Femoral Stem Research Articles

Removal of Well Fixed, Fluted Cementless Femoral Stem. Revisiting The Antegrade Drilling Technique for Easier Stem Extraction.

Removal of Well Fixed, Fluted Cementless Femoral Stem. Revisiting The Antegrade Drilling Technique for Easier Stem Extraction.

The cemented stem in hip arthroplasty - state of the art technique and recommendations.

The indication for femoral stem cementation should be made on a patient-specific basis, taking physical activity, femoral geometry, and bone tissue quality into account. Age alone should not be the sole justification for cementation. The Dorr classification can serve as decision support for whether a cemented fixation should be used. Femoral neck fractures should generally be cemented. Familiarize yourself with the applied stem philosophy. Force-closed stems typically have a polished surface that allows for subsidence, especially in the first 2 years postoperatively. Stems following the shape-closed philosophy have rougher surfaces and do not allow subsidence. There are various types of cement that differ in viscosity and can be categorized accordingly. These cement types go through four temperature-dependent phases: mixing phase, waiting phase, working phase, and curing phase. Rough implants should be implanted quickly, using wetter cement. For a polished stem, the cement should be slightly firmer. To avoid complications like bone cement implantation syndrome, it is essential to adhere to the state-of-the-art retrograde cementation technique, which recommends pulsatile lavage and vacuum mixing of the cement. Additionally, cement restrictors and pressurizers are used. A thorough understanding of cementation techniques is crucial to ensure a favorable outcome with a uniformly thick cement mantle that encompasses the entire stem. Incorrect cementing can lead to the premature failure of the endoprosthesis.

[Translated article] Retrospective survival analysis of the use of uncemented modular tapered stems for revision in periprosthetic Vancouver B-type fractures. Is instability a threat to survival

Introduction and objectives: Periprosthetic hip fractures show increasing incidence and complexity, representing a challenge for the surgeon. We aimed to evaluate the survival of uncemented modular tapered stems in the treatment of periprosthetic Vancouver B2 and B3 type fractures and review the main complications and factors associated with decreased survival.Materials and methods: We performed a retrospective study of patients submitted to revision arthroplasty for treatment of periprosthetic femoral stem Vancouver B2 and B3 type fractures with an uncemented modular fluted tapered stem (MRP-Titan). Demographic and radiographic parameters were analyzed. The survival rate (free of reoperation) was calculated at 2- and 5-years using the Kaplan–Meier survivorship analysis.Results: Thirty-nine patients were included with a mean age of 73.5 years and a mean follow-up of 5 years. Arthroplasty survivorship at 2 years was 73.7% and at 5 years was 67.5% (mean 8.4 years; range 6.7–10.2). Survivorship was inferior in the patients with episodes of instability (mean 2.5 years; range 0–5.42) (p < 0.001). At least one episode of instability occurred in 26.3% of patients and 60% of these patients had a femoral head size 32 mm or lower. At least one episode of instability occurred in 71.4% of patients with a greater trochanter fracture (p = 0.008). The consolidation rate was 90.6% and the mortality rate was 23.7%. In the group of patients that died, 55.6% were submitted to at least one revision surgery (p = 0.044).Conclusion: Survivorship of an uncemented modular stem (MRP-Titan) in revision for PHF is significantly reduced by episodes of instability.

Is there a difference between modular versus monoblock femoral stem used during revision total hip arthroplasty?

Response/Recommendation The literature delineates distinct differences between modular and monoblock femoral stems in revision total hip arthroplasty (rTHA), each presenting unique advantages and limitations. Modular stems offer intraoperative flexibility, enabling precise restoration of leg length and offset. However, they are associated with complications such as junctional fatigue, corrosion, and implant breakage, and they incur much higher costs compared to monoblock stems. In contrast, monoblock stems provide enhanced mechanical stability and no risk of modular junction complications, though their implantation is technically more challenging. Both modular and monoblock femoral stem designs perform well in revision THA, exhibiting no significant differences in long-term (3-5 years) clinical outcomes or subsidence rates. The choice between modular and monoblock stems should be tailored to individual patient needs and specific clinical scenarios. LEVEL OF EVIDENCE: Moderate. DELEGATES VOTE: 92.7% Agree, 5.7% Disagree, 1.7% Abstain.

