Purpose. Exeter stem was introduced to Japanese market at 1996. Since then, owing to its excellent clinical results, the number of the stem used has been increased year by year and more than 2000 stems have been implanted during the year 2009. The present study aims to prove its efficacy for Japanese patients by evaluating short term results of four major dedicated hip centers. Method. We present the short-term multi-center results of primary THA with Exeter stem combined with modern cementing technique in 881 patients (1000 hips). The average age of the patients at operation was 62.3years (ranging 23 to 89 years). Mean postoperative follow up period was 4.0 (ranging 2 to 9) years. Results. Intraoperative complications such as femoral fracture were observed in 6 hips. Postoperative cementing grade using Barrack's classification was judged as A for 735 hips, as B for 246 hips, and as C for 4 hips, respectively. Twenty-four patients died with unrelated disease and 52 patients were lost during follow-up period. Follow-up ratio was 94.8%. Thirty postoperative complications which include 9 infections, 14 dislocations, 5 deep vein thrombosis, and 2 sciatic nerve palsies were observed. Symptomatic pulmonary embolization or femoral fracture was not observed. Re-operations for infection and dislocation were performed for 8 and 6 hips, respectively. At the final follow-up, no radiolucent line at bone-cement interface was observed. Cortical hypertrophy was observed in 9.6% at Gruen zone 2 to 6. Kaplan-Meier survivorship analysis predicted a rate of survival at 5 years of 100% with radiolucent line at bone-cement interface of the femur as the endpoint, and of 98.8% when re-operation for any reason was used. Conclusion. The present study revealed excellent short-term result was obtained using Exeter stem combined with modern cementing technique for primary THAs in Japan

Aims. Waiting times for arthroplasty surgery in Northern Ireland are among the longest in the NHS, which have been further lengthened by the onset of the COVID-19 global pandemic in March 2020. The Department of Health in Northern Ireland has announced a new Elective Care Framework (ECF), with the framework proposing that by March 2026 no patient will wait more than 52 weeks for inpatient/day case treatment. We aimed to assess the feasibility of achieving this with reference to total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods. Mathematical modelling was undertaken to calculate when the ECF targets will be achieved for THA and TKA, as well as the time when waiting lists for THA and TKA will be cleared. The number of patients currently on the waiting list and percentage operating capacity relative to pre-COVID-19 capacity was used to determine future projections. Results. As of May 2021, there were 3,757 patients awaiting primary THA and 4,469 patients awaiting primary TKA in Northern Ireland. Prior to April 2020, there were a mean 2,346 (2,085 to 2,610) patients per annum boarded for primary THA, a mean 2,514 (2,494 to 2,514) patients per annum boarded for primary TKA, and there were a mean 1,554 primary THAs and 1,518 primary TKAs performed per annum. The ECF targets for THA will only be achieved in 2030 if operating capacity is 200% of pre COVID-19 pandemic capacity and in 2042 if capacity is 170%. For TKA, the targets will be met in 2034 if capacity is 200% of pre-COVID-19 pandemic capacity. Conclusion. This modelling demonstrates that, in the absence of major funding and reorganization of elective orthopaedic care, the targets set out in the ECF will not be achieved with regard to THA and TKA. Waiting times for THA and TKA surgery in Northern Ireland are likely to remain greater than 52 weeks for most of this decade. Cite this article: Bone Jt Open 2022;3(4):302–306

