Mitigating calcar fracture risk with automated impaction during total hip arthroplasty.

Background: Automated broaching has recently been introduced for total hip arthroplasty (THA), with the goal of improving surgical efficiency and reducing surgeon workload. While studies have suggested that this technique may improve femoral sizing and alignment, little has been published regarding its safety, particularly with regard to calcar fractures. The purpose of our study was to evaluate the risk of calcar fracture during automated broaching, and to determine if this risk can be mitigated. Methods: We queried our prospective institutional database and identified 1596 unilateral THAs performed by the senior author using automated impaction between 2019 and 2023. We identified the incidence of calcar fracture with automated impaction, and whether the fracture occurred during broaching or stem insertion. We additionally determined calcar fracture incidence within two consecutive subgroups of patients using different stem insertion techniques; subgroup (1): automated broaching with automated stem insertion for all patients; versus subgroup (2): automated broaching with automated stem insertion ONLY if a cushion of cancellous bone separated the broach from the calcar, otherwise the stem was placed manually. Continuous and categorical variables were analyzed with Student's t-test and Fisher's exact test, respectively. Results: Seventeen calcar fractures occurred intraoperatively (1.1 %). Only two fractures occurred during automated broaching (0.1 %), while fifteen occurred during final stem impaction (0.9 %) (p = 0.007). Four calcar fractures (1.4 %) occurred in subgroup 1, compared to two in subgroup 2 (0.6 %) (p = 0.28). Conclusions: Our study found a calcar fracture incidence of 1.1 % using automated impaction, consistent with historically reported rates of 0.4-3.7 %. We found that calcar fractures are more likely to occur during stem insertion than during femoral broaching. We recommend that if any part of the final broach is in direct contact with the calcar, the final stem should be impacted manually to minimize fracture risk.

Identification of Essential Features in Developing a Novel Femoral Stem Reflecting Anatomical Features of East Asian Population: A Morphological Study.

Background: Recent advancements in hip arthroplasty aim to enhance the stability, longevity, and functionality of femoral implants. However, the distal fitting of femoral stems, often caused by metaphyseal-diaphyseal mismatch, remains a significant issue, particularly in patients with Dorr type A femora. Such mismatches can result in suboptimal implant performance, leading to potential complications. This study focuses on evaluating the anatomical compatibility of five representative single-tapered wedge mid-short stems with the mediolateral (ML) anatomy of the proximal femur in an East Asian population, where these mismatches are often more pronounced. Methods: A total of 742 patients from two hospitals, all of whom underwent unilateral primary total hip arthroplasty, were included in the study. The contralateral proximal femur was confirmed to have normal anatomy in each patient. Hip anteroposterior radiographs were used for measurements, which were standardized in conjunction with CT images. Key anatomical parameters were measured, including proximal and distal medial-lateral canal dimensions, vertical offset, and medial offset. Five femoral stem designs-Tri-lock®, Taperloc®, Anthology®, Accolade II®, and Fit®-were evaluated. R programming was employed for a detailed fit analysis to match stem sizes with patient anatomy, categorizing the fit as proximal, simultaneous proximal-distal, or distal engagement. Results: Among the femoral stems analyzed, the Fit® stem demonstrated the closest alignment with the regression line for ML widths in the study population (slope = 0.69; population ML slope = 0.38). This was followed by Accolade II®, which had a slope of 0.83. In terms of offset options, the Accolade II® offered the largest offset coverage, making it particularly suitable for this population. The fit analysis revealed that the Fit® stem had the highest suitable fit rate (90.56%), followed by Accolade II® (73.04%). Taperloc®, Anthology®, and Tri-lock® had similar fit rates of approximately 59%. Overall, optimal results were obtained for 92.05% of the population in the automated fitting trial, regardless of the product type. Conclusions: When designing modern cementless femoral stems intended for press-fit fixation, it is crucial to account for the anatomical variations specific to the target population. In this study, Fit® and Accolade II® femoral components demonstrated superior compatibility with the femoral anatomy of the East Asian population, particularly in those with a higher incidence of Dorr type A femora. These stems, characterized by slimmer distal dimensions and high-offset options, appear to minimize metaphyseal-diaphyseal mismatch and associated complications.

Hip arthroplasty following failure of internal fixation in intertrochanteric femoral fractures: classification decision-making for femoral stem selection and clinical validation.

