Session 1: Trauma Hip Fractures

16. November
09:00 - 10:30
Lokale: Vingsal 1
Chair: Michala Skovlund and Michael Brix

1. Reduced dislocation rate with a piriformis sparing posterior approach in hemiarthroplasty for femoral neck fractures
Bjarke Viberg¹, Erik Qvist Kristensen¹, Thomas Gaarsdal², Henrik Palm³,4, Charlotte Densing Petersen³, Søren Overgaard³,4, Thomas Giver Jensen³
¹Department of Orthopaedic Surgery and Traumatology, Lillebaelt Hospital - University Hospital of Southern Denmark; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital²; Department of Orthopaedic Surgery and Traumatology, Copenhagen University Hospital, Bispebjerg³; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen4

Background: Danish femoral neck fracture (FFN) patients treated with hemiarthroplasty (HA) have one of the highest risk of dislocation in the world due to use of the posterior approach (PA). An option could be changing to an anterior capsule approach but perhaps there is a more feasible way to lower the dislocation rate by a piriformis sparing posterior approach (PSPA).
Aim: To compare the PSPA to the PA in FFN patients treated with HA concerning dislocations, reoperations, and total surgery related complications.
Materials and Methods: On the 1st of January 2019, the PSPA was introduced at two hospitals as a new treatment standard. A sample size was calculated on the basis of a 5 percent point reduction in dislocations and due to an expected 25% mortality rate, 264 in each group was needed. A 2-year inclusion period with 1-year follow-up was therefore estimated including a historical cohort 2 years prior to the PPPA introduction. Data was retrieved from the hospitals administrative databases and all health care journals as well as x-ray images were reviewed. An adjusted relative risk (RR) was calculated using Cox regression given with 95% confidence interval.
Results: There were 650 FFN patients treated with HA, 72% were women, and 42% were more than 85 years. There was no baseline difference between the PSPA and PA group regarding sex, age, comorbidity, BMI, smoking, alcohol, mobility, length of surgery, blood loss, implant positioning or mortality. There was a difference in type of HA due to a change in one hospital but also more surgeons in training in the PSPA group. The dislocation rate was reduced from 11.7% in the PA group to 4.6% in the PSPA group (p<0.001) yielding a RR of 2.8 (CI 1.4;5.5). The reoperation rate due to PSPA was reduced from 7.4% to 3.2% (p=0.022) resulting in a RR of 2.4 (1.1;5.4), and the total surgery related complications were reduced from 15.2% to 6.7% (p<0.001) resulting in a RR of 2.8 (1.5;4.9).
Interpretation / Conclusion: PSPA in FFN patients treated with a HA was associated with a reduction in dislocations from 11.7% to 4.6%. This approach could easily be introduced and in the authors’ opinion, the approach has the potential to lower the dislocation rate even further by sparing all structures posteriorly.

2. Prediction of 30-day mortality in patients undergoing hip fracture surgery: the impact of surgery delay.
Thomas J. Hjelholt¹, Bjarke L. Viberg², Henrik Palm³, Morten T. Kristensen4, Niels Dieter Röck², Alma B. Pedersen¹
¹Department of Clinical Epidemiology, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark. ²Department of Orthopaedic Surgery and Traumatology, Odense University Hospital ³Department of Orthopaedic Surgery, Copenhagen University Hospital, Bispebjerg and Frederiksberg, University of Copenhagen, Copenhagen, Denmark 4Department of Physical and Occupational Therapy, Copenhagen University Hospital, Bispebjerg-Frederiksberg and Department of Clinical Medicine, University of Copenhagen