Aims. Computer-assisted 3D preoperative planning software has the potential to improve postoperative stability in total hip arthroplasty (THA). Commonly, preoperative protocols simulate two functional positions (standing and relaxed sitting) but do not consider other common positions that may increase postoperative impingement and possible dislocation. This study investigates the feasibility of simulating commonly encountered positions, and positions with an increased risk of impingement, to lower postoperative impingement risk in a CT-based 3D model. Methods. A robotic arm-assisted arthroplasty planning platform was used to investigate 11 patient positions. Data from 43 primary THAs were used for simulation. Sacral slope was retrieved from patient preoperative imaging, while angles of hip flexion/extension, hip external/internal rotation, and hip abduction/adduction for tested positions were derived from literature or estimated with a biomechanical model. The hip was placed in the described positions, and if impingement was detected by the software, inspection of the impingement type was performed. Results. In flexion, an overall impingement rate of 2.3% was detected for flexed-seated, squatting, forward-bending, and criss-cross-sitting positions, and 4.7% for the ankle-over-knee position. In extension, most hips (60.5%) were found to impinge at or prior to 50° of external rotation (pivoting). Many of these impingement events were due to a prominent ischium. The mean maximum external rotation prior to impingement was 45.9° (15° to 80°) and 57.9° (20° to 90°) prior to prosthetic impingement. No impingement was found in standing, sitting, crossing ankles, seiza, and downward dog. Conclusion. This study demonstrated that positions of daily living tested in a CT-based 3D model show high rates of impingement. Simulating additional positions through 3D modelling is a low-cost method of potentially improving outcomes without compromising patient safety. By incorporating CT-based 3D modelling of positions of daily living into routine preoperative protocols for THA, there is the potential to lower the risk of postoperative impingement events. Cite this article: Bone Jt Open 2023;4(6):416–423

Aims

The aim of this study was to assess medium-term improvements following total hip arthroplasty (THA), and to evaluate what effect different preoperative Oxford Hip Score (OHS) thresholds for treatment may have on patients’ access to THA and outcomes.

Angular proximal femoral deformities increase the technical complexity of primary total hip arthroplasties (THAs). The goals were to determine the long-term implant survivorship, risk factors, complications, and clinical outcomes of contemporary primary THAs in this difficult cohort. Our institutional total joint registry was used to identify 119 primary THAs performed in 109 patients with an angular proximal femoral deformity between 1997 and 2017. The deformity was related to previous femoral osteotomy in 85%, and developmental or metabolic disorders in 15%. 53% had a predominantly varus angular deformity. The mean age was 44 years, mean BMI was 29 kg/m. 2. , and 59% were female. An uncemented metaphyseal fixation stem was used in 30%, an uncemented diaphyseal fixation stem in 28%, an uncemented modular body stem with metaphyseal fixation sleeve in 24%, and a cemented stem in 18%. Simultaneous corrective femoral osteotomy was performed in 18%. Kaplan-Meier survivorships and Harris hip scores were reported. Mean follow-up was 8 years. The 10-year survivorships free of femoral loosening, aseptic femoral revision, any revision, and any reoperation were 95%, 93%, 90% and 88%, respectively. Revisions occurred in 13 hips for: aseptic femoral component loosening (3), stem fracture (2), dislocation (2), aseptic acetabular loosening (2), polyethylene liner exchange (2), and infection (2). Preoperative varus angular deformities were associated with a higher risk of any revision (HR 10, p=0.03), and simultaneous osteotomies with a higher risk of any reoperation (HR 3.6, p=0.02). Mean Harris hip scores improved from 52 preoperatively to 82 at 10 years (p<0.001). In the largest series to date of primary THAs in patients with angular proximal femoral deformities, we found a good 10-year survivorship free from any revision. Varus angular deformities, particularly those treated with a simultaneous osteotomy due to the magnitude or location of the deformity, had a higher reoperation rate. Keywords: Proximal femoral deformity; dysplasia; femoral osteotomy; survivorship; revision. Level of evidence: Level III, comparative retrospective cohort

