Aims. This study aimed to describe preoperative waiting times for surgery in hip fracture patients in Norway, and analyze factors affecting waiting time and potential negative consequences of prolonged waiting time. Methods. Overall, 37,708 hip fractures in the Norwegian Hip Fracture Register from January 2014 to December 2018 were linked with data in the Norwegian Patient Registry. Hospitals treating hip fractures were characterized according to their hip fracture care. Waiting time (hours from admission to start of surgery), surgery within regular working hours, and surgery on the day of or on the day after admission, i.e. ‘expedited surgery’ were estimated. Results. Mean waiting time was 22.6 hours (SD 20.7); 36,652 patients (97.2%) waited less than three days (< 72 hours), and 27,527 of the patients (73%) were operated within regular working hours (08:00 to 16:00). Expedited surgery was given to 31,675 of patients (84%), and of these, 19,985 (53%) were treated during regular working hours. Patients classified as American Society of Anesthesiologists (ASA) classes 4 and 5 were more likely to have surgery within regular working hours (odds ratio (OR) 1.59; p < 0.001), and less likely to receive expedited surgery than ASA 1 patients (OR 0.29; p < 0.001). Low-volume hospitals treated a larger proportion of patients during regular working hours than high volume hospitals (OR 1.26; p < 0.001). High-volume hospitals had less expedited surgery and significantly longer waiting times than low and intermediate-low volume hospitals. Higher ASA classes and Charlson Comorbidity Index increased waiting time. Patients not receiving expedited surgery had higher 30-day and one-year mortality rates (OR 1.19; p < 0.001) and OR 1.13; p < 0.001), respectively. Conclusion. There is inequality in waiting time for hip fracture treatment in Norway. Variations in waiting time from admission to hip fracture surgery depended on both patient and hospital factors. Not receiving expedited surgery was associated with increased 30-day and one-year mortality rates. Cite this article: Bone Jt Open 2021;2(9):710–720

Aims. Hip fracture patients have high morbidity and mortality. Patient-reported outcome measures (PROMs) assess the quality of care of patients with hip fracture, including those with chronic cognitive impairment (CCI). Our aim was to compare PROMs from hip fracture patients with and without CCI, using the Norwegian Hip Fracture Register (NHFR). Methods. PROM questionnaires at four months (n = 34,675) and 12 months (n = 24,510) after a hip fracture reported from 2005 to 2018 were analyzed. Pre-injury score was reported in the four-month questionnaire. The questionnaires included the EuroQol five-dimension three-level (EQ-5D-3L) questionnaire, and information about who completed the questionnaire. Results. Of the 34,675 included patients, 5,643 (16%) had CCI. Patients with CCI were older (85 years vs 81 years) (p < 0.001), and had a higher American Society of Anesthesiologists (ASA) classification compared to patients without CCI. CCI was unrelated to fracture type and treatment method. EQ-5D index scores were lower in patients with CCI after four months (0.37 vs 0.60; p < 0.001) and 12 months (0.39 vs 0.64; p < 0.001). Patients with CCI had lower scores for all dimensions of the EQ-5D-3L pre-fracture and at four and 12 months. Conclusion. Patients with CCI reported lower health-related quality of life pre-fracture, at four and 12 months after the hip fracture. PROM data from hip fracture patients with CCI are valuable in the assessment of treatment. Patients with CCI should be included in future studies. Cite this article: Bone Jt Open 2021;2(7):454–465

