Risk of acute renal failure and mortality after surgery for a fracture of the hip

Sarcopenia, a Risk Predictor of Postoperative Acute Kidney Injury in Elderly Patients after Hip Fracture Surgery: A Retrospective Analysis

Background and Objectives: Hip fracture surgery, which affects quality of life, can be a major challenge in geriatric populations. Although sarcopenia is known to be associated with postoperative outcomes, there are few studies on the association between sarcopenia and postoperative acute kidney injury (AKI) in this population. We investigated the association between sarcopenia and postoperative AKI in elderly patients following hip fracture surgery. Materials and Methods: We retrospectively reviewed the records of patients who underwent hip fracture surgery at our institution from March 2019 to December 2021. Patients under the age of 65, patients with no preoperative computed tomography (CT) scans and patients with inappropriate cross-sectional images for measurement were excluded. The psoas-lumbar vertebral index (PLVI), which is the ratio of the average area of both psoas muscles to the area of the fourth lumbar vertebral body, was measured from preoperative CT scans. Sarcopenia was defined as a PLVI within the lowest 25% for each sex, and patients were categorized into sarcopenic and nonsarcopenic groups. The occurrence of AKI was determined based on the serum creatinine level within postoperative day 7 using the Kidney Disease Improving Global Outcomes (KDIGO) guidelines. Univariate and multivariate logistic regression analyses were performed to evaluate the associations between clinical variables and the occurrence of AKI. Results: Among the 348 enrolled patients, 92 patients were excluded, and 256 patients were analyzed. The PLVI cutoff values for defining sarcopenia lower than 25% for male and female patients were 0.57 and 0.43, respectively. The overall incidence of AKI was 18.4% (47 patients), and AKI occurred more frequently in sarcopenic patients than in nonsarcopenic patients (29.7% vs. 14.6%, p = 0.007). According to the multivariate logistic regression, which included all variables with a p value < 0.05 in the univariate analysis and adjusted for age, body mass index (BMI) and American Society of Anesthesiologists (ASA) physical status, sarcopenia was revealed to be an independent predictor of postoperative AKI (odds ratio = 5.10, 95% confidence interval = 1.77-14.77; p = 0.003). Conclusions: Preoperative sarcopenia, which corresponds to the lowest quartile of PLVI values, is associated with postoperative AKI among elderly patients who underwent hip fracture surgery.

Acute kidney injury after hip fracture surgery in patients over 80 years of age

BACKGROUND

The aim of the study is to determine the rate of acute kidney injury (AKI) after hip fracture surgery over the age of 80 and to investigate the factors associated with AKI.

METHODS

From January 2015 to January 2020, 589 patients who underwent surgery of hip fractures at our institution were retrospectively reviewed. Serum creatinine (sCr) was analysed daily pre- and postoperatively during the hospital stay. Patients were divided into groups; AKI and non-AKI based on KDIGO (Kidney Disease Global Outcomes) criteria. The incidence, risk factors, and mortality of postoperative AKI were investigated.

RESULTS

Out of 589 patients, 58 developed an AKI (9.8%). Smoking (p: 0.004), pre and postoperative low albumin level (p < 0.05), pre- and postoperative high potassium level (p < 0.05), pre- and postoperative high urea levels (p < 0.05), high amount of intra-operative bleeding (p: 0.003) and prolonged surgery time (p: 0.003) were found to be risk factors associated with AKI. Although the mortality rate was higher in the AKI group, it was not statistically significant (p > 0.05).

CONCLUSION

AKI is a temporary but common complication following hip fracture surgery, which can also be predicted if risk factors are adequately observed. It typically increases the length of hospital stays, mortality and morbidity.

LEVEL OF EVIDENCE

Level III evidence, Retrospective comparative study.

Acute kidney injury after hip fracture in organ transplant recipients

BACKGROUND

This study aimed to investigate the incidence and risk factors of acute kidney injury (AKI) after hip fracture in organ transplant recipients.

METHODS

In this single-center retrospective cohort study, 795 elderly patients who underwent hip fracture surgery were enrolled. AKI was defined according to Acute Kidney Injury Network criteria. Among the 795 patients, 23 underwent kidney transplantation (KT) and 20 underwent liver transplantation (LT). The incidence of AKI, dialysis requirement, and renal recovery rate were investigated.

RESULTS

AKI occurred in 83 patients (10.5%), of whom 9 (39.1%), 3 (15%), and 71 (9.5%) were in the KT, LT, and non-transplantation groups, respectively. The incidence rates of AKI and severe AKI (17.4% vs. 1.4%) were significantly higher in the KT group than in the non-transplantation group (p = 0.001 for both). The renal recovery rate was significantly lower in the KT group than in the non-transplantation group (p = 0.033). The multivariate analysis revealed that male; body mass index; CKD; alkaline phosphatase; intraoperative hypotension; and history of KT were independent predictors of AKI development.

CONCLUSIONS

AKI and severe AKI after hip fracture occurred more frequently in the KT recipients with lower renal recovery rates. Transplanted kidneys are more vulnerable to AKI after hip fracture. This article is protected by copyright. All rights reserved.

Incidence and risk factors of acute kidney injury after femoral neck fracture in elderly patients: a retrospective case-control study

Background

Hip fracture is highly associated with disability and consequently, mortality in the elderly population. Postoperative acute kidney injury (AKI) is not unusual and is associated with considerable morbidity and mortality. We aimed to determine the incidences and potential risk factors for postoperative AKI in elderly patients with femoral neck fracture.

Methods

We retrospectively evaluated patients over 65 years of age who had been subjected to surgery for femoral neck fracture at Peking University People's Hospital from January 2015 to December 2019. Demographic characteristics and potential risk factors were collected. AKI was defined according to the Kidney Disease Improving Global Outcomes Guidelines (KDIGO).

