Incidence and outcomes of intraoperative periprosthetic acetabular fractures during cementless total hip arthroplasty: a prospective three-dimensional computer tomography-based study.

PURPOSE: Unlike periprosthetic femoral fractures, periprosthetic acetabular fractures during total hip arthroplasty (THA) have not been evaluated in detail. We prospectively evaluated the incidence, patterns, risk factors, and clinical outcomes of intraoperative periprosthetic acetabular fractures using pre- and postoperative computer tomography (CT). METHODS: In this prospective single-centre study, we evaluated 234 consecutive patients (250 hips) who underwent THA and three-dimensional CT before and after the surgery. We assessed the incidence, pattern of fractures, outcomes for each fracture pattern, reoperation and revision rates, Harris hip score, and visual analog scale (VAS) for pain. Multivariate regression models were used to identify risk factors for periprosthetic acetabular fractures. RESULTS: In total, 43 periprosthetic acetabular fractures (17.2%) were identified via CT. Fractures occurred most frequently at the superolateral wall. Early cup migration occurred in three hips. None of the patients underwent revision surgery for acetabular loosening. Regression modeling showed that rheumatoid arthritis was a significant predictor of periprosthetic acetabular fractures. CONCLUSIONS: Periprosthetic acetabular fractures are not infrequent during cementless THA and are more common in patients with rheumatoid arthritis.

Femoral revision in total hip arthroplasty using a cementless modular stem: clinical and radiological results with a 8-year follow-up.

INTRODUCTION: Modular femoral components allow for patient-specific restoration of hip joint geometry and the reconstruction of extensive bone defects in revision total hip arthroplasty (THA); however, potential problems of modular implants such as taper corrosion and the risk of implant fracture continue to be of concern. The aim of the present study was to evaluate the clinical and radiological results of a cementless modular revision stem following revision surgery due to aseptic loosening and periprosthetic fracture and to assess patient-reported outcome measures (PROMs) in these patients at mid-term follow-up. MATERIALS AND METHODS: In this study, a consecutive cohort of 75 patients who underwent primary revision THA at our institution using a modular cementless stem design (MRP-TITAN stem) was retrospectively evaluated at a mean follow-up of 7.7 years. Kaplan-Meier survivorship analyses were performed with revision of the femoral component for any reason as the end point. The Harris-Hip Score, the UCLA Activity Score, the Forgotten Joint Score and the SF-12 Score were used for clinical assessment. We used the Wilcoxon signed rank test to compare pre- and postoperative clinical scores. RESULTS: Overall stem survival with the endpoint stem re-revision for any reason was 85.4% at a mean follow-up of 7.7 years (range 2.4-14 years). Stem survival was 89.5% in the aseptic loosening group and 78.3% in the periprosthetic fracture group with no statistically significant difference between both groups (p = 0.107). One patient had to be revised due to taper fracture. PROMs improved significantly up to the latest follow-up, and radiographic evaluation showed full osseointegration of all stems in this cohort. CONCLUSIONS: Revision THA using a modular cementless titanium revision stem demonstrated adequate clinical and radiological results at mid- to long-term follow-up in this cohort. Cementless revision stems are a useful treatment option to restore the anatomy, especially in deformed hips and in complex revision hip arthroplasty. However, there are some significant disadvantages related to an increased risk of mechanical failure such as corrosion/fretting damage and implant fracture. Future high-quality prospective studies with longer follow-up are necessary to confirm the supposed advantages.

Ipsilateral pubic ramus fracture during total hip arthroplasty is not rare: does it matter?

