Hip Morphology Research Articles

Interobserver agreement and clinical disparity between the Graf method and femoral head coverage measurement in developmental dysplasia of the hip screening: A prospective observational study of 198 newborns.

Ultrasonography is the ideal tool for assessing hip morphology in infants younger than 6-month-old. This study assessed the interobserver agreement and clinical disparities of the 2 most widely used ultrasound (US) methods, the Graf method, and femoral head coverage (FHC) measurement.A prospective observational study (STROBE compliant) of 2024 newborns was conducted between January 2017 and December 2018. Hip US was conducted on all newborns with abnormal Barlow and Ortolani maneuvers as well as on 50 randomly selected normal newborns. The physical examination and US were performed by a senior pediatric orthopedic surgeon with musculoskeletal sonography certification. Three observers with different levels of experience interpreted the images by using the Graf method and FHC. We analyzed the intraclass correlation coefficient, Cohen kappa, and the disparity between the clinical findings of the 2 methods.A total of 198 newborns (9.8%) presented with clinical instability, including 193 subluxatable hips in 168 patients (84.8%) and 45 dislocatable/dislocated hips in 30 patients (15.2%). The mean age at US examination was 11.69 days (range: 0–18 days). The intraclass correlation coefficient was .71 (95% CI: 0.55–0.83) for FHC, 0.63 (95% CI: 0.38–0.78) for the alpha angle, and 0.47 (95% CI: 0.16–0.69) for beta angle. The Cohen kappa coefficients of Graf type were 0.19 (95% CI: 0.03–0.35), 0.39 (95% CI: 0.20–0.58), and 0.17 (95% CI: 0.02–0.32) between observers 1 and 2, observers 1 and 3, and observers 2 and 3, respectively. Based on the Graf method, 14% of the stable hips had abnormal USs; by contrast, 19.2% of the subluxatable hips and 17.8% of the dislocatable/dislocated hips had normal Graf morphologies. In USs interpreted using FHC, 16% of stable hips demonstrated abnormal coverage, whereas 13.5% of subluxatable hips and 4.4% of dislocatable/dislocated hips had normal FHC.Incidence of clinically detectable hip instability was 9.8% among newborns in our series. Both alpha angle and FHC ratio revealed substantial interobserver agreement while beta angle achieved moderate agreement. FHC ratio possesses higher sensitivity and similar specificity compared with the Graf method when screening unstable hips.Level II, development of diagnostic criteria on basis of consecutive patients

Machine learning identifies factors related to early joint space narrowing in dysplastic and non-dysplastic hips.

To utilise machine learning, unsupervised clustering and multivariate modelling in order to predict severe early joint space narrowing (JSN) from anatomical hip parameters while identifying factors related to joint space width (JSW) in dysplastic and non-dysplastic hips. A total of 507 hip CT examinations of patients 20-55 years old were retrospectively examined, and JSW, center-edge (CE) angle, alpha angle, anterior acetabular sector angle (AASA), and neck-shaft angle (NSA) were recorded. Dysplasia and severe JSN were defined with CE angle < 25o and JSW< 2 mm, respectively. A random forest classifier was developed to predict severe JSN based on anatomical and demographical data. Multivariate linear regression and two-step unsupervised clustering were performed to identify factors linked to JSW. In dysplastic hips, lateral or anterior undercoverage alone was not correlated to JSN. AASA (p < 0.005) and CE angle (p < 0.032) were the only factors significantly correlated with JSN in dysplastic hips. In non-dysplastic hips, JSW was inversely correlated to CE angle, AASA, and age and positively correlated to NSA (p < 0.001). A random forest classifier predicted severe JSN (AUC 69.9%, 95%CI 47.9-91.8%). TwoStep cluster modelling identified two distinct patient clusters one with low and one with normal JSW and different anatomical characteristics. Machine learning predicted severe JSN and identified population characteristics related to normal and abnormal joint space width. Dysplasia in one plane was found to be insufficient to cause JSN, highlighting the need for hip anatomy assessment on multiple planes. • Neither anterior nor lateral acetabular dysplasia was sufficient to independently reduce joint space width in a multivariate linear regression model of dysplastic hips. • A random forest classifier was developed based on measurements and demographic parameters from 507 hip joints, achieving an area under the curve of 69.9% in the external validation set, in predicting severe joint space narrowing based on anatomical hip parameters and age. • Unsupervised TwoStep cluster analysis revealed two distinct population groups, one with low and one with normal joint space width, characterised by differences in hip morphology.

