Proximal Femoral Geometry Research Articles

Acute Periprosthetic Hip Fractures With Short, Uncemented Femoral Stems

BackgroundUncemented femoral stems in hip arthroplasty have shown excellent long-term results, and several systematic studies indicate satisfactory performance of short stems. However, biomechanical and finite element analysis studies have suggested that shorter stems allow greater micromotion, producing greater strain at the implant-bone interface, which potentially increases the risk for periprosthetic fracture (PPF). We sought to assess this risk within our unit. MethodsOur institution’s arthroplasty database was searched for all primary total hip arthroplasties using short femoral stems performed between July 14, 2009 and August 29, 2022. The overall PPF rate and the PPF rate for individual femoral stems were established. Preoperative X-rays for each case were analyzed to characterize individual proximal femoral geometry. A data analysis was performed to identify risk factors for PPF. ResultsFor the time period assessed, 3,192 short femoral stems were implanted. This included 1,561 of stem A and 1,631 of stem B. Women constituted 55.37% of the cohort. The average patient age was 66 years (range, 22 to 95). The PPF rate was 0.6%, with 19 PPFs identified at a follow-up of 3 months. There was a significantly higher fracture rate in stem A (0.96%) compared to stem B (0.25%) (P ≤ .01). Proximal femoral geometry, age, and sex were not determined to be risk factors for PPF in our cohort. Individual surgeons and surgical approaches appeared to confer no increased risk. There was no significant difference in average stem length, but multivariate analysis identified stem type and stem length as an independent risk factor for PPF. ConclusionsOur study identified individual stem and stem length as independent risk factors for PPF within our cohort. PPF is a multifactorial issue, and consensus on emerging risk factors such as implant design will hopefully inform decisions that can provide further risk reduction for individual patients.

Stem anteversion is not affected by proximal femur geometry in robotic-assisted total hip arthroplasty

BackgroundIn the present study, the surgeon aimed to align the stem at 5° to 25° in anteversion. The robotic technology was used to measure stem anteversion with respect to proximal femur anteversion at different levels down the femur.MethodsA total of 102 consecutive patients underwent robotic-arm-assisted total hip arthroplasty (RTHA). 3D CT-based preoperative planning was performed to determine femoral neck version (FNV), posterior cortex anteversion (PCA), anterior cortex anteversion (ACA), and femoral metaphyseal axis anteversion (MAA) at 3 different levels: D (10 mm above lesser trochanter), E (the midpoint of the planned neck resection line) and F (head-neck junction). The robotic system was used to define and measure stem anteversion during surgery.ResultsMean FNV was 6.6° (SD: 8.8°) and the mean MAA was consistently significantly higher than FNV, growing progressively from proximal to distal. Mean SV was 16.4° (SD: 4.7°). There was no statistically significant difference (P = 0.16) between SV and MAA at the most distal measured level. In 96.1% cases, the stem was positioned inside the 5°–25° anteversion range.ConclusionsFemoral anteversion progressively increased from neck to proximal metaphysis. Aligning the stem close to femoral anteversion 10 mm above the lesser trochanter often led to the desired component anteversion.

Risk factors for templating mismatch of uncemented stems in bipolar hemiarthroplasty for femoral neck fracture

Preoperative templating needs to be precise to optimize hip arthroplasty outcomes. Unexpected implant mismatches can occur despite meticulous planning. We investigated the risk factors for oversized and undersized stem mismatch during uncemented hemiarthroplasty using a double-tapered wedge rectangular stem for femoral neck fracture. Out of 154 consecutive patients who underwent hemiarthroplasty for femoral neck fracture, 104 patients were divided into three groups: (1) oversized (n = 17; 16.3%), (2) matched (n = 80; 76.9%), and (3) undersized stem group (n = 7; 6.7%). A smaller femoral head offset (odds ratio [OR] = 0.89, 95% confidence interval [95% CI] = 0.81–0.98, P = 0.017), smaller isthmus diameter (OR = 0.57, 95% CI = 0.35–0.92, P = 0.021), and smaller canal flare index (OR = 0.20, 95% CI = 0.04–0.98, P = 0.047) were significantly associated with oversized stem insertion, while older age (OR = 1.18, 95% CI = 1.01–1.39, P = 0.037) was associated with undersized stem insertion in logistic regression. In conclusion, when performing hemiarthroplasty for a femoral neck fracture with a double-tapered wedge rectangular stem, surgeons must pay close attention to proximal femoral geometry and patient age during preoperative planning to avoid stem mismatch.