Aims. The aim of this study was to describe variation in hip fracture treatment in Norway expressed as adherence to international and national evidence-based treatment guidelines, to study factors influencing deviation from guidelines, and to analyze consequences of non-adherence. Methods. International and national guidelines were identified and treatment recommendations extracted. All 43 hospitals routinely treating hip fractures in Norway were characterized. From the Norwegian Hip Fracture Register (NHFR), hip fracture patients aged > 65 years and operated in the period January 2014 to December 2018 for fractures with conclusive treatment guidelines were included (n = 29,613: femoral neck fractures (n = 21,325), stable trochanteric fractures (n = 5,546), inter- and subtrochanteric fractures (n = 2,742)). Adherence to treatment recommendations and a composite indicator of best practice were analyzed. Patient survival and reoperations were evaluated for each recommendation. Results. Median age of the patients was 84 (IQR 77 to 89) years and 69% (20,427/29,613) were women. Overall, 79% (23,390/29,613) were treated within 48 hours, and 80% (23,635/29,613) by a surgeon with more than three years’ experience. Adherence to guidelines varied substantially but was markedly better in 2018 than in 2014. Having a dedicated hip fracture unit (OR 1.06, 95%CI 1.01 to 1.11) and a hospital hip fracture programme (OR 1.16, 95% CI 1.06 to 1.27) increased the probability of treatment according to best practice. Surgery after 48 hours increased one-year mortality significantly (OR 1.13, 95% CI 1.05 to 1.22; p = 0.001). Alternative treatment to arthroplasty for displaced femoral neck fractures (FNFs) increased mortality after 30 days (OR 1.29, 95% CI 1.03 to 1.62)) and one year (OR 1.45, 95% CI 1.22 to 1.72), and also increased the number of reoperations (OR 4.61, 95% CI 3.73 to 5.71). An uncemented stem increased the risk of reoperation significantly (OR 1.23, 95% CI 1.02 to 1.48; p = 0.030). Conclusion. Our study demonstrates a substantial variation between hospitals in adherence to evidence-based guidelines for treatment of hip fractures in Norway. Non-adherence can be ascribed to in-hospital factors. Poor adherence has significant negative consequences for patients in the form of increased mortality rates at 30 and 365 days post-treatment and in reoperation rates. Cite this article: Bone Joint Open 2020;1-10:644–653

Aims. The primary aim was to assess the independent influence of coronavirus disease (COVID-19) on 30-day mortality for patients with a hip fracture. The secondary aims were to determine whether: 1) there were clinical predictors of COVID-19 status; and 2) whether social lockdown influenced the incidence and epidemiology of hip fractures. Methods. A national multicentre retrospective study was conducted of all patients presenting to six trauma centres or units with a hip fracture over a 46-day period (23 days pre- and 23 days post-lockdown). Patient demographics, type of residence, place of injury, presentation blood tests, Nottingham Hip Fracture Score, time to surgery, operation, American Society of Anesthesiologists (ASA) grade, anaesthetic, length of stay, COVID-19 status, and 30-day mortality were recorded. Results. Of 317 patients with acute hip fracture, 27 (8.5%) had a positive COVID-19 test. Only seven (26%) had suggestive symptoms on admission. COVID-19-positive patients had a significantly lower 30-day survival compared to those without COVID-19 (64.5%, 95% confidence interval (CI) 45.7 to 83.3 vs 91.7%, 95% CI 88.2 to 94.8; p < 0.001). COVID-19 was independently associated with increased 30-day mortality risk adjusting for: 1) age, sex, type of residence (hazard ratio (HR) 2.93; p = 0.008); 2) Nottingham Hip Fracture Score (HR 3.52; p = 0.001); and 3) ASA (HR 3.45; p = 0.004). Presentation platelet count predicted subsequent COVID-19 status; a value of < 217 × 10. 9. /l was associated with 68% area under the curve (95% CI 58 to 77; p = 0.002) and a sensitivity and specificity of 63%. A similar number of patients presented with hip fracture in the 23 days pre-lockdown (n = 160) and 23 days post-lockdown (n = 157) with no significant (all p ≥ 0.130) difference in patient demographics, residence, place of injury, Nottingham Hip Fracture Score, time to surgery, ASA, or management. Conclusion. COVID-19 was independently associated with an increased 30-day mortality rate for patients with a hip fracture. Notably, most patients with hip fracture and COVID-19 lacked suggestive symptoms at presentation. Platelet count was an indicator of risk of COVID-19 infection. These findings have implications for the management of hip fractures, in particular the need for COVID-19 testing. Cite this article: Bone Joint J 2020;102-B(9):1219–1228