AIMS: Following Failed Internal Fixation of Intertrochanteric Fractures (FIF-ITF), the choice of treatment remains a clinical challenge. This study introduces a novel classification system to guide the selection of femoral prostheses in hip arthroplasty (HA) and validates its clinical efficacy. METHODS: Retrospectively, we analyzed 108 cases from three university-affiliated hospitals between December 2012 and February 2023 involving patients who underwent hip arthroplasty due to Failed Internal Fixation of Intertrochanteric Fractures (FIF-ITF). Patients were classified into three categories based on fracture healing, proximal femoral support, and the severity of femoral cortical defects, with subtypes identified. Surgical outcomes and complication rates were compared between the Classification-based Decision Group and the Non-classification Decision Group. RESULTS: The Classification-based Decision Group did not differ significantly from the Non-classification Decision Group in operation time, blood loss, or the use of cemented stems. However, the classification system markedly reduced the risk of periprosthetic fractures intraoperatively from 22.5 to 4.4% and postoperatively from 10 to 1.4%. The Classification-based Decision Group also demonstrated higher postoperative Harris Hip Score (HHS) and Visual Analog Scale (VAS) scores. CONCLUSION: The proposed classification system serves as an innovative clinical tool for femoral prosthesis selection in hip arthroplasty post-FIF-ITF, effectively reducing complications and enhancing hip function in the Classification-based Decision Group, underscoring its significant clinical utility.

Optimization Design and SLM Manufacturing of Porous Titanium Alloy Femoral Stem.

In order to solve the loosening problem caused by stress shielding of femoral stem prostheses in clinical practice, an optimization design method of a personalized porous titanium alloy femoral stem is proposed. According to the stress characteristics of the femur, the porous unit cell structures (TO-C, TO-T, TO-B) under three different loads of compression, torsion, and bending were designed by topology optimization. The mechanical properties and permeability of different structures were studied. Combined with the porous structure optimization, a personalized radial gradient porous titanium alloy femoral stem was designed and manufactured by selective laser melting (SLM) technology. The results show that the TO-B structure has the best comprehensive performance among the three topologically optimized porous types, which is suitable for the porous filling structure of the femoral stem, and the SLM-formed porous femoral stem has good quality. The feasibility of the personalized design and manufacture of porous titanium alloy implants is verified, which can provide a theoretical basis for the optimal design of implants in different parts.

Fracture of an Exeter Femoral Stem With Extensive Ipsilateral Periacetabular Osteolysis.

The Stryker Exeter stem (Stryker, Kalamazoo, MI) has been in service for over 50 years and remains the most widely used cemented stem. Stem fracture is a rare complication, with recently reported rates of 1 in 10,000. We present a case of Exeter stem fracture 25 years following initial implantation as well as a large periacetabular defect secondary to osteolysis. A revision total hip arthroplasty was performed, including periacetabular bone grafting for extensive osteolysis along with retention of a stable acetabular component. This case highlights the rare complication of Exeter stem fracture as well as the technique of bone grafting a large periacetabular defect with a retained acetabular component. This is of particular interest given the rarity of this event and the resurgence in North America of cemented femoral components in total hip arthroplasty.

Comparison of mid-term clinical and radiological results of short and conventional femoral stems in total hip arthroplasty.

This study aims to answer the question: Which are superior-conventional or short femoral stems?. An Optymis stem was used as a short-femoral stem, and an Accolade II stem was used as a conventional-femoral stem. There were 95 patients in the short femoral stem group (Group 1) and 90 in the conventional stem group (Group 2). The SF-36 Life Quality Score, thigh pain, and the Harris Hip Score were used to evaluate the patients' clinical outcomes. Pre-operative, immediate post-operative, and final follow-up x-rays were used for radiological evaluation. Stem varus/valgus alignment, hip offset changing, acetabular anteversion/inclination changing, femoral migration, acetabular migration, periarticular ossification, and osteointegration evaluation were assessed for both groups. The mean follow-up time was 5.5 years for Group 1 and 5.2 years for Group 2. No significant difference existed between the two groups in terms of clinical scores (Harris Hip Score, SF-36). Thigh pain was significantly higher in Group 2 (p = 0.0001). As for radiological parameters, Group 1 exhibited more varus position-related results. In terms of angular stability, Group 1 was found to be more unstable than Group 2 (p = 0.0001). The power to reconstruct femoral offset was superior in Group 1. Periarticular ossification was more frequent in Group 2. Femoral osteointegration was denser proximally in Group 1 and distally in Group 2. When mid-term radiological and clinical results of both femoral stems are evaluated, they have no superiority over each other.

