9 to 96.1), compared with 91.6% (95% CI 89.3 to 93.5) for metal HA. The majority of revision HAs were for cuff failure. Conclusion. The rate of all-cause revision was higher following metal compared with ceramic humeral head TSA in patients with OA and an intact rotator cuff. There was no difference in the revision rate for HA according to bearing surface. Cite this article: Bone Joint J 2024;106-B(5):482–491

Aims. Dislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct. Methods. We identified 64 patients (65 hips) who had a single-design cemented DM cup cemented into an uncemented acetabular shell during revision THA between 2018 and 2020 at our institution. Cups were cemented into either uncemented cups designed for liner cementing (n = 48; 74%) or retained (n = 17; 26%) acetabular components. Median outer head diameter was 42 mm. Mean age was 69 years (SD 11), mean BMI was 32 kg/m. 2. (SD 8), and 52% (n = 34) were female. Survival was assessed using Kaplan-Meier methods. Mean follow-up was two years (SD 0.97). Results. There were nine cemented DM cup revisions: three for periprosthetic joint infection, three for acetabular aseptic loosening from bone, two for dislocation, and one for a broken cup-cage construct. The two-year survivals free of aseptic DM revision and dislocation were both 92%. There were five postoperative dislocations, all in patients with prior dislocation or abductor deficiency. On radiological review, the DM cup remained well-fixed at the cemented interface in all but one case. Conclusion. While dislocation was not eliminated in this series of complex revision THAs, this technique allowed for maximization of femoral head diameter and optimization of effective acetabular component position during cementing. Of note, there was only one failure at the cemented interface. Cite this article: Bone Joint J 2024;106-B(4):352–358

Aims. Nonagenarians (aged 90 to 99 years) have experienced the fastest percent decile population growth in the USA recently, with a consequent increase in the prevalence of nonagenarians living with joint arthroplasties. As such, the number of revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) in nonagenarians is expected to increase. We aimed to determine the mortality rate, implant survivorship, and complications of nonagenarians undergoing aseptic revision THAs and revision TKAs. Methods. Our institutional total joint registry was used to identify 96 nonagenarians who underwent 97 aseptic revisions (78 hips and 19 knees) between 1997 and 2018. The most common indications were aseptic loosening and periprosthetic fracture for both revision THAs and revision TKAs. Mean age at revision was 92 years (90 to 98), mean BMI was 27 kg/m. 2. (16 to 47), and 67% (n = 65) were female. Mean time between primary and revision was 18 years (SD 9). Kaplan-Meier survival was used for patient mortality, and compared to age- and sex-matched control populations. Reoperation risk was assessed using cumulative incidence with death as a competing risk. Mean follow-up was five years. Results. Mortality rates were 9%, 18%, 26%, and 62% at 90 days, one year, two years, and five years, respectively, but similar to control populations. There were 43 surgical complications and five reoperations, resulting in a cumulative incidence of reoperation of 4% at five years. Medical complications were common, with a cumulative incidence of 65% at 90 days. Revisions for periprosthetic fractures were associated with higher mortality and higher 90-day risk of medical complications compared to revisions for aseptic loosening. Conclusion. Contemporary revision THAs and TKAs appeared to be relatively safe in selected nonagenarians managed with multidisciplinary teams. Cause of revision affected morbidity and mortality risks. While early medical and surgical complications were frequent, they seldom resulted in reoperation. Cite this article: Bone Joint J 2023;105-B(6):649–656

Aims. Histology is widely used for diagnosis of persistent infection during reimplantation in two-stage revision hip and knee arthroplasty, although data on its utility remain scarce. Therefore, this study aims to assess the predictive value of permanent sections at reimplantation in relation to reinfection risk, and to compare results of permanent and frozen sections. Methods. We retrospectively collected data from 226 patients (90 hips, 136 knees) with periprosthetic joint infection who underwent two-stage revision between August 2011 and September 2021, with a minimum follow-up of one year. Histology was assessed via the SLIM classification. First, we analyzed whether patients with positive permanent sections at reimplantation had higher reinfection rates than patients with negative histology. Further, we compared permanent and frozen section results, and assessed the influence of anatomical regions (knee versus hip), low- versus high-grade infections, as well as first revision versus multiple prior revisions on the histological result at reimplantation. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), chi-squared tests, and Kaplan-Meier estimates were calculated. Results. Overall, the reinfection rate was 18%. A total of 14 out of 82 patients (17%) with positive permanent sections at reimplantation experienced reinfection, compared to 26 of 144 patients (18%) with negative results (p = 0.996). Neither permanent sections nor fresh frozen sections were significantly associated with reinfection, with a sensitivity of 0.35, specificity of 0.63, PPV of 0.17, NPV of 0.81, and accuracy of 58%. Histology was not significantly associated with reinfection or survival time for any of the analyzed sub-groups. Permanent and frozen section results were in agreement for 91% of cases. Conclusion. Permanent and fresh frozen sections at reimplantation in two-stage revision do not serve as a reliable predictor for reinfection. Cite this article: Bone Joint J 2024;106-B(4):372–379

Aims. The success of total knee arthroplasty (TKA) is usually measured using functional outcome scores and revision-free survivorship. However, reporting the lifetime risk of revision may be more meaningful to patients when gauging risks, especially in younger patients. We aimed to assess the lifetime risk of revision for patients in different age categories at the time of undergoing primary TKA. Methods. The New Zealand Joint Registry database was used to obtain revision rates, mortality, and the indications for revision for all primary TKAs performed during an 18-year period between January 1999 and December 2016. Patients were stratified into age groups at the time of the initial TKA, and the lifetime risk of revision was calculated according to age, sex, and the American Society of Anesthesiologists (ASA) grade. The most common indications for revision were also analyzed for each age group. Results. The overall ten-year survival rate was 95.6%. This was lowest in the youngest age group (between 46 and 50 years) and increased sequentially with increasing age. The lifetime risk of requiring revision was 22.4% in those aged between 46 and 50 years at the time of the initial surgery, and decreased linearly with increasing age to 1.15% in those aged between 90 and 95 years at the time of surgery. Higher ASA grades were associated with increased lifetime risk of revision in all age groups. The three commonest indications for revision were aseptic loosening, infection, and unexplained pain. Young males, aged between 46 and 50 years, had the highest lifetime risk of revision (25.2%). Conclusion. Lifetime risk of revision may be a more meaningful measure of outcome than implant survival at defined time periods when counselling patients prior to TKA. This study highlights the considerably higher lifetime risk of revision surgery for all indications, including infection, in younger male patients. Cite this article: Bone Joint J 2022;104-B(2):235–241

Aims. The aim of this study was to assess factors associated with the estimated lifetime risk of revision surgery after primary knee arthroplasty (KA). Methods. All patients from the Scottish Arthroplasty Project dataset undergoing primary KA during the period 1 January 1998 to 31 December 2019 were included. The cumulative incidence function for revision and death was calculated up to 20 years. Adjusted analyses used cause-specific Cox regression modelling to determine the influence of patient factors. The lifetime risk was calculated as a percentage for patients aged between 45 and 99 years using multiple-decrement life table methodology. Results. The estimated lifetime risk of revision ranged between 32.7% (95% confidence interval (CI) 22.6 to 47.3) for patients aged 45 to 49 years and 0.6% (95% CI 0.1 to 4.5) for patients aged over 90 years. At 20 years, the overall cumulative incidence of revision (6.8% (95% CI 6.6 to 7.0)) was significantly less than that of death (66.3% (95% CI 65.4 to 67.1)). Adjusted analyses demonstrated converse effect of increasing age on risk of revision (hazard ratio (HR) 0.5 (95% CI 0.5 to 0.6)) and death (HR 3.6 (95% CI 3.4 to 3.7)). Male sex was associated with increased risks of revision (HR 1.1 (95% CI 1.1 to 1.2); p < 0.001) and death (HR 1.4 (95% CI 1.3 to 1.4); p < 0.001). Compared to patients undergoing primary KA for osteoarthritis, patients with inflammatory arthropathy had a higher risk of death (HR 1.7 (95% CI 1.7 to 1.8); p < 0.001), but were less likely to be revised (HR 0.9 (95% CI 0.7 to 1.0); p < 0.001). Patients with a greater number of comorbidities (HR 1.4 (95% CI 1.3 to 1.4)) and greater levels of socioeconomic deprivation (HR 1.4 (95% CI 1.4 to 1.5)) were at increased risk of death, but neither increased the risk of revision. Conclusion. The estimated lifetime risk of revision KA varied depending on patient sex, age, and underlying diagnosis. Patients aged between 45 and 49 years had a one in three risk of undergoing revision surgery within their lifetime, which decreased with age to one in 159 in those aged 90 years or more. Cite this article: Bone Joint J 2022;104-B(12):1313–1322

Aims. Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients. Methods. A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem. Results. The design of the stem was found to have no significant influence on the rate of revision for either sex in the Young group. Uncemented collared stems had a significantly lower rate of revision compared with the other types of stem for females in the Mid-I group. There was a significantly higher rate of revision for uncemented stems in females in the Mid-II group compared with all other types of stem, while in males the rate for uncemented stems was only significantly higher than the rate for cemented stems. Cemented stems had a significantly lower revision rate compared with uncemented and short stems for both sexes in the Old cohort, as did females with collared stems. The rate of immediate postoperative mortality was similar for all types of stem in the Old age group, as were the American Society of Anesthesiologists grades. Conclusion. In patients aged > 80 years, uncemented and short stems had significantly higher revision rates compared with cemented and collared stems, especially in females. The design of the stem and type of fixation have to be analyzed in more detail than only considering cemented and uncemented fixation, in order to further improve the success of THA. Cite this article: Bone Joint J 2024;106-B(3 Supple A):130–136

Aims. This study aimed to describe the use of revision knee arthroplasty in Australia and examine changes in lifetime risk over a decade. Methods. De-identified individual-level data on all revision knee arthroplasties performed in Australia from 2007 to 2017 were obtained from the Australian Orthopaedic Association National Joint Replacement Registry. Population data and life tables were obtained from the Australian Bureau of Statistics. The lifetime risk of revision surgery was calculated for each year using a standardized formula. Separate calculations were undertaken for males and females. Results. In total, 43,188 revision knee arthroplasty procedures were performed in Australia during the study period, with a median age at surgery of 69 years (interquartile range (IQR) 62 to 76). In 2017, revision knee arthroplasty rates were highest for males aged 70 to 79 years (102.9 procedures per 100,000 population). Lifetime risk of revision knee arthroplasty for females increased slightly from 1.61% (95% confidence interval (CI) 1.53% to 1.69%) in 2007 to 2.22% (95% CI 2.13% to 2.31%) in 2017. A similar pattern was evident for males, with a lifetime risk of 1.43% (95% CI 1.36% to 1.51%) in 2007 and 2.02% (95% CI 1.93% to 2.11%) in 2017. A decline in procedures performed for loosening/lysis (from 41% in 2007 to 24% in 2017) and pain (from 14% to 9%) was evident, while infection became an increasingly common indication (from 19% in 2007 to 29% in 2017). Conclusion. Well-validated national registry data can help us understand the epidemiology of revision knee arthroplasty, including changing clinical indications. Despite a small increase over a decade, the lifetime risk of revision knee arthroplasty in Australia is low at one in 45 females and one in 50 males. These methods offer a population-level approach to quantifying revision burden that can be used for ongoing national surveillance and between-country comparisons. Cite this article: Bone Joint J 2022;104-B(5):613–619

Aims. The Exeter V40 femoral stem is the most implanted stem in the National Joint Registry (NJR) for primary total hip arthroplasty (THA). In 2004, the 44/00/125 stem was released for use in ‘cement-in-cement’ revision cases. It has, however, been used ‘off-label’ as a primary stem when patient anatomy requires a smaller stem with a 44 mm offset. We aimed to investigate survival of this implant in comparison to others in the range when used in primary THAs recorded in the NJR. Methods. We analyzed 328,737 primary THAs using the Exeter V40 stem, comprising 34.3% of the 958,869 from the start of the NJR to December 2018. Our exposure was the stem, and the outcome was all-cause construct revision. We stratified analyses into four groups: constructs using the 44/00/125 stem, those using the 44/0/150 stem, those including a 35.5/125 stem, and constructs using any other Exeter V40 stem. Results. In all 328,737 THAs using an Exeter V40 stem, the revision estimate was 2.8% (95% confidence interval (CI) 2.7 to 2.8). The 44/00/125 stem was implanted in 2,158 primary THAs, and the ten-year revision estimate was 4.9% (95% CI 3.6 to 6.8). Controlling for age, sex, year of operation, indication, and American Society of Anesthesiologists grade demonstrated an increased overall hazard of revision for constructs using the 44/00/125 stem compared to constructs using other Exeter V40 femoral stems (hazard ratio 1.8 (95% CI 1.4 to 2.3)). Conclusion. Although the revision estimate is within the National Institute for Health and Care Excellence ten-year benchmark, survivorship of constructs using the 44/00/125 stem appears to be lower than the rest of the range. Adjusted analyses will not take into account ‘confounding by indication’, e.g. patients with complex anatomy who may have a higher risk of revision. Surgeons and patients should be reassured but be aware of the observed increased revision estimate, and only use this stem when other implants are not suitable. Cite this article: Bone Joint J 2023;105-B(5):504–510

Aims. The aim of this study was to determine the prevalence of depressive and anxiety disorders prior to total hip (THA) and total knee arthroplasty (TKA) and to assess their impact on the rates of any infection, revision, or reoperation. Methods. Between January 2000 and March 2019, 21,469 primary and revision arthroplasties (10,011 THAs; 11,458 TKAs), which were undertaken in 15,504 patients at a single academic medical centre, were identified from a 27-county linked electronic medical record (EMR) system. Depressive and anxiety disorders were identified by diagnoses in the EMR or by using a natural language processing program with subsequent validation from review of the medical records. Patients with mental health diagnoses other than anxiety or depression were excluded. Results. Depressive and/or anxiety disorders were common before THA and TKA, with a prevalence of 30% in those who underwent primary THA, 33% in those who underwent revision THA, 32% in those who underwent primary TKA, and 35% in those who underwent revision TKA. The presence of depressive or anxiety disorders was associated with a significantly increased risk of any infection (primary THA, hazard ratio (HR) 1.5; revision THA, HR 1.9; primary TKA, HR 1.6; revision TKA, HR 1.8), revision (THA, HR 1.7; TKA, HR 1.6), re-revision (THA, HR 2.0; TKA, HR 1.6), and reoperation (primary THA, HR 1.6; revision THA, HR 2.2; primary TKA, HR 1.4; revision TKA, HR 1.9; p < 0.03 for all). Patients with preoperative depressive and/or anxiety disorders were significantly less likely to report “much better” joint function after primary THA (78% vs 87%) and primary TKA (86% vs 90%) compared with those without these disorders at two years postoperatively (p < 0.001 for all). Conclusion. The presence of depressive or anxiety disorders prior to primary or revision THA and TKA is common, and associated with a significantly higher risk of infection, revision, reoperation, and dissatisfaction. This topic deserves further study, and surgeons may consider mental health optimization to be of similar importance to preoperative variables such as diabetic control, prior to arthroplasty. Cite this article: Bone Joint J 2023;105-B(5):526–533

Aims. The duration of systemic antibiotic treatment following first-stage revision surgery for periprosthetic joint infection (PJI) after total hip arthroplasty (THA) is contentious. Our philosophy is to perform an aggressive debridement, and to use a high local concentration of targeted antibiotics in cement beads and systemic prophylactic antibiotics alone. The aim of this study was to assess the success of this philosophy in the management of PJI of the hip using our two-stage protocol. Methods. The study involved a retrospective review of our prospectively collected database from which we identified all patients who underwent an intended two-stage revision for PJI of the hip. All patients had a diagnosis of PJI according to the major criteria of the Musculoskeletal Infection Society (MSIS) 2013, a minimum five-year follow-up, and were assessed using the MSIS working group outcome-reporting tool. The outcomes were grouped into ‘successful’ or ‘unsuccessful’. Results. A total of 299 two-stage revision THAs in 289 patients met the inclusion criteria, of whom 258 (86%) proceeded to second-stage surgery. Their mean age was 68.1 years (28 to 92). The median follow-up was 10.7 years (interquartile range (IQR) 6.3 to 15.0). A 91% success rate was seen in those patients who underwent reimplantation, decreasing to 86% when including those who did not proceed to reimplantation. The median duration of postoperative systemic antibiotics following the first stage was five days (IQR 5 to 9). There was no significant difference in outcome between those patients who were treated with antibiotics for ≤ 48 hours (p = 0.961) or ≤ five days (p = 0.376) compared with those who were treated with longer courses. Greater success rates were seen for Gram-positive PJIs (87%) than for Gram-negative (84%) and mixed-Gram PJIs (72%; p = 0.098). Conclusion. Aggressive surgical debridement with a high local concentration of targeted antibiotics at the time of first-stage revision surgery for PJI of the hip, without prolonged systemic antibiotics, provides a high rate of success, responsible antibiotic stewardship, and reduced hospital costs. Cite this article: Bone Joint J 2023;105-B(5):511–517