Results

A total of 308 elderly patients with femoral neck fracture were included in the study. The overall incidence of postoperative AKI was 12% (37 cases). Through binary logistic regression analysis, adjusted for age, intraoperative blood loss and BMI, we identified that early postoperative albumin levels, hemoglobin changes and intraoperative hypotension are independent risk factors for postoperative AKI. The model considering the three factors can improve accuracy of predicting the possibility of developing AKI. The patients with AKI had a significantly higher mortality of 40.5% than those without AKI (24.0%, p < 0.001)

Conclusion

The incidence of postoperative AKI in elderly patients with femoral neck fracture was 12%. Independent risk factors for postoperative AKI included hemoglobin changes, early postoperative hypoalbuminemia and intraoperative hypotension. At the same time, postoperative AKI significantly increased mortality in elderly patients with femoral neck fracture. Taking multiple possible factors into consideration can better predict the possibility of elderly patients developing AKI after surgery.

The effect of intra-operative hypotension on acute kidney injury, postoperative mortality and length of stay following emergency hip fracture surgery

The association between intra-operative hypotension and postoperative acute kidney injury, mortality and length of stay has not been comprehensively evaluated in a large single-centre hip fracture population. We analysed electronic anaesthesia records of 1063 patients undergoing unilateral hip fracture surgery, collected from 2015 to 2018. Acute kidney injury, 3-, 30- and 365-day mortality and length of stay were evaluated to assess the relationship between intra-operative hypotension absolute values (≤ 55, 60, 65, 70 and 75 mmHg) and duration of hypotension. The rate of acute kidney injury was 23.7%, mortality at 3-, 30- and 365 days was 3.7%, 8.0% and 25.3%, respectively, and median (IQR [range]) length of stay 8 (6-12 [0-99]) days. Median (IQR [range]) time ≤ MAP 55, 60, 65, 70 and 75 mmHg was 0 (0-0.5[0-72.1]); 0 (0-4.4 [0-104.9]); 2.2 (0-8.7 [0-144.2]); 6.6 (2.2-19.7 [0-198.8]); 17.5 (6.6-37.1 [0-216.3]) minutes, and percentage of surgery time below these thresholds was 1%, 2.5%, 7.9%, 12% and 21% respectively. There were some univariate associations between hypotension and mortality; however, these were no longer evident in multivariable analysis. Multivariable analysis found no association between hypotension and acute kidney injury. Acute kidney injury was associated with male sex, antihypertensive medications and cardiac/renal comorbidities. Three-day mortality was associated with delay to surgery ? 48 hours, whilst 30-day and 365-day mortality was associated with delay to surgery ≥ 48 hours, impaired cognition and cardiac/renal comorbidities. While the rate of acute kidney injury was similar to other studies, use of vasopressors and fluids to reduce the time spent at hypotensive levels failed to reduce this complication. Intra-operative hypotension at the levels observed in this cohort may not be an important determinant of acute kidney injury, postoperative mortality and length of stay.

Perioperative acute kidney injury and urine output in lower limb arthroplasties

BACKGROUND

This study aimed to evaluate the occurrence and perioperative risk factors of acute kidney injury (AKI) in primary elective hip and knee and emergency hip arthroplasty patients. We also aimed to assess the effect of urine output (UOP) as a diagnostic criterion in addition to serum creatinine (sCr) levels. We hypothesized that emergency arthroplasties are prone to AKI and that UOP is an underrated marker of AKI.

METHODS

This retrospective, register-based study assessed 731 patients who underwent primary elective knee or hip arthroplasty and 170 patients who underwent emergency hip arthroplasty at Oulu University Hospital, Finland, between January 2016 and February 2017.

RESULTS

Of the elective patients, 18 (2.5%) developed AKI. The 1-year mortality rate was 1.5% in elective patients without AKI and 11.1% in those with AKI (P = .038). Of the emergency patients, 24 (14.1%) developed AKI. The mortality rate was 16.4% and 37.5% in emergency patients without and with AKI, respectively (P = .024). In an AKI subgroup analysis of the combined elective and emergency patients, the mortality rate was 31.3% (n = 5) in the sCr group (n = 16), 23.5% (n = 4) in the UOP group (n = 17), and 22.2% (n = 2) in AKI patients who met both the sCr and UOP criteria (n = 9).

CONCLUSION

Emergency hip arthroplasty is associated with an increased risk of AKI. Since AKI increases mortality in both elective and emergency arthroplasty, perioperative oliguria should also be considered as a diagnostic criterion for AKI. Focusing solely on sCr may overlook many cases of AKI.

Incidence, Risk-Factors and Associated Mortality of Complications in Orthogeriatric Co-Managed Inpatients

Introduction:

Pneumonia, thromboembolic and ischemic events, urinary tract infections (UTI), delirium and acute kidney injury (AKI) are common complications during the treatment of fragility fractures. In a 2 years-follow-up we determined the according incidence and risk factors of these and other complications in orthogeriatric inward patients, as well as the respective associated mortality.

Methods:

All patients treated on an orthogeriatric co-managed ward over the course of a year were included. Besides injury, therapy and geriatric assessment parameters, we evaluated the inward incidence of common complications. In a 2 years-follow-up the associated death rates were aquired. SPSS (IBM) was used to determine the importance of risk factors predisposing to the respective occurrence of a complication and accordingly determine it’s impact on the patients’ 1- and 2-years-mortality.

Results:

830 orthogeriatric patients were initially assessed with a remaining follow-up cohort of 661 (79.6%). We observed very few cases of thrombosis (0.6%), pulmonary embolism (0.5%), apoplex (0.5%) and myocardial infarction (0.8%). Pneumonia was seen in 42 (5.1%), UTI in 85 (10.2%), delirium in 186 (22.4%) and AKI in 91 (11.0%) patients. Consistently ADL on admission was found to be a relevant risk factor in the development of each complication. After adjustment only AKI showed a significant increased mortality risk of 1.60 (95%CI:1.086-2.350).

Discussion:

In our fracture-independent assessment of complications in the orthogeriatric treatment of inward patients we’ve seen very rare cases of cardiac and thrombotic complications. Typical fragility-fracture associated common events like pneumonia, UTI, delirium and AKI were still more incidental. No complication except AKI was associated to significant increased mortality risk.

