Periprosthetic Distal Femur Fractures Research Articles

Early Complications of a Novel Retrograde Intramedullary Femoral Nail in the Treatment of Femur Fractures.

To determine the early implant failure rate of a novel retrograde intramedullary femoral nail. Retrospective cohort study. Academic level 1 trauma center. Patients aged 18 years and older with an acute OTA/AO 32-A, 32-B, 32-C, and 33-A fractures or periprosthetic distal femur fracture from April 2018 to April 2022 were included in the study. The 2 interventions compared were the Synthes Expert retrograde/antegrade femoral nail (or control implant) versus the next-generation retrograde femoral nail (RFN)-advanced retrograde femoral nail (RFNA or experimental implant) (Synthes, West Chester, PA). Early implant-related complications between the experimental and control implants were assessed including locking screw back out, screw breakage, intramedullary nail failure, need for secondary surgery, and loss of fracture reduction. Three hundred fourteen patients were identified with a mean age of 31.0 years, and 62.4% of the patients being male. Open fractures occurred in 32.5% of patients with 3.8% of injuries being distal femur periprosthetic fractures. Fifty-six patients were in the experimental group and 258 patients in the control group. Mean follow-up was 46.8 weeks for the control cohort and 21.0 weeks for the experimental cohort. Distal interlocking screw back out occurred in 23.2% (13 of 56) of the experimental group patients and 1.9% (5 of 258) of the control group patients ( P < 0.0001). Initial diagnosis of interlocking screw back out occurred at an average of 3.2 weeks postoperatively (range, 2-12 weeks). Fifty-four percent of patients who sustained screw back out underwent a secondary operation to remove the symptomatic screws (12.5% of all patients treated with the experimental implant required an unplanned secondary operation due to screw back out). A logistic regression model was used to predict screw back out and found the experimental implant group was 4.3 times as likely to experience distal locking screw back out compared with the control group ( P = 0.01). The retrograde femoral nail-advanced implant was associated with a significantly higher rate of screw back out with a substantial number of unplanned secondary surgeries compared with the previous generation of this implant. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Retrograde intramedullary nail fixation with oblique fixed angle screws versus locking plates in periprosthetic supracondylar fractures after total knee arthroplasty.

Common surgical procedures in the treatment of periprosthetic distal femur fractures (PPFF) include osteosynthesis with fixed angle locking plates (LP) and retrograde intramedullary nails (RIN). This study aimed to compare LPs to RINs with oblique fixed angle screws in terms of complications, radiographic results and functional outcome. 63 PPFF in 59 patients who underwent treatment in between 2009 and 2020 were included and retrospectively reviewed. The anatomic lateral and posterior distal femoral angle (aLDFA and aPDFA) were measured on post-surgery radiographs. The Fracture Mobility Score (FMS) pre- and post-surgery, information about perceived instability in the operated leg and the level of pain were obtained via a questionnaire and previous follow-up (FU) examinations in 30 patients (32 fractures). The collective (median age: 78years) included 22 fractures treated with a RIN and 41 fractures fixed with a LP. There was no difference in the occurrence of complications (median FU: 21.5months) however the rate of implant failures requiring an implant replacement was higher in fractures treated with a LP (p = 0.043). The aPDFA was greater in fractures treated with a RIN (p = 0.04). The functional outcome was comparable between both groups (median FU: 24.5months) with a lower outcome in the post-surgery FMS (p = < 0.001). Fractures treated with RIN resulted in an increased recurvation of the femur however the rate of complications and the functional outcome were comparable between the groups. The need for implant replacements following complications was higher in the LP group.

Total knee arthroplasty and periprosthetic distal femoral fracture: looking beyond the osteoporosis to previous osteoporotic fracture.