Aims. In the last decade, perioperative advancements have expanded the use of outpatient primary total knee arthroplasty (TKA). Despite this, there remains limited data on expedited discharge after revision TKA. This study compared 30-day readmissions and reoperations in patients undergoing revision TKA with a hospital stay greater or less than 24 hours. The authors hypothesized that expedited discharge in select patients would not be associated with increased 30-day readmissions and reoperations. Methods. Aseptic revision TKAs in the National Surgical Quality Improvement Program database were reviewed from 2013 to 2020. TKAs were stratified by length of hospital stay (greater or less than 24 hours). Patient demographic details, medical comorbidities, American Society of Anesthesiologists (ASA) grade, operating time, components revised, 30-day readmissions, and reoperations were compared. Multivariate analysis evaluated predictors of discharge prior to 24 hours, 30-day readmission, and reoperation. Results. Of 21,610 aseptic revision TKAs evaluated, 530 were discharged within 24 hours. Short-stay patients were younger (63.1 years (49 to 78) vs 65.1 years (18 to 94)), with lower BMI (32.3 kg/m. 2. (17 to 47) vs 33.6 kg/m. 2. (19 to 54) and lower ASA grades. Diabetes, chronic obstructive pulmonary disease, hypertension, and cancer were all associated with a hospital stay over 24 hours. Single component revisions (56.8% (n = 301) vs 32.4% (n = 6,823)), and shorter mean operating time (89.7 minutes (25 to 275) vs 130.2 minutes (30 to 517)) were associated with accelerated discharge. Accelerated discharge was not associated with 30-day readmission and reoperation. Conclusion. Accelerated discharge after revision TKA did not increase short-term complications, readmissions, or reoperations. Further efforts to decrease hospital stays in this setting should be evaluated. Cite this article: Bone Joint J 2022;104-B(12):1323–1328

Aims. Registry studies on modified acetabular polyethylene (PE) liner designs are limited. We investigated the influence of standard and modified PE acetabular liner designs on the revision rate for mechanical complications in primary cementless total hip arthroplasty (THA). Methods. We analyzed 151,096 primary cementless THAs from the German Arthroplasty Registry (EPRD) between November 2012 and November 2020. Cumulative incidence of revision for mechanical complications for standard and four modified PE liners (lipped, offset, angulated/offset, and angulated) was determined using competing risk analysis at one and seven years. Confounders were investigated with a Cox proportional-hazards model. Results. Median follow-up was 868 days (interquartile range 418 to 1,364). The offset liner design reduced the risk of revision (hazard ratio (HR) 0.68 (95% confidence interval (CI) 0.50 to 0.92)), while the angulated/offset liner increased the risk of revision for mechanical failure (HR 1.81 (95% CI 1.38 to 2.36)). The cumulative incidence of revision was lowest for the offset liner at one and seven years (1.0% (95% CI 0.7 to 1.3) and 1.8% (95% CI 1.0 to 3.0)). No difference was found between standard, lipped, and angulated liner designs. Higher age at index primary THA and an Elixhauser Comorbidity Index greater than 0 increased the revision risk in the first year after surgery. Implantation of a higher proportion of a single design of liner in a hospital reduced revision risk slightly but significantly (p = 0.001). Conclusion. The use of standard acetabular component liners remains a good choice in primary uncemented THA, as most modified liner designs were not associated with a reduced risk of revision for mechanical failure. Offset liner designs were found to be beneficial and angulated/offset liner designs were associated with higher risks of revision. Cite this article: Bone Joint J 2022;104-B(7):801–810

There are many reasons why a total knee replacement (TKR) may fail and qualify for revision. Successful revision surgery depends as much on accurate assessment of the problem TKR as it does on revision implant design and surgical technique. Specific modes of failure require specific surgical solutions. Causes of failure are often presented as a list or catalogue, without a system or process for making a decision. In addition, strict definitions and consensus on modes of failure are lacking in published series and registry data. How we approach the problem TKR is an essential but neglected aspect of understanding knee replacement surgery. It must be carried out systematically, comprehensively and efficiently. Eight modes of failure are described: 1) sepsis; 2) extensor discontinuity; 3) stiffness; 4) tibial- femoral instability; 5) patellar tracking; 6) aseptic loosening and osteolysis; 7) periprosthetic fracture and 8) component breakage. A ninth ‘category’, unexplained pain is an indication for further investigation but not surgery. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):105–11

Aims. Total hip arthroplasties (THAs) are performed by surgeons at various stages in training with varying levels of supervision, but we do not know if this is safe practice with comparable outcomes to consultant-performed THA. Our aim was to examine the association between surgeon grade, the senior supervision of trainees, and the risk of revision following THA. Methods. We performed an observational study using National Joint Registry (NJR) data. We included adult patients who underwent primary THA for osteoarthritis, recorded in the NJR between 2003 and 2016. Exposures were operating surgeon grade (consultant or trainee) and whether or not trainees were directly supervised by a scrubbed consultant. Outcomes were all-cause revision and the indication for revision up to ten years. We used methods of survival analysis, adjusted for patient, operation, and healthcare setting factors. Results. We included 603,474 THAs, of which 58,137 (9.6%) procedures were performed by a trainee. There was no association between surgeon grade and all-cause revision up to ten years (crude hazard ratio (HR) 1.00 (95% confidence interval (CI) 0.94 to 1.07); p = 0.966), a finding which persisted with adjusted analysis. Fully adjusted analysis demonstrated an association between trainees operating without scrubbed consultant supervision and an increased risk of all-cause revision (HR 1.10 (95% CI 1.00 to 1.21); p = 0.045). There was an association between trainee-performed THA and revision for instability (HR 1.14 (95% CI 1.01 to 1.30); p = 0.039). However, this was not observed in adjusted models, or when trainees were supervised by a scrubbed consultant. Conclusion. Within the current training system in England and Wales, appropriately supervised trainees achieve comparable THA survival to consultants. Trainees who are supervised by a scrubbed consultant achieve superior outcomes compared to trainees who are not supervised by a scrubbed consultant, particularly in terms of revision for instability. Cite this article: Bone Joint J 2022;104-B(3):341–351

Aims. This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision. Methods. A total of 780 patients (39% male; median age 70.7 years (IQR 62.0 to 77.2)) underwent cemented TKA using the Attune Knee System) at five centres, and with the latest radiograph available for the evaluation of RLL at between six and 36 months from surgery. Univariate and multivariate logistic regression models were performed to assess associations between patient and implant-associated factors on the presence of tibial and femoral RLLs. Differences in revision risk depending on RLLs and tibial baseplate design were investigated with the log-rank test. Results. The conventional and novel Attune baseplates were used in 349 (45%) and 431 (55%) patients, respectively. At a median follow-up of 14 months (IQR 11 to 25), RLLs were present in 29% (n = 228/777) and 15% (n = 116/776) of the tibial and femoral components, respectively, and were more common in the conventional compared to the novel baseplate. The novel baseplate was independently associated with a lower incidence of tibial and femoral RLLs (both regardless of age, sex, BMI, and time to radiograph). One- and three-year revision risk was 1% (95% CI 0.4% to 1.9%)and 6% (95% CI 2.6% to 13.2%), respectively. There was no difference between baseplate design and the presence of RLLs on the the risk of revision at short-term follow-up. Conclusion. The overall incidence of RLLs, as well as the incidence of tibial and femoral RLLs, was lower with the novel compared to the conventional tibial Attune baseplate design, but higher than in the predecessor design and other commonly used TKA systems. Cite this article: Bone Joint J 2024;106-B(11):1240–1248

The custom triflange is a patient-specific implant for the treatment of severe bone loss in revision total hip arthroplasty (THA). Through a process of three-dimensional modelling and prototyping, a hydroxyapatite-coated component is created for acetabular reconstruction. There are seven level IV studies describing the clinical results of triflange components. The most common complications include dislocation and infection, although the rates of implant removal are low. Clinical results are promising given the challenging problem. We describe the design, manufacture and implantation process and review the clinical results, contrasting them to other methods of acetabular reconstruction in revision THA. Cite this article: Bone Joint J 2016;98-B(1 Suppl A):68–72

Aims. The aim of this study was to conduct a cross-sectional, observational cohort study of patients presenting for revision of a total hip, or total or unicompartmental knee arthroplasty, to understand current routes to revision surgery and explore differences in symptoms, healthcare use, reason for revision, and the revision surgery (surgical time, components, length of stay) between patients having regular follow-up and those without. Methods. Data were collected from participants and medical records for the 12 months prior to revision. Patients with previous revision, metal-on-metal articulations, or hip hemiarthroplasty were excluded. Participants were retrospectively classified as ‘Planned’ or ‘Unplanned’ revision. Multilevel regression and propensity score matching were used to compare the two groups. Results. Data were analyzed from 568 patients, recruited in 38 UK secondary care sites between October 2017 and October 2018 (43.5% male; mean (SD) age 71.86 years (9.93); 305 hips, 263 knees). No significant inclusion differences were identified between the two groups. For hip revision, time to revision > ten years (odds ratio (OR) 3.804, 95% confidence interval (CI) (1.353 to 10.694), p = 0.011), periprosthetic fracture (OR 20.309, 95% CI (4.574 to 90.179), p < 0.001), and dislocation (OR 12.953, 95% CI (4.014 to 41.794), p < 0.001), were associated with unplanned revision. For knee, there were no associations with route to revision. Revision after ten years was more likely for those who were younger at primary surgery, regardless of route to revision. No significant differences in cost outcomes, length of surgery time, and access to a health professional in the year prior to revision were found between the two groups. When periprosthetic fractures, dislocations, and infections were excluded, healthcare use was significantly higher in the unplanned revision group. Conclusion. Differences between characteristics for patients presenting for planned and unplanned revision are minimal. Although there was greater healthcare use in those having unplanned revision, it appears unlikely that routine orthopaedic review would have detected many of these issues. It may be safe to disinvest in standard follow-up provided there is rapid access to orthopaedic review. Cite this article: Bone Joint J 2022;104-B(1):59–67

Aims. Cement-in-cement revision of the femoral component represents a widely practised technique for a variety of indications in revision total hip arthroplasty. In this study, we compare the clinical and radiological outcomes of two polished tapered femoral components. Methods. From our prospectively collated database, we identified all patients undergoing cement-in-cement revision from January 2005 to January 2013 who had a minimum of two years' follow-up. All cases were performed by the senior author using either an Exeter short revision stem or the C-Stem AMT high offset No. 1 prosthesis. Patients were followed-up annually with clinical and radiological assessment. Results. A total of 97 patients matched the inclusion criteria (50 Exeter and 47 C-Stem AMT components). There were no significant differences between the patient demographic data in either group. Mean follow-up was 9.7 years. A significant improvement in Oxford Hip Score (OHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 12-item Short-Form Survey (SF-12) scores was observed in both cohorts. Leg lengths were significantly shorter in the Exeter group, with a mean of -4 mm in this cohort compared with 0 mm in the C-Stem AMT group. One patient in the Exeter group had early evidence of radiological loosening. In total, 16 patients (15%) underwent further revision of the femoral component (seven in the C-Stem AMT group and nine in the Exeter group). No femoral components were revised for aseptic loosening. There were two cases of femoral component fracture in the Exeter group. Conclusion. Our series shows promising mid-term outcomes for the cement-in-cement revision technique using either the Exeter or C-Stem AMT components. These results demonstrate that cement-in-cement revision using a double or triple taper-slip design is a safe and reliable technique when used for the correct indications. Cite this article: Bone Joint J 2021;103-B(7):1215–1221

Aims. Corticosteroid injections are often used to manage glenohumeral arthritis in patients who may be candidates for future total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (rTSA). In the conservative management of these patients, corticosteroid injections are often provided for symptomatic relief. The purpose of this study was to determine if the timing of corticosteroid injections prior to TSA or rTSA is associated with changes in rates of revision and periprosthetic joint infection (PJI) following these procedures. Methods. Data were collected from a national insurance database from January 2006 to December 2017. Patients who underwent shoulder corticosteroid injection within one year prior to ipsilateral TSA or rTSA were identified and stratified into the following cohorts: < three months, three to six months, six to nine months, and nine to 12 months from time of corticosteroid injection to TSA or rTSA. A control cohort with no corticosteroid injection within one year prior to TSA or rTSA was used for comparison. Univariate and multivariate analyses were conducted to determine the association between specific time intervals and outcomes. Results. In total, 4,252 patients were included in this study. Among those, 1,632 patients (38.4%) received corticosteroid injection(s) within one year prior to TSA or rTSA and 2,620 patients (61.6%) did not. On multivariate analysis, patients who received corticosteroid injection < three months prior to TSA or rTSA were at significantly increased risk for revision (odds ratio (OR) 2.61 (95% confidence interval (CI) 1.77 to 3.28); p < 0.001) when compared with the control cohort. However, there was no significant increase in revision risk for all other timing interval cohorts. Notably, Charlson Comorbidity Index ≥ 3 was a significant independent risk factor for all-cause revision (OR 4.00 (95% CI 1.40 to 8.92); p = 0.036). Conclusion. There is a time-dependent relationship between the preoperative timing of corticosteroid injection and the incidence of all-cause revision surgery following TSA or rTSA. This analysis suggests that an interval of at least three months should be maintained between corticosteroid injection and TSA or rTSA to minimize risks of subsequent revision surgery. Cite this article: Bone Joint J 2022;104-B(5):620–626

Aims. Femoral cement-in-cement revision is a well described technique to reduce morbidity and complications in hip revision surgery. Traditional techniques for septic revision of hip arthroplasty necessitate removal of all bone cement from the femur. In our two centres, we have been using a cement-in-cement technique, leaving the distal femoral bone cement in selected patients for septic hip revision surgery, both for single and the first of two-stage revision procedures. A prerequisite for adoption of this technique is that the surgeon considers the cement mantle to be intimately fixed to bone without an intervening membrane between cement and host bone. We aim to report our experience for this technique. Methods. We have analyzed patients undergoing this cement-in-cement technique for femoral revision in infection, and present a consecutive series of 89 patients. Follow-up was undertaken at a mean of 56.5 months (24.0 to 134.7) for the surviving cases. Results. Seven patients (7.9%) required further revision for infection. Ten patients died of causes unrelated to their infection before their two-year review (mean 5.9 months; 0.9 to 18.6). One patient was lost to follow-up at five months after surgery, and two patients died of causes unrelated to their hip shortly after their two-year review was due without attending. Of the remaining patients, 69 remained infection-free at final review. Radiological review confirms the mechanical success of the procedure as previously described in aseptic revision, and postoperative Oxford Hip Scores suggest satisfactory functional outcomes. Conclusion. In conclusion, we found that retaining a well-fixed femoral cement mantle in the presence of infection and undertaking a cement-in-cement revision was successful in 82 of the patients (92.1%) in our series of 89, both in terms of eradication of infection and component fixation. These results are comparable to other more invasive techniques and offer significant potential benefits to the patient. Cite this article: Bone Joint J 2022;104-B(2):212–220

Aims. Joint registries typically use revision of an implant as an endpoint and report survival rates after a defined number of years. However, reporting lifetime risk of revision may be more meaningful, especially in younger patients. We aimed to assess lifetime risk of revision for patients in defined age groups at the time of primary surgery. Methods. The New Zealand Joint Registry (NZJR) was used to obtain rates and causes of revision for all primary total hip arthroplasties (THAs) performed between January 1999 and December 2016. The NZJR is linked to the New Zealand Registry of Births, Deaths and Marriages to obtain complete and accurate data. Patients were stratified by age at primary surgery, and lifetime risk of revision calculated according to age, sex, and American Society of Anesthesiologists (ASA) classification. The most common causes for revision were also analyzed for each age group. Results. The overall, ten-year implant survival rate was 93.6% (95% confidence interval (CI) 93.4% to 93.8%). It was lowest in the youngest age group (46 to 50 years), rising sequentially with increasing age to 97.5% in the oldest group (90 to 95 years). Lifetime risk of revision surgery was 27.6% (95% CI 27.3% to 27.8%) in those aged 46 to 50 years, decreasing with age to 1.1% (95% CI 0.0% to 5.8%) in those aged 90 to 95 years at the time of primary surgery. Higher ASA grades were associated with an increased lifetime risk of revision across all ages. The commonest causes for revision THA were aseptic loosening, infection, periprosthetic fracture, and dislocation. Conclusion. When counselling patients preoperatively, the lifetime risk of revision may be a more meaningful and useful measure of longer-term outcome than implant survival at defined time periods. This study highlights the considerably increased likelihood of subsequent revision surgery in younger age groups. Cite this article: Bone Joint J 2021;103-B(3):479–485