Value of Proximal Femur Geometry in Predicting Occult Hip Fracture.

Background and Objectives: Patients with occult hip fractures are a difficult subgroup to treat. MRI is the gold standard for diagnosing occult proximal femur fractures but is costly and may not be readily available in an emergency setting. The purpose of this study was to determine whether changes in the proximal femur geometry can predict the likelihood of an occult hip fracture in patients presenting with hip pain following a ground-level fall. Material and Methods: Patients admitted to the hospital with a clinical suspicion of a hip fracture but initial negative radiographs over a seven-year period were included. All patients were additionally investigated with an MRI scan, and retrospectively, six radiologic parameters were obtained on plain radiographs: The cortical thickness index (CTI), the canal to calcar ratio (CCR), the canal flare index (CFI), the morphological cortical index (MCI), the canal bone ratio (CBR) and the canal bone aria ratio (CBAR). Subsequently the result of the plain radiographic indices of the patients with a negative MRI (Group A, no occult fracture) were compared to those with a positive MRI (Group B, occult fracture). Results: A total of 78 patients (59 female, 19 male) could be included in the study. The mean age was 82 years. The univariate analyses revealed a poor predictive ability of all radiological parameters with AUC values ranging from 0.515 (CBR) to 0.626 (CTI), whereas a multivariate prognostic model demonstrated improved prognosis (AUC = 0.761) for the CTI (p = 0.024), CBAR (p = 0.074) and CRR (p = 0.081) as the most promising predictive radiological parameters. Conclusions: Single radiologic indices obtained from conventional X-rays of the proximal femur have a weak predictive value in detecting occult fractures of the hip and cannot be used as clinical decision-making factors.

Does the Proximal Femur Geometry Predict Early Functional Outcome after Plate Fixation of Geriatric Pertrochanteric Fractures?

The proximal femur geometry determines the hip force distribution. The femoral neck axis length (FNAL), the hip axis length (HAL), the femoral head diameter, and the femoral neck-shaft angle (FNSA) could influence the risk and outcome of pertrochanteric fractures. Restoring these parameters to their prefracture values could predict early hip function. To determine if the postoperative proximal femur geometry of geriatric patients with plating for pertrochanteric fractures predicts the early functional outcome. The study was a prospective study carried out at the National Orthopaedic Hospital Enugu for 18 months. Geriatric patients who had Proximal Femoral Locking fixation for pertrochanteric fractures were recruited. Radiological parameters of the proximal femur in the unaffected and fixed hips were measured and compared. The functional outcomes of the patients were measured at 3 months postoperative period using the Harris hip score (HHS). Multiple linear regression was conducted on the parameters to determine the HHS. Thirty patients participated in the study, with a significant difference (P < 0.001) in the mean FNSA between unaffected (M = 128.69, standard deviation (SD) =2.93) and operated hips (M = 121.81, SD = 8.86). The FNSA was the only significant predictor of hip function, with a 1-degree increase improving the HHS by 1.30. There is a significant difference in the FNSA between the unaffected and the operated hips. The FNSA significantly predicts the early hip function and should be reconstructed to within normal range during surgery.

A hierarchical clustering approach for examining the relationship between pelvis-proximal femur geometry and bone stress injury in runners

Bone stress injury (BSI) risk in runners is multifactorial and not well understood. Unsupervised machine learning approaches can potentially elucidate risk factors for BSI by identifying groups of similar runners within a population which differ in BSI incidence. Here, a hierarchical clustering approach is used to identify groups of collegiate cross country runners based on 2-dimensional frontal plane pelvis and proximal femur geometry, which was extracted from dual-energy X-ray absorptiometry scans and dimensionally reduced by principal component analysis. Seven distinct groups were identified using the cluster tree, with the initial split being highly related to female-male differences. Visual inspection revealed clear differences between groups in pelvis and proximal femur geometry, and groups were found to differ in lower body BSI incidence during the subsequent academic year (Rand index = 0.53; adjusted Rand index = 0.07). Linear models showed between-cluster differences in visually identified geometric measures. Geometric measures were aggregated into a pelvis shape factor based on trends with BSI incidence, and the resulting shape factor was significantly different between clusters (p < 0.001). Lower shape factor values, corresponding with lower pelvis height and ischial span, and greater iliac span and trochanteric span, appeared to be related to increased BSI incidence. This trend was dominated by the effect observed across clusters of male runners, indicating that geometric effects may be more relevant to BSI risk in males, or that other factors masked the relationship in females. More broadly, this work outlines a methodological approach for distilling complex geometric differences into simple metrics that relate to injury risk.