3-D acetabular morphology of the neuromuscular hip: implications for preoperative planning.

The importance of precisely understanding the pathoanatomy of acetabular dysplasia prior to surgical treatment has long been recognized. Acetabuloplasties for neuromuscular hip dysplasia have typically aimed to improve the acetabulum by increasing posterior-superior coverage, as previous three-dimensional (3-D) computed tomography (CT) studies have shown that acetabular dysplasia in neuromuscular hips is primarily in the direction of posterior-superior subluxation or dislocation. The purpose of this study was to identify differences in 3-D morphology between normal hips and dysplastic neuromuscular hips, specifically to identify areas of acetabular deficiency to guide preoperative decision-making. Patients treated for neuromuscular hip dysplasia at a single institution between 2009 and 2017 with a preoperative high-resolution pelvic CT scan (28 hips) were evaluated with custom software to measure acetabular morphology. Acetabuli were divided into equal octants; coverage angles were measured for each octant of interest. Variables were compared with age- and sex-matched normal controls (56 hips). We found a wide range of hip pathology in our study cohort. Five hips had no sectors with abnormal coverage. One hip (4%) was overcovered anteriorly. The remaining pathology was undercoverage located anteriorly [n = 7 (25%)], superiorly [n = 6 (21%)], posteriorly [n = 4 (14%)] or globally [n = 5 (18%)]. Our findings indicate that individual patients with neuromuscular acetabular dysplasia have unique deformities that do not uniformly conform to a specific area of acetabular deficiency. It is imperative to define the specific 3-D acetabular deficiency location and magnitude for accurate preoperative planning. Level of evidence: Level III.

Hip Morphology in Early-stage LCPD: Is There an Argument for Anatomic-specific Containment?

Early containment surgery has become increasingly popular in Legg-Calvé-Perthes Disease (LCPD), especially for older children. These procedures treat the proximal femur, the acetabulum, or both, and most surgeons endorse the same surgical option regardless of an individual patient's anatomy. This "one-surgery-fits-all" approach fails to consider potential variations in baseline anatomy that may make one option more sensible than another. We sought to describe hip morphology in a large series of children with newly diagnosed LCPD, hypothesizing that variation in anatomy may support the concept of anatomic-specific containment. A retrospective review of a prospectively collected multicenter database was conducted for patients aged 6 to 11 at diagnosis. To assess anatomy before significant morphologic changes secondary to the disease itself, only patients in Waldenström stages IA/IB were included. Standard hip radiographic measurements including acetabular index, lateral center-edge angle, proximal femoral neck-shaft angle (NSA), articulotrochanteric quartiles, and extrusion index (EI) were made on printed anteroposterior pelvis radiographs. Age-specific percentiles were calculated for these measures using published norms. Significant outliers (≤10th/≥90th percentile) were reported where applicable. A total of 168 patients with mean age at diagnosis of 8.0±1.3 years met inclusion criteria (81.5% male). Mean acetabular index for the entire cohort was 16.8±4.1 degrees; 58 hips (34.5%) were significantly dysplastic compared with normative data. Mean lateral center-edge angle was 15.9±5.2 degrees at diagnosis; 110 (65.5%) were ≤10th percentile indicating dysplasia (by this metric). Mean NSA overall was 136.5±7.0 degrees. Fifty-one (30.4%) and 20 (11.9%) hips were significantly varus (≤10th percentile) or valgus (≥90th percentile), respectively. Thirty-five hips (20.8%) were the third articulo-trochanteric quartiles or higher suggesting a higher-riding trochanter at baseline. Mean EI was 15.5%±9.0%, while 63 patients (37.5%) had an EI ≥20%. The present study finds significant variation in baseline anatomy in children with early-stage LCPD, including a high prevalence of coexisting acetabular dysplasia as well as high/low NSAs. These variations suggest that the "one-surgery-fits-all" approach may lack specificity for a particular patient; a potentially wiser option may be an anatomic-specific containment operation (eg, acetabular-sided osteotomy for coexisting dysplasia, varus femoral osteotomy for valgus NSA). Level IV.

Ischiofemoral impingement: the evolutionary cost of pelvic obstetric adaptation.