Conclusions:

The relevance of orthogeriatric care in prevention and outcome of inward complications seems promising, needing still more controlled studies, evaluating not just hip fracture patients but more diverse groups. Consensus is needed in the scholar evaluation of orthogeriatric complications.

Predictors of postoperative acute kidney injury in patients undergoing hip fracture surgery: A systematic review and meta-analysis

BACKGROUND

The present study aimed to summarize the predictors of acute kidney injury (AKI) in patients after hip surgery.

METHODS

A literature search was performed using PubMed, EMBASE, Cochrane Library, and Web of Science for studies assessing the predictors of AKI after hip fracture surgery. Pooled odds ratio (OR) and mean difference (MD) of those who experienced AKI compared to those who did not were calculated for each variable. Evidence was assessed using the Newcastle-Ottawa Scale.

RESULTS

Ten studies with 34 potential factors were included in the meta-analysis. In the primary analysis, 12 factors were associated with AKI, comprising males (OR 1.25; 95% confidence interval (CI) 1.14-1.36), advanced age (MD 2.28; 95% CI 0.80-3.75), myocardial infarction (OR 1.39; 95% CI 1.18-1.63), hypertension (OR 1.46; 95% CI 1.13-1.89), diabetes (OR 1.84; 95% CI 1.40-2.42), chronic kidney disease (OR 3.66; 95% CI 2.21-6.07), hip arthroplasty (OR 1.35; 95% CI 1.22-1.50), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers use (OR 2.28; 95% CI 1.68-3.08), more intraoperative blood loss (MD 44.06; 95% CI 2.88-85.24), higher preoperative blood urea nitrogen levels (MD 5.29; 95% CI 3.38-7.20), higher preoperative serum creatinine levels (MD 0.4; 95% CI 0.26-0.53), and lower preoperative estimated glomerular filtration rate (MD -19.59; 95% CI -26.92--12.26). Another 13 factors related to AKI in individual studies were identified in the systematic review.

CONCLUSION

Related prophylaxis strategies should be implemented in patients involved with the above-mentioned characteristics to prevent AKI after hip surgery.

Bisphosphonates to reduce bone fractures in stage 3B+ chronic kidney disease: a propensity score-matched cohort study

BACKGROUND

Bisphosphonates are contraindicated in patients with stage 4+ chronic kidney disease. However, they are widely used to prevent fragility fractures in stage 3 chronic kidney disease, despite a lack of good-quality data on their effects.

OBJECTIVES

The aims of each work package were as follows. Work package 1: to study the relationship between bisphosphonate use and chronic kidney disease progression. Work package 2: to study the association between using bisphosphonates and fracture risk. Work package 3: to determine the risks of hypocalcaemia, hypophosphataemia, acute kidney injury and upper gastrointestinal events associated with using bisphosphonates. Work package 4: to investigate the association between using bisphosphonates and changes in bone mineral density over time.

DESIGN

This was a new-user cohort study design with propensity score matching.

SETTING AND DATA SOURCES

Data were obtained from UK NHS primary care (Clinical Practice Research Datalink GOLD database) and linked hospital inpatient records (Hospital Episode Statistics) for work packages 1-3 and from the Danish Odense University Hospital Databases for work package 4.

PARTICIPANTS

Patients registered in the data sources who had at least one measurement of estimated glomerular filtration rate of < 45 ml/minute/1.73 m2 were eligible. A second estimated glomerular filtration rate value of < 45 ml/minute/1.73 m2 within 1 year after the first was requested for work packages 1 and 3. Patients with no Hospital Episode Statistics linkage were excluded from work packages 1-3. Patients with < 1 year of run-in data before index estimated glomerular filtration rate and previous users of anti-osteoporosis medications were excluded from work packages 1-4.

INTERVENTIONS/EXPOSURE

Bisphosphonate use, identified from primary care prescriptions (for work packages 1-3) or pharmacy dispensations (for work package 4), was the main exposure.

MAIN OUTCOME MEASURES

Work package 1: chronic kidney disease progression, defined as stage worsening or starting renal replacement. Work package 2: hip fracture. Work package 3: acute kidney injury, hypocalcaemia and hypophosphataemia identified from Hospital Episode Statistics, and gastrointestinal events identified from Clinical Practice Research Datalink or Hospital Episode Statistics. Work package 4: annualised femoral neck bone mineral density percentage change.

RESULTS

Bisphosphonate use was associated with an excess risk of chronic kidney disease progression (subdistribution hazard ratio 1.12, 95% confidence interval 1.02 to 1.24) in work package 1, but did not increase the probability of other safety outcomes in work package 3. The results from work package 2 suggested that bisphosphonate use increased fracture risk (hazard ratio 1.25, 95% confidence interval 1.13 to 1.39) for hip fractures, but sensitivity analyses suggested that this was related to unresolved confounding. Conversely, work package 4 suggested that bisphosphonates improved bone mineral density, with an average 2.65% (95% confidence interval 1.32% to 3.99%) greater gain in femoral neck bone mineral density per year in bisphosphonate users than in matched non-users.

LIMITATIONS

Confounding by indication was a concern for the clinical effectiveness (i.e. work package 2) data. Bias analyses suggested that these findings were due to inappropriate adjustment for pre-treatment risk. work packages 3 and 4 were based on small numbers of events and participants, respectively.

CONCLUSIONS

Bisphosphonates were associated with a 12% excess risk of chronic kidney disease progression in participants with stage 3B+ chronic kidney disease. No other safety concerns were identified. Bisphosphonate therapy increased bone mineral density, but the research team failed to demonstrate antifracture effectiveness.

FUTURE WORK

Randomised controlled trial data are needed to demonstrate antifracture efficacy in patients with stage 3B+ chronic kidney disease. More safety analyses are needed to characterise the renal toxicity of bisphosphonates in stage 3A chronic kidney disease, possibly using observational data.

STUDY REGISTRATION

This study is registered as EUPAS10029.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 17. See the NIHR Journals Library website for further project information. The project was also supported by the National Institute for Health Research Biomedical Research Centre, Oxford.

