Aims

Periprosthetic hip fractures (PPFs) after total hip arthroplasty are difficult to treat. Therefore, it is important to identify modifiable risk factors such as stem selection to reduce the occurrence of PPFs. This study aimed to clarify differences in fracture torque, surface strain, and fracture type analysis between three different types of cemented stems.

Aims. The aim of this study was to describe services available to patients with periprosthetic femoral fracture (PPFF) in England and Wales, with focus on variation between centres and areas for care improvement. Methods. This work used data freely available from the National Hip Fracture Database (NHFD) facilities survey in 2021, which asked 21 questions about the care of patients with PPFFs, and nine relating to clinical decision-making around a hypothetical case. Results. Of 174 centres contributing data to the NHFD, 161 provided full responses and 139 submitted data on PPFF. Lack of resources was cited as the main reason for not submitting data. Surgeon (44.6%) and theatre (29.7%) availability were reported as the primary reasons for surgical delay beyond 36 hours. Less than half had a formal process for a specialist surgeon to operate on PPFF at least every other day. The median number of specialist surgeons at each centre was four (interquartile range (IQR) 3 to 6) for PPFF around both hips and knees. Around one-third of centres reported having one dedicated theatre list per week. The routine discussion of patients with PPFF at local and regional multidisciplinary team meetings was lower than that for all-cause revision arthroplasties. Six centres reported transferring all patients with PPFF around a hip joint to another centre for surgery, and this was an occasional practice for a further 34. The management of the hypothetical clinical scenario was varied, with 75 centres proposing ORIF, 35 suggested revision surgery and 48 proposed a combination of both revision and fixation. Conclusion. There is considerable variation in both the organization of PPFF services England and Wales, and in the approach taken to an individual case. The rising incidence of PPFF and complexity of these patients highlight the need for pathway development. The adoption of networks may reduce variability and improve outcomes for patients with PPFF. Cite this article: Bone Jt Open 2023;4(5):378–384

Aims. The objectives of this study were to investigate the patient characteristics and mortality of Vancouver type B periprosthetic femoral fractures (PFF) subgroups divided into two groups according to femoral component stability and to compare postoperative clinical outcomes according to treatment in Vancouver type B2 and B3 fractures. Methods. A total of 126 Vancouver type B fractures were analyzed from 2010 to 2019 in 11 associated centres' database (named TRON). We divided the patients into two Vancouver type B subtypes according to implant stability. Patient demographics and functional scores were assessed in the Vancouver type B subtypes. We estimated the mortality according to various patient characteristics and clinical outcomes between the open reduction internal fixation (ORIF) and revision arthroplasty (revision) groups in patients with unstable subtype. Results. The one-year mortality rate of the stable and unstable subtype of Vancouver type B was 9.4% and 16.4%. Patient demographic factors, including residential status and pre-injury mobility were associated with mortality. There was no significant difference in mortality between patients treated with ORIF and Revision in either Vancouver B subtype. Patients treated with revision had significantly higher Parker Mobility Score (PMS) values (5.48 vs 3.43; p = 0.00461) and a significantly lower visual analogue scale (VAS) values (1.06 vs 1.94; p = 0.0399) for pain than ORIF in the unstable subtype. Conclusion. Among patients with Vancouver type B fractures, frail patients, such as those with worse scores for residential status and pre-injury mobility, had a high mortality rate. There was no significant difference in mortality between patients treated with ORIF and those treated with revision. However, in the unstable subtype, the PMS and VAS values at the final follow-up examination were significantly better in patients who received revision. Based on postoperative activities of daily life, we therefore recommend evision in instances when either treatment option is feasible. Cite this article: Bone Jt Open 2023;4(1):38–46