Osteoporosis is a risk factor for fractures, including those of the hip, vertebrae, and distal radius; however, the association between osteoporosis and periprosthetic fractures after total knee arthroplasty (TKA) has not been much investigated. Therefore, we aimed to investigate the association of the presence of systemic osteoporosis with periprosthetic fractures after TKA. This study included 34 patients with periprosthetic fractures following primary TKA and 106 controls matched for age and sex. Bone mineral density was evaluated at the femoral neck, total hip, and lumbar spine using dual X-ray absorptiometry. Medical records were reviewed for age; sex; body mass index; smoking; rheumatoid arthritis, endocrine diseases, and cardiovascular diseases; history of glucocorticoid use; medication for osteoporosis; and history of previous osteoporotic fracture. In addition, anterior femoral notching after TKA was evaluated. Univariable and multivariable logistic regression analysis were used to determine factors associated with periprosthetic fracture. The prevalence of osteoporosis in the fracture group was higher than that in the control group (61.8% vs. 40.6%, p=0.045). The rate of medication for osteoporosis was significantly low in the fracture group (47.6 % vs 76.7%, p=0.026). History of previous osteoporotic fracture (odds ratio [OR], 9.1; p=0.015) and osteoporosis (OR, 3.6; p=0.013) were significant risk factors for periprosthetic fractures after TKA. Medication for osteoporosis could decrease the risk of periprosthetic fracture (OR 0.3; p=0.020). Osteoporosis is a major risk factor for periprosthetic distal femoral fractures after TKA. Therefore, careful assessment and proper treatment of osteoporosis need and the importance of taking osteoporotic medication needs to be recognized to the patients following primary TKA, especially in patients with a history of osteoporotic fracture. Prognostic study, level III.

Clinical differences between periprosthetic and native distal femur fractures: a comparative observational study

IntroductionThe incidence of periprosthetic distal femur fractures (PDFF) is increasing as the number of total knee replacements becomes more common. This study compared the demographics, fracture characteristics, treatment, and outcomes of periprosthetic versus native distal femur fractures (NDFF).Materials and methodsThis was a retrospective cohort study of patients ≥ 18 who underwent surgical fixation of NDFF or PDFF from 2012 to 2020 at a level-1 trauma center. The main variables collected included demographics, AO/OTA fracture classification, fixation construct, concomitant fractures, polytrauma rates, bone density, and reduction quality. Primary outcomes were unexpected return to the operating room (UROR), hospital length of stay, and quality of reduction. T-tests, Fisher’s exact tests, and multivariate analyses were used for statistical analysis.Results209 patients were identified, including 70 PDFF and 139 NDFF. PDFF patients were elderly females (81%) with isolated (80%) and comminuted (85%) 33 A.3 (71%) fractures. NDFF patients included 53% females, were commonly middle-aged, and displayed comminuted (92%) 33 C.2 fractures. 48% of NDFF patients had concomitant fractures. Intramedullary nailing was the primary fixation for both groups, followed by nail-plate combination (37%) for PDFF and lateral locking plates (21%) for NDFF. NDFF patients experienced significantly longer hospital stays, higher UROR rates, and worse quality of reduction (p < 0.05). PDFF patients had a significantly greater prevalence of low bone density (p < 0.05).ConclusionPDFF occur as isolated injuries with significant metaphyseal comminution in elderly females with low bone quality. NDFF commonly occurs in younger patients with less metaphyseal comminution and concomitant fractures. Intramedullary nailing was the most common treatment for both groups, although preference for nail-plate combination fixation is increasing. NDFF type 33 C fractures are at greater risk of UROR.

FROM THE TOP TO THE BOTTOM: UTILITY OF THE NOTTINGHAM HIP FRACTURE SCORE IN PREDICTING DISTAL FEMUR FRAGILITY FRACTURE MORTALITY

