Osteosarcoma After Total Knee Arthroplasty: A Case Report.

CASE: A 79-year-old woman presented with a periprosthetic fracture 8 years after a total knee arthroplasty (TKA). Radiographs demonstrated tibial implant loosening with severe osteolysis. A high-grade osteosarcoma around the prosthesis was diagnosed, and a supracondylar femoral amputation was performed. After 2 years, no complications have occurred. CONCLUSIONS: A malignant tumor around a TKA is extremely rare. Surgeons should remain vigilant with patients who present with rapidly progressive or very aggressive implant loosening with osteolysis. Owing to its complexity and potentially devastating prognosis, treatment should be guided by a specialist multidisciplinary team. Complex limb salvage procedures or amputation is usually required.

Traumatic Floating Total Hip Arthroplasty: A Case Report.

CASE: A 58-year-old woman with medical history of a left total hip arthroplasty performed by the direct anterior (DA) approach 2 years prior presented with left hip pain. She was found to have sustained a transverse Vancouver C periprosthetic femur fracture and an unstable periprosthetic pelvic fracture. CONCLUSIONS: This patient's case represents a previously not reported injury about a total hip arthroplasty-with disruption distal to the femoral implant and proximal to the acetabular implant, with the implant-to-bone interface unaffected. This case may guide future treatment of similar injuries.

Robotic-assisted total knee arthroplasty results in decreased incidence of anterior femoral notching compared to posterior referenced instrumented total knee arthroplasty.

OBJECTIVE: Periprosthetic fracture (PPF) is an uncommon but devastating complication after total knee arthroplasty (TKA). Anterior femoral notching (AFN) is one of a perioperative risk factor for PPF. The main purpose of this study was to compare between the rates of anterior femoral notching (AFN) and supracondylar periprosthetic femoral fracture (sPPF) of manual TKA and robotic arm-assisted TKA (RATKA). Meanwhile, blood loss, transfusion rates, inflammatory responses, complications, early clinical and radiological outcomes were also assessed. METHODS: This retrospective study included 330 patients (133 RATKA and 197 manual TKA). Differences in risks of inflammatory, blood loss, complications (periprosthetic fracture and periprosthetic joint infection), pre-operative and post-operative distal lateral femoral angle (LDFA), distal femoral width (DFW), prosthesis-distal femoral width (PDFW) ratio, AFN, femoral component flexion angle (FCFA), peri-operative and post-operative functional outcomes between the RATKA and manual TKA groups were compared. RESULTS: The operation time and postoperative CRP level in the RATKA group was significantly longer and higher than that in the manual TKA group (p < .001). However, there was no significant difference in postoperative WBC level (p = .217), hemoglobin loss (p = .362), postoperative drainage (p = .836), and periprosthetic fracture (p = 1.000). There was no significant difference in LDFA (p > .05), DFW(p = .834), PDFW ratio (p = .089) and FCFA (p = .315) between the two groups, but the rate of AFN in the RATKA group was significantly lower than that in the manual TKA group (p < .05). There was no significant difference in ROM between the two groups on POD3, POD 90 and 1 year (p < .05), but the FJS-12 score in the RATKA group was higher than that in the manual TKA group on 1 year (p = .001). CONCLUSION: Robotic-assisted total knee arthroplasty can decrease the incidence of anterior femoral notching compared to posterior referenced instrumented total knee arthroplasty.

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.

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.

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.

A high risk of postoperative periprosthetic femoral fracture in Dorr type C femurs: a retrospective cohort study with 10-year follow-up data and a preliminary monochromatic image analysis.