Aims. The aims of this study were to evaluate the incidence of reoperation (all cause and specifically for periprosthetic femoral fracture (PFF)) and mortality, and associated risk factors, following a hemiarthroplasty incorporating a cemented collarless polished taper slip stem (PTS) for management of an intracapsular hip fracture. Methods. This retrospective study included hip fracture patients aged 50 years and older treated with Exeter (PTS) bipolar hemiarthroplasty between 2019 and 2022. Patient demographics, place of domicile, fracture type, delirium status, American Society of Anesthesiologists (ASA) grade, length of stay, and mortality were collected. Reoperation and mortality were recorded up to a median follow-up of 29.5 months (interquartile range 12 to 51.4). Cox regression was performed to evaluate independent risk factors associated with reoperation and mortality. Results. The cohort consisted of 1,619 patients with a mean age of 82.2 years (50 to 104), of whom 1,100 (67.9%) were female. In total, 29 patients (1.8%) underwent a reoperation; 12 patients (0.7%) sustained a PFF during the observation period (United Classification System (UCS)-A n = 2; UCS-B n = 5; UCS-C n = 5), of whom ten underwent surgical management. Perioperative delirium was independently associated with the occurrence of PFF (hazard ratio (HR) 5.92; p = 0.013) and surgery for UCS-B PFF (HR 21.7; p = 0.022). Neither all-cause reoperation nor PFF-related surgery was independently associated with mortality (HR 0.66; p = 0.217 and HR 0.38; p = 0.170, respectively). Perioperative delirium, male sex, older age, higher ASA grade, and pre-fracture residential status were independently associated with increased mortality risk following hemiarthroplasty (p < 0.001). Conclusion. The cumulative incidence of PFF at four years was 1.1% in elderly patients following cemented PTS hemiarthroplasty for a hip fracture. Perioperative delirium was independently associated with a PFF. However, reoperation for PPF was not independently associated with patient mortality after adjusting for patient-specific factors. Cite this article: Bone Jt Open 2024;5(4):269–276

Aims. This study aimed to investigate the optimal sagittal positioning of the uncemented femoral component in total knee arthroplasty to minimize the risk of aseptic loosening and periprosthetic fracture. Methods. Ten different sagittal placements of the femoral component, ranging from -5 mm (causing anterior notch) to +4 mm (causing anterior gap), were analyzed using finite element analysis. Both gait and squat loading conditions were simulated, and Von Mises stress and interface micromotion were evaluated to assess fracture and loosening risk. Results. During gait, varied sagittal positioning did not lead to excessive Von Mises stress or micromotion. However, under squat conditions, posterior positioning (-4 and -5 mm) resulted in stress exceeding 150 MPa at the femoral notch, indicating potential fracture risk. Conversely, +1 mm and 0 mm sagittal positions demonstrated minimal interface micromotion. Conclusion. Slightly anterior sagittal positioning (+1 mm) or neutral positioning (0 mm) effectively reduced stress concentration at the femoral notch and minimized interface micromotion. Thus, these positions are deemed suitable to decrease the risk of aseptic loosening and periprosthetic femoral fracture

Periprosthetic femoral fracture (PFF) following primary total hip arthroplasty (THA) is of raising concern with the aging of the population. The aim of this retrospective study was to assess the incidence of early PFF associated with Charnley- Kerboull (CK) stems cemented line-to-line according to the “French paradox” principles through the anterior approach (AA) in patients older than 70 years old. This monocentric study involved 25 surgeons with various level of experience. From a prospectively collected database, all CK stems (AmisK®, Medacta, Castel San Pietro, Switzerland) done consecutively from January 2018 to May 2022 through the AA in patients older than 70 years were included. The measured parameters included canal flare index (CFI), morphological cortical index (MCI), canal-calcar ratio (CCR), ilium-ischial ratio (IIR), ilium overhang, and anterior superior iliac spine (ASIS) to greater trochanter distance. Dorr classification was also recorded. A total of 416 CK stems performed by 25 surgeons were included. All patients had a minimal 3-month follow-up. The mean age was 77.4 years, and the mean BMI was 25.3 kg/m. 2. According to the Dorr classification 240 hips were of Dorr type A, 144 Dorr type B, and 2 Dorr type C. Mean CFI, MCI, CCR, IIR and ASIS-GT were 3.8, 0.5, 2.8, 2.5, and 101mm, respectively. Amongst the 416 THAs, one (0.24%; 95% CI 0.20 – 0.28%) early PFF Vancouver type B2 fracture that occurred 24 days postoperatively was observed. This study demonstrated that CK stems cemented according to the “French Paradox” were associated with an extremely low rate of early PFF in patients over 70 years. The observed results are better than those reported with uncemented or taper slip cemented stems. Longer follow-up is warranted to evaluate further rate of fracture that may occur during the bone remodeling process around the femoral component