Monte Carlo-based in-depth morphological analysis of medullary cavity for designing personalized femoral stem.

Background: The design of femoral stem prostheses requires a precise understanding of the femoral marrow cavity. Traditional measurements of morphological parameters in the upper femur, particularly the medullary cavity and cortical region, are primarily based on coronal and sagittal axes, which may not fully capture the true three-dimensional structure of the femur. Methods: Propose a Monte Carlo-based method for a more comprehensive analysis of the femoral marrow cavity, using CT scans of femurs from a selected group of patients. The study aimed to define and calculate anatomically semantic morphological parameters to enhance the understanding of the femoral marrow cavity's anatomical morphological changes, ultimately improving the design and clinical selection of femoral stem prostheses. To enhance the accuracy of femoral stem prosthesis design, this study aims to develop a Monte Carlo-based method for a more comprehensive analysis of the femoral marrow cavity. The proposed method transforms the non-random problem of determining cross-sectional size into a random issue, allowing for the calculation of the size of the medullary cavity and cortical region. Anatomically semantic morphological parameters are then defined, calculated, and analyzed. Results: The experimental results indicate that the newly defined parameters complement existing ones, providing a more rational scientific basis for understanding the anatomical morphological changes of the femoral marrow cavity. Conclusion: This research offers essential scientific theoretical support for improved morphologic research, design, and clinical selection of femoral stem prostheses. It holds significant importance and application value in clinical practice, contributing to a more accurate and comprehensive understanding of femoral anatomy for prosthetic design.

A Rare Case of Periprosthetic Fracture with Fracture of Femoral Stem around a Bipolar Hemiarthroplasty.

Introduction: The incidence of periprosthetic fractures (PPF) around a total hip arthroplasty continues to increase with the rise in number of arthroplasties performed. However, fracture of the femoral stem has become very rare since the development of modern prosthetic designs. We present a rare case of an 80-year-old man who sustained a periprosthetic femur fracture with a fracture of the femoral stem component around a bipolar hemiarthroplasty. Case Report: This man sustained a Vancouver type B1 periprosthetic femur fracture with a fracture of the femoral stem component around a fully cemented bipolar hemiarthroplasty done 10 years back. This patient was treated with removal of the broken femoral stem and osteosynthesis with a plate and cerclage wire plus revision to a longer stem prosthesis. Conclusion: PPF with a fracture of the femoral stem around a hemiarthroplasty is a rare and uncommon occurrence. A combination of osteosynthesis with revision arthroplasty with a longer stem proved to be a suitable treatment with satisfactory results. However, regular follow-ups post-arthroplasties are advocated to identify complications at an earlier stage.

Total Hip Arthroplasty with Extra-small Femoral Stems in Extremely Hypoplastic Femurs: A Case-Series Study.

Background: Total hip arthroplasty (THA) in patients with hypoplastic femurs presents a significant challenge to orthopedic surgeons due to the limited space available for implant placement. Therefore, the extra-small femoral stems have been proposed as a solution to this problem, but there are limited data on the outcomes. We aimed to evaluate clinical and radiological outcomes of THA in patients with extremely hypoplastic femurs using the Bencox CM stem (Corentec), an extra-small femoral stem. Methods: We included 6 hips from 4 patients. The mean age of the patients was 41.2 years (range, 19.6-60.4 years). The mean height was 135.1 cm (range, 113.6-150.0 cm) with a mean body mass index of 25.7 kg/m2 (range, 21.3-31.1 kg/m2). The diagnoses for THA were sequelae of septic arthritis in childhood, pseudoachondroplasia, spondyloepiphyseal dysplasia, and juvenile rheumatoid arthritis. Preoperative computed tomography scans were conducted to assess the extent of proximal femoral hypoplasia. The clinical outcomes were assessed using the modified Harris Hip Score, while the radiological outcomes were evaluated using radiographs. The mean follow-up was 2.3 years (range, 1.0-5.9 years). Results: The average modified Harris Hip Score improved to 88.8 at the final follow-up. Intraoperative femoral fractures occurred in 2 cases (33.3%). During the follow-up, 1 stem underwent varus tilting from postoperative 6 weeks to 6 months without subsidence. Otherwise, all stems showed good osteointegration at the latest follow-up. No hip dislocations, periprosthetic joint infection, or loosening of the prosthesis occurred. Conclusions: The use of extra-small femoral stems in THA for extremely hypoplastic femurs can provide reasonable clinical and radiological outcomes with minimal complications. We suggest that this femoral stem could be a viable option for patients with extremely hypoplastic femurs.