Aims. This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads. Methods. In all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity. Half of each head size group were then cycled with simulated gait and the other half with gait compression only. Damage was measured by area and maximum linear wear depth. Results. Overall, 36 mm heads had lower corrosion onset load (p = 0.009) and change in open circuit potential (OCP) during simulated gait with (p = 0.006) and without joint movement (p = 0.004). Discontinuing gait’s joint movement decreased corrosion currents (p = 0.042); however, wear testing showed no significant effect of joint movement on taper damage. In addition, 36 mm heads had greater corrosion area (p = 0.050), but no significant difference was found for maximum linear wear depth (p = 0.155). Conclusion. Larger heads are more susceptible to taper corrosion; however, not due to frictional torque as hypothesized. An alternative hypothesis of taper flexural rigidity differential is proposed. Further studies are necessary to investigate the clinical significance and underlying mechanism of this finding. Cite this article: Bone Jt Open 2021;2(11):1004–1016

Aims. Type 2 diabetes mellitus (T2DM) impairs bone strength and is a significant risk factor for hip fracture, yet currently there is no reliable tool to assess this risk. Most risk stratification methods rely on bone mineral density, which is not impaired by diabetes, rendering current tests ineffective. CT-based finite element analysis (CTFEA) calculates the mechanical response of bone to load and uses the yield strain, which is reduced in T2DM patients, to measure bone strength. The purpose of this feasibility study was to examine whether CTFEA could be used to assess the hip fracture risk for T2DM patients. Methods. A retrospective cohort study was undertaken using autonomous CTFEA performed on existing abdominal or pelvic CT data comparing two groups of T2DM patients: a study group of 27 patients who had sustained a hip fracture within the year following the CT scan and a control group of 24 patients who did not have a hip fracture within one year. The main outcome of the CTFEA is a novel measure of hip bone strength termed the Hip Strength Score (HSS). Results. The HSS was significantly lower in the study group (1.76 (SD 0.46)) than in the control group (2.31 (SD 0.74); p = 0.002). A multivariate model showed the odds of having a hip fracture were 17 times greater in patients who had an HSS ≤ 2.2. The CTFEA has a sensitivity of 89%, a specificity of 76%, and an area under the curve of 0.90. Conclusion. This preliminary study demonstrates the feasibility of using a CTFEA-based bone strength parameter to assess hip fracture risk in a population of T2DM patients. Cite this article: Bone Joint J 2021;103-B(9):1497–1504

Aims. The aim of this study was to perform a cross-cultural adaptation of Oxford Hip Score (OHS) to Indonesian, and to evaluate its psychometric properties. Methods. We performed a cross-cultural adaptation of Oxford Hip Score into Indonesian language (OHS-ID) and determined its internal consistency, test-retest reliability, measurement error, floor-ceiling effect, responsiveness, and construct validity by hypotheses testing of its correlation with Harris Hip Score (HHS), vsual analogue scale (VAS), and Short Form-36 (SF-36). Adults (> 17 years old) with chronic hip pain (osteoarthritis or osteonecrosis) were included. Results. A total of 125 patients were included, including 50 total hip arthroplasty (THA) patients with six months follow-up. The OHS questionnaire was translated into Indonesian and showed good internal consistency (Cronbach’s alpha = 0.89) and good reliability (intraclass correlation = 0.98). The standard error of measurement value of 2.11 resulted in minimal detectable change score of 5.8. Ten out of ten (100%) a priori hypotheses were met, confirming the construct validity. A strong correlation was found with two subscales of SF-36 (pain and physical function), HHS (0.94), and VAS (-0.83). OHS-ID also showed good responsiveness for post-THA series. Floor and ceiling effect was not found. Conclusion. The Indonesian version of OHS showed similar reliability and validity with the original OHS. This questionnaire will be suitable to assess chronic hip pain in Indonesian-speaking patients. Cite this article: Bone Jt Open 2021;2(9):765–772

