Session 2: Trauma

13. November
09:00 - 10:30
Lokale: Sal C
Chair: Mette Rosenstand & Arvind von Keudel

11. Two-year follow-up of the VOLCON randomized controlled trial investigating outcome of volar plating vs casting of unstable distal radius fractures in patients older than 65 years
Daniel Wæver1, Karen Larsen Romme1, Jan Duedal Rölfing2, Rikke Thorninger2
1. Department of Orthopaedics, Regional Hospital Randers; 2. Department of Orthopaedics, Aarhus University Hospital.

Background: The treatment of unstable distal radius fractures (DRF) in elderly has been debated in recent years. Several randomized controlled trials (RCTs) conclude similar functional outcomes in non-operative vs. operative treatment after 1 year. Long-term follow-up regarding post-traumatic osteoarthritis are lacking.
Aim: Primary: to compare post-traumatic osteoarthritis in non-operatively vs. operatively treated unstable DRF. Secondary: to compare functional outcome.
Materials and Methods: Two-year follow-up of a single-center, assessor-blinded RCT of unstable DRF. 50 patients: volar locking plate, 2 weeks casting and 3 weeks orthosis. 50 patients: 5 weeks casting. Primary outcome: radiological post-traumatic osteoarthritis according to Jupiter and Knirk was assessed after 5 weeks and 2 years. Secondary outcome: Quick-DASH, PRWHE, range of motion (ROM), grip strength, and pain at 2-year follow-up.
Results: Of the 100 patients included for the primary study, 60 were available for the 2-year follow-up (non-operative: 28, operative: 32). Between the 1- and 2-year follow-up, 25 patients were excluded (death: 5, lost to follow-up: 6, excluded due to other sickness: 14). We found a higher degree of post-traumatic osteoarthritis after 2 years. However, according to two-way ANOVA analysis time accounted for 25% (p<0.001), the subject for 47% (p=0.004), and treatment only for 0.3% (p=0.565) of total variation. We found no statistically significant difference between groups regarding Quick-DASH, PRWHE, ROM, grip strength or pain.
Interpretation / Conclusion: The degree of post-traumatic osteoarthritis and functional outcome was similar between non-operatively and operatively treated unstable DRF in patients >65 years after 2 years.

12. Psychiatric diseases increase the risk of mortality and reoperation among hip fracture patients: a population-based study
Simon Storgaard Jensen1, Per Hviid Gundtoft2, Jan-Erik Gjertsen3, Alma B. Pedersen1
1. Department of Clinical Epidemiology, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark. 2. Department of Orthopedic Surgery, Traumatology, Aarhus University Hospital. 3. Department of Orthopedic Surgery, Haukeland University Hospital, Norway. Department of Clinical Medicine, University of Bergen, Norway.

Background: Reoperation is a common complication following hip fracture surgery. Despite the rising burden of psychiatric diseases worldwide, these patients are often excluded or deprioritized in studies. Hence, the impact of these diseases on mortality and the risk of reoperation remains unclear.
Aim: To examine mortality and the risk of reoperation after hip fracture surgery, comparing patients with or without psychiatric diseases.
Materials and Methods: Patients undergoing surgery for their first hip fracture were identified in the Danish Multidisciplinary Hip Fracture Registry. The history of psychiatric diseases was collected using diagnose codes in the Danish National Patient Registry for the 10-year period preceding index surgery. Reoperations were identified using surgical procedure codes from the Danish National Patient Registry. Reoperation was defined as any secondary surgical intervention on the same hip within one year of the index surgery. We calculated mortality risk and reoperation rate with 95% confidence intervals (CI), treating death as a competing risk.
Results: We included 110,625 hip fracture patients from 2004 to 2021, of which 15,254 (14%) had any psychiatric diseases. These patients had an increased one-year mortality rate of 35% (CI: 34-36) compared to 25% (CI: 24-25) for patients with non-psychiatric diseases. The reoperation rate within one year was 9.9% (CI: 9.5-10.4) for patients with psychiatric diseases compared to 10.3% (CI: 10.1-10.5) for patients without psychiatric diseases. The most common psychiatric diseases in the cohort were dementia, depression, neurotic disorders, and substance abuse, with reoperation rates of 8.1%, 12.3%, 14.4%, and 15%, respectively.
Interpretation / Conclusion: When compared to patients without psychiatric diseases, hip fracture patients with any psychiatric diseases had markedly increased mortality. Hip fracture patients with or without any psychiatric diseases have similar reoperation rates within one year. However, patients with a history of depression, neurotic disorders, or substance abuse had a higher reoperation rate. These findings underline the importance of targeted prevention strategies for these patients.