The Nottingham Hip Fracture Score (NHFS) is validated to predict mortality after fragility neck of femur fractures (NOF). Risk stratification supports informed consent, peri-operative optimisation and case prioritisation.With the inclusion of fragility distal femur fractures (DFF) in the BPT, increasing attention is being placed on the outcome of these injuries. Developing on the lessons learnt over the past decades in NOF management is key.This study assesses the validity of the NHFS in predicting mortality after fragility DFFs.A multi-centre study of 3 high volume fragility fracture units was performed via a retrospective analysis of prospectively collected databases.Patients aged 60 years-of-age who presented with AO 33.A/B/C native DFF, or V.3.A/B periprosthetic DFF over an 86-month period between September 2014 and December 2021 and underwent surgical treatment were eligible for inclusion. Open and/or polytrauma (ISS &gt;15) were excluded.All operations were performed or supervised by Consultant Orthopaedic Surgeons and were reviewed peri-operatively by a 7-day MDT.Patients with a NHFS of gt;=5 were stratified into a high-risk of 30-day mortality cohort, with all others being œlow-risk.285 patients were eligible for inclusion with 92 considered to be low-risk of 30-day mortality, these tended to be younger female patients admitted from their own homes.30-day mortality was 0% in the low-risk cohort and 6.2% (12/193) in the high-risk group. 1-year mortality was 8.7% (8/92) and 35.7% (69/193) in the low and high-risk groups respectively.Area Under the Curve (AUC) analyses of Receiver Operator Characteristic (ROC) curves demonstrated the greatest ability to predict mortality at 30-days for the high-risk cohort (0.714).The NHFS demonstrates a good ability to predict 30-day mortality in those patients with a NHFS =5 after a surgically managed fragility DFF. With comparable mortality outcomes to those documented from fragility NOF.

Distal femoral replacement for the treatment of periprosthetic distal femoral fractures around a total knee arthroplasty: a meta-analysis.

Periprosthetic fracture is a rare complication of arthroplasty but can have devastating consequences for the patient and presents a complex surgical challenge. Locking compression plate and retrograde intramedullary nail are both widely accepted surgical fixation techniques for distal femoral periprosthetic fractures around a total knee arthroplasty. Although there is still a need for further high-quality research into both techniques, there is even less literature concerning the use of distal femoral replacement to treat distal femoral periprosthetic fractures. Interest has been piqued in distal femoral replacements for the treatment of distal femoral periprosthetic fractures due to the theoretical advantages of immediate post-operative weight-bearing and lack of dependence on fracture union, but there are still understandably reservations about performing such an extensive and invasive procedure when an accepted alternative is available. This meta-analysis aims to evaluate the current literature to compare the complication rates and return to pre-operative ambulatory status of distal femoral replacement and locking compression plate. A literature search was performed to identify articles related to the management of distal femoral periprosthetic fractures around a total knee arthroplasty in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Methodological quality was assessed using the methodological index for non-randomized studies (MINORS) criteria. Articles were reviewed, and data extracted for analysis. Five articles met the inclusion criteria, reporting on 345 periprosthetic fractures. The overall rates of complications for distal femoral replacement and locking compression plate were: re-operation (6.1% vs 12.1%), infection (3.0% vs 5.3%), mortality (19.7% vs 19.3%), and return to pre-operative ambulatory status (60.9% vs 71.8%) (respectively). This meta-analysis shows no statistically significant difference in the rates of re-operation, infection, mortality or return to pre-operative ambulatory status when comparing distal femoral replacement to locking compression plate.

Technique chirurgicale de reprise de prothèse totale de genou dans le cadre d’une fracture fémorale péri-prothétique

Treatment strategies for periprosthetic distal femoral fracture depend on the type of fracture, level with respect to the prosthesis, and prosthesis fixation. The usual treatment is internal fixation by nail or locking plate. This can be more difficult when the fracture is close to the joint, is destabilizing the prosthesis or is associated with reduced bone stock, and implant exchange should be considered, depending on the patient’s health status. The aim is to obtain the fastest possible recovery while limiting complications and minimizing surgery time for often frail and elderly patients. The present study details the implant revision technique in periprosthetic distal femoral fracture, which requires experience in traumatology and prosthetic revision and material adapted to the situation.Level of evidence: V, expert opinion

Finite element analysis of the stability of retrograde intramedullary nail and plate-screw combinations for periprosthetic femoral fractures following total knee replacement.

