Femoral Neck Anteversion Angle Research Articles

Segmental femoral fracture malunion: evidence and prognostic analysis of medical intervention in the third century BC

We examined the remains of an individual who was unearthed from the Tuchengzi site and was believed to be from the Warring States period in China. The remains exhibited segmental femoral fracture. We aimed to deduce the cause of fracture, medical interventions, healing process, and motion behavior after fracture healing using several techniques, including macroscopic observation, computed tomography (CT), and finite element analysis. Based on the morphology of the long bones, it appeared that the individual was male. The fractures resulted in an adduction angle of 5.47° and an anterior flexion angle of 21.34° in the proximal femur, while the femoral neck anteversion angle had been replaced by a retroversion angle of 10.74°. Additionally, the distal femur formed an abnormal anterior convex angle of 144.60°. CT revealed mature callus formation and visible trabecular bundles. The finite element analysis indicated that the maximum von Mises stress in the femur was 17.44 MPa during standing and 96.46 MPa during walking. We suggest that medical practitioners in the Warring States period possessed a good knowledge of thigh anatomy, enabling them to perform fracture reduction and fixation. Reasonable medical intervention facilitated fracture healing and load recovery. Satisfactory fracture healing ensured that the individual could engage in normal standing and walking activities after rehabilitation.

Macroscopic differences in adult human femora are linked to body mass index.

Bone functional adaptation is routinely invoked to interpret skeletal morphology despite ongoing debate regarding the limits of the bone response to mechanical stimuli. The wide variation in human body mass presents an opportunity to explore the relationship between mechanical load and skeletal response in weight-bearing elements. Here, we examine variation in femoral macroscopic morphology as a function of body mass index (BMI), which is used as a metric of load history. A sample of 80 femora (40 female; 40 male) from recent modern humans was selected from the Texas State University Donated Skeletal Collection. Femora were imaged using x-ray computed tomography (voxel size ~0.5 mm), and segmented to produce surface models. Landmark-based geometric morphometric analyses based on the Coherent Point Drift algorithm were conducted to quantify shape. Principal components analyses were used to summarize shape variation, and component scores were regressed on BMI. Within the male sample, increased BMI was associated with a mediolaterally expanded femoral shaft, as well as increased neck-shaft angle and decreased femoral neck anteversion angle. No statistically significant relationships between shape and BMI were found in the female sample. While mechanical stimulus has traditionally been applied to changes in long bong diaphyseal shape it appears that bone functional adaptation may also result in fundamental changes in the shape of skeletal elements.

[Progress in diagnosis and hip arthroscopic treatment of borderline developmental dysplasia of hip with Cam-type femoroacetabular impingement].

To summarize the biomechanical characteristics, diagnosis, and hip arthroscopic treatment of borderline developmental dysplasia of hip (BDDH) with Cam-type femoroacetabular impingement (Cam FAI). The literature on BDDH with Cam FAI at home and abroad in recent years was extensively reviewed and analyzed. In patients with BDDH and Cam FAI, the femoral neck anteversion angle and femoral neck shaft angle increase, the pelvis tilts, and the acetabulum rotates, resulting in instability of the hip joint. In order to maintain the stability of the hip joint, the direction of biomechanical action of the hip joint has changed, which further affects the anatomical structures such as the proximal femur and acetabular morphology. BDDH with Cam FAI can be diagnosed clinically by combining lateral center edge angle, anterior center edge angle, and acetabular index. BDDH with Cam FAI can be effectively treated through arthroscopic polishing of the edges of the acetabular proliferative bone, excision of Cam malformations, and minimally invasive repair of the glenoid lip and cartilage of the hip joint. Currently, there is no unified standard for the diagnosis and treatment of BDDH with Cam FAI. Minimally invasive treatment of the hip under arthroscopy can achieve good early- and medium-term effectiveness, and has certain advantages in repairing and maintaining the integrity of the glenoid lip and suturing/compression joint capsule. However, the long-term effectiveness needs to be further followed up to determine. The timing of surgery, intraoperative bone edge depth polishing, and joint capsule suturing/compression techniques also need to be further explored.