INTRODUCTION: Periprosthetic fractures in total hip arthroplasty (THA) have been well described and studied. However, there is a lack of reports on ipsilateral pubic ramus fractures during THA due to the rare occurrence of such fractures and ambiguity of symptoms. With the use of postoperative computed tomography (CT) examinations, we have identified that asymptomatic ipsilateral pubic ramus fractures occur frequently during THA. This study aims to evaluate the incidence, location, clinical outcomes, and risk factors of ipsilateral pubic ramus fractures during THA. METHODS: From May 2022 to March 2023, a single surgeon performed 203 THAs in 183 patients at a single institution. All patients underwent postoperative CT scans three days after THA. The patients with ipsilateral pubic ramus fractures were followed up for a minimum of six months. Basic demographics, osteoporosis, general conditions of the operations, and outcomes of THA were investigated in all patients. RESULTS: Twenty-two cases (10.8%) of ipsilateral pubic ramus fractures were identified on postoperative CT scans. All fractures were located near the origin of the superior or inferior pubic ramus. Five fractures were detected on simple postoperative radiographs. The fractures did not cause any further complications at a minimum of six-month postoperative follow-up. Univariate and multivariate analyses did not identify any risk factors associated with these fractures. CONCLUSIONS: Although the incidence of ipsilateral pubic ramus fractures during THA is high, treatment is not required as they do not cause any significant clinical symptoms or affect the prognosis of THA. However, the possibility of occurrence of these fractures must be explained to the patients before surgery.

Locking plate for periprosthetic femoral fractures according to Vancouver C: Outcome and radiological subanalysis of 40 patients.

PURPOSE: Periprosthetic femoral fractures (PFF) according to type Vancouver C are less common and outcome is limited reported. Therefore, we conducted this retrospective single center study. METHODS: We performed analysis of patients who underwent open reduction and internal fixation (ORIF) with locking plates for PPF occurring distally of a primary standard hip stem. Data on demographics, revisions, fracture patterns, and mortality were evaluated. At least two years after operation, we examined outcome using the Parker and Palmer mobility score. Primary aim of this study was revision, outcome and mortality. Secondary aim was evaluation of fracture subtypes within type Vancouver C fractures. RESULTS: Between 2008 and 2020, 383 patients with periprosthetic femoral fracture after hip replacement were surgically treated according to our database. Among them, 40 patients (10.4%) with type Vancouver C fractures were enrolled for this study. The mean patient age was 81.5 years (59-94) at the time of fracture. Thirty-three patients were women, and 22 fractures were on the left side. Without exception, locking plates were used. The 1-year mortality rate for the sample was 27.5% (n = 11). Three revisions (7.5%) were performed for plate breakage. Rate of infection and non-union was zero. Three different fracture patterns were assessed: (1) transverse or oblique fractures below the tip of the stem (n = 9); (2) spiral-shaped fractures within the diaphysis (n = 19); and (3) burst fractures at the supracondylar region (n = 12). Demographic or outcome effects between fracture patterns were not found. On average of 4.2 years (2.0-10.4) after treatment, the mean reported Parker score was 5.5 (1-9). CONCLUSION: ORIF with a single lateral locking plate is safe for type Vancouver C fractures with a well-fixed hip stem. Therefore, we do not recommend routinely revision arthroplasty or orthogonal double plating. Three subtypes of fractures within Vancouver C demonstrated no significant differences in baseline data and outcome.

Perioperative periprosthetic femur fracture associated with direct anterior total hip arthroplasty using metaphyseal fit and fill stem.

INTRODUCTION: This study aims to identify radiographic and clinical risk factors of perioperative periprosthetic femur fracture associated with the direct anterior approach (DAA) using a metaphyseal fit and fill stem. We hypothesize stem malalignment with this femoral implant places increased stress on the medial calcar region, which leads to an increased risk of periprosthetic fracture. METHODS: We compared patients with periprosthetic femur fractures following DAA total hip arthroplasty (THA) utilizing the Echo Bi-Metric Microplasty Stem (Zimmer Biomet, Warsaw, IN) to a cohort of patients who did not sustain a periprosthetic fracture from five orthopedic surgeons over four years. Postoperative radiographs were evaluated for stem alignment, neck cut level, Dorr classification, and the presence of radiographic pannus. Univariate and logistic regression analyses were performed. Demographic and categorical variables were also analyzed. RESULTS: Fourteen hips sustained femur fractures, including nine Vancouver B2 and five AG fractures. Valgus stem malalignment, proud stems, extended offset, and patients with enlarged radiographic pannus reached statistical significance for increased fracture risk. Low femoral neck cut showed a trend toward statistical significance. CONCLUSION: Patients undergoing DAA THA using a metaphyseal fit and fill stem may be at increased risk of perioperative periprosthetic fracture when the femoral stem sits proudly in valgus malalignment with extended offset and when an enlarged pannus is seen radiographically. This study identifies a specific pattern in the Vancouver B2 fracture cohort with regard to injury mechanism, time of injury, and fracture pattern, which may be attributed to coronal malalignment of the implant.

