Aims. Several short- and mid-term studies have shown minimal liner wear of highly cross-linked polyethylene (HXLPE) in total hip arthroplasty (THA), but the safety of using thinner HXLPE liners to maximize femoral head size remains uncertain. The objective of this study was to analyze clinical survival and radiological wear rates of patients with HXLPE liners, a 36 mm femoral head, and a small acetabular component with a minimum of ten years’ follow-up. Methods. We retrospectively identified 55 patients who underwent primary THA performed at a single centre, using HXLPE liners with 36 mm cobalt-chrome heads in acetabular components with an outer diameter of 52 mm or smaller. Patient demographic details, implant details, death, and all-cause revisions were recorded. Cox regression and Kaplan-Meier survival was used to determine all-cause and liner-specific revision. Of these 55 patients, 22 had a minimum radiological follow-up of seven years and were assessed radiologically for linear and volumetric wear. Results. Overall survival rate for all-cause revision was 94.5% (95% confidence interval (CI) 81.7% to 97.2%) at a mean follow-up of 12.8 years (10.9 to 18.7). Three patients were revised, none for liner wear, fracture, or dissociation. A total of 22 patients were included in the radiological analysis (mean follow-up 9.9 years (7.5 to 13.7)). Mean linear liner wear was 0.085 mm (95% CI -0.086 to 0.257) and the volumetric wear rate was 11.097 mm. 3. /year (95% CI -6.5 to 28.7). Conclusion. Using HXLPE liners with 36 mm heads in 52 mm acetabular components or smaller is safe, with excellent survival and low rates of linear and volumetric wear at medium-term follow-up. Patients did not require revision surgery for liner complications such as fracture, dissociation, or wear. Our results suggest that the advantages of using larger heads outweigh the potential risks of using thin HXLPE liners. Cite this article: Bone Joint J 2023;105-B(1):29–34

Aims. The aims of this study were to determine if an increasing serum cobalt (Co) and/or chromium (Cr) concentration is correlated with a decreasing Harris Hip Score (HHS) and Hip disability and Osteoarthritis Outcome Score (HOOS) in patients who received the Articular Surface Replacement (ASR) hip resurfacing arthroplasty (HRA), and to evaluate the ten-year revision rate and show if sex, inclination angle, and Co level influenced the revision rate. Methods. A total of 62 patients with an ASR-HRA were included and monitored yearly postoperatively. At follow-up, serum Co and Cr levels were measured and the HHS and the HOOS were scored. In addition, preoperative patient and implant variables and the need for revision surgery were recorded. We used a linear mixed model to relate the serum Co and Cr levels to different patient-reported outcome measures (PROMs). For the survival analyses we used the Kaplan-Meier and Cox regression model. Results. We found that an increase of one part per billion (ppb) in serum Co and Cr levels correlated significantly with worsening of the HHS in the following year. This significant correlation was also true for the HOOS-Pain and HOOS-quality of life sub scores. The overall ten-year survival rate in our cohort was 65% (95% confidence interval (CI) 52.5 to 77.6). Cox regression analysis showed a significant hazard ratio (HR) of 1.08 (95% CI 1.01 to 1.15; p = 0.028) for serum Co level. No significance was found with sex or inclination angle. Conclusion. This study shows that increasing serum Co and Cr levels measured in patients with an ASR-HRA are predictive for deterioration in HHS and HOOS subscales in the following year. Increasing serum Co and Cr should forewarn both surgeon and patient that there is a heightened risk of failure. Continued and regular review of patients with an ASR-HRA implant by measurement of serum Co/Cr levels and PROMs remains essential. Cite this article: Bone Joint J 2023;105-B(7):775–782