Aims. This study evaluates risk factors influencing fracture characteristics for postoperative periprosthetic femoral fractures (PFFs) around cemented stems in total hip arthroplasty. Methods. Data were collected for PFF patients admitted to eight UK centres between 25 May 2006 and 1 March 2020. Radiographs were assessed for Unified Classification System (UCS) grade and AO/OTA type. Statistical comparisons investigated relationships by age, gender, and stem fixation philosophy (polished taper-slip (PTS) vs composite beam (CB)). The effect of multiple variables was estimated using multinomial logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs). Surgical treatment (revision vs fixation) was compared by UCS grade and AO/OTA type. Results. A total of 584 cases were included. Median age was 79.1 years (interquartile range 72.0 to 86.0), 312 (53.6%) patients were female, and 495 (85.1%) stems were PTS. The commonest UCS grade was type B1 (278, 47.6%). The most common AO/OTA type was spiral (352, 60.3%). Metaphyseal split fractures occurred only with PTS stems with an incidence of 10.1%. Male sex was associated with a five-fold reduction in odds of a type C fracture (OR 0.22 (95% CI 0.12 to 0.41); p < 0.001) compared to a type B fracture. CB stems were associated with significantly increased odds of transverse fracture (OR 9.51 (95% CI 3.72 to 24.34); p < 0.001) and wedge fracture (OR 3.72 (95% CI 1.16 to 11.95); p = 0.027) compared to PTS stems. Both UCS grade and AO/OTA type differed significantly (p < 0.001 and p = 0.001, respectively) between the revision and fixation groups but a similar proportion of B1 fractures underwent revision compared to fixation (45.3% vs 50.6%). Conclusion. The commonest fracture types are B1 and spiral fractures. PTS stems are exclusively associated with metaphyseal split fractures, but their incidence is low. Males have lower odds of UCS grade C fractures compared to females. CB stems have higher odds of bending type fractures (transverse and wedge) compared to PTS stems. There is considerable variation in practice when treating B1 fractures around cemented stems. Cite this article: Bone Jt Open 2021;2(7):466–475

Known risk factors for early periprosthetic femur fracture (PFF) following total hip arthroplasty (THA) include poor bone quality, surgical approach and cementless implants. The association between femoral component size and alignment and the risk of early PFF is not well described. We evaluated radiographic parameters of femoral component sizing and alignment as risk factors for early PFF. From 16,065 primary cementless THA, we identified 66 cases (0.41%) of early PFF (<90 days from index THA) at a single institution between 2016–2020. The stem was unstable and revised in all cases. We matched 60 cases of early PFFs (2:1) to 120 controls based on femoral component model, offset, surgical approach, age, BMI, and sex. Mean age was 67 years; 60% were female. Radiographic assessment of preoperative bone morphology and postoperative femoral component parameters including stem alignment, metaphyseal fill, and medial congruence with the calcar. A multivariable logistic regression was built to identify radiographic risk factors associated with early PPF. Markers of poor preoperative bone quality including canal calcar ratio (p=0.003), canal flare index (p<0.001), anteroposterior canal bone ratio (CBR) (p<0.001) and lateral CBR (p<0.001) were statistically associated with PFF. Valgus alignment (23% versus 12%) (p<0.001) was more prevalent in the PFF group compared to controls, as well as varus alignment of the implant (57% versus 43%). Distance between the medial aspect of the implant and the calcar was greater in cases of PFF (2.5 mm versus 1.4 mm) (p<0.001). Multivariate analysis demonstrated that valgus implant alignment (Odds Ratio (OR) 5) and medial implant-calcar incongruity (OR 2) increased the risk of early PFF. Medial implant-calcar incongruity and valgus alignment of the femoral component were risk factors for early PFF following cementless THA after controlling for age, sex, BMI, approach, proximal femoral morphology, and implant design