Operative treatment of periprosthetic fractures of the proximal femur with a contralateral, upside-down LISS plate in elderly patients.

BACKGROUND: Increasing expectancy of life and levels of activity in the growing geriatric population lead to a rising number of prosthetic implants of the hip and consequently the incidence of periprosthetic fractures of the femur increase. The fracture pattern and the possible instability of the stem are a challenge to the orthopaedic surgeon. Treatment options are complete replacement of the implant or a solitary osteosynthesis. The goal of this study was to analyse the feasibility of the operative intervention using a contralateral reversed anatomic distal femoral LISS® locking plate and the radiological and functional outcome in a geriatric cohort. METHODS: We included all patients older than 75 years of age with a Vancouver type B fracture, which have been treated by osteosynthesis using a LISS® (contralateral reversed) plate in our institution in an interdisciplinary ortho-geriatric setting between 7/2013 and 12/2021. Perioperative morbidities, clinical and radiological outcome during follow-up were retrospectively analysed. RESULTS: During the observed time period, 83 patients (mean age: 88 years (range: 76-103), male/female: 26/57) were treated. Most fractures were Vancouver type B2 (n = 45, 54%) followed by B1 (n = 20, 24%) and B3 (n = 18, 22%). The most prevalent postoperative surgical complication was anaemia (n = 73, 88%) followed by infections (n = 12, 14%, urinary infections, pneumonia) and cardiovascular decompensation (n = 8, 10%). Clinical and radiological follow up 6-8 weeks postoperative was possible for 59 patients (70%). The majority of them did not describe pain (n = 50, 85%) and had a good or excellent radiological outcome. Three cases needed revision surgery due to infection and another three due to non-union, loosening of the stem or an additional fracture. 1-year mortality was 30%. CONCLUSION: We are convinced that the reversed contralateral LISS-plate is an easy-to-use implant with a small complication rate but a very successful and high healing rate in a geriatric, polymorbid cohort.

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

BACKGROUND: 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. QUESTIONS/PURPOSES: (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? METHODS: 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. RESULTS: 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%). CONCLUSION: 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 OF EVIDENCE: Level III, therapeutic study.

Long locking plate combined with locking attachment plate in patients with periprosthetic femoral fracture around ipsilateral stem after total knee arthroplasty.

BACKGROUND: The purpose of this study was to introduce the surgical technique using long locking plate and locking attachment plate (LAP) in patient with periprosthetic femoral fracture around ipsilateral stem after total knee arthroplasty (TKA). Moreover, we sought to investigate the outcomes of this fixation technique and to propose a new subtype in the existing classification of periprosthetic femoral fractures. METHODS: From January 2013 to January 2022, thirty-four consecutive periprosthetic femoral fractures around ipsilateral stem following TKA with minimum 1-year follow-up were enrolled in this study. Most cases were fixed with long-locking plate and LAP using the MIPO technique. For subgroup analysis, we classified patients with stemmed hip implant (group H) and stemmed knee implant (group K). Bone union, American Knee Society Score (AKSS) scale, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the Western Ontario and McMaster Universities Osteoarthritis Index for pain and function, and range of motion were investigated. RESULTS: The number of group H and K were 24 patients (70.6%) and 10 patients (29.4%), respectively. The mean age at operation was 71.5 years (range, 65‒85 years), and the mean follow-up period was 27.5 months (range, 12‒72 months). Bone union was confirmed radiographically in all patients, and the mean union time was 4.9 months (range, 3.5‒6 months). There were no significant differences in radiographic and clinical outcomes between the groups. CONCLUSIONS: Long-locking plate combined with LAP showed favorable radiographic and clinical outcomes in patients with periprosthetic femoral fracture around ipsilateral stem after TKA. LEVEL OF EVIDENCE: Level IV, Retrospective Case Series.