Side-to-side variability in the femoral neck anteversion angle: A study of the Japanese population with osteonecrosis of the femoral head

BackgroundSide-to-side variability in the femoral neck anteversion angle (FA) reportedly varies from 0.0° to 17.3°. To investigate the side-to-side variability in the FA and the relationship between the FA and the morphology of the acetabulum in the Japanese population, we performed a three-dimensional computed tomography (CT)-based study involving patients with osteonecrosis of the femoral head (ONFH). MethodsCT data were obtained from 170 nondysplastic hips of 85 patients with ONFH. The FA and acetabular coverage parameters, including the acetabular anteversion angle, acetabular inclination angle, and acetabular sector angle in the anterior, superior, and posterior directions, were measured using three-dimensional CT. The distribution of the side-to-side variability in the FA was evaluated separately for each of the five degrees. ResultsThe mean side-to-side variability in the FA was 6.7° ± 5.3° (range, 0.2°–26.2°). The distribution of the side-to-side variability in the FA was 0.0°–5.0° in 41 patients (48.2%), 5.1°–10.0° in 25 patients (29.4%), 10.1°–15.0° in 13 patients (15.3%), 15.1°–20.0° in 4 patients (4.7%), and >20.1° in 2 patients (2.4%). There was a weak negative correlation between the FA and anterior acetabular sector angle (r = −0.282, P < 0.001) and a very weak positive correlation between the FA and acetabular anteversion angle (r = 0.181, P < 0.018). ConclusionsThe mean side-to-side variability in the FA was 6.7° ± 5.3° (range, 0.2°–26.2°) in Japanese nondysplastic hips, and about 20% of the patients had a side-to-side variability of >10°.

Effects of hindlimb suspension on development of proximal and distal femur morphological abnormalities in growing rats.

Although morphological abnormalities of the femur are known predisposing factors for numerous musculoskeletal disorders, the etiology of these abnormalities is poorly understood. This study aimed to investigate whether femoral morphogenesis is affected by hindlimb suspension (HS) in growing rats. We used 41 four-week-old female rats in this study. In the HS groups, rats were suspended from their tails for 2, 4, and 8 weeks. Age-matched animals were used as controls. We examined morphological indices of the femur using three-dimensional reconstructed images from X-ray computed tomography. The femoral neck anteversion angle (AVA) was higher with growth in the experimental groups and did not differ in control groups. The AVAs in the HS groups were larger than controls at any time point. In the control groups, the trochlear angle (TA) was higher, rotating inward with growth, but did not differ in the HS groups. The TAs in the HS groups were smaller and rotated more outward compared with the control groups at any time point. The height ratios of the medial and lateral condyles (MC/LC), an asymmetry index, were larger in the HS groups compared to controls at any time point. There were strong relationships between proximal (AVA) and distal morphologies, such as the TA (Spearman's coefficient [rs ] = -0.80, p < 0.001) and MC/LC (rs  = 0.79, p < 0.001). Our data suggest that sufficient physical activity in early life may protect against morphological femur abnormalities associated with hip and knee joint diseases.

Determination of the Gender-Related Differences on Native Femoral Anatomy Using Three-Dimensional Computerized Tomography Models in Caucasian Population.

IntroductionThree-dimensional (3D) modelling, which has an increasing interest in the literature, could help surgeons to better understand the lesions by visualizing the real anatomical features compared to plain radiographs and two-dimensional (2D) tomography images. We aimed to evaluate the native femoral anatomical features of Turkish females and males using 3D computed tomography models.MethodsWe evaluated the right femoral anatomical features of 60 females and 60 males between 31 and 65 years of age creating 3D computerized tomography models. The gender-specific differences of femoral neck inclination and anteversion, femoral mechanical-anatomical axis, anatomical and mechanical lateral distal femoral, medial and lateral proximal femoral angles were measured on 3D femoral anatomical models.ResultsThe mean age of our study groups was 50.6 ± 8.5. We determined a statistically significant difference between gender groups in terms of mean femoral neck anteversion angles (p = 0.009). We observed the retroversion of the femoral neck in 12 adults (10%). The mean values of femoral neck inclination, femoral mechanical - anatomical angle, anatomical and mechanical lateral distal femoral angles, medial and lateral proximal femoral angles did not differ any statistical significance between gender groups.ConclusionAlthough the anatomical angle measurements except femoral neck anteversion, did not differ significantly between gender groups of our study, there were differences between mean anatomical angles when compared to other studies in the literature, which investigate the different races or Caucasian population. Through 3D anatomical data, more compatible implants, prosthesis or biomaterials can be produced by determining gender and race-specific anatomical differences.