Aims. The primary aim of this study was to compare surgical methods (sliding hip screw (SHS) vs intramedullary nailing (IMN)) for trochanteric hip fracture in relation to death within 120 days after surgery and return to independent living. The secondary aim was to assess whether the associations between surgical method and death or ability to return to independent living varied depending on fracture subtype or other patient characteristics. Methods. A total of 27,530 individuals from the Swedish Hip Fracture Register RIKSHÖFT (SHR) aged ≥ 70 years, admitted to hospital between 1 January 2014 and 31 December 2019 with trochanteric hip fracture, were included. Within this cohort, 12,041 individuals lived independently at baseline, had follow-up information in the SHR, and were thus investigated for return to independent living. Death within 120 days after surgery was analyzed using Cox regression with SHS as reference and adjusted for age and fracture type. Return to independent living was analyzed using logistic regression adjusted for age and fracture type. Analyses were repeated after stratification by fracture type, age, and sex. Results. Overall, 2,171 patients (18%) who were operated with SHS and 2,704 patients (18%) who were operated with IMN died within 120 days after surgery. Adjusted Cox regression revealed no difference in death within 120 days for the whole group (hazard ratio 0.97 (95% CI 0.91 to 1.03)), nor after stratification by fracture type. In total, 3,714 (66%) patients who were operated with SHS and 4,147 (64%) patients who were operated with IMN had returned to independent living at follow-up. There was no significant difference in return to independent living for the whole group (odds ratio 0.95 (95% CI 0.87 to 1.03)), nor after stratification by fracture type. Conclusion. No overall difference was observed in death within 120 days or return to independent living following surgery for trochanteric hip fracture, depending on surgical method (SHS vs IMN) in this recent Swedish cohort, but there was a suggested benefit for SHS in subgroups of patients. Cite this article: Bone Jt Open 2024;5(10):843–850

Aims. The aims of this study were to evaluate the incidence of reoperation (all cause and specifically for periprosthetic femoral fracture (PFF)) and mortality, and associated risk factors, following a hemiarthroplasty incorporating a cemented collarless polished taper slip stem (PTS) for management of an intracapsular hip fracture. Methods. This retrospective study included hip fracture patients aged 50 years and older treated with Exeter (PTS) bipolar hemiarthroplasty between 2019 and 2022. Patient demographics, place of domicile, fracture type, delirium status, American Society of Anesthesiologists (ASA) grade, length of stay, and mortality were collected. Reoperation and mortality were recorded up to a median follow-up of 29.5 months (interquartile range 12 to 51.4). Cox regression was performed to evaluate independent risk factors associated with reoperation and mortality. Results. The cohort consisted of 1,619 patients with a mean age of 82.2 years (50 to 104), of whom 1,100 (67.9%) were female. In total, 29 patients (1.8%) underwent a reoperation; 12 patients (0.7%) sustained a PFF during the observation period (United Classification System (UCS)-A n = 2; UCS-B n = 5; UCS-C n = 5), of whom ten underwent surgical management. Perioperative delirium was independently associated with the occurrence of PFF (hazard ratio (HR) 5.92; p = 0.013) and surgery for UCS-B PFF (HR 21.7; p = 0.022). Neither all-cause reoperation nor PFF-related surgery was independently associated with mortality (HR 0.66; p = 0.217 and HR 0.38; p = 0.170, respectively). Perioperative delirium, male sex, older age, higher ASA grade, and pre-fracture residential status were independently associated with increased mortality risk following hemiarthroplasty (p < 0.001). Conclusion. The cumulative incidence of PFF at four years was 1.1% in elderly patients following cemented PTS hemiarthroplasty for a hip fracture. Perioperative delirium was independently associated with a PFF. However, reoperation for PPF was not independently associated with patient mortality after adjusting for patient-specific factors. Cite this article: Bone Jt Open 2024;5(4):269–276

Aims. This study aimed to determine whether lateral femoral wall thickness (LWT) < 20.5 mm was associated with increased revision risk of intertrochanteric fracture (ITF) of the hip following sliding hip screw (SHS) fixation when the medial calcar was intact. Additionally, the study assessed the association between LWT and patient mortality. Methods. This retrospective study included ITF patients aged 50 years and over treated with SHS fixation between 2019 and 2021 at a major trauma centre. Demographic information, fracture type, delirium status, American Society of Anesthesiologists grade, and length of stay were collected. LWT and tip apex distance were measured. Revision surgery and mortality were recorded at a mean follow-up of 19.5 months (1.6 to 48). Cox regression was performed to evaluate independent risk factors associated with revision surgery and mortality. Results. The cohort consisted of 890 patients with a mean age of 82 years (SD 10.2). Mean LWT was 27.0 mm (SD 8.6), and there were 213 patients (23.9%) with LWT < 20.5 mm. Overall, 20 patients (2.2%) underwent a revision surgery following SHS fixation. Adjusting for covariates, LWT < 20.5 mm was not independently associated with an increased revision or mortality risk. However, factors that were significantly more prevalent in LWT < 20.5 mm group, which included residence in care home (hazard ratio (HR) 1.84; p < 0.001) or hospital (HR 1.65; p = 0.005), and delirium (HR 1.32; p = 0.026), were independently associated with an increased mortality risk. The only independent factor associated with increased risk of revision was older age (HR 1.07; p = 0.030). Conclusion. LWT was not associated with risk of revision surgery in patients with an ITF fixed with a SHS when the calcar was intact, after adjusting for the independent effect of age. Although LWT < 20.5 mm was not an independent risk factor for mortality, patients with LWT < 20.5 mm were more likely to be from care home or hospital and have delirium on admission, which were associated with a higher mortality rate. Cite this article: Bone Jt Open 2024;5(2):123–131