The risk for ischiofemoral impingement has been mainly related to a reduced ischiofemoral distance and morphological variance of the femur. From an evolutionary perspective, however, there are strong arguments that the condition may also be related to sexual dimorphism of the pelvis. We, therefore, investigated the impact of gender-specific differences in anatomy of the ischiofemoral space on the ischiofemoral clearance, during static and dynamic conditions. A random sampling Monte-Carlo experiment was performed to investigate ischiofemoral clearance during stance and gait in a large (n = 40 000) virtual study population, while using gender-specific kinematics. Subsequently, a validated gender-specific geometric morphometric analysis of the hip was performed and correlations between overall hip morphology (statistical shape analysis) and standard discrete measures (conventional metric approach) with the ischiofemoral distance were evaluated. The available ischiofemoral space is indeed highly sexually dimorphic and related primarily to differences in the pelvic anatomy. The mean ischiofemoral distance was 22.2 ± 4.3 mm in the females and 29.1 ± 4.1 mm in the males and this difference was statistically significant (P < 0.001). Additionally, the ischiofemoral distance was observed to be a dynamic measure, and smallest during femoral extension, and this in turn explains the clinical sign of pain in extension during long stride walking. In conclusion, the presence of a reduced ischiofemroal distance and related risk to develop a clinical syndrome of ischiofemoral impingement is strongly dominated by evolutionary effects in sexual dimorphism of the pelvis. This should be considered when female patients present with posterior thigh/buttock pain, particularly if worsened by extension. Controlled laboratory study.

Is Radiographic Osteoporotic Hip Morphology A Predictor For High Mortality Following Intertrochanteric Femur Fractures?: Osteoporotic Hip Morphology & Mortality

Introduction: Factors related to mortality after intertrochanteric femur fractures (ITFF) have been investigated intensively in the literature except for radiographic osteoporotic hip morphology. The aim of this study is to investigate the relationship between mortality and radiographic osteoporotic hip morphology of patients with ITFF.Patients and methods: Patients who underwent surgery between the dates of January 2012 and June 2018 due to ITFF were retrospectively reviewed. Osteoporotic status of the proximal femur was determined based on Singh Index grading and Dorr classification systems on preoperative anteroposterior pelvis radiographs of contralateral hips. The mortality rates of the patients were measured at 1st, 3rd, 6th, and 12th months. For controlling the confounders, multiple regression analysis was performed.Results: A total of 321 consecutive ITFFs were included in the study. The mean age of the patients was 81.5 ± 6.6 years. All patients were treated with osteosynthesis utilizing a cephalomedullary nail. The overall mortality rates at 1st, 3rd, 6th, and 12th months were 7.2%, 13.4%, 16.2%, 22.7%, respectively. There was 2.196 (1.140 - 4.229) folds increase in the mortality rate of patients with the Dorr type C femurs at 6th month (p=0.019). However, Singh index grade was not significantly associated with mortality.Conclusion: Patients with Dorr type C femur seem to have 2.1 times increased mortality at 6th months following ITFFs. A simple anteroposterior pelvis radiograph obtained during the initial evaluation of the patients may be used to estimate the mortality rate after ITFF.

Hip joint space width in an asymptomatic population: Computed tomography analysis according to femoroacetabular impingement morphologies

BackgroundAlthough the association between femoroacetabular impingement (FAI) syndrome and hip osteoarthritis (OA) is well established, not all hips exhibiting cam or pincer morphologies (i.e. imaging findings of FAI syndrome) are symptomatic or arthritic. It is difficult to detect which subgroup will wear out, or how does the arthritic process start radiographically. Therefore, we measured in a retrospective study based on computed tomography (CT) analysis, the joint space width (JSW) according to a standard protocol and we investigated its variation according to the presence of a cam and/or pincer morphology. We hypothesized that the radiological presence of a cam and/or pincer hip morphologies, even in asymptomatic subjects, would affect JSW. MethodsTwo hundred pelvic CT scans performed for non-orthopedic etiologies in asymptomatic patients were analyzed using a 3D software. After excluding patients with hip OA or previous hip surgery, 194 pelvic CT scans (388 hips) were retained. We measured for each hip the presence of FAI syndrome imaging findings (cam and pincer morphologies) using the classical parameters of coxometry. In addition, we performed a measurement of articular joint space width according to a standard protocol. We then calculated the mean thickness of 3 defined regions along the femoroacetabular joint: anterior-superior, posterior-inferior, and posterior-superior. Lastly, we compared the JSW across 4 groups: hips with (1) no cam or pincer, (2) pincer, (3) cam, and (4) cam and pincer morphologies using a multivariate analysis. Additionally, a topographic heatmap of JSW was plotted allowing quantitative representation of JSW along the joint. ResultsIncreased JSW with peak difference of 0.9 mm (25.7%) was found in hips with cam and pincer morphologies when compared to normal ones (p = 0.002) and to hips with pincer or cam morphologies only. ConclusionPositive variations in JSW were associated to the presence of cam and pincer morphologies. This significant increase in JSW could be one of the earliest measurable changes preceding later classical alterations.