The recruitment drive, investment and collaboration within Betsi Cadwaladr University Health Board (BCUHB) sites providing specialist lower limb arthroplasty and trauma service has evolved over last few years with aims to improve patient care and reduce reliance on tertiary referral centres. Through our service-evaluation project, we reviewed the results of treatment provided for periprosthetic femur fractures (PPFFs) presenting to BCUHB sites over last 4 years. We retrospectively reviewed consecutive PPFFs admitted at three BCUHB sites from January’20 to June’23 with mean follow-up of 20.8 ± 13.2 (8–49) months [n=161; Mean age: 82.2 ± 8.5 (59–101) years, Females:107]. Over the review period we noted a 23% increase in service demand for care of PPFFs. Majority were managed surgically [132/161] [38 revision arthroplasties; 94 ORIFs] at BCUHB sites and two patients were referred to tertiary centre. Average time to surgery was 3.5 days. 90% of the PPFFs were managed successfully with 10% (16/159) having orthopaedic complications needing further intervention. 6.3 (10/159) had medical complications and did not need orthopaedic re-intervention. In our series, 12-month re-operation rate was 6.1% (8/132) and 1-month, 3-month and 1-year mortality rate was 6.3%, 11.3% and 21.4% respectively. These results are comparable to the published results of PPFF management at tertiary centres. Potential cost savings compared to transfer to tertiary centre for PPFF management was £2.31 million. Thus, it is possible to successfully provide adequate care for PPFFs at DGHs and efforts should be made to appropriately equip and adequately staff DGHs, to provide service for local PPFF care

Objective: The number of hip prostheses replacement surgeries particularly in elder people with osteoporosis, has been increasing every year; given this scenario, treatment of postoperative periprosthetic femoral fracture has become a critical problem. Osteosynthesis is generally selected as the procedure of choice for the surgical treatment of fractures, provided the stem prostheses do not show loosening. Stable fixation of periprosthetic femoral fracture is difficult in the elderly because they have osteoporotic bone and most of the intramedullary space is occupied by the metal stem implanted in the proximal femoral shaft. With a view to solving this problem, we developed a new surgical treatment for postoperative periprosthetic femoral fracture; this procedure use a trimming intramedullary nail, which we have termed “docking nail.” [Materials] The subjects were 3 patients (81, 75 and 76 years old) who had suffered a femoral shaft fracture around the femoral prosthesis after total hip replacement; in all 3 patients, there was no apparent sign of loosening of the stem prosthesis. The implanted stem was cemented in one patient and uncemented in the other two. Method: Using information on the size and shape of the stem prosthesis as well as information from the pre-operative radiographs, we cut the docking nail till the proper length was achieved and trimmed it to suit the cutting site in order to ensure that it was compatible with tip of the stem. We then performed osteosynthesis using instruments of an ordinary supracondylar type intramedullary nail. In cases where it was difficult to reposition or where it was necessary to remove excessive cement and bone from around the tip of stem and graft a free bone in the bony defect, we exposed the fracture site as minimally as possible. The major difference between our procedure and the conventional procedure is that in our procedure, the docking nail is connected to the tip of the implanted stem to ensure proper alignment. Postoperative immobilization was not used in any of the patients except for the 81-year-old patient, for whom partial weight-bearing was allowed at 4 weeks, and full weight bearing at 12 weeks. The mean follow up period was 22 months (range, 6–48 months). Result: Within 3 months, bony union with good alignment was achieved in all 3 patients without malunion or infection. The clinical and radiographic examinations conducted during the follow-up period showed good results. Conclusion: The advantages of this method are that it is less invasive and simple compared to the conventional methods. Its only disadvantage is that it requires considerable, preoperative planning and minor trimming of the nail. Although this series is small, we think that this new treatment can be recommended and will be beneficial for treating periprosthetic femoral fractures without a loose stem. However, these preliminary findings need to be confirmed by further investigations