Sex estimation using proximal femoral parameters of adult population in the Volta region of Ghana

BackgroundThe estimation of sex is a fundamental component in the establishment of a biological profile and a critical step for the identification of skeletal remains in forensic contexts. The proximal femoral geometry is frequently evaluated at crime scene for the estimation of sex, but the use of radiograph anthropometry for the estimation of sex is rare, even though radiographs would be easier to handle than bone specimen. AimThe aim of this study was to estimate sex using proximal femoral parameters of adult population in the Volta region of Ghana. MethodThis study made use of 214 normal anteroposterior (AP) radiographs of the pelvis that showed the hip joints and the proximal femora. The age and sex were recorded. Four proximal femoral parameters were measured on the radiographs using the ‘DICOM radiology reader software. The hip axis length was measured and mean difference of the parameters between the genders and the laterality categories were assessed. ResultsThree out of the four parameters measured; femoral head diameter, neck diameter and hip axis length demonstrated statistically significantly difference (p = 0.0001) between the males and females in both right and left side measurement. The right hip axis length (RHAL) and left head diameter (LHD) contributed significantly to sex estimation. ConclusionThe right hip axis length demonstrates a high accuracy of 81.3% in sex determination among the population. This is the first study to present this finding in this population and might provide another way (if not easier way) to estimate the sex of a given skeletal specimen may give valuable insight into a better-customised implant and prosthesis design.

The effect of pre-fracture proximal femur geometry on hip fracture type in elderly patients.

This study aimed to analyze the relationship between fracture type by determining data on the geometry of the proximal femur in the pre-fracture period in patients over 65 years of age who had hip fractures as a result of low-energy trauma. A total of 127 patients who were admitted to the hospital for reasons other than hip pathology within 1 year before the occurrence of hip fracture and who had an anterior-posterior pelvic X-ray were included in the study. Measurements were made to evaluate the proximal femur geometry, neck shaft angle, central edge angle, femoral head diameter, femoral neck diameter, femoral neck length, femoral offset length, femoral neck axial length, hip axis length, and femoral shaft diameter. As a result of these measurements, analyses were performed to determine the relationship between the control group and fracture types. The mean Neck shaft angle scores were significantly higher in both fracture types than in the control group (P = .034, P = .002). The mean Femoral offset length values of both fracture types were lower than those of the control group (P = .002, P = .011, respectively). Multiple logistic regression analysis revealed that the risk of collum femoris fracture increased as the Femoral head diameter value increased. (OD = 0.21, P = .002). The geometric parameters of the proximal femur play an important role in the formation of hip fracture types. Therefore, differences in proximal femur geometry in hip fracture types should be considered, and patient-focused choices should be made regarding the surgical procedures and implants to be used during fracture fixation.

Early Total Hip Arthroplasty is a Cost-Effective Treatment for Severe Radiographic Slipped Capital Femoral Epiphysis Over an Individual's Lifetime