Background and purpose. Previous publications have reported an increased but levelling out risk of revision for infection after total hip arthroplasty (THA) in Norway. We assessed the changes in risk of major (cup and/or stem, 1- or 2-stage) and minor revisions (debridement, exchange of modular parts, antibiotics and implant retention (DAIR)) for infection after primary THAs reported to the Norwegian Arthroplasty Register (NAR) over the period 2005-2022. Patients and methods. Primary THAs reported to the NAR from 2005 to 2022 were included. Time was stratified into time periods (2005-2009, 2010-2018, 2019-2022) based on a previous publication. Cox regression analyses, adjusted for sex, age and ASA-classification, with the first revision for infection were performed. Results. 140,338 primary THAs met the inclusion criteria. 1.3% (1,785) were revised for infection during the study period. 0.5% (638) had major revisions, whereas 0.8% (1,147) had DAIRs for infection. The risk of revision for infection was 1.2 (95%CI 1.1-1.4) for 2010-2018 and 1.0 (0.8-1.1) for 2019-2022 compared to 2005-2009. Compared to 2010-2018, the risk of revision for infection was 0.8 (0.7-0.9) for 2019-2022. The risk of DAIR for infection was 1.5 (1.3-1.9) for 2010-2018 and 1.2 (1.0-1.4) for 2019-2022 compared to 2005-2009. Compared to 2010-2018, the risk of DAIR for infection was 0.8 (0.7-0.9) for 2019-2022. The risk of major revision for infection was 0.8 (0.7-1.0) for 2010-2018 and 0.8 (0.6-1.0) for 2019-2022 compared to 2005-2009. Interpretation. The overall risk of revision for infection after THA, in Norway, has decreased in the period 2019-2022. The risk for DAIR initially increased in the period 2005-2009, levelled out 2010-2018 before starting to decrease in 2019-2022. The risk of major revision for infection was reduced in the period 2005-2009 before levelling out. This shows changes in revision strategies, but may also reflect a true decrease in periprosthetic joint infection

Periprosthetic femur fracture (PFF) is a major complication following total hip arthroplasty (THA) that carries significant morbidity, mortality, and economic burden. Currently, uncemented stems are highly preferred in primary THA, but have been associated with higher risk of PFF compared to cemented stems. The use of collared stems in uncemented primary THA has shown promise in reducing PFF rates postoperatively. This retrospective study included 2,294 uncemented primary THAs using the posterior approach performed by two attending surgeons from January 2016 to December 2022. Both surgeons switched from a collarless femoral stem design to a collared design in May 2020. Data was collected regarding stem design, frequency of PFF, and requirement for revision surgery. Periprosthetic fractures were identified and confirmed using medical records and/or radiographic imaging. Fracture rates and percentages between collared and collarless stems were then analyzed. A Fisher's Exact Test was performed to determine if there was a significant association between collared and collarless stem use on PFF rates. A total of 2,294 uncemented primary THAs performed by 2 surgeons were eligible for analysis. 903 (39.4%) patients received a collared stem, and 1,391 (60.6%) patients received a collarless stem. In total, 14 (0.6%) PFFs occurred over the study period. There was 1 fracture (0.1%) out of 903 collared stems, and 13 fractures (0.9%) out of 1,391 collarless stems (p = 0.012). Collared stems were associated with a significant decrease in PFF rate when compared to collarless stems in uncemented primary THA. Future studies are encouraged to continue to investigate PFF and other complication rates with the use of a collared stem design

The Exeter V40 femoral stem is the most implanted stem in the NJR for primary THA. In 2004, the 44/00/125 stem was released for use in “cement-in-cement” revision cases. It has however been used ‘off-label’ as a primary stem when, for example, patient anatomy requires a smaller stem with a 44mm offset. We aimed to investigate survival of this stem in comparison to others in the range when used in primary THAs recorded in the NJR. Analyses were performed using a dataset based on that used for the 2020 NJR annual report. Our exposure was the stem; the outcome was all-cause construct revision. Crude analyses were performed using Kaplan-Meier and adjusted using Cox models. The 44/00/125 stem was directly compared to other stems in the Exeter range. We analysed 330,732 primary THAs using the Exeter V40 stem comprising 34.5% of the 958,869 THAs with complete information from the start of the NJR to 31 December 2018. The 44/00/125 stem was implanted in 2,158 primary THAs with 67.5% in female patients and a mean age of 67.8. The 10-year revision estimate for the 44/00/125 stem was 4.9% (95%CI 3.6, 6.8) and in constructs using an Exeter V40 stem was 2.8% (95%CI 2.7, 2.8). Controlling for age, sex and ASA demonstrated an increased overall hazard of revision for constructs using the 44/00/125 stem compared to constructs using other Exeter V40 femoral stems (HR 1.8 (95%CI 1.4, 2.3)). Although the revision estimate is within the NICE 10-year benchmark, survivorship of constructs using the 44/00/125 stem appears to be lower than the rest of the Exeter V40 range. Attempts to control for age, sex and ASA will not take into account confounding by indication i.e. patients with more complex anatomy who may have a higher risk of revision. Surgeons and patients should be reassured by this but should be aware of the observed increased revision estimate and use the stem according to its indications