Background: Thirty-day mortality following hip fracture surgery in Denmark is 10% on average. However, previously published studies indicate substantial variation depending on patient characteristics.
Aim: To evaluate the impact of surgery delay on the 30- day mortality risk, considering other important patient characteristics.
Materials and Methods: We identified all patients with a first-time hip fracture in 2011-2017 (N=28,791) from the population-based Danish Multidisciplinary Hip Fracture Registry. We used a previously published model for 1-year mortality on the same cohort, including the following patient-related predictors as explanatory variables: nursing home residency, comorbidity, pre-fracture basic mobility, BMI, and age. Subsequently, we stratified patients according to surgery delay from admittance (>6 hours, >12 hours, >18 hours, >24 hours and >36 hours). Outcome was death within 30 days from surgery. Using the logistic regression model, we predicted the absolute risk of death within 30 days based on all possible combinations of the included predictors.
Results: Depending on patient characteristics, predicted 30- day mortality spanned from 1% to 81%. We observed no clear variation in mortality across strata of surgery delay. E.g. patients aged 80-85 years admitted from own home waiting <12 hours for surgery had mortality ranging from 3% to 30% depending on levels of comorbidity, mobility, and body mass index. Corresponding numbers in patients waiting >12 hours were 3% - 28%. For the same patients waiting <18 hours, mortality ranged from 3% to 28%, whereas for those waiting >18 hours mortality ranged from 2% to 28%. For patients aged 65-70 years admitted from own, mortality varied from 1% to 14% and from 1% to 15% if waiting <12 and >12 hours, respectively.
Interpretation / Conclusion: Thirty-day mortality vary greatly depending on patient characteristics, but our data does not indicate that surgery delay impact mortality substantially. Selection of patients for early surgery based on factors not included in the model could, however, explain the apparently missing effect of surgery delay on 30-day mortality.

3. The majority of community-dwelling hip fracture patients return to independent living with minor increase in care needs
Christina Frølich Frandsen ¹ ², Maiken Stilling ¹ ² ³, Eva Natalia Glassou ¹ 4, Torben Bæk Hansen ¹ ²
University Clinic for Hand, Hip and Knee Surgery, Department of Orthopaedics, Gødstrup Hospital, Denmark ¹ Department of Clinical Medicine, Aarhus University, Denmark ² Department of Orthopaedics, Aarhus University Hospital, Aarhus, Denmark ³ Department of Quality, Gødstrup Hospital, Denmark 4

Background: Hip fracture patients are fragile, and the majority fail to fully recover to their pre-fracture functional level, resulting in an increase in institutionalization.
Aim: The study aimed to investigate risk factors for poor short-term functional recovery and failure to return to independent living 12 months after a hip fracture.
Materials and Methods: From 2011 and through 2017, all surgically treated hip fracture patients admitted from their own homes were included in a prospective cohort study. Patient characteristics, comorbidities, surgical method, and mobilization during the hospital stay were registered. Short- term functional recovery was measured at discharge using a cumulated ambulatory score (CAS). At 12 months, patients were interviewed regarding residence, regaining function, and care needs. Multivariable logistic regression was used, reporting odds ratio (OR) with 95% confidence intervals (95%CI).
Results: 2,006 patients had data regarding their hospital stay and were included in the analyses for short- term functional recovery. 1,342 patients were interviewed at 12 months and used in the analyses for failure to return to independent living. Modifiable variables associated with poor short- term functional recovery (CAS<6) were hypoalbuminemia, not mobilized to standing within 24 hours, and length of stay. Failure to return to independent living at 12 months was found in 10% of the patients and was primarily associated with patient characteristics and comorbidities, but also poor short-term functional recovery (CAS<6). However, few reported increased care needs of those returning to independent living.
Interpretation / Conclusion: The risk factors associated with poor short-term functional recovery were primarily static. However, mobilizing patients to standing within 24 hours from hip fracture surgery is modifiable and found to be associated with short-term functional recovery. The present study found that failure to return to independent living at 12 months is seen in the frailest patients. However, the majority remains in their own home with only a slight increase in care needs.

4. A multilevel approach for evaluating hospital variation in red blood cell transfusion after hip fracture surgery in a population-based cohort study
Pia Kjær Kristensen1, Nickolaj Risbo2, Pedersen Alma Becic2
1) Department of Ortopaedics, Aarhus University hospital 2) Department of Clinical Epidemiology, Aarhus University hospital