BackgroundSlipped capital femoral epiphysis (SCFE) causes degenerative changes warranting total hip arthroplasty (THA) in approximately 50% of patients by age 60 years. For severe SCFE, a reorienting intertrochanteric osteotomy (ITO) following in situ pinning (ISP) can decrease impingement with hip flexion, but by altering proximal femoral geometry, complicates subsequent conversion THA. We hypothesized that increasing implant survivorship would affect the most cost-effective treatment strategy (ISP followed by ITO [ISP + ITO] with later THA versus ISP alone [ISPa] with earlier THA) over a patient’s lifetime. MethodsA state-transition Markov model was constructed to analyze the cost-effectiveness of either ISPa or ISP + ITO over a 60-year time horizon for children who have severe, stable SCFE. Transition probabilities associated with implant and native hip survivorship, state utilities, and costs were derived from the literature. Sensitivity analyses assessed the model robustness. Incremental cost-effectiveness ratios (ICERs) were compared to a societal willingness to pay (WTP) of $100,000 per quality-adjusted life year (QALY). ResultsOver a 60-year horizon, ISPa was costlier ($291,836) than ISP + ITO ($75,227) but achieved overall better outcomes (51.4 QALYs ISPa versus 48.7 QALYs ISP + ITO), rendering ISPa cost-effective with an ICER of $80,980/QALY. Implant survivorship and time horizon were sensitive variables. ConclusionBased upon current implant performance, ISPa with subsequent earlier THA is cost-effective when considering an individual’s life expectancy and thereby deserves consideration in patients who have severe SCFE. Without clear level 1 clinical data, our economic model considers a difficult problem, while providing families and clinicians with a framework for understanding treatment options. Level of EvidenceEconomic and decision analysis, Level III.

Gluteus Maximus Tendon Reference: A Novel Method to Restore Leg Length in Total Hip Arthroplasty With Femoral Bone Loss

Accurate restoration of leg length and proximal femoral geometry is essential for achieving satisfactory outcomes in both primary and revision total hip arthroplasty. Although common landmarks such as the greater trochanter and the lesser trochanter (LT) may be used to measure limb length intraoperatively in primary cases, these landmarks may be absent or disrupted in fractures and revision procedures. We propose the distance between the gluteus maximus tendon gluteal sling (GS) and the center of the femoral head (FHC) as a novel anatomic landmark beyond the zone of injury, which can be used to restore limb length in the setting of proximal femoral bone loss or fracture. One hundred healthy hips were retrospectively reviewed using MRI to determine the distance between the proximal edge of the GS and the FHC. Additional measurements were collected including the distance between the GS and the greater trochanter and LT, as well as the FHC to the LT and greater trochanter.Results: The distance between the GS and the femoral head was consistent and measured 8.0 cm (±1.88 cm, SD = 0.66). A moderate positive correlation (r = 0.37, P < 0.001) was observed between patient height and GS to FHC distance. The distance between the GS and the center of the femoral head consistently measures 8 cm and can be used to set implant height to restore proximal femoral geometry and leg length in total hip arthroplasty with proximal femoral bone loss.

Proximal femur geometry: a major predictor of proximal femur fracture subtypes.

Proximal femur geometry (PFG) represents an important risk factor for the occurrence of hip fractures. There are currently few studies regarding the correlation between PFG and the occurrence of a specific fracture subtype, and those that exist have small cohorts and present with different methodologies and contradictory results. Therefore, there is no consensus in the literature regarding this topic. The present study aimed to establish the contribution of the PFG in the occurrence of different subtypes of proximal femur fractures (PFF): intertrochanteric, neck and subtrochanteric. Analysis of 1022 plain anteroposterior pelvic radiographs of patients consecutively admitted to the emergency room of a Level 1 Trauma Centre between 2013 and 2019 after low energy trauma who presented with PFF and underwent surgical treatment. Patients were analysed considering age, gender and subtype of PFF (intertrochanteric, neck or subtrochanteric). Radiological parameters including cervicodiaphyseal angle (CDA), horizontal offset (HO), femoral neck width (FNW), femoral neck length (FNL), great trochanter-pubic symphysis distance (GTPSD), acetabular teardrop distance (ATD) and width of the intertrochanteric region (WIR) were measured and compared between the different subtypes of fractures (7154 measurements). Statistical analysis was conducted recurring to absolute measurements and measurements ratios. The correlation was assessed using t-test. There were statistically significant differences in proximal femur geometry between the different subtypes of fractures. Patients presenting with femoral neck fractures had greater CDA (132.5 ± 6.9 vs. 130.0 ± 7.3; p < 0.001) and lower HO (45.8 ± 7.4 vs. 49.0 ± 8.0; p < 0.001), HO/ATD (0.34 ± 0.068 vs. 0.37 ± 0.072; p < 0.001) and HO/GTPSD (0.26 ± 0.049 vs. 0.28 ± 0.039; p < 0.001) than patients with intertrochanteric/subtrochanteric fractures. PFG represents an important contributor to the occurrence of different fracture subtypes. Femoral neck fractures are associated with greater CDA and lower HO, HO/ATD and HO/GTPSD when compared to intertrochanteric or subtrochanteric fractures.