Aim. Previous publications have suggested that the incidence of revisions due to infection after THA is increasing. We performed updated time-trend analyses of risk and timing of revision due to infection after primary THAs in the Nordic countries during the period 2004–2018. Methods. 569,463 primary THAs reported to the Nordic Arthroplasty Register Association from 2004 through 2018 were studied. We estimated adjusted hazard ratios (aHR) with 95% confidence interval by Cox regression with the first revision due to infection after primary THA as endpoint. The risk of revision was investigated. In addition, we explored changes in the time span from primary THA to revision due to infection. Results. 5,653 (1.0%) were revised due to infection. The risk of revision due to infection increased through the study period. Compared to the period 2004–2008, the aHRs were 1.4 (95%CI 1.3–1.5) for 2009–2013, and 1.9 (1.7–2.0) for 2014–2018. We found an increased risk in all four Nordic countries. Compared to 2004–2008, the aHR due to infection 0–30 days after THA was 2.5 (2.1–2.9) for 2009–2013 and 3.4 (3.0–3.9) for 2013–2018. The aHR of revision due to infection 31–90 days after THA was 1.5 (1.3–1.9) for 2009–2013 and 2.5 (2.1–3.0) for 2013–2018, compared to 2004–2008. Beyond 91 days after THA, the risk of revision due to infection was stable over the whole study period. Interpretation. The risk of revision due to deep infection after THA nearly doubled throughout the period 2004–2018. This increase was mainly due to an increased risk of early revisions. The cause for these changes may be multifactorial (patient selection, diagnostics, revision strategy, completeness of reporting, etc.), are not possible to disclose in the present study, and warrants further research

Aims. Implant waste during total hip arthroplasty (THA) represents a significant cost to the USA healthcare system. While studies have explored methods to improve THA cost-effectiveness, the literature comparing the proportions of implant waste by intraoperative technology used during THA is limited. The aims of this study were to: 1) examine whether the use of enabling technologies during THA results in a smaller proportion of wasted implants compared to navigation-guided and conventional manual THA; 2) determine the proportion of wasted implants by implant type; and 3) examine the effects of surgeon experience on rates of implant waste by technology used. Methods. We identified 104,420 implants either implanted or wasted during 18,329 primary THAs performed on 16,724 patients between January 2018 and June 2022 at our institution. THAs were separated by technology used: robotic-assisted (n = 4,171), imageless navigation (n = 6,887), and manual (n = 7,721). The primary outcome of interest was the rate of implant waste during primary THA. Results. Robotic-assisted THA resulted in a lower proportion (1.5%) of implant waste compared to navigation-guided THA (2.0%) and manual THA (1.9%) (all p < 0.001). Both navigated and manual THA were more likely to waste acetabular shells (odds ratio (OR) 4.5 vs 3.1) and polyethylene liners (OR 2.2 vs 2.0) compared to robotic-assisted THA after adjusting for demographic and perioperative factors, such as surgeon experience (p < 0.001). While implant waste decreased with increasing experience for procedures performed manually (p < 0.001) or with navigation (p < 0.001), waste rates for robotic-assisted THA did not differ based on surgical experience. Conclusion. Robotic-assisted THAs wasted a smaller proportion of acetabular shells and polyethylene liners than navigation-guided and manual THAs. Individual implant waste rates vary depending on the type of technology used intraoperatively. Future studies on implant waste during THA should examine reasons for non-implantation in order to better understand and develop methods for cost-saving. Cite this article: Bone Jt Open 2024;5(8):715–720