13. Time to mobilization in hours after surgery for hip fracture and 30-day mortality – A 6-year nationwide register study on 36,229 patients in Denmark
Morten Tange Kristensen1,2, Ina Trolle Andersen3,4, Alma Becic Pedersen3,4
1. Department of Physical and Occupational Therapy, Bispebjerg-Frederiksberg Hospital 2. Department of Clinical Medicine, University of Copenhagen 3. Department of Clinical Epidemiology, Aarhus University Hospital 4. Department of Clinical Medicine, Aarhus University

Background: Mobilisation within the first postoperative day is recommended for reducing 30-day mortality. However, no data are available on time in hours for mobilisation and hip fracture outcome.
Aim: We examined whether the time in hours for mobilization within the first 36 hours after surgery for a hip fracture was associated with 30-day post-surgery mortality.
Materials and Methods: 36,229 patients (67.3% women), 65 years or older undergoing surgery for a first-time hip fracture included in the Danish Multidisciplinary Hip Fracture Register from January 2016 through December 2021, were included. Exposure categories were time in hours to mobilisation (=6, >6-12, >12-18, >18- 24, >24-30 and >36 hours) from start of surgery. Outcome was mortality within 2-30 days of surgery (0.7% died before day 2). Time for mobilisation was missing for 4,401 patients of whom 16.3% died within 30 days. We calculated risks, risk differences (RD) and hazard ratios (HR) with 95%CIs using inverse probability of treatment weighted method to account for confounding; age, sex, surgery year, fracture type, time to surgery, residential status, BMI, pre-fracture mobility (CAS) and comorbidities.
Results: 30-day mortality risk for those mobilized =6 (n=1,503), >6-12 (n=4,509), >12-18 (n=8,351), >18-24 (n=12,730), >24-30 (n=2,636) >30-36 (n=254) and >36 (n=1,764) hours post-surgery were respectively 5.18% (4.13,6.39), 5.27% (4.65,5.94), 7.87% (7.30,8.46), 9.16% (8.66,9.67), 10.45% (9.32,11.66), 10.24% (6.89,14.34) and 15.83% (14.16,17.57). The RD and adjusted HR for 30-day mortality for those mobilized >24-36 versus =18 hours were respectively 2.26% (1.12, 3.40) and 1.33 (1.16,1.52). Comparing those mobilized >24-36 versus =24 hours, RD was 1.63 (0.51,2.76) and adjusted HR was 1.21 (1.07-1.37).
Interpretation / Conclusion: The risk of 30-day mortality increases with the increasing time in hours to mobilisation after surgery for a first-time hip fracture. Thus, we should aim for early mobilisation as soon as possible, not as < or > 24 hours post-fracture.

14. Impact of diabetes on the risk of subsequent fractures in 92,600 patients with an incident hip fracture: A Danish nationwide cohort study 2004-2018
Dennis Vinther1, Reimar W. Thomsen1, Ove Furnes2,3, Jan-Erik Gjertsen2,3, Alma B. Pedersen1
1. Department of Clinical Epidemiology, Department of Clinical Medicine, Aarhus University and Aarhus University Hospital, Aarhus, Denmark 2. The Norwegian Arthroplasty Register, Department of Orthopaedic Surgery, Haukeland University Hospital, Bergen, Norway. 3. Department of Clinical Medicine, University of Bergen, Bergen, Norway.