Aims. This study evaluates the association between consultant and hospital volume and the risk of re-revision and 90-day mortality following first-time revision of primary hip arthroplasty for aseptic loosening. Methods. We conducted a cohort study of first-time, single-stage revision hip arthroplasties (RHAs) performed for aseptic loosening and recorded in the National Joint Registry (NJR) data for England, Wales, Northern Ireland, and the Isle of Man between 2003 and 2019. Patient identifiers were used to link records to national mortality data, and to NJR data to identify subsequent re-revision procedures. Multivariable Cox proportional hazard models with restricted cubic splines were used to define associations between volume and outcome. Results. Among 12,961 RHAs there were 513 re-revisions within two years, and 95 deaths within 90 days of surgery. The risk of re-revision was highest for a consultant’s first RHA (hazard ratio (HR) 1.56 (95% CI 1.15 to 2.12)) and remained significantly elevated for their first 24 cases (HR 1.26 (95% CI 1.00 to 1.58)). Annual consultant volumes of five/year were associated with an almost 30% greater risk of re-revision (HR 1.28 (95% CI 1.00 to 1.64)) and 80% greater risk of 90-day mortality (HR 1.81 (95% CI 1.02 to 3.21)) compared to volumes of 20/year. RHAs performed at hospitals which had cumulatively undertaken fewer than 167 RHAs were at up to 70% greater risk of re-revision (HR 1.70 (95% CI 1.12 to 2.59)), and those having undertaken fewer than 307 RHAs were at up to three times greater risk of 90-day mortality (HR 3.05 (95% CI 1.19 to 7.82)). Conclusion. This study found a significantly higher risk of re-revision and early postoperative mortality following first-time single-stage RHA for aseptic loosening when performed by lower-volume consultants and at lower-volume institutions, supporting the move towards the centralization of such cases towards higher-volume units and surgeons. Cite this article: Bone Joint J 2024;106-B(10):1050–1058

Aims. Gram-negative periprosthetic joint infection (PJI) has been poorly studied despite its rapidly increasing incidence. Treatment with one-stage revision using intra-articular (IA) infusion of antibiotics may offer a reasonable alternative with a distinct advantage of providing a means of delivering the drug in high concentrations. Carbapenems are regarded as the last line of defense against severe Gram-negative or polymicrobial infection. This study presents the results of one-stage revision using intra-articular carbapenem infusion for treating Gram-negative PJI, and analyzes the characteristics of bacteria distribution and drug sensitivity. Methods. We retrospectively reviewed 32 patients (22 hips and 11 knees) who underwent single-stage revision combined with IA carbapenem infusion between November 2013 and March 2020. The IA and intravenous (IV) carbapenem infusions were administered for a single Gram-negative infection, and IV vancomycin combined with IA carbapenems and vancomycin was applied for polymicrobial infection including Gram-negative bacteria. The bacterial community distribution, drug sensitivity, infection control rate, functional recovery, and complications were evaluated. Reinfection or death caused by PJI was regarded as a treatment failure. Results. Gram-negative PJI was mainly caused by Escherichia coli (8/34), Enterobacter cloacae (7/34), and Klebsiella pneumoniae (5/34). Seven cases (7/32) involved polymicrobial PJIs. The resistance rates of penicillin, cephalosporin, quinolones, and sulfonamides were > 10%, and all penicillin and partial cephalosporins (first and second generation) were > 30%. Of 32 cases, treatment failed to eradicate infection in only three cases (9.4%), at a mean follow-up of 55.1 months (SD 25 to 90). The mean postoperative Harris Hip Score and Hospital for Special Surgery knee score at the most recent follow-up were 81 (62 to 91) and 79 (56 to 89), respectively. One patient developed a fistula, and another presented with a local rash on an infected joint. Conclusion. The use of IA carbapenem delivered alongside one-stage revision effectively controlled Gram-negative infection and obtained acceptable clinical outcomes with few complications. Notably, first- and second-generation cephalosporins and penicillin should be administrated with caution, due to a high incidence of resistance. Cite this article: Bone Joint J 2023;105-B(3):284–293

Aims. The aim of this study was to determine the outcome of all primary total hip arthroplasties (THAs) and their subsequent revision procedures in patients aged under 50 years performed at our institution. Methods. All 1,049 primary THAs which were undertaken in 860 patients aged under 50 years between 1988 and 2018 in our tertiary care institution were included. We used cemented implants in both primary and revision surgery. Impaction bone grafting was used in patients with acetabular or femoral bone defects. Kaplan-Meier analyses were used to determine the survival of primary and revision THA with the endpoint of revision for any reason, and of revision for aseptic loosening. Results. The mean age of the patients at the time of the initial THA was 38.6 years (SD 9.3). The mean follow-up of the THA was 8.7 years (2.0 to 31.5). The rate of survival for all primary THAs, acetabular components only, and femoral components only at 20 years’ follow-up with the endpoint of revision for any reason, was 66.7% (95% confidence interval (CI) 60.5 to 72.2), 69.1% (95% CI 63.0 to 74.4), and 83.2% (95% CI 78.1 to 87.3), respectively. A total of 138 revisions were performed. The mean age at the time of revision was 48.2 years (23 to 72). Survival of all subsequent revision procedures, revised acetabular, and revised femoral components at 15 years’ follow-up with the endpoint of revision for any reason was 70.3% (95% CI 56.1 to 80.7), 69.7% (95% CI 54.3 to 80.7), and 76.2% (95% CI 57.8 to 87.4), respectively. A Girdlestone excision arthroplasty was required in six of 860 patients (0.7%). Conclusion. The long-term outcome of cemented primary and subsequent revision THA is promising in these young patients. We showed that our philosophy of using impaction bone grafting in patients with acetabular and femoral defects is a very suitable option when treating young patients. Surgeons should realize that knowledge of the outcome of subsequent revision surgery, which is inevitable in young patients, must be communicated to this group of patients prior to their initial THA. Cite this article: Bone Joint J 2022;104-B(3):368–375

Aims. This study describes the variation in the annual volumes of revision hip arthroplasty (RHA) undertaken by consultant surgeons nationally, and the rate of accrual of RHA and corresponding primary hip arthroplasty (PHA) volume for new consultants entering practice. Methods. National Joint Registry (NJR) data for England, Wales, Northern Ireland, and the Isle of Man were received for 84,816 RHAs and 818,979 PHAs recorded between April 2011 and December 2019. RHA data comprised all revision procedures, including first-time revisions of PHA and any subsequent re-revisions recorded in public and private healthcare organizations. Annual procedure volumes undertaken by the responsible consultant surgeon in the 12 months prior to every index procedure were determined. We identified a cohort of ‘new’ HA consultants who commenced practice from 2012 and describe their rate of accrual of PHA and RHA experience. Results. The median annual consultant RHA volume, averaged across all cases, was 21 (interquartile range (IQR) 11 to 34; range 0 to 181). Of 1,695 consultants submitting RHA cases within the study period, the top 20% of surgeons by annual volume performed 74.2% of total RHA case volume. More than half of all consultants who had ever undertaken a RHA maintained an annual volume of just one or fewer RHA, however, collectively contributed less than 3% of the total RHA case volume. Consultant PHA and RHA volumes were positively correlated. Lower-volume surgeons were more likely to undertake RHA for urgent indications (such as infection) as a proportion of their practice, and to do so on weekends and public holidays. Conclusion. The majority of RHAs were undertaken by higher-volume surgeons. There was considerable variation in RHA volumes by indication, day of the week, and between consultants nationally. The rate of accrual of RHA experience by new consultants is low, and has important implications for establishing an experienced RHA consultant workforce. Cite this article: Bone Joint J 2023;105-B(10):1060–1069

Aims. The aim of this study was to determine the long-term mortality rate, and to identify factors associated with this, following primary and revision knee arthroplasty (KA). Methods. Data from the Scottish Arthroplasty Project (1998 to 2019) were retrospectively analyzed. Patient mortality data were linked from the National Records of Scotland. Analyses were performed separately for the primary and revised KA cohorts. The standardized mortality ratio (SMR) with 95% confidence intervals (CIs) was calculated for the population at risk. Multivariable Cox proportional hazards were used to identify predictors and estimate relative mortality risks. Results. At a median 7.4 years (interquartile range (IQR) 4.0 to 11.6) follow-up, 27.8% of primary (n = 27,474/98,778) and 31.3% of revision (n = 2,611/8,343) KA patients had died. Both primary and revision cohorts had lower mortality rates than the general population (SMR 0.74 (95% CI 0.73 to 0.74); p < 0.001; SMR 0.83 (95% CI 0.80 to 0.86); p < 0.001, respectively), which persisted for 12 and eighteight years after surgery, respectively. Factors associated with increased risk of mortality after primary KA included male sex (hazard ratio (HR) 1.40 (95% CI 1.36 to 1.45)), increasing socioeconomic deprivation (HR 1.43 (95% CI 1.36 to 1.50)), inflammatory polyarthropathy (HR 1.79 (95% CI 1.68 to 1.90)), greater number of comorbidities (HR 1.59 (95% CI 1.51 to 1.68)), and periprosthetic joint infection (PJI) requiring revision (HR 1.92 (95% CI 1.57 to 2.36)) when adjusting for age. Similarly, male sex (HR 1.36 (95% CI 1.24 to 1.49)), increasing socioeconomic deprivation (HR 1.31 (95% CI 1.12 to 1.52)), inflammatory polyarthropathy (HR 1.24 (95% CI 1.12 to 1.37)), greater number of comorbidities (HR 1.64 (95% CI 1.33 to 2.01)), and revision for PJI (HR 1.35 (95% 1.18 to 1.55)) were independently associated with an increased risk of mortality following revision KA when adjusting for age. Conclusion. The SMR of patients undergoing primary and revision KA was lower than that of the general population and remained so for several years post-surgery. However, approximately one in four patients undergoing primary and one in three patients undergoing revision KA died within tenten years of surgery. Several patient and surgical factors, including PJI, were associated with the risk of mortality within ten years of primary and revision surgery. Cite this article: Bone Joint J 2022;104-B(1):45–52

Aims. To determine if primary cemented acetabular component geometry (long posterior wall (LPW), hooded, or offset reorientating) influences the risk of revision total hip arthroplasty (THA) for instability or loosening. Methods. The National Joint Registry (NJR) dataset was analyzed for primary THAs performed between 2003 and 2017. A cohort of 224,874 cemented acetabular components were included. The effect of acetabular component geometry on the risk of revision for instability or for loosening was investigated using log-binomial regression adjusting for age, sex, American Society of Anesthesiologists grade, indication, side, institution type, operating surgeon grade, surgical approach, polyethylene crosslinking, and prosthetic head size. A competing risk survival analysis was performed with the competing risks being revision for other indications or death. Results. The distribution of acetabular component geometries was: LPW 81.2%; hooded 18.7%; and offset reorientating 0.1%. There were 3,313 (1.5%) revision THAs performed, of which 815 (0.4%) were for instability and 838 (0.4%) were for loosening. Compared to the LPW group, the adjusted subhazard ratio of revision for instability in the hooded group was 2.31 (p < 0.001) and 4.12 (p = 0.047) in the offset reorientating group. Likewise, the subhazard ratio of revision for loosening was 2.65 (p < 0.001) in the hooded group and 13.61 (p < 0.001) in the offset reorientating group. A time-varying subhazard ratio of revision for instability (hooded vs LPW) was found, being greatest within the first three months. Conclusion. This registry-based study confirms a significantly higher risk of revision after cemented THA for instability and for loosening when a hooded or offset reorientating acetabular component is used, compared to a LPW component. Further research is required to clarify if certain patients benefit from the use of hooded or offset reorientating components, but we recommend caution when using such components in routine clinical practice. Cite this article: Bone Joint J 2021;103-B(11):1669–1677

Aims. The aim of this study was to determine if uncemented acetabular polyethylene (PE) liner geometry, and lip size, influenced the risk of revision for instability or loosening. Methods. A total of 202,511 primary total hip arthroplasties (THAs) with uncemented acetabular components were identified from the National Joint Registry (NJR) dataset between 2003 and 2017. The effect of liner geometry on the risk of revision for instability or loosening was investigated using competing risk regression analyses adjusting for age, sex, American Society of Anesthesiologists grade, indication, side, institution type, surgeon grade, surgical approach, head size, and polyethylene crosslinking. Stratified analyses by surgical approach were performed, including pairwise comparisons of liner geometries. Results. The distribution of liner geometries were neutral (39.4%; 79,822), 10° (34.5%; 69,894), 15° (21.6%; 43,722), offset reorientating (2.8%; 5705), offset neutral (0.9%; 1,767), and 20° (0.8%; 1,601). There were 690 (0.34%) revisions for instability. Compared to neutral liners, the adjusted subhazard ratios of revision for instability were: 10°, 0.64 (p < 0.001); 15°, 0.48 (p < 0.001); and offset reorientating, 1.6 (p = 0.010). No association was found with other geometries. 10° and 15° liners had a time-dependent lower risk of revision for instability within the first 1.2 years. In posterior approaches, 10° and 15° liners had a lower risk of revision for instability, with no significant difference between them. The protective effect of lipped over neutral liners was not observed in laterally approached THAs. There were 604 (0.3%) revisions for loosening, but no association between liner geometry and revision for loosening was found. Conclusion. This registry-based study confirms a lower risk of revision for instability in posterior approach THAs with 10° or 15° lipped liners compared to neutral liners, but no significant difference between these lip sizes. A higher revision risk is seen with offset reorientating liners. The benefit of lipped geometries against revision for instability was not seen in laterally approached THAs. Liner geometry does not seem to influence the risk of revision for loosening. Cite this article: Bone Joint J 2021;103-B(12):1774–1782

Aims. Uncemented mobile bearing designs in medial unicompartmental knee arthroplasty (UKA) have seen an increase over the last decade. However, there are a lack of large-scale studies comparing survivorship of these specific designs to commonly used cemented mobile and fixed bearing designs. The aim of this study was to evaluate the survivorship of these designs. Methods. A total of 21,610 medial UKAs from 2007 to 2018 were selected from the Dutch Arthroplasty Register. Multivariate Cox regression analyses were used to compare uncemented mobile bearings with cemented mobile and fixed bearings. Adjustments were made for patient and surgical factors, with their interactions being considered. Reasons and type of revision in the first two years after surgery were assessed. Results. In hospitals performing less than 100 cases per year, cemented mobile bearings reported comparable adjusted risks of revision as uncemented mobile bearings. However, in hospitals performing more than 100 cases per year, the adjusted risk of revision was higher for cemented mobile bearings compared to uncemented mobile bearings (hazard ratio 1.78 (95% confidence interval 1.34 to 2.35)). The adjusted risk of revision between cemented fixed bearing and uncemented mobile bearing was comparable, independent of annual hospital volume. In addition, 12.3% of uncemented mobile bearing, 20.3% of cemented mobile bearing, and 41.5% of uncemented fixed bearing revisions were for tibial component loosening. The figures for instability were 23.6%, 14.5% and 11.7%, respectively, and for periprosthetic fractures were 10.0%, 2.8%, and 3.5%. Bearing exchange was the type of revision in 40% of uncemented mobile bearing, 24.3% of cemented mobile bearing, and 5.3% cemented fixed bearing revisions. Conclusion. The findings of this study demonstrated improved survival with use of uncemented compared to cemented mobile bearings in medial UKA, only in those hospitals performing more than 100 cases per year. Cemented fixed bearings reported comparable survival results as uncemented mobile bearings, regardless of the annual hospital volume. The high rates of instability, periprosthetic fractures, and bearing exchange in uncemented mobile bearings emphasize the need for further research. Cite this article: Bone Joint J 2021;103-B(7):1261–1269

