Despite excellent results, the use of cemented total hip replacement (THR) is declining. This retrospective cohort study records survival time to revision following primary cemented THR using the most common combination of components that accounted for almost a quarter of all cemented THRs, exploring risk factors independently associated with failure. All patients with osteoarthritis who had an Exeter V40/Contemporary THR (Stryker) implanted before 31 December 2010 and recorded in the National Joint Registry for England and Wales were included in the analysis. Cox’s proportional hazard models were used to analyse the extent to which risk of revision was related to patient, surgeon and implant covariates, with a significance threshold of p < 0.01. A total of 34 721 THRs were included in the study. The overall seven-year rate of revision for any reason was 1.70% (99% confidence interval (CI) 1.28 to 2.12). In the final adjusted model the risk of revision was significantly higher in THRs with the Contemporary hooded component (hazard ratio (HR) 1.88, p < 0.001) than with the flanged version, and in smaller head sizes (< 28 mm) compared with 28 mm diameter heads (HR 1.50, p = 0.005). The seven-year revision rate was 1.16% (99% CI 0.69 to 1.63) with a 28 mm diameter head and flanged component. The overall risk of revision was independent of age, gender, American Society of Anesthesiologists grade, body mass index, surgeon volume, surgical approach, brand of cement/presence of antibiotic, femoral head material (stainless steel/alumina) and stem taper size/offset. However, the risk of revision for dislocation was significantly higher with a ‘plus’ offset head (HR 2.05, p = 0.003) and a hooded acetabular component (HR 2.34, p < 0.001). In summary, we found that there were significant differences in failure between different designs of acetabular component and sizes of femoral head after adjustment for a range of covariates

Objectives

The Kaplan-Meier estimation is widely used in orthopedics to calculate the probability of revision surgery. Using data from a long-term follow-up study, we aimed to assess the amount of bias introduced by the Kaplan-Meier estimator in a competing risk setting.

Revision arthroplasty of the hip is expensive owing to the increased cost of pre-operative investigations, surgical implants and instrumentation, protracted hospital stay and drugs. We compared the costs of performing this surgery for aseptic loosening, dislocation, deep infection and peri-prosthetic fracture. Clinical, demographic and economic data were obtained for 305 consecutive revision total hip replacements in 286 patients performed at a tertiary referral centre between 1999 and 2008. The mean total costs for revision surgery in aseptic cases (n = 194) were £11 897 (sd 4629), for septic revision (n = 76) £21 937 (sd 10 965), for peri-prosthetic fracture (n = 24) £18 185 (sd 9124), and for dislocation (n = 11) £10 893 (sd 5476). Surgery for deep infection and peri-prosthetic fracture was associated with longer operating times, increased blood loss and an increase in complications compared to revisions for aseptic loosening. Total inpatient stay was also significantly longer on average (p < 0.001). Financial costs vary significantly by indication, which is not reflected in current National Health Service tariffs.

Total hip replacement (THR) still is a rare intervention in many African countries. In Burkina Faso it is not performed on a regular basis. A visiting programme for THR was started in a district hospital with no previous relevant experience. In this paper we present an analysis of the surgical technical problems and peri-operative complications of 152 THRs in 136 patients and three bipolar hemiarthroplasties in three patients undertaken in this new programme with limited orthopaedic equipment. There were 86 male and 53 female patients with a mean age of 49 years (21 to 78). We identified 77 intra-operative technical problems in 51 operations. There were 24 peri-operative complications in 21 patients, 17 of which were bony in nature. So far, ten revision THRs have been performed in nine patients.

Regular analysis of the technical problems and complications was used to improve quality, and we identified patient selection adapted to the local circumstances as important to avoid complications. Our reflections on the problems encountered in initiating such a programme may be of help to other teams planning similar projects.

Cite this article: Bone Joint J 2014;96-B:177–80.

In recent years, there has been increasing interest in the use of simultaneous hip arthroplasty compared to staged procedures in patients with bilateral pathology. The aim of this study was to compare simultaneous and staged hip arthroplasty in patients with bilateral pathology by assessing the transfusion rate, postoperative hemoglobin drop, length of stay (LOS), in-hospital complications, 30-days readmissions, leg length difference and early functional outcome. We conducted a retrospective cohort study that included all patients who were undergoing primary total hip arthroplasty (THA) by a single surgeon in a high-volume arthroplasty center between 2015 and 2020 as simultaneous or staged procedures. Staged bilateral arthroplasties were performed within 12 months and were stratified by the time between procedures. Data was acquired through the electronic files at the Orthopädische Chirurgie München (OCM). For functional outcome we compared the ability of the patients to walk independently on the ward and the ability to walk a set of stairs alone which was recorded daily by the attending physiotherapist. In total n=290 patients were assessed for eligibility and included in this study. One hundred and thirty eight patients were allocated to the staged arthroplasty group. The second staged procedure was performed within 12 months of the first procedure. One hundred and fifty two patients were allocated to the simultaneous arthroplasty group. No statistical difference was found between the two groups regarding demographic data. Primary outcome measurements: There was no significant difference in transfusion rate or complication rate (p=0.1147). In both groups the transfusion rate was actually 0%. Secondarily, no statistically significant difference was found between the postoperative hemoglobin drop (p=0.1147) and the functional outcome (p=0.7249), nor the length of stay (LOS) (p=: 0.6415), as well as the 30 days readmission rate between both groups. No difference was found in leg length in the simultaneous group. The OR time in the simultaneous group ranged from 62min to 111min with an average of 77min. No surgery exceeded a 120min window. We observed no significant differences in transfusion rate, in hospital complications, as well as readmission rate between both groups. The early functional outcome showed no significant difference in mobility. Simultaneous hip arthroplasty is as safe as a staged procedure, with no higher risk for the patient, in a specialized high volume center with a specialized surgeon and an adequate team. Level of evidence: Level IV

In a double-blinded randomised controlled trial, 83 patients with primary osteoarthritis of the hip received either a ceramic-on-metal (CoM) or metal-on-metal (MoM) total hip replacement (THR). The implants differed only in the bearing surfaces used. The serum levels of cobalt and chromium and functional outcome scores were compared pre-operatively and at six and 12 months post-operatively.

Data were available for 41 CoM and 36 MoM THRs (four patients were lost to follow-up, two received incorrect implants). The baseline characteristics of both cohorts were similar. Femoral head size measured 36 mm in all but two patients who had 28 mm heads. The mean serum cobalt and chromium levels increased in both groups, with no difference noted between groups at six months (cobalt p = 0.67, chromium p = 0.87) and 12 months (cobalt p = 0.76, chromium p = 0.76) post-operatively. Similarly, the mean Oxford hip scores, Western Ontario and McMaster Universities Osteoarthritis index and University of California, Los Angeles activity scores showed comparable improvement at 12 months.

Our findings indicate that CoM and MoM couplings are associated with an equivalent increase in serum cobalt and chromium levels, and comparable functional outcome scores at six and 12-months follow-up.

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

The trend towards more minimal access has led to a series of instruments being developed to enable adequate access for Direct Anterior Approach (DAA) for hip arthroplasty. These include longer levers, hooks attached to the operating table and a series of special attachments to the operating table to position the leg and apply traction where necessary. The forces applied in this way may be transmitted locally, damaging muscle used as a fulcrum, or the knee and ankle joints when torque has to be applied to the femur through a boot. The arthroplasty surgeon's aim is to minimise the forces applied to both bone and soft tissue during surgery. We surmised that the forces needed for adequate access were related to the extent of the capsular and soft tissue releases, and that they could be measured and optimised. with the aim of minimising the forces applied to the tissues around the hip. Eight fresh frozen specimens from pelvis to mid tibia from four cadavers were approached using the DAA. A 6-axis force/torque sensor and 6-axis motion tracking sensor were attached to a threaded rod securely fastened to the tibial and femoral diaphysis. The torque needed to provide first extension, then external rotation, adequate for hip arthroplasty were measured as the capsular structures were divided sequentially. The Zona Orbicularis (ZO) and Ischiofemoral Ligament(IFL) contributed most of the resistance to both extension (4.0 and 3.1Nm) and external rotation torque (5.8 and 3.9Nm). The contributions of the conjoint tendon (1.5 and 2.4Nm) and piriformis (1.2 and 2.3Nm) were substantially smaller. By releasing the Zona Orbicularis and Ischiofemoral Ligament, the torque needed to deliver the femur for hip arthroplasty could be reduced to less than the torque needed to open a jar (2.9–5.5Nm)

Climbers and mountaineers will present to arthroplasty surgeons in need of hip replacement surgeries. There is a lack of guidance for both parties with a paucity in the literature. Climbing is often considered a high-risk activity to perform with a total hip replacement, due to the positions the hip is weighted in, and the potential austere environment in which an injury may occur. The aim was to assess levels of climbing and mountaineering possible following hip arthroplasty, and any factors affecting these levels. Ethical approval was obtained from the University of Central Lancashire. An anonymous online questionnaire was disseminated via email, social media and word-of-mouth to include all climbers, hill-walkers or mountaineers across the UK. This was used to collect climbing and mountaineering ability at various timepoints, along with scores such as the Oxford Hip Score and UCLA Score. The Kappa statistic was used to assess for correlations. Of the responders, 28 had undergone right hip arthroplasty surgery, with 11 having left hips and 22 receiving bilateral hips. A total of 67 of the replaced hips were total hip replacements, with 16 having undergone hip resurfacing. There is a fair agreement in level of climbing ability 3 months pre- and 3 months post-operatively (kappa=0.287, p<0.001), and a substantial agreement between 1 year post-operatively and currently for both climbing (kappa=0.730, p<0.001) and mountaineering (kappa=0.684, p<0.001). Impressively, 17 participants are climbing at more than E1 trad or 6c sport at one or more time points post operatively, which is regarded as an advanced level within the climbing community. Out of those 17 participants, 8 were climbing at this level within 3 months post-operatively. The level of climbing possible following hip arthroplasty surgery is above what is expected and perhaps desired by the operating surgeon. It is essential to take the individual patient into account when planning an operative intervention such as arthroplasty. The one year post-operative time point is highly predictive of longer term outcomes for both climbing and mountaineering

Aims. With increasing burden of revision hip arthroplasty (THA), one of the major challenges is the management of proximal femoral bone loss associated with previous multiple surgeries. Proximal femoral arthroplasty (PFA) has already been popularized for tumour surgeries. Our aim was to describe the outcome of using PFA in these demanding non-neoplastic cases. Methods. A retrospective review of 25 patients who underwent PFA for non-neoplastic indications between January 2009 and December 2015 was undertaken. Their clinical and radiological outcome, complication rates, and survival were recorded. All patients had the Stanmore Implant – Modular Endo-prosthetic Tumour System (METS). Results. At mean follow-up of 5.9 years, there were no periprosthetic fractures. Clearance of infection was achieved in 63.6% of cases. One hip was re-revised to pseudo arthroplasty for deep infection. Instability was noted in eight of the hips (32%), of which seven needed further surgery. Out of these eight hips with instability, five had preoperative infection. Deep infection was noted in five of the hips (20%), of which four were primarily revised for infection. One patient had aseptic loosening of the femoral component and awaits revision surgery. The Kaplan-Meier survivorship free of revision of any component for any reason was 72% (95% confidence interval (CI) 51.3% to 92.7%), and for revisions of only femoral component for any reason was 96% (95% CI 86.3% to 105.7%) at five years. Conclusion. Dislocation and infection remain the major cause for failure, particularly in patients with pre-existing infection. The use of dual mobility cups, silver-coated implants, and less aggressive postoperative rehabilitation regimens would possibly aid in the reduction of complications. PFA performed in patients with periprosthetic fracture seem to fair better. This study supports the judicious use of PFA in non-oncological revision hip arthroplasties, and that they be performed by experienced revision arthroplasty surgeons. Cite this article: Bone Jt Open 2022;3(3):229–235

Aims. To assess the feasibility of a randomized controlled trial (RCT) that compares three treatments for acetabular fractures in older patients: surgical fixation, surgical fixation and hip arthroplasty (fix-and-replace), and non-surgical treatment. Methods. Patients were recruited from seven UK NHS centres and randomized to a three-arm pilot trial if aged older than 60 years and had a displaced acetabular fracture. Feasibility outcomes included patients’ willingness to participate, clinicians’ capability to recruit, and dropout rates. The primary clinical outcome measure was the EuroQol five-dimension questionnaire (EQ-5D) at six months. Secondary outcomes were Oxford Hip Score, Disability Rating Index, blood loss, and radiological and mobility assessments. Results. Between December 2017 and December 2019, 60 patients were recruited (median age 77.4 years, range 63.3 to 88.5) (39/21 M/F ratio). At final nine-month follow-up, 4/60 (7%) had withdrawn, 4/60 (7%) had died, and one had been lost to follow-up; a 98% response rate (50/51) was achieved for the EQ-5D questionnaire. Four deaths were recorded during the three-year trial period: three in the non-surgical treatment group and one in the fix-and-replace group. Conclusion. This study has shown a full-scale RCT to be feasible, but will need international recruitment. The Acetabular Fractures in older patients Intervention Trial (AceFIT) has informed the design of a multinational RCT sample size of 1,474 or 1,974 patients for a minimal clinically important difference of 0.06 on EQ-5D, with a power of 0.8 or 0.9, and loss to follow-up of 20%. This observed patient cohort comprises a medically complex group requiring multidisciplinary care; surgeon, anaesthetist, and ortho-geriatrician input is needed to optimize recovery and rehabilitation. Cite this article: Bone Joint J 2024;106-B(4):401–411

The aim of this study was to systemically review the evidence for the use of intra-operative cell salvage (ICS) among patients undergoing revision hip arthroplasty, and synthesis the available data to quantify any associated reduction in allogeneic blood transfusion. An electronic database search of MEDLINE (PubMed), EMBASE, Scopus and the Cochrane Library was completed from the date of inception to 9. th. February 2021, using a search strategy and protocol created in conjunction with the PRISMA statement. Inclusion criteria were (i) adult patients >18 years, (ii) ICS utilised in one study group, (iii) revision hip arthroplasty performed. Exclusion criteria were (i) pre-donation of red blood cells, (ii) mixed reporting without dedicated subgroup analysis for revision hip arthroplasty. Screening for eligibility, and quality assessment of included studies, was performed independently by two authors (TW and DH), and any disputes settled by third author (AK). Of the 187 records identified, 11 studies were included in the qualitative analysis, and 5 studies suitable for quantitative meta-analysis. Across the included studies there were 1856 participants, with a mean age of 63.86 years and a male: female ratio of 0.90. Quality assessment demonstrated low or medium risk of bias only. For revision hip arthroplasty patients receiving ICS, 37.07% required ABT with a mean transfusion of 1.92 units or 385ml per patient. For patients treated without ICS, 64.58% required ABT with a mean transfusion of 4.02 units or 803ml per patient. This difference achieved statistical significance (p < 0.05). This study has demonstrated a significant reduction in the need for allogenic blood transfusion associated with intra-operative cell salvage use among patients undergoing revision hip arthroplasty. This study therefore supports the routine use of ICS in this patient group. However, a major limitation is the lack of clinical outcomes reported by the available studies. Further research is required to determine whether this effect is associated with sub-groups of revision arthroplasty procedure, and whether ICS impacts clinical outcomes such as length of stay, rehabilitation progress and mortality

The October 2023 Hip & Pelvis Roundup. 360. looks at: Femoroacetabular impingement syndrome at ten years – how do athletes do?; Venous thromboembolism in patients following total joint replacement: are transfusions to blame?; What changes in pelvic sagittal tilt occur 20 years after total hip arthroplasty?; Can stratified care in hip arthroscopy predict successful and unsuccessful outcomes?; Hip replacement into your nineties; Can large language models help with follow-up?; The most taxing of revisions – proximal femoral replacement for periprosthetic joint infection – what’s the benefit of dual mobility?