Aims. Although there are various pelvic osteotomies for acetabular dysplasia of the hip, shelf operations offer effective and minimally invasive osteotomy. Our study aimed to assess outcomes following modified Spitzy shelf acetabuloplasty. Methods. Between November 2000 and December 2016, we retrospectively evaluated 144 consecutive hip procedures in 122 patients a minimum of five years after undergoing modified Spitzy shelf acetabuloplasty for acetabular dysplasia including osteoarthritis (OA). Our follow-up rate was 92%. The mean age at time of surgery was 37 years (13 to 58), with a mean follow-up of 11 years (5 to 21). Advanced OA (Tönnis grade ≥ 2) was present preoperatively in 16 hips (11%). The preoperative lateral centre-edge angle ranged from -28° to 25°. Survival was determined by Kaplan-Meier analysis, using conversions to total hip arthroplasty as the endpoint. Risk factors for joint space narrowing less than 2 mm were analyzed using a Cox proportional hazards model. Results. The mean Merle d'Aubigné clinical score improved from 11.6 points (6 to 17) preoperatively to 15.9 points (12 to 18) at the last follow-up. The survival rates were 95% (95% confidence interval (CI) 91 to 99) and 86% (95% CI 50 to 97) at ten and 15 years. Multivariate Cox regression identified three factors associated with radiological OA progression: age (hazard ratio (HR) 2.85, 95% CI 1.05 to 7.76; p = 0.0398), preoperative joint space (HR 2.41, 95% CI 1.35 to 4.29; p = 0.0029), and preoperative OA (HR 8.34, 95% CI 0.94 to 73.77; p = 0.0466). Conclusion. Modified Spitzy shelf acetabuloplasty is an effective joint-preserving surgery with a wide range of potential indications. Cite this article: Bone Jt Open 2023;4(12):932–941

Aims. This work aimed at answering the following research questions: 1) What is the rate of mechanical complications, nonunion and infection for head/neck femoral fractures, intertrochanteric fractures, and subtrochanteric fractures in the elderly USA population? and 2) Which factors influence adverse outcomes?. Methods. Proximal femoral fractures occurred between 1 January 2009 and 31 December 2019 were identified from the Medicare Physician Service Records Data Base. The Kaplan-Meier method with Fine and Gray sub-distribution adaptation was used to determine rates for nonunion, infection, and mechanical complications. Semiparametric Cox regression model was applied incorporating 23 measures as covariates to identify risk factors. Results. Union failure occured in 0.89% (95% confidence interval (CI) 0.83 to 0.95) after head/neck fracturs, in 0.92% (95% CI 0.84 to 1.01) after intertrochanteric fracture and in 1.99% (95% CI 1.69 to 2.33) after subtrochanteric fractures within 24 months. A fracture-related infection was more likely to occur after subtrochanteric fractures than after head/neck fractures (1.64% vs 1.59%, hazard ratio (HR) 1.01 (95% CI 0.87 to 1.17); p < 0.001) as well as after intertrochanteric fractures (1.64% vs 1.13%, HR 1.31 (95% CI 1.12 to 1.52); p < 0.001). Anticoagulant use, cerebrovascular disease, a concomitant fracture, diabetes mellitus, hypertension, obesity, open fracture, and rheumatoid disease was identified as risk factors. Mechanical complications after 24 months were most common after head/neck fractures with 3.52% (95% CI 3.41 to 3.64; currently at risk: 48,282). Conclusion. The determination of complication rates for each fracture type can be useful for informed patient-clinician communication. Risk factors for complications could be identified for distinct proximal femur fractures in elderly patients, which are accessible for therapeutical treatment in the management. Cite this article: Bone Jt Open 2023;4(10):801–807

