Interprosthetic Femoral Fractures Research Articles

Incidences and Outcomes of Operatively Treated Interprosthetic Femoral Fractures Compared to Vancouver Type C and Rorabeck Type II Fractures

BackgroundThis case-control study evaluated the incidences and outcomes of interprosthetic femoral fracture (IPFF) (Group I) and performed comparisons with Vancouver type C (Group II) and Rorabeck type II (Group III) periprosthetic femoral fractures (PPFF) occurring at similar anatomic sites. MethodsA retrospective analysis was performed for all patients who had a previously implanted total hip arthroplasty (THA) and total knee arthroplasty (TKA), who lived in the hospital district and had undergone surgery due to PPFF. A total of 153 PPFFs [Group I (n = 31), Group II (n = 21), and Group III (n = 108)] were included. The annual incidences of PPFFs were summarized per 100,000 individuals. The risks of complications, reoperations, and mortalities were evaluated for all groups. ResultsThe mean population-based annual incidence was 0.9 per 100,000 person years for Group I, 0.7 per 100,000 person years for Group II, and 3.1 per 100,000 person years for Group III. A total of 25 of 153 (16%) major complications were found and 23 of 153 (13%) cases resulted in a revision surgery. The cumulative incidence of death in Group I was 50.4% at 10 years, in Group II it was 63.8% at 10 years, and in Group III it was 74.9% at 10 years. ConclusionThe annual incidence of the IPFF almost doubled while the incidence of Vancouver type C stayed stable and Rorabeck type II incidence increased 5-fold. Most of the major complications occurred in IPFF group, while Rorabeck type II patients had the worst survival.

Peri- and Interprosthetic Femoral Fractures-Current Concepts and New Developments for Internal Fixation.

Treatment of peri- and interprosthetic fractures represents a challenge in orthopedic trauma surgery. Multiple factors such as osteoporosis, polymedication and comorbidities impede therapy and the rehabilitation of this difficult fracture entity. This article summarizes current concepts and highlights new developments for the internal fixation of periprosthetic fractures. Since the elderly are unable to follow partial weight bearing, stable solutions are required. Therefore, a high primary stability is necessary. Numerous options, such as new angular stable plate systems with additional options for variable angle screw positioning, already exist and are in the process of being further improved. Lately, individually produced custom-made implants are offering interesting alternatives to treat periprosthetic fractures.

Periprosthetic femoral fracture type and location are influenced by the presence of an ipsilateral knee arthroplasty implant: A case-control study of 84 interprosthetic femoral fractures

BackgroundThis multicentre case-control study compares Vancouver Classification System (VCS) grade and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture type in interprosthetic femoral fractures (IPFFs) between primary total hip arthroplasty (THA) and ipsilateral total knee arthroplasty (TKA) to periprosthetic femoral fracture (PFF) without ipsilateral TKA. MethodsData were collected following institutional approval. Eighty-four IPFFs were assessed for VCS grade and AO/OTA type. Each IPFF case (84) was matched to five PFF controls (360) by age, gender and stem fixation philosophy (SMD<0.1). VCS grade and AO/OTA type were compared between the IPFF and PFF groups using weighted proportions and medians. ResultsMedian (IQR) age of IPFF patients was 81.75 (76.57–85.33) years and 61 (72.6%) were female. The commonest VCS grade was B1 (34, 40.5%). The commonest AO/OTA type was spiral (51.8% of VCS B fractures; 50.0% of VCS C fractures). A greater proportion of fractures occurred distal to the stem in IPFF patients versus PFF patients (33.3% versus 18.2%, p = 0.003). VCS grade was significantly different between groups (p = 0.015). For VCS C fractures, twice as many AO/OTA transverse and wedge fractures occurred in the IPFF group compared to the PFF group (25.0% versus 12.6% and 7.1% versus 3.3%, respectively) although the overall difference was not statistically significant (p = 0.407). ConclusionThe presence of an ipsilateral TKA affects the location of PFF with more fractures occurring distal to the stem. A greater proportion of bending type fractures occurred when an ipsilateral TKA was present. These unstable fractures often require more complex surgery.