Mortality Risk Assessment at the Admission in Patient With Proximal Femur Fractures: Electrolytes and Renal Function

In patients over 65y.o. who were surgically treated for a hip fracture, electrolytes have not been specifically studied as predictors of mortality. The main purpose of this study was to assess whether electrolytes and chronic kidney disease (CKD) stages, evaluated at admission, could represent a pre-operative prognostic factor in this population. Moreover, the role of epidemiological and clinical parameters was analyzed with and without a surgical timing stratification. This retrospective study included 746 patients. For each patient, their age, gender, fracture classification, Hb value, comorbidities, ASA class, chronic kidney disease, creatinine levels, electrolytes and surgical timing were collected. CKD-epi, MDRD, modified MDRD and BIS1 were used to obtain eGFR and CKD stages. All parameters were analyzed individually and in relation to the different surgical timing. Descriptive statistics, Chi-square test and survivability analysis with Kaplan Meier curve were used. In patients with a hip fracture non-significant association with increased mortality was shown for the following variables: Hb value, sodium values, calcium values, CKD stages and creatinine values. Otherwise altered kalemia was associated with a statistically significant increase in mortality as well as male gender, two or more comorbid medical conditions, advanced age (>75 years), higher ASA class. Surgery performed within 72h resulted in a statistically significant reduction in mortality at 6 months and, when performed in 24h-48h, a further reduction at 4 years. Age and ASA class statistically significant increased mortality regardless the surgical timing. Male patients operated after 48h from hospitalization were associated with a statistically significant increase in mortality rate. Two or more comorbidities were related to a statistically significant increased number of deaths when patients were treated after 96h. Altered kalemia values at hospitalization are associated with a statistically significant increase in mortality in patients operated after 72h from admission.

Factors associated with postoperative acute kidney injury after hip fractures in elderly patients

OBJECTIVES

Acute kidney injury (AKI) is a rare but serious complication after hip fractures. The aim of this study was to evaluate the incidence and the risk factors of postoperative AKI after hip fractures.

METHODS

From January 2011 to December 2016, 550 patients who underwent surgery of hip fractures at our institution were retrospectively reviewed. AKI was defined and classified by AKI Network (AKIN) Classification/Staging System. The incidence, mortality, and risk factors of postoperative AKI were investigated. Receiver operating characteristic curve analysis was conducted to evaluate the ability of markers in predicting AKI.

RESULTS

The incidence of postoperative AKI was 4.4% (25 cases). The mean onset of postoperative AKI was 8.0 ± 5.3 days and recovered after 7.0 ± 4.2 days after the occurrence of AKI. Of 25 patients with AKI, 6 patients (24.0%) died within 1 year after surgery. The independent risk factors for postoperative AKI are the estimated blood loss (EBL) (odds ratio (OR) 1.64; 95% confidence interval (CI) 1.33-2.58; p < 0.01) and postoperative level of albumin (OR 1.77; 95% CI 1.52-2.74; p < 0.01). The cutoff value of the serum albumin was <2.8 g/dL with a sensitivity of 88.0% and a specificity of 77.1%. The cutoff value of EBL was <766.5 mL with a sensitivity of 84.0% and a specificity of 66.3%.

CONCLUSION

Postoperative AKI after hip fractures had low incidences (4.4%) but high mortality (24.0%). The postoperative AKI was correlated with blood loss and low postoperative albumin levels.

Kidney Function Modifies the Effect of Intraoperative Opioid Dosage on Postoperative Delirium

BACKGROUND

There are few studies demonstrating how kidney function affects the risk of developing delirium in older adult surgical patients administered opioids. This study determined whether baseline kidney function influences the relationship between morphine equivalent dose and the development of delirium on postoperative day (POD) 2 in patients with hip fracture.

METHODS

This retrospective study analyzed emergency department (ED) estimated glomerular filtration rate (eGFR), perioperative serum creatinine, intravenous morphine equivalents, and POD2 delirium assessment by the Confusion Assessment Method in 652 patients aged 65 years or older without preoperative delirium. ED eGFR was used to divide subjects into groups by presence or absence of chronic kidney disease (CKD), and associations of opioid dose with POD2 delirium were compared using multivariable logistic regression.

RESULTS

POD2 delirium incidence was 29.8% (N = 194). Intraoperative and postanesthesia care unit (PACU) morphine equivalent dosage as well as ED eGFR were similar comparing patients with and without POD2 delirium. Age, American Society of Anesthesiologists status, and dementia were associated with delirium on POD2. The odds of POD2 delirium increased significantly with increase of intraoperative opioid in patients with CKD (odds ratio = 1.6; 95% confidence interval = 1.2-2.2), but not in patients without CKD (P-interaction = .04). PACU or POD1 opioid doses were not associated with POD2 delirium after covariate adjustment.

CONCLUSION

This study suggests that incremental increases in intraoperative opioids combined with CKD increase odds of POD2 delirium after hip fracture repair, compared with patients without CKD.

In-Hospital Postoperative Pneumonia Following Geriatric Intertrochanteric Fracture Surgery: Incidence and Risk Factors

Purpose

The in-hospital death rate in cases of hip fracture ranges from 6% to 10%. Pneumonia is a serious complication for hip fracture patients that contributes to longer hospital stays and higher mortality rates; however, the prevalence and risk factors are not well established. To address this issue, the present study investigated the incidence of and risk factors for in-hospital postoperative pneumonia (IHPOP) following geriatric intertrochanteric fracture surgery.

Patients and Methods

Information on 1495 geriatric patients (>65 years) who underwent intertrochanteric fracture surgery at our hospital between October 2014 and December 2018 was extracted from a prospective hip fracture database and reviewed. Demographic information, clinical variables including surgical data, and preoperative laboratory indices that could potentially influence IHPOP were analyzed. Receiver operating characteristic curve analysis was performed and the optimum cutoff value for quantitative data was determined. Univariate and multivariate analyses were carried out to identify risk factors for IHPOP.