The aims were to assess whether vitamin D deficiency influenced mortality risk for patients presenting with a hip fracture. A retrospective study was undertaken including all patients aged over 50 years that were admitted with a hip fracture to a single centre during a 24-month period. Serum vitamin D levels were assessed. Patient demographics and perioperative variables and mortality were collected. Cox regression analysis (adjusting for confounding) was utilised to determine the independent association between serum vitamin D level and patient mortality. The cohort consisted of 2075 patients with a mean age of 80.7 years and 1471 (70.9%) were female. 1510 (72.8%) patients had a serum vitamin D level taken, of which 876 (58.0%) were deficient (50nmol/l). The median follow up was 417 (IQR 242 to 651) days. During follow up there were 464 (30.7%) deaths. Survival at 1 year was significantly (p=0.003) lower for patients who were vitamin D deficient (71.7%, 95% confidence intervals (CI) 68.6 to 74.9) compared to those who were not (79.0%, 95% CI 75.9 to 82.3). Vitamin D deficiency was also independently associated with an increased mortality risk at 2-years (HR 1.25, 95% CI 1.03 to 1.53, p=0.025), but not at 1-year (p=0.057). Hip fracture patients with vitamin D deficiency had an increased mortality risk. This risk was independent of confounders at 2 years. The role of measuring vitamin D levels in these patients is unclear. Improved public health policy about vitamin D may be required to reduce deficiency in this patient population

Subtrochanteric femoral fractures are a subset of hip fractures generally treated with cephalomedullary nail fixation\[1\]. Single lag screw devices are most commonly-used, but integrated dual screw constructs have become increasingly popular\[2,3\]. The aim of this study was to compare outcomes of fixation of subtrochanteric femoral fractures using a single lag screw (Gamma3 nail, GN) with a dual screw device (InterTAN nail, IN). The primary outcome was mechanical failure, defined as lag screw cut-out, back-out, nail breakage or peri-implant fracture. Consecutive adult patients (18yrs) with subtrochanteric femoral fracture treated in a single centre were retrospectively identified using electronic records. Patients that underwent surgical fixation using either a long GN (2010–2017) or IN (2017–2022) were included. Medical records and radiographs were reviewed to identify complications of fixation. Cox regression analysis was used to determine the risk of mechanical failure and secondary outcomes by implant design. Multivariable regression models were used to identify predictors of mechanical failure. The study included 622 patients, 354 in the GN group (median age 82yrs, 72% female) and 268 in the IN group (median age 82yrs, 69% female). The risk of any mechanical failure was increased two-fold in the GN group (HR 2.44 \[95%CI 1.13 to 5.26\]; _p=0.024_). Mechanical failure comprising screw cut-out (_p=0.032_), back-out (_p=0.032_) and nail breakage (_p=0.26_) was only observed in the GN group. Technical predictors of failure included varus >5° for cut-out (OR 19.98 \[2.06 to 193.88\]; _p=0.01_), TAD;25mm for back-out (8.96 \[1.36 to 58.86\]; p=0.022) and shortening 1cm for peri-implant fracture (7.81 \[2.92 to 20.91\]; _p=<0.001_). Our results demonstrate that an intercalated screw construct is associated with a lower risk of mechanical failure compared with the a single lag screw device. Intercalated screw designs may reduce the risk of mechanical complications for patients with subtrochanteric femoral fractures

Implant fracture of modular revision stems is a major complication after total hip arthroplasty revision (rTHA). Studies looking at specific modular designs report fracture rates of 0.3% to 0.66% whereas fractures of monobloc designs are only reported anecdotally. It is unclear whether the overall re-revision rate of modular designs is higher and if, whether stem fractures or other revision reasons are responsible for this elevation. All revisions within 5 years after implantation of a revision stems (n. 0. =13,900; n. 5. =2506) were analysed using Cox regression with design (modular: n=17, monobloc: n=27), BMI, Sex and Elixhauser Score as independent variables. One stage and two stage revisions were analysed separately (1-stage: modular n= 7,102; monobloc n= 4,542; 2-stage: 1,551 / 704). The revision volume of the hospitals was also considered (low: <20 revisions, medium: 21–50 revisions, high: >50 revisions). For the 1-stage revisions, the re-revision risk after 4 years was 14,3% [13.2%, 15.5%] for monobloc and 17.4% [16.40%, 18.40%] for modular stems (p< 0.001). Stem fracture was the reason for re-revision in 2.4% of the modular (fracture rate 0.42%) and 0.6% of the monobloc revisions. The difference in re-revision rates between the designs was mainly due to differences in dislocation and stem loosening. For the 2-stage revisions, the revision risks for either design were similar (21.7% [18,5%, 25.4%] vs. 23.0% [20.8%, 25.4%]; p=0.05). Patient characteristics influenced the comparison between the two designs in the 1-stage group but very little in the 2-stage group. Modular revision stem fractures only contribute very minor to re-revision risk. In 2-stage revisions, no difference in overall re-revision rates between designs was observed. This might indicate that the differences observed for 1-stage procedures are due to differences between the patient cohorts, not reflected by the parameters available or surgeon choice