Periprosthetic fractures following total knee replacement are rare but challenging. The goal of the treatment is to achieve the most stable fixation that allows early mobilization. Therefore, the aim of this study was to evaluate the biomechanical results of the use of different fixation systems in the treatment of distal femur periprosthetic fractures with finite element analysis. A total knee prosthesis was implanted in Sawbone femur models. A transverse fracture line was created in the supracondylar region and was fixed in four different groups. In group 1, fracture line fixation was fixed using retrograde intramedullary nailing. In group 2, fixation was applied using a lateral anatomic distal femoral. In group 3, in addition to the fixation made in group 1, a lateral anatomic distal femoral plate was used. In group 4, in addition to the fixation made in group 2, a 3.5 mm Limited Contact Dynamic Compression Plate (LC-DCP) was applied medially. Computed Tomography (CT) scans were taken of the created models and were converted to three-dimensional models. Axial and rotational loading forces were applied to all the created models. The least deformation with axial loading was observed in the double plate group. Group 3 was determined to be more advantageous against rotational forces. The greatest movement in the fracture line was found in group 2. The application of the medial plate was determined to reduce the tension on the lateral plate and increase stability in the fracture line. Combining a lateral anatomic plate with intramedullary nailing or a medial plate was seen to be biomechanically more advantageous than using a lateral plate or intramedullary nailing alone in the treatment of distal femoral periprosthetic fractures.

Revision total knee arthroplasty with periprosthetic distal femoral fracture

Treatment strategies for periprosthetic distal femoral fracture depend on the type of fracture, level with respect to the prosthesis, and prosthesis fixation. The usual treatment is internal fixation by nail or locking plate. This can be more difficult when the fracture is close to the joint, is destabilizing the prosthesis or is associated with reduced bone stock, and implant exchange should be considered, depending on the patient's health status. The aim is to obtain the fastest possible recovery while limiting complications and minimizing surgery time for often frail and elderly patients. The present study details the implant revision technique in periprosthetic distal femoral fracture, which requires experience in traumatology and prosthetic revision and material adapted to the situation. Level of evidenceV, expert opinion.

Revision surgery for periprosthetic fracture of distal femur after endoprosthetic replacement of knee joint following resection of osteosarcoma.

Periprosthetic fracture (PPF) is one of the severe complications in patients with osteosarcoma and carries the risk of limb loss. This study describes the characteristics, treatment strategies, and outcomes of this complication. Patients were consecutively included who were treated at our institution between 2016 and 2020 with a PPF of distal femur. The treatment strategies included two types: 1) open reduction and internal fixation with plates and screws and 2) replacement with long-stem endoprosthesis and reinforcement with wire rope if necessary. A total of 11 patients (mean age 12.2 years (9-14)) were included, and the mean follow-up period was 36.5 (21-54) months. Most fractures were caused by direct or indirect trauma (n = 8), and others (n = 3) underwent PPF without obvious cause. The first type of treatment was performed on four patients, and the second type was performed on seven patients. The mean Musculoskeletal Tumor Society (MSTS) score was 20 (17-23). All patients recovered from the complication, and limb preservation could be achieved. PPF is a big challenge for musculoskeletal oncologists, particularly in younger patients. Additionally, PPF poses a challenge for orthopedic surgeons, as limb preservation should be an important goal. Hence, internal fixation with plates and endoprosthetic replacement are optional treatment strategies based on fracture type and patient needs.

Dual Plate Fixation of Periprosthetic Distal Femur Fractures.

Dual implants for distal femur periprosthetic fractures (DFPF) is a growing area of interest for these challenging fractures with dual plating (DP) emerging as a viable construct for these injuries. In the current study we review our experience with DP constructs. Retrospective case series with comparison group. Level 1 academic trauma centerPatients/Participants: Adults >50 years old sustaining comminuted OTA/AO 33-A2 or 33-A3 DFPF treated with either DP or a single distal femur locking plating (DFLP). Patients with simple 33-A1 fractures were excluded. Prior to 2018 patients underwent DFLP after which the treatment of choice at our institution became DP. 34 patients treated with DFLP and 38 with DP met inclusion and follow up criteria. The average patient age in the DFLP group was 74.8 +/- 7.3 years compared to 75.9 +/- 11.3 years in the DP group. Dual plating or single DFLP. Reoperation rate, alignment, and complications. Average follow up was 18.2 +/- 13.8 months in the DFLP group and 19.8 +/- 16.1 months in the DP group (p=0.339). There were no statistical differences in demographics, fracture morphology, loss of reduction, or reoperation for any cause (p>.05). However, DP patients were more likely to be weight bearing in the twelve-week postoperative period (p <0.001) and return to their baseline ambulatory status (p = 0.004) compared to DFLP patients. Dual plating of distal femoral periprosthetic fractures maintained coronal alignment with a low reoperation rate even with immediate weight bearing and these patients regained baseline level of ambulation more reliably as compared to patients treated with a single distal femoral locking plate.