Accuracy of CT for measuring femoral neck anteversion in children with developmental dislocation of the hip verified using 3D printing technology

BackgroundAccurate femoral neck anteversion angle (FNA) measurement is of great significance in the diagnosis and treatment of developmental dysplasia of the hip (DDH) in children. The FNA measurement still remains a controversy. We aimed to verify the accuracy of our CT method by 3D printing technology and to evaluate its clinical value.MethodsSixty-eight children with unilateral DDH were enrolled, and their FNA was measured using 2D-CT and 3D-CT, respectively, by three observers. This procedure was repeated 3 months later. The above measurement outcomes were then compared with the results in the 3D-printed femur (3D-PF) model. The FNA in the 3D-PF model was measured by three observers (two radiologists and one orthopedist; all were professors) collectively through electronic angle instrument.ResultsThe primary measurement of FNA at the affected hips by 2D-CT was 44.0 ± 6.1, 49.5 ± 8.9, and 52.8 ± 7.9°, respectively. On the 3D-CT, it was 47.6 ± 5.4, 49.3 ± 6.8, and 48.6 ± 6.2°. Three months later, the FNA on 2D-CT was 49.3 ± 10.5, 42.8 ± 7.4, and 45.1 ± 9.3°, and it was 48.0 ± 6.5, 48.9 ± 7.2, and 49.0 ± 5.7° on 3D-CT, respectively. The FNA in the 3D-PF model at the affected and unaffected hips was 48.5 ± 6.6 and 36.9 ± 13.1°. There were significant differences between 2D-CT and 3D-PF measurements, but no significant difference was found between 3D-CT and 3D-PF measurements. The results by 2D-CT showed significant differences among groups and between the groups. However, the results by 3D-CT had no significant differences among groups or between the groups.ConclusionThe results of our study showed that 3D-CT is a more precise, and reproducible method for FNA measurement in DDH. The FNA at the affected hips is 11.6° larger than the unaffected in DDH children aged 3–8 years.

Proximal femoral geometry analysis of igbos of South East Nigeria and its clinical application in total hip replacement and hip surgeries: A dry bone study.

Proximal femoral geometry(PFG) plays a role in the biomechanics of the hip. During total hip replacement detailed efforts are made to restore this biomechanics in other to ensure patients satisfaction and implant survival. There are variations in these parameters. Ethnicity is one of the most influential factors accounting for these variations. To determine the values of the parameters of the proximal femoral geometry among the ethnic Igbos of the South Eastern Nigeria, determine any correlation between these parameters, and compare these values with known populations as well as discuss the clinical application in total hip replacement and other hip surgeries. Materials and Method: Seven hundred and sixteen (716) femoral bones taken from the osteology unit of department of anatomy of University of Nigeria Enugu Campus (UNEC) were screened and proximal femoral parameters measured using Vernier calipers. Results: There were 356 right and 360 left femoral bones with the following values: Femoral Neck Anteversion Angle (FNAVA): M=19.04°, SD=2.075°, Proximal Femoral Length(PFL): M=73.24mm,SD=7.622, Femoral Head Vertical Diameter(FHVD):M= 44.64mm, SD=3.134, Femoral Head Transverse Diameter(FHTD),M=44.55mm, SD=3.379mm, Femoral Head Diameter(FHD),M=44.60mm, SD=3.119mm, Femoral Neck Anterior Length(FNAL), M=31.86mm, SD=5.383mm, Femoral Posterior Neck Length(FPNL):M=22.23mm, SD=3.520mm, Femoral Neck Diameter (FND), M=32.71mm,SD= 3.315mm, Proximal Femoral Width Head to Side (PFWHS), M=89mm.80,SD= 10.331mm, Proximal Femoral Width Side to Side (PFWSS), M=31.47mm, SD=2.812mm, Femoral Neck Shaft Angle(FNSA), M=132.15°, 7.305°. The parameters of the proximal femoral geometry of the ethnic Igbos of the South East of Nigeria, differed from other populations and exhibited laterality.

Initial Rotational Instability of the Tapered Wedge-Shaped Type Cementless Stem.

