Aims. Hospital case volume is shown to be associated with postoperative outcomes in various types of surgery. However, conflicting results of volume-outcome relationship have been reported in hip fracture surgery. This retrospective cohort study aimed to evaluate the association between hospital case volume and postoperative outcomes in patients who had hip fracture surgery. We hypothesized that higher case volume would be associated with lower risk of in-hospital and one-year mortality after hip fracture surgery. Methods. Data for all patients who underwent surgery for hip fracture from January 2008 to December 2016 were extracted from the Korean National Healthcare Insurance Service database. According to mean annual case volume of surgery for hip fracture, hospitals were classified into very low (< 30 cases/year), low (30 to 50 cases/year), intermediate (50 to 100 cases/year), high (100 to 150 cases/year), or very high (> 150 cases/year) groups. The association between hospital case volume and in-hospital mortality or one-year mortality was assessed using the logistic regression model to adjust for age, sex, type of fracture, type of anaesthesia, transfusion, comorbidities, and year of surgery. Results. Between January 2008 and December 2016, 269,535 patients underwent hip fracture surgery in 1,567 hospitals in Korea. Compared to hospitals with very high volume, in-hospital mortality rates were significantly higher in those with high volume (odds ratio (OR) 1.10, 95% confidence interval ((CI) 1.02 to 1.17, p = 0.011), low volume (OR 1.22, 95% CI 1.14 to 1.32, p < 0.001), and very low volume (OR 1.25, 95% CI 1.16 to 1.34, p < 0.001). Similarly, hospitals with lower case volume showed higher one-year mortality rates compared to hospitals with very high case volume (low volume group, OR 1.15, 95% CI 1.11 to 1.19, p < 0.001; very low volume group, OR 1.10, 95% CI 1.07 to 1.14, p < 0.001). Conclusion. Higher hospital case volume of hip fracture surgery was associated with lower in-hospital mortality and one-year mortality in a dose-response fashion. Cite this article: Bone Joint J 2020;102-B(10):1384–1391

Aims. We aimed to determine the effect of dementia and Parkinson’s disease on one, three and 12-month mortality following surgery for fracture of the hip in elderly patients from an Asian population. Patients and Methods. Using a random sample of patients taken from the Taiwan National Health Insurance Research Database, this retrospective cohort study analyzed the data on 6626 elderly patients who sustained a fracture of the hip between 1997 and 2012 who had ICD-9 codes within the general range of hip fracture (820.xx). We used Cox regression to estimate the risk of death associated with dementia, Parkinson’s disease or both, adjusting for demographic, clinical, treatment, and provider factors. Results. Among 6626 hip fracture patients, 10.20% had dementia alone, 5.60% had Parkinson’s disease alone, and 2.67% had both. Corresponding one-year mortality rates were 15.53%, 11.59%, and 15.82%, compared with 9.22% for those without neurological illness. Adjusted hazard ratio for one-year mortality was 1.45 (95% confidence intervals (CI) 1.17 to 1.79) for those with dementia, and 1.57 (95% CI 1.07 to 2.30) with both dementia and Parkinson’s disease versus patients with neither. There was no significant association with death for Parkinson’s disease alone. Age, male gender and comorbidities were also associated with a higher risk of mortality. Conclusion. Dementia, with or without Parkinson’s disease, is an independent predictor of mortality following surgery for fractures of the hip. Age, male gender and comorbidities also increase the risk of death. Parkinson’s disease alone has no significant effect. Cite this article: Bone Joint J 2018;100-B:1220–6

The aim of this study was to examine the rates and potential risk factors for 28-day re-admission following a fracture of the hip at a high-volume tertiary care hospital. We retrospectively reviewed 467 consecutive patients with a fracture of the hip treated in the course of one year. Causes and risk factors for unplanned 28-day re-admissions were examined using univariate and multivariate analysis, including the difference in one-year mortality. A total of 55 patients (11.8%) were re-admitted within 28 days of discharge. The most common causes were pneumonia in 15 patients (27.3%), dehydration and renal dysfunction in ten (18.2%) and deteriorating mobility in ten (18.2%). A moderate correlation was found between chest infection during the initial admission and subsequent re-admission with pneumonia (r = 0.44, p < 0.001). A significantly higher mortality rate at one year was seen in the re-admission group (41.8% (23 of 55) vs 18.7% (77 of 412), p < 0.001). Logistic regression analysis identified advancing age, admission source, and the comorbidities of diabetes and neurological disorders as the strongest predictors for re-admission. Early re-admission following hip fracture surgery is predominantly due to medical causes and is associated with higher one-year mortality. The risk factors for re-admission can have implications for performance-based pay initiatives in the NHS. Multidisciplinary management in reducing post-operative active clinical problems may reduce early re-admission