Background: Surgery for hip fractures frequently requires red blood cell (RBC) transfusion in order to treat pre-existing and acute acquired anemia and operative bleeding. Postoperative anemia in hip fracture patients is associated with reduced rehabilitation and functional independence, as well as increased mortality. However, the indications for RBC transfusion in elderly with hip fractures had not been standardized.
Aim: To examine the variation in use of RBC transfusion within seven days after hip fracture surgery across 21 orthopaedic departments in Denmark.
Materials and Methods: In this nationwide population-based cohort study, patients who underwent surgery for an incident hip fracture in 2016 and 2017 (n=11,372) were identified in the Danish Multidisciplinary Hip Fracture Registry. Data on RBC transfusion were obtained from the Danish Transfusion Database. Prevalence of RBC transfusion was defined as transfusion within 7 days after surgery (yes/no). We used a stepwise multilevel logistic regression analysis to investigate predictors of variation adjusting for sociodemographic, fracture type, Charlson Comorbidity Index, type of surgery and prescriptions of anticoagulants, steroids, and NSAIDs. The variation between hospitals was examined using the Intra Class Coefficient (ICC).
Results: The overall prevalence of RBC transfusion was 32.9 %. The adjusted prevalence of RBC transfusion varied from 16.0% to 73.1%. A pertrochanteric fracture (Odds Ratio (OR)= 7.14 95% Confidence Intervals (CI) (5.96-8.54), high sociodemographic score (OR=3.15 CI(2.77- 3.59) and pre-fracture use of anticoagulants (OR=1.31 CI(1.19-1.44) were predictors of higher risk of RBC transfusion. The ICC indicated that 8.8% of the adjusted variance was due to hospital differences.
Interpretation / Conclusion: Substantial variation in use of RBC transfusion within 7 days after hip fracture surgery among departments exists. The major part of the variation is explained by patient-related factors such as fracture type, sociodemographics and use of anticoagulants. One tenth of the variation is related to systematic differences between hospitals. Further analyses are needed to examine the impact of hospital-level variation on the prognosis of hip fracture patients.

5. Geographic variation in hip fracture incidence and care-processes: a comparison between Ireland and Denmark
Mary Walsh1, Jan Sørensen2, Cathrine Blake1, Søren Paaske Johnsen3, Pia Kjær Kristensen4
1: UCD School of Public Health, Physiotherapy and Sport Science, Health Science Centre Dublin 2: Healthcare outcome Research Centre, Dublin 3: Danish Centre for Danish Health Service Research, Aalborg University Hospital 4: Department of Orthopaedics Surgery, Aarhus University Hospital

Background: Large variations have been found in quality of care received after hip fracture. Ireland and Denmark both have established hip fracture audits that drive quality improvement nationally. Comparisons between the countries would allow for international benchmarking of practice.
Aim: To explore geographic variation of care quality in Ireland and Denmark
Materials and Methods: Patients aged =65 years treated surgically for hip fracture in Ireland from 2017 to 2020 and in Denmark from 2016 to 2017 were included from the Irish Hip Fracture Database (n=12,904) and the Danish Multidisciplinary Hip Fracture Registry (n=12,924). The rate of hip fracture surgery per 1,000 older persons (>64 years) and the proportion of patients achieving 14 care indicators was calculated with 95% confidence intervals, standardized for age- group and sex against denominators from the Irish census (2016) and dataset. Geographic variation was explored based on hospital area (5 regions in Denmark, 6 Hospital Groups in Ireland). Systematic Components of Variation (SCV) were calculated for each indicator and country.
Results: The average annual standardized incidence of hip fracture surgery per 1,000 older population was 4.7 in Ireland and 5.7 in Denmark. There were notably different patterns of intracapsular fracture repair (Hemiarthroplasty: Ireland=85%, Denmark=52%) and very high variation for total hip arthroplasties (THA) in both countries (SCV Ireland=10.6, Denmark=97.9). Ireland achieved lower rates of surgery within 36 hours (59% versus 84%), nutritional assessment (27% versus 84%), and pre-discharge mobility recording (52% versus 92%), with latter measures showing high within-country variation (SCV=19 and 25, respectively). Ireland showed longer hospital stays (median 12 versus 7 days), but lower 7-day (1.0% versus 3.1%) and 14-day (2.0% versus 5.5%) mortality.
Interpretation / Conclusion: Ireland and Denmark have similar hip fracture incidence, but different patterns of intracapsular fracture repair. Ireland should improve care in relation to early surgery, mobility, and nutrition assessment. Between-country differences in length of stay, THA provision and mortality require further investigation.