Current methods and treatment options for interprosthetic femur fracture: an overview

As life expectation is prolonged and the elderly population increases, we are witnessing a growth in the number of prosthesis implanted; therefore, an increase in interprosthetic femoral fractures can be expected in the next future. For this reason, a proper and specific classification system needs to be.Nowadays, depending on the localization of the fracture, Vancouver or Rorabeck classifications are used, and some attempts have been made to create a new one or adjust and adapt the previously mentioned systems. However, there is no unique classification system that is accepted worldwide.The goal would be a classification that permits identifying the correct surgical treatment based on the type of interprosthetic femoral fracture. A pragmatic grading scale to provide a standardised approach, so that the best possible outcomes could be achieved. Despite minimal diffusion, in our opinion the Pires classification system should be universally accepted and used.

Outcomes of operatively treated interprosthetic femoral fractures.

The prevalence of ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) is rising in concert with life expectancy, putting more patients at risk for interprosthetic femur fractures (IPFFs). Our study aimed to assess treatment methodologies, implant survivorship, and IPFF clinical outcomes. A total of 76 patients treated for an IPFF from February 1985 to April 2018 were reviewed. Prior to fracture, at the hip/knee sites respectively, 46 femora had primary/primary, 21 had revision/primary, three had primary/revision, and six had revision/revision components. Mean age and BMI were 74 years (33 to 99) and 30 kg/m2 (21 to 46), respectively. Mean follow-up after fracture treatment was seven years (2 to 24). Overall, 59 fractures were classified as Vancouver C (Unified Classification System (UCS) D), 17 were Vancouver B (UCS B). In total, 57 patients (75%) were treated with open reduction and internal fixation (ORIF); three developed nonunion, three developed periprosthetic joint infection, and two developed aseptic loosening. In all, 18 patients (24%) underwent revision arthroplasty including 13 revision THAs, four distal femoral arthroplasties (DFAs), and one revision TKA: of these, one patient developed aseptic loosening and two developed nonunion. Survivorship free from any reoperation was 82% (95% confidence interval (CI) 66.9% to 90.6%) and 77% (95% CI 49.4% to 90.7%) in the ORIF and revision groups at two years, respectively. ORIF patients who went on to union tended to have stemmed knee components and greater mean interprosthetic distance (IPD = 189 mm (SD 73.6) vs 163 mm (SD 36.7); p = 0.546) than nonunited fractures. Patients who went on to nonunion in the revision arthroplasty group had higher medullary diameter: cortical width ratio (2.5 (SD 1.7) vs 1.3 (SD 0.3); p = 0.008) and lower IPD (36 mm (SD 30.6) vs 214 mm (SD 32.1); p < 0.001). At latest follow-up, 95% of patients (n = 72) were ambulatory. Interprosthetic femur fractures are technically and biologically challenging cases. Individualized approaches to internal fixation versus revision arthroplasty led to an 81% (95% CI 68.3% to 88.6%) survivorship free from reoperation at two years with 95% of patients ambulatory. Continued improvements in management are warranted. Cite this article: Bone Joint J2021;103-B(7 Supple B):122-128.

168 Interprosthetic Fractures of The Femur: A Literature Review

Abstract Increasing age expectations and number of joint replacement procedures have made interprosthetic femoral fractures (IFF) a progressively more common diagnosis and a challenge for surgeons. A gold standard and universally accepted classifications and guidelines do not exist yet. Customized structured electronic searches performed in PubMed database. Relevant key terms: IFF, classification interprosthetic fracture, peri-implant femoral fracture, biomechanics interprosthetic femur fracture, radiographic femur fracture, risk factor IFF. 42 articles finally included (up to 2019). High morbidity and mortality linked to IFF. Standardised classifications, management guidelines and surgical approaches are not available yet. Periprosthetic classification systems are still utilized even if not entirely appropriate. High rate of failure is related to thinner cortical bone, larger medullary canals and variable stresses depending on the distance among implants. High complication rates in all studies. Stress risers and implant stability based on fracture patterns and stress forces. Several surgical options with no uniformity. Less invasive surgical procedures are associated to reduction of metalwork failure rate, better preservation of vascularization and better functional-clinical outcomes. Lack of specific classification systems and management guidelines. Several surgical options are available with no uniformity of results. Attention to stress risers and preservation of bone stock and vascularization are key aspects for better results.