Aims. In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Methods. Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years). Results. In the DM group, two (3.8%) patients underwent further surgery: one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (9.8%) underwent further procedures: two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operating time (68.4 vs 101.5 mins, p < 0.001), postoperative drop in haemoglobin (16.6 vs 27.8 g/L, p < 0.001), and length of stay (1.8 vs 2.4 days, p < 0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p < 0.001), although there was no difference between groups for this reduction (p = 0.674 (cobalt); p = 0.186 (chromium)). Conclusion. In selected patients with Birmingham MoM hips, where the acetabular component is well-fixed and in a satisfactory position with no surface damage, the metal head can be exchanged for polyethylene ADM/MDM bearings with retention of the acetabular prosthesis. This presents significant benefits, with a shorter procedure and a lower risk of complications. Cite this article: Bone Jt Open 2024;5(6):514–523

Aims. Acetabular edge-loading was a cause of increased wear rates in metal-on-metal hip arthroplasties, ultimately contributing to their failure. Although such wear patterns have been regularly reported in retrieval analyses, this study aimed to determine their in vivo location and investigate their relationship with acetabular component positioning. Methods. 3D CT imaging was combined with a recently validated method of mapping bearing surface wear in retrieved hip implants. The asymmetrical stabilizing fins of Birmingham hip replacements (BHRs) allowed the co-registration of their acetabular wear maps and their computational models, segmented from CT scans. The in vivo location of edge-wear was measured within a standardized coordinate system, defined using the anterior pelvic plane. Results. Edge-wear was found predominantly along the superior acetabular edge in all cases, while its median location was 8° (interquartile range (IQR) -59° to 25°) within the anterosuperior quadrant. The deepest point of these scars had a median location of 16° (IQR -58° to 26°), which was statistically comparable to their centres (p = 0.496). Edge-wear was in closer proximity to the superior apex of the cups with greater angles of acetabular inclination, while a greater degree of anteversion influenced a more anteriorly centred scar. Conclusion. The anterosuperior location of edge-wear was comparable to the degradation patterns observed in acetabular cartilage, supporting previous findings that hip joint forces are directed anteriorly during a greater portion of walking gait. The further application of this novel method could improve the current definition of optimal and safe acetabular component positioning. Cite this article: Bone Joint Res 2021;10(10):639–649

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. There is an increasing demand for hip arthroplasty in China. We aimed to describe trends in in-hospital mortality after this procedure in China and to examine the potential risk factors. Patients and Methods. We included 210 450 patients undergoing primary hip arthroplasty registered in the Hospital Quality Monitoring System in China between 2013 and 2016. In-hospital mortality after hip arthroplasty and its relation to potential risk factors were assessed using multivariable Poisson regression. Results. During the study period, 626 inpatient deaths occurred within 30 days after hip arthroplasty. Mortality decreased from 2.9% in 2013 to 2.6% in 2016 (p for trend = 0.02). Compared with their counterparts, old age, male sex, and divorced or widowed patients had a higher rate of mortality (all p < 0.05). Risk ratio (RR) for mortality after arthroplasty for fracture was two-fold higher (RR 2.0, 95% confidence interval (CI) 1.5 to 2.6) than that for chronic disease. RRs for mortality were 3.3 (95% CI 2.7 to 3.9) and 8.2 (95% CI 6.5 to 10.4) for patients with Charlson Comorbidity Index (CCI) of 1 to 2 and CCI ≥ 3, respectively, compared with patients with CCI of 0. The rate of mortality varied according to geographical region, the lowest being in the East region (1.8%), followed by Beijing (2.1%), the North (2.9%), South-West (3.6%), South-Central (3.8%), North-East (4.1%), and North-West (5.2%) regions. Conclusion. While in-hospital mortality after hip arthroplasty in China appears low and declined during the study period, discrepancies in mortality after this procedure exist according to sociodemographic factors. Healthcare resources should be allocated more to underdeveloped regions to further reduce mortality. Cite this article: Bone Joint J 2019;101-B:1209–1217

Aims. Total hip arthroplasty (THA) is one of the most successful surgical procedures. The objectives of this study were to define whether there is a correlation between socioeconomic status (SES) and surgical complications after elective primary unilateral THA, and investigate whether access to elective THA differs within SES groups. Methods. We conducted a retrospective, population-based cohort study involving 202 hospitals in Ontario, Canada, over a 17-year period. Patients were divided into income quintiles based on postal codes as a proxy for personal economic status. Multivariable logistic regression models were then used to primarily assess the relationship between SES and surgical complications within one year of index THA. Results. Of 111,359 patients who underwent elective primary THA, those in the lower SES groups had statistically significantly more comorbidities and statistically significantly more postoperative complications. While there was no increase in readmission rates within 90 days, there was a statistically significant difference in the primary and secondary outcomes including all revisions due (with a subset of deep wound infection and dislocation). Results showed that those in the higher SES groups had proportionally more cases performed than those in lower groups. Compared to the highest SES quintile, the lower groups had 61% of the number of hip arthroplasties performed. Conclusion. Patients in lower socioeconomic groups have more comorbidities, fewer absolute number of cases performed, have their procedures performed in lower-volume centres, and ultimately have higher rates of complications. This lack of access and higher rates of complications is a “double hit” to those in lower SES groups, and indicates that we should be concentrating efforts to improve access to surgeons and hospitals where arthroplasty is routinely performed in high numbers. Even in a universal healthcare system where there are no penalties for complications such as readmission, there seems to be an inequality in the access to THA. Cite this article: Bone Joint J 2022;104-B(5):589–597

The rising prevalence of osteoarthritis, associated with an ageing population, is expected to deliver increasing demand across Scotland for arthroplasty services in the future. Understanding the scale of potential change to operative workflow is essential to ensure adequate provision of services and prevent prolonged waiting times that can cause patient harm. This future service demand for primary and revision hip arthroplasty across Scotland, and the rest of the U.K., is hitherto unknown. We set out to provide projections of future primary & revision hip arthroplasty out to 2038 utilising historical trend data (2008–2018) from the Scottish Arthroplasty Project. All analyses were performed using the Holt's exponential smoothing projection method with the forecast package in R statistics. Results were adjusted for projected future population estimates provided by National Records of Scotland. Independent age & sex group predictions were also performed. All results are presented per 100,000 population at-risk per year (/100k/year). The predicted rise of primary hip arthroplasty for all ages is from 120/100k/year in 2018 to 152/100k/year in 2038, a 27% increase. Based on a static 3 day length of stay average this would see 4280 additional patient bed days required for primary hip arthroplasty patients per annum. The number of revision hip arthroplasty procedures for all ages is projected to fall from 14/100k/year to 4/100k/year based on historical trend data. This does not however take into account the suspect increase in primary arthroplasty numbers that is likely to influence future revision rates. Anticipated future demand for primary hip arthroplasty will require significant additional resource and funding to prevent deterioration in quality of care and an increase in patient wait times. Demand for revision arthroplasty is set to decrease, likely on account of improved implant materials, technique, and understanding of best practice to minimise complication risk. This doesn't however take into account the impact of the complex interaction between an increasing primary arthroplasty rate and revision risk. Understanding presented projections of changes to arthroplasty demand is key to future service delivery

Patients may be able to return to higher level activities following hip arthroplasty with modern techniques and prostheses, but the Oxford hip score, the standard PROM used by the NJS exhibits severe skew and kurtosis. The commonest score is 48/48. Most patients score above 40 preventing any discrimination between approaches or prostheses. We therefore sought both subjective and objective metrics which were relevant and valid without skew or high kurtosis in postoperative patients. The Metabolic Equivalent of Task (MET) reports energy usage in kcal/min burnt across a range of activities, condensed into a score of 0–25. A MET over 8 is considered ‘conditioning exercise’ tethered to life expectancy. A 2 point difference in average MET is considered a clinically relevant difference. Walking speed is a simple valid metric tethered to life expectancy, with a 0.1m/sec difference in walking speed equates to a clinically important difference. Oxford Hip Score (OHS), and the MET were prospectively recorded in 221 primary hip arthroplasty procedures pre-operatively and at 1-year using a web based application. Pre and postoperative Gait analysis was undertaken on a subgroup of 34 patients, in comparison with age and sex matched controls. Post-operatively, the OHS demonstrated significant skewed distributions with ceiling effects of 41% scoring 48/48. The MET was normally distributed around a mean of 10.3, with a standard deviation of 3.8 and no ceiling effect. Walking speed was normally distributed around a mean of 1.8m/sec, with a standard deviation was 0.15 m/sec. The MET is a simple patient reported score, which is normally distributed in patients following hip arthroplasty, around a mean of 10.3 with a standard deviation of 3.8. This valid activity metric correlates well with fast walking speed. This is also normally distributed with a standard deviation of over 0.1m/sec confirming low kurtosis. These simple measures have face validity: undertaking less active pastimes and being unable to keep up with other walkers are obviously inadvisable. The normal kurtosis of these metrics suggest that they may able to detect clinically relevant differences in outcome which are undetectable with commonly used PROMs. For surgeons developing less invasive approaches or using novel stems, these measures may detect clinically important improvements undetectable by the Oxford Hip Score

Aims. The aim of this study was to determine satisfaction rates after hip and knee arthroplasty in patients who did not respond to postoperative patient-reported outcome measures (PROMs), characteristics of non-responders, and contact preferences to maximize response rates. Methods. A prospective cohort study of patients planned to undergo hip arthroplasty (n = 713) and knee arthroplasty (n = 737) at a UK university teaching hospital who had completed preoperative PROMs questionnaires, including the EuroQol five-dimension health-related quality of life score, and Oxford Hip Score (OHS) and Oxford Knee Score (OKS). Follow-up questionnaires were sent by post at one year, including satisfaction scoring. Attempts were made to contact patients who did not initially respond. Univariate, logistic regression, and receiver operator curve analysis was performed. Results. At one year, 667 hip patients (93.5%) and 685 knee patients (92.9%) had undergone surgery and were alive. No response was received from 151/667 hip patients (22.6%), 83 (55.0%) of whom were ultimately contacted); or from 108/685 knee patients (15.8%), 91 (84.3%) of whom were ultimately contacted. There was no difference in satisfaction after arthroplasty between initial non-responders and responders for hips (74/81 satisfied vs 476/516 satisfied; p = 0.847) or knees (81/93 satisfied vs 470/561 satisfied; p = 0.480). Initial non-response and persistent non-response was associated with younger age, higher BMIs, and worse preoperative PROMs for both hip and knee patients (p < 0.050). Being in employment was associated with persistent non-response for hip patients (p = 0.047). Multivariate analysis demonstrated that younger age (p < 0.038), higher BMI (p = 0.018), and poorer preoperative OHS (p = 0.031) were independently associated with persistent non-response to hip PROMs. No independent associations were identified for knees. Using a threshold of > 66.4 years predicted a preference for contact by post (area under the curve 0.723 (95% confidence interval (CI) 0.647 to 0.799; p < 0.001, though this CI crosses the 0.7 limit considered reliable). Conclusion. The majority of initial non-responders were ultimately contactable with effort. Satisfaction rates were not inferior in patients who did not initially respond to PROMs. Cite this article: Bone Jt Open 2022;3(4):275–283

Objectives. We used the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR) to investigate the risk of revision due to prosthetic joint infection (PJI) for patients undergoing primary and revision hip arthroplasty, the changes in risk over time, and the overall burden created by PJI. Methods. We analysed revision total hip arthroplasties (THAs) performed due to a diagnosis of PJI and the linked index procedures recorded in the NJR between 2003 and 2014. The cohort analysed consisted of 623 253 index primary hip arthroplasties, 63 222 index revision hip arthroplasties and 7585 revision THAs performed due to a diagnosis of PJI. The prevalence, cumulative incidence functions and the burden of PJI (total procedures) were calculated. Overall linear trends were investigated with log-linear regression. Results. We demonstrated a prevalence of revision THA due to prosthetic joint infection of 0.4/100 procedures following primary and 1.6/100 procedures following revision hip arthroplasty. The prevalence of revision due to PJI in the three months following primary hip arthroplasty has risen 2.3-fold (95% confidence interval (CI) 1.3 to 4.1) between 2005 and 2013, and 3.0-fold (95% CI 1.1 to 8.5) following revision hip arthroplasty. Over 1000 procedures are performed annually as a consequence of hip PJI, an increase of 2.6-fold between 2005 and 2013. Conclusions. Although the risk of revision due to PJI following hip arthroplasty is low, it is rising and, coupled with the established and further predicted increased incidence of both primary and revision hip arthroplasty, this represents a growing and substantial treatment burden. Cite this article: E. Lenguerrand, M. R. Whitehouse, A. D. Beswick, S. A. Jones, M. L. Porter, A. W. Blom. Revision for prosthetic joint infection following hip arthroplasty: Evidence from the National Joint Registry. Bone Joint Res 2017;6:391–398. DOI: 10.1302/2046-3758.66.BJR-2017-0003.R1

Increased collection of patient-reported outcome measures (PROM) in registries enables international comparison of patient-centered outcomes after knee and hip replacement. We aimed to investigate 1) variations in PROM improvement, 2) the possible confounding factor of BMI, and 3) differences in comorbidity distributions between registries. Registries affiliated with the International Society of Arthroplasty Registries (ISAR) or OECD membership countries were invited to report aggregate EQ-5D, OKS, OHS, HOOS-PS and KOOS-PS values. Eligible patients underwent primary total, unilateral knee or hip replacement for osteoarthritis within three years and had completed PROMs preoperatively and either 6 or 12 months postoperatively, excluding patients with subsequent revisions. For each PROM cohort, Chi-square tests were performed for BMI distributions across registries and 12 predefined PROM strata (male/female, age 20-64/65-74/>75, high or low preoperative PROM scores). Comorbidity distributions were reported for available comorbidity indexes. Thirteen registries from 9 countries contributed data, n~130000 knee (range 140 to 79848) and n~113000 hip (range 137 to 85281). Mean EQ-5D index values (10 registries) ranged from 0.53 to 0.71 (knee) and 0.50 to 0.70 (hips) preoperatively and 0.78 to 0.85 (knee) and 0.83 to 0.87 (hip) postoperatively. Mean OKS (6 registries) ranged from 19.3 to 23.6 preoperatively and 36.2 to 41.2 postoperatively. Mean OHS (7 registries) ranged from 18.0 to 23.2 preoperatively and 39.8 to 44.2 postoperatively. Four registries reported KOOS-PS and three reported HOOS-PS. Proportions of patients with BMI >30 ranged from 35 to 62% (10 knee registries) and 16 to 43% (11 hip registries). For both knee and hip registries, distributions of patients across six BMI categories differed significantly among registries (p30 were for patients in the youngest age groups (20 to 64 and 65 to 74 years) with the lowest baseline scores. Additionally, females with lowest preoperative PROM scores had highest BMI. These findings were echoed for the OHS and OKS cohorts. Proportions of patients with ASA scores ≥3 ranged from 7 to 42% (9 knee registries) and 6 to 35% (8 hip registries). PROM-score improvement varies between international registries, which may be partially explained by differences in age, sex and preoperative scores. BMI and comorbidity may be relevant to adjust for

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

Obesity is a known risk factor for hip osteoarthritis. The aim of this study was to compare the incidence of obesity in Australians undergoing hip replacements (HR) for osteoarthritis to the general population. A cohort study was conducted comparing data from the Australian Bureau of Statistics and the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 2017-18. Body mass index (BMI) data for patients undergoing primary total hip replacement and resurfacing for osteoarthritis were obtained from the AOANJRR. The distribution of HR patients by BMI category was compared to the general population, in age and sex sub-groups. During the study period, 32,495 primary HR were performed for osteoarthritis in Australia. Compared to the general population, there was a higher incidence of Class I, II, and III obesity in patients undergoing HR in both sexes aged 35 to 74 years old. Class III obese females and males undergoing HR were on average 6 to 7 years younger than their normal weight counterparts. Class III obese females and males aged 55-64 years old were 2.9 and 1.7 times more likely to undergo HR, respectively (p<0.001). There is a strong association between increased BMI and relative risk of undergoing HR. Similar findings have been noted in the United States of America, Canada, United Kingdom, Sweden and Spain. A New Zealand Registry study and recent meta-analysis have also found a concerning trend of Class III obese patients undergoing HR at a younger age. Obese Australians are at increased risk of undergoing HR at a younger age. A national approach to address the prevalence of obesity is needed

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

Ideally the hip arthroplasty should not be subject to bony or prosthetic impingement, in order to minimise complications and optimise outcomes. Modern 3d planning permits pre-operative simulation of the movements of the planned hip arthroplasty to check for such impingement. For this to be meaningful, however, it is necessary to know the range of movement (ROM) that should be simulated. Arbitrary “normal” values for hip ROM are of limited value in such simulations: it is well known that hip ROM is individualised for each patient. We have therefore developed a method to determine this individualised ROM using CT scans. CT scans were performed on 14 cadaveric hips, and the images were segmented to create 3d virtual models. Using Matlab software, each virtual hip was moved in all potential directions to the point of bony impingement, thus defining an individualised impingement-free 3d ROM envelope. This was then compared with the actual ROM as directly measured from each cadaver using a high-resolution motion capture system. For each hip, the ROM envelope free of bony impingement could be described from the CT and represented as a 3d shape. As expected, the directly measured ROM from the cadaver study for each hip was smaller than the CT-based prediction, owing to the presence of constraining soft tissues. However, for movements associated with hip dislocation (such as flexion with internal rotation), the cadaver measurements matched the CT prediction, to within 10°. It is possible to determine an individual's range of clinically important hip movements from a CT scan. This method could therefore be used to create truly personalised movement simulation as part of pre-operative 3d surgical planning

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. Despite advances in the treatment of paediatric hip disease, adolescent and young adult patients can develop early onset end-stage osteoarthritis. The aims of this study were to address the indications and medium-term outcomes for total hip arthroplasty (THA) with ceramic bearings for teenage patients. Methods. Surgery was performed by a single surgeon working in the paediatric orthopaedic unit of a tertiary referral hospital. Databases were interrogated from 2003 to 2017 for all teenage patients undergoing THA with a minimum 2.3 year follow-up. Data capture included patient demographics, the underlying hip pathology, number of previous surgeries, and THA prostheses used. Institutional ethical approval was granted to contact patients for prospective clinical outcomes and obtain up-to-date radiographs. In total, 60 primary hips were implanted in 51 patients (35 female, 16 male) with nine bilateral cases. The mean age was 16.7 years (12 to 19) and mean follow-up was 9.3 years (2.3 to 16.8). Results. The most common indication for teenage hip arthroplasty was avascular necrosis secondary to slipped upper femoral epiphysis (31%; n = 16). Overall, 64% of patients (n = 33) had undergone multiple previous operations. The survival at follow-up was 97%; two patients required revision for aseptic loosening (one femoral stem, one acetabular component). Both patients had fused hips noted at the time of arthroplasty. A further two patients had radiolucent lines but were asymptomatic. At latest follow-up the mean Oxford Hip Score was 44 (31 to 48) and a Visual Analogue Scale measurement of 1.5, indicating satisfactory function. Conclusion. Operating on this cohort can be complicated by multiple previous surgeries and distorted anatomy, which in some cases require custom-made prostheses. We have demonstrated a good outcome with low revision rate in this complex group of patients. Cite this article: Bone Joint J 2020;102-B(11):1491–1496