Should megaprosthesis implants be a viable option in elderly patients after distal femur and periprosthetic distal femur fractures?-a retrospective cohort study.

Distal femur fractures (DFF) and periprosthetic distal femur fractures (PDFF) in elderly patients are challenging to manage, often requiring the use of distal femur replacement (DFR) implants to manage severe bone loss and comminution. The study's main purpose was to analyze outcomes and complications of DFR implant after DFF or PDFF at our institution to understand the feasibility and reliability of this treatment considering a review of the current literature. Fourteen consecutive patients undergoing total knee replacement with megaprosthesis implant from January 1st, 2017 to January 1st, 2021, at our institution were retrospectively analyzed. Inclusion criteria were age ≥65 years and DFF or PDFF after primary total knee arthroplasties (TKA) implantation. Patient-reported outcome measures (PROMs) such as Knee Society Score (KSS) and Oxford Knee Score (OKS) were analyzed, as well as radiographic pre- and post-operative imaging. Complications were recorded from the early postoperative period to the last follow-up. Nine patients were diagnosed with PDFF and five with DFF. At a mean follow-up of 30.7 months (range, 12 to 69 months), the mean KSS knee score was 79.5±11.2; the mean KSS function score was 69.0±17.9. The mean OKS was 31.6±8.9. The mean age at intervention was 82.1±7.6 years. Two delayed wound closures and one chronic prosthetic joint infection (PJI) were observed. No death was observed at the last follow-up. Megaprosthesis implants could be a suitable option in elderly, arthritic patients diagnosed with complicated DFFs and PDFFs, allowing joint function preservation and a rapid return to daily activities. DFR remains an intervention burdened by devastating complications that must be considered in the treatment choice.

Periprosthetic distal femoral fractures after total knee replacement treated by ORIF. Mid to long-term follow-up study in 12 patients.

Periprosthetic fractures following total knee arthroplasty are a quite uncommon traumatic lesion that often are present in elderly patients with osteoporosis and comorbidities. The most common periprosthetic fracture affects the distal femur. The main internal fixation techniques are ORIF with a locking plate and retrograde intramedullary nailing. In the present study, we report the medium-long term results in 12 patients with a distal femoral periprosthetic fracture stabilized with a locking plate. We reviewed 12 patients affected by a periprosthetic distal femur fracture surgically treated between 2010 and 2016 by ORIF using a locking compression plate after an average follow-up of 5.75 years. The average age of the patients at diagnosis was 78 years. The mean interval time between knee arthroplasty and distal femoral fracture was 8.25 years. Clinical results were assessed using the WOMAC score, while radiographic results according to Beals and Tower's criteria. All fractures of our series were type II according to the Rorabeck and Taylor classification. At follow-up, the WOMAC score ranged from 40.5 to 76.5 points (average 53.92). Radiographic results, according to Beals and Tower's criteria, were excellent in 5 patients and good in 7. All patients returned to their previous daily activities. We believe that reduction and internal fixation with a locking plate is a surgical option of treatment that provides satisfactory clinical and radiological results in Rorabeck type II periprosthetic distal femoral fractures.