BACKGROUND: The authors applied Anatomique Benoist Girard II (ABG II) stems for total hip arthroplasty in some Dorr type C femurs as early attempts. Here, the authors compared the long-term follow-up results between ABG II stems and the 'well-performing' Corail stems and their monochromatic images. METHODS: Among 3214 primary total hip arthroplasty records, 43 short ABG II stems and 67 standard-length Corail stems implanted in Dorr type C femurs were eligible and enrolled in this retrospective cohort study, with a mean follow-up of 10.3 years. Revision rates, Harris hip scores, and radiologic signs were compared. Spectral CT scans from a representative sample were obtained, and monochromatic images were reconstructed. A quantitative method was developed to measure the volume of the gap around stems. Patient-specific finite element analysis was conducted to investigate the strains. RESULTS: The revision rate of ABG II stems was significantly higher than that of Corail stems (21 vs. 3%, P <0.05). In the monochromatic images, fewer spot-weld signs (2.2 vs. 3.4, P <0.05) and wider gaps around stems (1.64 cm 3 vs. 0.13 cm 3 , P <0.05) were observed on average in the ABG II group. The mean maximum principal strains of the proximal femurs in the ABG II group were close to the yield strains and significantly larger than those in the Corail group (0.0052 vs. 0.0011, P <0.05). CONCLUSIONS: There was a high risk of postoperative periprosthetic femoral fracture for ABG II stems in Dorr type C femurs. Monochromatic images provided some insight into the failure mechanism. LEVEL OF EVIDENCE: III.

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.

Periprosthetic acetabular fractures as a complication of total hip arthroplasty.

Periprosthetic acetabular fractures are rare but potentially devastating complications of total hip arthroplasty. As the number of total hip arthroplasties performed annually increases, so has the incidence of periprosthetic fractures, with the topic being spotlighted more frequently in the orthopaedic community. There is a particular sparsity of literature regarding periprosthetic acetabular fractures, with periprosthetic femoral fractures after total hip arthroplasty being traditionally far more commonly reported. This article aims to provide an up-to-date review of the epidemiology, risk factors, diagnostic challenges, classifications, and management strategies for periprosthetic acetabular fractures after total hip arthroplasty.

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.

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.

A lower canal fill rate and unreestablished vertical femoral offset may increase the risk of the postoperative periprosthetic fractures after cementless bipolar hemiarthroplasty for femoral neck fractures in elderly patients.

BACKGROUND: Periprosthetic fractures (PPFs) is one of the major causes of failure of hip arthroplasty with cementless stem; however, studies on the incidence and risk factors of PPFs after cementless hemiarthroplasty for femoral neck fractures (FNFs) are lacking. METHODS: This retrospective study included patients who underwent cementless bipolar hemiarthroplasty for displaced intracapsular FNFs. The demographic data were reviewed, Dorr classification was used to describe morphology of the femur, radiological parameters were measured including stem-shaft angle, canal fill ratio (CFR), canal flare index (CFI), morphologic cortical index (MCI), canal calcar ratio (CCR), and vertical and horizontal femoral offset. RESULTS: The sample comprised 10 men and 46 women (affected hip: left, 38; right, 18). The mean patient age was 82.82±10.61 (range, 69-93) years, and the mean hemiarthroplasty to PPFs time was 26.28±14.04 (range, 6.54-47.77) months. Seven (12.28%) patients had PPFs. A significant relationship was found between the incidence of PPF and CFR (p = 0.012), patients had a significantly smaller femoral stem CFR (0.76%±0.11%) than controls (0.85%±0.09%). The PPFs group had a significant shorter and unreestablished vertical femoral offset (p = 0.048). CONCLUSIONS: A smaller femoral stem CFR associated with a potentially unacceptably high PPFs risk in uncemented hemiarthroplasty for displaced FNFs may result from mismatched prosthesis and bone dimensions in the elderly population, especially when accompanied by a poorly reestablished vertical femoral offset. With increasing evidence of the benefits of cemented fixation, a cemented stem for the treatment of displaced intracapsular FNFs is recommended for such a elderly frail population.

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.

CT required to perform robotic-assisted total hip arthroplasty can identify previously undiagnosed osteoporosis and guide femoral fixation strategy.