Successful estimation of postoperative PROMs prior to a joint replacement surgery is important in deciding the best treatment option for a patient. However, estimation of the outcome is associated with substantial noise around individual prediction. Here, we test whether a classifier neural network can be used to simultaneously estimate postoperative PROMs and uncertainty better than current methods. We perform Oxford hip score (OHS) estimation using data collected by the NJR from 249,634 hip replacement surgeries performed from 2009 to 2018. The root mean square error (RMSE) of the various methods are compared to the standard deviation of outcome change distribution to measure the proportion of the total outcome variability that the model can capture. The area under the curve (AUC) for the probability of the change score being above a certain threshold was also plotted. The proposed classifier NN had a better or equivalent RMSE than all other currently used models. The threshold AUC shows similar results for all methods close to a change score of 20 but demonstrates better accuracy of the classifier neural network close to 0 change and greater than 30 change, showing that the full probability distribution performed by the classifier neural network resulted in a significant improvement in estimating the upper and lower quantiles of the change score probability distribution. Consequently, probabilistic estimation as performed by the classifier NN is the most adequate approach to this problem, since the final score has an important component of uncertainty. This study shows the importance of uncertainty estimation to accompany postoperative PROMs prediction and presents a clinically-meaningful method for personalised outcome that includes such uncertainty estimation

Objectives. Modular dual-mobility (MDM) constructs are used to reduce dislocation rates after total hip replacement (THR). They combine the advantages of dual mobility with the option of supplementary acetabular screw fixation in complex revision surgery. However, there are concerns about adverse reaction to metal debris (ARMD) as a result of fretting corrosion between the metal liner and shell. Methods: The aim of this systematic review was to find and review all relevant studies to establish the outcomes and risks associated with MDM hip replacement. All articles on MDM THRs in the Medline, EMBASE, CINAHL, Cochrane Library, and Prospero databases were searched. A total of 14 articles were included. A random intercept logistic regression model was used for meta-analysis, giving estimated average values. Results: There were 6 cases of ARMD out of 1312 total. Estimated median incidence of ARMD from meta-analysis was 0.3% (95% CI 0.1 – 1.4%). Mean postoperative serum Cobalt was 0.81 μg/L (95% CI 0.33 – 1.29 μg/L), and Chromium was 0.77 μg/L (95% 0.35 – 1.19 μg/L), from 279 cases in 7 studies. Estimated median incidence of a serum cobalt or chromium ion measurement ≥1 μg/L was 7.9% (95% CI 3.5 – 16.8%), and ≥7 μg/L was 1.8% (95% CI 0.7 – 4.2%). Conclusions: ARMD is a rare but significant complication following total hip replacement using a MDM construct. Its incidence appears higher than that reported in non-metal-on-metal (MoM) hip replacements but lower than that of MoM hip replacements. MDM hip replacements are associated with raised serum metal ion levels postoperatively, but there was no correlation with worse clinical hip function within studies. Studies were poor quality and at high risk of confounding. Pending further work, MDM constructs should be used with caution, reserved for select cases at particularly high risk of dislocation

This study investigates the use of the Metabolic Equivalent of Task (MET) score in a hip arthroplasty population and its ability to capture additional benefit beyond the maximum Oxford Hip Score (OHS). OHS, EuroQol-5D index (EQ-5D), and the MET were prospectively recorded in 221 primary hip arthroplasty procedures pre-operatively and at 1-year. The distribution was examined reporting the presence of ceiling & floor effects. Validity was assessed correlating the MET with the other scores using Spearman's rank and determining responsiveness using the standardised response mean (SRM). A subgroup of 93 patients scoring 48/48 on the OHS were analysed by age group, sex, BMI and pre-operative MET using the other two metrics to determine if differences could be established despite all scoring identically on the OHS. 117 total hip and 104 hip resurfacing arthroplasty operations were included. Mean age was 59.4 ± 11.3. Post-operatively the OHS and EQ-5D demonstrate significant negatively skewed distributions with ceiling effects of 41% and 53%, respectively. The MET was normally distributed post-operatively with no ceiling effect. Weak-moderate but statistically significant correlations were found between the MET and the other two metrics both pre & post-operatively. Responsiveness was excellent, SRM for OHS: 2.01, EQ-5D: 1.06 and MET: 1.17. In the 48/48 scoring subgroup, no differences were found comparing groups with the EQ-5D, however significantly higher MET scores were demonstrated for patients aged <60 (12.7 vs 10.6, p=0.008), male patients (12.5 vs 10.8, p=0.024) and those with pre-operative MET scores >6 (12.6 vs 11.0, p=0.040). The MET is normally distributed in patients following hip arthroplasty, recording levels of activity which are undetectable using the OHS. As a simple, valid activity metric, it should be considered in addition to conventional PROMs in order to capture the entire benefit experienced following hip arthroplasty

Abstract. Objectives. Evidence supporting the use of immersive virtual reality (iVR) training in orthopaedic procedures is rapidly growing. However, the impact of the timing of delivery of this training is yet to be tested. This study investigated whether spaced iVR training is more effective than massed iVR training for novices learning hip arthroplasty. Methods. 24 medical students with no hip arthroplasty experience were randomised to learning total hip arthroplasty using the same iVR simulation training either once-weekly or once-daily for four sessions. Participants underwent a baseline physical world assessment to orientate an acetabular component on a saw bone pelvis, and a baseline knowledge test. In iVR, we recorded procedural errors, time, numbers of prompts required and path lengths of the hands and head across 4 sessions. To assess skill retention, the iVR and baseline physical world assessments were repeated at one-week and one-month. Results. Baseline characteristics between the groups were comparable (p > 0.05). The daily group demonstrated faster skills acquisition, reducing the mean number of procedural errors from 76.8±37.5 (S1) to 11.1±10.1 (S4), compared to the weekly group improvement from 71.1±19.1 (S1) to 17.2±10.6 (S4), p < 0.001. The weekly group error count plateaued remaining at 16±6.7 at 1-week and 17.5±8.5 at one-month, the daily group however, showed poor retention with error counts rising to 17.8±10.5 at 1 week and becoming higher than the weekly group at one-month to (23.2±13.0 vs 17.5±10.5). A similar effect was noted for procedural time and the number of assistive prompts. In the real-world assessment, both groups significantly improved the accuracy of their acetabular component positioning, these improvements were equally maintained. Conclusions. Daily iVR training facilitates faster skills acquisition, however weekly practice has superior skills retention. Skills learnt using both regimes demonstrate sustained transfer to the real-world

Abstract. Objective. Short-stem total hip arthroplasty (THA) aims to preserve the proximal bone stock for future revisions, so that the first revision should resemble a primary intervention rather than a revision. This study aimed to compare the clinical and radiological outcomes in revision THA after failed short stem versus after failed conventional stem THA. Methods. This study included forty-five patients with revision THA divided into three groups (15 each); group A: revision after short stem, group B: revision after conventional cementless stem and group C revision after conventional cemented stem. The studied groups were compared regarding 31 variables including demographic data, details of the primary and revision procedures, postoperative radiological subsidence, hospital stay, time for full weight bearing (FWB), preoperative and postoperative clinical scores. Results. Early stem subsidence (40%) was the main indication of revision in group A compared to peri-prosthetic femoral fractures (PFFs) (73.3%) and aseptic loosening (53.3%) in group B and C respectively (P=0.021). The mean time to revision was significantly shorter in group A (15 months) compared to 95.33 and 189.40 months in group B and C respectively. (P=0.005). Sixty % (9 patients) in group A were revised in the first year. The mean operative time, blood loss, postoperative blood transfusion and hospital stay were significantly lower in group A compared to group B and C (P<0.001, <0.001, 0.002 and 0.001 respectively). Revisions in group A were performed using either short stems (13.3%) or conventional stems (86.7%) whilst 80% of patients needed long stems and 20% of patients needed conventional stems in group B and C (P<0.001). The mean postoperative Harris Hip Score (HHS) at the latest follow up was 87.07, 87.53 and 85.47 in group A, B and C respectively. All PFFS had excellent results according to Beal's and Tower's criteria; all fractures healed and the implants were stable. Conclusion. The most common cause of failure of short stems is early stem subsidence. Short stem THA has specific indications and patient selection is very crucial. Preoperative templating for short stems and a detailed analysis of the individual patient anatomy in anteroposterior and lateral views are mandatory to predict the correct implant size more accurately. The use of intraoperative imaging can verify the sizing, implant position, and sufficient contact with the lateral cortex. Revision of short stem THA resembled the primary THA. If a standard implant can be used in a surgical revision instead of a longer revision stem, this can be considered as an advantage for the hip arthroplasty treatment concept. However, this only applies if the longevity of the first treatment with a short stem is comparable with that of a standard stem. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Venous thromboembolism (VTE) is a preventable cause of morbidity and mortality in patients undergoing elective hip arthroplasty surgery. The balance of post-operative VTE prophylaxis and risk of post-operative haemorrhage remains at the forefront of surgeon's mind. The National Institute for Clinical Excellence (NICE) has altered their prophylaxis guidance in the setting of total hip arthroplasty (THA). The aim of this study was to present the VTE incidence in 8,890 patients who underwent total hip arthroplasty between January 1997 and March 2018 with Aspirin as the primary agent for pharmacological thromboprophylaxis. Analysis of prospective data collection from consecutive patients undergoing THA was performed with the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) occurring within 6 months of the index operation as the primary outcome measure. 90-day all-cause mortality of this cohort of patients was also analysed. 8890 patients were reviewed. This included 7235 primary, 224 complex primary and 1431 revision cases. The incidence of DVT was 0.64% after elective THA and the incidence of PE was 0.54%. There was no difference in the incidence between primary and revision cases. The 90-day all-cause mortality was 0.88%. Cardiovascular and respiratory disease were the main causes of death following surgery. Only 0.03% of deaths (n= 3) within 90 days of index surgery were due to VTE. Our results support the use of aspirin as an effective form of prophylaxis against VTE following THA. It is not associated with an increased incidence in symptomatic DVT, PE or death compared to other published studies. The fact that it is inexpensive, readily available, requires no monitoring and does not pose an increased risk of bleeding are other attractive advantages of using aspirin for VTE prophylaxis

Successful estimation of postoperative PROMs prior to a joint replacement surgery is important in deciding the best treatment option for a patient. However, estimation of the outcome is associated with substantial noise around individual prediction. Here, we test whether a classifier neural network can be used to simultaneously estimate postoperative PROMs and uncertainty better than current methods. We perform Oxford hip score (OHS) estimation using data collected by the NJR from 249,634 hip replacement surgeries performed from 2009 to 2018. The root mean square error (RMSE) of the various methods are compared to the standard deviation of outcome change distribution to measure the proportion of the total outcome variability that the model can capture. The area under the curve (AUC) for the probability of the change score being above a certain threshold was also plotted. The proposed classifier NN had a better or equivalent RMSE than all other currently used models. The standard deviation for the change score for the entire population was 9.93, which can be interpreted as the RMSE that would be achieved for a model that gives the same estimation for all patients regardless of the covariates. However, most of the variation in the postoperative OHS/OKS change score is not captured by the models, confirming the importance of accurate uncertainty estimation. The threshold AUC shows similar results for all methods close to a change score of 20 but demonstrates better accuracy of the classifier neural network close to 0 change and greater than 30 change, showing that the full probability distribution performed by the classifier neural network resulted in a significant improvement in estimating the upper and lower quantiles of the change score probability distribution. Consequently, probabilistic estimation as performed by the classifier NN is the most adequate approach to this problem, since the final score has an important component of uncertainty. This study shows the importance of uncertainty estimation to accompany postoperative PROMs prediction and presents a clinically-meaningful method for personalised outcome that includes such uncertainty estimation

Introduction. Total knee and hip arthroplasty were the main arthroplasty surgery performed in Brazil. In Brazil, around 50% of arthroplasty surgeries are performed by the public health system, knowing as SUS . 1. SUS is the biggest public and universal health system in the world, attending 100% of the Brazilian population (220 million), with 2020's expected budget of US$ 31 billion . 2,3. . The National Institute of Clinical Excellence utilizes the QALY system (Quality adjustment year life)to calculate the best cost-benefit between medical interventions . 4. In compliance with the study, an operated person has a QALY index of £5000 while a non-operated person has an index of £7182. In March 2020, due to the COVID-19 pandemics, the Brazilian Health Ministry oriented for the postponing of elective surgery, to prioritize combating the virus . 5. This postponing, it was important but will cause an impact in the economy at the public health system from Brazil this year and in the next years. Therefore, this study aims to present the economic impact caused by COVID-19 pandemics in the public heal system, SUS, of Brazil. Methods. Data about total hip arthroplasty (THA) and total knee arthroplasty (TKA) in Brazil were collected from the TABNET portal of the Brazilian Health Ministry/Datasus . 6. It was collected information per month about hospitalization authorization (AIH), and total cost per AIH. The information regards the period of January to June from years 2015 to 2020. Results and Discussion. After the orientation in march 2020 to postpone elective surgery, there was a reduction of up to 91% in total knee arthroplasty (TKA) and 76% in total hip arthroplasty (THA), compared to the same period in the previous years (see Figure 1). This represents a reduction of more than 5000 surgeries in the first semester. According to Brazilian doctors, the retention of surgeries will result in excessive demand for the sector in the upcoming months . 7. . Due to the reduction of the AIH, which occurs a reduction US$3,881,494 of the budget destined for arthroplasty surgeries in the first semester of 2020 (see Figure 2), being used to the combat of COVID-19. Consequently, the purchase of new hip and knee prostheses decreases, harming the implant sales sector in Brazil. Furthermore, by the QALY system, the cost of a non-operated patient is up to 43% bigger than that of an operated patient. Thus, this will generate an increase in the expenses of the SUS in the upcoming months or years. Conclusion. The COVID-19 pandemics generate the need of postponing elective surgery of the SUS, such as total hip and knee arthroplasty. Because of this, there was a reduction of 67% of the number and expense of knee and hip arthroplasties in the first semester of 2020. This generates an economic loss for the implants companies and it will increase overly the demand for new surgeries in the upcoming months or years. For any figures or tables, please contact the authors directly

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

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 replacement for aseptic loosening. We conducted a cohort study of first-time, single-stage revision hip replacements (RHR) 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. Among 12,676 RHR 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 RHR (Hazard Ratio (HR) 1·58 (95%CI 1·16 to 2·15)) and remained significantly elevated for their first 26 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. RHR performed at hospitals which had cumulatively undertaken fewer than 168 RHR were at up to 70% greater risk of re-revision (HR 1·70 (95% CI 1·12 to 2·60)), and those having undertaken fewer than 309 RHR were at up to three times greater risk of 90-day mortality (HR 3·06 (95% CI 1·19 to 7·86)). This study found a significantly higher risk of re-revision and early postoperative mortality following first-time single-stage RHR for aseptic loosening when performed by lower-volume consultants and at lower-volume institutions, supporting the move towards the centralisation of such cases towards higher-volume units and surgeons

Ceramic bearings have several desirable properties, such as resistance to wear, hardness, and biocompatibility, that favour it as an articulating surface in hip arthroplasty. However, ceramic fracture remains a concern. We have reviewed the contemporary literature, addressing the factors that can influence the incidence of ceramic bearing surface fracture. Cite this article: Bone Joint J 2019;101-B:897–901

Aims

Manual impaction, with a mallet and introducer, remains the standard method of installing cementless acetabular cups during total hip arthroplasty (THA). This study aims to quantify the accuracy and precision of manual impaction strikes during the seating of an acetabular component. This understanding aims to help improve impaction surgical techniques and inform the development of future technologies.