The Norwegian Arthroplasty Register (NAR) started collecting data on total hip arthroplasty (THA) in 1987. Very long-term results of implants for THA are scarce. We aimed to show long-term results for the three most used femoral stems, operated from 1987. We included the uncemented Corail femoral stem (n=66,309) and the cemented Exeter stem (n=35,050) both of which are currently in frequent use. In addition, we included the Charnley stem (n=32,578, in use until 2014). To ensure comparable conditions, stems fixated with low viscosity cement and stems revised due to infections were excluded. Differences in risk of revision (all reasons and stem revisions) were assessed with Kaplan-Meier and Cox regression analyses with adjustment for possible confounding from age, sex and diagnosis (OA, other). Stem revision was defined as a revision caused by loosening of the stem, dislocation, osteolysis in the femur, or periprosthetic femur fracture, and in which the femoral component was removed or exchanged. The median and max follow-up for Corail, Exeter and Charnley were 6.3 (33.1), 8.0 (34.2) and 13.1 (34.3) respectively. Thirty years survival estimates for Corail, Exeter and Charnley stems were 88.6% (CI:85.8–90.9%), 86.7% (83.7–89.2%) and 87.1% (85.4–88.5%) respectively with stem revision as endpoint, and 56.1% (CI:53.1–59.1%), 73.3% (70.5–76.1%) and 80.2% (78.4–82.0%) with all THA revisions as endpoint. Compared to the Corail, the Exeter (HRR=1.3, CI:1.2–1.4) and the Charnley (HRR=1.9, CI:1.7–2.1) had a significant higher risk of stem revision. Women 75 years and older had better results with the cemented stems. Analyses accounting for competing risk from other causes of revision did not alter the findings. The uncemented Corail stem performed well in terms of stem revisions for stem-related revision causes compared to two frequently used cemented stems with very long follow-up. The differences between the three stems were small

Dual-mobility (DM) bearings are effective to mitigate dislocation in revision total hip arthroplasty (THA). However, data on its use for treating dislocation is scarce. Aim of this study was to compare DM bearings, standard bearings and constrained liner (CL) in revision THA for recurrent dislocation and to identify risk factors for re-dislocation. We reviewed 100 consecutive revision THAs performed for dislocation from 2012 and 2019. 45 hips (45%) received a DM construct, while 44 hips (44%) and 11 hips (11%) had a standard bearing and CL, respectively. Rates of re-dislocation, re-revision for dislocation and overall re-revision were compared. Radiographs were assessed for cup positioning, restoration of centre of rotation, leg length and offset. Risk factors for re-dislocation were determined by cox regression analysis. Modified Harris hip scores (mHHS) were calculated. Mean follow-up was 53 months (1 to 103). DM constructs were used more frequently in elderly patients (p=0.011) and hips with abductor deficiency (p< 0.001). The re-dislocation rate was 11.1% for DM bearings compared with 15.9% for standard bearings and 18.2% for CL (p=0.732). Revision-free survival for DM constructs was 83% (95% CI 0.77 – 0.90) compared to 75% (95% CI 0.68 – 0.82) for standard articulations and 71% (95% CI 0.56 – 0.85) for CL (p=0.455). Younger age (HR 0.91; p=0.020), lower comorbidity (HR 0.42; p=0.031), smaller heads (HR 0.80; p=0.041) and cup retention (HR 8.23; p=0.022) were associated with re-dislocation. Radiological analysis did not reveal a relationship between restoration of hip geometry and re-dislocation. mHHS significantly improved from 43.8 points to 65.7 points (p<0.001) with no differences among bearing types. Our findings suggest that DM bearings do not sufficiently prevent dislocation in revision THA for recurrent dislocation. Reconstruction of the abductor complex may play a key role to reduce the burden in these high-risk patients