Non-cemented tapered wedge femoral stems have gained popularity given their excellent long-term clinical success rates. However, there is sparse literature reporting the incidence of early postoperative periprosthetic femur fractures in patients with this stem design. The aim of this study is to report this incidence and to identify factors which may increase the risk of such fractures. The charts of all patients who were implanted with a single design of a tapered wedge femoral stem at a single institution were retrospectively reviewed to identify any early periprosthetic femur fractures, defined as occurring within the first year of surgery. Demographic, operative, and radiographic details were analyzed for potential risk factors that may predispose to periprosthetic fractures, and compared to a cohort of patients with the same implant that was matched for age, sex, and pre-operative diagnosis and did not have a periprosthetic fracture. Six fractures were identified in 2220 stems implanted over a five year period, for an incidence of 0.3%. The average time to fracture was nine weeks post-operatively. Five fractures were Vancouver Type B2, and the other was Vancouver Type A. Three stems were radiographically undersized, and two failed to achieve a proximal wedge fit because of distal fixation. When compared to the matched cohort, there was no statistical significance with regard to body-mass index, morphological cortical index, or canal-bone ratio. However the fracture cohort did have a statistically lower canal-calcar ratio (p < 0.05) and statistically higher canal-flare index (p < 0.05). Early postoperative periprosthetic femur fracture around a tapered wedge stem is a rare but potentially devastating complication. Risk factors which may predispose to fracture are a proximal-distal mismatch in femoral geometry and an undersized implant

To investigate predictors of periprosthetic fracture level (around stem (Vancouver B) or distal to stem (Vancouver C/D) in cemented polished tapered femoral stems. Retrospective cohort study of 188 patients (mean age 79 (range 30–91); 99 (53%) male) with unilateral periprosthetic femoral fractures associated with CPT stems. Medical notes were reviewed and the following recorded: patient demographics, past medical history, drug history, date of prosthesis insertion, and date of injury. Radiographs analysis included Vancouver classification, cement restrictor type, cement mantle to implant tip distance, cortical thickness, femoral diameter and DORR classification. Univariate, multivariate and ROC curve analysis was performed. Fractures occurred at mean 7.5 years following primary procedure: 152 (83%) were B fractures; and 36 (19%) C/D. On univariate analysis female gender, lower BMI, osteoporosis, NSAID use, Bisphosphonate therapy, cortical thickness, distal cement mantle length and distal cement mantle length:femoral diameter ratio were significantly associated with C level fractures (p<0.05). Distal cement mantle lengths of >19.6mm (AUC 0.688, p<0.001) were associate with C level fractures. Multivariate analysis demonstrated female gender and distal cement mantle length:femoral diameter ratio to be independent predictors of C level periprosthetic fractures. Though female sex is the largest independent predictor of periprosthetic fractures distal to a CPT femoral stem, the relationship between cortical thickness and distal cement mantle length appears significant. As fractures distal to the stem are invariably managed by ORIF, whereas fractures around the stem frequently require revision arthroplasty, this has relevance at primary surgery in osteoporotic females to reduce the need for complex revisions