Vancouver type B2 periprosthetic femoral fractures: clinical and radiological outcomes from a tertiary care center.

INTRODUCTION: The purpose of this study was to report mid-term clinical and radiographic results after hip arthroplasty revision in Vancouver type B2 femoral periprosthetic fractures (PPFx). Specifical focus of the paper is as follows: (1) the description of a standardized and reproducible surgical technique, (2) functional outcomes presentation and (3) type and number of complications and implants' survival rate analysis. METHODS: We retrospectively reviewed all patients treated for hip revision with non-modular tapered fluted titanium stem in patients with Vancouver type B2 femur PPFx at a single institution. At least 18 months' follow-up period was required. Harris Hip Scores and SF-12 were obtained, and radiographical follow-up was performed. Complications were reported and analyzed. RESULTS: The authors included 114 patients (114 hips) with a mean follow-up of 62.8 ± 30.6 months. All patients were treated with Wagner SL revision hip stem (Zimmer-Biomet), metal cerclage wires ± trochanteric plate. The mean HHS and SF-12 score at the last follow-up evaluation were respectively 81.3 ± 9.7 and 32.5 ± 7.6. Seventeen (14.9%) complications occurred. We observed five cases of dislocations, two of periprosthetic joint infections and six cases of new PPFx. The stem-related revision rate for any cause at the final FU was 1.7%, due to PJI. No patients underwent stem revision surgery for aseptic loosening. Fracture healed in all the included patients with a union-rate of 100%. The re-operation rate for any cause was 9.6%, with an implant survival rate for overall failure of 96.5%. CONCLUSION: The presented standard and reproducible surgical technique obtains optimal clinical and radiological results with limited complication rate at mid-term follow up. Preoperative planning as well as careful intraoperative surgical technique is of a paramount importance.

Inadvertent, intraoperative, non- to minimally displaced periprosthetic humeral shaft fractures in RTSA do not affect the clinical and radiographic short-term outcome.

INTRODUCTION: Little information is available on the clinical and radiographic outcome of intraoperative, non- to minimally displaced humeral fractures that occur during implantation of a stemmed, reverse shoulder prosthesis but are only recognized on routine postoperative radiographs. The goal of this study is to report the clinical and radiographic outcome for this rarely reported fracture type. MATERIALS AND METHODS: 39 conservatively treated non- to minimally displaced intraoperative periprosthetic humeral fractures after stemmed RTSA were detected from our radiographic database between 1.1.2006 and 31.1.2018. Exclusion criteria were lack of patient consent, preoperative humeral fracture, and revision arthroplasties. Clinical (absolute and relative Constant score, the Subjective Shoulder Value) and radiographic (conventional radiographs) assessment was performed preoperatively, at 6 weeks (only radiographically) and at latest follow-up with a minimum follow-up of 2 years. RESULTS: 35 patient's with a mean age of 72 years (range 32-88, SD ± 11 years) and a mean follow-up of 53 months (range 24-124, SD ± 31) were included in the study. At latest follow-up, all clinical outcome parameters except external rotation improved significantly. A complication rate of 17% (n:6) was recorded. At 6 weeks after the index surgery, none of the radiographs showed a fracture displacement or a sintering of the stem. At latest follow-up, all fractures were healed and no stem loosening was observed in any of the shoulders. CONCLUSIONS: Non- to minimally displaced intraoperative periprosthetic humeral fractures in RTSA have an incidence of about 5% in this series of mainly uncemented press-fit stems. They generally heal without any further treatment and are not associated with stem loosening or compromise the clinical outcome after primary RTSA. Except slight restriction in the postoperative rehabilitation protocol, no further attention or action is needed.

Novel classification system for periprosthetic distal femoral fractures: a consideration for comminution.