Aims. The aim of this study was to investigate if there are differences in outcome between sliding hip screws (SHSs) and intramedullary nails (IMNs) with regard to fracture stability. Methods. We assessed data from 17,341 patients with trochanteric or subtrochanteric fractures treated with SHS or IMN in the Norwegian Hip Fracture Register from 2013 to 2019. Primary outcome measures were reoperations for stable fractures (AO Foundation/Orthopaedic Trauma Association (AO/OTA) type A1) and unstable fractures (AO/OTA type A2, A3, and subtrochanteric fractures). Secondary outcome measures were reoperations for A2, A3, and subtrochanteric fractures individually, one-year mortality, quality of life (EuroQol five-dimension three-level index score), pain (visual analogue scale (VAS)), and satisfaction (VAS) for stable and unstable fractures. Hazard rate ratios (HRRs) for reoperation were calculated using Cox regression analysis with adjustments for age, sex, and American Society of Anesthesiologists score. Results. Reoperation rate was lower after surgery with IMN for unstable fractures one year (HRR 0.82, 95% confidence interval (CI) 0.70 to 0.97; p = 0.022) and three years postoperatively (HRR 0.86, 95% CI 0.74 to 0.99; p = 0.036), compared with SHS. For individual fracture types, no clinically significant differences were found. Lower one-year mortality was found for IMN compared with SHS for stable fractures (HRR 0.87; 95% CI 0.78 to 0.96; p = 0.007), and unstable fractures (HRR 0.91, 95% CI 0.84 to 0.98; p = 0.014). Conclusion. This national register-based study indicates a lower reoperation rate for IMN than SHS for unstable trochanteric and subtrochanteric fractures, but not for stable fractures or individual fracture types. The choice of implant may not be decisive to the outcome of treatment for stable trochanteric fractures in terms of reoperation rate. One-year mortality rate for unstable and stable fractures was lower in patients treated with IMN. Cite this article: Bone Joint J 2022;104-B(2):274–282

Aims

Knee arthroplasty surgery is a highly effective treatment for arthritis and disorders of the knee. There are a wide variety of implant brands and types of knee arthroplasty available to surgeons. As a result of a number of highly publicized failures, arthroplasty surgery is highly regulated in the UK and many other countries through national registries, introduced to monitor implant performance, surgeons, and hospitals. With time, the options available within many brand portfolios have grown, with alternative tibial or femoral components, tibial insert materials, or shapes and patella resurfacings. In this study we have investigated the effect of the expansion of implant brand portfolios and where there may be a lack of transparency around a brand name. We also aimed to establish the potential numbers of compatible implant construct combinations.

Aims. Developmental dysplasia of the hip (DDH) is a complex musculoskeletal disease that occurs mostly in children. This study aimed to investigate the molecular changes in the hip joint capsule of patients with DDH. Methods. High-throughput sequencing was used to identify genes that were differentially expressed in hip joint capsules between healthy controls and DDH patients. Biological assays including cell cycle, viability, apoptosis, immunofluorescence, reverse transcription polymerase chain reaction (RT-PCR), and western blotting were performed to determine the roles of the differentially expressed genes in DDH pathology. Results. More than 1,000 genes were differentially expressed in hip joint capsules between healthy controls and DDH. Both gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that extracellular matrix (ECM) modifications, muscle system processes, and cell proliferation were markedly influenced by the differentially expressed genes. Expression of Collagen Type I Alpha 1 Chain (COL1A1), COL3A1, matrix metalloproteinase-1 (MMP1), MMP3, MMP9, and MMP13 was downregulated in DDH, with the loss of collagen fibres in the joint capsule. Expression of transforming growth factor beta 1 (TGF-β1) was downregulated, while that of TGF-β2, Mothers against decapentaplegic homolog 3 (SMAD3), and WNT11 were upregulated in DDH, and alpha smooth muscle actin (αSMA), a key myofibroblast marker, showed marginal increase. In vitro studies showed that fibroblast proliferation was suppressed in DDH, which was associated with cell cycle arrest in G0/G1 and G2/M phases. Cell cycle regulators including Cyclin B1 (CCNB1), Cyclin E2 (CCNE2), Cyclin A2 (CCNA2), Cyclin-dependent kinase 1 (CDK1), E2F1, cell division cycle 6 (CDC6), and CDC7 were downregulated in DDH. Conclusion. DDH is associated with the loss of collagen fibres and fibroblasts, which may cause loose joint capsule formation. However, the degree of differentiation of fibroblasts to myofibroblasts needs further study. Cite this article: Bone Joint Res 2021;10(9):558–570