A Customized Distribution of the Coefficient of Friction of the Porous Coating in the Short Femoral Stem Reduces Stress Shielding

Stress shielding and aseptic loosening have been identified as adverse effects of short-stem total hip arthroplasty resulting in hardware failure. However, there is a gap in research regarding the impact of stress shielding in customized porous coatings. The purpose of this study was to optimize the distribution of the coefficients of friction in the porous coating of a metaphyseal femoral stem to minimize stress shielding. Static structural analysis of an implanted short, tapered-wedge stem with a titanium porous coating was performed with the use of Analysis System Mechanical Software under axial loading. To limit computational time, we randomly sampled only 500 of the possible combinations of coefficients of friction. Results indicate that the coefficient of friction in the distal lateral porous coating significantly affected the mid-distal medial femoral surface and lateral femoral surface. The resultant increased proximal strains resulted from an increased coefficient of friction in lateral porous coating and a reduction in the coefficient of friction in medial mid-distal coating. These findings suggest that a customized porous coating distribution may produce strain patterns that are biomechanically closer to intact bone, thereby reducing stress shielding in short femoral stems.

Influence of Femoral Stem Geometry on Total Hip Replacement: A Comparison of Clinical Outcomes of a Straight and an Anatomical Uncemented Stem.

Background/Objectives: There are many aspects that may influence clinical outcomes in a total hip arthroplasty (THA). The influence of femoral stem on the clinical outcome of THA is probably underestimated in the literature. Our work aims to analyze how uncemented stem geometry (straight or anatomical) in THA might affect outcomes in clinical and radiographic terms. Methods: Over a period of 36 months, in a prospective-observational manner, we collected the results of THA secondary to osteoarthritis (OA) that met the inclusion criteria with the only variable being the straight or anatomical stem design in a single manufacturer. A total of 84 patients were selected and divided into two groups: group A, treated with straight stem (44 patients), and group B, treated with anatomical stem (40 patients). The assessment clinical tools were Harris Hip Score (HHS), Visual Analogue Scale (VAS), and Short Form Health Survey-36 (SF-36). Follow-up controls were at 6 months (T0), 12 months (T1), 24 months (T2), and 36 months (T3). Results: No statistically significant differences emerged between the two groups under analysis with VAS, SF-36, and HHS. At follow-up controls, eight patients (group A) and four patients (group B) showed anterior thigh pain. At T1, there were radiographic signs of aseptic loosening in two cases (group A) and one case (group B). In group A there were two cases of iatrogenic fracture, two cases of dislocation, one case of infection, and two cases of heterotopic ossification. Conclusions: The anatomical stem compared to the straight stem showed lower complication rates outcomes; the anatomical uncemented stem could be considered as a preferred first choice in THA compared to the straight stem.

How does the position of the pelvis and femur influence the selection of prosthesis size during 2D preoperative planning for total hip arthroplasty?

PurposeTotal Hip Arthroplasty (THA) is the primary treatment for hip diseases today. Nevertheless, total hip arthroplasty has its challenges, and one of these challenges is the potential for incorrect execution of the preoperative planning process. Such errors can lead to complications such as loosening and instability of the prosthesis and leg length discrepancy. In this study, we used human phantoms to investigate the influence of pelvic and femoral factors on prosthesis size selection in the preoperative planning of total hip arthroplasty and to provide a reference standard for clinical imaging in preoperative planning of total hip arthroplasty.MethodsIn this experiment, we utilised a custom-made experimental device that enabled us to manipulate the movement of the pelvis and femur in various directions. The device also incorporated sensors to control the angle of movement. By obtaining X-rays from different positions and angles, we were able to determine the size of the prosthesis based on the 2D preoperative planning generated by the mediCAD software.ResultsWhen the pelvis was in a nonneutral position, the size of the acetabular cup varied within a range of three sizes. Similarly, when the femur was in a nonneutral position, the size of the femoral stem varied within a range of two sizes. The movement of the pelvis and femur in the coronal plane, relative to the neutral position, did not impact the selection of the prosthesis size. However, the motion of the pelvis and femur in the sagittal and transverse planes had a notable effect.ConclusionThe selection of the prosthesis size for preoperative planning can be significantly influenced by specific positions of the pelvis and femur. It is crucial for the radiographer to ensure that the pelvis and femur maintain a standard neutral position, particularly in the sagittal and transverse planes, during the image acquisition process.