Background Because the tapered wedge-shaped type cementless stem has a small anteroposterior width and a low occupation rate in the medullary space, postoperative rotational instability and stem subsidence due to inadequate proximal fixation are concerns. The purpose of this study was to clarify the relationship between the rotational instability of the tapered wedge-shaped type cementless stem and femoral canal shape. Methods A total of 61 primary total hip arthroplasties with the tapered wedge-shaped type cementless stem Accolade® TMZF (11 males, 50 females; mean age 60 years) from January 2012 to June 2015 who underwent computed tomography before surgery and within 4 weeks and 1 year after surgery were evaluated. The preoperative femoral neck anteversion angle, preoperative femoral canal flair index, the degree of postoperative stem subsidence within 1 year after operation, and the degree of rotational change in the stem setting angle within 1 year after operation were investigated. Results The mean preoperative femoral neck anteversion angle was 32.2° ± 17.8° (0°–69°), and the mean preoperative canal flair index was 3.68 ± 0.58 (2.44–5.55). There were no stem subsidence cases within 1 year after operation. The mean degree of rotational change in the stem from immediately to 1 year after surgery was −0.4° ± 1.7° (−3°–3°). There was no significant correlation between the canal flair index and the rotational change in the stem. In addition, the mean difference between the preoperative femoral neck anteversion angle and the stem rotational angle immediately after surgery was only 1.3° ± 5.3° (−29°–15°). Conclusions In all cases, including stove-pipe cases, the degree of rotational change in the Accolade® TMZF stem from immediately to 1 year after surgery was within 3°. In other words, regardless of femoral canal shape, the tapered wedge-shaped type cementless stem has little initial rotational instability.

[Risk of micro-fracture in femoral head after removal of cannulated screws for femoral neck fracture].

To explore the changes of bone and risk of micro-fracture in femoral head after removal of cannulated screws following femoral neck fracture healing under the impact force of daily stress. A total of 42 specimens of normal hip joint were collected from 21 adult fresh cadaveric pelvic specimens. Wiberg central-edge (CE) angle, bone mineral density, diameter of femoral head, neck-shaft angle, and anteversion angle of femoral neck were measured. Then, the 3 cannulated screws were implanted according to the AO recommended method and removed to simulate the complete anatomical union of femoral neck fracture. The morphology of screw canal in the femoral head was observed by CT. Finally, the specimens were immobilized vertically within the impact device in an upside-down manner, and the femoral heads were impacted vertically. Every specimen was impacted at 200, 600, and 1 980 N for 20 times with the impacting device. After impact, every specimen was scanned by CT to observe the morphology changes of screw canal in the femoral head. Micro-fractures in the femoral head could be confirmed when there was change in the morphology of screw canal, and statistical software was used to analyze the risk factors associated with micro-fractures. After impact at 200 and 600 N, CT showed that the morphology of screw canal of all specimens did not change significantly compared with the original. After impact at 1 980 N, there were protrusion and narrowing in the screw canal of the 22 femoral head specimens (11 pelvic specimens), showing obvious changes compared with the original screw canal, indicating that there were micro-fractures in the femoral head. The incidence of micro-fracture was 52.38% (11/21). logistic regression results showed that there was correlation between micro-fracture and bone mineral density ( P= 0.039), but no correlation was found with CE angle, diameter of femoral head, neck-shaft angle, and anteversion angle ( P>0.05). The micro-fractures in the femoral head may occur when the femoral head is impacted by daily activities after removal of cannulated screws for femoral neck fractures, and such micro-fractures are associated with decreased bone density of the femoral head.

The lateral center-edge angle as radiographic selection criteria for periacetabular osteotomy for developmental dysplasia of the hip in patients aged above 13 years