Intramedullary Fibular Strut Allograft and a Small Fragment Nonlocking T-plate for Periprosthetic Lateral Femoral Condyle Fracture: A Case Report

Intramedullary Fibular Strut Allograft and a Small Fragment Nonlocking T-plate for Periprosthetic Lateral Femoral Condyle Fracture: A Case Report

High revision rates and mortality after distal femoral replacement for periprosthetic distal femoral fractures: analysis from the German Arthroplasty Registry (EPRD)

PurposeThis study was initiated to analyze the outcome after distal femoral replacement (DFR) for periprosthetic distal femoral fractures (PDFF).MethodsData from the German Arthroplasty Registry (EPRD) were analyzed. A total of 626 patients could be identified with a DFR for PDFF. Mean age was 78.8 years, and 84.2% were female. Revisions and mortality were analyzed and compared with patient groups with a similar procedure (revision total knee arthroplasty) or similar general condition (fracture total hip arthroplasty, hip hemiarthroplasty). Matched-pair-analyses were performed.ResultsWithin one year after surgery, 13.2% of the patients had died and further 9.4% were revised. Within four years, 32.7% had died and 19.7% were revised. Revisions were nearly twice as high as in the comparison groups. Periprosthetic infection (PJI) was the most frequent cause for revision, resulting in a PJI rate of 12.8%, which was lower in the comparison groups. Mortality after DFR was as similar high as after fracture hip arthroplasty.ConclusionPDFF are a serious injury, and the necessary surgical treatment has a high risk of complications. Every third patient after DFR for PDFF had died and every fifth patient needed revision within 4 years after surgery. Efforts should be undertaken to provide optimal treatment to these high-risk patients to reduce unfavorable outcomes.Level of evidenceIII.Registration of clinical trialsAs this is a registry-derived study of data of the German Arthroplasty Registry (EPRD), no registration was performed.

Supplemental fixation of distal femur fractures: a review of biomechanical and clinical evidence

Background: Fixation of distal femur fractures with lateral locking plates has relatively high rates of clinical failure. Supplemental fixation has shown promising results, and may reduce rates of fixation failure or nonunion. This review aimed to assess the biomechanical and clinical evidence regarding the use of supplemental fixation of distal femur fractures. Methods: PubMed, Embase, and Cochrane databases were searched for English language studies up to December 4, 2020, identifying 1,829 studies. Biomechanical studies that assessed fracture displacement, load/cycles to failure, or construct stiffness and clinical studies that assessed fixation failure or nonunion after supplemental fixation of distal femur fractures were included. Studies with sample size ≤5, ORIF with non-locking plates, periprosthetic distal femoral fractures, nonunions or revision surgeries were excluded. Results: Seventeen studies were included, of which 8 were biomechanical and 9 clinical. Overall, biomechanical studies demonstrated increased construct stability and load to failure with various supplemental fixation strategies. Clinical studies demonstrated more mixed outcomes for nonunion and fixation failure rate among the various techniques. Conclusions: Biomechanical studies have demonstrated potential benefits of these strategies, but there remains a dearth of high-quality evidence evaluating their effect on clinical outcomes. Prospective RCTs are necessary to address these issues and confirm the results in the existing literature. Level of Evidence: IID

Primary and Periprosthetic Distal Femur Fractures in Older Adults: No Difference in 12-Month Mortality and Patient-Reported Outcomes.

To compare fracture incidence, mortality, and patient-reported health outcomes at 6 and 12 months postinjury between primary and periprosthetic distal femur fractures in older adults. A registry-based cohort study was conducted including all adults 70 years of age or older registered by the Victorian Orthopaedic Trauma Outcomes Registry who experienced a primary or periprosthetic distal femur fracture between 2007 and 2017. Outcomes included mortality and health status (Three-Level European Quality of Life-Five Dimensions Scale [EQ-5D-3L]) collected at 6 and 12 months postinjury. All distal femur fractures were confirmed by radiological review. Multivariable logistic regression was conducted to report associations between fracture type and mortality and health status. A final cohort of 292 participants was identified. Overall mortality for the cohort was 29.8%, and no significant differences were found in mortality rate or EQ-5D-3L outcomes between fracture types (ie, primary vs. periprosthetic). A large proportion of participants reported problems across all EQ-5D-3L domains at 6 and 12 months postinjury, with slightly worse outcomes in the primary fracture group. This study reports high mortality and poor 12-month outcomes in an older adult cohort with both periprosthetic and primary distal femur fractures. Given these poor outcomes, fracture prevention and a greater focus on long-term rehabilitation is needed in this cohort. In addition, the involvement of an ortho-geriatrician should be considered as a routine component of care. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Outcomes of geriatric periprosthetic distal femur fractures: comparison of fixation versus reconstruction.