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. Femoral periprosthetic fractures are rising in incidence. Their management is complex and carries a high associated mortality. Unlike native hip fractures, there are no guidelines advising on time to theatre in this group. We aim to determine whether delaying surgical intervention influences morbidity or mortality in femoral periprosthetic fractures. Methods. We identified all periprosthetic fractures around a hip or knee arthroplasty from our prospectively collated database between 2012 and 2021. Patients were categorized into early or delayed intervention based on time from admission to surgery (early = ≤ 36 hours, delayed > 36 hours). Patient demographics, existing implants, Unified Classification System fracture subtype, acute medical issues on admission, preoperative haemoglobin, blood transfusion requirement, and length of hospital stay were identified for all patients. Complication and mortality rates were compared between groups. Results. A total of 365 patients were identified: 140 in the early and 225 in the delayed intervention group. Mortality rate was 4.1% at 30 days and 19.2% at one year. There was some indication that those who had surgery within 36 hours had a higher mortality rate, but this did not reach statistical significance at 30 days (p = 0.078) or one year (p = 0.051). Univariate analysis demonstrated that age, preoperative haemoglobin, acute medical issue on admission, and the presence of postoperative complications influenced 30-day and one-year mortality. Using a multivariate model, age and preoperative haemoglobin were independently predictive factors for one-year mortality (odds ratio (OR) 1.071; p < 0.001 and OR 0.980; p = 0.020). There was no association between timing of surgery and postoperative complications. Postoperative complications were more likely with increasing age (OR 1.032; p = 0.001) and revision arthroplasty compared to internal fixation (OR 0.481; p = 0.001). Conclusion. While early intervention may be preferable to reduce prolonged immobilization, there is no evidence that delaying surgery beyond 36 hours increases mortality or complications in patients with a femoral periprosthetic fracture. Cite this article: Bone Jt Open 2024;5(6):452–456

Aims. To determine if patient ethnicity among patients with a hip fracture influences the type of fracture, surgical care, and outcome. Methods. This was an observational cohort study using a linked dataset combining data from the National Hip Fracture Database and Hospital Episode Statistics in England and Wales. Patients’ odds of dying at one year were modelled using logistic regression with adjustment for ethnicity and clinically relevant covariates. Results. A total of 563,640 patients were included between 1 April 2011 and 1 October 2020. Of these, 476,469 (85%) had a coded ethnicity for analysis. Non-white patients tended to be younger (mean 81.2 vs 83.0 years), and were more commonly male (34.9% vs 28.5%; p < 0.001). They were less likely to be admitted from institutional care (12.9% vs 21.8%; p < 0.001), to have normal cognition (53.3% vs 62.0%; p < 0.001), and to be free of comorbidities (22.0% vs 26.8%; p < 0.001), but were more likely to be from the most deprived areas (29.4% vs 17.3%; p < 0.001). Non-white patients were more likely to experience delay to surgery for medical reasons (14.8% vs 12.7%; p < 0.001), more likely to be treated with an intramedullary nail or a sliding hip screw (52.5% vs 45.1%; p < 0.001), and less likely to be mobilized by the day after surgery (74.3% vs 79.0%; p < 0.001). Mortality was higher among non-white inpatients (9.2% vs 8.4% for white), but was lower at one year after hip fracture (26.6% vs 30.3%). Conclusion. Our study identified serious problems with the quality of NHS ethnicity data. Despite this, we have shown that there is complex variation in case-mix and hip fracture morphology between ethnic groups. We have also identified variations in care received between ethnic groups, and that disparities in healthcare may contribute to poorer outcome. Inpatient mortality is higher in non-white patients, although this finding reverses after discharge, and one-year mortality is lower. Patients from ethnic minority backgrounds experience disparities in healthcare, however at one year postoperatively non-white patients have a statistically significant lower mortality after controlling for relevant clinical covariates. Cite this article: Bone Joint J 2024;106-B(10):1182–1189