The influence of adult hip shape genetic variants on adolescent hip shape: Findings from a population-based DXA study.

ObjectiveHip shape is a well-recognized risk factor for hip osteoarthritis (OA) and hip fracture. We aimed to investigate whether the genetic variants known to be associated with adult hip shape were also associated with adolescent hip shape.MethodsHip DXA scans, obtained in offspring from the Avon Longitudinal Study of Parents and Children (ALSPAC) at two time points (mean ages 13.8 and 17.8 years), were used to quantify hip morphology using a 53-point Statistical Shape Model (SSM). Principal component analysis was used to generate hip shape modes (HSMs). Genetic variants which had previously shown genome-wide significant association with specific HSMs in adults were tested for association with the same HSMs in adolescents (at each timepoint separately) using SNPTEST v2.ResultsComplete genotypic and phenotypic data were available for 3550 and 3175 individuals at 14 and 18 years, respectively. The strongest evidence for association with adolescent hip shape was for a variant located near SOX9 (rs2158915) with consistent effects across both time points for HSM1 (age 14: beta −0.05, p = 9.9 × 10−8; age 18: −0.05, p = 3.3 × 10−6) and HSM5 (age 14: beta −0.07, p = 1.6 × 10−4; age 18: −0.1, p = 2.7 × 10−6). There was also strong evidence of association between rs10743612 (near PTHLH) and HSM1 (age 14: 0.05, p = 1.1 × 10−5; age 18: 0.04, p = 0.003) and between rs6537291 (near HHIP) and HSM2 (age 14: −0.06, p = 0.001; age 18: −0.07, p = 0.001) across both time points. The genes with the strongest associations with hip shape in adolescents, (SOX9, PTHLH and HHIP) are known to be involved in endochondral bone formation. HSM1 indicates narrower aspect ratio of the upper femur, whereas both HSM2 and HSM5 reflect variation in the femoral head size and femoral neck width, features previously found to be related to the risk of OA in later life. The SOX9 locus has previously been found to associate with increased risk of hip fracture.ConclusionIn conclusion, variants implicated in endochondral bone formation appear to consistently influence hip shape between adolescence and adulthood, including those aspects related to risk of hip OA and/or fracture in later life.

Value of susceptibility-weighted imaging for the assessment of angle measurements reflecting hip morphology

Radiographs are the clinical first line imaging modality for evaluating hip morphology and pathology. MRI offers additional information and is the method of choice to evaluate soft tissue, bone marrow and preradiographic signs of osteoarthritis. Radiographs are used to measure the most morphometric parameters. The aim of this study was to compare susceptibility weighted MRI (SWMR) with radiographs to evaluate hip morphology. 40 Patients were examined with standard MR-sequences, coronal SWMR and radiographs in anteroposterior pelvic view. Coronal maximum intensity projection (MIP) images of both hips were automatically reconstructed on SWMR and T1weighted images. Sharp´s angle, Tönnis angle, lateral center–edge angle of Wiberg and caput-collum-diaphyseal angle were measured on coronal SWMR MIP-images, T1weighted MIP-images and radiographs. Measurements were compared by linear regression analysis and Bland-Altmann Plots, using radiographs as reference standard. Additionally, a ratio between the signal intensity of muscles and bone on SWMR and T1weighted MIP-images was calculated and compared between these two sequences. SWMR enables the reliable assessment of Sharp´s angle (SWMR: R2 = 0.80; T1weighted: R2 = 0.37), Tönnis angle (SWMR: R2 = 0.86; T1weighted: not measurable), lateral center–edge angle of Wiberg (SWMR: R2 = 0.88; T1weighted: R2 = 0.40) and caput-collum-diaphyseal angle (SWMR: R2 = 0.38; T1weighted: R2 = 0.18) compared to radiographs with a higher accuracy than conventional MR imaging. The ratio between the intensity of muscles and bone was significant higher on SWMR (2.00 and 2.02) than on T1weighted MIP-images (1.6 and 1.42; p < 0.001).