We undertook a retrospective cohort study to determine clinical outcomes following the revision of metal-on-metal (MoM) hip replacements for adverse reaction to metal debris (ARMD), and to identify predictors of time to revision and outcomes following revision. Between 1998 and 2012 a total of 64 MoM hips (mean age at revision of 57.8 years; 46 (72%) female; 46 (72%) hip resurfacings and 18 (28%) total hip replacements) were revised for ARMD at one specialist centre. At a mean follow-up of 4.5 years (1.0 to 14.6) from revision for ARMD there were 13 hips (20.3%) with post-operative complications and eight (12.5%) requiring re-revision. . The Kaplan–Meier five-year survival rate for ARMD revision was 87.9% (95% confidence interval 78.9 to 98.0; 19 hips at risk). Excluding re-revisions, the median absolute Oxford hip score (OHS) following ARMD revision using the percentage method (0% best outcome and 100% worst outcome) was 18.8% (interquartile range (IQR) 7.8% to 48.3%), which is equivalent to 39/48 (IQR 24.8/48 to 44.3/48) when using the modified OHS. Histopathological response did not affect time to revision for ARMD (p = 0.334) or the subsequent risk of re-revision (p = 0.879). Similarly, the presence or absence of a contralateral MoM hip bearing did not affect time to revision for ARMD (p = 0.066) or the subsequent risk of re-revision (p = 0.178). . Patients revised to MoM bearings had higher rates of re-revision (five of 16 MoM hips re-revised; p = 0.046), but those not requiring re-revision had good functional results (median absolute OHS 14.6% or 41.0/48). Short-term morbidity following revision for ARMD was comparable with previous reports. Caution should be exercised when choosing bearing surfaces for ARMD revisions. Cite this article: Bone Joint J 2014;96-B:1600–9

Aims. One-stage revision hip arthroplasty for periprosthetic joint infection (PJI) has several advantages; however, resection of the proximal femur might be necessary to achieve higher success rates. We investigated the risk factors for resection and re-revisions, and assessed complications and subsequent re-revisions. Methods. In this single-centre, case-control study, 57 patients who underwent one-stage revision arthroplasty for PJI of the hip and required resection of the proximal femur between 2009 and 2018 were identified. The control group consisted of 57 patients undergoing one-stage revision without bony resection. Logistic regression analysis was performed to identify any correlation with resection and the risk factors for re-revisions. Rates of all-causes re-revision, reinfection, and instability were compared between groups. Results. Patients who required resection of the proximal femur were found to have a higher all-cause re-revision rate (29.8% vs 10.5%; p = 0.018), largely due to reinfection (15.8% vs 0%; p = 0.003), and dislocation (8.8% vs 10.5%; p = 0.762), and showed higher rate of in-hospital wound haematoma requiring aspiration or evacuation (p = 0.013), and wound revision (p = 0.008). The use of of dual mobility components/constrained liner in the resection group was higher than that of controls (94.7% vs 36.8%; p < 0.001). The presence and removal of additional metal hardware (odds ratio (OR) = 7.2), a sinus tract (OR 4), ten years’ time interval between primary implantation and index infection (OR 3.3), and previous hip revision (OR 1.4) increased the risk of proximal femoral resection. A sinus tract (OR 9.2) and postoperative dislocation (OR 281.4) were associated with increased risk of subsequent re-revisions. Conclusion. Proximal femoral resection during one-stage revision hip arthroplasty for PJI may be required to reduce the risk of of recurrent or further infection. Patients with additional metalware needing removal or transcortical sinus tracts and chronic osteomyelitis are particularly at higher risk of needing proximal femoral excision. However, radical resection is associated with higher surgical complications and increased re-revision rates. The use of constrained acetabular liners and dual mobility components maintained an acceptable dislocation rate. These results, including identified risk factors, may aid in preoperative planning, patient consultation and consent, and intraoperative decision-making. Cite this article: Bone Joint J 2021;103-B(11):1678–1685

Aims. Periprosthetic joint infections (PJIs) with prior multiple failed surgery for reinfection represent a huge challenge for surgeons because of poor vascular supply and biofilm formation. This study aims to determine the results of single-stage revision using intra-articular antibiotic infusion in treating this condition. Methods. A retrospective analysis included 78 PJI patients (29 hips; 49 knees) who had undergone multiple prior surgical interventions. Our cohort was treated with single-stage revision using a supplementary intra-articular antibiotic infusion. Of these 78 patients, 59 had undergone more than two prior failed debridement and implant retentions, 12 patients had a failed arthroplasty resection, three hips had previously undergone failed two-stage revision, and four had a failed one-stage revision before their single-stage revision. Previous failure was defined as infection recurrence requiring surgical intervention. Besides intravenous pathogen-sensitive agents, an intra-articular infusion of vancomycin, imipenem, or voriconazole was performed postoperatively. The antibiotic solution was soaked into the joint for 24 hours for a mean of 16 days (12 to 21), then extracted before next injection. Recurrence of infection and clinical outcomes were evaluated. Results. A total of 68 patients (87.1%) were free of infection at a mean follow-up time of 85 months (24 to 133). The seven-year infection-free survival was 87.6% (95% confidence interval (CI) 79.4 to 95.8). No significant difference in infection-free survival was observed between hip and knee PJIs (91.5% (95% CI 79.9 to 100) vs 84.7% (95% CI 73.1 to 96.3); p = 0.648). The mean postoperative Harris Hip Score was 76.1 points (63.2 to 92.4) and Hospital for Special Surgery score was 78. 2 (63.2 to 92.4) at the most recent assessment. Polymicrobial and fungal infections accounted for 14.1% (11/78) and 9.0% (7/78) of all cases, respectively. Conclusion. Single-stage revision with intra-articular antibiotic infusion can provide high antibiotic concentration in synovial fluid, thereby overcoming reduced vascular supply and biofilm formation. This supplementary route of administration may be a viable option in treating PJI after multiple failed prior surgeries for reinfection. Cite this article: Bone Joint J 2022;104-B(7):867–874

Aims. The risk of mechanical failure of modular revision hip stems is frequently mentioned in the literature, but little is currently known about the actual clinical failure rates of this type of prosthesis. The current retrospective long-term analysis examines the distal and modular failure patterns of the Prevision hip stem from 18 years of clinical use. A design improvement of the modular taper was introduced in 2008, and the data could also be used to compare the original and the current design of the modular connection. Methods. We performed an analysis of the Prevision modular hip stem using the manufacturer’s vigilance database and investigated different mechanical failure patterns of the hip stem from January 2004 to December 2022. Results. Two mechanical failure patterns were identified: fractures in the area of the distal fluted profile (distal stem fracture) and failure of the modular taper (modular fracture). A failure rate of 0.07% was observed for distal stem fracture, and modular fracture rates of 1.74% for the original and 0.013% for the current taper design. Conclusion. A low risk of mechanical failure for both fracture types was observed compared to other known complications in revision hip arthroplasty. In addition, the data show that a design change did significantly reduce the risk of a modular fracture. Cite this article: Bone Joint J 2024;106-B(2):151–157

Bactericidal levels of antibiotics are difficult to achieve in infected total joint arthroplasty when intravenous antibiotics or antibiotic-loaded cement spacers are used, but intra-articular (IA) delivery of antibiotics has been effective in several studies. This paper describes a protocol for IA delivery of antibiotics in infected knee arthroplasty, and summarises the results of a pharmacokinetic study and two clinical follow-up studies of especially difficult groups: methicillin-resistant Staphylococcus aureus and failed two-stage revision. In the pharmacokinetic study, the mean synovial vancomycin peak level was 9242 (3956 to 32 150; . sd . 7608 μg/mL) among the 11 patients studied. Serum trough level ranged from 4.2 to 25.2 μg/mL (mean, 12.3 μg/mL; average of 9.6% of the joint trough value), which exceeded minimal inhibitory concentration. The success rate exceeded 95% in the two clinical groups. IA delivery of antibiotics is shown to be safe and effective, and is now the first option for treatment of infected total joint arthroplasty in our institution. Cite this article: Bone Joint J 2016;98-B(1 Suppl A):31–6

Aims. To determine mortality risk after first revision total hip arthroplasty (THA) for periprosthetic femoral fracture (PFF), and to compare this to mortality risk after primary and first revision THA for other common indications. Methods. The study cohort consisted of THAs recorded in the National Joint Registry between 2003 and 2015, linked to national mortality data. First revision THAs for PFF, infection, dislocation, and aseptic loosening were identified. We used a flexible parametric model to estimate the cumulative incidence function of death at 90 days, one year, and five years following first revision THA and primary THA, in the presence of further revision as a competing risk. Analysis covariates were age, sex, and American Society of Anesthesiologists (ASA) grade. Results. A total of 675,078 primary and 74,223 first revision THAs were included (of which 6,131 were performed for PFF). Following revision for PFF, mortality ranged from 9% at 90 days, 21% at one year, and 60% at five years in the highest risk group (males, ≥ 75 years, ASA ≥ 3) to 0.6%, 1.4%, and 5.5%, respectively, for the lowest risk group (females, < 75 years, ASA ≤ 2). Mortality was greater in all groups following first revision THA for PFF than for primary THA. Compared to mortality risk after first revision THA for infection, dislocation, or aseptic loosening, revision for PFF was associated with higher five-year mortality in all groups except males < 75 years with an ASA ≤ 2. Conclusion. Mortality risk after revision THA for PFF is high, reaching 60% at five years in the highest risk patient group. In comparison to other common indications for revision, PFF demonstrated the highest overall risk of mortality at five years. These estimates can be used in the surgical decision-making process and when counselling patients and carers regarding surgical risk. Cite this article: Bone Joint J 2020;102-B(12):1670–1674

Aims. The purpose of this study was to evaluate unexpected positive cultures in total hip arthroplasty (THA) revisions for presumed aseptic loosening, to assess the prevalence of low-grade infection using two definition criteria, and to analyze its impact on implant survival after revision. Methods. A total of 274 THA revisions performed for presumed aseptic loosening from 2012 to 2016 were reviewed. In addition to obtaining intraoperative tissue cultures from all patients, synovial and sonication fluid samples of the removed implant were obtained in 215 cases (79%) and 101 cases (37%), respectively. Histopathological analysis was performed in 250 cases (91%). Patients were classified as having low-grade infections according to institutional criteria and Musculoskeletal Infection Society (MSIS) International Consensus Meeting (ICM) 2013 criteria. Low-grade infections according to institutional criteria were treated with targeted antibiotics for six weeks postoperatively. Implant failure was defined as the need for re-revision resulting from periprosthetic joint infection (PJI) and aseptic reasons. The mean follow-up was 68 months (26 to 95). Results. Unexpected positive intraoperative samples were found in 77 revisions (28%). Low-grade infection was diagnosed in 36 cases (13%) using institutional criteria and in nine cases (3%) using MSIS ICM 2013 criteria. In all, 41 patients (15%) had single specimen growth of a low-virulent pathogen and were deemed contaminated. Coagulase-negative Staphylococcus and anaerobes were the most commonly isolated bacteria. Implant failure for PJI was higher in revisions with presumed contaminants (5/41, 12%) compared to those with low-grade infections (2/36, 6%) and those with negative samples (5/197, 3%) (p = 0.021). The rate of all-cause re-revision was similar in patients diagnosed with low-grade infections (5/36, 14%) and those with presumed contaminants (6/41, 15%) and negative samples (21/197, 11%) (p = 0.699). Conclusion. Our findings suggest that the presumption of culture contamination in aseptic revision hip arthroplasty may increase the detection of PJI. In this cohort, the presence of low-grade infection did not increase the risk of re-revision. Further studies are needed to assess the relevance of single specimen growth and the benefits of specific postoperative antibiotic regimens. Cite this article: Bone Joint J 2021;103-B(6):1070–1077

Aims. The aims of this study were to determine the success of a reconstruction algorithm used in major acetabular bone loss, and to further define the indications for custom-made implants in major acetabular bone loss. Methods. We reviewed a consecutive series of Paprosky type III acetabular defects treated according to a reconstruction algorithm. IIIA defects were planned to use a superior augment and hemispherical acetabular component. IIIB defects were planned to receive either a hemispherical acetabular component plus augments, a cup-cage reconstruction, or a custom-made implant. We used national digital health records and registry reports to identify any reoperation or re-revision procedure and Oxford Hip Score (OHS) for patient-reported outcomes. Implant survival was determined via Kaplan-Meier analysis. Results. A total of 105 procedures were carried out in 100 patients (five bilateral) with a mean age of 73 years (42 to 94). In the IIIA defects treated, 72.0% (36 of 50) required a porous metal augment; the remaining 14 patients were treated with a hemispherical acetabular component alone. In the IIIB defects, 63.6% (35 of 55) underwent reconstruction as planned with 20 patients who actually required a hemispherical acetabular component alone. At mean follow-up of 7.6 years, survival was 94.3% (95% confidence interval 97.4 to 88.1) for all-cause revision and the overall dislocation rate was 3.8% (4 of 105). There was no difference observed in survival between type IIIA and type IIIB defects and whether a hemispherical implant alone was used for the reconstruction or not. The mean gain in OHS was 16 points. Custom-made implants were only used in six cases, in patients with either a mega-defect in which the anteroposterior diameter > 80 mm, complex pelvic discontinuity, and massive bone loss in a small pelvis. Conclusion. Our findings suggest that a reconstruction algorithm can provide a successful approach to reconstruction in major acetabular bone loss. The use of custom implants has been defined in this series and accounts for < 5% of cases. Cite this article: Bone Joint J 2024;106-B(5 Supple B):47–53

Aims. Revision total hip arthroplasty in patients with Vancouver type B3 fractures with Paprosky type IIIA, IIIB, and IV femoral defects are difficult to treat. One option for Paprovsky type IIIB and IV defects involves modular cementless, tapered, revision femoral components in conjunction with distal interlocking screws. The aim of this study was to analyze the rate of reoperations and complications and union of the fracture, subsidence of the stem, mortality, and the clinical outcomes in these patients. Methods. A total of 46 femoral components in patients with Vancouver B3 fractures (23 with Paprosky type IIIA, 19 with type IIIB, and four with type IV defects) in 46 patients were revised with a transfemoral approach using a modular, tapered, cementless revision Revitan curved femoral component with distal cone-in-cone fixation and prospectively followed for a mean of 48.8 months (SD 23.9; 24 to 112). The mean age of the patients was 80.4 years (66 to 100). Additional distal interlocking was also used in 23 fractures in which distal cone-in-cone fixation in the isthmus was < 3 cm. Results. One patient (2.2%) died during the first postoperative year. After six months, 43 patients (93.5%) had osseous, and three had fibrous consolidation of the fracture and the bony flap, 42 (91.3%) had bony ingrowth and four had stable fibrous fixation of the stem. No patient had radiolucency around the interlocking screws and no screw broke. One patient had non-progressive subsidence and two had a dislocation. The mean Harris Hip Score increased from of 57.8 points (SD 7.9) three months postoperatively to 76.1 points (SD 10.7) 24 months postoperatively. Conclusion. The 2° tapered, fluted revision femoral component with distal cone-in-cone-fixation, combined with additional distal interlocking in patients with bony deficiency at the isthmus, led to reproducibly good results in patients with a Vancouver B3 fracture and Paprosky type IIIA, IIIB, and IV defects with regard to union of the fracture, subsidence or loosening of the stem, and clinical outcomes. Cite this article: Bone Joint J 2024;106-B(4):344–351

Previous studies of failure mechanisms leading to revision total knee replacement (TKR) performed between 1986 and 2000 determined that many failed early, with a disproportionate amount accounted for by infection and implant-associated factors including wear, loosening and instability. Since then, efforts have been made to improve implant performance and instruct surgeons in best practice. Recently our centre participated in a multi-centre evaluation of 844 revision TKRs from 2010 to 2011. The purpose was to report a detailed analysis of failure mechanisms over time and to see if failure modes have changed over the past 10 to 15 years. Aseptic loosening was the predominant mechanism of failure (31.2%), followed by instability (18.7%), infection (16.2%), polyethylene wear (10.0%), arthrofibrosis (6.9%) and malalignment (6.6%). The mean time to failure was 5.9 years (ten days to 31 years), 35.3% of all revisions occurred at less than two years, and 60.2% in the first five years. With improvements in implant and polyethylene manufacture, polyethylene wear is no longer a leading cause of failure. Early mechanisms of failure are primarily technical errors. In addition to improving implant longevity, industry and surgeons must work together to decrease these technical errors. All reports on failure of TKR contain patients with unexplained pain who not infrequently have unmet expectations. Surgeons must work to achieve realistic patient expectations pre-operatively, and therefore, improve patient satisfaction post-operatively. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):101–4