Callus formation after total hip arthroplasty using a short tapered-wedge stem.

OBJECTIVE: The incidence of periprosthetic fractures after total hip arthroplasty using a short tapered-wedge stem is high. Callus formation preceding this fracture, which indicates postoperative stress fracture around the stem, has been reported. However, previous studies on postoperative callus are limited. Hence, the current study aimed to evaluate the prevalence and risk factors of postoperative callus after total hip arthroplasty with a short tapered-wedge stem. MATERIALS AND METHODS: This retrospective study included 127 patients who underwent total hip arthroplasty using a cementless short tapered-wedge stem. The depth of stem insertion was measured as the distance from the lateral corner of the stem to the most medial point of the lesser trochanter along the body axis. Postoperative callus was defined as a bridging callus on the lateral femoral cortex at the distal end of the porous coating of the stem. Plain radiography was performed before surgery and immediately and at 1, 3, and 6 months after surgery to assess postoperative callus. Univariate and multivariate logistic regression analyses were performed to identify the risk factors for PC. RESULTS: In total, 60 (47.2%) of 127 patients presented with postoperative callus. Multivariate logistic regression analysis with postoperative callus as the dependent variable revealed that the stem depth at 1 month after total hip arthroplasty (odds ratio, 1.14; 95% confidence interval, 1.04-1.24, p = 0.002) was a significant and independent risk factor of postoperative callus. CONCLUSION: Deep insertion of a short tapered-wedge stem is a risk factor for postoperative callus.

Increased stability of short femoral stem through customized distribution of coefficient of friction in porous coating.

Stress shielding and aseptic loosening are complications of short stem total hip arthroplasty, which may lead to hardware failure. Stems with increased porosity toward the distal end were discovered to be effective in reducing stress shielding, however, there is a lack of research on optimized porous distribution in stem's coating. This study aimed to optimize the distribution of the coefficient of friction of a metaphyseal femoral stem, aiming for reducing stress shielding in the proximal area. A finite element analysis model of an implanted, titanium alloy short-tapered wedge stem featuring a porous coating made of titanium was designed to simulate a static structural analysis of the femoral stem's behavior under axial loading in Analysis System Mechanical Software. For computational feasibility, 500 combinations of coefficients of friction were randomly sampled. Increased strains in proximal femur were found in 8.4% of the models, which had decreased coefficients of friction in middle medial areas of porous coating and increased in lateral proximal and lateral and medial distal areas. This study reported the importance of the interface between bone and middle medial and distal lateral areas of the porous coating in influencing the biomechanical behavior of the proximal femur, and potentially reducing stress shielding.

3-D finite element model of the impaction of a press-fitted femoral stem under various biomechanical environments.

BACKGROUND: Uncemented femoral stem insertion into the bone is achieved by applying successive impacts on an inserter tool called "ancillary". Impact analysis has shown to be a promising technique to monitor the implant insertion and to improve its primary stability. METHOD: This study aims to provide a better understanding of the dynamic phenomena occurring between the hammer, the ancillary, the implant and the bone during femoral stem insertion, to validate the use of impact analyses for implant insertion monitoring. A dynamic 3-D finite element model of the femoral stem insertion via an impaction protocol is proposed. The influence of the trabecular bone Young's modulus (Et), the interference fit (IF), the friction coefficient at the bone-implant interface (µ) and the impact velocity (v0) on the implant insertion and on the impact force signal is evaluated. RESULTS: For all configurations, a decrease of the time difference between the two first peaks of the impact force signal is observed throughout the femoral stem insertion, up to a threshold value of 0.23 ms. The number of impacts required to reach this value depends on Et, v0 and IF and varies between 3 and 8 for the set of parameters considered herein. The bone-implant contact ratio reached after ten impacts varies between 60% and 98%, increases as a function of v0 and decreases as a function of IF, µ and Et. CONCLUSION: This study confirms the potential of an impact analyses-based method to monitor implant insertion and to retrieve bone-implant contact properties.