Leg length discrepancy risk differs between fit-and-fill and taper wedge stems across Dorr types.

The comparison between the cementless taper wedge stem and fit-and-fill stem in total hip arthroplasty (THA) for various proximal femoral morphological types has not been thoroughly assessed. This study aimed to compare the risk of leg length discrepancy (LLD) ≥ 10mm between these two stem types in Dorr type A, B, and C femurs. From April 2015 through April 2021, we analyzed 1178 unilateral primary cementless THA procedures. We categorized all procedures into three groups: Dorr type A (N = 220, 18.7%), B (N = 875, 74.3%), and C (N = 83, 7.0%). Within each Dorr type, we compared the incidence and risk of postoperative LLD ≥ 10mm between the two stem types. The factors considered in the multivariate regression analyses included stem type, age, sex, body mass index, diagnosis, canal flare index, femoral cortical index and stem alignment. The taper wedge stem group had a higher overall incidence of LLD ≥ 10mm (12.8% vs. 7.4%, P = 0.012) and in Dorr type A femurs (22.2% vs. 7.6%, P = 0.014), compared with the fit-and-fill stem group. In multivariate analysis, the taper wedge stem exhibited an increased risk of LLD ≥ 10mm only in Dorr type A femurs (aOR: 3.449, 95% CI: 1.325-8.794). The incidence and risk of LLD ≥ 10mm were not different between the two stems in Dorr type B and C femurs. The taper wedge stem demonstrated an elevated risk of LLD ≥ 10mm in Dorr type A femurs compared with the fit-and-fill stem, necessitating meticulous preoperative templating and intraoperative femoral canal preparation.

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

AimsFollowing 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.MethodsRetrospectively, 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.ResultsThe 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.ConclusionThe 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.

Influence of proximal femoral morphology on osteointegration of the AMIS uncemented femoral stem in modern hip arthroplasty

BackgroundIndications for total hip arthroplasty (THA) have evolved over recent decades, with a growing trend toward operating on younger and more active patients. With this shift in patient demographics, there has been a change in femoral stem designs and proximal femoral morphology encountered. This study aimed to evaluate the potential correlation between femoral stem osteointegration and proximal femoral morphology using the Dorr and Noble classifications.Materials and methodsWe conducted a retrospective review of 122 uncemented femoral stems (AMIstem Medacta, triple tapered). The demographic data analyzed included sex, age, stem size, and surgical indications. Preoperative radiographs were reviewed to determine the Dorr classification as well as the canal-to-calcar isthmus ratio, cortical index, and canal flare index. Postoperative radiographs were carefully reviewed to identify the presence of potential postoperative radiolucencies. Inter- and intra-observer agreements for these parameters were also analyzed.ResultsSignificant radiolucencies (> 2 mm) were found in 19.5% of the patients. Of all the variables analyzed, the cortical index was the only parameter significantly associated with the appearance of clinically significant radiolucency, with a threshold value of 0.62.ConclusionsThe appearance of radiolucencies is multi-factorial. Nevertheless, in this study, a high cortical index (> 0.62), representing the champagne flute morphology, was found to be associated with the development of significant radiolucencies.