Comparing outcomes of periprosthetic distal femur fractures treated with open reduction internal fixation (ORIF) versus distal femoral replacement (DFR). Three major academic hospitals within one metropolitan area. Retrospective. 370 patients >64 years old with periprosthetic distal femur fractures were identified and 115 were included (65 ORIF vs 50 DFR). ORIF with locked plating versus DFR. One-year mortality, ambulatory status at 1 year, reoperations, and hospital readmissions. No differences were seen between ORIF and DFR cohorts with respect to demographics or medical history, including Charleston Comorbidity Index. DFR was associated with longer hospital stay (6.09 days ORIF vs 9.08 days DFR, p<0.001) and more frequent blood transfusion (12.3% ORIF vs 44.0% DFR, p<0.001). Logistic regression analysis using propensity score matching (PSM) demonstrated no statistically significant difference in reoperation, hospital readmission, ambulatory status at 1-year, or 1-year mortality between the two cohorts. Lastly, applying Bayesian model averaging using PSM to identify risk factors for 1-year mortality demonstrated that increasing age, length of index hospital stay, and 90-day hospital readmission were significantly associated with 1-year mortality, regardless of type of surgical treatment. Rehospitalization, reoperation, ambulatory status and 1-year mortality are no different between ORIF and DFR in the treatment of geriatric periprosthetic distal femur fractures when PSM is applied to mitigate selection bias. Further study is warranted to elucidate functional outcomes, long-term sequelae, and costs of care related to these treatment options to better guide treatment planning. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

CLINICAL DIFFERENCES AMONG PERIPROSTHETIC AND NATIVE DISTAL FEMUR FRACTURES

With an aging population and increase in total knee arthroplasty, periprosthetic distal femur fractures (PDFFs) have increased. The differences between these fractures and native distal femur fractures (NDFF) have not been comprehensively investigated. The purpose of this study was to compare the demographic, fracture, and treatment details of PDFFs compared to NDFFs.A retrospective study of patients ≥ 18 years old who underwent surgical treatment for either a NDFF or a PDFF from 2010 to 2020 at a level 1 trauma center was performed. Demographics, AO/OTA fracture classification, quality of reduction, fixation constructs, and unplanned revision reoperation were compared between PDFF patients and NDFF patients using t-test and Fisher's exact test. 209 patients were identified with 70 patients having a PDFF and 139 patients having a NDFF. Of note, 48% of NDFF had a concomitant fracture of the ipsilateral knee (14%) or tibial plateau (15%). The most common AO/OTA classification for PDFFs was 33A3.3 (71%). NDFFs had two main AO/OTA classifications of 33C2.2 (28%) or 33A3.2. (25%). When controlling for patient age, bone quality, fracture classification, and fixation, the PDFF group had increased revision reoperation rate compared to NDFF (P &lt; 0.05).PDFFs tend to occur in elderly patients with low bone quality, have complete metaphyseal comminution, and be isolated; whereas, NDFF tend to occur in younger patients, have less metaphyseal comminution, and be associated with other fractures. When controlling for variables, PDFF are at increased risk of unplanned revision reoperation. Surgeons should be aware of these increased risks in PDFFs and future research should focus on these unique fracture characteristics to improve outcomes.

How Often Do Complications and Mortality Occur After Operatively Treated Periprosthetic Proximal and Distal Femoral Fractures? A Register-based Study.