Results

The incidence of IHPOP following geriatric intertrochanteric fracture surgery was 3.5% (53/1495 cases). The multivariate analysis showed that age >82 years (odds ratio [OR]=2.54, p=0.004), male sex (OR=2.13, p=0.017), chronic respiratory disease (OR=5.02, p<0.001), liver disease (OR=3.39, p=0.037), urinary tract infection (OR=8.46, p=0.005), creatine kinase (CK) MB>20 U/l (OR=2.31, p=0.020), B-type natriuretic peptide (BNP) ≥75 ng/l (OR=4.02, p=0.001), and d-dimer >2.26 mg/l (OR=2.69, p=0.002) were independent risks factor for the incidence of IHPOP following geriatric intertrochanteric fracture surgery.

Conclusion

The incidence of IHPOP was 3.5% following geriatric intertrochanteric fracture surgery; age, male sex, chronic respiratory disease, liver disease, urinary tract infection, CKMB, BNP, and d-dimer were significant risk factors. Targeted preoperative management based on these factors could reduce the risk of IHPOP and mortality in these patients.

ACUTE KIDNEY INJURY FOLLOWING SURGERY FOR HIP FRACTURE

Objective:

An observational study was carried out to determine the rate of acute kidney injury (AKI) following surgery for hip fracture at our institution and to look for factors associated with AKI.

Methods:

Preoperative creatinine values were compared to post-operative results for all patients who underwent surgery for hip fracture at our institution between 1^st January 2015 and 30^th September 2016. AKI was defined as an increase in postoperative creatinine, greater than or equal to 1.5 times the preoperative value within 7 days. Chi-squared test and Student’s t-test were used to look for factors associated with AKI.

Results:

Out of 500 patients, 96 developed an AKI (19.2%). Patients with chronic kidney disease (CKD) were more likely to develop AKI (30.8%) that those without it (17.2%, p = 0.018). Similarly, patients with 2 or more comorbidities were more likely to develop AKI (22.0%) than those without it (12.4%, p = 0.009). No statistically significant association was observed between type of surgery and AKI.

Conclusion:

A large proportion of patients following surgery for hip fracture developed AKI. Patients with CKD and the presence of 2 or more comorbidities had significantly higher rates of AKI. Level III evidence, Retrospective comparative study.

Simultaneous bilateral femoral neck fractures in a dialysis-dependent patient: case report and literature review

BACKGROUND

Simultaneous bilateral femoral neck fractures are extremely rare without obvious injury. Herein, we report the case of a patient on dialysis presenting with bilateral femoral neck fractures, which is a condition with high complication and mortality rates according to a review of the pertinent literature.

CASE PRESENTATION

We report the case a 47-year-old female with a history of 8 years of haemodialysis due to polycystic kidney disease who presented with bilateral hip pain during walking. The clinical history and results of physical and radiographic examinations of this patient are shown. Single-stage bilateral hemiarthroplasty was performed after a multidisciplinary team consultation. Three days after the operation, she could ambulate with a walker. The woman gradually regained her previous ability to walk over 6 months after surgery.

CONCLUSIONS

A multidisciplinary team consultation for perioperative management is necessary and effective in patients on dialysis. Early diagnosis with prompt surgical treatment could lead to favourable recovery.

Causes of in-hospital mortality after hip fractures in the elderly

OBJECTIVES

Although there are numerous studies reporting early mortality after hip fracture, the incidence and aetiology of in-hospital mortality following hip fractures is largely unknown. This study aimed to determine the causes and the incidence of in-hospital mortality in patients with a hip fracture who received surgical treatment.

METHODS

This was a multi-institutional retrospective study identifying 2464 consecutive patients >65 years of age who were treated for a hip fracture from 2000 to 2016 at 2 institutions. Revision surgeries were excluded. An electronic query followed by manual chart review was performed to collect patient demographics, Charlson comorbidity index (CCI), type of anaesthesia, and cause of death.

RESULTS

The overall in-hospital mortality rate for patients undergoing surgical intervention for an acute hip fracture was 3.0% (75/2464). The most common causes of death in descending order were: respiratory failure (n = 26), cardiac failure (n = 13), multiorgan failure (n = 6), septic shock (n = 6), pulmonary embolism (n = 5), end stage renal disease (n = 5) and others (n = 14). In-hopsital mortality was associated with older age (p = 0.001) and higher CCI scores (p = 0.001). There was no association with gender (p = 0.165), type of anaesthesia (p = 0.497), extracapsular versus intracapsular fracture (p = 0.627), pathologic versus non-pathologic fracture (0.799), or body mass index (p = 0.781).

CONCLUSION

This study demonstrated that hip fracture patients are at relatively high risk of in-hospital mortality following surgical intervention with a high proportion of patients succumbing to respiratory failure. The findings compel us to investigate strategies that can minimize mortality related to respiratory failure in this patient population such as minimising opioid use, early mobilisation, and implementing greater respiratory monitoring.

The Danish Multidisciplinary Hip Fracture Registry 13-Year Results from a Population-Based Cohort of Hip Fracture Patients

AIM OF THE REGISTRY

The aim of the Danish Multidisciplinary Hip Fracture Registry (DMHFR) is to collect data on processes of treatment, nursing care and rehabilitation as well as outcomes for patients with hip fracture in Denmark, and thereby monitor and improve the quality.

STUDY POPULATION

Hip fracture patients at age 65 or older that have undergone surgery with arthroplasty or internal fixation since 2004.

MAIN VARIABLES

DMHFR collects quality indicators and descriptive variables. Quality indicators include eight process performance measures within treatment, nursing care and rehabilitation, reflecting recommendations from the national clinical guideline for hip fracture patients, and three outcome measures including survival within 30-days, unplanned acute readmission within 30 days and reoperation within 2 years. Descriptive variables include a number of patient- and surgery-related characteristics. All data are collected prospectively.

RESULTS

By the end of 2018, the DMHFR included 86,438 hip fracture patients. Since 2006, all hospital departments in Denmark, treating patients with hip fracture, have reported improvement in quality of care and improvement in survival, and reoperation over time as well as high completeness of variables registration.