PURPOSE: Comminution is an aspect of periprosthetic distal femoral fractures (PDFFs) that can influence postoperative outcomes and treatment selection, but is not included in current classification systems. We propose a new classification system for PDFFs based on comminution and cortical reads. This study aims to prove its reliability and efficacy to predict fracture severity and guide treatment. METHODS: A retrospective chart review of patients treated with single or dual locking plates for PDFFs was performed. Two fellowship-trained orthopedic joint reconstruction specialists used available imaging to classify each PDFF as either type 1 (minimal or no comminution allowing for reconstruction of medial and lateral cortices), type 2 (comminution reasonably allowing for reconstruction of either medial or lateral cortex), and type 3 (extensive comminution not allowing reasonable reconstruction of medial or lateral cortex). Each PDFF was then analyzed for radiographic outcomes including lateral distal femoral angle (LDFA) and the posterior distal femoral angle (PDFA). RESULTS: Interobserver reliability assessed by Cohen's Kappa statistic was 0.707, and average intraobserver reliability was 0.843, showing substantial reliability. Type 3 PDFFs had greater varus deformity than type 1 (p = 0.0457) or 2 (0.0198). CONCLUSION: The proposed classification system accounts for comminution, demonstrates strong interobserver and intraobserver reliability, and can be used to guide treatment in regard to single versus dual plating. LEVEL OF EVIDENCE: Retrospective comparative study, Level IV.

Atypical periprosthetic femoral fracture with stem breakage: a case report.

Although the American Society for Bone and Mineral Research definition of atypical femoral fracture excludes periprosthetic fractures, fractures around the prosthesis with clinical features of atypical femoral fractures have been reported in the literature. All fractures reported thus far have been distal to the prosthetic segment; however, we encountered a case of a stress fracture in the middle of the femoral component segment. An 86-year-old woman with a history of bisphosphonate osteoporosis treatment and revisional total hip arthroplasty visited our outpatient clinic complaining of pain in the left thigh and groin. We diagnosed an incomplete atypical femoral fracture around the hip prosthesis; medical treatment was implemented. Two months later, the patient visited the emergency department with a complete subtrochanteric fracture with stem breakage. Without revision of the broken stem, two plates were applied after reduction. In this case, we recognized the possibility of a stress fracture but overlooked the possibility of stem breakage in an atypical femoral fracture. Even if it is not evident on the radiograph before complete fracture, clinicians should be alert to the signs of stress fracture in the middle of the femoral component segment, as they may be clues to atypical periprosthetic femoral fracture with stem failure. Isolated medical treatment plans are not recommended for incomplete subtrochanteric atypical periprosthetic femoral fracture. Instead, concomitant prophylactic plate fixation is recommended.

Open reduction and locked compression plate fixation, with or without allograft strut, for periprosthetic fractures in patients who had a well-fixed femoral stem: a retrospective study with an average 2-year follow-up.

BACKGROUND: The use of cortical strut allograft has not been determined for Vancouver type B1 or C fracture. This study aimed to evaluate the short-term efficacy of locking compression plating with or without cortical strut allograft in managing these types of fractures. METHODS: We retrospectively assessed 32 patients (17 males, 15 females; 23-88 years, mean: 67.2 years) with Vancouver type B1 or C fractures. Seventeen patients (Group A; B1 fractures in 15 hips, C fractures in 2 hips) were treated with open reduction and internal fixation with locking compression plates (group A). The other 15 patients (Group B; B1 in 14 hips, C in 1 hip) were fixed by locking compression plating combined with cortical strut allografting (group B). The fracture healing rate, healing time, complications and function were compared between these two groups. RESULTS: The mean follow-up time was 32.4 months (12 to 66), and the overall fracture union rate of the 32 patients was 96.9%. Group B had a higher fracture union rate than Group A, but the difference was not statistically significant. Group A had one case of nonunion of type B1 fracture and one case of malunion; the mean time to fracture healing was 5.3 months (3 to 9). In group B, all patients reached bony union without malunion, with a mean time of fracture healing of 5.1 months (3 to 8). CONCLUSION: Treatment of Vancouver type B1 or C fractures by locking compression plating, with or without cortical strut allografting, resulted in similar union rates in these patients. This suggest that, the use of cortical strut allografting should be decided cautiously.