Aims. This study aimed to compare the effect of antibiotic-loaded bone cement (ALBC) versus plain bone cement (PBC) on revision rates for periprosthetic joint infection (PJI) and all-cause revisions following primary elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods. MEDLINE, Embase, Web of Science, and Cochrane databases were systematically searched for studies comparing ALBC versus PBC, reporting on revision rates for PJI or all-cause revision following primary elective THA or TKA. A random-effects meta-analysis was performed. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO ID CRD42018107691). Results. Nine studies and one registry report were identified, enabling the inclusion of 371,977 THA and 671,246 TKA. Pooled analysis for THA demonstrated ALBC was protective against revision for PJI compared with PBC (relative risk (RR) 0.66, 95% confidence interval (CI) 0.56 to 0.77; p < 0.001), however, no differences were seen for all-cause revision rate (RR 0.62, 95% CI 0.35 to 1.09; p = 0.100). For TKA, there were no significant differences in revision rates for PJI or all causes between ALBC and PBC (RR 0.92, 95% CI 0.59 to 1.45; p = 0.730, and RR 0.73, 95% CI 0.53 to 1.02; p = 0.060, respectively). Conclusion. ALBC demonstrated a protective effect against revision for PJI compared with PBC in THA with no difference in all-cause revisions. No differences in revision rates for PJI and all-cause revision between ALBC and PBC for TKA were observed. Cite this article: Bone Joint J 2021;103-B(1):7–15

Aims. Aseptic loosening of the tibial component is a frequent cause of failure in primary total knee arthroplasty (TKA). Management options include an isolated tibial revision or full component revision. A full component revision is frequently selected by surgeons unfamiliar with the existing implant or who simply wish to “start again”. This option adds morbidity compared with an isolated tibial revision. While isolated tibial revision has a lower morbidity, it is technically more challenging due to difficulties with exposure and maintaining prosthetic stability. This study was designed to compare these two reconstructive options. Methods. Patients undergoing revision TKA for isolated aseptic tibial loosening between 2012 and 2017 were identified. Those with revision implants or revised for infection, instability, osteolysis, or femoral component loosening were excluded. A total of 164 patients were included; 88 had an isolated tibial revision and 76 had revision of both components despite only having a loose tibial component. The demographics and clinical and radiological outcomes were recorded. Results. The patient demographics were statistically similar in the two cohorts. The median follow-up was 3.5 years (interquartile range (IQR) 1 to 12.5). Supplementary femoral metaphyseal fixation was required in five patients in the full revision cohort. There was a higher incidence of radiological tibial loosening in the full component revision cohort at the final follow-up (8 (10.5%) vs 5 (5.7%); p = 0.269). Three patients in the full component revision cohort developed instability while only one in the isolated tibial cohort did. Three patients in the full revision cohort developed a flexion contracture greater than 5° while none in the isolated tibial cohort did. Conclusion. Isolated tibial revision for aseptic tibial loosening has statistically similar clinical and radiological outcomes at a median follow-up of 3.5 years, when compared with full component revision. Substantial bone loss can occur when removing a well-fixed femoral component necessitating a cone or sleeve. Femoral component revision for isolated tibial loosening can frequently be avoided provided adequate ligamentous stability can be obtained. Cite this article: Bone Joint J 2020;102-B(6 Supple A):123–128

Aims. The rate of dislocation when traditional single bearing implants are used in revision total hip arthroplasty (THA) has been reported to be between 8% and 10%. The use of dual mobility bearings can reduce this risk to between 0.5% and 2%. Dual mobility bearings are more expensive, and it is not clear if the additional clinical benefits constitute value for money for the payers. We aimed to estimate the cost-effectiveness of dual mobility compared with single bearings for patients undergoing revision THA. Methods. We developed a Markov model to estimate the expected cost and benefits of dual mobility compared with single bearing implants in patients undergoing revision THA. The rates of revision and further revision were calculated from the National Joint Registry of England and Wales, while rates of transition from one health state to another were estimated from the literature, and the data were stratified by sex and age. Implant and healthcare costs were estimated from local procurement prices and national tariffs. Quality-adjusted life-years (QALYs) were calculated using published utility estimates for patients undergoing THA. Results. At a minimum five-year follow-up, the use of dual mobility was cost-effective with an estimated incremental cost-effectiveness ratio (ICER) of between £3,006 and £18,745/QALY for patients aged < 55 years and between 64 and 75 years, respectively. For those aged > 75 years dual mobility was only cost-effective if the timeline was beyond seven years. The use of dual mobility bearings was cost-saving for patients aged < 75 years and cost-effective for those aged > 75 years if the time horizon was beyond ten years. Conclusion. The use of dual mobility bearings is cost-effective compared with single bearings in patients undergoing revision THA. The younger the patient is, the more likely it is that a dual mobility bearing can be more cost-effective and even cost-saving. The results are affected by the time horizon and cost of bearings for those aged > 75 years. For patients aged > 75 years, the surgeon must decide whether the use of a dual mobility bearing is a viable economic and clinical option. Cite this article: Bone Joint J 2020;102-B(9):1128–1135

Aims. The aim of this study was to investigate the differences in 30-day outcomes between patients undergoing revision for an infected total hip arthroplasty (THA) compared with an aseptic revision THA. Patients and Methods. This was a retrospective review of prospectively collected data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database, between 2012 and 2017, using Current Procedural Terminology (CPT) codes for patients undergoing a revision THA (27134, 27137, 27138). International Classification of Diseases Ninth Revision/Tenth Revision (ICD-9-CM, ICD-10-CM) diagnosis codes for infection of an implant or device were used to identify patients undergoing an infected revision THA. CPT-27132 coupled with ICD-9-CM/ICD-10-CM codes for infection were used to identify patients undergoing a two-stage revision. A total of 13 556 patients were included; 1606 (11.8%) underwent a revision THA due to infection and there were 11 951 (88.2%) aseptic revisions. Results. Patients undergoing an infected revision had a significantly greater length of stay of more than three days (p < 0.001), higher odds of any 30-day complication (p < 0.001), readmission within 30 days (p < 0.001), 30-day reoperations (p < 0.001), and discharge to a destination other than the patient’s home (p < 0.001). Conclusion. The findings suggest the need for enhanced risk adjustment based on the indication of revision THA prior to setting prices in bundled payment models of total joint arthroplasty. This risk adjustment should be used to reduce the chance of financial disincentives in clinical practice. Cite this article: Bone Joint J 2019;101-B:547–551

Aims. It has been hypothesized that a unicompartmental knee arthroplasty (UKA) is more likely to be revised than a total knee arthroplasty (TKA) because conversion surgery to a primary TKA is a less complicated procedure. The purpose of this study was to determine if there is a lower threshold for revising a UKA compared with TKA based on Oxford Knee Scores (OKSs) and range of movement (ROM) at the time of revision. Methods. We retrospectively reviewed 619 aseptic revision cases performed between December 1998 and October 2018. This included 138 UKAs that underwent conversion to TKA and 481 initial TKA revisions. Age, body mass index (BMI), time in situ, OKS, and ROM were available for all patients. Results. There were no differences between the two groups based on demographics or time to revision. The top reasons for aseptic TKA revision were loosening in 212 (44%), instability in 88 (18%), and wear in 69 (14%). UKA revision diagnoses were primarily for loosening in 50 (36%), progression of osteoarthritis (OA) in 50 (36%), and wear in 17 (12%). Out of a maximum 48 points, the mean OKS of the UKAs before revision was 23 (SD 9.3), which was significantly higher than the TKAs at 19.2 (SD 9.8; p < 0.001). UKA patients scored statistically better on nine of the 12 individual OKS questions. The UKA cases also had a larger pre-revision mean ROM (114°, SD 14.3°) than TKAs (98°, SD 25°) ; p < 0.001). Conclusion. At revision, the mean UKA OKSs and ROM were significantly better than those of TKA cases. This study suggests that at our institution there is a difference in preoperative OKS between UKA and TKA at the time of revision, demonstrating a revision bias. Cite this article: Bone Joint J 2020;102-B(6 Supple A):91–95

Aims. To establish our early clinical results of a new total knee arthroplasty (TKA) tibial component introduced in 2013 and compare it to other designs in use at our hospital during the same period. Methods. This is a retrospective study of 166 (154 patients) consecutive cemented, fixed bearing, posterior-stabilized (PS) TKAs (ATTUNE) at one hospital performed by five surgeons. These were compared with a reference cohort of 511 knees (470 patients) of other designs (seven manufacturers) performed at the same hospital by the same surgeons. There were no significant differences in age, sex, BMI, or follow-up times between the two cohorts. The primary outcome was revision performed or pending. Results. In total, 19 (11.5%) ATTUNE study TKAs have been revised at a mean 30.3 months (SD 15), and loosening of the tibial component was seen in 17 of these (90%). Revision is pending in 12 (7%) knees. There was no difference between the 31 knees revised or with revision pending and the remaining 135 study knees in terms of patient characteristics, type of bone cement (p = 0.988), or individual surgeon (p = 0.550). In the reference cohort, there were significantly fewer knees revised (n = 13, 2.6%) and with revision pending (n = 8, 1.5%) (both p < 0.001), and only two had loosening of the tibial component as the reason for revision. Conclusion. This new TKA design had an unexpectedly high early rate of revision compared with our reference cohort of TKAs. Debonding of the tibial component was the most common reason for failure. Additional longer-term follow-up studies of this specific component and techniques for implantation are warranted. The version of the ATTUNE tibial component implanted in this study has undergone modifications by the manufacturer. Cite this article: Bone Joint J 2021;103-B(6 Supple A):137–144

Aims. To assess the effect of age on clinical outcome and revision rates in patients who underwent total ankle arthroplasty (TAA) for end-stage ankle osteoarthritis (OA). Methods. A consecutive series of 811 ankles (789 patients) that underwent TAA between May 2003 and December 2013 were enrolled. The influence of age on clinical outcome, including the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, and pain according to the visual analogue scale (VAS) was assessed. In addition, the risk for revision surgery that includes soft tissue procedures, periarticular arthrodeses/osteotomies, ankle joint debridement, and/or inlay exchange (defined as minor revision), as well as the risk for revision surgery necessitating the exchange of any of the metallic components or removal of implant followed by ankle/hindfoot fusion (defined as major revision) was calculated. Results. A significant improvement in the AOFAS hindfoot score and pain relief between the preoperative assessment and the last follow-up was evident. Age had a positive effect on pain relief. The risk for a minor or major revision was 28.7 % at the mean follow-up of 5.4 years and 11.0 % at a mean follow-up of 6.9 years respectively. The hazard of revision was not affected by age. Conclusion. The clinical outcome, as well as the probability for revision surgery following TAA, is comparable between younger and older patients. The overall revision rate of the Hintegra total ankle is comparable with other three component designs. TAA should no longer be reserved for low demand elderly patients, but should also be recognized as a viable option for active patients of younger age. Cite this article: Bone Joint J 2020;102-B(7):925–932

Aims. It has previously been shown that higher-volume hospitals have better outcomes following revision total knee arthroplasty (rTKA). We were unable to identify any studies which investigated the effect of surgeon volume on the outcome of rTKA. We sought to investigate whether patients of high-volume (HV) rTKA surgeons have better outcomes following this procedure compared with those of low-volume (LV) surgeons. Methods. This retrospective study involved patients who underwent aseptic unilateral rTKA between January 2016 and March 2019, using the database of a large urban academic medical centre. Surgeons who performed ≥ 19 aseptic rTKAs per year during the study period were considered HV and those who performed < 19 per year were considered LV. Demographic characteristics, surgical factors, and postoperative outcomes were compared between the two groups. Results. A total of 308 rTKAs were identified, 132 performed by HV surgeons and 176 by 22 LV surgeons. The LV group had a significantly greater proportion of non-smokers (59.8% vs 49.2%; p = 0.029). For all types of revision, HV surgeons had significantly shorter mean operating times by 17.75 minutes (p = 0.007). For the 169 full revisions (85 HV, 84 LV), HV surgeons had significantly shorter operating times (131.12 (SD 33.78) vs 171.65 (SD 49.88) minutes; p < 0.001), significantly lower re-revision rates (7.1% vs 19.0%; p = 0.023) and significantly fewer re-revisions (0.07 (SD 0.26) vs 0.29 (SD 0.74); p = 0.017). Conclusion. Patients of HV rTKA surgeons have better outcomes following full rTKA. These findings support the development of revision teams within arthroplasty centres of excellence to offer patients the best possible outcomes following rTKA. Cite this article: Bone Joint J 2021;103-B(6 Supple A):131–136

Aims. To compare rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications), and compare these with primary arthroplasty and re-revision arthroplasty. Methods. Patients undergoing primary knee arthroplasty were identified in the national Hospital Episode Statistics (HES) between 1 April 1997 to 31 March 2017. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes, including infection (undergoing surgery), pulmonary embolism, myocardial infarction, and stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications (e.g. loosening, instability, wear) were included in the elective indications cohort. Results. A total of 939,021 primary knee arthroplasty procedures were included (939,021 patients), of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% confidence interval (CI) 0.37 to 0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44 to 0.47). Revision arthroplasty for infection was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75 to 2.35; odds ratio (OR) 3.54; 95% CI 2.81 to 4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94 to 6.82; OR 6.23; 95% CI 4.39 to 8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. Conclusion. Patients undergoing revision arthroplasty for urgent indications (infection or fracture) are at higher risk of mortality and serious adverse events in comparison to primary knee arthroplasty and revision arthroplasty for elective indications. These findings will be important for patient consent and shared decision-making and should inform service design for this patient cohort. Cite this article: Bone Joint J 2021;103-B(10):1578–1585

Aims. To estimate the measurement properties for the Oxford Knee Score (OKS) in patients undergoing revision knee arthroplasty (responsiveness, minimal detectable change (MDC-90), minimal important change (MIC), minimal important difference (MID), internal consistency, construct validity, and interpretability). Methods. Secondary data analysis was performed for 10,727 patients undergoing revision knee arthroplasty between 2013 to 2019 using a UK national patient-reported outcome measure (PROM) dataset. Outcome data were collected before revision and at six months postoperatively, using the OKS and EuroQol five-dimension score (EQ-5D). Measurement properties were assessed according to COnsensus-based Standards for the selection of health status Measurement Instruments (COSMIN) guidelines. Results. A total of 9,219 patients had complete outcome data. Mean preoperative OKS was 16.7 points (SD 8.1), mean postoperative OKS 29.1 (SD 11.4), and mean change in OKS + 12.5 (SD 10.7). Median preoperative EQ-5D index was 0.260 (interquartile range (IQR) 0.055 to 0.691), median postoperative EQ-5D index 0.691 (IQR 0.516 to 0.796), and median change in EQ-5D index + 0.240 (IQR 0.000 to 0.567). Internal consistency was good with Cronbach’s α 0.88 (baseline) and 0.94 (post-revision). Construct validity found a high correlation of OKS total score with EQ-5D index (r = 0.76 (baseline), r = 0.83 (post-revision), p < 0.001). The OKS was responsive with standardized effect size (SES) 1.54 (95% confidence interval (CI) 1.51 to 1.57), compared to SES 0.83 (0.81 to 0.86) for the EQ-5D index. The MIC for the OKS was 7.5 points (95% CI 5.5 to 8.5) based on the optimal cut-off with specificity 0.72, sensitivity 0.60, and area under the curve 0.66. The MID for the OKS was 5.2 points. The MDC-90 was 3.9 points. The OKS did not demonstrate significant floor or ceiling effects. Conclusion. This study found that the OKS was a useful and valid instrument for assessment of outcome following revision knee arthroplasty. The OKS was responsive to change and demonstrated good measurement properties. Cite this article: Bone Joint J 2021;103-B(4):627–634

We analysed the results of different strategies in the revision of primary uncemented acetabular components reported to the Norwegian Arthroplasty Register. The aim was to compare the risk of further acetabular revision after isolated liner exchange and complete component revision. The results of exchanging well-fixed components were also compared with those of exchanging loose acetabular components. The period studied was between September 1987 and April 2005. The following groups were compared: group 1, exchange of liner only in 318 hips; group 2, exchange of well-fixed components in 398; and group 3, exchange of loose components in 933. We found that the risk of a further cup revision was lower after revision of well-fixed components (relative risk from a Cox model (RR) = 0.56, 95% confidence interval 0.37% to 0.87%) and loose components (RR = 0.56, 95% confidence interval 0.39% to 0.80%), compared with exchange of the liner in isolation. The most frequent reason for a further acetabular revision was dislocation, accounting for 61 (28%) of the re-revisions. Other reasons for further revision included pain in 27 (12%), loosening in 24 (11%) and infection in 20 (9%). Re-revisions because of pain were less frequent when complete component (fixed or loose) revision was undertaken compared with isolated exchange of the liner (RR = 0.20 (95% confidence interval 0.06% to 0.65%) and RR = 0.10 (95% confidence interval 0.03% to 0.30%), respectively). The risk of further acetabular revision for infection, however, did not differ between the groups. In this study, exchange of the liner only had a higher risk of further cup revision than revision of the complete acetabular component. Our results suggest that the threshold for revising well-fixed components in the case of liner wear and osteolysis should be lowered