Direct medical costs of interprosthetic femoral fracture treatment: A cohort analysis

IntroductionPeriprosthetic femoral fractures (PPFs) represent a challenging clinical problem with a fast-rising incidence. Interprosthetic fractures (IPFs) represent one of its most difficult variants. There is a paucity of data regarding the financial burden of PPFs, and none for IPFs. This study aims to estimate the direct medical cost of the surgical treatment of IPFs in NHS, and analyse the factors influencing this when using different methods of surgical treatment. MethodsA cohort of patients with IPFs treated in a single academic unit over a period of 8-years with different surgical methods was studied. In-hospital details, as well as outpatient follow-up data, were gathered relevant to their clinical and radiological outcome until discharge. Local and national NHS data were acquired from the financial department, as well as industry-related resources. The economic analysis was structured as a cost identification analysis (CIA) of the overall cohort, but also as a comparative best-case scenario (uncomplicated course till discharge) comparison between the 3 main different management strategies (a) revision arthroplasty (RTHA), b) plate fixation (ORIF), c) combination of implants (COMBO). ResultsData from 28 patients (22 females) with IPFs were analysed with a median age of 78.4 years. The overall direct medical cost of treating this cohort of patients was £468,330, with a median of £15.625 (range £10,128 to 33,060). Comparing the three different surgical modalities, the median cost in groups a, b, and c was £20,793 (range £12,110 to £24,116), £12,979 (range £10,128 to £20,555), and £22,316 (range £10,938 to £23,081) respectively. In all groups, the 2/3 of the identified costs were relevant to the inpatient stay. Transfusions were the highest (3 units of cRBC on average) to the patients that received a revision THA vs the other two groups (p=0.022). There was statistically significant higher mean overall cost between the RTHA and the ORIF groups (£19,453 vs. £14,201, p=0.0242), but not when compared with the COMBO cases (£19,453 vs. £18,788, p=0.86). ConclusionThe first cost identification study and “best case scenario” comparative analysis for IPFs demonstrated a significant overall direct medical cost, when managing these complex fractures with variable contemporary techniques. Evidence based reimbursement strategies should be developed to allow the sustainability of the clinical service we offer in this challenging patient population.

Interprosthetic femoral fractures managed with modern distal femoral locking plates: 10 years’ experience at a UK major trauma centre

IntroductionInterprosthetic femoral fractures (IFF) are rare but increasing with an ageing population. Operative management is challenging and there is currently a paucity of outcome data in literature. The purpose of this study was to evaluate outcomes of IFFs managed with modern distal femoral locking plates, in a larger sample size than previously published. MethodThis retrospective study reviewed 49 closed IFFs in 48 patients at a major trauma center from 2009 to 2019 occurring between previous total hip arthroplasty (n=38), hemi hip arthroplasty (n=3), dynamic hip screw (n=6) or cephalomedullary nail (n=2) and total knee arthroplasty. They were managed with Minimally Invasive Plate Osteosynthesis (MIPO) employing modern biological fixation techniques and stabilised with VA-LCP Condylar (Synthes; n=28) or Peri-Loc (S&N; n=21) plate. Clinical and radiographic outcomes were measured. ResultsThe majority of fractures were in female patients (80%), who were elderly (average 83 years), and comorbid (55% ASA grade 3 or 4). Most fractures were Pires type IIA and OTA/AO type 33A. Average plate spanning femur was 16 holes, with average working length of 6 holes. 86% had unrestricted weight bearing immediately post operatively. 31 fractures reached radiological (n=25) or clinical (n=6) union. 13 patients died with 2 lost to follow up. There were 3 non-unions, with implant failure occurring before 4 months in all 3. We present a union rate of 91% (n=31/34). ConclusionIFFs are occurring with increasing frequency in a frail elderly population. In patients with IFFs, MIPO and biological fixation techniques using modern distal femoral locking plates can achieve high rate of union when combined with immediate unrestricted weight bearing postoperatively.

Presentation and Management of an Interprosthetic Femoral Fracture between a Total Hip Arthroplasty and Revised Total Knee Arthroplasty with Distal Femoral Replacement

An 83-year-old female sustained a right femoral interprosthetic fracture following a fall, She had a high BMI with a background history of ischaemic heart disease and type II diabetes. She was placed in a Thomas splint and underwent surgical fixation with a plate on the following trauma list.

Minimally invasive double-plating osteosynthesis of the distal femur.