It is not unusual for patients prior to their total hip arthroplasty (THA) to indicate that their symptoms worsen with certain meteorological conditions. However, the prevalence and evolution of weather-related pain (WRP) following THA remain poorly understood. The aim of this study was to investigate the prevalence of WRP both before and after primary THA, to assess the impact of THA on pre-existing WRP, and to identify potential risk factors associated with WRP. An in-person survey was conducted on 442 primary THAs, in 327 consecutive patients at the time of their postoperative follow-up. Each patient was assessed using a questionnaire specifically designed to address weather-related joint pain before and after their THA. The clinical evaluation included patient-reported outcome scores (PROMS). Preoperatively, 17% of THA hips experienced WRP, with 71% achieving complete resolution postoperatively (p < 0.001). In patients with WRP in multiple joints and their hip, the THA failed to alleviate the WRP in 31% of the cases. In addition, 8% of the THA patients developed de-novo WRP after surgery. Although the overall prevalence of WRP in hips post-THA was 12%, the prevalence was 29% in hips with WRP preoperatively and 31% in the hips of patients with WRP in multiple joints as well as their hip. WRP in other joints, the initial diagnosis, body mass index (BMI), and age were correlated with WRP following THA. WRP is not uncommon prior to and after THA. Although THA can effectively alleviate WRP in specific patient populations, it does not universally eliminate preoperative WRP or prevent the emergence of new WRP after surgery

Short cementless femoral stems are increasingly popular as they allow for less dissection for insertion. Use of such stems with the anterior approach (AA) may be associated with considerable per-operative fracture risk. This study's primary aim was to evaluate whether patient-specific femoral- and pelvic- morphology and surgical technique, influence per-operative fracture risk. In doing so, we aimed to describe important anatomical thresholds alerting surgeons. This is a single-center, multi-surgeon retrospective, case-control matched study. Of 1145 primary THAs with a short, cementless stem inserted via the AA, 39 periprosthetic fractures (3.4%) were identified. These were matched for factors known to increase fracture risk (age, gender, BMI, side, Dorr classification, stem offset and indication for surgery) with 78 THAs that did not sustain a fracture. Radiographic analysis was performed using validated software to measure femoral- (canal flare index [CFI], morphological cortical index [MCI], calcar-calcar ratio [CCR]) and pelvic- (Ilium-ischial ratio [IIR], ilium overhang, and ASIS to greater trochanter distance) morphologies and surgical technique (% canal fill). Multivariate and Receiver-Operator Curve (ROC) analysis was performed to identify predictors of fracture. Femoral factors that differed included CFI (3.7±0.6 vs 2.9±0.4, p3.17 and II ratio>3 (OR:29.2 95%CI: 9.5–89.9, p<0.001). Patient-specific anatomical parameters are important predictors of fracture-risk. When considering the use of short stems via the AA, careful radiographic analysis would help identify those at risk in order to consider alternative stem options

Background. Increasing evidence suggests a link between the bearing surface used in total hip arthroplasty (THA) and the occurrence of infection. It is postulated that polyethylene has immunomodulatory effects and may influence bacterial function and survival, thereby impacting the development of periprosthetic joint infection (PJI). This study aimed to investigate the association between polyethylene type and revision surgery for PJI in THA using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). We hypothesized that the use of XLPE would demonstrate a statistically significant reduction in revision rates due to PJI compared to N-XLPE. Methods. Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) spanning September 1, 1999, to December 31, 2021, were used to compare the infection revision rates between THA using N-XLPE and XLPE. We calculated the Cumulative Percentage Revision rate (CPR) and Hazard Ratio (HR) while controlling for factors like age, sex, body mass index (BMI), American Society of Anesthesiologists’ (ASA) grade, and head size. Results. From the total 361,083 primary THAs, 26,827 used N-XLPE and 334,256 used XLPE. Excluding data from the first 6 months post-surgery, 220 revisions occurred in the N-XLPE group and 1,055 in the XLPE group for PJI. The HR for infection revision was significantly higher in N-XLPE compared to XLPE, at 1.64 (95% CI, 1.41–1.90, p<0.001). Conclusions. This analysis provides evidence of an association between N-XLPE and revision for infection in THA. We suspect that polyethylene wear particles contribute to the susceptibility of THA to PJI, resulting in a significantly higher risk of revision for infection in N-XLPE hips compared to those with XLPE. Level of Evidence. Therapeutic Level III