In 2022, approximately 60% of inserted cups and stems in Sweden utilized cemented fixation. Two predominant brands, Refobacin Bone Cement R and Palacos R+G, both incorporating gentamicin, were employed in over 90% of primary cemented Total Hip Arthroplasties (THAs) between 2012 and 2022. This study investigates whether the choice between these cement types affects the risk of revision. The five most frequently used cemented cups and the three most common stems were studied. Inclusion criteria encompassed hips with non-tumour diagnoses, operated through a direct lateral or posterior incision, featuring a 28–36 mm metal or ceramic head. Outcomes were assessed for cup revisions (n=55,457 Refobacin, 37,210 Palacos), stem revisions (n=51,732 Refobacin, 30,018 Palacos), and all-cemented THAs with either brand (n=45,265 Refobacin, 26,347 Palacos). Kaplan-Meier life tables and hazard ratios (HR) utilizing Cox regression were computed, adjusting for age, sex, diagnosis, implant type, femoral head size, and material. Over a 10-year period, the cumulative percent revision with Refobacin was consistently higher than Palacos in all three analyses (cups: Refobacin 2.4 (2.3–2.5), Palacos 2.1 (2.0–2.2); stems: Refobacin 2.6 (2.5–2.7), Palacos 2.1 (2,0–2,2); all-cemented: Refobacin 3.2 (2.9–3.5), Palacos 2.9 (2.6–3.2)). Both unadjusted and adjusted HR were 13–25% lower with Palacos. In the analysis of all-cemented THAs, the adjusted HR for Palacos was 0.85 (0.76–0.95). Separating revisions into infectious and non-infectious reasons revealed a lower risk of infectious revisions with Palacos in all three analyses (all-cemented: adjusted HR infection 0.66 (0.56–0.78); non-infectious 1.10 (0.94–1.28)). Hips cemented with Refobacin may face an increased risk of infection, potentially due to a smaller release of antibiotics into surrounding tissues. Unaccounted factors like different mixing systems or unknown biases could also influence outcomes, emphasizing the need for further investigation

Aims. To investigate the effect of polyethylene manufacturing characteristics and irradiation dose on the survival of cemented and reverse hybrid total hip arthroplasties (THAs). Methods. In this registry study, data from the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man (NJR) were linked with manufacturing data supplied by manufacturers. The primary endpoint was revision of any component. Cox proportional hazard regression was a primary analytic approach adjusting for competing risk of death, patient characteristics, head composition, and stem fixation. Results. A total of 290,770 primary THAs were successfully linked with manufacturing characteristics. Overall 4,708 revisions were analyzed, 1,260 of which were due to aseptic loosening. Total radiation dose was identified as a risk factor and included in the Cox model. For statistical modelling of aseptic loosening, THAs were grouped into three categories: G1 (no radiation); G2 ( > 0 to < 5 Mrad); and G3 ( ≥ 5 Mrad). G1 had the worst survivorship. The Cox regression hazard ratio for revision due to aseptic loosening for G2 was 0.7 (95% confidence interval (CI) 0.58 to 0.83), and for G3 0.4 (95% CI 0.30 to 0.53). Male sex and uncemented stem fixation were associated with higher risk of revision and ceramic heads with lower risk. Conclusion. Polyethylene irradiation was associated with reduced risk of revision for aseptic loosening. Radiation doses of ≥ 5 Mrad were associated with a further reduction in risk. Cite this article: Bone Joint Res 2020;9(9):563–571

Aims. The aim of this study was to estimate time to arthroplasty among patients with hip and knee osteoarthritis (OA), and to identify factors at enrolment to first-line intervention that are prognostic for progression to surgery. Methods. In this longitudinal register-based observational study, we identified 72,069 patients with hip and knee OA in the Better Management of Patients with Osteoarthritis Register (BOA), who were referred for first-line OA intervention, between May 2008 and December 2016. Patients were followed until the first primary arthroplasty surgery before 31 December 2016, stratified into a hip and a knee OA cohort. Data were analyzed with Kaplan-Meier and multivariable-adjusted Cox regression. Results. At five years, Kaplan-Meier estimates showed that 46% (95% confidence interval (CI) 44.6 to 46.9) of those with hip OA, and 20% (95% CI 19.7 to 21.0) of those with knee OA, had progressed to arthroplasty. The strongest prognostic factors were desire for surgery (hazard ratio (HR) hip 3.12 (95% CI 2.95 to 3.31), HR knee 2.72 (95% CI 2.55 to 2.90)), walking difficulties (HR hip 2.20 (95% CI 1.97 to 2.46), HR knee 1.95 (95% CI 1.73 to 2.20)), and frequent pain (HR hip 1.56 (95% CI 1.40 to 1.73), HR knee 1.77 (95% CI 1.58 to 2.00)). In hip OA, the probability of progression to surgery was lower among those with comorbidities (e.g. ≥ four conditions; HR 0.64 (95% CI 0.59 to 0.69)), with no detectable effects in the knee OA cohort. Instead, being overweight or obese increased the probability of OA progress in the knee cohort (HR 1.25 (95% CI 1.15 to 1.37)), but not among those with hip OA. Conclusion. Patients with hip OA progressed faster and to a greater extent to arthroplasty than patients with knee OA. Progression was strongly influenced by patients’ desire for surgery and by factors related to severity of OA symptoms, but factors not directly related to OA symptoms are also of importance. However, a large proportion of patients with OA do not seem to require surgery within five years, especially among those with knee OA. Cite this article: Bone Joint J 2022;104-B(7):792–800