Aims. Currently, the US Center for Medicaid and Medicare Services (CMS) has been testing bundled payments for revision total joint arthroplasty (TJA) through the Bundled Payment for Care Improvement (BPCI) programme. Under the BPCI, bundled payments for revision TJAs are defined on the basis of diagnosis-related groups (DRGs). However, these DRG-based bundled payment models may not be adequate to account appropriately for the varying case-complexity seen in revision TJAs. Methods. The 2008-2014 Medicare 5% Standard Analytical Files (SAF5) were used to identify patients undergoing revision TJA under DRG codes 466, 467, or 468. Generalized linear regression models were built to assess the independent marginal cost-impact of patient, procedural, and geographic characteristics on 90-day costs. Results. A total of 9,263 patients (DRG-466 = 838, DRG-467 = 4,573, and DRG-468 = 3,842) undergoing revision TJA from 2008 to 2014 were included in the study. Undergoing revision for a dislocation (+$1,221), periprosthetic fracture (+$4,454), and prosthetic joint infection (+$5,268) were associated with higher 90-day costs. Among comorbidities, malnutrition (+$10,927), chronic liver disease (+$3,894), congestive heart failure (+$3,292), anaemia (+$3,149), and coagulopathy (+$2,997) had the highest marginal cost-increase. The five US states with the highest 90-day costs were Alaska (+$14,751), Maryland (+$13,343), New York (+$7,428), Nevada (+$6,775), and California (+$6,731). Conclusion. Under the proposed DRG-based bundled payment methodology, surgeons would be reimbursed the same amount of money for revision TJAs, regardless of the indication (periprosthetic fracture, prosthetic joint infection, mechanical loosening) and/or patient complexity. Cite this article: Bone Joint J 2020;102-B(7):959–964

Aims. The aim of this study was to investigate whether the use of antibiotic-loaded bone cement influenced the risk of revision surgery after primary total hip arthroplasty (THA) for osteoarthritis. Methods. The study involved data collected by the National Joint Registry (NJR) for England and Wales, Northern Ireland and the Isle of Man between 1 September 2005 and 31 August 2017. Cox proportional hazards were used to investigate the association between use of antibiotic-loaded bone cement and the risk of revision due to prosthetic joint infection (PJI), with adjustments made for the year of the initial procedure, age at the time of surgery, sex, American Society of Anesthesiologists (ASA) grade, head size, and body mass index (BMI). We looked also at the association between use of antibiotic-loaded bone cement and the risk of revision due to aseptic loosening or osteolysis. Results. The cohort included 418,857 THAs of whom 397,896 had received antibiotic-loaded bone cement and 20,961 plain cement. After adjusting for putative confounding factors, the risk of revision for PJI was lower in those in whom antibiotic-loaded bone cement was used (hazard ration (HR) 0.79; 95% confidence interval (CI) 0.64 to 0.98). There was also a protective effect on the risk of revision due to aseptic loosening or osteolysis, in the period of > 4.1 years after primary THA, HR 0.57, 95% CI 0.45, 0.72. Conclusion. Within the limits of registry analysis, this study showed an association between the use of antibiotic-loaded bone cement and lower rates of revision due to PJI. The findings support the continued use of antibiotic-loaded bone cement in cemented THA. Cite this article: Bone Joint J 2020;102-B(8):997–1002

Aims. Dislocation remains a significant complication after total hip arthroplasty (THA), being the third leading indication for revision. We present a series of acetabular revision using a dual mobility cup (DMC) and compare this with our previous series using the posterior lip augmentation device (PLAD). Methods. A retrospective review of patients treated with either a DMC or PLAD for dislocation in patients with a Charnley THA was performed. They were identified using electronic patient records (EPR). EPR data and radiographs were evaluated to determine operating time, length of stay, and the incidence of complications and recurrent dislocation postoperatively. Results. A total of 28 patients underwent revision using a DMC for dislocation following Charnley THA between 2013 and 2017. The rate of recurrent dislocation and overall complications were compared with those of a previous series of 54 patients who underwent revision for dislocation using a PLAD, between 2007 and 2013. There was no statistically significant difference in the mean distribution of sex or age between the groups. The mean operating time was 71 mins (45 to 113) for DMCs and 43 mins (21 to 84) for PLADs (p = 0.001). There were no redislocations or revisions in the DMC group at a mean follow-up of 55 months (21 to 76), compared with our previous series of PLAD which had a redislocation rate of 16% (n = 9) and an overall revision rate of 25% (n = 14, p = 0.001) at a mean follow-up of 86 months (45 to 128). Conclusion. These results indicate that DMC outperforms PLAD as a treatment for dislocation in patients with a Charnley THA. This should therefore be the preferred form of treatment for these patients despite a slightly longer operating time. Work is currently ongoing to review outcomes of DMC over a longer follow-up period. PLAD should be used with caution in this patient group with preference given to acetabular revision to DMC. Cite this article: Bone Joint J 2020;102-B(4):423–425

Aims. We evaluated a large database with mechanical failure of a single uncemented modular femoral component, used in revision hip arthroplasty, as the end point and compared them to a control group treated with the same implant. Patient- and implant-specific risk factors for implant failure were analyzed. . Methods. All cases of a fractured uncemented modular revision femoral component from one manufacturer until April 2017 were identified and the total number of implants sold until April 2017 was used to calculate the fracture rate. The manufacturer provided data on patient demographics, time to failure, and implant details for all notified fractured devices. Patient- and implant-specific risk factors were evaluated using a logistic regression model with multiple imputations and compared to data from a previously published reference group, where no fractures had been observed. The results of a retrieval analysis of the fractured implants, performed by the manufacturer, were available for evaluation. Results. There were 113 recorded cases with fracture at the modular junction, resulting in a calculated fracture rate of 0.30% (113/37,600). The fracture rate of the implant without signs of improper use was 0.11% (41/37,600). In 79% (89/113) of cases with a failed implant, either a lateralized (high offset) neck segment, an extralong head, or the combination of both were used. Logistic regression analysis revealed male sex, high body mass index (BMI), straight component design, and small neck segments were significant risk factors for failure. Investigation of the implants (76/113) showed at least one sign of improper use in 72 cases. Conclusion. Implant failure at the modular junction is associated with patient- and implant-specific risk factors as well as technical errors during implantation. Whenever possible, the use of short and lateralized neck segments should be avoided with this revision system. Implantation instructions and contraindications need to be adhered to and respected. Cite this article: Bone Joint J 2020;102-B(5):573–579

Aims. We investigated the long-term performance of the Tripolar Trident acetabular component used for recurrent dislocation in revision total hip arthroplasty. We assessed: 1) rate of re-dislocation; 2) incidence of complications requiring re-operation; and 3) Western Ontario and McMaster Universities osteoarthritis index (WOMAC) pain and functional scores. Patients and Methods. We retrospectively identified 111 patients who had 113 revision tripolar constrained liners between 1994 and 2008. All patients had undergone revision hip arthroplasty before the constrained liner was used: 13 after the first revision, 17 after the second, 38 after the third, and 45 after more than three revisions. A total of 75 hips (73 patients) were treated with Tripolar liners due to recurrent instability with abductor deficiency, In addition, six patients had associated cerebral palsy, four had poliomyelitis, two had multiple sclerosis, two had spina bifida, two had spondyloepiphyseal dysplasia, one had previous reversal of an arthrodesis, and 21 had proximal femoral replacements. The mean age of patients at time of Tripolar insertions was 72 years (53 to 89); there were 69 female patients (two bilateral) and 42 male patients. All patients were followed up for a mean of 15 years (10 to 24). Overall, 55 patients (57 hips) died between April 2011 and February 2018, at a mean of 167 months (122 to 217) following their tripolar liner implantation. We extracted demographics, implant data, rate of dislocations, and incidence of other complications. Results. At ten years, the Kaplan–Meier survivorship for dislocation was 95.6% (95% confidence interval (CI) 90 to 98), with 101 patients at risk. At 20 years, the survivorship for dislocation was 90.6% (95% CI 81.0 to 95.5), with one patient at risk. Eight patients (7.2%) had a dislocation of their constrained liners. At ten years, the survival to any event was 89.4% (95% CI 82 to 93.8), with 96 patients at risk. At 20 years, the survival to any event was 82.5% (95% CI 71.9 to 89.3), with one patient at risk. Five hips (4.4%) had deep infection. Two patients (1.8%) developed dissociated constraining rings with pain but without dislocation, which required re-operation. Two patients (1.8%) had periprosthetic femoral fractures, without dislocation, that were treated by revision stems along with exchange of the well-functioning constrained liners. Conclusion. Constrained tripolar liners used at revision hip arthroplasty provided favourable results in the long term for treatment of recurrent dislocation and for patients at high risk of dislocation. Cite this article: Bone Joint J 2019;101-B(6 Supple B):123–126

Aims. In the absence of an identified organism, single-stage revision is contraindicated in prosthetic joint infection (PJI). However, no studies have examined the use of intra-articular antibiotics in combination with single-stage revision in these cases. In this study, we present the results of single-stage revision using intra-articular antibiotic infusion for treating culture-negative (CN) PJI. Methods. A retrospective analysis between 2009 and 2016 included 51 patients with CN PJI who underwent single-stage revision using intra-articular antibiotic infusion; these were compared with 192 culture-positive (CP) patients. CN patients were treated according to a protocol including intravenous vancomycin and a direct intra-articular infusion of imipenem and vancomycin alternately used in the morning and afternoon. In the CP patients, pathogen-sensitive intravenous (IV) antibiotics were administered for a mean of 16 days (12 to 21), and for resistant cases, additional intra-articular antibiotics were used. The infection healing rate, Harris Hip Score (HHS), and Hospital for Special Surgery (HSS) knee score were compared between CN and CP groups. Results. Of 51 CN patients, 46 (90.2%) required no additional medical treatment for recurrent infection at a mean of 53.2 months (24 to 72) of follow-up. Impaired kidney function occurred in two patients, and one patient had a local skin rash. No significant difference in the infection control rate was observed between CN and CP PJIs (90.2% (46/51) versus 94.3% (181/192); p = 0.297). The HHS of the CN group showed no substantial difference from that of CP cases (79 versus 81; p = 0.359). However, the CN group showed a mean HSS inferior to that of the CP group (76 versus 80; p = 0.027). Conclusion. Single-stage revision with direct intra-articular antibiotic infusion can be effective in treating CN PJI, and can achieve an infection control rate similar to that in CP patients. However, in view of systemic toxicity, local adverse reactions, and higher costs, additional strong evidence is needed to verify these treatment regimens. Cite this article: Bone Joint J 2020;102-B(3):336–344

Aims. Femoral revision component subsidence has been identified as predicting early failure in revision hip surgery. This comparative cohort study assessed the potential risk factors of subsidence in two commonly used femoral implant designs. Methods. A comparative cohort study was undertaken, analyzing a consecutive series of patients following revision total hip arthroplasties using either a tapered-modular (TM) fluted titanium or a porous-coated cylindrical modular (PCM) titanium femoral component, between April 2006 and May 2018. Clinical and radiological assessment was compared for both treatment cohorts. Risk factors for subsidence were assessed and compared. Results. In total, 65 TM and 35 PCM cases were included. At mean follow-up of seven years (1 to 13), subsidence was noted in both cohorts during the initial three months postoperatively (p < 0.001) then implants stabilized. Subsidence noted in 58.7% (38/65 cases) of the TM cohort (mean 2.3 mm, SD 3.5 mm) compared to 48.8% (17/35) of PCM cohort (mean 1.9 mm, SD 2.6 mm; p = 0.344). Subsidence of PCM cohort were significantly associated with extended trochanteric osteotomy (ETO) (p < 0.041). Although the ETO was used less frequently in PCM stem cohort (7/35), subsidence was noted in 85% (6/7) of them. Significant improvement of the final mean Oxford Hip Score (OHS) was reported in both treatment groups (p < 0.001). Conclusion. Both modular TM and PCM revision femoral components subsided within the femur. TM implants subsided more frequently than PCM components if the femur was intact but with no difference in clinical outcomes. However, if an ETO is performed then a PCM component will subside significantly more and suggests the use of a TM implant may be advisable. Cite this article: Bone Joint J 2020;102-B(6):709–715

Aims

Glenoid bone loss can be a challenging problem when revising a shoulder arthroplasty. Precise pre-operative planning based on plain radiographs or CT scans is essential. We have investigated a new radiological classification system to describe the degree of medialisation of the bony glenoid and that will indicate the amount of bone potentially available for supporting a glenoid component. It depends on the relationship between the most medial part of the articular surface of the glenoid with the base of the coracoid process and the spinoglenoid notch: it classifies the degree of bone loss into three types.

It also attempts to predict the type of glenoid reconstruction that may be possible (impaction bone grafting, structural grafting or simple non-augmented arthroplasty) and gives guidance about whether a pre-operative CT scan is indicated.

Aims. Antibiotic-loaded bone cements (ALBCs) may offer early protection against the formation of bacterial biofilm after joint arthroplasty. Use in hip arthroplasty is widely accepted, but there is a lack of evidence in total knee arthroplasty (TKA). The objective of this study was to evaluate the use of ALBC in a large population of TKA patients. Materials and Methods. Data from the National Joint Registry (NJR) of England and Wales were obtained for all primary cemented TKAs between March 2003 and July 2016. Patient, implant, and surgical variables were analyzed. Cox proportional hazards models were used to assess the influence of ALBC on risk of revision. Body mass index (BMI) data were available in a subset of patients. Results. Of 731 214 TKAs, 15 295 (2.1%) were implanted with plain cement and 715 919 (97.9%) with ALBC. There were 13 391 revisions; 2391 were performed for infection. After adjusting for other variables, ALBC had a significantly lower risk of revision for any cause (hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77 to 0.93; p < 0.001). ALBC was associated with a lower risk of revision for all aseptic causes (HR 0.85, 95% CI 0.77 to 0.95; p < 0.001) and revisions for infection (HR 0.84, 95% CI 0.67 to 1.01; p = 0.06). The results were similar when BMI was added into the model, and in a subanalysis where surgeons using only ALBC over the entire study period were excluded. Prosthesis survival at ten years for TKAs implanted with ALBC was 96.3% (95% CI 96.3 to 96.4) compared with 95.5% (95% CI 95.0 to 95.9) in those implanted with plain cement. On a population level, where 100 000 TKAs are performed annually, this difference represents 870 fewer revisions at ten years in the ALBC group. Conclusion. After adjusting for a range of variables, ALBC was associated with a significantly lower risk of revision in this registry-based study of an entire nation of primary cemented knee arthroplasties. Using ALBC does not appear to increase midterm implant failure rates. Cite this article: Bone Joint J 2019;101-B:1331–1347

Aims. This single-centre observational study aimed to describe the results of extensive bone impaction grafting of the whole acetabular cavity in combination with an uncemented component in acetabular revisions performed in a standardized manner since 1993. Methods. Between 1993 and 2013, 370 patients with a median age of 72 years (interquartile range (IQR) 63 to 79 years) underwent acetabular revision surgery. Of these, 229 were more than ten years following surgery and 137 were more than 15 years. All revisions were performed with extensive use of morcellized allograft firmly impacted into the entire acetabular cavity, followed by insertion of an uncemented component with supplementary screw fixation. All types of reoperation were captured using review of radiographs and medical charts, combined with data from the local surgical register and the Swedish Hip Arthroplasty Register. Results. Among patients with possible follow-up of ten and 15 years, 152 and 72 patients remained alive without revision of the acetabular component. The number of deaths was 61 and 50, respectively. Of those who died, six patients in each group had a reoperation performed before death. The number of patients with a reoperation was 22 for those with ten-year follow-up and 21 for those with 15 years of follow-up. The Kaplan-Meier implant survival rate for aseptic loosening among all 370 patients in the cohort was 96.3% (95% confidence interval (CI) 94.1 to 98.5) after ten years and 92.8% (95% CI 89.2 to 96.6) after 15 years. Conclusion. Extensive bone impaction grafting combined with uncemented revision components appears to be a reliable method with favourable long-term survival. This technique offers the advantage of bone stock restoration and disputes the long-standing perception that uncemented components require > 50% of host bone contact for successful implant survival. Cite this article: Bone Joint J 2020;102-B(2):198–204

Aims. A number of methods have been described to remove a well-fixed humeral implant as part of revision shoulder arthroplasty. These include the use of cortical windows and humeral osteotomies. The router bit extraction technique uses a high-speed router bit to disrupt the bone-implant interface. The implant is then struck in a retrograde fashion with a square-tip impactor and mallet. The purpose of this study was to determine the characteristics and frequency of the different techniques needed for the removal of a well-fixed humeral stem in revision shoulder arthroplasty. Patients and Methods. Between 2010 and 2018, 288 revision shoulder arthroplasty procedures requiring removal of a well-fixed humeral component were carried out at a tertiary referral centre by a single surgeon. The patient demographics, indications for surgery, and method of extraction were collected. Results. Of the 288 revisions, 284 humeral stems (98.6%) were removed using the router bit extraction technique alone. Four humeral stems (1.39%) required an additional cortical window. Humeral osteotomy was not necessary in any procedure. Most of the humeral stems removed (78.8%) were cementless. Of the four humeral stems that required a cortical window, three involved removal of a hemiarthroplasty. Two were cemented and two were cementless. Conclusion. The router bit extraction technique removed a well-fixed humeral component in a very high proportion of patients (98.6%). This method allows surgeons to avoid more invasive approaches involving a cortical window or humeral osteotomy, and their associated complications. Cite this article: Bone Joint J 2019;101-B:1280–1284

The term mid-flexion instability has entered the orthopaedic literature as a concept, but has not been confirmed as a distinct clinical entity. The term is used freely, sometimes as a synonym for flexion instability. However, the terms need to be clearly separated. A cadaver study published in 1990 associated joint line elevation with decreased stability at many angles of flexion, but that model was not typical of clinical scenarios. The literature is considered and it is proposed that the more common entity of an uncorrected flexion contracture after a measured resection arthroplasty technique is more likely to produce clinical findings that suggest instability mid-flexion.