Objectives. To determine the morbidity and mortality outcomes of patients presenting with a fractured neck of femur in an Australian context. Peri-operative variables related to unfavourable outcomes were identified to allow planning of intervention strategies for improving peri-operative care. Methods. We performed a retrospective observational study of 185 consecutive adult patients admitted to an Australian metropolitan teaching hospital with fractured neck of femur between 2009 and 2010. The main outcome measures were 30-day and one-year mortality rates, major complications and factors influencing mortality. . Results. The majority of patients were elderly, female and had multiple comorbidities. Multiple peri-operative medical complications were observed, including pre-operative hypoxia (17%), post-operative delirium (25%), anaemia requiring blood transfusion (28%), representation within 30 days of discharge (18%), congestive cardiac failure (14%), acute renal impairment (12%) and myocardial infarction (4%). Mortality rates were 8.1% at 30 days and 21.6% at one year. Factors predictive of one-year mortality were American Society of Anesthesiologists (ASA) score (odds ratio (OR) 4.2 (95% confidence interval (CI) 1.5 to 12.2)), general anaesthesia (OR 3.1 (95% CI 1.1 to 8.5)), age > 90 years (OR 4.5 (95% CI 1.5 to 13.1)) and post-operative oliguria (OR 3.6 (95% CI 1.1 to 11.7)). Conclusions. Results from an Australian metropolitan teaching hospital confirm the persistently high morbidity and mortality in patients presenting with a fractured neck of femur. Efforts should be aimed at medically optimising patients pre-operatively and correction of pre-operative hypoxia. This study provides planning data for future interventional studies. Cite this article: Bone Joint Res 2013;2:162–8

Aims. The aims of this study were to investigate the mortality following a proximal humeral fracture. Data from a large population-based fracture register were used to quantify 30-day, 90-day, and one-year mortality rates after a proximal humeral fracture. Associations between the risk of mortality and the type of fracture and its treatment were assessed, and mortality rates were compared between patients who sustained a fracture and the general population. Methods. All patients with a proximal humeral fracture recorded in the Swedish Fracture Register between 2011 and 2017 were included in the study. Those who died during follow-up were identified via linkage with the Swedish Tax Agency population register. Age- and sex-adjusted controls were retrieved from Statistics Sweden and standardized mortality ratios (SMRs) were calculated. Results. A total of 18,452 patients who sustained a proximal humeral fracture were included. Their mean age was 68.8 years (16 to 107) and the majority (13,729; 74.4%) were women. A total of 310 (1.68%) died within 30 days, 615 (3.33%) within 90 days, and 1,445 (7.83%) within one year after the injury. The mortality in patients sustaining a fracture and the general population was 1,680/100,000 and 326/100,000 at 30 days, 3,333/100,000 and 979/100,000 at 90 days, and 7,831/100,000 and 3,970/100,000 at one year, respectively. Increasing age, male sex, low-energy trauma, type A fracture, concomitant fractures, and non-surgical treatment were all independent factors associated with an increased risk of mortality. Conclusion. Compared with the general population, patients sustaining a proximal humeral fracture have a significantly higher risk of mortality up to one year after the injury. The risk of mortality is five times higher during the first 30 days, diminishing to two times higher at one year, suggesting that these patients constitute a strikingly frail group, in whom appropriate immediate management and medical optimization are required. Cite this article: Bone Joint J 2020;102-B(11):1484–1490

Aims. The aim of this study was to investigate mortality and risk of intraoperative medical complications depending on delay to hip fracture surgery by using data from the Norwegian Hip Fracture Register (NHFR) and the Norwegian Patient Registry (NPR). Patients and Methods. A total of 83 727 hip fractures were reported to the NHFR between 2008 and 2017. Pathological fractures, unspecified type of fractures or treatment, patients less than 50 years of age, unknown delay to surgery, and delays to surgery of greater than four days were excluded. We studied total delay (fracture to surgery, n = 38 754) and hospital delay (admission to surgery, n = 73 557). Cox regression analyses were performed to calculate relative risks (RRs) adjusted for sex, age, American Society of Anesthesiologists (ASA) classification, type of surgery, and type of fracture. Odds ratio (OR) was calculated for intraoperative medical complications. We compared delays of 12 hours or less, 13 to 24 hours, 25 to 36 hours, 37 to 48 hours, and more than 48 hours. Results. Mortality remained unchanged when total delay was less than 48 hours. Total delay exceeding 48 hours was associated with increased three-day mortality (RR 1.69, 95% confidence interval (CI) 1.23 to 2.34; p = 0.001) and one-year mortality (RR 1.06, 95% CI 1.04 to 1.22; p = 0.003). More intraoperative medical complications were reported when hospital delay exceeded 24 hours. Conclusion. Hospitals should operate on patients within 48 hours after fracture to reduce mortality and intraoperative complications. Cite this article: Bone Joint J 2019;101-B:1129–1137