Periprosthetic humerus fractures after shoulder arthroplasty: an evaluation of available classification systems.

BACKGROUND: Periprosthetic proximal humerus fractures (PPHFs) are a detrimental complication of shoulder arthroplasty, yet their characterization and management have been poorly studied. We aimed to determine the intra- and interobserver reliability of 4 previously described PPHF classification systems to evaluate which classifications are the most consistent. METHODS: We retrospectively reviewed 32 patients (34 fractures) that were diagnosed with a PPHF between 1990 and 2017. Patient electronic medical records and research electronic data capture (REDCap) were used for data collection. Post-PPHF radiographs in multiple views for all 34 cases were organized into an encrypted, randomized Qualtrics survey. Four blinded fellowship-trained shoulder and elbow surgeons graded each fracture using previously reported classification systems by (1) Wright and Cofield (1995), (2) Campbell et al (1998), (3) Worland et al (1999), and (4) Groh et al (2008), along with selecting a preferred management strategy for each fracture. Grading was performed twice with at least 2 weeks between each randomized attempt. Intraobserver reliability was calculated as an unweighted Cohen kappa coefficient between attempt 1 and attempt 2 for each surgeon. Interobserver reliability and agreeability between surgeons' preferred management strategies were calculated for each classification system using Fleiss kappa coefficient. The kappa coefficients were interpreted using the Landis and Koch criteria. RESULTS: The average intraobserver kappa coefficient for each classification was as follows: Wright and Cofield = 0.703, Campbell = 0.527, Worland = 0.637, Groh = 0.699. The overall Fleiss kappa coefficient for interobserver reliability for each classification was as follows: Wright and Cofield = 0.583, Campbell = 0.488, Worland = 0.496, Groh = 0.483. Interobserver reliability was significantly greater with the Wright and Cofield classification. Using Landis and Koch criteria, all the classification systems assessed demonstrated only moderate interobserver agreement. Additionally, the mean interobserver agreeability kappa coefficient for preferred management strategy was 0.490, indicating only moderate interobserver agreement. CONCLUSION: There is only moderate interobserver reliability among the 4 PPHF classification systems and the preferred management strategy for the fractures assessed. Of the 4 PPHF classification systems, Wright and Cofield demonstrated the greatest mean intraobserver reliability and overall interobserver reliability. Our study highlights a need for the development of a PPHF classification system that can achieve high intra- and interobserver reliability and that can allow for a standardized treatment algorithm in the management of PPHFs.

Peri-implant atypical femoral fracture after nail or plate osteosynthesis.

BACKGROUND: A lack of scientific information regarding the risk factors and diagnosis of peri-implant atypical femoral fracture (PI-AFF) exists. We report a case series of developed PI-AFF with a nail or plate construct wherein prior femoral fractures were already healed after osteosynthesis. This study aimed to identify the cause and risk factors of PI-AFF and to devise a preventive method based on this. METHODS: We identified 11 PI-AFFs displaying features of AFFs. All patients were ambulant females (mean age, 74.9 years). The mean T-score of the femur measured by DEXA (Dual Energy X-ray Absorptiometry) scan was 3.5. Osteosynthesis was performed with a plate and an intramedullary nail in six and five patients, respectively. Possible risk factors were investigated, including the used implant, the medication of bisphosphonate, the characteristics of previous fracture (AFF or non-AFF), and the co-existence of AFF on the contralateral side. RESULTS: The PI-AFFs developed at an average of 6.6 years from the time of prior fracture. All fractures were located at the screw through the plate or nail. Regarding anatomic locations, seven and four fractures were at the subtrochanteric area and diaphysis, respectively. Diaphyseal PI-AFFs occurred in plating cases, all of which were associated with excessive femoral bowing. Subtrochanteric PI-AFFs included all five patients with nail fixation, which occurred near a proximal interlocking screw. Six of the 11 patients were on bisphosphonate treatment before or at the time of fracture. The duration of bisphosphonate treatment was 6 years on average. Concerning the previous femoral fractures, seven and four patients were AFF and non-AFF, respectively. Considering the pathology on the contralateral leg, eight had suffered diaphyseal AFF. Four patients were treated nonoperatively. Seven patients needed an operation; 6 of them healed after reconstruction nailing, and one needed hip arthroplasty because of the associated displaced femoral neck fracture. CONCLUSIONS: PI-AFFs may develop through the screw hole at the subtrochanteric or diaphyseal area due to femoral fragility and stress riser effect of the implant. An improved osteosynthesis strategy may be necessary to avoid PI-AFFs when fixing osteoporotic femoral fractures.