It is proposed that the clinical scenario encountered is generalised instability, with the appearance of stability in full extension from tight posterior structures.

This paper seeks to clarify whether mid-flexion instability exists as an entity distinct from other commonly recognised forms of instability.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):84–8.

Aims. The aim of this study was to use national registry database information to estimate cumulative rates and relative risk of revision due to infection after reverse shoulder arthroplasty. Patients and Methods. We included 17 730 primary shoulder arthroplasties recorded between 2004 and 2013 in The Nordic Arthroplasty Register Association (NARA) data set. With the Kaplan–Meier method, we illustrated the ten-year cumulative rates of revision due to infection and with the Cox regression model, we reported the hazard ratios as a measure of the relative risk of revision due to infection. Results. In all, 188 revisions were reported due to infection during a mean follow-up of three years and nine months. The ten-year cumulative rate of revision due to infection was 1.4% overall, but 3.1% for reverse shoulder arthroplasties and 8.0% for reverse shoulder arthroplasties in men. Reverse shoulder arthroplasties were associated with an increased risk of revision due to infection also when adjusted for sex, age, primary diagnosis, and year of surgery (relative risk 2.41 (95% confidence interval 1.26 to 5.59); p = 0.001). Conclusion. The overall incidence of revision due to infection was low. The increased risk in reverse shoulder arthroplasty must be borne in mind, especially when offering it to men. Cite this article: Bone Joint J 2019;101-B:702–707

Aims. There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA. Methods. We retrospectively reviewed 88 cases which met the Musculoskeletal Infection Society (MSIS) criteria for PJI. Mean follow-up was seven years (1 to 14). Septic failure was diagnosed with a Delphi-based consensus definition. Any reoperation for mechanical causes in the absence of evidence of infection was considered as non-septic failure. A competing risk regression model was used to evaluate factors associated with septic and non-septic failures. A Kaplan-Meier estimate was used to analyze mortality. Results. The cumulative incidence of septic failure was 8% (95% confidence interval (CI) 3.5 to 15) at one year, 13.8% (95% CI 7.6 to 22) at two years, and 19.7% (95% CI 12 to 28.6) at five and ten years of follow-up. A femoral bone defect worse than Paprosky IIIA (hazard ratio (HR) 13.58 (95% CI 4.86 to 37.93); p < 0.001) and obesity (BMI ≥ 30 kg/m. 2. ; HR 3.88 (95% CI 1.49 to 10.09); p = 0.005) were significantly associated with septic failure. Instability and periprosthetic fracture were the most common reasons for mechanical failure (5.7% and 4.5%, respectively). The cumulative incidence of aseptic failure was 2% (95% CI 0.4 to 7) at two years, 9% (95% CI 4 to 17) at five years, and 12% (95% CI 5 to 22) at ten years. A previous revision to treat PJI was significantly associated with non-septic failure (HR 9.93 (95% CI 1.77 to 55.46); p = 0.009). At the five-year timepoint, 93% of the patients were alive (95% CI 84% to 96%), which fell to 86% (95% CI 75% to 92%) at ten-year follow-up. Conclusion. Massive femoral bone loss was associated with greater chances of developing a further septic failure. All septic failures occurred within the first five years following the one-stage exchange. Surgeons should be aware of instability and periprosthetic fracture being potential causes of further aseptic revision surgery. Cite this article: Bone Joint J 2021;103-B(7):1247–1253

Aims. Varus-valgus constrained (VVC) implants are often used during revision total knee arthroplasty (TKA) to gain coronal plane stability. However, the increased mechanical torque applied to the bone-cement interface theoretically increases the risk of aseptic loosening. We assessed mid-term survivorship, complications, and clinical outcomes of a fixed-bearing VVC device in revision TKAs. Methods. A total of 416 consecutive revision TKAs (398 patients) were performed at our institution using a single fixed-bearing VVC TKA from 2007 to 2015. Mean age was 64 years (33 to 88) with 50% male (199). Index revision TKA diagnoses were: instability (n = 122, 29%), aseptic loosening (n = 105, 25%), and prosthetic joint infection (PJI) (n = 97, 23%). All devices were cemented on the epiphyseal surfaces. Femoral stems were used in 97% (n = 402) of cases, tibial stems in 95% (n = 394) of cases; all were cemented. In total, 93% (n = 389) of cases required a stemmed femoral and tibial component. Femoral cones were used in 29%, and tibial cones in 40%. Survivorship was assessed via competing risk analysis; clinical outcomes were determined using Knee Society Scores (KSSs) and range of movement (ROM). Mean follow-up was four years (2 to 10). Results. The five-year cumulative incidence of subsequent revision for aseptic loosening and instability were 2% (95% confidence interval (CI) 0.2 to 3, number at risk = 154) and 4% (95% CI 2 to 6, number at risk = 153), respectively. The five-year cumulative incidence of any subsequent revision was 14% (95% CI 10 to 18, number at risk = 150). Reasons for subsequent revision included PJI (n = 23, of whom 12 had previous PJI), instability (n = 13), and aseptic loosening (n = 11). The use of this implant without stems was found to be a significant risk factor for subsequent revision (hazard ratio (HR) 7.58 (95% CI 3.98 to 16.03); p = 0.007). KSS improved from 46 preoperatively to 81 at latest follow-up (p < 0.001). ROM improved from 96° prerevision to 108° at latest follow-up (p = 0.016). Conclusion. The cumulative incidence of subsequent revision for aseptic loosening and instability was very low at five years with this fixed-bearing VVC implant in revision TKAs. Routine use of cemented and stemmed components with targeted use of metaphyseal cones likely contributed to this low rate of aseptic loosening. Cite this article: Bone Joint J 2020;102-B(4):458–462

Aims. Compared with primary total hip arthroplasty (THA), revision surgery can be challenging. The cement-in-cement femoral revision technique involves removing a femoral component from a well-fixed femoral cement mantle and cementing a new stem into the original mantle. This technique is widely used and when carried out for the correct indications, is fast, relatively inexpensive and carries a reduced short-term risk for the patient compared with the alternative of removing well-fixed cement. We report the outcomes of this procedure when two commonly used femoral stems are used. Patients and Methods. We identified 1179 cement-in-cement stem revisions involving an Exeter or a Lubinus stem reported to the Swedish Hip Arthroplasty Register (SHAR) between January 1999 and December 2015. Kaplan-Meier survival analysis was performed. Results. Survivorship is reported up to six years and was better in the Exeter group (91% standard deviation (. sd). 2.8% versus 85% . sd. 5.0%) (p = 0.02). There was, however, no significant difference in the survival of the stem and risk of re-revision for any reason (p = 0.58) and for aseptic loosening (p = 0.97), between revisions in which the Exeter stem (94% . sd. 2.2%; 98% . sd. 1.6%) was used compared with those in which the Lubinus stem (95% . sd. 3.2%; 98% . sd.  2.2%) was used. The database did not allow identification of whether a further revision was indicated for loosening of the acetabular or femoral component or both. Conclusion. The cement-in-cement technique for revision of the femoral component gave promising results using both designs of stem, six years post-operatively. Cite this article: Bone Joint J 2017;99-B(4 Supple B):27–32

Aims. During revision procedures for aseptic reasons, there remains a suspicion that failure may have been the result of an undetected subclinical infection. However, there is little evidence available in the literature about unexpected positive results in presumed aseptic revision spine surgery. The aims of our study were to estimate the prevalence of unexpected positive culture using sonication and to evaluate clinical characteristics of these patients. Patients and Methods. All patients who underwent a revision surgery after instrumented spinal surgery at our institution between July 2014 and August 2016 with spinal implants submitted for sonication were retrospectively analyzed. Only revisions presumed as aseptic are included in the study. During the study period, 204 spinal revisions were performed for diagnoses other than infection. In 38 cases, sonication cultures were not obtained, leaving a study cohort of 166 cases. The mean age of the cohort was 61.5 years (. sd. 20.4) and there were 104 female patients. Results. Sonication cultures were positive in 75 cases (45.2%). Hardware failure was the most common indication for revision surgery and revealed a positive sonication culture in 26/75 cases (35%) followed by adjacent segment disease (ASD) in 23/75 cases (30%). Cutibacterium acnes and Staphylococcus epidermidis were the most commonly isolated microorganisms, observed in 45% and 31% of cases, respectively. C. acnes was isolated in 65.2% of cases when the indication for revision surgery was ASD. Conclusion. Infection must always be considered as a possibility in the setting of spinal revision surgery, especially in the case of hardware failure, regardless of the lack of clinical signs. Sonication should be routinely used to isolate microorganisms adherent to implants. Cite this article: Bone Joint J 2019;101-B:621–624

Aims. Periprosthetic joint infection (PJI) remains a challenging complication following total hip arthroplasty (THA). It is associated with high levels of morbidity, mortality and expense. Guidelines and protocols exist for the management of culture-positive patients. Managing culture-negative patients with a PJI poses a greater challenge to surgeons and the wider multidisciplinary team as clear guidance is lacking. Patients and Methods. We aimed to compare the outcomes of treatment for 50 consecutive culture-negative and 50 consecutive culture-positive patients who underwent two-stage revision THA for chronic infection with a minimum follow-up of five years. Results. There was no significant difference in the outcomes between the two groups of patients, with a similar rate of re-infection of 6%, five years post-operatively. Culture-negative PJIs were associated with older age, smoking, referral from elsewhere and pre-operative antibiotic treatment. The samples in the culture-negative patients were negative before the first stage (aspiration), during the first-stage (implant removal) and second-stage procedures (re-implantation). Conclusion. Adherence to strict protocols for selecting and treating culture-negative patients with a PJI using the same two-stage revision approach that we employ for complex culture-positive PJIs is important in order to achieve control of the infection in this difficult group of patients. Cite this article: Bone Joint J 2018;(1 Supple A)100-B:3–8

Aims. The aim of this study was to compare the rate of perioperative complications following aseptic revision total hip arthroplasty (THA) in patients aged ≥ 80 years with that in those aged < 80 years, and to identify risk factors for the incidence of serious adverse events in those aged ≥ 80 years using a large validated national database. Patients and Methods. Patients who underwent aseptic revision THA were identified in the 2005 to 2015 National Surgical Quality Improvement Program (NSQIP) database and stratified into two age groups: those aged < 80 years and those aged ≥ 80 years. Preoperative and procedural characteristics were compared. Multivariate regression analysis was used to compare the risk of postoperative complications and readmission. Risk factors for the development of a serious adverse event in those aged ≥ 80 years were characterized. Results. The study included 7569 patients aged < 80 years and 1419 were aged ≥ 80 years. Multivariate analysis showed a higher risk of perioperative mortality, pneumonia, urinary tract infection and the requirement for a blood transfusion and an extended length of stay in those aged ≥ 80 years compared with those aged < 80 years. Independent risk factors for the development of a serious adverse event in those aged ≥ 80 years include an American Society of Anesthesiologists score of ≥ 3 and procedures performed under general anaesthesia. Conclusion. Even after controlling for patient and procedural characteristics, aseptic revision THA is associated with greater risks in patients aged ≥ 80 years compared with younger patients. This is important for counselling and highlights the need for medical optimization in these vulnerable patients. Cite this article: Bone Joint J 2018;100-B:143–51

Aims. We present the clinical and radiological results at a minimum follow-up of five years for patients who have undergone multiple cement-in-cement revisions of their femoral component at revision total hip arthroplasty (THA). Patients and Methods. We reviewed the outcome on a consecutive series of 24 patients (10 men, 14 women) (51 procedures) who underwent more than one cement-in-cement revision of the same femoral component. The mean age of the patients was 67.5 years (36 to 92) at final follow-up. Function was assessed using the original Harris hip score (HHS), Oxford Hip Score (OHS) and the Merle D’Aubigné Postel score (MDP). Results. The mean length of follow-up was 81.7 months (64 to 240). A total of 41 isolated acetabular revisions were performed in which stem removal facilitated access to the acetabulum, six revisions were conducted for loosening of both components and two were isolated stem revisions (each of these patients had undergone at least two revisions). There was significant improvement in the OHS (p = 0.041), HHS (p = 0.019) and MDP (p = 0.042) scores at final follow-up There were no stem revisions for aseptic loosening. Survival of the femoral component was 91.9% (95% confidence intervals (CI) 71.5 to 97.9) at five years and 91.7% (95% CI 70 to 97) at ten years (number at risk 13), with stem revision for all causes as the endpoint. Conclusion. Cement-in-cement revision is a viable technique for performing multiple revisions of the well cemented femoral component during revision total hip arthroplasty at a minimum of five years follow-up. Cite this article: Bone Joint J 2017;99-B:199–203

Aims. Revision total knee arthroplasty (rTKA) accounts for approximately 5% to 10% of all TKAs. Although the complexity of these procedures is well recognized, few investigators have evaluated the cost and value-added with the implementation of a dedicated revision arthroplasty service. The aim of the present study is to compare and contrast surgeon productivity in several differing models of activity. Materials and Methods. All patients that underwent primary or revision TKA from January 2016 to June 2018 were included as the primary source of data. All rTKA patients were categorized by the number of components revised (e.g. liner exchange, two or more components). Three models were used to assess the potential surgical productivity of a dedicated rTKA service : 1) work relative value unit (RVU) versus mean surgical time; 2) primary TKA with a single operating theatre (OT) versus rTKA with a single OT; and 3) primary TKA with two OTs versus rTKA with a single OT. Results. In total, 4570 procedures were performed: 4128 primary TKAs, 51 TKA liner exchanges, and 391 full rTKAs. Surgical time was significantly different between the primary TKA, liner exchange, and rTKA cohorts (100.6, 97.1, and 141.7 minutes, respectively; p < 0.001). Primary TKA yielded a mean of 7.1% more RVU/min per procedure than rTKA. Our one-OT model demonstrated that primary TKA (n = 4) had a 1.9% RVU/day advantage over rTKA (n = 3). If two OTs are used for primary TKA (n = 6), the outcome strongly favours primary TKA by an added 34.6% RVUs/day. Conclusion. Our results suggest that a dedicated rTKA service would lead to lower surgeon remuneration based on the current RVU paradigm. Revision arthroplasty specialists may need additional or alternative incentives to promote the development of a dedicated revision service. Through such an approach, healthcare organizations could enhance the quality of care provided, but surgeon productivity measures would need to be adjusted to reflect the burden of these cases. Cite this article: Bone Joint J 2019;101-B:675–681

Aims. The purpose of this study is to determine if higher volume hospitals have lower costs in revision hip and knee arthroplasty. Materials and Methods. We questioned the Centres for Medicare and Medicaid Services (CMS) Inpatient Charge Data and identified 789 hospitals performing a total of 29 580 revision arthroplasties in 2014. Centres were dichotomised into high-volume (performing over 50 revision cases per year) and low-volume. Mean total hospital-specific charges and inpatient payments were obtained from the database and stratified based on Diagnosis Related Group (DRG) codes. Patient satisfaction scores were obtained from the multiyear CMS Hospital Compare database. Results. High-volume hospitals comprised 178 (30%) of the total but performed 15 068 (51%) of all revision cases, including 509 of 522 (98%) of the most complex DRG 466 cases. While high-volume hospitals had higher Medicare inpatient payments for DRG 467 ($21 458 versus $20 632, p = 0.038) and DRG 468 ($17 003 versus $16 120, p = 0.011), there was no difference in hospital specific charges between the groups. Higher-volume facilities had a better CMS hospital star rating (3.63 versus 3.35, p < 0.001). When controlling for hospital geographic and demographic factors, high-volume revision hospitals are less likely to be in the upper quartile of inpatient Medicare costs for DRG 467 (odds ratio (OR) 0.593, 95% confidence intervals (CI) 0.374 to 0.941, p = 0.026) and DRG 468 (OR 0.451, 95% CI 0.297 to 0.687, p <  0.001). Conclusion. While a high-volume hospital is less likely to be a high cost outlier, the higher mean Medicare reimbursements at these facilities may be due to increased case complexity. Further study should focus on measures for cost savings in revision total joint arthroplasties. Cite this article: Bone Joint J 2017;99-B:1611–17