Osteoporosis can determine surgical strategy for total hip arthroplasty (THA), and perioperative fracture risk. The aims of this study were to use hip CT to measure femoral bone mineral density (BMD) using CT X-ray absorptiometry (CTXA), determine if systematic evaluation of preoperative femoral BMD with CTXA would improve identification of osteopenia and osteoporosis compared with available preoperative dual-energy X-ray absorptiometry (DXA) analysis, and determine if improved recognition of low BMD would affect the use of cemented stem fixation. Retrospective chart review of a single-surgeon database identified 78 patients with CTXA performed prior to robotic-assisted THA (raTHA) (Group 1). Group 1 was age- and sex-matched to 78 raTHAs that had a preoperative hip CT but did not have CTXA analysis (Group 2). Clinical demographics, femoral fixation method, CTXA, and DXA data were recorded. Demographic data were similar for both groups. Preoperative femoral BMD was available for 100% of Group 1 patients (CTXA) and 43.6% of Group 2 patients (DXA). CTXA analysis for all Group 1 patients preoperatively identified 13 osteopenic and eight osteoporotic patients for whom there were no available preoperative DXA data. Cemented stem fixation was used with higher frequency in Group 1 versus Group 2 (28.2% vs 14.3%, respectively; p = 0.030), and in all cases where osteoporosis was diagnosed, irrespective of technique (DXA or CTXA). Preoperative hip CT scans which are routinely obtained prior to raTHA can determine bone health, and thus guide femoral fixation strategy. Systematic preoperative evaluation with CTXA resulted in increased recognition of osteopenia and osteoporosis, and contributed to increased use of cemented femoral fixation compared with routine clinical care; in this small study, however, it did not impact short-term periprosthetic fracture risk.

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.

Patient and technical contributors to periprosthetic fracture around the CPT stem.

INTRODUCTION: The incidence of postoperative periprosthetic fracture has been reported to be higher in polished tapered femoral stems with the CPT stem possibly of greatest concern. We report on the patient and surgical factors in a consecutive cohort of 2892 CPT stems implanted as part of a total hip construct, either electively or for the treatment of a fractured neck of femur (NOF) over a 15-year period. METHODS: The Bluespier departmental database was used to identify any patients who been treated for a Vancouver B periprosthetic fracture around a CPT stem from 2008 to 2021. Patient demographics, mechanism of injury and fracture type were recorded. X-rays were reviewed to identify technical issues that may have contributed to the fracture. RESULTS: A total of 70 fractures were treated. For elective cases the fracture rate was 1.52% while for stems implanted for treatment of a neck of femur fracture (NOF) it was 2.86%. There was a male preponderance and almost all fractures were low energy. The majority (52.9%) were B1 fractures. Only 8 (11.4%) involved a truly loose construct (B2L). The presence of an undersized and varus stem increased the risk of fracture particularly in the NOF population. DISCUSSION: The results in this series are consistent with the registry data regarding the rate of failure of the CPT stem related to periprosthetic fracture. The patient population is typical of those who sustain a proximal femoral fracture in terms of age although we report a male preponderance. The importance of surgical technique in the placement of a correctly sized and aligned stem, particularly in those patients undergoing hip replacement for a neck of femur fracture is highlighted.

Incomplete Periprosthetic Atypical Femoral Fracture With Concomitant Hip and Knee Arthroplasties: A Case Report.

CASE: We present a case of an incomplete periprosthetic femoral fracture at the mid-distal third of the femoral stem after 11 months of bisphosphonate use. It is 1 of 4 cases of mid-distal periprosthetic atypical femoral fractures (PAFFs) found in our literature review. She was treated with protected weight-bearing, cessation of bisphosphonates, and teriparatide. Eighteen months after diagnosis, follow-up radiographs showed a bridging callus and reduction of a transverse fracture line. CONCLUSION: The incomplete PAFF was contributed by both decreased bone turnover from bisphosphonate use and increased mechanical stress at the lateral femoral cortex. Her previous left bipolar hemiarthroplasty and subsequent Total Knee Arthroplasty shifted the mechanical alignment medially, hence increasing tensile stress.