Periprosthetic femoral shaft fractures are a significant complication of total hip arthroplasty. Plate osteosynthesis with or without onlay strut allograft has been the mainstay of treatment around well-fixed stems. Nonunions are a rare, challenging complication of this fixation method. The number of published treatment strategies for periprosthetic femoral nonunions are limited. In this series, we report the outcomes of a novel orthogonal plating surgical technique for addressing nonunions in the setting of Vancouver B1 and C-type periprosthetic fractures that previously failed open reduction internal fixation (ORIF). A retrospective chart review of all patients from 2010 to 2014 with Vancouver B1/C total hip arthroplasty periprosthetic femoral nonunions was performed. All patients were treated primarily with ORIF. Nonunion was defined as no radiographic signs of fracture healing nine months post-operatively, with or without hardware failure. Exclusion criteria included open fractures and periprosthetic infections. The technique utilised a mechanobiologic strategy of atraumatic exposure, resection of necrotic tissue, bone grafting with adjuvant recombinant growth factor and revision open reduction internal fixation. Initially, compression was achieved using an articulated tensioning device and application of an anterior plate. This was followed by locked lateral plating. Patients remained non-weight bearing for eight weeks. Six Vancouver B1/C periprosthetic femoral nonunions were treated. Five patients were female with an average age of 80.3 years (range 72–91). The fractures occurred at a mean of 5.8 years (range 1–10) from their initial arthroplasty procedure. No patients underwent further revision surgery; there were no wound dehiscence, hardware failures, infections, or surgical complications. All patients had a minimum of nine months follow up (mean 16.6, range 9–36). All fractures achieved osseous union, defined as solid bridging callus over at least two cortices and pain free, independent ambulation, at an average of 24.4 weeks (range 6.1–39.7 weeks). To our knowledge, this is the first case series describing 90–90 locked compression plating using modern implants for periprosthetic femoral nonunions. This is a rare but challenging complication of total hip arthroplasty and we present a novel solution with satisfactory preliminary outcomes. Orthogonal locked compression plating utilising an articulated tensioning device and autograft with adjuvant osteoinductive allograft should be considered in periprosthetic femur fractures around a well-fixed stem. Further biomechanical and clinical research is needed to improve our treatment strategies in this population

The increased torque required to dislocate dual mobility (DM) components may increase peri-prosthetic femoral fracture (PPF) risk. Current literature often relies on revision as an endpoint and may underestimate PPF. This study aims to review PPF rate, risks and treatment following primary DM implantation.

Prospective cohort study of 549 patients following primary DM total hip arthroplasty (THA) between 2013 and 2021. Collected data included demographics, indication for surgery, cortical index and PPF.

549 patients were identified with primary DM THA. Mean age was 73 years (26–96). 446 (81.2%) patients had their index surgery following hip fracture. 18 patients (3.27%) sustained a PPF. Cumulative PPF rate was 1.5% at 1-year, 2.2% at 5-years and 3.27% overall. PPF was higher in patients undergoing surgery following hip fracture (4%) vs. other indications (1%). OR 4.04 (95% CI:0.53, 30.72), p=0.219. Mean cortical index was lower in patients with PPF 0.4 (95% CI:0.36, 0.45) compared to those without 0.46 (95% CI:0.45, 0.46) p=0.029. Treatment for PPF included 10 (55.6%) open reduction internal fixation (ORIF), 7 (38.9%) revision THA and 1 conservatively managed.

PPF rate following DM use is higher in our cohort than published rates. Our rates are comparable to some papers when subgroup analysis of older patients and cemented taper slip stems are considered. PPF risk with DM may be increased in patients undergoing surgery after hip fracture or with a lower cortical index preoperatively. Over half of PPF were managed with ORIF and may mask PPF risk studies that report using revision as an endpoint.

There are a number of periprosthetic femoral fracture (PFF) fixation failures. In several cases the effect of fracture configuration on the performance of the chosen fixation method has been underestimated. As a result, fracture movement within the window that seems to promote callus formation has not been achieved and fixations ultimately failed. This study tested the hypothesis that: PFF configuration and the choice of plate fixation method can be detrimental to healing. A series of computational models were developed, corroborated against measurements from a series of instrumented laboratory models and in vivo case studies. The models were used to investigate the fixation of different fracture configurations and plate fixation parameters. Surface strain and fracture movement were compared between the constructs. A strong correlation between the computational and experimental models was found. Computational models showed that unstable fracture configurations increase the stress on the plate fixation. It was found that bridging length plays a pivotal role in the fracture movement. Rigid fixations, where there is clinical evidence of failure, showed low fracture movement in the models (<0.05mm); this could be increased with different screw and plate configurations to promote healing. In summary our results highlighted the role of fracture configuration in PFF fixations and showed that rigid fixations that suppress fracture movement could be detrimental to healing