Mid-term results of titanium-titanium modular neck femoral stem in primary total hip arthroplasty.

BACKGROUND: Modular neck femoral stems are advantageous because they can accurately restore the ideal hip geometry using various options in terms of offset, length, and version. However, there are concerns regarding junctional problems. Despite several reports on such issues, there is a lack of study on mid- to long-term results of these stems. The current study evaluated the mid-term results of patients who underwent primary total hip arthroplasty using a titanium-titanium (Ti-Ti) modular neck femoral stem. METHODS: In total, data on 47 hips (42 patients) that could be followed-up for ≥ 5 years after primary total hip arthroplasty using the Ti-Ti modular neck femoral stem from 2011 to 2015 were reviewed. There were 22 male and 20 female patients, and their mean age was 56.3 (range: 31-76) years. The mean follow-up period was 8 (range: 5-12) years. Functional and radiological outcomes, complications, and reoperations were investigated. In addition, we conducted a comparative analysis of the outcomes between those who underwent surgery using the Ti-Ti modular neck femoral stem and 41 hips (35 patients, 19 males and 16 females) that underwent primary total hip arthroplasty using nonmodular femoral stems as a control. RESULTS: In all Ti-Ti cases, the mean Harris Hip Scores were 50.6 (range: 6-59) preoperatively and 92.7 (range: 78-99) at the last follow-up (P < 0.001). Regarding the neck component's modularity, straight neck components were used in all Ti-Ti cases, and an anteverted or a retroverted neck was not used in any case. Stem revision was performed in one hip due to aseptic loosening. One hip underwent open reduction and internal fixation due to periprosthetic fracture without stem loosening. There were no cases of osteolysis and periprosthetic joint infection and clinically detectable junctional problems. The stem survival rate, with any stem revision as the endpoint, at 12 years was 96.6%. No significant difference was observed in the functional and radiological outcomes beween the Ti-Ti and nonmodular groups. CONCLUSIONS: The Ti-Ti modular neck femoral stem had comparable results with broadly used nonmodular femoral stems; hence, it can be a reliable option in primary total hip arthroplasty. However, in terms of the modularity itself of the modular neck femoral stem, whether the modular neck femoral stem is useful in uncomplicated primary total hip arthroplasty is unclear.

Mid-term survival of the Optimys short stem: A prospective case series of 500 patients.

BACKGROUND: In recent years, there has been an increase in the number of total hip arthroplasty procedures in the younger patient population. This active group has higher expectations of their prosthesis in comparison to the older population, and there is a greater physical demand for the prosthesis. Short femoral stems were introduced to retain proximal bone stock and joint biomechanics and became more common to implant in this specific population. Currently, the long-term survival and functional outcomes of various short stems are still being investigated in different clinics. AIM: To determine the 5-year survival of the Optimys hip stem. METHODS: This was a prospective multicenter cohort study of 500 patients conducted in two hospitals in the Netherlands. All patients received the Optimys short stem (Mathys Ltd, Bettlach, Switzerland). The primary outcome measure was survival of the hip stem, with revision as the endpoint. The secondary outcome measurements included patient-reported outcome measures (PROMs). Kaplan-Meier analysis was used to calculate the 5-year survival rate. Log-minus-log transformation was performed to calculate the 95% confidence interval (95%CI). Mixed model analyses were performed to assess the course of the PROMs during the 1st 2 years after surgery. Analyses were modeled separately for the 1st and 2nd years to calculate the yearly change in PROMs during both follow-up periods with accompanying 95%CIs. RESULTS: The mean age of the total 500 patients was 62.3 years (standard deviation: 10.6) and 202 were male (40%). At a median follow-up of 5.5 years (interquartile range: 4.5-6.7), 7 patients were deceased and 6 revisions were registered, for infection (n = 3), subsidence (n = 2) and malposition (n = 1). This resulted in an overall 5-year survival of 98.8% (95%CI: 97.3-99.5). If infection was left out as reason for revision, a stem survival of 99.4% (95%CI: 98.1-99.8) was seen. Baseline questionnaires were completed by 471 patients (94%), 317 patients (63%) completed the 1-year follow-up questionnaires and 233 patients (47%) completed the 2-year follow-up. Both outcome measures significantly improved across all domains in the 1st year after the operation (P < 0.03 for all domains). In the 2nd year after surgery, no significant changes were observed in any domain in comparison to the 1-year follow-up. CONCLUSION: The Optimys stem has a 5-year survival of 98.8%. Patient-reported outcome measures increased significantly in the 1st postoperative year with stabilization at the 2-year follow-up.