SIMULTANEOUS VERSUS STAGED TOTAL HIP ARTHROPLASTY FOLLOWING ACETABULAR FRACTURE FIXATION: A COMPARISON OF OUTCOMES

Acetabular fractures present a challenge. Anatomical reduction can be achieved by open reduction and internal fixation (ORIF). However, in elderly patients with complex fracture patterns and osteoporotic bone stock, “fix and replace” has become an option in the management of these injuries. This involves ORIF of the acetabulum to enable insertion of a press fit cup and subsequent cemented femoral stem at the index surgery.A Retrospective analysis of all operatively managed acetabular fractures by a regional Pelvic and Acetabular Trauma service (01/01/2018-30/05/2023) STATA used for analysis. 34 patients undergoing “fix and replace” surgery. Of the 133 patients managed with ORIF, 21 subsequently required Total Hip Arthroplasty (THA). Mean follow up was 2.7 years versus 5.1. There was no statistical significance between the two groups with regards to BMI or sex. Mean age in the “fix and replace” group was 68 compared to 48 in the ORIF and subsequent THA group. This reached statistical significance between the two groups (p=0.001).ASA and Charlson Comorbidity Index (3 and 3 in “fix and replace” and 2 and 1.2 in ORIF to THA group) and Charlson Comorbidity Index both were statistically significantly different (p=0.006 and p=0.027, respectively). High energy mechanism of injury accounted for 56% of the “fix and replace” group compared to 48% in the ORIF to THA. 74% of “fix and replace” were associated fractures compared to 53% of ORIF to THA. Wait to surgery was 3 days for “fix and replace” while 186 days was the mean wait time from listing to THA for the ORIF to THA group. Complication rate was 41% versus 43% in the two groups. 14% in the ORIF to THA group developed PJI versus 6% in “fix and replace”.Fix and replace allows early mobilisation in frailer, elderly patients. Our results show fewer returns to theatre and less PJI in patients having arthroplasty as part of “fix and replace” than subsequent to Open reduction internal fixation.

THE X-RAY CALIBRATION PROJECT

Increasing the accuracy of information provided through X-Rays maximises pre-operative planning. Aim of this project is to determine the necessity of calibration probes that would improve the accuracy of pre-operative templating. This is a retrospective study involving leg length and pelvis X-Rays performed across the NHS Lanarkshire from 01/03/2023 until 31/04/2024.A total of 87 leg length X-Rays were identified, 18 had a calibration probe present. Leg length was measured on each and the X-Rays were calibrated against the existing probe. In 66.7% of cases there was a major leg length discrepancy of over 2cm between the pre-calibrated and post-calibrated X-Rays. Pelvic X-Rays of 80 patients that underwent total hip replacement were reviewed. Preoperative templating was compared to the implants inserted. An average of 1.94 discrepancy in the size of the acetabular implant was identified whilst in 30 cases the size of the femoral stem was incorrect by at least 1 size. Magnification of 119.7% on X-Rays was found to provide the most accurate templating. Seventy seven cases of pelvic X-Rays before and after hip hemiarthroplasty were also reviewed. The implant head was templated incorrectly in 74% of cases and the stem in 51%. It was identified that pelvic X-Ray magnification of 121.7% would provide the most accurate results.X-Rays with no calibration probes provide inaccurate measurements leading to faulty preoperative planning. Standardised use of a calibration sphere is strongly suggested and whenever that is not available, we suggest magnification of 121%.

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.

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.

Extended Trochanteric Osteotomy Does Not Compromise Functional and Radiographic Outcomes of Femoral Stem Revisions with the Use of an Uncemented Modular Conical Stem.

Background: Stem revisions in revision total hip arthroplasty (THA) with proximal bone stock loss may be dealt with utilizing modular, uncemented conical stems. During stem extraction, surgeons may resort to extended trochanteric osteotomy (ETO). However, ETO is associated with extensive blood loss and infections. This study compared the clinical outcomes, radiographic results and complications in THA revisions utilizing conical modular stem with and without ETO. Methods: Patients who underwent revision THA with or without ETO were assessed retrospectively. The minimal follow-up was 3 years. The functional evaluation included Harris Hip Score (HHS) and Short Form 36 (SF-36) as well as Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Numerical Rating Scale for pain assessment. The radiographic evaluation comprised bone defect assessment, osteotomy healing, stem migration and position, presence of radiolucent lines and stress shielding. Results: In total, 73 patients (80 hips) were included in the final analysis. The ETO group comprised 48 hips, and the no-ETO group comprised 32 hips. In the ETO group, pre-operative WOMAC scores were lower than in the no-ETO group (p = 0.012). No significant differences were found in terms of post-operative HHS, WOMAC, and NRS scores between groups, except worse results were found in the case of claw plate implantation. Patients in the no-ETO group exhibited better results in SF-36 than in the ETO-group. Osteotomy non-union was observed in four hips (9.5%). Stam varus/valgus position was within ±1.5 degrees (85.9%). Conclusions: ETO does not adversely impact outcomes in patients undergoing femoral stem revisions with modular conical stems. The invasive nature of these procedures prompts careful consideration in each case individually.