The incidence of periprosthetic femoral fractures is increasing because of an increasing number of primary THAs and TKAs. High rates of complications and mortality are associated with periprosthetic fractures, but few studies have evaluated and compared the population-based incidences of these events after fractures. (1) What is the annual incidence of periprosthetic fractures treated with surgery in one hospital district in Finland? (2) How are those incidences changing over time? (3) What is the risk of complications, reoperations, and death after those injuries? This register-based study evaluated 2259 patients who underwent revision THA or TKA or any surgery for a femoral fracture between January 2004 and December 2016 at the only hospital in our district where these types of operations are performed. During the study period, the diagnosis and operation codes of the operated-on patients varied greatly, and they were somewhat inaccurate. We thus evaluated radiographs of all 2259 patients one by one, and created inclusion and exclusion criteria based on radiologic findings and medical records. Of those, 12% (279 of 2259) had periprosthetic fractures that met the inclusion criteria, and from these, we formed two study groups (periprosthetic proximal femur fractures, n = 171; periprosthetic distal femur fractures, n = 108). Eighty-eight percent (1980 of 2259) of the patients were excluded because they were treated for a condition other than periprosthetic femoral fracture. The follow-up period ended in December 2019 or at the time the patient died. To evaluate the population-based incidence, we drew the number of individuals with THA or TKA in the hospital district from the Finnish Arthroplasty Register and the Finnish Hospital Discharge Register. The characteristics of patients with operatively treated periprosthetic femoral fractures were evaluated in terms of age, gender, fracture type, implant type, and time from the index operation to periprosthetic fracture. The annual incidences of periprosthetic femoral fractures are summarized per 1000 person-years of individuals living with an implanted THA or TKA and per 100,000 individuals per year living in our hospital district. The risks of death, complications, and reoperations were evaluated for both groups, and comparisons were made in terms of patient characteristics. The mean annual incidence of operatively treated periprosthetic proximal femur fractures per 1000 people living with THA implants was 2.3 ± 0.9 (95% confidence interval 1.8 to 2.7) per year, and for those with periprosthetic distal femur fractures with TKA implants, it was 1.3 ± 0.6 (95% CI 1.0 to 1.7). There was an increasing trend in the incidence of periprosthetic proximal femur fractures from 1.6 to 3.8 (95% CI 1.8 to 2.8) per 1000 arthroplasties, and it increased from 0.4 to 1.7 (95% CI 2.4 to 4.4) for periprosthetic distal femur fractures between 2004 and 2016. The mean population-based incidence of periprosthetic proximal femur fractures per 100,000 person-years was 5.3 ± 2.2 (95% CI 4.1 to 6.4) per year, and for periprosthetic distal femur fractures, it was 3.4 ± 1.7 (95% CI 2.5 to 4.4). The incidence of periprosthetic proximal femur fractures related to 100,000 person-years increased from 3.2 to 8.9 (95% CI 3.9 to 6.6), while the incidence of periprosthetic distal femur fractures increased from 1.3 to 4.4 (95% CI 2.4 to 4.8) during the study period. The cumulative incidence of major complications after periprosthetic proximal femur fracture was 8.8% at 1 year (95% CI 5.1% to 13.6%) and 12.3% at 10 years (95% CI 7.5% to 18.4%), and after periprosthetic distal femur fracture, it was 7.4% at 1 year (95% CI 3.5% to 13.4%) and 9.3% at 10 years (95% CI 4.7% to 15.7%). The cumulative incidence of reoperation after periprosthetic proximal femur fracture was 10.5% at 1 year (95% CI 6.5% to 15.7%) and 13.5% at 10 years (95% CI 8.9% to 19.1%), and for periprosthetic distal femur fracture, it was 8.3% at 1 year (95% CI 4.1% to 14.5%) and 13.8% at 10% years (95% CI 7.8% to 21.4%). The cumulative incidence of death after periprosthetic proximal femur fracture was 8.2% at 1 year (95% CI 4.7% to 12.9%) and 47.3% at 10 years (95% CI 38.1% to 55.9%), and after periprosthetic distal femur fractures, it was 14.8% at 1 year (95% CI 8.8% to 22.2%) and 67.8% at 10 years (95% CI 56.3% to 76.9%). The increased use of THA and TKA has led to an increase in the incidence of operatively treated periprosthetic fractures, which means there will be more revisions in the future. Older age, frailty of these patients, and often-complicated fracture patterns are related to a high rate of complications, reoperations, and mortality. Healthcare systems must prepare for a large increase in revisions for periprosthetic fracture, which are morbid events for patients and costly ones for healthcare systems. Level III, therapeutic study.