BackgroundThis retrospective study sought to delineate the radiographic characteristics of DDH patients over 13 years of age and investigate whether the lateral center-edge angle (LCEA) could serve as radiographic selection criteria for periacetabular osteotomy.MethodsWe enrolled patients with Hartofilakidis type I DDH without dislocation who underwent periacetabular osteotomy between August 2009 and August 2012. LCEA, anterior central edge angle (ACEA), femoral neck-shaft angle (FNSA), Shenton line and Tönnis acetabular index (AI) were evaluated by anteroposterior and 65° false⁃profile pelvic X-ray radiographs in the standing position. Femoral neck anteversion angle (FNA), labral lesion, labral inversion and cartilage lesion were evaluated by direct magnetic resonance arthrography. DDH was categorized by LCEA into four grades (grade I: 10° ≤ LCEA< 20°, grade II: 0° ≤ LCEA< 10°, grade III: -10° ≤ LCEA< 0°, grade IV: LCEA<-10) and osteoarthritis (OA) severity was assessed using Tönnis OA classification. Pearson correlation analysis was done between LCEA and other variables.ResultsTotally patients (274 hips) with a mean age of 27.3 years (range 13–47 years) were included. The mean LCEA was 3.5° (range: − 30° to 20°). Based on LCEA grades, grade I DDH was present in 104 hips, grade II in 40 hips, grade III in 76 hips, and grade IV in 54 hips. Based on Tönnis OA classification, 54.5% hips (150/274) were grade 0, 33.1% hips (91/274) grade 1, 8.4% hips (23/274) grade 2 and 4% hips (11/274) grade 3. Pearson correlation analysis showed a negative correlation between LCEA grade and Tönnis OA grades (r = 0.3987; P < 0.001). Cochran-Armitage trend test further showed a positive correlation between LCEA grades and labral lesion (P < 0.001) and interrupted Shenton line (P < 0.001).ConclusionThe LCEA classification scheme offers a simple and practical approach to categorize the level of acetabulum coverage on the femoral head, hip deformity and characteristics of DDH. Our findings could provide clinically useful guidance for orthopedic surgeons in preparation for periacetabular osteotomy in DDH patients aged above 13 years.

A novel method for quantifying femoral neck anteversion: A case study in extinct and extant sloths.

Extinct sloths represent a wide range of morphological, locomotor, and body size variation. Researchers have examined femoral neck angle in two dimensions to hypothesize locomotor behaviors in this group; however, this measure does not account for femoral neck anteversion. Here, we present a new method for quantifying femoral neck anteversion angle, in addition to femoral neck angle, to capture the 3D position of the femoral head/neck. Femora of extant (n = 21; Bradypus and Choloepus) and extinct (n = 49; Acratocnus, Megalocnus, Neocnus, and Parocnus) sloths were surface scanned and their surface models used to calculate three angles of femoral neck anteversion and femoral neck angle. Femoral neck anteversion was calculated as the angle between the femoral neck axis and the geometric axis of the femoral condyles (GA), the 35% cross section axis, and a trochanter axis. Femoral neck angle was calculated as the angle between the femoral neck and shaft axes. Genera were compared using ANOVAs with post hoc multiple comparisons for each angle. Femoral neck angle and femoral neck anteversion relative to the cross section were also analyzed. Significant differences among genera exist for all angles, (p < .001) but not all angles separate all genera. Femoral neck and anteversion angles typically yield different results, demonstrating the utility of analyzing both angles. The GA and cross section angles are highly correlated in sloths, with the exception of comparisons among Megalocnus, Parocnus, and Neocnus, suggesting morphological variation in the distal femur. While this method was applied to sloths, it has broad applicability to mammalian groups.

Three-dimensional morphological analysis of the femoral neck torsion angle\u2014an anatomical study

BackgroundThe femoral neck torsion angle (FNTA) is an important but often neglected parameter in assessments of the anatomical morphology of the femoral neck, which is often confused with the femoral neck anteversion angle (FNAA) in the current literature. Currently, the measurement methods reported in the literature all adopt the naked eye or two-dimensional (2D) visualization method, and the measurement parameters and details are not clearly defined. The objection of this research was to provide a reliable 3D method for determining the femoral neck axis, to improve the measurement method of the FNTA, and to analyze the anatomical and clinical significance of the results.MethodsComputed tomography (CT) data of 200 patients who received a lower extremity CT angiography examination were selected, and the bilateral femurs were reconstructed with three dimensional CT (3D CT). First, the 3D axis of the femoral neck was built. Second, the long axis of the cross section the femoral neck isthmus (FNI) and femoral neck basilar part (FNB) were confirmed by the “inertia axes” method, and the plane consisting of the long axis of the cross-section and the center of the femoral head was defined as the long axial plane. Third, the coronal plane of the proximal femur was determined through the long axis of the proximal femur and the femoral coronal. Finally, the FNTAs (the angles between the long axial planes and the coronal plane of the proximal femur) of FNI and FNB were measured. The size of FNTA was compared between the sexes and sides and different locations, the correlation between the parameters and age, height, and weight were evaluated.ResultsThe difference in FNTA was statistically significant between the isthmus and the basilar part (isthmus 30.58 ± 8.90° vs. basilar part 23.79 ± 3.98°; p < 0.01). Significant difference in the FNTA was observed between the sexes (males 31.99 ± 9.25° vs. females 27.49 ± 7.19°; p < 0.01). The increase in FNTA from the basilar part to the isthmus was 6.79 ± 8.06°, and the male (7.87 ± 8.57°) was greater than the female (4.44 ± 6.23°, p < 0.01). However, no significant difference in the values was observed between sides. Height exerted the greatest effect on the FNTA according to the correlation analysis (r = 0.255, p< 0.001).ConclusionsThis study found a reliable 3D method for the determination of the femoral neck axis improved the measurement method of the FTNTA and made it more accurate and repeatable. The results provided a methodological basis and theoretical support for the research and development of internal fixation device for femoral neck fracture and the spatial configuration of implants in treatment. And the optimal opening point of the femoral medullary cavity was recommended to locate at the posterior position of the top of the femoral neck cross-section during hip replacement.