Aims. Although good clinical outcomes have been reported for monolithic tapered, fluted, titanium stems (TFTS), early results showed high rates of subsidence. Advances in stem design may mitigate these concerns. This study reports on the use of a current monolithic TFTS for a variety of indications. Methods. A multi-institutional retrospective study of all consecutive total hip arthroplasty (THA) and revision total hip arthroplasty (rTHA) patients who received the monolithic TFTS was conducted. Surgery was performed by eight fellowship-trained arthroplasty surgeons at four institutions. A total of 157 hips in 153 patients at a mean follow-up of 11.6 months (SD7.8) were included. Mean patient age at the time of surgery was 67.4 years (SD 13.3) and mean body mass index (BMI) was 28.9 kg/m. 2. (SD 6.5). Outcomes included intraoperative complications, one-year all-cause re-revisions, and subsidence at postoperative time intervals (two weeks, six weeks, six months, nine months, and one year). Results. There were eight intraoperative complications (4.9%), six of which were intraoperative fractures; none occurred during stem insertion. Six hips (3.7%) underwent re-revision within one year; only one procedure involved removal of the prosthesis due to infection. Mean total subsidence at latest follow-up was 1.64 mm (SD 2.47). Overall, 17 of 144 stems (11.8%) on which measurements could be performed had >5 mm of subsidence, and 3/144 (2.1%) had >10 mm of subsidence within one year. A univariate regression analysis found that additional subsidence after three months was minimal. A multivariate regression analysis found that subsidence was not significantly associated with periprosthetic fracture as an indication for surgery, the presence of an extended trochanteric osteotomy (ETO), Paprosky classification of femoral bone loss, stem length, or type of procedure performed (i.e. full revision vs conversion/primary). Conclusion. Advances in implant design, improved trials, a range of stem lengths and diameters, and high offset options mitigate concerns of early subsidence and dislocation with monolithic TFTS, making them a valuable option for femoral revision. Cite this article: Bone Joint J 2020;102-B(2):191–197

Peri-prosthetic infection is amongst the most common causes of failure following total knee replacement (TKR). In the presence of established infection, thorough joint debridement and removal of all components is necessary following which new components may be implanted. This can be performed in one or two stages; two-stage revision with placement of an interim antibiotic-loaded spacer is regarded by many to be the standard procedure for eradication of peri-prosthetic joint infection. . We present our experience of a consecutive series of 50 single-stage revision TKRs for established deep infection performed between 1979 and 2010. There were 33 women and 17 men with a mean age at revision of 66.8 years (42 to 84) and a mean follow-up of 10.5 years (2 to 24). The mean time between the primary TKR and the revision procedure was 2.05 years (1 to 8). Only one patient required a further revision for recurrent infection, representing a success rate of 98%. Nine patients required further revision for aseptic loosening, according to microbiological testing of biopsies taken at the subsequent surgery. Three other patients developed a further septic episode but none required another revision. These results suggest that a single-stage revision can produce comparable results to a two-stage revision. Single-stage revision offers a reduction in costs as well as less morbidity and inconvenience for patients. Cite this article: Bone Joint J 2014;96-B:759–64

Aims. The aim of this study was to present a series of patients with aseptic failure of a total ankle arthroplasty (TAA) who were treated with fusion of the hindfoot using a nail. Patients and Methods. A total of 23 TAAs, in 22 patients, were revised for aseptic loosening and balloon osteolysis to a hindfoot fusion by a single surgeon (NH) between January 2012 and August 2014. The procedure was carried out without bone graft using the Phoenix, Biomet Hindfoot Arthrodesis Nail. Preoperative investigations included full blood count, CRP and ESR, and radiological investigations including plain radiographs and CT scans. Postoperative plain radiographs were assessed for fusion. When there was any doubt, CT scans were performed. Results. The mean follow-up was 13.9 months (4.3 to 37.2). Union occurred at the tibiotalar joint in 22 ankles (95.6%) with one partial union. Union occurred at the subtalar joint in 20 ankles (87%) of cases with two nonunions. The nail broke in one patient with a subtalar nonunion and revision was undertaken. The only other noted complication was one patient who suffered a stress fracture at the proximal aspect of the nail, which was satisfactorily treated conservatively. Conclusion. This study represents the largest group of patients reported to have undergone revision TAA to fusion of the hindfoot with good results. Cite this article: Bone Joint J 2018;100-B:475–9

Although it has been suggested that the outcome after revision of a unicondylar knee replacement (UKR) to total knee replacement (TKR) is better when the mechanism of failure is understood, a comparative study on this subject has not been undertaken. A total of 30 patients (30 knees) who underwent revision of their unsatisfactory UKR to TKR were included in the study: 15 patients with unexplained pain comprised group A and 15 patients with a defined cause for pain formed group B. The Oxford knee score (OKS), visual analogue scale for pain (VAS) and patient satisfaction were assessed before revision and at one year after revision, and compared between the groups. The mean OKS improved from 19 (10 to 30) to 25 (11 to 41) in group A and from 23 (11 to 45) to 38 (20 to 48) in group B. The mean VAS improved from 7.7 (5 to 10) to 5.4 (1 to 8) in group A and from 7.4 (2 to 9) to 1.7 (0 to 8) in group B. There was a statistically significant difference between the mean improvements in each group for both OKS (p = 0.022) and VAS (p = 0.002). Subgroup analysis in group A, performed in order to define a patient factor that predicts outcome of revision surgery in patients with unexplained pain, showed no pre-operative differences between both subgroups. These results may be used to inform patients about what to expect from revision surgery, highlighting that revision of UKR to TKR for unexplained pain generally results in a less favourable outcome than revision for a known cause of pain. Cite this article: Bone Joint J 2013;95-B:1204–8

The aim of this study was to review the early outcome of the Femoro-Patella Vialla (FPV) joint replacement. A total of 48 consecutive FPVs were implanted between December 2007 and June 2011. Case-note analysis was performed to evaluate the indications, operative histology, operative findings, post-operative complications and reasons for revision. The mean age of the patients was 63.3 years (48.2 to 81.0) and the mean follow-up was 25.0 months (6.1 to 48.9). Revision was performed in seven (14.6%) at a mean of 21.7 months, and there was one re-revision. Persistent pain was observed in three further patients who remain unrevised. The reasons for revision were pain due to progressive tibiofemoral disease in five, inflammatory arthritis in one, and patellar fracture following trauma in one. No failures were related to the implant or the technique. Trochlear dysplasia was associated with a significantly lower rate of revision (5.9% vs 35.7%, p = 0.017) and a lower incidence of revision or persistent pain (11.8% vs 42.9%, p = 0.045). . Focal patellofemoral osteoarthritis secondary to trochlear dysplasia should be considered the best indication for patellofemoral replacement. Standardised radiological imaging, with MRI to exclude overt tibiofemoral disease should be part of the pre-operative assessment, especially for the non-dysplastic knee. Cite this article: Bone Joint J 2013;95-B:793–7

Aims. We aimed to report the mid- to long-term rates of septic and aseptic failure after two-stage revision surgery for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). Methods. We retrospectively reviewed 96 cases which met the Musculoskeletal Infection Society criteria for PJI. The mean follow-up was 90 months (SD 32). Septic failure was assessed using a Delphi-based consensus definition. Any further surgery undertaken for aseptic mechanical causes was considered as aseptic failure. The cumulative incidence with competing risk analysis was used to predict the risk of septic failure. A regression model was used to evaluate factors associated with septic failure. The cumulative incidence of aseptic failure was also analyzed. Results. There were 23 septic failures at final follow-up, with a cumulative incidence of 14% (95% confidence interval (CI) 8% to 22%) at one year, 18% (95% CI 11% to 27%) at two years, 22% (95% CI 14% to 31%) at five years, and 23% (95% CI 15% to 33%) at ten years. Having at least one positive culture (hazard ratio (HR) 2.38 (interquartile range (IQR) 1.19 to 4.74); p = 0.013), or a positive intraoperative frozen section (HR 2.55 (IQR 1.06 to 6.15); p = 0.037) was significantly associated with septic failure after reimplantation. With dislocation being the most common cause of aseptic revision (5.2%), the cumulative incidence of aseptic failure was 1% (95% CI 0% to 5%) at one year, 6% (95% CI 1% to 8%) at five years, and 8% (95%CI 3% to 17%) at ten years. Conclusion. If there is no recurrent infection in the five years following reimplantation, the chances of further infection thereafter are remote. While the results of a frozen section may be a reliable guide to the timing of reimplantation, intraoperative culture has, currently, only prognostic value. Surgeons should be aware that instability remains a potential indication for further revision surgery. Cite this article: Bone Joint J 2021;103-B(1):79–86

Aims. Femoral stems with exchangeable (modular) necks were introduced to offer surgeons an increased choice when determining the version, offset and length of the femoral neck during total hip arthroplasty (THA). It was hoped that this would improve outcomes and reduce complications, particularly dislocation. In 2010, the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) first reported an increased rate of revision after primary THA using femoral stems with an exchangeable neck. The aim of this study was to provide a more comprehensive up-to-date analysis of primary THA using femoral stems with exchangeable and fixed necks. Materials and Methods. The data included all primary THA procedures performed for osteoarthritis (OA), reported to the AOANJRR between 01 September 1999 and 31 December 2014. There were 9289 femoral stems with an exchangeable neck and 253 165 femoral stems with a fixed neck. The characteristics of the patients and prostheses including the bearing surface and stem/neck metal combinations were examined using Cox proportional hazard ratios (HRs) and Kaplan-Meier estimates of survivorship. . Results. It was found that prostheses with an exchangeable neck had a higher rate of revision and this was evident regardless of the bearing surface or the size of the femoral head. Exchangeable neck prostheses with a titanium stem and a cobalt-chromium neck had a significantly higher rate of revision compared with titanium stem/titanium neck combinations (HR 1.83, 95% confidence interval 1.49 to 2.23, p < 0.001). Revisions were higher for these combinations compared with femoral stems with a fixed neck. Conclusion . There appears to be little evidence to support the continued use of prostheses with an exchangeable neck in primary THA undertaken for OA. Cite this article: Bone Joint J 2017;99-B:766–73

Revision after failed femoral components may be technically demanding due to loss of peri-prosthetic bone. This retrospective study evaluated the long-term results of femoral revision using the cementless Wagner Self-Locking stem. Between 1992 and 1998, 68 consecutive hips in 66 patients underwent femoral revision using this implant. A total of 25 patients died from unrelated causes without further revision; the remaining 41 hips in 41 patients (12 men and 29 women) with a mean age of 61 years (29 to 80) were reviewed at a mean follow-up of 13.9 years (10.4 to 15.8). A transfemoral approach was used in 32 hips. A total of five stems required further revision because of infection in two, progressive subsidence in two and recurrent dislocation in one. Four hips had dislocated and eight stems had subsided ≥ 10 mm. The mean Harris hip score improved from 33 points pre-operatively to 75 points at final follow-up (p < 0.001). In all, 33 stems (91.7%) showed radiological signs of stable bone fixation. The cumulative survival rates at 15.8 years with femoral revision for any reason and for stem failure as the endpoints were 92.0% (95% confidence interval (CI) 86.0% to 98.4%) and 96.6% (95% CI 92.2% to 100%), respectively. The survivorship with revision and ≥ 10 mm migration of the stem as the endpoint was 83.6% (95% CI 76.6% to 91.4%). This study shows quite good survival and moderate clinical outcome when using a monoblock tapered titanium stem for supporting the regeneration of bone in complex revision hip surgery.

Fungal peri-prosthetic infections of the knee and hip are rare but likely to result in devastating complications. In this study we evaluated the results of their management using a single-stage exchange technique. Between 2001 and 2011, 14 patients (ten hips, four knees) were treated for a peri-prosthetic fungal infection. One patient was excluded because revision surgery was not possible owing to a large acetabular defect. One patient developed a further infection two months post-operatively and was excluded from the analysis. Two patients died of unrelated causes. After a mean of seven years (3 to 11) a total of ten patients were available for follow-up. One patient, undergoing revision replacement of the hip, had a post-operative dislocation. Another patient, undergoing revision replacement of the knee, developed a wound infection and required revision 29 months post-operatively following a peri-prosthetic femoral fracture. . The mean Harris hip score increased to 74 points (63 to 84; p < 0.02) in those undergoing revision replacement of the hip, and the mean Hospital for Special Surgery knee score increased to 75 points (70 to 80; p < 0.01) in those undergoing revision replacement of the knee. . A single-stage revision following fungal peri-prosthetic infection is feasible, with an acceptable rate of a satisfactory outcome. Cite this article: Bone Joint J 2014;96-B:492–6

Aims. The aim of this study was to determine whether the rates of revision for metal-on-metal (MoM) total hip arthroplasties (THAs) with Pinnacle components varied according to the year of the initial operation, and compare these with the rates of revision for other designs of MoM THA. Patients and Methods. Data from the National Joint Registry for England and Wales included 36 mm MoM THAs with Pinnacle acetabular components which were undertaken between 2003 and 2012 with follow-up for at least five years (n = 10 776) and a control group of other MoM THAs (n = 13 817). The effect of the year of the primary operation on all-cause rates of revision was assessed using Cox regression and interrupted time-series analysis. Results. For MoM THAs involving Pinnacle components, those undertaken between 2007 and 2012 had higher rates of revision compared with those undertaken between 2004 and 2006 (hazard ratio (HR) 2.01; 95% confidence interval (CI) 1.57 to 2.57; p < 0.001). For THAs undertaken during and after 2007, the number of revisions per 1000 implant-years at risk significantly increased by 5.20 (95% CI 0.52 to 9.89; p = 0.033) compared with those undertaken before this time. In the control group, THAs undertaken between 2007 and 2012 also had higher rates of revision (HR 1.77; 95% CI 1.49 to 2.10; p < 0.001), with revisions per 1000 implant-years for those undertaken during and after 2007 significantly increasing by 6.13 (95% CI 1.42 to 10.83; p = 0.016). Conclusion. The five-year revision rates were significantly increased for all primary MoM THAs undertaken from 2007 onwards. Contrary to recent reports, this finding was not specific to those involving Pinnacle acetabular components and may be explained by increased surveillance and recent lowering of the threshold for revision. Cite this article: Bone Joint J 2018;100-B:33–41

In a systematic review, reports from national registers and clinical studies were identified and analysed with respect to revision rates after joint replacement, which were calculated as revisions per 100 observed component years. After primary hip replacement, a mean of 1.29 revisions per 100 observed component years was seen. The results after primary total knee replacement are 1.26 revisions per 100 observed component years, and 1.53 after medial unicompartmental replacement. After total ankle replacement a mean of 3.29 revisions per 100 observed component years was seen. The outcomes of total hip and knee replacement are almost identical. Revision rates of about 6% after five years and 12% after ten years are to be expected

Aims. Fretting and corrosion at the modular head/neck junction, known as trunnionosis, in total hip arthroplasty (THA) is a cause of adverse reaction to metal debris (ARMD). We describe the outcome of revision of metal-on-polyethylene (MoP) THA for ARMD due to trunnionosis with emphasis on the risk of major complications. Patients and Methods. A total of 36 patients with a MoP THA who underwent revision for ARMD due to trunnionosis were identified. Three were excluded as their revision had been to another metal head. The remaining 33 were revised to a ceramic head with a titanium sleeve. We describe the presentation, revision findings, and risk of complications in these patients. Results. The patients presented with pain, swelling, stiffness, or instability and an inflammatory mass was confirmed radiologically. Macroscopic material deposition on the trunnion was seen in all patients, associated with ARMD. Following revision, six (18.2%) dislocated, requiring further revision in four. Three (9.1%) developed a deep infection and six (18.2%) had significant persistent pain without an obvious cause. One developed a femoral artery thrombosis after excision of an iliofemoral pseudotumor, requiring a thrombectomy. Conclusion. The risk of serious complications following revision MoP THA for ARMD associated with trunnionosis is high. In the presence of extensive tissue damage, a constrained liner or dual mobility construct is recommended in these patients. Cite this article: Bone Joint J 2018;100-B:720–4