Aims. The primary aim was to determine the influence of COVID-19 on 30-day mortality following hip fracture. Secondary aims were to determine predictors of COVID-19 status on presentation and later in the admission; the rate of hospital acquired COVID-19; and the predictive value of negative swabs on admission. Methods. A nationwide multicentre retrospective cohort study was conducted of all patients presenting with a hip fracture to 17 Scottish centres in March and April 2020. Demographics, presentation blood tests, COVID-19 status, Nottingham Hip Fracture Score, management, length of stay, and 30-day mortality were recorded. Results. In all, 78/833 (9.4%) patients were diagnosed with COVID-19. The 30-day survival of patients with COVID-19 was significantly lower than for those without (65.4% vs 91%; p < 0.001). Diagnosis of COVID-19 within seven days of admission (likely community acquired) was independently associated with male sex (odds ratio (OR) 2.34, p = 0.040, confidence interval (CI) 1.04 to 5.25) and symptoms of COVID-19 (OR 15.56, CI 6.61 to 36.60, p < 0.001). Diagnosis of COVID-19 made between seven and 30 days of admission to hospital (likely hospital acquired) was independently associated with male sex (OR 1.73, CI 1.05 to 2.87, p = 0.032), Nottingham Hip Fracture Score ≥ 7 (OR 1.91, CI 1.09 to 3.34, p = 0.024), pulmonary disease (OR 1.68, CI 1.00 to 2.81, p = 0.049), American Society of Anesthesiologists (ASA) grade ≥ 3 (OR 2.37, CI 1.13 to 4.97, p = 0.022), and length of stay ≥ nine days (OR 1.98, CI 1.18 to 3.31, p = 0.009). A total of 38 (58.5%) COVID-19 cases were probably hospital acquired infections. The false-negative rate of a negative swab on admission was 0% in asymptomatic patients and 2.9% in symptomatic patients. Conclusion. COVID-19 was independently associated with a three times increased 30-day mortality rate. Nosocomial transmission may have accounted for approximately half of all cases during the first wave of the pandemic. Identification of risk factors for having COVID-19 on admission or acquiring COVID-19 in hospital may guide pathways for isolating or shielding patients respectively. Length of stay was the only modifiable risk factor, which emphasizes the importance of high-quality and timely care in this patient group. Cite this article: Bone Joint J 2021;103-B(5):888–897

Aims. The COVID-19 pandemic has caused unprecedented disruption to elective orthopaedic services. The primary objective of this study was to examine changes in functional scores in patients awaiting total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA). Secondary objectives were to investigate differences between these groups and identify those in a health state ‘worse than death’ (WTD). Methods. In this prospective cohort study, preoperative Oxford hip and knee scores (OHS/OKS) were recorded for patients added to a waiting list for THA, TKA, or UKA, during the initial eight months of the COVID-19 pandemic, and repeated at 14 months into the pandemic (mean interval nine months (SD 2.84)). EuroQoL five-dimension five-level health questionnaire (EQ-5D-5L) index scores were also calculated at this point in time, with a negative score representing a state WTD. OHS/OKS were analyzed over time and in relation to the EQ-5D-5L. Results. A total of 174 patients (58 THA, 74 TKA, 42 UKA) were eligible, after 27 were excluded (one died, seven underwent surgery, 19 non-responders). The overall mean OHS/OKS deteriorated from 15.43 (SD 6.92), when patients were added to the waiting list, to 11.77 (SD 6.45) during the pandemic (p < 0.001). There were significantly worse EQ-5D-5L index scores in the THA group (p = 0.005), with 22 of these patients (38%) in a health state WTD, than either the TKA group (20 patients; 27% WTD), or the UKA group (nine patients; 21% WTD). A strong positive correlation between the EQ-5D-5L index score and OHS/OKS was observed (r = 0.818; p < 0.001). Receiver operating characteristic analysis revealed that an OHS/OKS lower than nine predicted a health state WTD (88% sensitivity and 73% specificity). Conclusion. OHS/OKS deteriorated significantly among patients awaiting lower limb arthroplasty during the COVID-19 pandemic. Overall, 51 patients were in a health state WTD, representing 29% of our entire cohort, which is considerably worse than existing pre-pandemic data. Cite this article: Bone Jt Open 2023;4(3):138–145