Background: Diabetes affects skeletal fragility and risk of hip fracture (HF).
Aim: We investigated the cumulative incidence rates of a subsequent HF and fractures other than HF after incident HF in patients with and without diabetes.
Materials and Methods: Using Danish medical databases, we identified 92,600 incident HF patients in the period 2004-2018. Diabetes was examined overall, by type of diabetes (T2D and T1D), and by presence of diabetes complications. We estimated cumulative incidences within two years of the incident HF. Using cause- specific Cox regression, adjusted hazard ratios (aHRs) with 95% confidence interval (CI) were calculated.
Results: Among incident HF patients, 11,469 (12%) had diabetes, of whom 10,253 (89%) had T2D and 1,216 (11%) had T1D. The 2-year incidence rates for a new subsequent HF were 4.8% (95% CI: 4.6-4.9) for patients without diabetes, 4.1% (CI: 3.8-4.6) for T2D, and 4.3% (3.3-5.6) for T1D. aHRs were 1.01 (0.90-1.14) for T2D and 1.17 (0.87-1.58) for T1D compared to patients without diabetes. There was effect modification by sex, as women with T1D had an aHR of 1.52 (1.09- 2.11) for subsequent HF, and by specific diabetes complications (for example, patients with T2D and prior hypoglycemic events had an aHR of 1.75 (1.24-2.42) for subsequent HF, while patients with T1D and neuropathy had an aHR of 1.73 (1.09-2.75), when compared with patients without diabetes). For fractures other than HF, the 2-year incidence rates were 7.3% (7.2-7.5) for patients without diabetes, 6.6% (6.1-7.1) for T2D, and 8.5% (7.0- 10.1) for T1D. aHRs were 1.01 (0.92-1.11) for T2D and 1.43 (1.16-1.78) for T1D compared to patients without diabetes. T2D was only a risk factor for fractures other than HF among HF patients of high age (age 86-89 years: aHR 1.22 (0.99-1.55), age 90+ years: aHR 1.37 (1.08- 1.74)), whereas T1D was robustly associated with increased risk of fractures other than HF in all subgroups.
Interpretation / Conclusion: Among HF patients, we found no strong overall association of T2D or T1D with increased risk of subsequent HF, but diabetes patients with prior hypoglycemic events or neuropathy were at increased risk. In contrast, patients with T1D had a clearly increased risk of subsequent fractures other than HF.

15. Interaction effect and excess risk of infection after hip fracture surgery in multimorbid patients: a nationwide registry-based cohort study of 92,599 patients
Cecilia Majlund Hansen1, Nadia Roldsgaard Gadgaard1, Christina M. J. E. Vandenbroucke-Grauls1,2, Nils P. Hailer3, Alma Becic Pedersen1
1. Department of Clinical Epidemiology, Aarhus University and Aarhus University Hospital, Denmark 2. Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, The Netherlands 3. Department of Surgical Sciences, Orthopedics, Uppsala University, Sweden

Background: Infection in general is a common and serious complication after hip fracture (HF) surgery, with pneumonia being the most frequent. Multimorbidity is highly prevalent in HF patients and is associated with elevated risk of infections. It is unclear whether multimorbidity interacts with HF to increase infection risk beyond their individual additive effects.
Aim: The aim of this study is to investigate the interaction effect between multimorbidity and HF surgery on the risk of any kind of post-surgical infection.
Materials and Methods: Using nationwide Danish registries, we identified 92,599 patients =65 years surgically treated for HF between 2004 and 2018. Matched on age and sex, a comparison cohort from the general population without HF (n=462,993) was randomly collected. Multimorbidity was defined using the Charlson Comorbidity Index in categories of no (score 0), moderate (score 1-2) or severe (score =3) multimorbidity. We computed incidence rates (IR) of any hospital-treated infection within 1 month and 1 year with 95% confidence intervals and estimated the interaction contrast based on the differences in IRs.
Results: The IR of infection within 1 month was 181 (176-186) per 100 person years in HF patients with no multimorbidity and 9 (95% CI 8-9) in the comparison cohort with no multimorbidity. The IRs were 240 (234-246) and 302 (291-313) in HF patients with moderate and severe multimorbidity compared with 17 (16-18) and 31 (30-33) in the comparison cohort with same multimorbidity level. Based on this, 21% and 33% of the IR within 1 month among HF patients with moderate and severe multimorbidity respectively was explained by interaction. Similar interaction was observed for 1 year follow-up.
Interpretation / Conclusion: Multimorbidity and HF surgery interact synergistically, which substantially increases the risk of infection. The interaction effect increased with multimorbidity level. Thus, multimorbid patients undergoing HF surgery are particularly vulnerable, and our findings highlight the potential benefits of implementing more targeted and personalized initiatives for multimorbid HF patients with aim of prevention, early detection, and early treatment of infections.