Conversion total hip arthroplasty after previous intertrochanteric hip fractures: a review of the epidemiology, technical issues, and outcomes

Conversion total hip arthroplasty (THA) after previous intertrochanteric (IT) hip fracture is a unique operation that is different from the routine primary total hip arthroplasty (THA) done for osteoarthritis or femoral head necrosis. Conversion THAs are similar to revision THAs with regard to complexity, technical challenges, implant costs, and perioperative complications. A literature review was performed with specific focus on the surgical techniques, patient outcomes, and financial burdens of conversion THAs after IT fracture treatment with either a sliding compression hip screw with side plate (SSP), or a cephalomedullary nail (CMN). The reported data demonstrated similar technical challenges regardless of the method of the index treatment of the IT fracture. The surgeon must plan and be prepared for more difficult and extensile exposure, available instruments for the hardware removal, altered proximal femoral geometry, and available implant inventory for the reconstruction. The outcomes are consistent with higher rates of instability and infection in the conversion THAs compared with primary THAs. There is no significant difference in the clinical outcomes of conversion THAs following either SSP or CMN. Overall, conversion THAs pose greater technical challenges. The clinical outcomes of conversion THAs remain inferior to the primary THAs. The complications and patient functional outcomes are similar to those following revision THAs.

Morphometric study of proximal femur geometry in northern Odisha population

The human femoral head and neck-shaft angle measurements are important in proper femur implants and total hip replacement (THR). It can offer a guide to clinicians for the determination of risk factors for fractures (35). Proper standard sizes of diameter of the femoral head and neck shaft angle remains have always challenging for orthopaedic surgeons and anthropologist. The present study was conducted on 202 adult human femora available in Anatomy, Orthopaedic &amp; FMT departments of V.S.S Medical College, Burla, Odisha In the present study, various measurements of the femur like circumference of head, vertical, and transverse diameter of head showed the differences in measurements of Western-Odisha femora with western counterpart. These measurements are important in surgical procedures like total hip replacement. Thus, we strongly believe that such differences need to be considered when a total hip prosthesis is designed. There is a need for the population specific prosthesis design. But a possible drawback to our method of study is the measurements were taken on dry bones and these dimensions may change during drying process.

Study of proximal femoral geometry for standardizing femoral component in total hip replacement

Background and aims - Total Hip Replacement (THR) is the most common, permanent and effective surgical procedure available for the treatment of Osteoarthritis of the hip joint. In case of THR, it is mandatory that the design and dimensions of the femoral component, match (best-fit) the anatomy of the femur more so in cement-less variety. Significant variations are noted in the proximal femoral geometry of different races and ethnic groups Studies show that genetic and environmental factors including lifestyle determine the geometry of the proximal femur. The study is aimed to provide guidelines for future design of the femoral stem for Indian population. Materials &amp; Methods - The present study was conducted on 202 adult human femora available in Anatomy, Orthopaedic &amp; FMT departments of V.S.S Medical College, Burla, Odisha. The head vertical diameter (HVD), head transverse diameter (HTD), and circumference of femoral head (HC) were measured at the upper end of femur. The results were analyzed using statistical package SPSS 17.0 version. Results &amp; Conclusion- - The average HVD was 41.24 ± 3.41 mm. whereas the average HTD was nearly similar with HVD averaging 41.21± 3.44mm.

Hip Geometry and Proximal Femoral Fractures among Elderly Filipino Women: A Single Centre Cross-Sectional Study.