Technical description of minimally invasive double-plating of the distal femur. Peri- and interprosthetic distal femur fractures with limited (periprosthetic) bone stock in geriatric patients. Re-operations (delayed and non-unions; infected non-unions) of the distal femur. Distal femoral fractures or femoral shaft fractures that do not qualify for femoral nailing and where the patient is unable to comply with weight-bearing restrictions. Peri- and interprosthetic femoral fractures with unstable knee prosthesis and local soft tissue infection. Peri- and interprosthetic fractures of the proximal femur. Supine position on a radiolucent table with both legs draped free. Support the knee to release traction on the distal fragment by the gastrocnemius muscle. Reduction and fixation of the fracture using a minimally invasive lateral approach. To reduce stress riser zones in interprosthetic fractures, the fixation device should overlap both the prosthesis by at least twice the diameter of the femoral diaphysis. Control plate position and reduction with special emphasis on length, rotation and longitudinal axes, using the healthy side as a reference. After sufficient reduction and fixation of the fracture, one proceeds to the medial plate fixation of the femur. Pre- or intraoperative contouring of a narrow large fragment locking compression plate into a helical shaped plate should be performed, using bending irons and a saw bone of a standard femur. The helical shaped plate is introduced submuscular and epiperiosteal in a minimally invasive fashion and fixed with bicortical locking screws. Unrestricted weight bearing with walker or crutches under supervision of physiotherapist. Between 2015 and December 2018, minimally invasive double-plate osteosynthesis using amedial helical shaped plate was performed in 11patients. In 6cases it was applied in patients (81years ± 7SD) with asupracondylar peri- or interprosthetic femoral fracture. No implant failure or loss of reduction was seen after postoperative unrestricted weight bearing. In the additional 5cases double-plating was used in salvage procedures ([infected] non-unions, hardware failure). One of these patients developed afracture-related infection for which all material was removed. The fracture healed after anew attempt of antegrade nailing combined with an additional locking plate. In the remaining patients complete bone healing without hardware failure was seen.

Internal fixation and revision arthroplasty for interprosthetic femoral fractures: a case series of fifty patients.

The aim of this study was to assess patients treated for interprosthetic femoral fractures (IFFs). Based on our database, we performed a retrospective single-center analysis of patients who underwent surgery for the treatment of IFFs. We evaluated patient demographics, fracture patterns, type of surgery, revision, and mortality for a minimum of one year after treatment. Outcomes were assessed via telephone using the Parker score. Fifty consecutive patients were enrolled. An analysis of fracture patterns revealed three different types: proximal (n = 19), intermediate (n = 13), and distal (n = 18). Treatment included internal fixation for stable components and revision arthroplasty for loose implants; and a lateral locking plate was the most commonly applied device. The mean follow-up time of the total sample was 5.7years after the operation. The total revision rate was 22%, and the highest revision rate was documented for revision arthroplasty. The oneyear mortality rate for the sample was 14%, and fracture patterns and treatment revealed no effects on mortality. Living patients (n = 23) were followed up for an average of 4.9years after treatment. Only six patients reported the best Parker score (mean, 5.0; range 0-9). IFFs can be divided into three groups irrespective of the type of stem or bone quality, but fixation (stable or loose) must also be considered to determine the treatment. Fracture patterns and treatment revealed no effects on mortality. There are many treatment options but no single solution for IFFs.

Lower reoperation rate with locking plates compared with conventional plates in Vancouver type C periprosthetic femoral fractures: A register study of 639 cases in Sweden

AimTo investigate demographics and outcomes of Vancouver type C periprosthetic femoral fractures (PPFF) treated with open reduction and internal fixation. MethodsPatient data were obtained from medical charts of cases reported to the Swedish Hip Arthroplasty Register and/or from the National Patient Register. Vancouver type C fractures undergoing surgery between 2001 and 2011, in patients who had received their primary THR between 1979 and 2011, were included. Any further reoperation performed between 2001 and 2013 and related to the PPFF constituted the primary outcome. ResultsA total of 632 patients with 639 Vancouver type C fractures were identified. The majority of the patients were women (84%) and they had a fracture distal to a cemented stem (95%). The mean age at the time of fracture was 72 years. Treatment was performed with a locking plate (363 cases), a conventional plate (184 cases), an intramedullary nail (62 cases), or with double plating (30 cases). The overall reoperation rate was 17%, and mortality within one year of the operation was 16%. Locking plates had a significantly lower reoperation rate than conventional plates (p<0.001) and intramedullary nailing (p = 0.005). Interprosthetic femoral fractures did not have a statistically different outcome compared with non-IPFFs. ConclusionsThe lowest reoperation rate was observed using locking plates in Vancouver type C fractures when compared with conventional plates or intramedullary nailing. The presence of an ipsilateral knee prosthesis did not influence the outcome of the surgical treatment.