Periprosthetic distal femur fractures treated by retrograde intramedullary nails with a 10-degree distal bend achieve significantly better post-operative radiographic alignment when compared to conventional retrograde nails.

INTRODUCTION: Periprosthetic distal femur fractures (PPDFFs) are a common complication after total knee arthroplasty (TKA). In the setting of well-fixed TKA components, treatment options include retrograde intramedullary nailing (rIMN) or lateral locked plating. Treatment with rIMN has historically been associated with potential for extension deformity when using conventional nails. We hypothesized that the PPDFFs treated with an intramedullary nail with a specifically designed 10-degree distal bend for periprosthetic fractures would result in improved post-operative sagittal alignment compared to conventional intramedullary nails. MATERIALS AND METHODS: The study was conducted at a level-1 trauma center over a 12-year period (2010 - 2022). Patients over the age of 18 who sustained a PPDFF treated with rIMN were identified. The primary outcomes of the study were post-operative coronal and sagittal alignment determined by reviewing post-operative radiographs. RESULTS: A total of 50 patients were included. Twenty-three patients were treated with a rIMN with a 10° distal bend. Twenty-seven patients were treated with a rIMN with distal bend of 5° The mean aPDFA for the 10° distal bend group was 81.7° compared to 92.8° in the 5° distal bend group (p<0.001). There were 3/23 (13%) significant sagittal plane deformities the 10° distal bend group compared to 11/27 (41%) in the 5° distal bend group (p = 0.03). There was one patient with a post-operative extension deformity in the 10° distal bend group compared to 11 patients in the 5° distal bend group (p = 0.02). CONCLUSION: Retrograde intramedullary nailing of PPDFF with a 10° distal bend results in significantly better alignment in the sagittal plane when compared to a conventional 5° nail. The use of a 5° nail resulted in an extension deformity significantly more frequently. We therefore recommend the utilization of a rIMN with a 10° distal bend when treating PPDFFs. SUMMARY: Periprosthetic distal femur fractures are a common complication following total knee arthroplasty. While several studies report on the use of retrograde intramedullary nails in the treatment of periprosthetic distal femur fractures, there are limited reports of the use of a novel retrograde intramedullary nail with a 10° distal bend in the treatment of these injuries. Herein we present a radiographic study comparing coronal and sagittal postoperative alignment following treatment with retrograde intramedullary nails with a 10° distal bend versus conventional retrograde nails with a 5° distal bend.

Osteosynthesis versus revision arthroplasty in Vancouver B2 periprosthetic hip fractures: a systematic review and meta-analysis.

PURPOSE: Several studies comparing osteosynthesis and stem revision in Vancouver B2 (VB2) periprosthetic hip fractures (PPHF) have been published. This work aims to be the first systematic review and meta-analysis to include only studies involving statistical comparison between the two techniques. METHODS: MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were systematically searched from inception to October 2021 for studies involving a comparison between VB2 treated by osteosynthesis versus revision arthroplasty. The effect size (ES) was calculated using Cohen´s d index. RESULTS: From 17 published studies selected, a total of 856 patients were recruited (363 osteosynthesis / 493 revision arthroplasty). The pooled ES estimates for the Parker mobility score were 1.03 (95% CI, 0.22-1.84; I2 = 87.7%) for ORIF surgery, and 0.54 (95% CI, - 0.10-1.17; I2 = 83%) for revision surgery. The pooled ES estimates for the operative time, reintervention, complications, hospital stay and needing for blood transfusion were significant lower in ORIF than in revision surgery. There were no differences in first-year mortality between groups. There was a higher proportion of ASA > 3 patients in the ORIF group. CONCLUSION: Osteosynthesis versus revision arthroplasty has a shorter operative time, less need for blood transfusion, fewer complications and reoperation rate and shorter hospital stay. Nonetheless, similar results were found for functional tests and first-year mortality. These results support the use of osteosynthesis in selected patients (low functional demand, multiple comorbidities, and high anesthetic risk). LEVEL OF EVIDENCE: III.