We determined the impact of deprivation and frailty at the time of diagnosis of hip osteoarthritis (OA) on the likelihood of receiving total hip arthroplasty (THA). We used routinely collected primary care data (Clinical Practice Research Datalink) linked to Hospital Episode Statistics. Frailty was assessed at the time of hip OA diagnosis using a validated frailty index based on coded data in the primary care record and categorised as fit, mild, moderate, and severe frailty. The association between quintile of index of multiple deprivation (IMD), frailty category and likelihood of receiving THA was assessed in separate Cox regression models, adjusted for year of OA diagnosis, age, and sex. 104,672 individuals with hip OA contributed. Compared to those in the first quintile of IMD (least deprived), those in the fourth and fifth quintile of IMD (most deprived), respectively, were less likely to receive THA, hazard ratio (HR) (95% CI), 0.92 (0.89, 0.95) and 0.80 (0.77, 0.83). Increasing frailty at OA diagnosis was associated with reduced likelihood of receiving THA. Compared to fit individuals, the HR (95% CI) for receiving THA among those with: mild frailty was 0.80 (0.78, 0.82); moderate frailty was 0.60 (0.58, 0.62); and severe frailty was 0.42 (0.39, 0.45). Increasing deprivation was associated with increasing frailty at the time of hip OA diagnosis, independent of age, sex, and year of OA diagnosis. However, those in the two most deprived quintiles were still less likely to receive THA after additionally adjusting for frailty category. Greater deprivation and greater frailty were associated with lower likelihood of receiving THA among people with hip osteoarthritis. Greater frailty among those most deprived did not explain the reduced likelihood of receiving THA among those most deprived

We determined the association between frailty and 30-day mortality following total hip arthroplasty (THA) and the impact of THA on 30-day mortality compared to a control population. We used primary care data (Clinical Practice Research Datalink), linked secondary care data (Hospital Episode Statistics) and Office for National Statistics mortality data. Frailty was assessed using a validated frailty index based on coded data in the primary care record and categorised as fit, mild, moderate, and severe frailty. The association between frailty and 30-day mortality following THA due to osteoarthritis was assessed using Cox regression, adjusted for year of birth, sex, quintile of index of multiple deprivation and year of surgery. Mortality following THA was also compared to a control population who had osteoarthritis but no previous THA, matched on year of birth, sex, and quintile of index of multiple deprivation. 103,563 cases who had a THA and their matched controls contributed data. Among those who had THA, compared to fit participants, 30-day mortality increased with increasing frailty; adjusted hazard ratio (HR) (95% CI) among mild frailty, 0.87 (0.66, 1.15); moderate frailty 1.73 (1.26, 2.38); and severe frailty, 2.85 (1.84, 4.39). Compared to fit controls who did not have surgery, 30-day mortality was higher among fit people who had THA, adjusted HR 1.60 (1.15, 2.21). There was, however, no statistically significant difference in 30-day mortality among cases with mild, moderate and severe frailty compared to controls in the same frailty category. Among people who had THA, 30-day mortality increased with increasing frailty. While 30-day mortality was increased among fit individuals who had THA compared to fit controls who did not have surgery, there did not appear to be increased mortality among individuals with mild, moderate or severe frailty compared to controls in the same frailty category. A healthy surgery (selection) effect may have impacted on the comparison of mortality among cases and controls