Introduction:Few controlled studies explore proximal femoral geometry and association with femoral neck (FN) or intertrochanteric (IT) fractures, especially among the elderly Filipino population. Previous reports, however, still reveal multiple inconsistencies. The objective of the study is to establish a possible association between radiographic hip geometry and proximal femoral fractures based on measurements taken from elderly Filipino women.Materials and methods:This is a cross-sectional study of 182 Filipino women ≥ 60 years old at a single institution last 2019-2020. Patients were divided into groups with femoral neck fractures (n=84), intertrochanteric fractures (n=64), and those without diagnosed hip fractures (n=34). Standard pelvic radiographs with control of hip internal rotation was done and the following radiographic parameters were compared: hip axis length (HAL), femoral neck length (FNL), neck shaft angle (NSA), horizontal offset (HO), femoral head diameter (FHD), and femoral neck diameter (FND).Results:Data suggests that an increased FND increased the risk for acquiring both femoral neck (OR = 1.31, 95% CI 1.06 - 1.62; p=.011) and intertrochanteric fractures (OR: 1.22, 95% CI 1.07-2.16; p=0.018). For intertrochanteric fractures alone, a wider NSA (OR 1.27, 95% CI 1.02 - 1.58, p=0.033) and larger HO (OR 1.29, 95% CI 1.02 - 1.64, p=0.036) also increased the risk for this fracture type while a longer HAL was protective (OR 0.85, 95% CI 0.73 - 0.98, p=0.30). Other radiographic parameters and ratios revealed no association.Conclusion:Results show that there are certain hip geometric parameters that play a role in the risk and incidence of developing femoral neck or intertrochanteric fractures. These measurements may aid in identification of patients at risk. This study may act as a guide for future implant design and increase accuracy of hip reconstruction among elderly Filipino women.

High-Intensity Exercise and Geometric Indices of Hip Bone Strength in Postmenopausal Women on or off Bone Medication: The MEDEX-OP Randomised Controlled Trial

To compare the effects of high-intensity resistance and impact training (HiRIT) to low-intensity, Pilates-based exercise (LiPBE) on proximal femur geometry and explore the influence of antiresorptive medication on those effects. Postmenopausal women with low bone mass, on or off antiresorptive bone medications were randomly allocated, stratified on medication intake, to eight months of twice-weekly, supervised HiRIT (Onero™) or LiPBE (Buff Bones®). 3D hip software was used to analyse proximal femur DXA scans. Outcomes included femoral neck (FN) and total hip (TH), volumetric (e.g. vBMC, vBMD) and geometric (e.g. cortical thickness, cross-sectional area [CSA], section modulus [Z]) indices of bone strength. Data were analysed using analysis of variance. Scans of 102 women were examined: LiPBE, 43; HiRIT, 37; LiPBE-med, 11; HiRIT-med, 11. HiRIT improved TH trabecular vBMC and vBMD (3.1 ± 1.1% versus − 1.2 ± 1.2%, p = 0.008; and 1.5 ± 1.0% versus − 1.6 ± 1.2%, p = 0.042, respectively) and FN and TH total vBMC (2.0 ± 0.8% versus − 0.2 ± 0.7%, p = 0.032; and 0.7 ± 0.4% versus − 0.8 ± 0.6%, p = 0.032, respectively), compared to losses in LiPBE. HiRIT also increased Z while LiPBE did not (p = 0.035). The combination of HiRIT and medication achieved greater improvements in FN total and trabecular vBMD, total BMC, CSA and Z than HiRIT alone. HiRIT improved geometric parameters of proximal femur strength, while LiPBE exercise was largely ineffective. Medication may enhance some HiRIT effects. Findings suggest reduced hip fracture risk in response to HiRIT.Trial registration number ACTRN12617001511325.

There is an association between Varus proximal femoral geometry and Atypical Femoral Fractures in postmenopausal women under chronic Bisphosphonate treatment?

There is an association between Varus proximal femoral geometry and Atypical Femoral Fractures in postmenopausal women under chronic Bisphosphonate treatment?

Reliability of assessing proximal femur geometry with Rutz classification schema in patients with cerebral palsy.