16. Socioeconomic position and infection risk after hip fracture surgery: a nationwide cohort study of 54,853 patients
Nadia R. Gadgaard1, Claus Varnum2,3, Rob Nelissen4, Christina Vandenbroucke-Grauls1,5, Henrik T. Sørensen1, Alma B. Pedersen1
1. Department of Clinical Epidemiology, Aarhus University Hospital and Aarhus University, Denmark; 2. Department of Orthopedic Surgery, Lillebaelt Hospital – Vejle, Denmark; 3. Department of Regional Health Research, University of Southern Denmark, Denmark; 4. Department of Orthopedics, Leiden University Medical Center, The Netherlands; 5. Department of Medical Microbiology and Infection Control, Amsterdam University Medical Center, Amsterdam, The Netherlands.

Background: Infections are among the most frequent and serious complications of hip fracture surgery.
Aim: To investigate the role of socioeconomic position (SEP) on infection risk, and markers of poor health or frailty as effect modifiers.
Materials and Methods: Individual-level data on SEP markers (education, liquid assets, marital status, and cohabitation) were obtained from Danish population-based medical registries for a cohort of hip fracture patients who underwent surgery between 2010-2018. The primary outcome was any hospital-treated infection within one month after surgery. We computed cumulative incidences and used Cox regression to estimate adjusted hazard ratios (aHRs) with 95% confidence intervals for the different SEP categories. Analyses were stratified on pre-fracture comorbidity clusters, body mass index (BMI), pre-fracture mobility, and residence type.
Results: The incidence of hospital-treated infection ranged between 15% and 19% for different SEP markers. All markers of low SEP were associated with increased risk of infection. For instance, the aHRs were 1.10 [1.02-1.18] among patients with low vs. high education, 1.21 [1.15-1.28] for low vs. high liquid assets, 1.24 [1.15-1.32] for divorced vs. married, and 1.16 [1.06-1.28] for living alone vs. cohabiting. Stratified analyses showed that incidence of infection was highest in the diabetic-renal comorbidity cluster, among underweight patients, those with poor mobility, or living in nursing home. Associations between markers of SEP and infections varied when stratified by comorbidity clusters, BMI, mobility, and residence type.
Interpretation / Conclusion: Not cohabiting, any unmarried status, low liquid assets, and low education were associated with 10% to 24% increased risk of infection within one month after hip fracture surgery. Comorbidity clusters, BMI, mobility, and residence type did modify the associations.

17. Is the Tip-Apex-Distance associated with the risk of reoperation after osteosynthesis with DHS in femoral neck fractures?
Jacob Schade Engbjerg1,2,4, Rune Dall Jensen2,4, Michael Tjørnild1, Rikke Thorninger3, Jan Duedal Rölfing2,3,4
1 Department of Orthopaedics, Regional Hospital Randers. 2 MidtSim, Central Denmark Region. 3 Dept. of Orthopaedics, Aarhus University Hospital. 4 Dept. of Clinical Medicine, HEALTH, Aarhus University