Does Femoral Stem Design Influence Periprosthetic Fracture Incidence and Morphology in Total Hip Arthroplasty?

BackgroundAs the incidence of total hip arthroplasty (THA) increases, the number of periprosthetic femur fractures (PFF) will also rise. The surgical approach and stem design have been shown to influence the rate of PFF. This study evaluated PFF in cementless THA done through the posterior approach and described how stem design influences intraoperative and early postoperative fracture incidence and morphology. MethodsA retrospective review of 3,183 primary THAs for osteoarthritis from 2013 to 2021 was performed. Demographics, comorbidities, femoral stem designs, intraoperative and early postoperative PFFs (< 90 days), and aseptic femoral revisions were recorded. Stems were classified as single-wedge taper (Type 1), double-wedge taper (Type 2), or ream and broach (Type 3). There were 1,192 Type 1, 240 Type 2, and 1,726 Type 3 femoral stems. The PFF and aseptic femoral revisions were compared with univariable and multivariable analyses. Cox regression and Kaplan-Meier analyses evaluated survival to femoral revision. ResultsIn this population, 25 patients (0.8%) had an intraoperative or early postoperative PFF. Patients who had PFFs were older (68 versus 63; P = 0.03) and more likely to be women (76 versus 24%; P = 0.02). Type 2 stems had a significantly higher incidence of all-cause PFFs when compared to Type 1 (3.6 versus 0.7%; P < 0.01) and Type 3 (3.6 versus 0.4%; P < 0.01) stems. Type 2 stems also had a higher incidence of Vancouver B2 PFFs when compared to Type 3 stems (0.8 versus 0.05%; P = 0.04). Stem design was not associated with PFF or all-cause femoral revision. There were no differences in survival to femoral revision. ConclusionDouble-wedge taper stems may be associated with increased intraoperative and early postoperative PFFs, including those requiring femoral stem revision. However, there was no statistically significant difference in late PFF, aseptic loosening, or femoral revision.

High preservation rates of the ascending branch of the lateral femoral circumflex artery during total hip arthroplasty through the direct anterior approach.

(i) To investigate the rate of preservation of the ascending branch of the lateral femoral circumflex artery (a-LFCA) during total hip arthroplasty (THA) through a direct anterior approach (DAA), and (ii) to study factors that contribute to its successful preservation. All patients who underwent primary THA between 1 September 2023 and 29 February 2024 were reviewed. One-hundred seventy-two patients were included in the study, 91 females and 81 males, aged 63.2 ± 12.6, with a body mass index of 26.1 ± 4.6 kg/m2. THA was performed through a minimally invasive DAA in all patients, using either a standard vertical DAA or a Bikini incision. Patients were stratified by the preservation of the a-LFCA (preserved, ligated/electrocauterized due to obstruction of the surgical field during dissection, electrocauterized due to bleeding during femoral broaching or stem insertion). Descriptive statistics were used to summarise the data. Logistic regression analyses were performed to explore possible factors associated with the preservation of a-LFCA. The a-LFCA was preserved in 130 patients (75.6%), had to be ligated/electrocauterized due to obstruction of the surgical field during dissection in 31 patients (18.0%), and had to be electrocauterized due to bleeding during femoral broaching or stem insertion in 11 patients (6.4%). Multivariable logistic regression analyses revealed that preservation of a-LFCA was significantly more likely in female patients (odds ratio [OR] = 2.22; 95% confidence interval [CI] = 1.1-4.6; p = 0.029), as well as in patients with younger age (OR = 0.97; 95% CI = 0.9-1.0; p = 0.036) and lower weight (OR = 0.97; 95% CI = 0.9-1.0; p = 0.005). Preservation of the a-LFCA is possible in the majority of patients (75.6%) undergoing THA through minimally invasive DAA. Furthermore, preservation of the a-LFCA is more likely in female patients, younger patients and patients with lower weight. Level IV.

Total hip arthroplasty for femoral fractures other than capital physeal fractures in dogs: 14 cases (2012-2020).