Aims. In countries with social healthcare systems, such as Canada, patients may experience long wait times and a decline in their health status prior to their operation. The aim of this study is to explore the association between long preoperative wait times (WT) and acute hospital length of stay (LoS) for primary arthroplasty of the knee and hip. Methods. The study population was obtained from the provincial Patient Access Registry Nova Scotia (PARNS) and the Canadian national hospital Discharge Access Database (DAD). We included primary total knee and hip arthroplasties (TKA, THA) between 2011 and 2017. Patients waiting longer than the recommended 180 days Canadian national standard were compared to patients waiting equal or less than the standard WT. The primary outcome measure was acute LoS postoperatively. Secondarily, patient demographics, comorbidities, and perioperative parameters were correlated with LoS with multivariate regression. Results. A total of 11,833 TKAs and 6,627 THAs were included in the study. Mean WT for TKA was 348 days (1 to 3,605) with mean LoS of 3.6 days (1 to 98). Mean WT for THA was 267 days (1 to 2,015) with mean LoS of 4.0 days (1 to 143). There was a significant increase in mean LoS for TKA waiting longer than 180 days (2.5% (SE 1.1); p = 0.028). There was no significant association for THA. Age, sex, surgical year, admittance from home, rural residence, household income, hospital facility, the need for blood transfusion, and comorbidities were all found to influence LoS. Conclusion. Surgical WT longer than 180 days resulted in increased acute LoS for primary TKA. Meeting a shorter WT target may be cost-saving in a social healthcare system by having shorter LoS. Cite this article: Bone Jt Open 2021;2(8):679–684

Total knee and hip arthroplasty (TKA and THA) are two of the highest volume and resource intensive surgical procedures. Key drivers of the cost of surgical care are duration of surgery (DOS) and postoperative inpatient length of stay (LOS). The ability to predict TKA and THA DOS and LOS has substantial implications for hospital finances, scheduling and resource allocation. The goal of this study was to predict DOS and LOS for elective unilateral TKAs and THAs using machine learning models (MLMs) constructed on preoperative patient factors using a large North American database. The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for elective unilateral TKA and THA procedures from 2014-2019. The dataset was split into training, validation and testing based on year. Multiple conventional and deep MLMs such as linear, tree-based and multilayer perceptrons (MLPs) were constructed. The models with best performance on the validation set were evaluated on the testing set. Models were evaluated according to 1) mean squared error (MSE), 2) buffer accuracy (the number of times the predicted target was within a predesignated buffer of the actual target), and 3) classification accuracy (the number of times the correct class was predicted by the models). To ensure useful predictions, the results of the models were compared to a mean regressor. A total of 499,432 patients (TKA 302,490; THA 196,942) were included. The MLP models had the best MSEs and accuracy across both TKA and THA patients. During testing, the TKA MSEs for DOS and LOS were 0.893 and 0.688 while the THA MSEs for DOS and LOS were 0.895 and 0.691. The TKA DOS 30-minute buffer accuracy and ≤120 min, >120 min classification accuracy were 78.8% and 88.3%, while the TKA LOS 1-day buffer accuracy and ≤2 days, >2 days classification accuracy were 75.2% and 76.1%. The THA DOS 30-minute buffer accuracy and ≤120 min, >120 min classification accuracy were 81.6% and 91.4%, while the THA LOS 1-day buffer accuracy and ≤2 days, >2 days classification accuracy were 78.3% and 80.4%. All models across both TKA and THA patients were more accurate than the mean regressors for both DOS and LOS predictions across both buffer and classification accuracies. Conventional and deep MLMs have been effectively implemented to predict the DOS and LOS of elective unilateral TKA and THA patients based on preoperative patient factors using a large North American database with a high level of accuracy. Future work should include using operational factors to further refine these models and improve predictive accuracy. Results of this work will allow institutions to optimize their resource allocation, reduce costs and improve surgical scheduling. Acknowledgements:. The American College of Surgeons National Surgical Quality Improvement Program and the hospitals participating in the ACS NSQIP are the source of the data used herein; they have not verified and are not responsible for the statistical validity of the data analysis or the conclusions derived by the authors

Introduction and Aims. There are many surgical, implant design and patient factors that should be considered in preclinical testing of hip replacement which are not being considered in current standards. The aim of this study was to develop a preclinical testing method that consider surgical positioning, implant design and patient factors and predict the occurrence and severity of edge loading under the combination of such conditions. Then, assess the safety and reliability of the implant by predicting the wear, deformation and damage of the implant bearings under worst case conditions. Methods. Ceramic-on-ceramic (CoC, 36mm, BIOLOX. ®. delta, Pinnacle. ®. , DePuy Synthes, UK) and metal-on polyethylene (MoP, 36mm, Marathon®, Pinnacle. ®. , DePuy Synthes, UK) bearings were used for this study on multi-station multi-axis hip joint simulators. Two factors were varied, cup inclination angles (45° and 65°) and translational mismatch between the femoral head and acetabular cup (0, 2, 3 and 4 (mm)). Under each condition for both CoC and MoP bearings, three million cycles of gait cycle testing were completed with wear, deformation and/or damage measurements completed at one million cycle intervals. Other outputs of the study were the level of dynamic separation between the femoral head and acetabular cup during gait, the maximum force at the rim during edge loading when the head was sliding back to the cup confinement. Means and 95% confidence limits were determined and statistical analysis were done using one way ANOVA with significance taken at p<0.05. Results. As the level of mismatch and the cup inclination angle increased, the magnitude of dynamic separation and the force at the rim increased. The level of dynamic separation and the force on the rim correlated with the wear of CoC bearings (R= 0.96). For polyethylene, steeper inclination angle did not significantly increase the wear (p>0.05) however, edge loading under 4mm translational mismatch and steep cup inclination angle did (p<0.01). The combined wear and deformation of the polyethylene liners at the rim increased under larger levels of dynamic separation. Conclusions. The magnitude of dynamic separation and force at the rim were predictive of the severity of edge loading. These parameters can be measured using short term testing (500 cycles). This will determine the effect of variations in surgical positioning, implant design and patient factors on the occurrence and severity of edge loading. Then, the wear, deformation and/or damage on hip replacement bearings can be determined using longer term simulator testing under selected conditions. The short term tests do not only help identify worst case scenarios but may identify the boundary of surgical position under which the implants performance may be considered acceptable. A new approach for preclinical testing of hip replacement was developed:. Stage 1: Short biomechanical tests. : assess the occurrence and severity of edge loading conditions where the outputs are:. Magnitude of medial-lateral dynamic separation. Maximum force under edge loading. Stage 2: Wear assessment. : assess the tribological performance of hip replacement under selected conditions where the outputs are:. Wear rates. Deformation and/or damage on the bearing surface

Periprosthetic femoral fracture (PFF) incidence following hip replacement surgery continues to rise. There is a national drive to centralise PFF treatment within specialist centres to improve clinical outcomes and cost-effectiveness. The financial implications of treating PFFs must be analysed to guide allocation of funding. Data were collected for 129 PFFs admitted from 02/04/2014–19/05/2020. Financial data were provided by the Patient Level Information and Costing Systems (PLICS) team. Primary outcomes were cost, revenue and margin for each PFF. Additional data were collected on length of stay (LOS), critical care requirements and clinical outcomes. Statistical comparisons were made between treatment type (fixation vs revision). Significance was set to p<0.05. Across the entire cohort, total cost was £2,389,901, total revenue was £1,695,435 and total loss was £694,481. Highest costs were ward stay (£714,591), theatre utilisation (£382,625), and overheads (£249,110). Median cost was £15,863 (IQR, £11,092-£22,221), median revenue was £11,305 (IQR, £7,147-£15,222) and median loss was £3,795 (IQR, £605-£8687). Median LOS was 21 days (IQR 13–34) and 28.7% patients required critical care admission. Ninety-six patients were treated operatively with either fixation (n=53) or revision (n=43). Median operating time was lower for fixation versus revision (132 [IQR, 115–185] vs 201 [IQR, 159–229] minutes, p=0.001). Median cost (£17,455 [IQR, £13,095-£22,824] vs £17,399 [£13,394-£23,404]) and median loss (£5,774 [IQR, £2,092-£10,472] vs £3,860 [IQR, £96-£7,601]) were similar for fixation and revision (p=0.99 and p=0.18, respectively). Median revenue was greater for revision versus fixation (£13,925 [IQR, £11,294-£17,037] vs £12,160 [IQR, £8,486-£14,390], p=0.02). There was no difference in LOS (21 [13–34] vs 21 [14–30] days, p=0.94), critical care requirements (20 [37.7%] vs 11 [25.6%], p=0.30), reoperations (3 [5.7%] vs 6 [14.0%], p=0.29], local complications (8 [15.1%) vs 12 [27.9%], p=0.20) or systemic complications (11 [20.8%] vs 11 [25.6%], p=0.75) between fixation and revision. PFF treatment costs are high with inadequate reimbursement through tariff. Work is needed to address this disparity and reduce costs associated with LOS, theatre utilisation and implants. Treatment cost should not be used when deciding between fixation and revision surgery

The Swedish Hip Arthroplasty Register started in 1979 and celebrates its 40. th. anniversary in 2019. The Swedish Hip Arthroplasty Register is not primarily a device register or research database; we strive to provide an overall assessment of the care provided with a multidimensional approach, and to disseminate knowledge on best practices in our network of participating hospitals. Since the inception of the register, there has been a marked change in trends and outcomes. The completeness of registrations has been 97–99% for primary THA, 93–95% for revisions, and 95–98% for HA over the last 10 years. The register contains 371,125 primary THAs, 55,893 HAs, 83,233 reoperations, and 408,110 PROM responses registered in 352,585 unique patients. All outcome measures have improved over time; primary THA has 0.71% 90-day mortality, 94.3% 10-year implant survival, and 2.2% 2-year reoperation rate. At 1-year follow up, 91% of the patients report a clinically significant pain reduction, 76% report a substantial improvement in health-related quality of life, and 89% are satisfied with the result of the operation. Moving forward, we are developing enhanced online applications for surgeons, patients and the implant industry to access real-time information. This work involves constructing a shared decision-making tool that helps clinicians assessing the future benefits and risks of THA by offering individualized outcome predictions. Further steps forward include randomized clinical trials and nested studies through the registry's platform. The trends and changes in Swedish arthroplasty practice have largely been promoted and facilitated by the register over the last 40 years

Aims. Joint arthroplasties may be associated with a blood loss, which necessitates transfusion. Especially, hip arthroplasties are highly associate with transfusion to compensate perioperative bleeding. Orthopaedic surgeons and patients have increasing concerns regarding complications of blood transfusions. Although various methods to reduce transfusions have been attempted in TJA, a high percentage of patients require a transfusion during and after the procedures. The purposes of this study were to evaluate the trends of the transfusion(transfusion rates, transfusion amounts, economic burden) in hip arthroplasties, using nationwide data from the National Health Insurance Service (NHIS). Patients and methods. We used data from nationwide claims database of Health Insurance Review Assessment Service (HIRA). The data managed by the NHIS were used to identify the 161,934 hip arthroplasties by 3 categories including bipolar hemiarthroplasty(BH), total hip arthroplasty(THA), and revision arthroplasty(RA) from 2007 to 2015. These 3 categories were classified using the operation code recorded in the requisition data of NHIS. The transfusion rates, transfusion amounts, proportion of transfusion, cost of each type of operation was investigated and stratified by age, gender, hospital type, and area in hip arthroplasties. The proportion of transfusion about whole blood, red blood cell, fresh frozen plasma, platelet, was also evaluated in hip arthroplasties. Results. The patients of hip arthroplasties who receive transfusion was observed 11,224/13,584 in 2007, 12,823/15,325 in 2008, 13,447/16.144 in 2009, 14,915/17,702 in 2010, 15,623/18,648 in 2011, 16,374/19,878 in 2012, 16,961/20,423 in 2013, 16,367/20,060 in 2014 and 16,116/20,170 in 2015. Total transfusion rate was 81.1% in 9 years data.(82.6% in 2007, 83.7% in 2008, 83.3% in 2009, 84.3% in 2010, 83.8% in 2011, 82.4% in 2012, 83% in 2013, 81.6% in 2014, 79.9% in 2015. The overall proportion of transfusion was 7% fresh frozen plasma, 12% platelet, and 77% RBC. The total amount of transfusion was 47,351 in 2007, 56.387 in 2008, 58,320 in 2009, 66,604 in 2010, 68,472 in 2011, 74,735 in 2012, 73,370 in 2013, 67,736 in 2014, and 62,749 in 2015. The average dose of transfusion is 4.1 times in bipolar hemiarthroplasty(343,815/ 83,729), 8.7 times in revision arthroplasty(35,044/4,024), 4.3 times in total hip arthroplasty from 2007 to 2015. Conclusion. In this nationally representative study of patterns of transfusion use in hip arthroplasty, we observed relatively high rates in the use of blood transfusion among patients undergoing hip arthroplasties regardless of many factors including patient, hospital, characteristics, compared with researches in other countries. The total amount of transfusion shows decreasing trends recently, however, it does not seem a big difference in transfusion rate

Aims

For the increasing number of working-age patients undergoing total hip or total knee arthroplasty (THA/TKA), return to work (RTW) after surgery is crucial. We investigated the association between occupational class and time to RTW after THA or TKA.

Introduction. Patients with osteonecrosis of the femoral head are typically younger, more active, and often require high rates of revision following primary total hip arthroplasty. However, outcomes of revision hip arthroplasty in this patient population have been rarely reported in the literature. The purpose of this study was to report the intermediate-term clinical and radiographic outcomes of revision hip arthroplasty in patients with osteonecrosis of the femoral head. Materials & Methods. Between November 1994 and December 2009, 187 revision hip arthoplasty were performed in 137 patients who had a diagnosis of osteonecrosis of the femoral head. Exclusion criteria included infection, recurrent instability, isolated polyethylene liner exchange, and inadequate follow-up (less than 3 years). The final study cohort of this retrospective review consisted of 72 patients (75 hips) with a mean age of 53.3 years (range, 34 to 76). Components used for the acetabular revision included a cementless porous-coated cup in 58 hips and an acetabular cage in 2 hips. Components used for the femoral revision included a fully grit-blasted tapered stem in 30 hips and a proximally porous-coated modular stem in 9 hips. The mean duration of follow-up was 7 years (range, 3 to 17). Results. Mean Harris hip score improved 49 points preoperatively to 90 points. At the time of final follow-up, 11 hips (14.7%) patients required additional reoperation procedure. Of these, six for aseptic loosening of acetabular cup and/or femoral stem, two for deep infection, one for recurrent dislocation, one for periprosthetic femoral fracture, and one for ceramic head fracture. Kaplan-Meier survivorship with an end point for cup revision for aseptic loosening was 98.4% at 5 years, 93.4% at 10 years, and with an end point for stem revision for aseptic loosening was 100% at 5 years, 97.4% at 10 years (Fig. 1). Conclusions. Unlike the previous report, our study showed lower failure rate of femoral stem after revision hip arthroplasty using modern cementless femoral components in patients with osteonecrosis of the femoral head. Aseptic cup loosening or osteolysis is the most common mechanism of failure at the medium-term follow-up following revision hip arthroplasty in these patients group

The results of hip and knee replacement surgery are generally regarded as positive for patients. Nonetheless, they are both major operations and have recognised complications. We present a review of relevant claims made to the National Health Service Litigation Authority. Between 1995 and 2010 there were 1004 claims to a value of £41.5 million following hip replacement surgery and 523 claims to a value of £21 million for knee replacement. The most common complaint after hip surgery was related to residual neurological deficit, whereas after knee replacement it was related to infection. Vascular complications resulted in the highest costs per case in each group. Although there has been a large increase in the number of operations performed, there has not been a corresponding relative increase in litigation. The reasons for litigation have remained largely unchanged over time after hip replacement. In the case of knee replacement, although there has been a reduction in claims for infection, there has been an increase in claims for technical errors. There has also been a rise in claims for non-specified dissatisfaction. This information is of value to surgeons and can be used to minimise the potential mismatch between patient expectation, informed consent and outcome. Cite this article: Bone Joint J 2013;95-B:122–6

Introduction. Previous reports have investigated the correlation between time to revision hip arthroplasty (rTHA) and reason for revision, but little is known regarding the impact of timing on outcomes following rTHA. The purpose of this study is to evaluate the effect of time to rTHA on both indication and outcomes of rTHA. Methods. This retrospective observational study reviewed patients who underwent unilateral, aseptic rTHA at an academic orthopedic specialty hospital between January 2016 and April 2019 with at least 1-year of follow-up. Patients were early revisions if they were revised within 2 years of primary THA (pTHA) or late revisions if revised after greater than 2 years. Patient demographics, surgical factors, and post-operative outcomes were compared between the groups. Post-hoc power analysis was performed (1-β=0.991). Results. 188 cases were identified, with 61 hips undergoing early revision and 127 undergoing late revision. There were no differences in demographics and comorbidities between the groups. Type of revision differed between the groups, with early revisions having a greater proportion of femoral revisions (54.1% vs.20.5%) and late revisions having a greater proportion of both component (10.2% vs.6.6%), acetabular (30.7% vs.26.2%), or head/liner (38.6% vs. 13.1%;p< 0.001) revisions. Indication for index revision differed between the groups, with early revisions having a greater proportion for dislocation/instability (21.3% vs. 10.2%) and peri-prosthetic fracture (42.6% vs.9.4%), and late revisions having a greater proportion for loosening/osteolysis (40.9% vs.24.6%), metal-on-metal complications (11.0% vs.0.0%), and liner wear (18.9% vs.0.0%;p< 0.001). Early revisions experienced longer length of stay (LOS; 5.18±4.43 vs.3.43±2.76 days;p=0.005) and more often underwent reoperation (8.2% vs 1.6%;p=0.037). Conclusions. Early aseptic revisions had worse outcomes with longer LOS and higher rates of reoperation. These differences may be attributable to the type and indication for revision. Arthroplasty surgeons should be aware of these differences when counseling patients after THA

Aims

Our primary aim was to assess reoperation-free survival at one year after the index injury in patients aged ≥ 75 years treated with internal fixation (IF) or arthroplasty for undisplaced femoral neck fractures (uFNFs). Secondary outcomes were reoperations and mortality analyzed separately.