Aims. This study describes and compares the operative management and outcomes in a consecutive case series of patients with dislocated hemiarthroplasties of the hip, and compares outcomes with those of patients not sustaining a dislocation. Patients and Methods. Of 3326 consecutive patients treated with hemiarthroplasty for fractured neck of femur, 46 (1.4%) sustained dislocations. Of the 46 dislocations, there were 37 female patients (80.4%) and nine male patients (19.6%) with a mean age of 83.8 years (66 to 100). Operative intervention for each, and subsequent dislocations, were recorded. The following outcome measures were recorded: dislocation; mortality up to one-year post-injury; additional surgery; residential status; mobility; and pain score at one year. Results. Of 43 dislocations, 30 (70%) occurred within one month and 42 (98%) occurred within three months of hip fracture surgery. Seven (16%) of these patients were treated with a single closed reduction and sustained no further dislocations. Four (9%) were treated with open reduction and experienced no further dislocations. Three (7%) hips were left dislocated and the remaining 32 (74%) patients required additional surgery of further closed reduction, revision, or excision arthroplasty. The one-year mortality rates for patients treated with two or fewer reductions (open or closed), successful revision arthroplasty, and excision arthroplasty were 3/14 (21%), 1/7 (14%), and 8/14 (57%) respectively. The only statistically significant difference in mortality was the difference between patients who did not sustain a dislocation and those who did and were treated by excision arthroplasty (p = 0.03). Patients treated by excision arthroplasty had the greatest reduction in mobility scores and highest pain scores. The excision arthroplasty group also included the greatest proportion of patients not able to mobilize and the smallest proportion of patients remaining in their own home. Conclusion. Most dislocations of hemiarthroplasties of the hip occur within one month of surgery. Closed reduction is generally unsuccessful. For those patients with unsuccessful closed reduction, revision arthroplasty should be considered when possible, as this results in a better functional outcome with a lower mortality than excision arthroplasty

Aims. Infection after surgery increases treatment costs and is associated with increased mortality. Hip fracture patients have historically had high rates of methicillin-resistant Staphylococcus aureus (MRSA) colonization and surgical site infection (SSI). This paper reports the impact of routine MRSA screening and the “cleanyourhands” campaign on rates of MRSA SSI and patient outcome. Methods. A total of 13,503 patients who presented with a hip fracture over 17 years formed the study population. Multivariable logistic regression was performed to determine risk factors for MRSA and SSI. Autoregressive integrated moving average (ARIMA) modelling adjusted for temporal trends in rates of MRSA. Kaplan-Meier estimators were generated to assess for changes in mortality. Results. In all, 6,189 patients were identified before the introduction of screening and 7,314 in the post-screening cohort. MRSA infection fell from 69 cases to 15 in the post-screening cohort (p < 0.001). The ARIMA confirmed a significant reduction in MRSA SSI post-screening (p = 0.043) but no significant impact after hand hygiene alone (p = 0.121). Overall SSI fell (2.4% to 1.5%), however deep infection increased slightly (0.89% to 1.06%). ARIMA showed neither intervention affected overall SSI (“cleanyourhands” -0.172% (95% confidence interval (CI) -0.39% to 0.21); p = 0.122, screening -0.113% per year, (95% CI -0.34 to 0.12); p = 0.373). One-year mortality after deep SSI was unchanged after screening (50% vs 45%; p = 0.415). Only warfarinization (OR 3.616 (95% CI 1.366 to 9.569); p = 0.010) and screening (OR 0.189 (95% CI 0.086 to 0.414); p < 0.001) were significant covariables for developing MRSA SSI. Conclusion. While screening and decolonization may reduce MRSA-associated SSI, the benefit to patient outcome remains unclear. Overall deep SSI remains an unsolved problem that has seen little improvement over time. Preventing other hospital-associated infections should not be forgotten in the fight against MRSA. Cite this article: Bone Joint J 2021;103-B(1):170–177