Application of statistical shape modeling to the human hip joint: a scoping review protocol.

This review aims to identify all examples of the application of statistical shape models to the human hip joint, with a focus on methodology, validation, and applications. Abnormal hip joint morphology (eg, deformity secondary to Legg-Calvé-Perthes disease) is an important precursor to osteoarthritis. Clinical radiographs are often used to characterize deformity and provide indication for surgical correction, but it is unclear whether radiographs can adequately describe three-dimensional deformity. Statistical shape modeling, a method of describing a population of shapes using a small number of variables, has been identified as a potential tool that will allow clinicians and researchers to validate current and novel radiographic measurements of hip deformity. In identifying all previous examples of statistical shape modeling applied to the hip joint, this review will determine its prevalence, strengths, and weaknesses, and identify gaps in the literature. Peer-reviewed and gray literature focusing on the development and/or application of statistical shape models to the human hip joint will be included. Several relevant databases, including Ovid MEDLINE, Embase, and IEEE, will be searched for literature published from 1992, and for a title and abstract that can be searched in English. After removal of duplicates, two reviewers will independently screen papers by title and abstract, then screen the full text of selected or uncertain papers. The same reviewers will then independently chart data from the final selection. At each stage, disagreements will be resolved through discussion or third-party arbitration.

Hip disease in Mucopolysaccharidoses and Mucolipidoses: A review of mechanisms, interventions and future perspectives.

The hips are frequently involved in inheritable diseases which affect the bones. The clinical and radiological presentation of these diseases may be very similar to common hip disorders as developmental dysplasia of the hip, osteoarthritis and avascular necrosis, so the diagnosis may be easily overlooked and treatment may be suboptimal. Mucopolysaccharidosis (MPS) and Mucolipidosis (ML II and III) are lysosomal storage disorders with multisystemic involvement. Characteristic skeletal abnormalities, known as dysostosis multiplex, are common in MPS and ML and originate from intra-lysosomal storage of glycosaminoglycans in cells of the cartilage, bones and ligaments. The hip joint is severely affected in MPS and ML. Hip pathology results in limitations in mobility and pain from young age, and negatively affects quality of life. In order to better understand the underlying process that causes hip disease in MPS and ML, this review first describes the normal physiological (embryonic) hip joint development, including the interplay between the acetabulum and the femoral head. In the second part the factors contributing to altered hip morphology and function in MPS and ML are discussed, such as abnormal development of the pelvic- and femoral bones (which results in altered biomechanical forces) and inflammation. In the last part of this review therapeutic options and future perspectives are addressed.

Should we employ preoperative templating in hip hemiarthroplasty after femoral neck fracture? A nested case-control study.

Dislocation following hip hemiarthroplasty is a serious complication. It remains unclear if acetabular morphology is associated with a higher risk of dislocation. The aim of our study was to investigate whether there are differences in hip morphology radiological parameters between patients who have suffered a dislocation episode, and those who have not suffered a dislocation. Between January 2015 and December 2018, a nested case-control study was performed. From 707 patients who underwent hip hemiarthroplasty because of femoral neck fracture, 50 patients (50 hips) suffered an episode of dislocation. They were randomly matched with 94 patients (100 hips) without dislocation (ratio 1:2). Clinical data regarding demographics, medical comorbidities and surgical and radiological parameters were studied. Statistically significantly smaller lateral centre-edge angle (LCEA) and femoral offset (FO) and greater Tönnis angle were found in the dislocation group. No differences in acetabular angle were seen. Neurological impairment prevalence was statistically significantly higher in patients who suffered a dislocation (60% vs. 44%, p = 0.011). The current study suggests that a smaller LCEA and FO, a greater TA, and neurological impairment could be related to a higher risk of hip hemiarthroplasty dislocation after femoral neck fracture in the elderly. We consider that preoperative templating could be helpful in identifying abnormal parameters and carefully planning surgery could lead to changes in treatment strategy, such as choosing a dual-mobility total hip arthroplasty.