6. Orthogeriatric home visit is associated with overall reduced 30-day readmission following surgical treatment in +65-year-old patients with hip fracture
Thomas Giver Jensen¹, Martin Aasbrenn², Morten Tange Kristensen³, Troels Haxholdt Lunn4, Eckart Pressel², Henrik Palm¹, Charlotte Suetta², Søren Overgaard¹, Anette Ekmann²
Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg and Frederiksberg, Denmark¹; Geriatric Research Unit, Department of Geriatrics, Copenhagen University Hospital Bispebjerg and Frederiksberg, Denmark²; Department of Physio & Ergotherapy, Copenhagen University Hospital Bispebjerg and Frederiksberg, Denmark³; Department of Anaesthesia and Intensive Care, Copenhagen University Hospital Bispebjerg and Frederiksberg, Denmark4;

Background: High readmission rates are commonly seen in patients with hip fracture. However, evidence indicates that multidisciplinary home visits after hip fracture may improve care and reduce overall readmission rate.
Aim: We investigated whether an orthogeriatric home visit was associated with overall 30-day readmission in +65-year-old patients surgically treated for hip fracture.
Materials and Methods: We compared two year-cohorts separated by one year. Thus, 246 patients aged +65-year admitted with hip fracture between 13th June 2020 – 12th June 2021, discharged to own home or care facilities, and visited =1 were characterized as exposed and compared with a comparable but non-visited/non-exposed historical control cohort of 247 patients admitted between 1st January – 31st December 2018 . The orthogeriatric team consisted of an orthopaedic nurse specialist visiting the patients, preferably at day two and nine after discharge, and a hospital based geriatric medical specialist cooperating observations, treatment, and care decisions. Data were extracted form hospital medical records. Outcome was overall 30-day readmission defined as =12h length of stay, regardless of reason or place, within the first 30 days after discharge. Covariates included demographic, mental and physical functioning, medication, co-morbidity, severe complication, and residential status. Cox Regression models were used for analysis.
Results: The readmittance rate was reduced from 27% to 19% (p=0.03). Crude and fully adjusted Hazard Ratio in patients visited were 0.67 (CI95%: 0.46- 0.97) and 0.58 (CI95%: 0.39-0.85) compared with non-visited patients, respectively.
Interpretation / Conclusion: An orthogeriatric team visiting older discharged patients with hip fracture seems to be associated with overall reduced 30-day readmission.

7. Alcohol and drug use in patients younger that 60 years with hip fracture measured by validated instruments and the clinical eye
Sara Svanholm, Sebastian Strøm Rönnquist, Åsa Magnusson, Bjarke Viberg, Morten Tange Kristensen, Henrik Palm, Søren Overgaard, Cecilia Rogmark
Research Unit of Copenhagen University Hospital, Bispebjerg, Department of Orthopaedic Surgery and Traumatology; Department of Orthopaedics Lund University, Skåne University Hospital Malmö Sweden; Institute for Clinical Neuroscience, Karolinska Institute, Sweden; Department of Orthopaedic Surgery and Traumatology Lillebælt Kolding Hospital; Department of Clinical Medicine, Faculty of Health and Medical Sciences University of Copenhagen; Departments of Physiotherapy and Orthopedic Surgery, Copenhagen; University Hospital – Amager and Hvidovre, Hvidovre, Denmark; Department of Physical and Occupational Therapy, Copenhagen University Hospital – Bispebjerg and Frederiksberg & Department of Clinical Medicine, University of Copenhagen, Copenhagen Department of Orthopaedic Surgery and Traumatology, University Hospital Bispebjerg

Background: It is a common preconception that young individuals suffering hip fracture have alcohol- and/or substance use disorder (AUD/SUD). It is important to evaluate this for planning the rehabilitation, but previous studies have neither used validated questionnaires, nor investigated if the standard screening methods are sufficient.
Aim: The main objective was to describe the alcohol and drug consumption in adult hip fracture patients under 60 years using the validated AUDIT (Alcohol use disorder test) and DUDIT (Drug use disorder test) scores. We also investigated the correlation between the instruments and the physicians’ standard reporting of usage.
Materials and Methods: This is a sub-study of 90 women (W) and 126 men (M) from a multicenter cohort study of patients with a non-pathological, acute hip fracture treated at 4 hospitals in Denmark and Sweden. To map alcohol and drug use AUDIT and DUDIT forms were filled in. In addition, the researchers made an evaluation of the patients’ alcohol and drug use based on direct patient contact and medical chart information. AUDIT ranges 0-40 with 6 (W) and 8 (M) as the cut-off for hazardous/harmful use. DUDIT ranges 0-44 with a corresponding cut-off of 2 (W) and 6 (M).
Results: According to AUDIT scores, 19/76 W (25%) and 37/118 M (31%) had hazardous/harmful alcohol use. The clinical evaluation identified 23/90 W (25%) and 33/126 M (26%) to have AUD. The DUDIT scores equaled SUD in 4/79 W (5%) and 11/111 M (10%). The clinical evaluation depicted 4/90 W (4%) and 13/126 M (10%) to have SUD. There was a discrepancy between AUDIT/DUDIT and the “clinical eye”. 8 W and 13 M alcohol use remained undetected by the clinical evaluation, even if they had AUDIT scores indicating hazardous/harmful use. Also, 4 W and 4 M with DUDIT indicating SUD were overlooked by clinical evaluation.
Interpretation / Conclusion: AUD and SUD were more common than what is reported from the general population. Still, “only” one fourth had AUD, hence gainsaying the belief that most hip fractures in adult life are caused by hazardous alcohol/drug use. Clinicians must be aware that the two screening methods do not identify the same individuals, and further investigation in clinical practice is needed.