Introduction. Short-stem hip arthroplasty is gaining popularity as a method of treating hip arthritis in biologically younger patients. The potential benefit of using a short-stem is preservation of bone in the proximal femur for a future revision. We have compared the early clinical and radiological results of a short-stem hip arthroplasty versus a conventional total hip arthroplasty (THA) using a standard length femoral prosthesis with particular focus on functional outcome. Methods. We evaluated a prospectively collected data on consecutive series of 249 patients, who underwent uncemented total hip arthroplasty at our institution. They were distributed into 2 groups: Group I, 125 patients received an uncemented short femoral stem (Mini Hip Arthroplasty (MHA), Corin, Cirencester) and Group II, 124 patients received a conventional uncemented femoral stem (Accolade, Stryker, Michigan) with mean follow up of 3.2 years (2–4). The characteristics of the two groups have been presented in Table I. Evaluation was based on plain radiographs performed at 6 months, 1 year and 2 years postoperatively, while their clinical status was assessed using the modified Harris hip score (mHHS) preoperatively and postoperatively at 6 weeks, 6 months, 1-year, 2-years and annually thereafter. Results. The outcome measures and complications in the two groups are presented in Table II. The mHHS was split into their two components (pain and function) to evaluate any differences between the groups. The postoperative results for pain were similar in both groups (p > 0.05), but the functional element of mHHS was significantly better (p < 0.05)* in Group I compared to Group II. This difference however did not reach the level of the minimum clinically important difference. All femoral stems showed radiographic evidence of bony ingrowth. No evidence of stem subsidence was found in any of the patients. One femoral implant was revised for infection in Group II. Conclusion. Our study suggests that the results of short-stem hip arthroplasty are comparable to conventional uncemented THA in the short-term. The functional outcome scores appear to be better in the short-stem group compared to the conventional group, but the difference is not clinically relevant. Short-stem hip arthroplasty can be an optimal choice for use in younger patients with good bone quality, who are expected to require revision in the future

Introduction. Hip arthroplasty is one of the most common procedures performed every year however complications do occur. Prior studies have examined the impact of insurance status on complications after TJA in small or focused cohorts. The purpose of our study was to utilize a large all-payer inpatient healthcare database to evaluate the effect of patient insurance status on complications following hip arthroplasty. Methods. Data was obtained from the Nationwide Inpatient Sample between 2004 and 2011. Analysis included patients undergoing hip arthroplasty procedures determined by ICD-9 procedure codes. Patient demographics and comorbidities were analyzed and stratified by insurance type. The primary outcome was medical complications, surgical complications and mortality during the same hospitalization. A secondary analysis was performed using a matched cohort comparing patients with Medicare vs private insurance using the coarsened exact matching algorithm. Pearson's chi-squared test and multivariate regression were performed. Results. Overall, 1,011,184 (64.8% Medicare, 29.3% private insurance, 3.7% Medicaid or uninsured, 2.0% Other) patients fulfilled criteria for inclusion into the study. Most were primary total hip arthroplasties (64.2%) and primary hip hemiarthroplasty (29.8%), with 6% revision hip arthroplasties. Multivariate regression analysis showed that patients with private insurance had fewer complications (OR 0.8, p=<0.001) and those with Medicaid or no insurance had more medical complications (OR 1.06, p=0.005) compared to Medicare patients. Similar trends were found for surgical complications and mortality. The matched cohort showed Medicare and private insurance patients had similar complication rates. The most common complication was postoperative anemia, occurring in 22.6% of Medicare patients and 21.1% of patients with private insurance (RR=1.06, p<0.001). Discussion and. Conclusion. This data reveals that patients with Medicare, Medicaid or no insurance have higher risk of medical complications, surgical complications and mortality following hip arthroplasty. Using a matched cohort to directly compare Medicare and private insurance patients, the risk of postoperative complications are similar and generally low with the notable exception of the most common complication, postoperative anemia, which occurs more frequently in patients with Medicare

Background and aim. Arthroplasty registries and consecutive series indicate significantly worse results of conventional metal-on-polyethylene total hip arthroplasty (THA) in patients younger than 50 years compared to older patients, with inferior clinical outcomes and 10-year survivorship ranging between 70 and 90%. At our institution, patients under 50 needing a THA receive either a metal-on-metal hip resurfacing (MoMHRA) or a ceramic-on-ceramic (CoC)THA. In order to evaluate the outcome of these options at minimum 10 years, we conducted a retrospective review of all MoMHRA and CoCTHA with more than 10 years follow-up implanted in patients under 50. Methods. From a single surgeon patients’ prospective database, we identified all consecutive THA performed before May 2005 in patients under 50. All patients are contacted by phone and asked to present for a clinical exam and patient reported outcome questionnaires, standard radiographs and metal ion measurements unless the hip arthroplasty has been revised. Complications and reasons for revision are noted. Kaplan-Meier survivorship is analysed for the whole cohort and sub-analysis is performed by type hip arthroplasty, gender, diagnosis and component size. Results. We identified 773 hip arthroplasties in 684 patients under 50 years performed by a single surgeon between 1997 and May 2005. There are 626 MoMHRA, all Birmingham Hip Resurfacings (BHR) in 561 patients (65 bilateral BHR), 135 CoCTHA in 111 patients (24 bilateral CoC) and 12 Metasul MoMTHA in 12 patients. In the BHR group, there are 392 males (70%) (42 bilateral) and 169 females (30%) (23 bilateral). Mean age at surgery was 40.8 years (median 42 years; range 16–50 years). In 33 cases, a BHR dysplasia cup was used (23 in females). Mean follow-up is 11.5 years (median 11 years; range 10–17 years). In the Metasul MoMTHA, there are 8 males and 4 females. Mean age at surgery was 40.4 years (range 20–50 years). All THA were non-cemented and head size was 28mm in all cases. Mean follow-up is 16.8 years (median 17.5 years; range 12–19 years). In the CoCTHA group, there are 71 males (64%) (17 bilateral) and 40 females (36%) (7 bilateral). Mean age at surgery was 38.2 years (median 39 years; range 16–50 years). In 21 cases, the CoCTHA was a revision of a former hip replacement: 15 THA revisions and 6 hip resurfacing revisions. Three types non-cemented acetabular components were used and 7 types femoral stems (5 non-cemented; 2 cemented). Ceramic heads and inlays were Biolox forte in 128 cases and Biolox delta in 7. Head size was 28mm in 125, 32mm in 7 and 36mm in 3. Mean follow-up is 14.9 years (median 15 years; range 10–18 years). Discussion. Patients under 50 needing a hip arthroplasty often present with more complex anatomic abnormalities or bone damage as in congenital dysplasia, avascular necrosis, traumatic osteoarthritis or rheumatic diseases. Besides, the worse results with conventional THA in young patients may be related to a higher activity level. We present the outcome and survivorship of MoMHRA and CoCTHA in patients under 50 at more than 10 years postop

The Canadian Cardiovascular Society (CCS) recommends performing daily troponin testing on postoperative days 0 through 3 for noncardiac surgical patients to decrease the mortality rate due to myocardial injury. Indications for testing include:

->65 yo

-45-64 yo with significant cardiovascular disease

-a Revised Cardiac Risk Index score (RCRI) > 1

Troponin elevation > 30 ng/L is termed “myocardial injury after noncardiac surgery” (MINS).

The study objective was to determine the prognostic relevance of applying CCS recommendations.

669 patients undergoing THA were included in the study. Based on the CCS recommendation there were 4 patient Groups depending on whether or not they met the MINS screening protocol criteria and whether or not it was applied:

-A - met & applied (n=181)

-B - met & not applied (n=248)

-C – not met & applied (n=10)

-D – not met & not applied (n=230)

307 (45.8%) males and 363 (54.2%) females with an average age of 67.8 years were included. Group A- 24% incidence (43 patients) of troponin rise & 5% incidence (9 patients) of cardiac complications. Group B- 0.4% incidence (1 patient) of cardiac complications.

Groups A + B – representing all patients who should have had the MINS screening protocol applied according to the CCS recommendations − 10 (2.3%) patients developed cardiac complication and one (0.2%) patient death

MINS screening protocol group (A & C) LOS was 4.0 days compared to 1.4 days for those not screened (p-value: <0.001).

Applying the CCS MINS screening protocol to elective THA patients added no benefit in predicting/preventing postoperative cardiac events but was associated with a significant increase in LOS. Following current CCS recommendations without more specifications and clinical evidence is unwarranted.

Aims. Short-stemmed femoral implants have been used for total hip arthroplasty (THA) in young and active patients to conserve bone, provide physiological loading, and reduce the incidence of thigh pain. Only short- to mid-term results have been presented and there have been concerns regarding component malalignment, incorrect sizing, and subsidence. This systematic review reports clinical and radiological outcomes, complications, revision rates, and implant survival in THA using short-stemmed femoral components. Materials and Methods. A literature review was performed using the EMBASE, Medline, and Cochrane databases. Strict inclusion and exclusion criteria were used to identify studies reporting clinical and radiological follow-up for short-stemmed hip arthroplasties. Results. A total of 28 studies were eligible for inclusion. This included 5322 hips in 4657 patients with a mean age of 59 years (13 to 94). The mean follow-up was 6.1 years (0.5 to 20). The mean Harris Hip Score improved from 46 (0 to 100) to 92 (39 to 100). The mean Oxford Hip Score improved from 25 (2 to 42.5) to 35 (12.4 to 48). The mean Western Ontario & McMaster Universities Osteoarthritis Index improved from 54 (2 to 95) to 22 (0 to 98). Components were aligned in a neutral coronal alignment in up to 90.9% of cases. A total of 15 studies reported component survivorship, which was 98.6% (92% to 100%) at a mean follow-up of 12.1 years. Conclusion. Short-stemmed femoral implants show similar improvement in clinical and radiological outcomes compared with conventional length implants. Only mid-term survivorship, however, is known. An abundance of short components have been developed and used commercially without staged clinical trials. Long-term survival is still unknown for many of these components. There remains tension between innovation and the moral duty to ensure that the introduction of new implants is controlled until safety and patient benefit are demonstrated. Implant innovation and subsequent use should be driven by proven clinical outcomes, rather than market and financial forces, and ethical practice must be ensured. Cite this article: Bone Joint J 2019;101-B:502–511

Introduction. Robotic-assisted hip arthroplasty helps acetabular preparation and implantation with the assistance of a robotic arm. A computed tomography (CT)-based navigation system is also helpful for acetabular preparation and implantation, however, there is no report to compare these methods. The purpose of this study is to compare the acetabular cup position between the assistance of the robotic arm and the CT-based navigation system in total hip arthroplasty for patients with osteoarthritis secondary to developmental dysplasia of the hip. Methods. We studied 31 hips of 28 patients who underwent the robotic-assisted hip arthroplasty (MAKO group) between August 2018 and March 2019 and 119 hips of 112 patients who received THA under CT-based navigation (CT-navi group) between September 2015 and November 2018. The preoperative diagnosis of all patients was osteoarthritis secondary to developmental dysplasia of the hip. They received the same cementless cup (Trident, Stryker). Robotic-assisted hip arthroplasty were performed by four surgeons while THA under CT-based navigation were performed by single senior surgeon. Target angle was 40 degree of radiological cup inclination (RI) and 15 degree of radiological cup anteversion (RA) in all patients. Propensity score matching was used to match the patients by gender, age, weight, height, BMI, and surgical approach in the two groups and 30 patients in each group were included in this study. Postoperative cup position was assessed using postoperative anterior-posterior pelvic radiograph by the Lewinnek's methods. The differences between target and postoperative cup position were investigated. Results. The acetabular cup position of all cases in both Mako and CT-navi group within Lewinnek's safe zone (RI: 40±10 degree; RA: 15±10 degree) in group were within this zone. Three was no significant difference of RI between Mako and CT-navi group (40.0 ± 2.1 degree vs 39.7± 3.6 degree). RA was 15.0 ± 1.2 degree and 17.0 ± 1.9 degree in MAKO group and in CT-navi group, respectively, with significant difference (p<0.001). The differences of RA between target and postoperative angle were smaller in MAKO group than CT-navi group (0.60± 1.05 degree vs 2.34± 1.40 degree, p<0.001). The difference or RI in MAKO group was smaller than in CT-navi, however, there was no significance between them (1.67± 1.27 degree vs 2.39± 2.68 degree, p=0.197). Conclusions. Both the assistance of the robotic arm and the CT-based navigation system were helpful to achieve the acetabular cup implantation, however, MAKO system achieved more accurate acetabular cup implantation than CT-based navigation system in total hip arthroplasty for the patients with OA secondary to DDH. Longer follow-up is necessary to investigate the clinical outcome

Proximal femoral replacements are commonly used in oncologic limb salvage procedures. Recently, these megaprostheses have been utilized in complex revision arthroplasties where proximal femoral bone is compromised. The purpose of this study is to evaluate the clinical and radiographic survivorship of proximal femoral replacements as a salvage treatment for bone loss after hip arthroplasty. We retrospectively reviewed the clinical and radiographic outcomes of 31 proximal femoral replacements of a single design between 2004 and 2013 at a single institution. The mean age at time of index surgery was 62 years, 58% were female, and mean BMI was 28.1 Kg/m. 2. The indications and complications associated with megaprosthesis implantation were collected. Average follow-up was 60 months (range 24–120 months). Kaplan-Meier survivorship assessed clinical and radiographic survivorship. Indication for revision, use of a constrained liner and construct length were assessed as risk factors for construct failure. The indications for proximal femoral replacement were periprosthetic infection (n=12, 38.7%), aseptic loosening (n=10, 32.3%), periprosthetic fracture (n=6, 19.3%), and non-union (n=3, 9.7%). A constrained liner was used in 22 hips (71%). The average length of bone resection was 148 cm (range 81–240 cm). There were nine revisions (29.2%): 3 for infection (9.7%) 2 for dislocation (6.5%), 2 for aseptic loosening (6.5%), and 2 for periprosthetic fracture (6.5%). Two of the 3 infections were in patients treated for infection. Overall survivorship was at 70.8%. There was no relation between the length of the bone resection, indication for revision and failure rate. Proximal femoral replacement in non-oncologic revision hip arthroplasty demonstrated a high failure rate at 2–10 year follow-up. Despite the high failure rate, the benefits of this salvage construct are that they allow full weight-bearing and allow rapid mobilization with minimal morbidity

Purpose. To analyze the effectiveness of a vancomycin impregnated calcium sulfate cement bead insertion after debridement (of) an acute-immediate stage infected hip arthroplasty. Materials and Methods. Between 2002 and 2008, 13 patients with documented acute-immediate stage infection of hip arthroplasty were reviewed and followed for at least two years postoperatively(average 4.3 years). The preoperative and postoperative clinical and radiologic findings and blood laboratory work were checked. All cases were performed through retention of the implant and massive debridement and saline irrigation. After that a vancomycin impregnated calcium sulfate cement beads was inserted. Results. After the first operation, the average interval for second operation was 27.7 days (17–37). At the second operation, the erythrocyte sediment rate and C-reactive protein were 150.97 mm/hr (34.6 ∼339.7 mm/hr) and 76.4 mg/L (41∼132 mg/L) respectively. Infectious organism were cultured and isolated. There were 5 cases of Methicillin resistant staphylococcus aureus (MRSA). In addition, results of an antibiotics sensitivity test were 8 cases of Vancomycin, and 5 cases of 3rd generation Cephalosporin. Radiologic results showed 10 cases with stable fixation on last follow-up (femoral stem) and 1 case of hip joint space narrowing, acetabular erosion. Conclusion. Vancomycin impregnated, calcium sulfate, cement bead insertion for an acute immediate infection of hip arthroplasty proved to be a useful method

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.

Polymethylmethacrylate (PMMA) bone cement is strong in compression, however it tends to fail under torsion. Sufficient pressurisation and subsequent interdigitation between cement and bone are critical for the mechanical interlock of cemented orthopaedic implants, and an irregular surface on the acetabular cup is necessary for reasonable fixation at the cup-cement interface. There is limited literature investigating discrepancies in the failure mechanisms of cemented all-polyethylene acetabular cups with and without cement spacers, under torsional loading.

In vitro experimental comparison of three groups of polyethylene acetabular prosthesis (PAP) cemented into prepared sawbone hemipelvises:

The constructs were tested to torstional failure on a custom designed setup, and statistical analysis done by a one-way ANOVA and Tukey-Welsh test.

Group 3 demonstrated superior torsional resistance with a statistically significant torque of 145Nm (SD±12Nm) at failure, compared to group 2 (109Nm, SD±7Nm) and group 1 (99Nm, SD±8Nm). Group 3 experienced failure predominantly at the bone-cement interface, in contrast, Groups 1 and 2 exhibited failure predominantly at the cup-cement interface. There was no significant difference between Group 1 and 2. Qualitative analysis of the failure mode indicates the efficient redistribution of stress throughout the cement mantle, consistent with the greater uniformity of cement.

PMMA spacers increase the resistance to torsional failure at the implant-cement interface. Acetabular components without spacers (Groups 1 and 2) failed at the implant-cement interface before the cement-bone interface, at a statistically significantly lower level of torque to failure. Although the PMMA spacers may reduce cement interdigitation at the cement-bone interface the torsional forces required to fail are likely supraphysiological.

Aims

This aim of this study was to assess the reliability and validity of the Unified Classification System (UCS) for postoperative periprosthetic femoral fractures (PFFs) around cemented polished taper-slip (PTS) stems.