Gender and age differences in anatomical parameters of proximal femur in middle-aged and elderly patients with femoral intertrochanteric fracture

Objective To determine the gender and age differences in anatomical parameters of proximal femur in middle-aged and elderly patients with femoral intertrochanteric fracture so as to provide theoretical evidence for development of internal fixation devices. Methods The clinical and CT data of 375 patients with intertrochanteric fracture were analyzed retrospectively who had been treated at Department of Orthopedics, The First Medical Center, General Hospital of Chinese PLA from September 2009 to March 2017. The patients were divided into 4 age groups. The middle-aged group (from 45 to 59 years old) had 22 cases, 16 males and 6 females; the early elderly group (from 60 to 74 years old) had 87 cases, 37 males and 50 females; the elderly group (from 75 to 89 years old) had 238 cases, 76 males and 162 females; the late elderly group (≥90 years old) had 28 cases, 6 males and 22 females. The anteversion angle of femoral neck, femoral neck-shaft angle, femoral head diameter, femoral neck length, femoral neck offset and femoral neck width were measured on their images. The anatomical parameters of proximal femur were compared between genders in the same age group and between groups of the same gender. Results There were no significant differences between male and female patients with femoral intertrochanteric fracture in body mass index or AO classification, showing comparability(P>0.05). The anteversion angle of femoral neck (8.33°±5.00°) of the male middle-aged and elderly patients with intertrochanteric fracture was significantly smaller than that of the female ones (11.28°±6.15°), but their femoral head diameter, femoral neck length, femoral neck offset and femoral neck width (49.10 mm±2.48 mm, 99.70 mm±5.22 mm, 7.18 mm±2.20 mm and 39.10 mm±4.92 mm) were significantly larger than those of the female ones (43.46 mm±2.79 mm, 90.00 mm ± 4.75 mm, 6.29 mm±2.07 mm and 33.49 mm±4.87 mm) (all P 0.05). Conclusions Compared with the middle-aged and elderly male patients with femoral intertrochanteric fracture, the middle-aged and elderly female ones have a larger anteversion angle of femoral neck, smaller offset, width and length of femoral neck, and a smaller femoral head diameter. There are no significant age differences in anatomical parameters of the proximal femur in middle-aged and elderly patients with femoral intertrochanteric fracture. Key words: Hip fractures; Femur; Clinical anatomy; Gender; Imaging, three-dimensional

[Influence of femoral neck area on larger anteversion angle of lag screw guide pin initial placement in proximal femoral intramedullary nail fixation].

To invstigate the influence of femoral neck area on larger anteversion angle of lag screw guide pin initial placement in proximal femoral intertrochanteric fracture treated with intramedullary nail. From June 2014 to June 2016, 60 patients with femoral intertrochanteric fractures were treated with intramedullary nail, including 27 males and 33 females with an average age of 75 years old ranging from 49 to 88 years old. The lateral images of femoral neck were divided into areas during operation. The anteversion angle of lag screw guide pin of proximal femoral nail was observed at the time of initial insertion. The incidence of normal and larger was counted and the angle index of influencing factors was recorded. Among 60 patients, the screw guide pins of 23 cases were in the central region of the femoral neck and the anteversion angle was normal;screw guide pins of 37 cases were in the front area of the femoral neck, leading to larger anteversion angle. The single factor analysis showed that the independent variables influence factors of larger anteversion were internal collection of the affected limb, internal rotation of the affected limb, hip elevation and screw guide pin level(P<0.05). The multi-factor regression analysis showed that the anteversion angle larger was significantly related to the internal rotation of the affected limb and screw guide pin level, and the screw guide pin level was the most relevant(P=0.030). The internal rotation of the affected limb and screw guide pin level may affect the anteversion angle of femoral neck when lag screw guide pin initial insertion, cause it to be too large and the screw guide pin level is the main influencing factor.