Background: Dynamic hip screw (DHS) fixation is a common surgical procedure for femoral neck fractures (FNF). Tip-apex distance (TAD), is a radiographic measurement used to assess the position of the screw in the femoral head. Studies suggest that a TAD > 25 mm is a risk factor for screw cut-out. Failure of the DHS (e.g. cut-out) often results in reoperation and is associated with prolonged pain and mobility.
Aim: This study investigates the association between TAD and postoperative complications following DHS osteosynthesis of FNF.
Materials and Methods: A retrospective review was conducted of all patients undergoing DHS treatment for FNF at Regional Hospital Randers between 2015 and 2021 (n=325). Patients were identified through Central Denmark Region’s Business Intelligence-portal using diagnosis code DS720. The primary outcome measure was a composite of complications identified on radiographs (cut- out, non-union, femoral head necrosis), reoperation, or death within one year. Radiographs were evaluated for TAD and postoperative complications / reoperations. Mann Whitney test was applied to assess the data.
Results: The overall complication and reoperation rate was 47 of 325 (14.5%) patients within 1 years, and 52 of 325 patients (16.0%) within 2 years. Mortality after 1 year was 16% and 26% after 2 years. The median TAD was 16.3 mm (IQR 13.8;18.7)), with no statistically significant difference (p = 0.56) between patients with and without complications < 1 year, TAD 16.3 mm (IQR 13.7;18.7) vs. 16.7 mm (IQR 14.1;19.2). No statistically significant difference was found between patients with and without complications < 2 years (p=0.99), TAD 16.3 mm (IQR 13.7;18.7) and 16.6 mm (IQR 14;18.5). Interestingly, there were 53/325 TAD > 20 mm and 6/325 TAD >25 mm in total.
Interpretation / Conclusion: We report no association between TAD and complication rates following DHS fixation for FNF. The relatively few TAD outliers did not result in an increased risk of complications.

18. Complication Rates and Additional Surgery Following Implementation of a New Clinical Guideline for the Treatment of Distal Radius Fractures in Adults
Jens-Christian Vedel1,2, Stig Brorson1,3, Dennis Winge Hallager 1,3
1. Center for Evidensbaseret Ortopædkirurgi Ortopædkirurgisk Afdeling, Sjællands Universitetshospital, Køge 2. Sjællands Universitetshospital, Nykøbing F 3. Institut for Klinisk Medicin Københavns Universitet

Background: Based on randomized trials comparing surgical procedures and implants for dorsally displaced distal radius fractures (DDDRF), Zealand University Hospital implemented a new evidence-based clinical guideline on August 1st, 2020. The guideline recommended closed reduction and percutaneous pinning (PP) as the primary treatment over open reduction and volar locking plate fixation (VLP), provided that acceptable reduction and stable fixation could be achieved with PP alone. Subsequently, the proportion of DDDRF cases treated surgically with VLP decreased from 100% to 44%, while PP increased from 0% to 56% in the year following guideline implementation.
Aim: This study aims to assess whether the increased use of PP over VLP was accompanied by increased complication rates and additional surgery.
Materials and Methods: Adult patients treated surgically for forearm fractures between January 1st, 2019, and December 31st, 2019 (group 1, pre-guideline implementation), and between August 1st, 2020, and July 31st, 2021 (group 2, post-guideline implementation), were screened for inclusion. Patients with DDDRF were included, while exclusion criteria encompassed high-energy or open fractures, prior fractures, concurrent fractures, neurovascular compromise, and patients reliant on walking aids or those who refused data use. The follow-up period extended from the fracture date until March 1st, 2024. Rates of complications and additional surgeries during the follow-up were compared between group 1 and group 2 using Pearson’s Chi- squared test.
Results: The analysis included 248 cases. Median follow-up was 57 months for group 1 and 36 months for group 2(p<0.001). In group 1, 13% (17 out of 136) experienced at least one complication compared to 6% (7 out of 112) in group 2 (p=0.10). Within the follow-up period, 13% (17 out of 136) of group 1 patients underwent secondary surgery compared to 8% (9 out of 112) in group 2 (p=0.3).
Interpretation / Conclusion: No statistically significant difference was observed in complication rates and additional surgery during the follow-up period before and after the practice change endorsing PP over VLP as the primary surgical approach for DDDRF.