Purpose. The purpose of this study was to assess the efficacy of newly designed topical administration of tranexamic acid (TXA) in reducing postoperative bleeding in total hip arthroplasty (THA) and bipolar hip hemiarthroplasty (BHA). Method. Consecutive series of 160 hip arthroplasty were enrolled for this study. Topical administration of TXA was done in group 1(40 hips of THA and 40 hips of BHA). We compared the amount of blood loss and rates of postoperative transfusion with group 2 (40 cases of THA and 40 cases of BHA) in which TXA solution was not applied. Results. The total amount of blood loss of THA group 1 and THA group 2 was 793±50 mL and 1086±73 mL respectively (p = 0.001). The transfusion rates of THA group 1 and THA group 2 was 27.5% and 50%, respectively (p= 0.039). The transfusion rates of BHA group 1 and BHA 2 group was 45% and 60%, respectively (p= 0.179). The amounts of blood loss through the drainage tube were 186±22 mL and 257±24 mL in THA group 1 and THA group 2, respectively, and 101±11 mL and 147±16 mL in BHA group 1 and BHA group 2, respectively, showing statistical significance. No complications such as infection, deep vein thrombosis, cardiovasular disease were observed during the hospital stay and last follow-up. Conclusion. Topical administration of TXA is an effective and safe method to reduce postoperative bleeding and transfusion rates in hip arthroplasty

Objectives. T-cells are considered to play an important role in the inflammatory response causing arthroplasty failure. The study objectives were to investigate the composition and distribution of CD4+ T-cell phenotypes in the peripheral blood (PB) and synovial fluid (SF) of patients undergoing revision surgery for failed metal-on-metal (MoM) and metal-on-polyethylene (MoP) hip arthroplasties, and in patients awaiting total hip arthroplasty. Methods. In this prospective case-control study, PB and SF were obtained from 22 patients (23 hips) undergoing revision of MoM (n = 14) and MoP (n = 9) hip arthroplasties, with eight controls provided from primary hip osteoarthritis cases awaiting arthroplasty. Lymphocyte subtypes in samples were analysed using flow cytometry. Results. The percentages of CD4+ T-cell subtypes in PB were not different between groups. The CD4+ T-cells in the SF of MoM hips showed a completely different distribution of phenotypes compared with that found in the PB in the same patients, including significantly decreased CD4+ T-central memory cells (p < 0.05) and increased T-effector memory cells (p < 0.0001) in the SF. Inducible co-stimulator (ICOS) was the only co-stimulatory molecule with different expression on CD4+ CD28+ cells between groups. In PB, ICOS expression was increased in MoM (p < 0.001) and MoP (p < 0.05) cases compared with the controls. In SF, ICOS expression was increased in MoM hips compared with MoP hips (p < 0.05). Conclusions. Increased expression of ICOS on CD4+ T-cells in PB and SF of patients with failed arthroplasties suggests that these cells are activated and involved in generating immune responses. Variations in ICOS expression between MoM and MoP hips may indicate different modes of arthroplasty failure. Cite this article: Professor P. A. Revell. Increased expression of inducible co-stimulator on CD4+ T-cells in the peripheral blood and synovial fluid of patients with failed hip arthroplasties. Bone Joint Res 2016;5:52–60. doi: 10.1302/2046-3758.52.2000574

INTRODUCTION. The Woodpecker pneumatic broaching system facilitates femoral preparation to achieve optimal primary fixation of the stem in direct anterior hip replacement using a standard operating table. The high-frequency axial impulses of the device reduce excess bone tension, intraoperative femoral fractures and overall operating time. The Woodpecker device provides uniformity and enhanced control while broaching, optimizing cortical contact between the femur and implant and thereby maximizing prosthetic axial stability and longevity. This study aims to describe a single surgeon's experience using the Woodpecker pneumatic broaching system in 649 cases of direct anterior approach (DAA) total hip arthroplasties to determine the device's safety and efficacy. METHODOLOGY. All consecutive patients undergoing elective anterior bikini total hip arthroplasties (THA) performed by a single surgeon between July 2013 and June 2018 were included. Patients undergoing a THA with the use of the Woodpecker device through a different surgical approach, revision THA or arthroplasties for a fractured neck of femur were excluded (n=219). The pneumatic device was used for broaching the femoral canal in all cases. Pre-operative and post-operative Harris Hip Scores (HHS) and post-operative radiographs were analyzed to identify femoral fractures and femoral component positioning at 6 weeks, 6 months and 12 months post-operative. Any intra-operative or post-operative surgical complications and component survivorship until most recent follow up were recorded in the clinical notes. RESULTS. A total of 649 patients (L THA=317, R THA=328 and bilateral=2) with a mean age of 69 (range 46–91yrs) and mean BMI of 28.3 (range = 18.4–44.0) underwent a DAA THA using a Woodpecker device were included in the study. Of these patients, 521 (80%) underwent uncemented and 128 (20%) underwent cemented femoral components. The time taken to broach the femur using Woodpecker broaching this system averaged 2.8 minutes (1.4 to 7.5 minutes) in both cemented and uncemented cases. In 91% of cases the templated broach size was achieved with the remaining 9% within +/− 1 size of the planned template. Radiographic analysis revealed 67.3% of the stems placed in 0–1.82 degrees of varus and 32.7% placed in 0–1.4 degrees of valgus. Average HHS were 24.4 pre-operatively, with drastic improvements shown at 6 weeks (80.95), 6 months (91.91) and 12 months (94.18) after surgery. Intraoperative femoral fractures occurred in three patients (0.4%) during trial reduction, a further three patients had periprosthetic post-operative fractures (0.4%) from falls, two patients had stem subsidence (0.3%) and a further two patients had wound infections (0.3%). At the most recent follow up, the survivorship of the acetabular component was 99.7% and the femoral component was 99.1%, with mean follow up of 2.9 years (0.5 to 5 years). No intraoperative or post-operative complications could be directly attributed to the Woodpecker broaching system. CONCLUSION. The pneumatic Woodpecker device is a safe and effective alternative tool in minimally invasive direct anterior hip replacement surgery for femoral broaching performed on a standard operating table. The skill and experience of the surgeon must be taken into consideration when utilizing new surgical devices

The development of an algorithm that provides accurate individualised estimates of revision risk could help patients make informed surgical treatment choices. This requires building a survival model based on fixed and modifiable risk factors that predict outcome at the individual level. Here we compare different survival models for predicting prosthesis survivorship after hip replacement for osteoarthritis using data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. In this comparative study we implemented parametric and flexible parametric (FP) methods and random survival forests (RSF). The overall performance of the parametric models was compared using Akaike information criterion (AIC). The preferred parametric model and the RSF algorithm were further compared in terms of the Brier score, concordance index (C index) and calibration. The dataset contains 327 238 hip replacements for osteoarthritis carried out in England and Wales between 2003 and 2015. The AIC value for the FP model was the lowest. The averages of survival probability estimates were in good agreement with the observed values for the FP model and the RSF algorithm. The integrated Brier score of the FP model and the RSF approach over 10 years were similar: 0.011 (95% confidence interval: 0.011–0.011). The C index of the FP model at 10 years was 59.4% (95% confidence interval: 59.4%–59.4%). This was 56.2% (56.1%–56.3%) for the RSF method. The FP model outperformed other commonly used survival models across chosen validation criteria. However, it does not provide high discriminatory power at the individual level. Models with more comprehensive risk adjustment may provide additional insights for individual risk

Aims

Proximal femoral endoprosthetic replacements (PFEPRs) are the most common reconstruction option for osseous defects following primary and metastatic tumour resection. This study aimed to compare the rate of implant failure between PFEPRs with monopolar and bipolar hemiarthroplasties and acetabular arthroplasties, and determine the optimum articulation for revision PFEPRs.

Aim

The duration of systemic antibiotic therapy following first-stage surgery is contentious. Our Institution's philosophy is to perform an aggressive debridement, use high concentration targeted antibiotics through cement beads and systemic prophylactic antibiotics alone. In the presence of significant soft tissue infection or microbiological diagnostic uncertainty; systemic antibiotics may be prescribed for 5 days whilst awaiting tissue culture results. The aim of this study was to assess the success of our philosophy in the management of PJI of the hip using our two-stage protocol.

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.

The variables involved in a robotic THA can exceed 52: many parameters as pelvic orientation with CT scan, templating, offset, and leg-length, acetabular reaming, femoral osteotomy, mapping the anatomy; predefining safe zones, robotic execution, femoral head size, thickness of PE etc. with several variables for each parameter, with a total number of variables exceeding 52. This familiar number is the number of cards in a standard deck. The number of possible combinations (factorial 52! = 10^67) to shuffle the cards (and may be to perform a THA) is greater than the number of atoms on earth! Thinking that artificial intelligence and robotics can solve these problems, some surgeons and implant manufacturers have turned to artificial intelligence and robotics.

We asked two questions:1) can robot with artificial intelligence really process 52 variables that represent 10^67 combinations? 2) the safety of the technology was ascertained by interrogating Food and Drug Administration (FDA) database about software-related recalls in computer-assisted and robotic arthroplasty [1], between 2017 and 2022.

1)

The best computers can only calculate around 100 thousand billion combinations (10^14), and with difficulty: it takes more than 100 days to arrive at this number of digits (10^14) after the decimal point for the number π (pi). We can, therefore, expect the robot to be imperfect.

Hip surgeon is as intelligent as a robot and almost twice as safe.

The objective of this study was to evaluate the short term clinical and radiological results of a new short stem hip implant. In 29 consecutive patients suffering from osteoarthritis with 33 affected hip joints, the clinical and radiological results of 33 cementless hip arthroplasties using a cementless implanted short stem prosthesis type Aida and a cementless cup type Ecofit were evaluated prospectively between October 2009 and June 2015 in two hospitals. The median age of patients at time of surgery was 55 years (range, 30–71 years), 23 male and 10 female patients were included in the study. The median clinical follow up was 24 months (range, 1.5–51 months), and the median radiological follow up was 12 months (range, 1–51 months). Two patients were lost to follow up and two patients had only one immediate postoperative x- ray. The Harris Hip Score improved from a median preoperative value of 53 to a median postoperative value of 93 at follow up. Radiological analysis showed that 19 stems (58%) showed stable bony ingrowth, five cases (15%) showed stable fibrous ingrowth. Four cases need further follow up for proper evaluation of stem fixation. The short term survival of this new short stem is very promising, and achieving the goals of standard hip arthroplasty

Two major complications of hip replacement are loosening and infection. Reliable differentiation between these pathological processes is difficult since both may be accompanied by similar symptoms. Our aim was to assess the diagnostic ability of triple-phase bone scanning (TPBS) and positron-emission tomography (PET) to detect and differentiate these complications in patients with a hip arthroplasty. Both TPBS and PET were performed in 63 patients (92 prostheses). The radiotracer for PET imaging was . 18. F-fluorodeoxyglucose (FDG). Image interpretation was performed according to qualitative and quantitative criteria although the final diagnosis was based upon either surgical findings or clinical follow-up. The sensitivity, specificity and accuracy of PET was 0.94, 0.95 and 0.95 respectively, compared with 0.68, 0.76 and 0.74 for TPBS. We found that an image interpretation based exclusively upon quantitative criteria was inappropriate because of its low selectivity. The histological examination indicated that increased periprosthetic uptake of FDG in patients with aseptic loosening was caused by wear-induced polyethylene particles and the subsequent growth of aggressive granulomatous tissue

Background. Hip resurfacing arthroplasty (HRA) and total hip arthroplasty (THA) are treatments of end-stage hip disease. Gait analysis studies comparing HRA and THA have demonstrated HRA results in a more normal gait than THA. The reasons may include the larger, more anatomic head diameter, the preservation of the femoral neck with restoration of the anatomical hip centre position and normal proprioception. This study investigated (1)whether femoral head size diameter affects gait; (2)whether gait still differs between THA and HRA patients even with comparable head diameters. Methods. We analysed the gait of 33 controls and 50 patients with unilateral hip replacement. Follow-up ranged from 9–68 months. In 27 hips a small femoral head size was used (≤ 36mm); in 23 hips a large head size (>36mm). The small size group consisted of 11 long femoral stem THA and 16 short-stem THA; the large group of 5 long-stem, 8 short-stem THA and 10 HRA patients. There were 14 females/19 males in the control group; 22 females/5 males in the small size group; 13 females/10 males in the large size group. Results. (1) We found a significant difference in step-length between small head sizes and controls (p<0.01) at speeds ranging from 4.0 to 5.5 km/h but no difference between the larger head size and the controls. There was no significant difference in maximum speed, weight acceptance, push-off, mid-stance, impulse and cadence between the groups. (2)Analysis between THA and HRA in the large head size group revealed a significant difference in maximum speed (p=0.021) between long-stem THA (6.338 km/h± 1.542) and HRA (7.756km/h± 0.7604) patients. At 5.5 km/h there was a significantly better weight acceptance (p=0.009) and mid-stance (p=0.041) of HRA compared to short-stems. Impulse was significantly higher for HRA compared to long-stem THA (p<0.05) at all speeds ranging 4 to 5.5 km/h. (3)Males (7.1972 km/h ± .9700) had significantly higher maximum speeds compared to females (6.6524km/h± 1.019) (p=0.017) and lower gait impulse (p<0.01) at speeds ranging from 4 to 5.5km/h. (4)There was no significant difference in Oxford Hip Score (OHS) and EQ-5D of patients in the small compared to large head size group. Conclusions. Gait analysis demonstrated a significant difference in step length between THA patients with head size ≤ 36mm and normal controls. There was no difference in step length between normal controls and THA patients with larger head sizes. Compared to larger head size THA, HRA still revealed higher maximum speeds and better weight acceptance. Males had significantly higher maximum speeds compared to females (controls and hip replacement patients). We could not demonstrate a correlation between better gait and Oxford scores or EQ-5D scores but these are known to have a ceiling effect. In a former study, better gait parameters such as longer step length and higher maximum speed have been associated with higher patient satisfaction

Introduction There are no reports on the epidemiology of revision hip arthroplasty in Australia. The aim of this study was to characterise the epidemiology of revision hip arthroplasty in relation to primary hip replacements in Australia. Methods This study covered the seven year period 1993/1994 to 1999/2000. Data on all primary hip replacements and revisions done were obtained from the Australian Institute of Health and Welfare using the ICD-9 (81.53) and ICD-10 (Block No. 1492) cartegorisation. The data was stratified by age (five year age groups), sex, year and state or territory. Log linear modelling was used to examine the rate of revision procedures out of the total number of procedures (primary and revision). The effects of gender, age and year were examined in a series of hierarchical log-rate models (Poisson Loglinear Regression). Results For the period of the study there were 18,027 revision cases and 122,595 cases of primary hip replacement, representing a revision rate of 14%. The rate of increase of primary hip replacements was significantly higher than the rate of increase of revisions (t= −12.1, p< 0.0005). The number of primary hip replacements performed nationally increased by 810 (95% confidence intervals 658,964) a year. The number of revisions increased by only 62 (95% confidence intervals 21,104) a year. The proportion of revisions decreased by 0.3% per year as determined by regression analysis. The hierarchical log-rate models indicate significant interactions between age and gender and beween age and year. Conclusions The number of primary and revision hip replacements has been increasing with time. The rate of increase of revision hip replacements has been lower. The proportion of hip replacements that are revisions has been gradually dropping, probably due to a greater increase in the number of primary hip replacements

Juvenile idiopathic arthritis (JIA) is a chronic disease of childhood; it causes joint damage which may require surgical intervention, often in the young adult. The aim of this study was to describe the long-term outcome and survival of hip replacement in a group of adult patients with JIA and to determine predictors of survival for the prosthesis. In this retrospective comparative study patients were identified from the database of a regional specialist adult JIA clinic. This documented a series of 47 hip replacements performed in 25 adult patients with JIA. Surgery was performed at a mean age of 27 years (11 to 47), with a mean follow-up of 19 years (2 to 36). The mean Western Ontario and McMaster Universities osteoarthritis index questionnaire (WOMAC) score at the last follow-up was 53 (19 to 96) and the mean Health Assessment Questionnaire score was 2.25 (0 to 3). The mean pain component of the WOMAC score (60 (20 to 100)) was significantly higher than the mean functional component score (46 (0 to 97)) (p = 0.02). Kaplan-Meier survival analysis revealed a survival probability of 46.6% (95% confidence interval 37.5 to 55.7) at 19 years, with a trend towards enhanced survival with the use of a cemented acetabular component and a cementless femoral component. This was not, however, statistically significant (acetabular component, p = 0.76, femoral component, p = 0.45). Cox’s proportional hazards regression analysis showed an implant survival rate of 54.9% at 19 years at the mean of covariates. Survival of the prosthesis was significantly poorer (p = 0.001) in patients who had been taking long-term corticosteroids and significantly better (p = 0.02) in patients on methotrexate

Introduction: Deep infection continues to be the second most important early complication in hip arthroplasty. It is usual to apply standard prophylaxis to all patients, but it is not usual to use special measures in those of them who present a higher risk. Moreover, sometimes these patients are even not identified. Purpose: To analyse statistically significant risk factors for deep infection in patients with a hip arthroplasty. Patients and Methods:. Design: Case-control study. Observational and retrospective comparison of incidence or prevalence of all risk factors described in the literature. These factors have been classified according to the period of risk in: epidemiologic; pre, intra and postoperative; and distant infections. Case series: 47 consecutive patients with a deeply infected hip arthroplasty operated in the same Department of a University General Hospital. Control series: 200 randomly selected patients, operated in the same hospital and period of time, with no deep infection in their hip arthroplasty along follow-up. Pearson was used for comparison of qualitative variables and ANOVA for quantitative ones. Results: The following risk factors were significantly more frequent (p< 0.05) in the patients with an infected hip arthroplasty:. Epidemiologic characteristics: female gender, post-traumatic osteoarthritis (17% vs 3%). On the contrary, primary osteoarthritis is a “protective” factor. Preoperative conditions: previous surgery in the same hip (60% vs 6%), obesity (BMI> 30) (9% vs 1%), chronic therapy with glucocorticoids (13% vs 0%), immunosuppressive treatments, chronic liver diseases (20% vs 2%), alcohol addiction (13% vs 0%) and intravenous drug abuse. Patients in this case-control did not present a significant difference in the prevalence of diabetes (a recognised risk factor for spine and knee surgery) or rheumatoid arthritis. Intraoperative facts: a prolonged surgical time is the only significant risk factor (133 min vs 98 min), but differences were not found in the amount of bleeding, need for transfusion or intraoperative fractures. Postoperative events: secretion of the wound longer than 10 days (46% vs 8%), palpable deep haematoma (27% vs 1%), dislocation of the prosthesis (40% vs 6%), and need for new surgery in the hip (21% vs 1%). Distant infections (risk for haematogenous seeding): deep cutaneous (30% vs 8%), upper and lower urinary tract (36% vs 2%), pneumonias and bronchopneumonias (23% vs 5%), and diverse abdominal focus (14% vs 3%). On the contrary, significant differences were not found in the prevalence of severe oral or dental infections. Conclusion: To identify significative risk factors for deep infection in hip arthroplasty is important:. to control and minimize these risk factors when present. when this is not possible not possible, to implement additional prophylactic measures