The goals of this retrospective study were to assess the clinical and radiographic outcomes in dogs with proximal femoral fractures, other than capital physeal fractures, treated via total hip arthroplasty. Medical records as well as pre-operative, immediate post-operative and 2 to 3 months post-operative radiographs of 14 dogs with femoral head and neck fractures treated via total hip arthroplasty were reviewed. A Liverpool Osteoarthritis in Dogs questionnaire was completed by owners to assess long-term outcomes. Seven femoral head fractures, and seven femoral neck fractures were included. Four of the femoral head fractures were acute in nature, the three remaining femoral head fractures and all seven femoral neck fracture cases were chronic fractures. Malorientation of the femoral stem was more common in the chronic femoral fracture cases when compared to the acute femoral fracture cases. Two of the acute fracture cases and five chronic fracture cases experienced a change in femoral stem position post-operatively. One femoral fissure fracture occurred and was repaired intraoperatively. One case had a post-operative complication that resulted in implant removal. All dogs had good to excellent owner-perceived outcome. Femoral head and neck fractures, and in particular the chronic cases, represented a challenging subset of cases presenting for total hip arthroplasty, resulting in suboptimal stem alignment in many cases. However, clinical outcomes were considered good to excellent in all dogs in the study, indicating that total hip arthroplasty is a viable treatment option for these types of fractures.

Evaluation of conventional and CT-based radiostereometric analysis for inducible displacement measurements after total hip arthroplasty.

Though radiostereometric analysis (RSA) is the gold standard for migration tracking, computed tomography-based RSA (CT-RSA) does not require marker beads and is available for clinical adoption. This study investigated CT-RSA in comparison to RSA for assessing hip implant stability with inducible displacement (ID) examinations. Patients (n = 48) from a previous study returned to be re-examined for femoral stem stability with CT-RSA and RSA imaging. Implant migration since patients last follow-up was calculated as a measure of stability. ID was assessed between alternated leg rotation scans for CT-RSA and between supine and weight-bearing scans for RSA. Measurements from ID and double examinations were compared between CT-RSA and RSA. All stems were well-fixed with migration <0.2 mm/year. ID measurements were lower with CT-RSA than RSA for distal translation (mean difference = 0.122 mm, p < 0.0001), total translation (mean difference = 0.158 mm, p < 0.0001), and total rotation (mean difference = 0.449°, p < 0.0001). The ID and double exam were significantly different for total translation and total rotation for CT-RSA, and significantly different for medial, distal, and total translation, and total rotation for RSA. Precision ranged from 0.049 to 0.130 mm in translation and 0.061° to 0.220° in rotation for CT-RSA, and from 0.108 to 0.269 mm in translation and 0.151° to 0.670° in rotation for RSA. ID measurements from both CT-RSA and RSA were minimal, consistent for a cohort with well-fixed stems. CT-RSA demonstrated superior precision in all axes compared to RSA. Clinical Significance: Future work should explore the use of CT-RSA in patients with suspected loosening as a potential diagnostic tool.

Uncemented and cemented hemiarthroplasty for femoral neck fracture with end-stage renal failure

Aim: The aim of this study is to evaluate the results of hemiarthroplasty performed with cemented and uncemented femoral stem in femoral neck fractures with ESRF. Material and Methods: Patients aged over 65 years with ESRF who admitted to our clinic for femoral neck fractures between January 2019 and June 2021 and underwent hemiarthroplasty, included in the study. Group 1 included patients with ESRF who underwent hemiarthroplasty with cemented stem due to femoral neck fracture. And group 2 included patients with ESRF who underwent hemiarthroplasty with uncemented stem due to femoral neck fracture. Functional scores of the patients and femoral stem loosening rates were evaluated with Harris Hip Score and radiographs. Result: 48 patients (21 male, 27 female) were included in the study. Twenty of the patients were treated with posterior approach and 28 were treated with anterolateral approach. The mean age of the patients was 78,6±11,32 years (range: 65-93 years).The mean follow up time was 28,9 months (24-36 months).There was no significant difference between loosening of cemented and uncemented stems (p= 0,087). The mean HHS of the patients was 69.5 for group 1 and 71.8 for group 2 (range 40-85). There was no significant difference between HHS of group 1 and 2 (p&gt;0.05). Conclusion: Patients with ESRF who underwent hemiarthroplasty due to femoral neck fracture have a higher complication risk. The loosening rates and functional scores of cemented and uncemented hemiarthroplasty are similar.