Vancouver B and C periprosthetic fractures around the cemented Exeter Stem: sex is associate with fracture pattern.

INTRODUCTION: The aim of this study was to identify factors associated with the level of periprosthetic fracture involving a cemented polished tapered stem: Vancouver B or Vancouver C. METHODS: A retrospective cohort study of 181 unilateral periprosthetic fractures involving Exeter stems was assessed by three observers (mean age 78.5, range 39-103; mean BMI 27.1, 17-39; 97 (54%) male). Patient demographics, deprivation scores, BMI and time since primary prosthesis were recorded. Femoral diameter, femoral cortical thickness, Dorr classification and distal cement mantle length were measured from calibrated radiographs. Interobserver reliability was calculated using intraclass correlation coefficients (ICCs). Univariate and multivariate analysis was performed to identify associations with Vancouver B or C fractures. RESULTS: 160/181 (88%) Vancouver B and 21/181 (12%) Vancouver C-level fractures occurred at a mean of 5.9 ± 5.4 years (0.2-26.5) following primary surgery. Radiographic measurements demonstrated excellent agreement (ICC > 0.8, p < 0.001). Mortality was significantly higher following Vancouver C compared to B fractures: 90 day 14/160 Vs 5/21 (p = 0.05); 1 year 29/160 Vs 8/21 (p = 0.03). Univariate analysis demonstrated that Vancouver C fractures were associated with female sex, bisphosphonate use, cortical bone thickness, and distal cement mantle length (p < 0.05). On multivariate analysis, only female sex was an independent predictor of Vancouver C-level fractures (R2 =0.354, p = 0.005). CONCLUSION: Most PFFs involving the Exeter stem design are Vancouver B-type fractures and appear to be independent of osteoporosis. In contrast, Vancouver C periprosthetic fractures display typical fragility fracture characteristics and are associated with female sex, thinner femoral cortices, longer distal cement mantles and high mortality.

Periprosthetic fragility fracture of the femur after primary cementless total hip arthroplasty.

OBJECTIVES: Periprosthetic bone fragility due to stress shielding (SS) can be a risk factor of periprosthetic fracture after cementless total hip arthroplasty (THA). We aimed to obtain epidemiological information on periprosthetic fragility fracture of the femur (PPFF) after THA. METHODS: We retrospectively reviewed the medical records of 1062 hips that had undergone cementless THA. We evaluated the epidemiological data as well as the features of PPFFs. RESULTS: Of the 1062 hips, 8 (0.8%) were diagnosed with PPFFs. The survival rates, with the occurrence of PPFF as the end point, were 99.2% and 97.6% at 10 and 16 years postoperatively, respectively. When patients were classified as having either mild or severe SS on radiographs 5 years postoperatively, there was no significant difference in the survival rate, with PPFF as the end point. CONCLUSIONS: In our cases, the incidence of PPFF after cementless THA was 0.8%.

Endosteal substitution with medial plate in the treatment of acute distal femur fracture (AO/OTA type A): surgical technique and case-series.