Proponents of the direct anterior approach (DAA) for hip arthroplasty (THA) claim lower postoperative pain compared to the posterolateral approach (PA); however, whether that theoretical advantage results in lower opioid consumption is unclear. We sought to investigate the relationship between the DAA and PA on total 90-day predicted opioid consumption in a large cohort. Retrospective analysis identified 2,304 DAA and 6,288 PA primary THAs in patients >18 years old from February 2019 to April 2022. Ninety-day postoperative total morphine milligram equivalent (MME); in-hospital administration, discharge prescriptions, and refills within 90 days were compared between DAA and PA cohorts. Nearest-neighbor matching was performed controlling for age, sex, BMI, ASA, and periarticular injection to evaluate opioid consumption patterns for DAA and PA. Quantile regression was employed to predict the median (50th percentile) MME prescribed by surgical approach. After matching, DAA and PA demonstrated similar median total 90-day prescribed MME (p = 0.008). After adjusting for patient and surgical factors, quantile regression predicted a similar median total 90-day prescribed MME for DAA and PA (243.5 versus 242.7; p = 0.78). While approach did not demonstrate a significant relationship for predicted 90-day MME, other factors including age, sex, BMI, length of stay, peripheral anesthesia, periarticular injection, and white or Caucasian race demonstrated a significant relationship with predicted 90-day MME (p <0.0001). While we identified several risk factors for increased in-hospital and 90-day post-operative opioid consumption, a comparison between DAA and PA did not demonstrate significantly different opioid prescribing patterns

Controversy persists over whether cemented or uncemented fixation is more effective in reducing revision and mortality risks following primary total hip arthroplasty (THA). Despite a shift towards uncemented THA in Europe, Australia, and the US, no consensus exists on superior outcomes. This ambiguity in evidence from randomized controlled trials (RCTs) and observational studies necessitates advanced research methodologies to derive more definitive conclusions. This study investigates the causal impact of THA fixation type on 2-year and 5-year revision rates, along with 90-day mortality, utilizing a regression discontinuity (RD) design in scenarios where fixation choice is guided by patient age. Employing data from the Dutch Arthroplasty Register, we conducted a cohort study on primary THAs for osteoarthritis from 2007 to 2019. A “fuzzy” RD design was executed to compute the Local Average Treatment Effect for subjects around the age-based selection threshold for fixation type. The main outcome of interest was the revision rate at 2 years post-operation. Analysis for the 2-year revision endpoint, covering any cause, included 2,344 females and 1,671 males across 5 hospitals each, with no significant variation in revision rates observed. For the 5-year mark, 1,058 females in 3 hospitals and 214 males in 1 hospital were examined, similarly showing no significant differences. Mortality within 90 days post-operation was also investigated in 5 female and 7 male cohorts, with 2,180 and 2,145 surgeries respectively, yielding no substantial disparities. In conclusion, the RD analysis revealed no notable differences in revision rates at 2 and 5 years or in early mortality based on the fixation method used in THA. These outcomes suggest that the age-based preference for THA fixation may not influence the revision or mortality risk, underscoring the value of RD design in deriving causal insights from observational data