CONCLUSION

The DMHFR is a well-established nationwide clinical registry, which plays a key role for monitoring and improving hip fracture care in Denmark. The registry can further be linked to a range of other nationwide registries in order to answer a number of relevant clinical research questions.

Inflammation as a predictor of acute kidney injury and mediator of higher mortality after acute kidney injury in non-cardiac surgery

This retrospective cohort study examined the roles of inflammation in acute kidney injury (AKI). Serum albumin and C-reactive protein (CRP) were used as markers of inflammation. Adults who underwent non–cardiac surgery from 2007 to 2011 were included. Exclusion criteria were urological surgery, obstetric surgery, missing data, and pre-operative dialysis. Subjects were followed until the end of 2015 or loss to follow-up. Associations between pre–operative albumin or CRP and post-operative AKI or association between AKI and mortality were examined by logistic or Cox regression, respectively. Mediation analyses were performed using albumin and CRP as mediators. Among 4,538 subjects, 272 developed AKI. Pre-operative albumin was independently associated with AKI (odds ratio [95% confidence interval (CI)]: 0.63 [0.48–0.83]). During a median follow-up of 4.5 years, 649 died. AKI was significantly associated with mortality (hazard ratio [HR] [95% CI]: 1.58 [1.22–2.04]). Further adjustment for pre-operative albumin and CRP attenuated the association (HR [95% CI]: 1.28 [0.99–1.67]). The proportions explained by mediating effects of lnCRP and albumin were 29.3% and 39.2% and mediation effects were statistically significant. In conclusion, inflammation is a predictor of AKI and a mediator of mortality after AKI. Interventions targeting inflammation might improve outcomes of AKI.

Increased risk of mortality after postoperative infection in hip fracture patients

BACKGROUND

Postoperative infection is a common complication in hip fracture patients and the risk appears to have increased during the last decade. However, the impact of infection on mortality after hip fracture surgery remains unclear.

PURPOSE

We aimed to examine the association between infection (any, as well as specific infections), with all-cause mortality following hip fracture surgery.

METHODS

Using Danish nationwide registries, we conducted a population-based cohort study on 74,771 hip fracture patients ≥65 years old operated from 2005 to 2016. We included hospital-treated infection as a time-varying exposure, and calculated 30-days mortality rate per 1000 person-years (PY). We used time-varying Cox Proportional Hazard Regression to compute 30-days adjusted hazards ratios (aHRs) with 95% confidence interval (CI) comparing the mortality of hip fracture patients with and without infections. We adjusted for sex, age, comorbidities, medication use, and marital status.

RESULTS

Within 30 days of surgery, 9592 (12.8%) patients developed a hospital-treated infection. Among these, 30-days mortality was 8.43 per 1000 PY compared with 3.34 among patients without infection (aHR = 2.72, 95% CI: 2.56-2.88). For patients who developed pneumonia, aHR was 4.18 (95% CI: 3.91-4.48), whereas the aHR was 8.86 (95% CI: 7.88-9.95) for patients who developed systemic sepsis. For patients who sustained reoperation due to infection, aHR was 2.95 (95%CI: 1.88-4.64). The mortality was higher in infected vs. non-infected patients irrespective of patients' age, sex and comorbidity.

CONCLUSION

Infection within 30 days of hip fracture surgery is associated with substantially increased mortality risk. Further research should improve our knowledge about patients at increased risk and prevention measures for specific infections.

The what, when and how of orthopaedic registers: an introduction into register-based research

Establishment of orthopaedic registers started in 1975 and many registers have been initiated since. The main purpose of registers is to collect information on patients, implants and procedures in order to monitor and improve the outcome of the specific procedure.

Data validity reflects the quality of the registered data and consists of four major aspects: coverage of the register, registration completeness of procedures/patients, registration completeness of variables included in the register and accuracy of registered variables.

Survival analysis is often used in register studies to estimate the incidence of an outcome. The most commonly used survival analysis is the Kaplan–Meier survival curves, which present the proportion of patients who have not experienced the defined event (e.g. death or revision of a prosthesis) in relation to the time. Depending on the research question, competing events can be taken into account by using the cumulative incidence function. Cox regression analysis is used to compare survival data for different groups taking differences between groups into account.

When interpreting the results from observational register-based studies a number of factors including selection bias, information bias, chance and confounding have to be taken into account. In observational register-based studies selection bias is related to, for example, absence of complete follow-up of the patients, whereas information bias is related to, for example, misclassification of exposure (e.g. risk factor of interest) or/and outcome.

The REporting of studies Conducted using Observational Routinely-collected Data guidelines should be used for studies based on routinely-collected health data including orthopaedic registers.

Linkage between orthopaedic registers, other clinical quality databases and administrative health registers may be of value when performing orthopaedic register-based research.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180097

Long-term risk of adverse outcomes after acute kidney injury: a systematic review and meta-analysis of cohort studies using consensus definitions of exposure

Reliable estimates of the long-term outcomes of acute kidney injury (AKI) are needed to inform clinical practice and guide allocation of health care resources. This systematic review and meta-analysis aimed to quantify the association between AKI and chronic kidney disease (CKD), end-stage kidney disease (ESKD), and death. Systematic searches were performed through EMBASE, MEDLINE, and grey literature sources to identify cohort studies in hospitalized adults that used standardized definitions for AKI, included a non-exposed comparator, and followed patients for at least 1 year. Risk of bias was assessed by the Newcastle-Ottawa Scale. Random effects meta-analyses were performed to pool risk estimates; subgroup, sensitivity, and meta-regression analyses were used to investigate heterogeneity. Of 4973 citations, 82 studies (comprising 2,017,437 participants) were eligible for inclusion. Common sources of bias included incomplete reporting of outcome data, missing biochemical values, and inadequate adjustment for confounders. Individuals with AKI were at increased risk of new or progressive CKD (HR 2.67, 95% CI 1.99-3.58; 17.76 versus 7.59 cases per 100 person-years), ESKD (HR 4.81, 95% CI 3.04-7.62; 0.47 versus 0.08 cases per 100 person-years), and death (HR 1.80, 95% CI 1.61-2.02; 13.19 versus 7.26 deaths per 100 person-years). A gradient of risk across increasing AKI stages was demonstrated for all outcomes. For mortality, the magnitude of risk was also modified by clinical setting, baseline kidney function, diabetes, and coronary heart disease. These findings establish the poor long-term outcomes of AKI while highlighting the importance of injury severity and clinical setting in the estimation of risk.