Aims. The aim of this study was to determine whether national standards of best practice are associated with improved health-related quality of life (HRQoL) outcomes in hip fracture patients. Methods. This was a multicentre cohort study conducted in 20 acute UK NHS hospitals treating hip fracture patients. Patients aged ≥ 60 years treated operatively for a hip fracture were eligible for inclusion. Regression models were fitted to each of the “Best Practice Tariff” indicators and overall attainment. The impact of attainment on HRQoL was assessed by quantifying improvement in EuroQol five-dimension five-level questionnaire (EQ-5D-5L) from estimated regression model coefficients. Results. A total of 6,532 patients provided both baseline and four-month EQ-5D-5L, of whom 1,060 participants had died at follow-up. Best practice was achieved in the care of 57% of participants; there was no difference in age, cognitive ability, and mobility at baseline for the overall attainment and non-attainment groups. Attaining at least ‘joint care by surgeon and orthogeriatrician’, ‘delirium assessment’, and ‘falls assessment’ was associated with a large, clinically relevant increase in four months EQ-5D-5L of 0.094 (bootstrapped 95% confidence interval (CI) 0.046 to 0.146). Conclusion. National standards with enhanced remuneration in hip fracture care results in improvement in individual patients’ HRQoL. Cite this article: Bone Joint J 2021;103-B(5):881–887

Aims. Improvements in functional results and long-term survival are variable following conversion of hip fusion to total hip arthroplasty (THA) and complications are high. The aim of the study was to analyze the clinical and functional results in patients who underwent conversion of hip fusion to THA using a consistent technique and uncemented implants. Methods. A total of 39 hip fusion conversions to THA were undertaken in 38 patients by a single surgeon employing a consistent surgical technique and uncemented implants. Parameters assessed included Harris Hip Score (HHS) for function, range of motion (ROM), leg length discrepancy (LLD), satisfaction, and use of walking aid. Radiographs were reviewed for loosening, subsidence, and heterotopic ossification (HO). Postoperative complications and implant survival were assessed. Results. At mean 12.2 years (2 to 24) follow-up, HHS improved from mean 34.2 (20.8 to 60.5) to 75 (53.6 to 94.0; p < 0.001). Mean postoperative ROM was flexion 77° (50° to 95°), abduction 30° (10° to 40°), adduction 20° (5° to 25°), internal rotation 18° (2° to 30°), and external rotation 17° (5° to 30°). LLD improved from mean -3.36 cm (0 to 8) to postoperative mean -1.14 cm (0 to 4; p < 0.001). Postoperatively, 26 patients (68.4%) required the use of a walking aid. Complications included one (2.5%) dislocation, two (5.1%) partial sciatic nerve injuries, one (2.5%) deep periprosthetic joint infection, two instances of (5.1%) acetabular component aseptic loosening, two (5.1%) periprosthetic fractures, and ten instances of HO (40%), of which three (7.7%) were functionally limiting and required excision. Kaplan-Meier Survival was 97.1% (95% confidence interval (CI) 91.4% to 100%) at ten years and 88.2% (95% CI 70.96 to 100) at 15 years with implant revision for aseptic loosening as endpoint and 81.7% (95% CI 70.9% to 98.0%) at ten years and 74.2% (95% CI 55.6 to 92.8) at 15 years follow-up with implant revision for all cause failure as endpoint. Conclusion. The use of an optimal and consistent surgical technique and cementless implants can result in significant functional improvement, low complication rates, long-term implant survival, and high patient satisfaction following conversion of hip fusion to THA. The possibility of requiring a walking aid should be discussed with the patient before surgery. Cite this article: Bone Joint J 2021;103-B(7 Supple B):129–134

Aims. The aim of the HIPGEN consortium is to develop the first cell therapy product for hip fracture patients using PLacental-eXpanded (PLX-PAD) stromal cells. Methods. HIPGEN is a multicentre, multinational, randomized, double-blind, placebo-controlled trial. A total of 240 patients aged 60 to 90 years with low-energy femoral neck fractures (FNF) will be allocated to two arms and receive an intramuscular injection of either 150 × 10. 6. PLX-PAD cells or placebo into the medial gluteal muscle after direct lateral implantation of total or hemi hip arthroplasty. Patients will be followed for two years. The primary endpoint is the Short Physical Performance Battery (SPPB) at week 26. Secondary and exploratory endpoints include morphological parameters (lean body mass), functional parameters (abduction and handgrip strength, symmetry in gait, weightbearing), all-cause mortality rate and patient-reported outcome measures (Lower Limb Measure, EuroQol five-dimension questionnaire). Immunological biomarker and in vitro studies will be performed to analyze the PLX-PAD mechanism of action. A sample size of 240 subjects was calculated providing 88% power for the detection of a 1 SPPB point treatment effect for a two-sided test with an α level of 5%. Conclusion. The HIPGEN study assesses the efficacy, safety, and tolerability of intramuscular PLX-PAD administration for the treatment of muscle injury following arthroplasty for hip fracture. It is the first phase III study to investigate the effect of an allogeneic cell therapy on improved mobilization after hip fracture, an aspect which is in sore need of addressing for the improvement in standard of care treatment for patients with FNF. Cite this article: Bone Jt Open 2022;3(4):340–347