A comparative radiographic morphometric analysis to assess the normal radiological morphology of the adult hip in indian population

ObjectiveOur objective is to analyze the normal radiological morphologic parameters of the adult hip joint of the Indian population and compare it with standard measurements and with other populations to assess the variations. MethodsA prospective analysis of the normal pelvis X-rays of 800 persons (1600 hips) was done. We have calculated the acetabular inclination, acetabular index, lateral center edge angle (LCEA) and neck-shaft angle (NSA), sphericity of the femoral head, congruity of the joint, version of the acetabulum, depth of acetabulum, and lateralization of the femoral head in normal X-rays of the pelvis in adult persons. We used RadiAnt DICOM viewer version 4.6.5.18450 (64bit) for measurement. Statistical analysis and mean values were calculated using SPSS software. ResultsThere were 978 X-rays of the male hip and 622 female. The acetabular inclination varied from 1 to 9. The mean acetabular index was 26.5. The LCEA was between 20 and 50. The mean neck-shaft angle was 133. There were 35, hips with an aspherical head. 94.2% X-rays the hip joint was congruent. There was 2.9% of the retroversion of acetabulum, 3.3% lateralization. ConclusionMost of the parameters were comparable to standard values the acetabular index was lower. LCEA and NSA were higher. The acetabular angle was lower. There were femoral head asphericity, joint incongruity, and lateralization of the femoral head in a small proportion of our general population.

3D hindlimb joint mobility of the stem-archosaur Euparkeria capensis with implications for postural evolution within Archosauria

Triassic archosaurs and stem-archosaurs show a remarkable disparity in their ankle and pelvis morphologies. However, the implications of these different morphologies for specific functions are still poorly understood. Here, we present the first quantitative analysis into the locomotor abilities of a stem-archosaur applying 3D modelling techniques. μCT scans of multiple specimens of Euparkeria capensis enabled the reconstruction and three-dimensional articulation of the hindlimb. The joint mobility of the hindlimb was quantified in 3D to address previous qualitative hypotheses regarding the stance of Euparkeria. Our range of motion analysis implies the potential for an erect posture, consistent with the hip morphology, allowing the femur to be fully adducted to position the feet beneath the body. A fully sprawling pose appears unlikely but a wide range of hip abduction remained feasible—the hip appears quite mobile. The oblique mesotarsal ankle joint in Euparkeria implies, however, a more abducted hindlimb. This is consistent with a mosaic of ancestral and derived osteological characters in the hindlimb, and might suggest a moderately adducted posture for Euparkeria. Our results support a single origin of a pillar-erect hip morphology, ancestral to Eucrocopoda that preceded later development of a hinge-like ankle joint and a more erect hindlimb posture.

Age-related differences in morphology and kinematics of the native hip.

Our objectives were to clarify morphology of the hip as well as infinitesimal femoral head movement in specific positions in young and elderly volunteers without joint degeneration. Both hips of 20 young and 20 elderly healthy volunteers were examined. Magnetic resonance imaging was performed at four different positions for each hip: neutral, 45° flexion, 15° extension, and the Patrick position. Femoral and pelvic bone images were separately extracted when in the neutral position and superimposed over the images of each different position by using voxel-based registration. The distance between the acetabular center and the femoral head center (FHC) at the neutral position was defined as 3D-migration. The distance between FHCs at neutral position and that at each different position was defined as 3D-translation. The x-, y-, and z-axes pointed in the anterior, cranial, and lateral directions, respectively. 3D-migration-y in the elderly was more caudal than that in the young (P < .001). 3D-translation of 45° flexion in the elderly was larger than that in the young with statistical significance (P = .001), while 3D-translation of the Patrick position in the elderly was smaller than that in the young (P = .012). Age was significantly correlated with 3D-translation in 45° flexion (r = .431; P < .001) and that in Patrick (r = -.296; P = .008). These results can be used as a basis for the natural course with aging of morphometry and kinematics of the hip, as well as for potential disease progression in osteoarthritis of the hip.

Influence of changes in hip bone morphology and anterior knee pain

Introduction: The patellofemoral pain syndrome (PFPS) is one of the most common disorders of the knee, and there is still unclear etiology. Objective: The aim of this study was to correlate patellofemoral pain syndrome with the bone morphology of hip. Method: For this, this study evaluated 31 studied volunteers with aged between 18 and 30 years, which analyzed the distance of anterior superior iliac spines (ASIS), asymmetry of the pelvis, lower limb length (LL), distance from the ASIS bilaterally of the patella, lateral tilt and iliac inclination, this by computerized biophotogrammetry. Results: After collecting the data and consequent tabulation, it was found that were no changes in the data collected except in the lateral tilt, so the volunteers who had anterior knee pain also had lateral pelvic tilt. Conclusion: That said, we can infer that there is little relationship between the morphological changes of the hip with the PFPS, whereas found only one was in lateral pelvic tilt voluntary group who complained of pain above the knee.