8. How to spot osteonecrosis of the femoral head after internal fixation of femoral neck fractures in younger patients, with implants in situ? Conventional x-ray versus MARS-MRI.
Maria L Jönsson*, Mikael Kindt*, Trine Torfing, Sebastian Strøm Rönnquist, Bjarke Viberg, Søren Overgaard, Cecilia Rogmark
Department of Orthopaedic Surgery and Traumatology, Copenhagen University Hospital, Bispebjerg; Department of Orthopaedics, Lund University, Skåne University Hospital, Malmö; Department of Radiology, Odense University Hospital, Odense; Department of Orthopaedics, Lund University, Skåne University Hospital, Malmö and Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense; Department of Orthopaedic Surgery and Traumatology, Copenhagen University Hospital, Bispebjerg and Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen; Department of Orthopaedics, Lund University, Skåne University Hospital, Malmö * Maria Jönsson and Mikael Kindt shares first authorship and have contributed equally to the article

Background: Osteonecrosis of the femoral head (ONFH) is a well-known complication after internal fixation of femoral neck fractures (FNF). Previous literature is inapplicable on the use of metal artifact reduction sequence (MARS) MRI, to diagnose post-traumatic ONFH with conventional metal implants present.
Aim: Our primary aim was to compare MARS MRI with conventional x-ray in diagnosing ONFH following internal fixation of FNFs, with implants in situ. Secondarily, we wanted to determine if signs of ONFH on MARS MRI correlates to patient reported outcomes (PROs) via Oxford Hip Score (OHS), and pain (visual analog scale (VAS)).
Materials and Methods: Between 2015-2018, 30 out of 44 adults under 60 years treated with internal fixation after FNF at Odense University Hospital or Skåne University Hospital, Malmö, were included in a prospective study. They were followed with x- rays and PROs at 4 months, 1 and 2 years while MARS MRIs were at 4 months and 1 year. OHS <34 and/or VAS pain score >20 mm was considered clinically relevant unfavorable outcome.
Results: At 1 year, 14 patients had a pathological MRI. 3 of them had ONFH on x-ray at 1 year, increasing to 5 at 2 years. 5/14 had unfavorable PROs. In the 5 patients with ONFH signs on both MRI and x-ray, 2 had unfavorable PROs. 10 patients had all normal MRIs, all of them had normal x-rays. 1/10 had unfavorable PROs at 2 year. 5 patients had inconsistent MRI results, of which 1 developed ONFH. 1 patient dropped out.
Interpretation / Conclusion: A normal MRI signals uneventful healing. In our cohort, information from a pathological MRI was not useful, as a majority remains free from radiological ONFH and symptoms. Furthermore, PROs did not correlate with imaging result. The findings from MRI MARS have to be better understood before taken into clinical practice.

9. Frailty is Associated with Increased Mortality and Re-admission in Geriatric Hip Fractures
Sagona Abigail, Ortega Carlos, Wang Liqin, Yeung Caleb, Selzer Faith, Zhou Li, von Keudell Arvind
Department of Orthopedic Surgery, Brigham and Women's Hospital Department of Internal Medicine, Brigham and Women's Hospital