15-year survivorship of a unique dual-modular femoral stem in primary hip arthroplasty.

BACKGROUND: Hip offset, version, and length are interdependent femoral variables which determine stability and leg length. Balancing these competing variables remains a core challenge in hip arthroplasty. The potential benefits of modular femoral stems have been overshadowed by higher rates of failure. The objective of this study was to assess the survivorship of a unique dual-modular femoral stem at an average 15-year follow-up period. METHODS: The records of all patients with osteoarthritis who underwent primary total hip arthroplasty with this device between 2004-2009 were reviewed. There were no exclusions for BMI or other factors. We examined the data with Kaplan-Meier survival analysis. The primary endpoint for survival was mechanical failure of the modular neck-body junction. RESULTS: The survivorship of this device in 172 subjects was 100% with none experiencing mechanical failure of the modular junction at an average of 15 years. 60 patients died of causes unrelated to their THA and 9 patients were lost to follow-up. There were three early (≤ 12 months) dislocations (1.7%), and seven total dislocations (4.1%). 16 patients underwent reoperations during the follow-up period, none for any complication of the modular junction. Radiographic results showed well-fixed femoral stems in all cases. There were no leg length discrepancies of greater than 10 mm, and 85% were within 5 mm. CONCLUSION: There were no mechanical failures of the modular junction in any of the subjects over the average 15-year period, demonstrating that this dual-modular design is not associated with increased failure rates. We achieved a 1.7% early dislocation rate and a 4.1% total dislocation rate without any clinically significant leg length discrepancies.

Durability of Primary Total Hip Arthroplasty With Cementless Stems Without a Collar in Elderly Patients Age 75 Years and Over.

BACKGROUND: Cementless femoral fixation in total hip arthroplasty (THA) has increased in prevalence worldwide. However, cementless fixation in elderly patients is controversial due to the risks of periprosthetic fracture and aseptic loosening. This study evaluated outcomes in patients undergoing primary THA utilizing a cementless stem without a collar, comparing those less than 75 years to those older than 75 years. METHODS: Between 2011 and 2021, there were 2,605 cementless THAs performed by 4 surgeons utilizing a highly porous metal fixation surface without a collar and consistent clinical protocols. There were 469 patients who had an age ≥ 75 years. Revision rates, intraoperative fractures, and 90-day mortality were compared between cohorts. In the ≥ 75 year age group, there were more women, more American Society of Anesthesiologists physical status classification III or IV, a lower body mass index, and more kidney disease, osteoporosis, and thyroid disease (P ≤ .002). RESULTS: All-cause revision rates trended lower for the ≥75 year age group compared to < 75 year (1.9 versus 3.5%, P = .082) at 20-months of follow-up. Moreover, there was no difference in all-cause femoral component revisions comparing ≥ 75 to < 75 year age groups (1.5 versus 2.2%, P = .375), with only 3 of 10 femoral revisions due to aseptic loosening being in the ≥ 75 year age group. Intraoperative fracture (0.2 versus 0.5%, P = .701) and 90-day mortality (0.2 versus 0.1%, P = .460) did not differ between ≥ 75 and < 75 year age groups. CONCLUSIONS: Older patients had comparable revision rates compared to younger patients using cementless femoral fixation without a collar. Furthermore, there was no difference in 90-day mortality or intraoperative fracture rates. Study findings provide evidence for the safety and durability of cementless THA using collarless femoral stems in elderly patients ≥ 75 years of age. LEVEL OF EVIDENCE: III.

Use of a Trephine to Extract a Fractured Corail Femoral Stem During Revision Total Hip Arthroplasty: Tips From Our Case Report.