INTRODUCTION: Distal Femur fractures account for 4- 6% of all femur fractures and can be challenging to treat. The aims of this study are: (1) to describe a surgical technique using a medial distal femur endosteal plate to augment the stability of standard lateral plate fixation; (2) to report the results of a case-series of acute distal femur fractures (AO/OTA Type A/ Vancouver periprosthetic fractures Type C) treated using this technique. METHODS: This study describes the surgical steps for placement of a medial endosteal plate in combination with lateral locking plate in a cadaver model using fluoroscopy guidance. In addition, a retrospective database chart review for all patients with acute distal femur fractures treated with this technique over the last five years was performed. Exclusion criteria were involvement of type B and C distal femur intraarticular fractures, treatment with other endosteal substitutions (i.e., intramedullary nail fixation and fibula allograft), and treatment for non-union or pathological fractures. RESULTS: Twelve patients were identified with mean age of 75 years. All patients were female and all of them were allowed full weight bearing and full range of motion exercises immediately post-operatively. The complete follow up for one patient was not available; however, the mean fracture union was confirmed at 3.8 months in 10 of 12 patients. One patient had a failed construct at three months in the context of a periprosthetic fracture with a loose implant that was initially thought to be stable. One acute superficial surgical site infection was reported and healed uneventfully following debridement, primary closure, and antibiotic treatment. CONCLUSION: We believe that the placement of a medial endosteal plate can be a useful augment for standard lateral plate fixation in acute distal femur fractures, particularly in the context of severe comminution or poor bone quality. Uneventful healing was confirmed in 10 of 12 cases and no patients were restricted with regard to motion or weight bearing immediately post-operatively. Further studies with larger sample size would be required to fully assess this technique. LEVEL OF EVIDENCE: IV. Therapeutic Study (Surgical technique and Cases-series).

Peri-implant fractures of the upper and lower extremities: a case series of 61 fractures.

PURPOSE: To assess outcomes for patients who sustained peri-implant fractures (PIFs). METHODS: Medical records of patients who sustained a PIF were reviewed for demographic, injury, outcome, and radiographic data. PIFs were classified using a reproducible system and stratified into cohorts based on fracture location. Clinical outcomes were evaluated for each cohort. RESULTS: Fifty-six patients with 61 PIFs with at least 6 months of follow-up were included. The mean age of the cohort was 60.4 ± 19.5 years. Twenty-two (36.1%) PIFs occurred in males, while 39 (63.9%) occurred in females. Fifty-two (85.2%) PIFs were sustained from a low-energy injury mechanism. PIFs were most often treated with plate/screw constructs (50.8%). Complications included: 6 (9.8%) nonunions, 5 of which were successfully treated to healing, 5 (8.2%) fracture related infections (FRI), and 1 (1.6%) hardware failure. Sixty (98.4%) PIFs ultimately demonstrated radiographic healing. CONCLUSION: PIFs are usually treated surgically and have a relatively high incidence of complications, with nonunion in femoral PIFs being the greatest. Despite this, the rate of ultimate healing is quite high.

In Silico Evaluation of Treatment of Periprosthetic Fractures in Elderly Patients After Hip Arthroplasty.

The aim of this study was to investigate the soundness of in silico finite element model (FEM) in the assessment of strain in the femur and in the components fixing the periprosthetic fracture in elderly patients after hip arthroplasty. From a group of 55 patients, aged 27-95, treated due to fractures after hip replacement in 2012-2018, 18 patients were separated out, aged over 85, out of whom 7 had type C fractures, according to the Vancouver classification. These seven patients formed the study group. The fractures were stabilized with a locking compression plate system and wire loops or by replacement of the endoprosthesis stem. The FEM was performed by processing radiological images of the femur, considering the stabilization type and osteoporotic bone characteristics. Each patient's FEM was counter compared to virtual in silico control showing a non-osteoporotic bone structure. We found that the strain was distinctly greater at the bone-implant interface after surgical stabilization with a multi-hole plate and cerclage wire loops in osteoporotic periprosthetic fractures when compared to the virtual non-osteoporotic bone. We conclude that the in silico model enables the assessment of strain distribution at the bone-implant interface, which helps identify the biomechanical incongruity of traditional bone stabilization methods in patients with osteoporotic bones.