Periprosthetic femoral fractures (PFFs) remain a major concern following cementless total hip arthroplasty (THA). This study aimed to evaluate the association between different types of cementless tapered stems and the risk of postoperative PFF. A retrospective review of primary THAs performed at a single center from January 2011 to December 2018 included 3,315 hips (2,326 patients). Cementless stems were classified according to their design geometry using the system proposed by Radaelli et al. The incidence of PFF was compared between flat taper porous-coated stems (type A), rectangular taper grit-blasted stems (type B1), and quadrangular taper hydroxyapatite-coated stems (type B2). Multivariate regression analyses were performed to identify independent factors related to PFF. The mean follow-up duration was 61 months (range, 12‒139 months). Overall, 45 (1.4%) postoperative PFFs occurred. The incidence of PFF was significantly higher in type B1 stems than in type A and type B2 stems (1.8 vs. 0.7 vs. 0.7%; P=0.022). Additionally, more surgical treatments (1.7 vs. 0.5 vs. 0.7%; P=0.013) and femoral revisions (1.2 vs. 0.2 vs. 0%; P=0.004) were required for PFF in type B1 stems. After controlling for confounding variables, older age (P<0.001), diagnosis of hip fracture (P<0.001), and use of type B1 stems (P=0.001) were significant factors associated with PFF. Type B1 rectangular taper stems were found to have higher risks for postoperative PFF and PFF requiring surgical management than type A and type B2 stems in THA. Femoral stem geometry should be considered when planning for cementless THA in elderly patients with compromised bone quality

Patients with a high comorbidity burden (high-risk) can achieve similar improvements in quality of life compared to low-risk patients, but greater morbidity may deter surgeons from operating on these patients. Whether surgeon volume influences THA outcomes in high-risk patients has not been investigated. This study aimed to compare complication rates and implant survivorship in high-risk patients operated on by high volume (HV) and non-HV THA surgeons. Patients with Charlson Comorbidity Index ≥ 5 and American Society of Anesthesiologist Classification of 3 or 4 undergoing primary, elective THA between 2013 and 2021 were retrospectively reviewed. Patients were separated into groups based on whether they were operated on by a HV surgeon (defined as the top 25% of surgeons at our institution by number of primary THAs per year) or a non-HV surgeon. Groups were propensity matched 1:1 to control for demographic variables. A total of 1,134 patients were included in the matched analysis. Ninety day readmissions and revisions were compared between groups, and Kaplan-Meier analysis was used to evaluate implant survivorship within the follow-up period. Years of experience were comparable between Non-HV and HV surgeons (p=0.733). The HV group had significantly shorter surgical times (p<0.001), and shorter length of stay (p=0.009) compared to the Non-HV group. The HV group also had significantly fewer 90-day readmissions (p=0.030), all-cause revisions (p=0.023) and septic revisions (p=0.020) compared to the non-HV group at latest follow-up. The HV group had significantly greater freedom from all-cause (p=0.023) and septic revision (p=0.020) compared to the non-HV group. High-risk THA patients have fewer 90-day readmissions, all-cause revisions, septic revisions, as well as shorter length of stay when treated by HV surgeons. THA candidates with a high comorbidity burden may benefit from referral to high-volume surgeons to reduce procedural risk and improve postoperative outcomes

Aim. Two types of national registers surveil infections after primary total hip arthroplasty (THA) in Norway: The National surveillance system for surgical site infections (NOIS) that surveil all primary THAs 30 days postoperatively for surgical site infections (SSI), and the Norwegian Arthroplasty Register (NAR) that follow all THAs until any surgical reoperation/revision or the death of the patient. Since these registers report on the same THAs we assessed correspondence between and time trends for the two registers in period 2013 to 2022. All reported THAs were included. Method. The THAs were matched on a group level according to sex, age and ASA-class. In addition to descriptive statistics, adjusted Cox regression analyses were performed with adjustment for sex, age group (<45, 45-54, 55-64, 65-74, 75-84, >85 years) and ASA-class (1, 2, 3, 4 and missing). Changes in annual incidence and adjusted hazard rate (aHR) was calculated. Endpoints in the NOIS were 30-Days SSI and 30-Days reoperation for SSI. Endpoints in the NAR were 30-Days and 1-Year reoperation for periprosthetic joint infection (PJI). Results. The NOIS had registered 87,923 THAs with 1,393 (1.58%) SSIs and 765 (0.87%) reoperations for SSI within 30 postoperatively. The NAR had registered 91,194 THAs with 725 (0.80%) reoperations for infection after 30 days, and 1,019 (1.21%) reoperations for infections after one year. The distribution of sex, age and ASA-class was near identical in the two registers. There was a mean annual reduction in risk of both SSI (aHR 0.92 (95% CI 0.90-0.93)) and reoperation for SSI (0.95(0.92-0.97)) and PJI (30-Days: 0.96 (0.94-0.99), 1-Year: 0.95-0.99)) over the period 2013-2022. Conclusions. The NOIS and the NAR have excellent completeness and the registrations in both registers may be considered representative for the Norwegian population. Not all SSI are reoperated. The incidence and risk of SSI (NOIS) and reoperation for PJI (NAR) is declining and may reflect a true reduction in incidence of PJI after primary THA