The principle function of the “short external rotator” muscle group is primarily as an abductor and extensor of the flexed hip and is better referred to as the “Quadriceps Coxa” (QC). The QC has a profound influenced on weight bearing rising and propulsive motions. The SPAIRE technique preserves Obturator Internus (OI) and Piriformis (P) resulting in improved stability of the hip and potentially improved recovery and function in patients undergoing hip arthroplasty. Short term outcomes of the first 42 consecutive SPAIRE cases are compared with 86 consecutive cases using the traditional posterior approach that immediately preceded introduction of the technique. The purpose was to document the learning curve and confirm the safety of introducing SPAIRE into routine clinical practice. The two groups were comparable and there was no statistically significant difference in length of stay, blood loss, intra-or post-operative complications nor radiological measurements relating to the femoral or acetabular components. Statistically significant differences were found for component usage (more uncemented acetabula for SPAIRE), length of operation (8 mins longer with SPAIRE); patient satisfaction was higher at 6 weeks and measured leg length discrepancy less in the SPAIRE group. SPAIRE has been used routinely for all routine arthroplasties for over two years. RCTs are ongoing to document the effect of SPAIRE on recovery, long term function and activity level. If the potential benefits are confirmed SPAIRE may become the default technique for hip arthroplasty operations through a posterior approach for elective and hip fracture cases

Introduction: Infected hip arthroplasties have usually been managed with either one or two stage revisions using antibiotic impregnated cement to fix the components. The use of cementless fixation has been less widely reported. The results on the femoral side have been less encouraging. Aim: To present the short to medium term results of cementless revision for infected hip arthroplasty. Methods: Ten patients who had undergone cementless revisions for infected hip arthroplasties have been followed prospectively. There were eight males and two females with an average age of 67 years. Nine of the 10 patients were treated with two-stage revisions with one female undergoing a one-stage revision for medical reasons. The diagnosis of sepsis was made on the basis of bacterial cultures and positive histology from all patients. Removal of the prosthesis was followed by the administration of intravenous antibiotics for six weeks and, in some, cases oral antibiotics for several months. The reconstructions were undertaken following the Girdlestone’s arthroplasties with a range from eight weeks to three years, (with the exception of the one stage exchange). Results: The patients were examined from 18 to 64 months after the surgery with none lost to follow-up. All prostheses remained in situ with improvements in the Charnley and Oxford hip scores. There had been no recurrence of infection and no clinical or radiological evidence of loosening. Discussion: Debate still exists about the merits of one-stage versus two-stage reconstruction for an infected hip arthroplasty. The use of antibiotic-impregnated cement has been recommended, especially for the femoral component. This series demonstrated that cementless reconstruction for infected hip arthroplasty was successful in providing an infection free, stable hip in the short to medium term

Background. Hip resurfacing arthroplasty (HRA) and total hip arthroplasty (THA) are treatments of end-stage hip disease. Gait analysis studies comparing HRA and THA have demonstrated that HRA results in a more normal gait than THA. The reasons may include the larger, more anatomic head diameter or the preservation of the neck of the femur with restoration of the anatomical position of the hip centre and normal proprioception. This study investigated (1) whether femoral head size diameter affects gait; (2) whether gait still differs between THA and HRA patients even with comparable head diameters. Methods. We retrospectively analysed the gait of 33 controls and 50 patients with a unilateral hip replacement, operated by the same surgeon. Follow-up ranged from 9–68 months. In 27 hips a small femoral head size was used (≤ 36mm); in 23 hips a large head size (>36mm). The small size group consisted of 11 long femoral stem THA and 16 short-stem THA and the large group of 5 long-stem THA, 8 short-stem THA and 10 HRA patients. There were 14 females/19 males in the control group; 22 females/5 males in the small size group; 13 females/10 males in the large size group. Results. (1) We found a significant difference in the step-length between the small head size group and the controls (p<0.01) at speeds ranging from 4.0 to 5.5 km/h but no difference between the larger head size and the controls. There was no significant difference in maximum speed, weight acceptance, push-off, mid-stance, impulse and cadence between the groups. (2) Analysis between THA and HRA in the large head size group revealed that there was a significant difference in the maximum speed (p=0.021) between the long-stem THA (6.338 km/h± 1.542) and HRA (7.756km/h± 0.7604) patients. At 5.5 km/h there was a significantly better weight acceptance (p=0.009) and mid-stance (p=0.041) of the HRA compared to short-stems. Impulse was significantly higher for HRA compared to long-stem THA (p<0.05) at all speeds ranging 4 to 5.5 km/h. (3) Males (7.1972 km/h ± .9700) had significantly higher maximum speeds compared to females (6.6524km/h± 1.019) (p=0.017) and lower gait impulse (p<0.01) at speeds ranging from 4 to 5.5km/h. (4) There was no significant difference in the Oxford Hip Score (OHS) and EQ-5D of patients in the small compared to the large head size group. Conclusions. Gait analysis demonstrated a significant difference in step length between THA patients with head size ≤ 36mm and normal controls. There was no difference in step length between normal controls and THA patients with larger head sizes. Compared to larger head size THA, the HRA still revealed higher maximum speeds and better weight acceptance. Males had significantly higher maximum speeds compared to females (controls and hip replacement patients). We could not demonstrate a correlation between better gait and Oxford scores or EQ-5D scores but these scores are known to have a ceiling effect. In a former study, better gait parameters such as longer step length and higher maximum speed have been associated with higher patient satisfaction

BACKGROUND. Hip arthroplasty is an ultimate treatment for individuals with severe hip osteoarthritis. There are several available approaches when performing this type of surgery, however there is a growing interest in using the least invasive procedures. These less invasive procedures aid in healthy bone preservation which may be particularly important for younger populations undergoing hip arthoplasy (Rajakulendran & Field, 2012). Accurate and reliable measurement techniques are needed to better study and monitor the outcome of different implantation techniques during the postop recovery. OBJECTIVES. To develop a better understanding of spatiotemporal aspects of gait pre- and post- hip arthroplasty through the anterior approach. METHODS. Six subjects treated with an anterior approach hip-arthroplasty were instructed to walk over a 30 foot walkway while wearing a lumbar gait sensor that is equipped with an accelerometer and gyroscope used to track changes in body position and hip angles. Subjects were tested before surgery, 3 and 6 weeks post-surgery, and 3 and 6 months post-surgery. The subjects were compared to healthy, age-matched controls. RESULTS. The use of this device enabled the measurement of consistent gait temporal characteristics throughout the different time points. It was found that spatiotemporal parameters improved as time progressed post-surgery. Furthermore, it is noted that the most substantial improvements were observed after the six week mark with a possible plateauing observed after the three month mark. The following figures illustrate the changes over time experienced by a subject. Their data is also compared to that of a healthy control. Figure 1 summarizes the 6-month follow up results of a female subject with anterior approach THA. CONCLUSIONS. The greatest improvements in performance were observed as early as 6 weeks post-surgery in some of the subjects. The data also suggests that improvements may plateau after 3 months post-surgery. These biomechanical findings may help with post-surgical physical activity and therapeutic recommendations as well as providing clinicians with a better prognosis time frame for the anterior approach hip arthroplasty

Introduction: Hip arthroplasty represents a large consumer of resources in orthopaedic surgery. Although the need for follow up is universally accepted, there is much debate on the duration and frequency of outpatient visits. To date there is no evidence regarding the cost effectiveness of follow up. There are no NICE guidelines for hip arthroplasty follow up. 90% of hip arthroplasty failures do so after 5 years. Joint replacement review is performed by a variety of personnel including orthopaedic surgeons, surgical care practitioners (SCPs) and extended scope practitioners (ESPs). Patients are reviewed in an outpatient clinic or by questionnaire. Methods: A questionnaire was sent out to orthopaedic surgeons working in the Sandwell and West Birmingham Hospitals Trust enquiring about their practice for following up patients who have had hip replacements. Information regarding the length of follow up, frequency of visits and the use of check radiographs was recorded. Results: The mean length of follow up was 28.8 months. (12–60 months). The mean number of visits in the first year was 3.9. (3–4). The mean number of total visits was 6. (4–9). The mean number of check radiographs performed in the first year was 2. Mean total number of check radiographs performed was 4. The mean cost for each patient is 590 pounds. (224–896 pounds). Discussion: There is considerable variation in hip arthroplasty follow up with ensuing cost implications. Guidance is required for the appropriate review, which will allow early detection of complications in an efficient and cost effective manner. In our trust a protocol has been suggested for the follow up of hip arthroplasty by ESPs and SCPs

Introduction: There are descriptions in the medical literature of asymptomatic bacteriurias in 30% of post-menopausal women. Purpose: To analyze the prevalence of asymptomatic bacteriuria and the risk of blood-route dissemination in patients undergoing elective hip arthroplasty. Patients and Methods: All asymptomatic patients undergoing surgical hip arthroplasty between January 15, 2007 and March 30, 2007 were included. There was a total of 45 patients of 65.9 +/−12.9 (range: 33–85) years of age, out of which 23 (51.1%) were male. A urine test was administered on admission (12 hours before surgery). Normal analysis: density< 1.006/> 1.030; pH< 4.6/> 7.0; leucocytes and/or positive nitrites; sediment with bacteriuria, piouria and/or > 5 leucocytes/field. If the urine analysis was abnormal, a preoperative quantitative uroculture was carried out. If < 10000 CFUs/ml, no UTI (urinary tract infection); if > 10000 but < 100000, a new urine culture was performed; if > 100000 CFUs, diagnosis of UTI, specific oral antibiotics were administered for 7 days postoperatively. None of the patients underwent urethra catheterization. All received cefazoline 1g i.v/8 hours for 48 hours postoperatively. Results: Loss to follow-up: 0 patients. Normal analysis: 12/45(26.7%) patients of 73.8+/−8.5 (55–85) years of age, 12 females (100.0%). In 1 of these 12 patients (8.3%) (1/45 or 2.2% of the total series) the urine culture was positive for Pseudomona aeruginosa. Up to the current time none of these 45 patients has developed signs of infection in their arthroplasty. Conclusions:. (1) Women undergoing elective hip arthroplasty frequently have abnormal preoperative urine analysis. (2) Asymptomatic urinary infection is only detected in a small percentage of patients that undergo programmed hip arthroplasty. (3) No hip prosthesis infection has been seen during follow-up up to the current time

Objectives. Previous studies have suggested that metal-on-metal (MoM) Pinnacle (DePuy Synthes, Warsaw, Indiana) hip arthroplasties implanted after 2006 exhibit higher failure rates. This was attributed to the production of implants with reduced diametrical clearances between their bearing surfaces, which, it was speculated, were outside manufacturing tolerances. This study aimed to better understand the performance of Pinnacle Systems manufactured before and after this event. Methods. A total of 92 retrieved MoM Pinnacle hips were analyzed, of which 45 were implanted before 2007, and 47 from 2007 onwards. The ‘pre-2007’ group contained 45 implants retrieved from 21 male and 24 female patients, with a median age of 61.3 years (interquartile range (IQR) 57.1 to 65.5); the ‘2007 onwards’ group contained 47 implants retrieved from 19 male and 28 female patients, with a median age of 61.8 years (IQR 58.5 to 67.8). The volume of material lost from their bearing and taper surfaces was measured using coordinate and roundness measuring machines. These outcomes were then compared statistically using linear regression models, adjusting for potentially confounding factors. Results. There was no significant difference between the taper and bearing wear rates of the ‘pre-2007’ and ‘2007 onwards’ groups (p = 0.67 and p = 0.39, respectively). Pinnacles implanted from 2007 onwards were revised after a mean time of 50 months, which was significantly earlier than the ‘pre-2007’ hips (96 months) (p < 0.001). A reduction in the time to revision was present year on year from 2003 to 2011. Conclusion. We found no difference in the wear rate of these implants based on the year of implantation. The ‘pre-2007’ hips had a two-fold greater time to revision than those implanted after 2007; this may be due to the increased surveillance of MoM hips following UK regulatory advice and several high-profile failures. Interestingly, we observed a decreasing trend in the mean time to revision every year from 2003 onwards. Cite this article: S. Bergiers, H. S. Hothi, J. Henckel, A. Eskelinen, J. Skinner, A. Hart. Wear performance of retrieved metal-on-metal Pinnacle hip arthroplasties implanted before and after 2007. Bone Joint Res 2018;7:595–600. DOI: 10.1302/2046-3758.711.BJR-2018-0143.R1

Aims

Large-diameter metal-on-metal (MoM) total hip arthroplasty (THA) has demonstrated unexpected high failure rates and pseudotumour formation. The purpose of this prospective cohort study is to report ten-year results in order to establish revision rate, prevalence of pseudotumour formation, and relation with whole blood cobalt levels.

Surgical treatment of Hip PJI by resection of the infected implants and tissue and placement of a “spacer” which elutes antibiotic via antibiotic loaded cement is an accepted treatment option. There is some controversy over whether this “spacer” should be articulating or static. Proponents of the articulating option argue that there is improved function and maintenance of the soft tissue envelop. Critics have suggested that additional biomaterials may compromise eradication of infection. This study compares our results of the 2 treatment options.

A review of our institutional PJI database between 2016 and 2021 identified 87 patients who were treated with resection arthroplasty for unilateral total hip PJI. The cohort was analyzed for demographics and type for surgery, as well as medical comorbidities, survivorship, and treatment success.

44 patients were female, the mean age of all patients was 62. 44 patients were treated with Articulating apacers, and 43 patients treated with static spacers. There was no significant difference between ASA or Elixhauser score, and no significant difference between mortality or treatment failure.

This study did not show any difference between the patients who receive static spacers, from those who received articulating spacers, and deomstrated similar treatment success rates. From this data there does not appear to be any difference in success rates between those patients that were treated with static spacers and those that were treated with articulating spacers.

Background

Data regarding the diagnostic value of ultrasound (US)-determined fluid film and joint aspiration prior to revision total hip arthroplasty (THA) for suspected periprosthetic joint infections (PJIs) is limited. This study aimed to analyse (1) the value of US-determined fluid film, (2) characterisation of the pre- and intraoperative microbiological spectrum and resistance patterns and (3) the concordance between preoperative synovial fluid and intraoperative culture results.

The in-cement technique for revision hip arthroplasty involves retaining the original cement-bone interface. This has been proven to be a biomechanically stronger method than recementing after complete removal of the original cement mantle. This study reviewed a series of 54 consecutive revision hip arthroplasty procedures, using the in-cement technique, between November 1999 and November 2003. Clinical and radiological follow-up included functional assessment. There were 54 procedures performed in 51 patients, whose mean age at surgery was 70.3 years (45 to 85). A total of 42 were available at a mean follow-up of 29.2 months (6 to 51). There was no radiological evidence of loosening. Functional assessments were available for 40 patients who had a mean Harris hip score of 85.2 (51.9 to 98.5), a mean Oxford hip score of 19.6 (12 to 41), a mean UCLA activity profile score of 5.9 (3 to 8) and a mean SF-36 score of 78.0 (31.6 to 100). The in-cement technique provides consistent, high functional outcomes and should be considered in appropriately selected cases

Aims

Highly polished stems with force-closed design have shown satisfactory clinical results despite being related to relatively high early migration. It has been suggested that the minimal thickness of cement mantles surrounding the femoral stem should be 2 mm to 4 mm to avoid aseptic loosening. The line-to-line cementing technique of the femoral stem, designed to achieve stem press-fit, challenges this opinion. We compared the migration of a highly polished stem with force-closed design by standard and line-to-line cementing to investigate whether differences in early migration of the stems occur in a clinical study.