Our investigation aimed to assess the reliability of the femoral head shape classification system devised by Rutz et al . and observe its application in patients with cerebral palsy (CP) at different skeletal maturity levels. Four independent observers assessed anteroposterior radiographs of the hips of 60 patients with hip dysplasia associated with non-ambulatory CP (Gross Motor Function Classification System levels IV and V) and recorded the femoral head shape radiological grading system as described by Rutz et al . Radiographs were obtained from 20 patients in each of three age groups: under 8 years, between 8 and 12 years and above 12 years old, respectively. Inter-observer reliability was assessed by comparing the measurements of four different observers. To determine the intra-observer reliability, radiographs were reassessed after a 4-week interval. Accuracy was checked by comparing these measurements with the assessment of expert consensus. Validity was checked indirectly by observing the relationship between the Rutz grade and the migration percentage. The Rutz classification system's evaluation of femoral head shape showed moderate to substantial intra- and inter-observer reliability (mean κ = 0.64 for intraobserver and mean κ = 0.5 for interobserver). Specialist assessors had slightly higher intra-observer reliability than trainee assessors. The grade of femoral head shape was significantly associated with increasing migration percentage. Rutz's classification was shown to be reliable. Once the clinical utility of this classification can be established, it has the potential for broad application for prognostication and surgical decision-making and as an essential radiographic variable in studies involving the outcomes of hip displacement in CP. Level of evidence: III.

Asian Ethnicity and Femoral Geometry in Atypical Femur Fractures: Independent or Interdependent Risk Factors?

ABSTRACTThe earliest reports of atypical femur fractures (AFF) emerged from Asia. In the West, epidemiologic studies report a greater incidence of AFFs among subjects of Asian background. Asian ethnicity is an established risk factor for AFF, but clear mechanisms to explain this risk and implications for the general development of AFF are open questions. Ethno‐specific differences in bisphosphonate action and femoral geometry have been proposed as hypotheses. In a retrospective cohort of 163 female patients presenting with AFFs or typical femur fractures (TFF), relative contributions of Asian ethnicity, proximal femoral geometry, and bisphosphonate use in AFF status were examined. There was a fourfold higher proportion of Asian subjects in the AFF compared with TFF groups (31.6%, 30/95 versus 7.4%, 5/68). Asian subjects had smaller femurs in femoral head, neck, and axial dimensions. A multiple logistic regression model for AFF status was fitted adding Asian ethnicity to three previously reported independent predictors of AFF including femoral geometry, which together comprise the Sydney AFF Score (age ≤80 years, femoral neck width <37 mm than non‐Asian, lateral cortical width at lesser trochanter ≥5 mm). Asian ethnicity was a robust independent predictor of AFF, imparting sevenfold increase in the odds of AFF after adjusting for all three variables (95% confidence interval [CI] 2.2–23.2, p = 0.001) or for overall AFF score (95% CI 2.2–22.3 p = 0.001). Overall Asian subjects had higher rates of bisphosphonate use than non‐Asian subjects (67.6% versus 47.2%, p = 0.034). Among AFF bisphosphonate users, Asian subjects had lower AFF scores than non‐Asians (Sydney AFF Score ≤1, 45.5% Asian subjects versus 22.2% non‐Asian subjects, p = 0.05). Asian ethnicity is a strong independent risk factor for AFF, unaccounted for by ethno‐specific differences in proximal femoral geometry. Bisphosphonate use may be associated with a greater predisposition for AFF in Asian subjects compared with non‐Asian subjects. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Evaluation of the effect of proximal femur geometry on results of geriatric intertrochanteric fracture surgery.

This study aimed to explore the relationship between the complications and clinical outcomes after intertrochanteric femoral fracture surgery, and the Singh index (SI), canal-calcar ratio (CCR), cortical thickness index (CTI), and canal flare index (CFI) - the radiological indices defining proximal femoral morphology in the literature - among patients over 60 years of age. The data of 350 patients who were operated between 2015 and 2019 were evaluated retrospectively. The study included patients who underwent dual lag screw proximal femoral nailing and had good intraoperative reduction quality according to Fogagnolo's criteria. The relationships among radiological indices measured on radiographs acquired after trauma, and post-operative complications, Barthel activity index, and Harris hip score (HHS) were assessed statistically. Among 121 patients who met the study criteria, there were 63 (52.07%) female and 58 (47.93%) male patients. The mean length of follow-up was 37.09 (36-60) months. The patients had a mean age of 79.78 (60-97) years. At least one mechanical complication developed in 32 (26.4%) patients in the study group. No significant relationship could be established between radiological indices and post-operative complications (p>0.05). The relationship between SI and HHS was statistically significant (p<0.05). CCR, CTI, and CFI did not have a statistically significant relationship with and HHS (p>0.05). No statistically significant relationship could be established between radiological indices and post-operative complications. It should be considered that SI may be a parameter that affects clinical outcomes.