19. Early mobilization following hip fracture surgery and subsequent risk of infection
Thomas Johannesson Hjelholt1, Ina Trolle Andersen2, Morten Tange Kristensen3, Alma Becic Pedersen2
1Department of Geriatrics, Aarhus University Hospital 2Department of Clinical Epidemiology, Aarhus University Hospital and Aarhus University 3Department of Physical and Occupational Therapy, Copenhagen University Hospital, Bispebjerg and Frederiksberg and Department of Clinical Medicine, University of Copenhagen

Background: Mobilization within the first day following hip fracture surgery is recommended as gold standard to reduce mortality and postoperative complications. However, an in-depth analysis of the association between early mobilization and risk of infection is lacking.
Aim: To evaluate the association between early mobilization and subsequent risk of infection.
Materials and Methods: Using the Danish Multidisciplinary Hip Fracture Registry, we included 36,229 patients aged 65 years or older undergoing surgery for hip fracture during 2016-2021. Within 2-30 days after surgery, we studied outcomes of any hospital-treated infection, pneumonia, urinary tract infection, and sepsis. Reoperation due to surgical-site infection was studied within 2-365 days. We calculated risks, risk differences (RD) and hazard ratios (HR) with 95% confidence intervals (CIs) using inverse probability of treatment weighted method to account for confounding.
Results: Overall, 27,174 (75%) patients were mobilized <24 hours, 2,890 (8%) were mobilized between 24-36 hours, and 6,165 were mobilized >36 hours of surgery or had no registration of mobilization time. Patients mobilized <24 vs 24-36 hours had similar characteristics. Risk of any infection was 12.9% (CI 11.7%-14.2%) in patients mobilized 24-36 hours of surgery and 10.9% (CI 10.5%-11.7%) in those mobilized <24 hours, corresponding to RD of 2.0% (CI 0.7-3.3) and HR of 1.2 (CI 1.1-1.3). Similar associations were observed for pneumonia, urinary tract infection, and reoperation, but not for sepsis.
Interpretation / Conclusion: Infection is a common complication after hip fracture surgery. Mobilization within 24 hours is clearly associated with reduced infection risk. Our results emphasize the importance of early mobilization and suggest a possible pathway for reducing infection risk thereby possibly reducing mortality.

20. Socioeconomic inequality in infection risk after hip fracture surgery: A nationwide temporal trend from 2010 to 2021
Nadia R. Gadgaard1, Claus Varnum2,3, Rob Nelissen4, Christina Vandenbroucke-Grauls1,5, Henrik T. Sørensen1, Alma B. Pedersen1
1. Department of Clinical Epidemiology, Aarhus University Hospital and Aarhus University, Denmark; 2. Department of Orthopedic Surgery, Lillebaelt Hospital – Vejle, Denmark; 3. Department of Regional Health Research, University of Southern Denmark, Denmark; 4. Department of Orthopedics, Leiden University Medical Center, The Netherlands; 5. Department of Medical Microbiology and Infection Control, Amsterdam University Medical Center, Amsterdam, The Netherlands.

Background: Lower socioeconomic position (SEP) is associated with elevated risk of infection after hip fracture surgery.
Aim: To examine whether socioeconomic inequality in infection risk decreased during 2010-2021.
Materials and Methods: Using Danish population-based registries, we identified 74,068 hip fracture patients and their data on SEP markers (education, liquid assets, marital status, living arrangements). We studied any hospital-treated infection and community- treated infection, within 30 days of surgery by four calendar periods. We computed cumulative incidences, and measured inequality over time by estimating adjusted hazard ratios, adjusted relative index of inequality, and adjusted slope index of inequality, all with 95% confidence intervals.
Results: Incidences of hospital-treated infection, ranging between 14% and 21%, and community-treated infection, ranging between 21% and 38%, were higher in patients with low vs high SEP, and increased during 2010- 2021 across all SEP markers. Inequality by education and by liquid assets for both outcomes remained unchanged over time. Inequality by marital status increased for both outcomes over time, while inequality by living arrangements increased for hospital-treated infections only indicating increasing gap in infection risk between unmarried and married patients, and between non-cohabitant or residential-care and cohabitant patients.
Interpretation / Conclusion: Educational and liquid assets inequality in 30- day infection risk after hip fracture surgery remained stable during 2010-2021, whereas an increase in inequality was observed by marital status and living arrangement. Our results indicate a growing health access gap between hip fracture patients with and without social support or those reliant on informal or residential care which could affect infection prevention and treatment.