Total hip arthroplasty (THA) is an effective treatment for symptomatic hip osteoarthritis (OA). While computer-navigation technologies in total knee arthroplasty show survivorship advantages and are widely used, comparable applications within THA show far lower utilisation. Using national registry data, this study compared patient reported outcome measures (PROMs) in patients who underwent THA with and without computer navigation. Data from Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) PROMs program included all primary THA procedures performed for OA up to 31 December 2020. Procedures using the Intellijoint HIP® navigation system were identified and compared to procedures using other computer navigation systems or conventional instrumentation only. Changes in PROM scores between pre-operative and 6-month post-operative time points were analysed using multiple regression model, adjusting for pre-operative score, patient age, gender, ASA score, BMI, surgical approach, and hospital type. There were 65 primary THA procedures that used the Intellijoint HIP® system, 90 procedures used other types of computer navigation, and the remaining 5,284 primary THA procedures used conventional instrumentation. The estimated mean changes in the EuroQol visual analogue scale (EQ VAS) score and Oxford Hip score did not differ significantly when Intellijoint® was compared to conventional instruments (estimated differences of 2.4, 95% CI [-1.7, 6.5], p = 0.245, and −0.5, 95% CI [-2.5, 1.4], p = 0.592, respectively). The proportion of patients who were satisfied with their procedure was also similar when Intellijoint® was compared to conventional instruments (rate ratio 1.06, 95% CI [0.97, 1.16], p = 0.227). The preliminary data demonstrate no significant difference in PROMs when comparing the Intellijoint HIP® THA navigation system with both other navigation systems and conventional instrumentation for primary THAs performed for OA. Level of evidence: III (National registry analysis)

Total hip arthroplasty (THA) is an effective treatment for symptomatic hip osteoarthritis (OA). Computer-navigation technologies in total knee arthroplasty show evidence-supported survivorship advantages and are used widely. The aim of this study was to determine the revision outcome of hip commercially available navigation technologies. Data from the Australian Orthopaedic Association National Joint Replacement Registry from January 2016 to December 2020 included all primary THA procedures performed for osteoarthritis (OA). Procedures using the Intellijoint HIP® navigation were identified and compared to procedures inserted using ‘other’ computer navigation systems and to all non-navigated procedures. The cumulative percent revision (CPR) was compared between the three groups using Kaplan-Meier estimates of survivorship and hazard ratios (HR) from Cox proportional hazards models, adjusted for age and gender. A prosthesis specific analysis was also performed. There were 1911 procedures that used the Intellijoint® system, 4081 used ‘other’ computer navigation, and 160,661 were non-navigated. The all-cause 2-year CPR rate for the Intellijoint HIP® system was 1.8% (95% CI 1.2, 2.6), compared to 2.2% (95% CI 1.8, 2.8) for other navigated and 2.2% (95% CI 2.1, 2.3) for non-navigated cases. A prosthesis specific analysis identified the Paragon/Acetabular Shell THAs combined with the Intellijoint HIP® system as having a higher (3.4%) rate of revision than non-navigated THAs (HR = 2.00 (1.01, 4.00), p=0.048). When this outlier combination was excluded, the Intellijoint® system group demonstrated a two-year CPR of 1.3%. There was no statistical difference in the CPR between the three groups before or after excluding Paragon/Acetabular Shell system. The preliminary data presented demonstrate no statistical difference in all cause revision rates when comparing the Intellijoint HIP® THA navigation system with ‘other’ navigation systems and ‘non-navigated’ approaches for primary THAs performed for OA. The current sample size remains too small to permit meaningful subgroup statistical comparisons