Despite the significant advancements in the field of total hip arthroplasty (THA) and prosthesis designs, fracture of the modular femoral stem after THA can occur rarely and needs attention. Orthopaedic surgeons face a daunting task when it comes to the removal of a broken stem. The use of a trephine reamer has been evaluated for extracting the distal femoral stem, and this case report tries to address some key tips for the same. A 67-year-old obese male, without any major medical comorbidities, presented to the Royal Lancaster Infirmary orthopaedic outpatient department with a complaint of acute-on-chronic right anterior thigh pain that worsened over a few weeks. He had a history of bilateral staged uncemented THA done around 12 years ago. The plain radiological images confirmed the presence of a fracture of the Corail femoral stem. A posterior approach was used to dislocate the hip and the distal broken part of the stem was removed using trephines. Reamers were used and care was taken to prevent thermal necrosis by using intermittent saline lavage. After the removal of the fractured femoral stem, a cemented femoral revision THA was performed, which was uneventful. The patient walked without any aid or thigh pain postoperatively during his last follow-up. Using trephines to remove broken femoral stems is an effective and safe method. Intraoperative measures can help in avoiding heat necrosis while using a trephine reamer for extracting the fractured femoral stem. Regular follow-up and counselling are important after THA, to avoid a delayed diagnosis of non-traumatic femoral stem fractures.

Slightly reduced early subsidence with similar outcomes and complications rate in collared stems - A systematic review of randomized clinical trials.

Background: There is a growing trend towards using femoral stems with a medial calcar collar during total hip arthroplasty (THA). Purpose: Systematically review the literature comparing a femoral collared stem and femoral collarless stem on subsidence, patient-reported outcomes (PROs), and revision rate. Study design: Systematic Review, Level of Evidence 1. Methods: A literature search of Pubmed and Medline was according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized controlled trials that evaluated collared and collarless stems, subsidence and PROs for adult patients undergoing total hip arthroplasty (THA) were included. Additional data collection included patient demographics, stem-calcar contact, canal-fill ratio (CFR), stem orientation, surgical approach, Dorr Type, complications, and revisions. Results: Five studies met inclusion criteria. 674 patients (704 hips) were included. Mean patient ages ranged 58.5-72.4 years old, and mean BMI ranged 26.6-29.8 kg/m2. Mean reported follow-up of the included clinical trials ranged 1-9.6 years. Two studies reported mean early subsidence at two weeks postoperatively, which was 0.36, 0.99 mm for collared stems and 0.52, 3.22 mm for collarless stems, proving to be statistically significant (P = 0.023), (P = 0.05). All studies demonstrated improved PROs at most recent follow-up. Revision rates ranged from 4 to 11.3 %, but these were not statistically significant. Conclusions: Implantation of collared stems compared to collarless may reduce early post-operative subsidence, while no substantial effect on aseptic loosening, thigh pain, proximal femoral fracture, and revision is seen. When measuring patient-reported outcomes, the collared femoral stem was not superior to the collarless femoral stem as both resulted in similar improvement preoperatively to postoperative state.

Alignment and mechanics evaluation for a compaction broach stem versus a blade style proximal press fit stem using 3-Dimensional planning.

Three-dimensional (3D) preoperative planning tools can be used to help plan and compare component alignment scenarios for different total hip arthroplasty systems to ultimately improve postoperative outcomes and patient satisfaction. The objective of this study is to use 3D preoperative planning tools based on patient-specific bone models to compare two different stem designs, specifically a compaction broach stem and a proximal press fit stem. The planner uses patient-specific proximal femoral bone morphology to suggest a specific implant size and placement. The planner then allows for preoperative predictions of component head positioning, stem fit within the canal, and potential cortical bone reaming that must be done, as well as postoperative predictions of stability and mechanics. The stems were evaluated to determine the accuracy of stem placement, the theoretical volumetric bone removal/reaming required to achieve a desired fit, and the associated postoperative mechanics. This study demonstrated that there was a difference in component alignment and predicted postoperative mechanics between a compaction broach stem and a press fit stem, with the compaction broach stem allowing for more accurate alignment with less required bone removal, resulting in improved postoperative stability and mechanics. This study also demonstrated that much of the stem misalignment for both systems occurred in the anterior/posterior direction. Overall, 3D preoperative planning offers significant benefits and novel intraoperative insight, and the industry should continue to enhance their THA preoperative planning tools.