Résultats du traitement chirurgical des fractures interprothétiques

IntroductionInterprosthetic fractures occur between a total knee replacement and a femoral stem of either a hemiarthroplasty or total hip replacement. The number of interprosthetic fractures will increase as the number of joint replacements rises. There is currently a paucity of literature looking at the outcomes of interprosthetic fractures. Therefore, we performed a retrospective study to: (1) Determine fracture union in patients following surgical treatment of a femoral interprosthetic fracture, (2) measure outcomes included mortality and complications. HypothesisFavouring bone fixation instead of prosthetic revision gives an acceptable rate of re-operation. Materials and MethodsA retrospective case note review of all interprosthetic femoral fractures admitted to a tertiary trauma centre over a 7-year period. There were 24 patients (4 males and 20 females) with a mean age of 82.3 (65–98). The initial operative procedure was a total hip replacement (THR) and a total knee replacement (TKR) in 19 patients, one THR and revision TKR, four hip hemiarthroplasty and TKR. There were 23-cemented femoral stems, and 1 uncemented femoral stem. The median time to surgery was 84hours. The median length of hospital stay was 16 days. Nineteen patients underwent open reduction internal fixation and 1 of these used a strut graft. Two patients underwent revision knee replacements and 3 underwent a revision hip replacement. All patients had at least 2 years clinical follow-up. ResultsOne patient died within 30 days of fracture, leaving 23 patients to assess bone union. Another patient died within 1 year of fracture. Three out of 24 patients (12.5%) suffered a complication that required further surgery. The fracture united in 19/23 (82.6%) of patients and the two-year mortality rate was 5/24 (20.8%). DiscussionInterprosthetic fractures are complex fractures occurring in elderly patients with multiple medical comorbidities. Whenever possible bone fixation instead of prosthetic revision give a low rate of complication and re-operation. The surgical treatments are complex, but with a well-performed surgical technique and an adequate rehabilitation program can result in satisfactory outcomes. Level of evidenceIV, Retrospective Case series.

Interprosthetic Femoral Sleeves in Revision Arthroplasty: A 20-Year Experience

BackgroundInterprosthetic femoral fractures in patients with ipsilateral stemmed total hip arthroplasty (THA) and total knee arthroplasty (TKA) can be technically demanding to treat surgically. Nonunion and implant failure are among the main complications following fixation of interprosthetic femoral (IF) fractures. Total femoral arthroplasty (TFA) is associated with a high incidence of infection and instability. IF sleeves have been designed to avoid the disadvantages of these techniques and to provide a stable construct. The aim of this study was to present the results with this device from a single center. MethodsWe reviewed 26 patients who underwent revision arthroplasty procedures, using custom-made cemented IF sleeves between 1997 and December 2017 in our institution. Two-part sleeves were used in 18 patients and one-part sleeves in 8 patients. The most common indication was an IF fracture (18 patients). Patients were monitored for postoperative complications, implant failure, and re-revision. The minimum follow-up of the survivors with nonrevised sleeves was 12 months. ResultsTwenty-three patients were included for the final analysis. The mean survivorship of the IF sleeve was 4.6 years at latest follow-up (mean 48.5 months; range 12 to 156). The overall rate of complications was 47.8%. The rate of mechanical failure was 21.7%. Late infections occurred in 3 patients (13%). At the latest follow-up, the mean Harris Hip Score was 69.9 points (range 39 to 94), and the mean functional Knee Society Score was 42.5 points (range 0 to 90), with average knee flexion of 95° (range 90° to 100°). ConclusionThe IF sleeve is a valid technique for the management of selected patients with IF fractures, particularly when a stable fracture fixation is not possible. Hip instability is not a concern, and functional improvement is achievable. Careful planning is required preoperatively to avoid mechanical failure.