Standard Radiographic Assessment of Femoral Cam Morphology is Influenced by Neck-Shaft Angle and Femoral Version

Objectives:Cam-type femoroacetabular impingement (FAI) is a three-dimensional (3D) deformity that is still difficult to assess using traditional two-dimensional (2D) radiographic views. While measurements of alpha angle and head-neck offset are used to estimate the likelihood of actual impingement, these 2D measurements do not account for z-axis variations in femoral version (FV) and neck-shaft angle (NSA). The purpose of this qualitative proof-of-concept study was to evaluate the potential variation in alpha angle and neck-shaft offset measurements with incremental changes in NSA and FV by simulating traditional radiographic views with software-generated Digitally-Reconstructed Radiographs (DRRs). We hypothesize that incremental changes in hip morphology will produce qualitative changes in alpha angle and neck-shaft offset.Methods:3D-CT reconstruction images were obtained from one subject with symptomatic cam-type FAI. The 3D reconstruction was cleaned to include only the femoral head, neck and subtrochanteric region along with the ipsilateral hemipelvis. Using 3D medical image processing software (Mimics; Materialise, Inc.; Belgium), the pre-processed 3D model was manipulated in a standardized manner to simulate 5-degree incremental variations in FV and NSA (-15 degrees to +15 degrees for FV; -15 degrees to +10 degrees for NSA). Negative FV reflected external rotation of the femoral head-neck unit, whereas negative NSA reflected abduction of the femoral head-neck unit. Each modified 3D model was then used to generate DRRs corresponding to traditional 2D radiographic views used for assessment of cam-FAI (Anteroposterior [AP], False Profile [FP]), Cross Table Lateral [CTL], Frog Leg Lateral [FLL], 45- and 90-degree Dunn [45D and 90D, respectively]. Alpha angle and head-neck offset were measured on each radiographic view corresponding to each incremental change in FV and NSA. All measurements utilized the perfect circle technique and were made by two independent observers for assessment of inter-observer reliability. Two-way random effects ANOVA was used for statistical assessment of inter-observer reliability and reported as intra-class correlation coefficients (κ). Comparisons between groups were performed using two-tailed paired t-tests assuming unequal variance. P-values less than 0.05 were considered statistically significant.Results:Inter-observer reliability (κ) for head-neck offset and alpha angles were 0.46 (fair) and 0.88 (excellent), respectively. Variations in head-neck offset and alpha angle with incremental variations in FV and NSA are summarized in Figure 1. There were statistically significant changes in mean alpha angles when the NSA was adjusted from Neutral to -5 degrees (p=0.01) and from -5 degrees to -10 degrees (p<0.001). There were no statistically significant differences in alpha angles or head-neck offsets between each incremental change in FV (p<0.05). Alpha angle measurements were significantly more variable than head-neck offset measurements for all variations in FV (p<0.001) and NSA (p=0.02) (Figure 2).Conclusion:Two-dimensional evaluation of three-dimensional Cam morphology (alpha angle and head-neck offset) was found to be significantly affected by alterations in femoral version and head-neck offset. Head-neck offset measurements were significantly less variable than alpha angle measurements across all FVs and NSAs within each radiographic view. Future work should be done to develop standardized procedures for routine 3D radiographic assessment of cam-type FAI.Figure 1.Figure 2.

Acetabular Dysplasia: Three-Dimensional Deformity Predictors of the Diagnosis of Symptomatic Instability Treated with Periacetabular Osteotomy