Aims. The aim of this study to compare 30-day survival and recovery of mobility between patients mobilized early (on the day of, or day after surgery for a hip fracture) and patients mobilized late (two days or more after surgery), and to determine whether the presence of dementia influences the association between the timing of mobilization, 30-day survival, and recovery. Methods. Analysis of the National Hip Fracture Database and hospital records for 126,897 patients aged ≥ 60 years who underwent surgery for a hip fracture in England and Wales between 2014 and 2016. Using logistic regression, we adjusted for covariates with a propensity score to estimate the association between the timing of mobilization, survival, and recovery of walking ability. Results. A total of 99,667 patients (79%) mobilized early. Among those mobilized early compared to those mobilized late, the weighted odds ratio of survival was 1.92 (95% confidence interval (CI) 1.80 to 2.05), of recovering outdoor ambulation was 1.25 (95% CI 1.03 to 1.51), and of recovering indoor ambulation was 1.53 (95% CI 1.32 to 1.78) by 30 days. The weighted probabilities of survival at 30 days post-admission were 95.9% (95% CI 95.7% to 96.0%) for those who mobilized early and 92.4% (95% CI 92.0% to 92.8%) for those who mobilized late. The weighted probabilities of regaining the ability to walk outdoors were 9.7% (95% CI 9.2% to 10.2%) and indoors 81.2% (95% CI 80.0% to 82.4%), for those who mobilized early, and 7.9% (95% CI 6.6% to 9.2%) and 73.8% (95% CI 71.3% to 76.2%), respectively, for those who mobilized late. Patients with dementia were less likely to mobilize early despite observed associations with survival and ambulation recovery for those with and without dementia. Conclusion. Early mobilization is associated with survival and recovery for patients (with and without dementia) after hip fracture. Early mobilization should be incorporated as a measured indicator of quality. Reasons for failure to mobilize early should also be recorded to inform quality improvement initiatives. Cite this article: Bone Joint J 2021;103-B(7):1317–1324

Aims. The Patient-Reported Outcomes Measurement Information System (PROMIS) has demonstrated faster administration, lower burden of data capture and reduced floor and ceiling effects compared to traditional Patient Reported Outcomes Measurements (PROMs). We investigated the suitability of PROMIS Mobility score in assessing physical function in the sequelae of childhood hip disease. Methods. In all, 266 adolscents (aged ≥ 12 years) and adults were identified with a prior diagnosis of childhood hip disease (either Perthes’ disease (n = 232 (87.2%)) or Slipped Capital Femoral Epiphysis (n = 34 (12.8%)) with a mean age of 27.73 years (SD 12.24). Participants completed the PROMIS Mobility Computer Adaptive Test, the Non-Arthritic Hip Score (NAHS), EuroQol five-dimension five-level questionnaire, and the Numeric Pain Rating Scale. We investigated the correlation between the PROMIS Mobility and other tools to assess use in this population and any clustering of outcome scores. Results. There was a strong correlation between the PROMIS Mobility and other established PROMs; NAHS (rs = 0.79; p < 0.001). There was notable clustering in PROMIS at the upper end of the distribution score (42.5%), with less seen in the NAHS (20.3%). However, the clustering was broadly similar between PROMIS Mobility and the comparable domains of the NAHS; function (53.6%), and activity (35.0%). Conclusion. PROMIS Mobility strongly correlated with other tools demonstrating convergent construct validity. There was clustering of physical function scores at the upper end of the distributions, which may reflect truncation of the data caused by participants having excellent outcomes. There were elements of disease not captured within PROMIS Mobility alone, and difficulties in differentiating those with the highest levels of function. Cite this article: Bone Jt Open 2021;2(12):1089–1095