Outcome of surgical treatment of inter prosthetic fractures: A case series

IntroductionInterprosthetic fractures occur between a total knee replacement and a femoral stem of either a hemiarthroplasty or total hip replacement. The number of interprosthetic fractures will increase as the number of joint replacements rises. There is currently a paucity of literature looking at the outcomes of interprosthetic fractures. Therefore, we performed a retrospective study to: (1) determine fracture union in patients following surgical treatment of a femoral interprosthetic fracture, (2) measure outcomes included mortality and complications. HypothesisFavoring bone fixation instead of prosthetic revision gives an acceptable rate of reoperation. Materials and methodsA retrospective case note review of all interprosthetic femoral fractures admitted to a tertiary trauma centre over a 7-year period. There were 24 patients (4 males and 20 females) with a mean age of 82.3 (65–98). The initial operative procedure was a total hip replacement (THR) and a total knee replacement (TKR) in 19 patients, one THR and revision TKR, four hip hemiarthroplasty and TKR. There were 23 cemented femoral stems, and 1 uncemented femoral stem. The median time to surgery was 84hours. The median length of hospital stay was 16 days. Nineteen patients underwent open reduction internal fixation and 1 of these used a strut graft. Two patients underwent revision knee replacements and 3 underwent a revision hip replacement. All patients had at least 2 years clinical follow-up. ResultsOne patient died within 30 days of fracture, leaving 23 patients to assess bone union. Another patient died within 1 year of fracture. Three out of 24 patients (12.5%) suffered a complication that required further surgery. The fracture united in 19/23 (82.6%) of patients and the 2-year mortality rate was 5/24 (20.8%). DiscussionInterprosthetic fractures are complex fractures occurring in elderly patients with multiple medical comorbidities. Whenever possible bone fixation instead of prostehtic revision give a low rate of complication and reoperation. The surgical treatments are complex, but with a well-performed surgical technique and an adequate rehabilitation program can result in satisfactory outcomes. Level of evidenceIV, retrospective case series.

The Baba classification focused on implant designs is useful in setting the therapeutic strategy for interprosthetic femoral fracture.

The purpose of this study was to investigate the clinical outcomes of femoral fracture with implants on the proximal and distal sides to verify whether actual fracture morphologies follow the fracture types of Baba classification focusing on implant designs useful for periprosthetic femoral fracture. Prosthesis was present in 85 with periprosthetic femoral fractures. Excluding 73 patients with fracture around the femoral stem or fracture of the TKA femoral component alone, 12 patients with 14 legs with both implants were investigated. All patients were radiographically assessed for implant stability according to the Baba classification. For clinical evaluation, intra- and postoperative complications, the operation time, and intra-operative blood loss were investigated. The Baba classification fracture type showed the implant as unstable and stable types in 3 and 11 legs, respectively. The consistency rate between the Baba classification-based judgment of plain radiograms acquired at the time of injury and actual surgical findings was 100%. As a result of treatment according to the Baba classification, bone union was achieved in all patients. There were no intra- or postoperative complications. Applying the Baba classification, implant stability could be sufficiently evaluated in not only periprosthetic femoral fractures following hip arthroplasty, but also interprosthetic femoral fractures, thereby verifying its usefulness in setting the treatment strategy.

Validation of a new classification system for interprosthetic femoral fractures

Interprosthetic femoral fracture (IFF) incidence is gradually increasing as the population is progressively ageing. However, treatment remains challenging due to several contributing factors, such as poor bone quality, patient comorbidities, small interprosthetic fragment, and prostheses instability. An effective and specific classification system is essential to optimize treatment management, therefore diminishing complication rates. This study aims to validate a previously described classification system for interprosthetic femoral fractures.