Increased complications in geriatric patients with a fracture of the hip whose postoperative weight-bearing is restricted

Aims

The aims of this study were to evaluate the incidence of postoperatively restricted weight-bearing and its association with outcome in patients who undergo surgery for a fracture of the hip.

Patients and Methods

Patient aged > 60 years undergoing surgery for a hip fracture were identified in the 2016 National Surgical Quality Improvement Program (NSQIP) Hip Fracture Targeted Procedure Dataset. Analysis of the effect of restricted weight-bearing on adverse events, delirium, infection, transfusion, length of stay, return to the operating theatre, readmission and mortality within 30 days postoperatively were assessed. Multivariate regression analysis was used to adjust for confounding demographic, comorbid and procedural characteristics.

Results

Of the 4918 patients who met inclusion criteria, 3668 (63.53%) were allowed to weight-bear as tolerated postoperatively. Controlling for patient and procedural factors, multivariate odds of any adverse event, major adverse event, delirium, infection, transfusion, length of stay ≥ 75th percentile (six days) and mortality within 30 days were all higher in patients with weight-bearing restrictions. Notably, there were no differences for thromboembolic events, return to the operating theatre or readmission within 30 days between the groups.

Conclusion

Elderly patients with a fracture of the hip with postoperative weight-bearing restrictions have a significantly greater risk of developing most adverse events compared with those who are encouraged to weight-bear as tolerated. These findings emphasize the importance of immediate weight-bearing as tolerated to optimize the outcome in these frail patients; however nearly 25% of surgeons fail to meet this evidence-based guideline. Cite this article: Bone Joint J 2018;100-B:1377–84.

Early postoperative hypoalbuminemia is a risk factor for postoperative acute kidney injury following hip fracture surgery

INTRODUCTION

Acute kidney injury (AKI) is a common and serious complication after hip fracture surgery in older adults. Hypoalbuminemia is a known independent risk factor for AKI. However, few studies have investigated the relationship between early postoperative hypoalbuminemia and AKI after hip fracture surgery. Therefore, we sought to determine the incidence of and risk factors for AKI and the effects of early postoperative hypoalbuminemia on AKI incidence after surgery for hip fractures, especially intertrochanteric fractures of the proximal femur.

PATIENTS AND METHODS

In this retrospective cohort study from a single center, we reviewed the medical records of 481 consecutive patients (>60 years) who underwent surgery for intertrochanteric fracture of the proximal femur. Multiple logistic regression was performed to identify independent risk factors for AKI. After determining the cut-off value of the minimal level of postoperative serum albumin during the first two postoperative days, we divided the patients into two groups: group 1 included 251 patients whose minimal early postoperative serum albumin level was <2.9 g/dL during the first two postoperative days; and group 2 included 230 patients whose minimal early postoperative serum albumin level was ≥2.9 g/dL. The incidence of AKI was analyzed using inverse probability of treatment weighting (IPTW), propensity score matching (PSM), and propensity score matching weighting (PSMW) analyses.

RESULTS

The incidence of AKI, defined based on the Kidney Disease Improving Global Outcomes criteria, was 11.8% (n = 57). Chronic kidney disease and the minimal early postoperative serum albumin level <2.9 g/dL at any point during the first two postoperative days were independent risk factors for AKI. The IPTW, PSM, and PSMW analyses comparing the incidence of AKI between the two groups revealed that the minimal early postoperative serum albumin level <2.9 g/dL was significantly associated with AKI development (P < 0.001, P = 0.025, and P = 0.011, respectively).

CONCLUSION

The incidence of postoperative AKI was 11.8%. Our findings demonstrate that early postoperative hypoalbuminemia is an independent risk factor for AKI in patients undergoing surgery for intertrochanteric fracture of the proximal femur.

Quality of Care in Hip Fracture Patients: The Relationship Between Adherence to National Standards and Improved Outcomes

BACKGROUND

Optimizing the perioperative care of patients with a hip fracture is a key health-care priority. We aimed to determine whether adherence to the Scottish Standards of Care for Hip Fracture Patients (SSCHFP) was associated with improved patient outcomes.

METHODS

In this retrospective cohort study of prospectively collected data from the Scottish National Hip Fracture Audit, we assessed adherence to the SSCHFP in 21 Scottish hospitals over a 9-month period in 2014 and examined the effect of the guidelines on 30 and 120-day mortality, length of hospital stay, and discharge destination.

RESULTS

A total of 1,162 patients who were ≥50 years old and admitted with a hip fracture were included. There was a significant association between low adherence to the SSCHFP and increased mortality at 30 and 120 days (odds ratio [OR], 3.58 [95% confidence interval (CI), 1.75 to 7.32; p < 0.001] and 2.01 [95% CI, 1.28 to 3.12; p = 0.003], respectively). Low adherence was associated with a reduced likelihood of a short length of stay (OR, 0.58; 95% CI, 0.42 to 0.78; p < 0.0001), but increased odds of discharge to a high-care setting (OR, 1.63; 95% CI, 1.12 to 2.36; p = 0.01). Early physiotherapy input and occupational therapy input were associated with a reduced likelihood of discharge to a high-care setting (OR, 0.64 [95% CI, 0.44 to 0.98; p = 0.04] and 0.34 [95% CI, 0.23 to 0.48; p <0.001], respectively).