It is unknown whether the risk of periprosthetic femoral fracture is the same in patients with two different bearing surfaces, ceramic on ceramic (CoC) and ceramic on polyethylene (CoP). We retrospectively reviewed selected 126 patients (252 hips) with bilateral THA (one ceramic-ceramic, AL/AL and the contralateral ceramic-polyethylene, AL/PE) who had THA performed between from 1981 to 1985 for osteonecrosis. Surgery was performed in patients who were average 50 years (range 30–60) old. The stem was always cemented and the same for both sides. The alumina head was 32 mm in diameter. The acetabular component was a polyethylene cup or an alumina cup and was always cemented. The mean follow-up for living patients was 35 years (range 32 to 36), and the mean follow-up for patients who had died was 23 years range 15 to 30). 14 periprosthetic fractures occurred in 252 hips after THA, representing an overall prevalence of 5.5% for hips and 11% for patients. Periprosthetic fractures increased in number with followup: 3 patients (3%) sustained fractures within 10 years of their primary implantation, 7 within 20 years, 10 within 30 years, 14 (11%) within 35 years. The risk of fracture was influenced (p=0.01) by the bearing surfaces at the time of prosthetic implantation, low (1%) for ceramic on ceramic (1/14 fractures; 1/126 hips), higher (10%) for ceramic on PE (13/14; 13/126). When the contralateral hip of the same patient is the control, the long-term risk of periprosthetic fracture on the side with PE cup is greater (10%) than on the side with ceramic/ceramic bearing

Previous studies have highlighted differences in the risk of periprosthetic fracture between tapered slip (TS) and composite beam (CB) stems. This biomechanical study explored periprosthetic fractures around these stems and the effect of adding a 16-gauge calcar or diaphyseal wire to TS stems on their resistance to torque.

A power analysis determined a sample size of 7 specimens per group, assuming a standard deviation of 14.8 Nm in peak torque, to provide 90% power to detect a difference of at least 30 Nm between groups. Twenty-one TS stems (eight alone, six with calcar wiring, seven with diaphyseal wiring placed 2 cm distal to the lesser trochanter) and seven CB stems were cemented into standard Sawbones. A servo-hydraulic test machine applied a 1000 N load with a 1-degree rotation per second until failure. The peak torque at failure was measured, and the fracture location recorded. Comparisons were performed using two-sample t-tests.

CB stems exhibited a significantly higher peak torque at failure (205.3 Nm) than TS stems (159.5 Nm, p=0.020). Calcar-wire-TS (148.2 Nm, p=0.036) and diaphyseal-wire-TS (164.9 Nm, p=0.036) were both weaker than CB stems. Wired-TS stems showed no significant difference from non-wired-TS stems. Additionally, the study could not conclude that calcar wiring is stronger than diaphyseal wiring. All TS fractures occurred at the mid-stem, simulating a B-type fracture, while the addition of the diaphyseal wire shifted the fracture location more distally in four of seven stems (p=0.0699).

This biomechanical study supports the clinical evidence that CB stems have stronger resistance to torque than TS stems and may explain lower risk of periprosthetic fracture. The addition of calcar or diaphyseal wires to TS stems resulted in no significant changes in peak torque to fracture. In patients at high risk of periprosthetic fracture, CB cemented stems should be considered.