Hip fracture principally affects the frailest in society, many of whom are care dependent, and are disproportionately at risk of contracting COVID-19. We examined the impact of COVID-19 infection on hip fracture mortality in England. We conducted a cohort study of patients with hip fracture recorded in the National Hip Fracture Database between 1st February 2019 and 31st October 2020, in England. Data were linked to Hospital Episode Statistics to quantify patient characteristics and comorbidities, Office for National Statistics mortality data, and Public Health England's SARS-CoV-2 testing results. Multivariable Cox regression examined determinants of 90-day mortality. Excess mortality attributable to COVID-19 was quantified using Quasi-Poisson models. Analysis of 102,900 hip fractures (42,630 occurring during the pandemic) revealed that amongst those with COVID-19 infection at presentation (n=1,120) there was a doubling of 90-day mortality; hazard ratio (HR) 2.05 (95%CI 1.86–2.26), while for infections arising between 8–30 days after presentation (n=1,644) the figure was even higher at 2.52 (2.32–2.73). Malnutrition [1.44 (1.19–1.75)] and non-operative treatment [2.89 (2.16–3.86)] were the only modifiable risk factors for death in COVID-19 positive patients. Patients with previous COVID-19 initially had better survival compared to those who contracted COVID-19 around the time of their hip fracture; however, survival rapidly declined and by 365 days the combination of hip fracture and COVID-19 infection was associated with a 50% mortality rate. Between 1st January and 30th June 2020, 1,273 (99.7%CI 1,077–1,465) excess deaths occurred within 90 days of hip fracture, representing an excess mortality of 23% (20%–26%), with most deaths occurring within 30 days. COVID-19 infection more than doubled early hip fracture mortality; the first 30-days after injury were most critical, suggesting that targeted interventions in this period may have most benefit in improving survival

Young patients are at increased risk of revision after primary THA (THA). The bearing surface may be of importance for the longevity of the joint. We aimed to compare the risk of revision of primary stemmed cementless THA with MoM and CoC with metal-on-highly-crosslinked-polyethylene (MoXLP) bearings in patients between 20–54 years. From NARA, we included 2,153 MoM, 4,120 CoC and 10,329 MoXLP THA operated between 1995 and 2017. Kaplan-Meier estimator was used for calculation of THA survivorship and Cox regression to estimate the hazard ratio (HR) of revision (95% CI) due to any and specific causes. MoXLP was reference. The median follow-up was 10.3 years for MoM, 6.6 years for CoC and 4.8 years for MoXLP. 15 years postoperatively the Kaplan-Meier survival estimates were 80% (78–83%) for MoM, 92% (91–93%) for CoC and 94% (93–95%) for MoXLP. The 0–2, 2–7 and 7–15 years adjusted HRs of revision by any cause were 1.4 (0.9–2.4), 3.2 (2.1–5.1) and 3.9 (1.9–7.9) for MoM and 1.1 (0.8–1.4), 1.0 (0.7–1.3) and 2.5 (1.3–4.8) for CoC bearings. After 7–15 years follow-up, the unadjusted HR of revision due to aseptic loosening was 5.4 (1.2–24) for MoM and 4.2 (0.9–20) for CoC THA. MoM and CoC had a 7–15 year adjusted HR of revision due to ‘other’ causes of 4.8 (1.6–14) and 2.1 (0.8–5.8). MoXLP bearings were associated with better survival than MoM and CoC bearings, mainly because of lower risk of revision due to aseptic loosening and ‘other’ causes

To design osteoarthritis (OA) care based on prognosis, we need to identify individuals who are most likely of disease progression. We estimated survival time of the native hip and knee joint and evaluated what patient-related and OA disease-related factors associated with progression to joint replacement surgery. We included 72,069 patients referred to first-line OA intervention (patient education and exercise) during 2008 and 2016 and registered in the Swedish quality register Better Management of Patients with Osteoarthritis (BOA). Kaplan–Meier survival analyses were used to estimate joint survival time. Hazard ratios (HR) with 95% confidence interval [CI] were calculated using multiple Cox regression. The 5-year survival time of the native joint was 56% for hip OA and 80% for knee OA. Disease-related factors were more strongly associated with progression to joint replacement (e.g. willingness for surgery HR; hip 2.9 [95% CI, 2.7–3.1], knee 2.7 [2.6–2.9] and walking difficulties (HR; hip 2.2 [2.0–2.5], knee 1.9 [1.7–2.2]), than patient-related factors such socioeconomic factors (e.g. highest income quartile HR; hip 1.3 [1.2–1.3], knee 1.3 [1.2–1.4]) and comorbidities (e.g. ≥6 conditions HR; hip: 0.7 [0.6–0.7], knee; 1.1 [1.0–1.2]). Patients with hip OA were more likely to undergo surgery and at an earlier time compared with those with knee OA. Progression was strongly influenced by factors associated with the OA disease, but other patient-related factors are important. However, a large proportion of patients with OA do not seem to require surgery, especially among those with knee OA