Objectives:Borderline acetabular dysplasia is classically defined as a lateral center edge angle (LCEA) of 20-25 degrees. The optimal treatment strategy in this patient group remains controversial, with some patients having primarily hip instability-based symptoms, while others have primarily impingement-based symptoms (non-instability). The purpose of the current study was to define the 3D characteristics on low-dose CT that differentiate patients with instability symptoms from those without instability in the setting of borderline acetabular dysplasia.Methods:Seventy consecutive hips with borderline acetabular dysplasia undergoing surgical treatment were included in the current study. All patients underwent low-dose pelvic CT with femoral version assessment for preoperative planning. CT measurements included alpha angle and radial acetabular coverage (RAC) at standardized clockface positions (9:00-posterior to 3:00-anterior), central and cranial acetabular version. RAC was assessed in three sectors (anterior, superior, and posterior) and defined (relative to published normative data) as normal (-1 SD, +1 SD), undercoverage (<-1 SD), or overcoverage (>+1 SD). Statistical analysis was performed to compare the CT characteristics of the symptomatic instability and non-instability groups.Results:Of the 70 hips, 62.9% had the diagnosis of symptomatic instability, while 37.1% had no instability symptoms. Hips with instability (compared to non-instability) had significantly lower alpha angle (maximal difference at 1:00 - 47.0° vs. 59.4°), increased femoral version (22.3° vs. 15.3°), and decreased radial acetabular coverage (maximal difference at 1:00 – 59.9% vs. 62.2%) (all p<0.001). Multivariate analysis identified femoral version (OR 1.1, p=0.02), alpha angle at 1:00 (OR 0.91, p=0.02), and RAC at 1:00 (OR 0.46, p=0.003) as independent predictors of the presence of instability. The model combining these three factors had excellent predictive probability with a c-statistic 0.92.Conclusion:We found significant differences in the 3D hip morphology of the symptomatic instability and non-instability subgroups within the borderline dysplasia cohort. In the setting of borderline dysplasia, three-dimensional deformity characterization with low-dose CT allowed for differentiation of patients diagnosed with underlying instability vs. non-instability. Femoral version, alpha angle at 1:00, and radial acetabular coverage at 1:00 were identified as independent predictors of diagnosis in borderline acetabular dysplasia.

Patient-related risk factors associated with less favourable outcomes following hip arthroscopy.

This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy. Literature reporting on preoperative patient-related risk factors and outcomes following hip arthroscopy were systematically identified from a computer-assisted literature search of Pubmed (Medline), Embase, and Cochrane Library using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and a scoping review. Assessment of these texts yielded 101 final articles involving 90,315 hips for qualitative analysis. The most frequently reported risk factor related to a less favourable outcome after hip arthroscopy was older age and preoperative osteoarthritis of the hip. This was followed by female sex and patients who have low preoperative clinical scores, severe hip dysplasia, altered hip morphology (excess acetabular retroversion or excess femoral anteversion or retroversion), or a large cam deformity. Patients receiving workers' compensation or with rheumatoid arthritis were also more likely to have a less favourable outcome after hip arthroscopy. There is evidence that obesity, smoking, drinking alcohol, and a history of mental illness may be associated with marginally less favourable outcomes after hip arthroscopy. Athletes (except for ice hockey players) enjoy a more rapid recovery after hip arthroscopy than non-athletes. Finally, patients who have a favourable response to local anaesthetic are more likely to have a favourable outcome after hip arthroscopy. Certain patient-related risk factors are associated with less favourable outcomes following hip arthroscopy. Understanding these risk factors will allow the appropriate surgical indications for hip arthroscopy to be further refined and help patients to comprehend their individual risk profile. Cite this article: Bone Joint J 2020;102-B(7):822-831.

More than one way to be a giant: Convergence and disparity in the hip joints of saurischian dinosaurs

Saurischian dinosaurs evolved seven orders of magnitude in body mass, as well as a wide diversity of hip joint morphology and locomotor postures. The very largest saurischians possess incongruent bony hip joints, suggesting that large volumes of soft tissues mediated hip articulation. To understand the evolutionary trends and functional relationships between body size and hip anatomy of saurischians, we tested the relationships among discrete and continuous morphological characters using phylogenetically corrected regression. Giant theropods and sauropods convergently evolved highly cartilaginous hip joints by reducing supraacetabular ossifications, a condition unlike that in early dinosauromorphs. However, transitions in femoral and acetabular soft tissues indicate that large sauropods and theropods built their hip joints in fundamentally different ways. In sauropods, the femoral head possesses irregularly rugose subchondral surfaces for thick hyaline cartilage. Hip articulation was achieved primarily using the highly cartilaginous femoral head and the supraacetabular labrum on the acetabular ceiling. In contrast, theropods covered their femoral head and neck with thinner hyaline cartilage and maintained extensive articulation between the fibrocartilaginous femoral neck and the antitrochanter. These findings suggest that the hip joints of giant sauropods were built to sustain large compressive loads, whereas those of giant theropods experienced compression and shear forces.