Interprosthetic femoral fractures: Treatment with a lateral angular-stable plate

ObjectiveTo study the causes and outcomes of patients with interprosthetic femoral fractures. Material and methodsA retrospective review conducted on 7 patients treated between 2010 and 2013. The knee arthroplasties had been implanted for at least 5 years, and those of the hip less than a year. They were bipolar cemented in 6 patients and totally non-cemented in one patient, all of them implanted due to a displaced femoral neck fracture. They were treated using osteosynthesis with angular stability plate covering the whole interprosthetic femoral segment. Except for one patient, all have been reviewed at least 12 months. ResultsThe patients included 6 women and one man, with a mean age of 84.7. The fracture, always by low energy, occurred between 2 and 8 months after that of the hip without the implants being mobilised. Four of them were located at diaphyseal level, and 3 at supracondylar level, and unrelated to the type of knee implant. There was consolidation in all patients at a mean of 4.5 months, without a re-operation in any of them, and with no mortality during the follow-up period. All patients walked independently at the time of the fracture, and all of them have managed to return to walking independently, having lost as average 20° of knee flexion in cases of supracondylar fracture. ConclusionsThe most important factors in our patients regarding the producing of the fracture have been the changes in the ability to walk after knee replacement and bone fragility. Angular stability plates give good results in the treatment of interprosthetic femoral fractures.

Fracturas interprotésicas femorales. Tratamiento con placa lateral de estabilidad angular

ObjectiveTo study the causes and outcomes of patients with interprosthetic femoral fractures. Material and methodsA retrospective review conducted on 7 patients treated between 2010 and 2013. The knee arthroplasties had been implanted for at least 5 years, and those of the hip less than a year. They were bipolar cemented in 6 patients and totally non-cemented in one patient, all of them implanted due to a displaced femoral neck fracture. They were treated using osteosynthesis with angular stability plate covering the whole interprosthetic femoral segment. Except for one patient, all have been reviewed at least 12 months. ResultsThe patients included 6 women and one man, with a mean age of 84.7. The fracture, always by low energy, occurred between 2 and 8 months after that of the hip without the implants being mobilized. Four of them were located at diaphyseal level, and 3 at supracondylar level, and unrelated to the type of knee implant. There was consolidation in all patients at a mean of 4.5 months, without a re-operation in any of them, and with no mortality during the follow-up period. All patients walked independently at the time of the fracture, and all of them have managed to return to walking independently, having lost as average 20° of knee flexion in cases of supracondylar fracture. ConclusionsThe most important factors in our patients regarding the producing of the fracture have been the changes in the ability to walk after knee replacement and bone fragility. Angular stability plates give good results in the treatment of interprosthetic femoral fractures.

Clinical outcome of interprosthetic femoral fractures treated with polyaxial locking plates

IntroductionTotal hip arthroplasty (THA) and total knee arthroplasty (TKA) are common procedures in the increasing older population. According to the AAOS, approximately 19,200 Americans are actually living with ipsilateral prosthetic hip and knee leading to 240 interprosthetic fractures annually. Few reviews and case reports give an idea of the obvious problem to achieve consolidation in interprosthetic fractures. Preconfigured plates have been shown to be superior compared with other treatments in patients with stable components. Utilization of internal fixators for interprosthetic fractures might be advantageous.The purpose of this study was to evaluate interprosthetic femoral fractures with polyaxial locking plate treatment in regard to surgical procedure, complications, and clinical outcome. MethodsBetween 2005 and 2012, 143 patients underwent surgical treatment for periprosthetic femur fractures. Thirty-two fractures were identified as interprosthetic fractures. Five patients were excluded. Fractures were classified according to OTA/AO system, Vancouver, Rorabeck, Soenen and Pires. Trauma fellowship trained orthopaedic surgeons performed the surgeries using a NCB-construct (Zimmer Inc., Warshaw, IN). Plate choice was determined according to radiographic classification. Submuscular plate insertion was performed if possible. Complications were recorded concerning infection, union, fixation failure, and revision surgery. ResultsTwenty-seven patients were identified. There were 92.6% females. Follow-up by regular outpatient clinic visits was 24 months. Surface replacements were found in 18 TKA. Nine patients had a stemmed femur component of their TKA. 89% healed after the index procedure. Three patients developed a nonunion with 1 construct leading to hardware failure. Previous revision THA or Pires/modified Vancouver classification did not influence nonunion formation, but all patients with nonunion formation were classified as AO/OTA type B (p=0.001). These fractures were treated with longer plates (p=0.015), but with similar working length (p=0.400). Plate design, additional cerclages, or submuscular insertion did not influence nonunion formation. ConclusionInterprosthetic fracture treatment remains challenging. NCB-locked plating can achieve satisfactory results. Additional soft tissue damage can be prevented by submuscular plate insertion. Treatment of type B fractures resulted in significantly greater nonunion rate. Therefore, consideration of the individual fracture type is essential to determine plate length, plate type, and additional bone grafting or BMP supplementation.