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

Prospective data on hip fracture from 3686 patients at a United Kingdom teaching hospital were analysed to investigate the risk factors, financial costs and outcomes associated with deep or superficial wound infections after hip fracture surgery. In 1.2% (41) of patients a deep wound infection developed, and 1.1% (39) had a superficial wound infection. A total of 57 of 80 infections (71.3%) were due to Staphylococcus aureus and 39 (48.8%) were due to MRSA. No statistically significant pre-operative risk factors were detected. Length of stay, cost of treatment and pre-discharge mortality all significantly increased with deep wound infection. The one-year mortality was 30%, and this increased to 50% in those who developed an infection (p < 0.001). A deep infection resulted in doubled operative costs, tripled investigation costs and quadrupled ward costs. MRSA infection increased costs, length of stay, and pre-discharge mortality compared with non-MRSA infection

Fractures of the tibial shaft are common injuries, but there are no long-term outcome data in the era of increased surgical management. The aim of this prospective study was to assess the clinical and functional outcome of this injury at 12 to 22 years. Secondary aims were to determine the short- and long-term mortality, and if there were any predictors of clinical or functional outcome or mortality. From a prospective trauma database of 1502 tibial shaft fractures in 1474 consecutive adult patients, we identified a cohort of 1431 tibial diaphyseal fractures in 1403 patients, who fitted our inclusion criteria. There were 1024 men, and mean age at injury was 40.6 years. Fractures were classified according to the AO system, and open fractures graded after Gustilo and Anderson. Requirement of fasciotomy, time to fracture union, complications, incidence of knee and ankle pain at long-term follow-up, changes in employment and the patients’ social deprivation status were recorded. Function was assessed at 12 to 22 years post-injury using the Short Musculoskeletal Function Assessment and short form-12 questionnaires. Long-term functional outcome data was available for 568 of the surviving patients, 389 were deceased and 346 were lost to follow-up. Most fractures (90.7%, n = 1363) united without further intervention. Fasciotomies were performed in 11.5% of patients; this did not correlate with poorer functional outcome in the long term. Social deprivation was associated with a higher incidence of injury but had no impact on long-term function. The one-year mortality in those over 75 years of age was 29 (42%). At long-term follow-up, pain and function scores were good. However, 147 (26%) reported ongoing knee pain, 62 (10%) reported ankle pain and 97 (17%) reported both. Such joint pain correlated with poorer functional outcome. Cite this article: Bone Joint J 2014;96-B:1370–7

Aims

This study aimed to compare mortality in trochanteric AO/OTA A1 and A2 fractures treated with an intramedullary nail (IMN) or sliding hip screw (SHS). The primary endpoint was 30-day mortality, with secondary endpoints at 0 to 1, 2 to 7, 8 to 30, 90, and 365 days.

Aims

The aim of this study was to report the three-year follow-up for a series of 400 patients with a displaced intracapsular fracture of the hip, who were randomized to be treated with either a cemented polished tapered hemiarthroplasty or an uncemented hydroxyapatite-coated hemiarthroplasty.

Aims

Ankle fractures are common injuries and the third most common fragility fracture. In all, 40% of ankle fractures in the frail are open and represent a complex clinical scenario, with morbidity and mortality rates similar to hip fracture patients. They have a higher risk of complications, such as wound infections, malunion, hospital-acquired infections, pressure sores, veno-thromboembolic events, and significant sarcopaenia from prolonged bed rest.

Aims

The aim of this study was to describe the current pathways of care for patients with a fracture of the hip in five low- and middle-income countries (LMIC) in South Asia (Nepal and Sri Lanka) and Southeast Asia (Malaysia, Thailand, and the Philippines).

Aims

Several previously identified patient-, injury-, and treatment-related factors are associated with the development of nonunion in distal femur fractures. However, the predictive value of these factors is not well defined. We aimed to assess the predictive ability of previously identified risk factors in the development of nonunion leading to secondary surgery in distal femur fractures.

Aims

To investigate if preoperative CT improves detection of unstable trochanteric hip fractures.