CONCLUSIONS

Adherence to the SSCHFP is associated with better patient outcomes. These findings confirm the clinical utility of the SSCHFP and support their use as a benchmarking tool to improve quality of care for hip fractures.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Mortality and cause of death postoperatively in patients with a hip fracture

Aims

The aim of this study was to compare the rate of mortality and causes of death in Korean patients who undergo surgery for a fracture of the hip, up to 11 years after the injury, with a control group from the general population.

Materials and Methods

National cohort data from Korean Health Insurance Review and Assessment Service – National Sample Cohort were used. A ratio of 1:4 matched patients with a fracture who underwent surgery (3383, fracture group) between 2003 and 2012, and controls (13 532) were included. The matches were processed for age, gender, income, and region of residence. We also undertook analyses of subgroups according to age and gender. The mean follow-up was 4.45 years (1 to 11).

Results

The prevalence of hypertension, diabetes, and stroke was significantly higher in the fracture group and dyslipidemia in the controls. Both crude and adjusted hazard ratios (HR) for the rate of mortality in the fracture group were > 2 (crude HR 2.03, 95% confidence interval (CI) 1.91 to 2.17, p < 0.001; adjusted HR 2.07, 95% CI 1.94 to 2.21, p < 0.001). The HRs were also > 2 for both men and women, and for both those aged ≥ 50 years and < 50 years. However, for those aged < 50 years, they were insignificant. The rates of mortality due to all 11 major causes of death classified following Korean standard classification of diseases were significantly higher in the fracture group compared with the control group, except those in the mental and behavioral disorders category.

Conclusion

The rate of mortality in the fracture group was significantly higher than in the control group up to 11 years after the surgery. The rate of death due to almost every major cause was significantly higher in the fracture group compared with the control group. Cite this article: Bone Joint J 2018;100-B:436–42.

Excess risk of venous thromboembolism in hip fracture patients and the prognostic impact of comorbidity

Hip fracture patients were at increased excess risk of venous thromboembolism (VTE) up to 1 year following hip fracture. During the first year, interaction between hip fracture and comorbidity was observed among patients with severe and very severe comorbidity.

INTRODUCTION

We compared the risk of VTE in hip fracture patients with that in the general population. We also examined whether and to what extent the association between hip fracture and VTE varied by comorbidity level.

METHODS

Nationwide cohort study based on Danish health registries, 1995-2015. We identified hip fracture patients (n = 110,563) and sampled a comparison cohort without hip fracture from the general population (n = 552,774). Comorbidity was assessed using the Charlson comorbidity index. We calculated attributable fraction, as the proportion of the VTE rate, among persons exposed to both hip fracture and comorbidity, attributed to exposure interaction.

RESULTS

The cumulative incidences of VTE were 0.73% within 30 days and 0.83% within 31-365 days among hip fracture patients, and 0.05 and 0.43% in the general population. Adjusted hazard ratios (HRs) of VTE among hip fracture patients were 17.29 [95% confidence interval (CI) 14.74-20.28] during the first 30 days and 2.13 (95% CI 1.95-2.32) during 31-365 days following hip fracture. The relative risks of VTE were 1.03 (95% CI 0.96-1.11) and 1.11 (95% CI 1.00-1.23) after 1-5 years and 6-10 years. During the first 30 days and 31-365 days, 14%/28% of VTE rates and 5%/4% of VTE rates were attributable to the interaction between hip fracture and severe/very severe comorbidity, respectively. Mortality risks within 30 days of VTE were 29.4% in hip fracture and 11.0% in general population cohorts.

CONCLUSIONS

Hip fracture patients were at increased excess risk of VTE up to 1 year following their fracture. During the first year, interaction between hip fracture and comorbidity was observed among patients with severe and very severe comorbidity.

Impact of body mass index on risk of acute kidney injury and mortality in elderly patients undergoing hip fracture surgery

The literature is limited regarding risk factors for acute kidney injury (AKI) and mortality in hip fracture patients, although AKI is common in these patients. While obese patients were at increased risk of AKI, underweight patients with and without AKI had elevated mortality for up to 1 year after hip fracture surgery, compared with normal-weight patients.

INTRODUCTION

This study aimed to examine risk of postoperative AKI and subsequent mortality, by body mass index (BMI) level, in hip fracture surgery patients aged 65 and over.

METHODS

A regional cohort study using medical databases was used. We included all patients who underwent surgery to repair a hip fracture during the years 2005-2011 (n = 13,529) at hospitals in Northern Denmark. We calculated cumulative risk of AKI by BMI level during 5 days postsurgery and subsequent short-term (6-30 days postsurgery) and long-term (31-365 days post-surgery) mortality. We calculated crude and adjusted hazard ratios (aHRs) for AKI and death with 95% confidence intervals (CIs), comparing underweight, overweight, and obese patients with normal-weight patients.

RESULTS

Risks of AKI within five postoperative days were 11.9, 10.1, 12.5, and 17.9% for normal-weight, underweight, overweight, and obese patients, respectively. Among those who developed AKI, short-term mortality was 14.1% for normal-weight patients compared to 23.1% for underweight (aHR 1.7 (95% CI 1.2-2.4)), 10.7% for overweight (aHR 0.9 (95% CI 0.6-1.1)), and 15.2% for obese (aHR 0.9 (95% CI 0.6-1.4)) patients. Long-term mortality was 24.5% for normal-weight, 43.8% for underweight (aHR 1.6 (95% CI 1.0-2.6)), 20.5% for overweight (aHR 0.8 (95% CI 0.6-1.2)), and 21.4% for obese (aHR 1.1 (95% CI 0.7-1.8) AKI patients. Similar associations between BMI and mortality were observed among patients without postoperative AKI, although the absolute mortality risk estimates by BMI were considerably lower in patients without than in those with AKI.

CONCLUSIONS

Obese patients were at increased risk of AKI compared with normal-weight patients. Among patients with and without postoperative AKI, overweight and obesity were not associated with mortality. Compared to normal-weight patients, underweight patients had elevated mortality for up to 1 year after hip fracture surgery irrespective of the presence of AKI. The absolute mortality risks were higher in all BMI groups with the presence of AKI.