Purpose. The purpose of this study was to evaluate the results of modular revision stems, uncemented fluted, tapered to treat periprosthetic femoral (PFF) fracture; we specifically evaluated fracture union, implant stability, patient outcomes, and complications to compare the differences between cemented and cementless primary stem. Materials and Methods. We retrospectively reviewed 56 cases of unstable periporsthetic femoral fracture (forty B2 and sixteen B3) treated with the uncemented fluted and tapered modular distal fixation stem with or with or without autogenous bone graft. Clinical outcomes were assessed with Harris Hip Score and WOMAC score. Radiologic evaluations were conducted using Beals and Tower's criteria. Any complication during the follow-up period was recorded. Results. The average follow-up period was 52.1±32.7 months. The average Harris Hip Score was 72.4±19.1. All fractures were united, and a good consolidation was achieved in 47 cases. There was femoral stem subsidence in 3 cases less than 10 mm without an evidence of loosening both radiologically and clinically. The radiologic results using Beals and Towers’ criteria were excellent in 36 hips, good in 10 hips and poor in 10 hips. Radiologic bone union took longer time and statistically significant stem subsidence was observed in cemented primary stem compared to cementless primary stem (Fig1,2). At each follow-up examination the clinical score was significantly higher in patients with cementless primary stem. Conclusion. Our results support the view that cement primary stem has less favorable result in terms of revision arthroplasty for periprosthetic femoral fractures

The stem design in total hip arthroplasty (THA) is constantly evolving. The impact of the collar on the risk of periprosthetic fracture remains controversial. This study aimed to determine whether adding a collar to the femoral stem impacts the early periprosthetic fracture risk within 90 days of surgery. This retrospective study included 1,623 patients who underwent primary total hip arthroplasty in a single orthopedic department between January 2010 and December 2020. The inclusion criteria were uncemented stem with or without a collar, in a primary intention, without previous hip surgery with a similar “corail like” design. The assessed data were demographic characteristics (age, gender, number of obese (BMI > 30)), single or dual mobility, the surgical approach, the early complication, particularly the periprosthetic femoral fractures. Of the 1,623 patients, 1,380 received a collared stem (85%), and 243 received a collarless stem (15%). A multivariate analysis was performed to determine the collar's effect on the risk of early periprosthetic fracture (<90 days). Nine (0.55%) early periprosthetic fractures were identified in the whole cohort. There were four fractures (1.65%) in the collarless stem group and five fractures (0.36%) in the collared stem group (p=0,005). One patient required revision surgery in the collared stem group, while two patients required revision surgery in the collarless stem group. The multinomial logistic regression model indicated a statistically significant lower (p<0.05) risk of early periprosthetic fracture within 90 days of surgery in the collared stems group. No other risk factor for early periprosthetic fractures has been identified. Using collared stems in cementless THA protects early periprosthetic femoral fractures within 90 days of surgery

Periprosthetic femoral fractures are increasingly seen in recent years, adding considerable burden to the National Health Service. These require complex revision or fixation and prolonged post-operative care, with significant morbidity with associated costs. The purpose of this study was to assess whether the size of femoral cement mantle is associated with periprosthetic femoral fractures (PPF). This retrospective study was carried out on a cohort of 49 patients (Fracture Group - FG) who previously had a revision procedure following a proximal PPF between 2010 and 2021. Inclusion criteria – all primary cemented total hip replacements (THR). Exclusion criteria – complex primary THR, any implant malposition that required early revision surgery or any pre-fracture stem loosening. The antero-posterior (AP) radiographs from this cohort of patients were assessed and compared to an age, sex, time since THR-matched control group of 49 patients without PPF (Control Group - CG). Distal cement mantle area (DCMA) was calculated on an AP radiograph of hip; the position of the femoral stem tip prior to fracture was also recorded: valgus, varus or central. Limitations: AP radiographs only. Statistical analyses were performed using Microsoft® Excel. Chi-square test demonstrated statistically significant difference in DCMA between FG and CG. DCMA of 700 to 900 mm² appeared to be protective when compared to DCMA of 0 to 300 mm². Also, a valgus position observed in 23% in FG Vs 4 % in CG increased the risk, with a smaller area of DCMA. This study demonstrates and recommends that a size of 700 – 900 mm² of the DCMA is protective against periprosthetic fractures, which are further influenced by the positioning of the distal stem tip. This could be due to the gradual decrease in the stiffness gradient from proximal to distal around the stem tip than steep changes, thereby decreasing possibility of a stress riser just distal to the cement mantle or restrictor. Further biomechanical research specific to this finding may be helpful to validate the observation, progressing to suggest a safe standardised surgical technique