Background: Frailty index (FI) is a tool used to help clinicians determine how well a patient may do after orthopedic trauma surgery. We evaluated the association between FI and both mortality and hospital re-admission in 316 patients who underwent surgery for a femoral neck or an intertrochanteric hip fracture. Our data suggests that FI stratification can help to identify a sub-set of patients at high risk for adverse outcomes following hip fracture. Our preliminary analyses appear to suggest that it may be a stronger risk factor of mortality than age alone.
Materials and Methods: We identified patients who were =65 years old, underwent surgical repair of a femoral neck or intertrochanteric hip fracture, co-managed by the orthopedic trauma and geriatric services at BWH between May 2018 and August 2020. Demographic and clinical data were extracted from MGB’s EDW and verified by chart review. FI scores were categorized as: Non-Frail/Pre-Frail (FI <0.21, n=62), Frail (0.21=FI<0.45, n=185), and Severely Frail (FI > 0.45, n=69). One-year outcomes were calculated using Kaplan-Meier methods and compared using log-rank statistics.
Results: 316 patients with hip fractures who underwent surgical repair and had a frailty index score assigned were identified. At baseline the mean age was 83.8 (SD 7.9) years and the mean FI was 0.33 (SD 0.14). Patients were predominantly white 278 (88.0%) and female 221 (69.9%). Femoral neck fractures accounted for 129 (40.8%) of cases and intertrochanteric fractures accounted for 187 (59.2%) of cases. By one-year, freedom from readmission was 62.0%, 44.4%, and 25.8% (p=0.001) in the non/pre-frail, frail, and severely frail groups, respectively. One-year survival rates were 100%, 84.0%, and 51.2% (p<0.001) in the respective frailty groups.
Interpretation / Conclusion: In this analysis, we found that higher FI is associated with higher adverse outcomes at one-year. Specifically, freedom from hospital readmission and survival were associated with better frailty categories. Further analyses will evaluate the role of age itself in relation adverse outcomes following repair of hip fractures. Our findings suggest that FI has a role in identifying high risk surgical candidates and may help guide clinical decision making.

10. Active clinical issues at discharge predict readmission within 30 days and one year following hip fracture surgery
Christina Frølich Frandsen ¹ ², Maiken Stilling ¹ ² ³, Eva Natalia Glassou ¹ 4, Anne Birgitte Langsted Pedersen 5, Torben Bæk Hansen ¹ ²
University Clinic for Hand, Hip and Knee Surgery, Department of Orthopaedics, Gødstrup Hospital, Denmark ¹ Department of Clinical Medicine, Aarhus University, Denmark ² Department of Orthopaedics, Aarhus University Hospital, Aarhus, Denmark ³ Department of Quality, Gødstrup Hospital, Denmark 4 Department of Medicine, Gødstrup Hospital, Denmark 5

Background: Early readmission to the hospital may be seen as a preventable failure to ensure safe discharge following a hip fracture. Premature discharge may be evaluated based on vital signs at discharge and medical complications during the hospital stay collectively called active clinical issues (ACIs), which have received little attention. Furthermore, time to surgery’s association to readmission have been investigated with conflicting results, however, none have investigated the impact of the reasoning for delaying surgery which may explain the inconsistent findings. There is a need for knowledge regarding such modifiable risk factors to prevent readmissions.
Aim: To explore any association between 1) medical issues that delay surgery and 2) ACIs at the time of discharge and 30-day readmission.
Materials and Methods: A consecutive cohort of hip fracture patients surgically treated from 2011 to 2017 had data collected prospectively during their hospital stay and 1 year postoperatively. ACIs were defined as unstable vital signs or antibiotic treatment at discharge. Risk factors for readmission were analyzed as time-to-event data, in a multivariable analysis with death as a competing risk using the pseudo- value approach. The following variables were selected for adjustment: age, sex, residence, ASA score, cognitive status, and NMS. Differences in patient characteristics between groups were analyzed using the chi-squared test. The attributable fraction of readmission due to medical issues delaying surgery and ACIs was calculated.
Results: 2,510 patients were included, of whom 14% were readmitted within 30 days and 39% within one year after hip fracture surgery. The most frequent causes of readmission within 30 days were medical causes unrelated to the hip fracture. ACIs were associated with an increased risk of readmission, especially due to medical and infectious causes. ACIs attributed to 46% of readmissions for medical causes. Medical issues resulting in surgery delays exceeding > 24 hours did not increase the risk of readmission within 30 days.
Interpretation / Conclusion: Readmission following hip fracture surgery is high, but some may be prevented. Resolving ACIs before discharge may reduce readmissions following hip fracture surgery.