The SPAIRE technique (Spare Piriformis And Internus, Repair Externus) involves a muscle sparing mini-posterior approach to the hip. Evidence will be prevented that the principle function of the “short external rotator” muscle group is primarily as an abductor and extensor of the flexed hip and has a profound influenced on weight bearing rising and propulsive motions; also that details of the insertions of the piriformis tendon and conjoint insertion of obturator internus and the gemelli (the Quadriceps Coxa) have previously been poorly appreciated. We have developed a surgical technique (SPAIRE) during which the only tendon released, and subsequently repaired, is obturator externus. The author has carried out the SPAIRE technique for all routine hip arthroplasties for the last 18 months. This cohort has been compared with a matched control group for a comprehensive array of outcome measures. Results show no disadvantage of using the technique. On-table stability is so impressive that when the SPAIRE technique has been used no postoperative restrictions whatsoever are placed on the patient who is immediately encouraged to exercise the hip through a full excursion of movement. Fewer tendons are damaged using the SPAIRE technique than any other approach to the hip including Direct Anterior and Direct Superior approaches. Randomised prospective studies are on-going using objective measurements of Gait and muscle power as well as functional and patient reported outcomes to prove benefit of the SPAIRE technique. For hemiarthroplasty cases a separate RCT is being undertaken comparing the SPAIRE technique with a direct lateral approach. It is believed that this technique may become the default technique for hemi- and total- hip arthroplasty through a posterior approach and for all hip fracture arthroplasty cases

Revision of the femoral component during revision hip arthroplasty may pose significant technical challenges, most notably femoral fracture and bone perforation. The in-cementing technique allows use of the original bone-cement interface which has been proven to be biomechanically stronger than recementing after complete removal of the original cement mantle. This study reviews a series of 54 consecutive revision hip arthroplasty procedures carried out by the senior author using the in-cementing technique from November 1999 to March 2003. Patients were followed up clinically and radiologically with serial outpatient reviews and their functional outcome was assessed using the Harris hip scoring system, the Oxford hip scoring system and the University of California at Los Angeles (UCLA) activity profile. Their physical and mental well-being was also assessed using the SF-36 self-questionnaire. Fifty-four procedures were performed on 51 patients. There were 31 males and 20 females. The average age was 70.3+/-8.1 years (range: 45-83 years). The average time to revision from the original procedure was 132.8+/-59.0 months (range: 26-286 months). The average length of follow-up was 29.2+/-13.4 months (range: 6-51 months) post revision arthroplasty. Two patients suffered dislocations, one of which was recurrent and was revised with a Girdlestone's procedure. No patient displayed any evidence of radiographical loosening. The average Harris hip score of the study group was 85.2+/-11.6 (range: 51.9-98.5). The average Oxford hip score recorded was 19.6+/-7.7 (range: 12-41) and the average UCLA activity profile score was 5.9+/-1.6 (range: 3-8). The SF-36 questionnaire had an average value of 78.0+/-18.3 (range: 31.6-100). In conclusion, the results of this study show excellent clinical and radiological results of the in-cementing technique with high patient satisfaction in terms of functional outcome. This technique merits consideration where possible in revision hip arthroplasty

Objectives. Few studies have assessed outcomes following non-metal-on-metal hip arthroplasty (non-MoMHA) revision surgery performed for adverse reactions to metal debris (ARMD). We assessed outcomes following non-MoMHA revision surgery performed for ARMD, and identified predictors of re-revision. Methods. We performed a retrospective observational study using data from the National Joint Registry for England and Wales. All non-MoMHAs undergoing revision surgery for ARMD between 2008 and 2014 were included (185 hips in 185 patients). Outcome measures following ARMD revision were intra-operative complications, mortality and re-revision surgery. Predictors of re-revision were identified using Cox regression. Results. Intra-operative complications occurred in 6.0% (n = 11) of the 185 cases. The cumulative four-year patient survival rate was 98.2% (95% CI 92.9 to 99.5). Re-revision surgery was performed in 13.5% (n = 25) of hips at a mean time of 1.2 years (0.1 to 3.1 years) following ARMD revision. Infection (32%; n = 8), dislocation/subluxation (24%; n = 6), and aseptic loosening (24%; n = 6) were the most common re-revision indications. The cumulative four-year implant survival rate was 83.8% (95% CI 76.7 to 88.9). Multivariable analysis identified three predictors of re-revision: multiple revision indications (hazard ratio (HR) = 2.78; 95% CI 1.03 to 7.49; p = 0.043); selective component revisions (HR = 5.76; 95% CI 1.28 to 25.9; p = 0.022); and ceramic-on-polyethylene revision bearings (HR = 3.08; 95% CI 1.01 to 9.36; p = 0.047). Conclusions. Non-MoMHAs revised for ARMD have a high short-term risk of re-revision, with important predictors of future re-revision including selective component revision, multiple revision indications, and ceramic-on-polyethylene revision bearings. Our findings may help counsel patients about the risks of ARMD revision, and guide reconstructive decisions. Future studies attempting to validate the predictors identified should also assess the effects of implant design (metallurgy and modularity), given that this was an important study limitation potentially influencing the reported prognostic factors. Cite this article: G. S. Matharu, A. Judge, D. W. Murray, H. G. Pandit. Outcomes following revision surgery performed for adverse reactions to metal debris in non-metal-on-metal hip arthroplasty patients: Analysis of 185 revisions from the National Joint Registry for England and Wales. Bone Joint Res 2017;6:405–413. DOI: 10.1302/2046-3758.67.BJR-2017-0017.R2

Femoral stems with exchangeable necks are a recent development in hip arthroplasty. They are proposed to be better in restoring offset and leg length while not compromising the fixation in the femoral canal. Few studies have been published on the clinical and functional outcome of modular neck hip system. The Australian Joint registry data was analysed to evaluate the outcome after modular neck hip arthroplasties with the diagnosis of primary osteoarthritis. Only prostheses with data for more than 50 patients were studied. The indications for revision were identified. A comparison of outcomes with conventional hip arthroplasties was done. The analysis confirmed that femoral stems with exchangeable necks have a significantly higher risk of revision compared to all other primary total conventional hip replacement (adj HR=2.13; 95% CI (1.88, 2.42), p<0.001). With the exception of three, all femoral stems with exchangeable necks have a higher rate of revision compared to primary total conventional hip replacement. The three exceptions have a short follow up. There is an increased incidence of revision for loosening and dislocation. The recent registry data suggests that with end point being revision, the outcome of exchangeable neck hips are worse than conventional hips in patients with primary osteoarthritis of hip

Introduction. The development of an algorithm that provides accurate individualised estimates of revision risk could help patients make informed surgical treatment choices. This requires building a survival model based on fixed and modifiable risk factors that predict outcome at the individual level. Here we compare different survival models for predicting prosthesis survivorship after hip replacement for osteoarthritis using data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR). Methods. In this comparative study we implemented parametric and flexible parametric (FP) methods and random survival forests (RSF). The overall performance of the parametric models was compared using Akaike information criterion (AIC). The preferred parametric model and the RSF algorithm were further compared in terms of the Brier score, concordance index and calibration via repeated five-fold cross-validation. Results. The dataset contains 327 238 hip replacements for osteoarthritis carried out in England and Wales between 2003 and 2015. The AIC value for the FP model was the lowest. The averages of survival probability estimates are shown in Figure 1. The integrated Brier score of the FP model and the RSF approach over 10 years were similar: 0.011 (95% confidence interval: 0.011–0.011). The concordance index of the FP model at 10 years was 59.4% (95% confidence interval: 59.4%–59.4%). The concordance index was 56.2% (56.1%–56.3%) for the RSF method. Calibration plots for the FP model and the RSF algorithm are presented in Figure 2. Conclusion. The flexible parametric model outperformed other commonly used survival models across chosen validation criteria. However, it does not provide high discriminatory power at the individual level. This might be due to variable outcomes generated by different fixation or bearing types that cannot be captured using a single model. More complex multi-state models may provide better discrimination. For any figures and tables, please contact the authors directly

The number of hip arthroplasty procedures has steadily increased in the United States over the last decade [Wolford, et. al, 2015]. This trend will continue as this treatment is the most effective approach in relieving pain, improving mobility, reducing fall risk and improving the quality of life in patients with end-stage osteoarthritis. The effectiveness of recovery can be impacted by factors such as access to postoperative physical therapy regimens. During the recovery period, it is important for therapists to be guided in their therapeutic decision making by accurate data concerning the patient's performance on a variety of measures. This project is designed to map the gait recovery curves of individuals who have undergone unilateral hip arthroplasty. To date, eight individuals (4 females, mean age 64.9, SD 11.1) have participated in the study. Five of the patients were treated by traditional press-fit Accolade II implants (Stryker, Mahwah, NJ USA) through a direct anterior approach THA and the other three has been treated by using DAA THA and using neck preserving Minihip. TM. short stem implant (Corin Ltd., Cirencester, UK). Each participant walked on an instrumented treadmill as a self-selected speed for three minutes pre-surgery. Post-surgery data collections occurred at three and six weeks, and three and six months and employed the same treadmill speed as used prior to surgery. Bilateral lower limb kinematic data was collected with a 12 camera motion capture system Vicon® (Oxford Metrics, Oxford, UK) using reflective markers attached to the hip, knee, ankle, heel and toe. Force plates embedded in the treadmill provided kinetic data that aided in the detection of heel strike and toe off. The temporal features associated with gait, including stride, stance time and double support time were obtained for both the surgical and non-surgical limbs and were used to assess changes in performance during the recovery period. The stance and double support data were also converted to a percentage of stance values which provide additional insights into gait control strategies. Repeated measure MANOVAs were used to evaluate any potential differences in the variables either between limbs or over time. Results from the statistical testing revealed that there were no significant differences between the two limbs for either stride or stance time. This was expected since global asymmetrical gait would have led to the participants veer off of the treadmill. There was a main effect of ‘Time’ for both stride and stance times. Post hoc testing indicated that the 6-month post-surgery measures were significantly reduced when compared to the Pre-surgery and 3-week post-surgery measures. Similarly, there were no significant differences in double support times between the two legs but there was a main effect for time. Post hoc testing revealed that the 6-month post-surgery double support time was significantly less than the Pre-surgery and 3-week post-surgery measures. These significant changes clearly indicate that surgery is effective in improving gait parameters. Moreover, clinicians may want to consider assessing double support time as this measure is a particularly robust indicator of the effectiveness of unilateral hip arthroplasty

Hip arthroplasty is commonly used as the final treatment approach for patients experiencing end-stage osteoarthritis. The number of these patients needing this treatment is expected to grow significantly by year 2030 to more than 572000 patients [Kurtz et al., 2007]. One of the important outcomes of hip arthroplasty is to improve patients' functions postoperatively. The evaluation of walking can provide a wealth of information regarding the efficiency of this treatment in improving a patient's mobility. Assessing the kinematic features of gait collected with a motion capture system combined with the aid of a motor-driven treadmill provides the advantage of enabling the evaluator to collect precise information about a large number of strides in a short period of time. Body segment kinematics (i.e. joint motion) are most often represented in the form of time series data with the abscissa (X axis) representing time and the ordinate (y axis) representing the motion of a particular joint. Although a great deal of information can be gained from the analyses of time series data, non-linear analyses tools can provide an additional and important dimension to a clinician's assessment of gait recovery. In this study eight patients (4 females, mean age 64.9, SD 11.1) have currently been assessed after unilateral hip arthroplasty. All surgeries were conducted by direct anterior approach by using two different approaches; three of the patients were treated by bone preservation technique and received Minihip short stem implant (Corin Ltd., Cirencester, UK) and five were treated by using a press fit stem implant Accolade II (Stryker, Mahwah, NJ USA). Patients performed a single three-minute trial of walking on a motor-driven treadmill at a self-selected pace. Using a 12 camera system, bilateral lower limb joint motion was collected prior to the surgery, at three and six weeks and at three and 6 months after the surgery. Depending upon the patient's preferred walking pace; between 40 and 45 strides were collected during each trial. Kinematic data obtained from force plates embedded in the treadmill were used to identify the heel strike and toe off events for each stride. After time normalizing the each of the joint angles (i.e. hip, knee, ankle) for each stride to 100 data points the data were then amplitude normalized to the initial point of the pre-surgery data. The non-linear tools of angle-angle and phase plane were used to explore relationships that are not readily apparent with linear wave form analyses. Angle-angle diagrams between a variety of joints angles both within a single limb or bilaterally enabled us to explore segmental coordination patterns and how they changed over the six months after surgery. Phase plane analyses included comparing joint motion relative to the velocity of that motion. This technique provided insights into the nature of the control of the joint. The additional information that results from the use of non-linear analyses provides an additional dimension of that can aide the clinician in understanding the recovery curve. This additional insight can be used to guide therapeutic decision making

Introduction: In patients presenting with an infected hip arthroplasty first-line antibiotics at our institution are Flucloxacillin and Fucidic Acid. It was observed that many patients needed their antibiotic regime changed once sensitivities became known. This was because of resistance to the first-line antimicrobial agents. This raised the question ‘How frequent is Flucloxacillin and Fucidic acid resistance in prosthetic hip infection and is there a more appropriate first-line antibiotic?’. Method: A computerised search of the Belfast Orthopaedic Information System (BOIS) identified all cases of infected hip arthroplasty from October 2001 to April 2005. All microbiology results of these patients were obtained and analysed to determine the infecting organism, sensitivity and resistance to Flucloxacillin, Fucidic acid and Teicoplanin. Results: BOIS identified forty cases of infected hip arthroplasty, 35 primary arthroplasties and 5 revision arthroplasties. Of the 40 patients 36 had positive cultures, 3 had no growth and there was missing data on one patient. Flucloxacillin sensitivity occurred in 25% of patients with 58% resistance. With regard to Fucidic Acid sensitivity was 47 % with 44% resistance. There were no cases of Teicoplanin resistance. Teicoplanin sensitivity occurred in 78% of patients and with analysis by organism susceptibility sensitivity would measure 92% (8% were not tested against Teicoplanin). Discussion: Flucloxacillin resistance is greater than sensitivity in infected hip arthroplasty in this study group. Fucidic Acid sensitivity and resistance are roughly equal. There are no cases of Teicoplanin resistance in our study population and with analysis with respect to the causative organism Teicoplanin sensitivity reaches 92%. It could be suggested therefore that the first-line agents of Flucloxacillin and Fucidic acid are inappropriate and that Teicoplanin may be a better choice

Objective. Failures of internal fixation after intertrochanteric fractures pose great challenge to orthopaedic surgeons. Hip arthroplasty can be a remedy for such failures, however, the selection of femoral stem length is controversial. This study aims to report our experience of managing failed internal fixation after intertrochanteric fractures with standard femoral stem arthroplasty. Methods. A retrospective review of patients who were managed with hip arthroplasty for failed internal fixation after intertrochanteric fractures in the First Affiliated Hospital of Fujian Medical University, P.R. China between January 2001 to December 2013 was performed. Patients’ age, gender, pre- and postoperative Harris Hip Score (HHS), femoral stem types and surgical outcomes were traced and analyzed. Results. 14 patients were included. The average age at the time of internal fixation and hip arthroplasty was 74.6 years old (Range, 56–89) and 75.8 years old (Range, 58–90), respectively. The time duration between internal fixation and hip arthroplasty ranged from 3 to 26 months. 5 were total hip arthroplasty while 9 were hemiarthroplasty. 4 were implanted with long femoral stems while 10 with standard stems, including 4 cementless (SL-PLUS, Smith & Nephew)and 6 cemented stems. Standard femoral stems were defined as ones that are designed to be used in primary hip replacement, with the length of which ranging from 120 to 140mm. The distal ends of these stems did not exceed the distal screw hole levels of 2 cortical diameters. After a mean follow-up time of 6.4 years (Range, 1–13), 2 patients lost to follow-up and 2 died of non-surgically related diseases. For the 8 cases with standard stems, at the latest follow-up, no periprosthetic fractures or periprosthetic joint infections were observed. A total of 3 hip dislocations happened in 2 patients but were managed successfully with manipulative reduction followed by hip brace. The HHS score increased from an average of 35.6 preoperatively to 79.4 after surgery. Conclusions. Hip arthroplasty can be performed as revision for failed internal fixation after intertrochanteric fractures. Use of standard femoral stems is less invasive, reduces expenditure and can also achieve similar satisfactory clinical outcomes as long femoral stems. However, the long-term clinical outcomes required further follow-up

This study aimed to examine the changing trends in the reasons for total hip replacement (THR) revision surgery, in one country over a twenty-one year period, in order to assess whether changes in arthroplasty practices have impacted revision patterns and whether an awareness of these changes can be used to guide clinical practice and reduce future revision rates.

The reason for revision THR performed between January 1999 and December 2019 was extracted from the New Zealand Joint Registry (NZJR). The results were then grouped into seven 3-year periods to allow for clearer visualization of trends. The reasons were compared across the seven time periods and trends in prosthesis use, patient age, gender, BMI and ASA grade were also reviewed. We compared the reasons for early revision, within one year, with the overall revision rates.

There were 20,740 revision THR registered of which 7665 were revisions of hips with the index procedure registered during the 21 year period. There has been a statistically significant increase in both femoral fracture (4.1 – 14.9%, p<0.001) and pain (8.1 – 14.9%, p<0.001) as a reason for hip revision. While dislocation has significantly decreased from 57.6% to 17.1% (p<0.001). Deep infection decreased over the first 15 years but has subsequently seen further increases over the last 6 years. Conversely both femoral and acetabular loosening increased over the first 12 years but have subsequently decreased over the last 9 years. The rate of early revisions rose from 0.86% to 1.30% of all revision procedures, with a significant rise in revision for deep infection (13-33% of all causes, p<0.001) and femoral fracture (4-18%, p<0.001), whereas revision for dislocation decreased (59-30%, p<0.001). Adjusting for age and gender femoral fracture and deep infection rates remained significant for both (p<0.05). Adjusting for age, gender and ASA was only significant for infection.

The most troubling finding was the increased rate of deep infection in revision THR, with no obvious linked pattern, whereas, the reduction in revision for dislocation, aseptic femoral and acetabular loosening can be linked to the changing patterns of the use of larger femoral heads and improved bearing surfaces.