MR study of longitudinal variations in proximal femur 3D morphological shape and associations with cartilage health in hip osteoarthritis

The goal of this study was to use quantitative MRI analysis to longitudinally observe the relationship between 3D proximal femur shape and hip joint degenerative changes. Forty-six subjects underwent unilateral hip MR imaging at three time points (baseline, 18 and 36 months). 3D shape analysis, hip cartilage T1ρ /T2 relaxation time quantification, and SHOMRI MRI grading were performed at each time point. Subjects were grouped based on KL, SHOMRI, and HOOS pain scores. Associations between these score groupings, time, and longitudinal variation in shape, were analyzed using a generalized estimating equation. One-way ANCOVA was conducted to evaluate change in shape as a predictor of the worsening of degenerative changes at 36 months. Our results demonstrated that subjects displayed an increase in the volume of the femoral head and neck (Mode 3) over time. This shape mode was significantly more prevalent in patients that reported pain. Longitudinal changes in this shape mode also served as borderline predictors of elevated T1ρ values (p = 0.055) and of cartilage lesions (p = 0.068). Subjects showed a change in the Femoral Neck Anteversion angle (FNA) over time (Mode 6). This shape mode showed a significant interaction with the presence of cartilage lesions. The results of this study suggest that specific variations in bone shape quantified through 3D-MRI based Statistical Shape modeling show an observable relationship with hip joint compositional and morphological changes. The shapes observed lead to early degenerative changes, which may lead into OA, thus confirming the important role of bone shape changes in the pathogenesis of OA. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Femoral neck anteversion angle: Standardization of measuring method and its clinical implication

To evaluate the prevalence of pterygium and its determinants in the underserved, rural population of Iran.In this cross-sectional study of 3851 selected individuals, 86.5% participated in the study, and the prevalence of pterygium was evaluated in 3312 participants. A number of villages were selected from the north and south of Iran using multistage cluster sampling. Pterygium was diagnosed by the ophthalmologist using slit-lamp examination.The mean age of the study participants was 37.3 ± 21.4 years (2–93 years), and 56.3% (n = 1865) of them were women. The prevalence of pterygium was 13.11% [95%confidence interval (CI):11.75–14.47]. The prevalence of pterygium was 14.99 (95%CI:12.79–17.19) in men and 12.07 (95%CI:10.3–13.84) in women. Pterygium was not seen in children below the age of 5 years. The prevalence of pterygium increased linearly with age; the lowest and highest prevalence of pterygium was observed in the age group 5–20 years (0.19%) and 61–70 years (28.57%). Evaluation of the relationship between pterygium with age, sex, educational level, and place of living using a multiple model showed that age, living in the south of Iran, and low educational level were correlated with pterygium.The prevalence of pterygium was significantly higher in Iranian villages when compared with the results of previous studies. This finding may represent the effect of a rural lifestyle and its risk factors.

3D printing technology used in severe hip deformity.

This study was designed to assess the use of a 3D printing technique in total hip arthroplasty (THA) for severe hip deformities, where new and improved approaches are needed. THAs were performed from January 2015 to December 2016. Bioprosthesis artificial hip joints were used in both conventional and 3D printing hip arthroplasties. A total of 74 patients (57 cases undergoing conventional hip replacements and 17 undergoing 3D printing hip replacements) were followed-up for an average of 24 months. The average age of the patients was 62.7 years. Clinical data between the patients treated with different approaches were compared. Results showed that the time to postoperative weight bearing and the Harris scores of the patients in the 3D printing group were better than those for patients in the conventional hip replacement group. Unfortunately, the postoperative infection and loosening rates were higher in the 3D printing group. However, there were no significant differences in femoral neck anteversion, neck shaft, acetabular or sharp angles between ipsilateral and contralateral sides in the 3D printing group (P>0.05). The femoral neck anteversion angle was significantly different between the two sides in the conventional hip replacement group (P<0.05). Based on these results, we suggest that the 3D printing approach provides a better short-term curative effect that is more consistent with the physiological structure and anatomical characteristics of the patient, and we anticipate that its use will help improve the lives of many patients.

Proximal femur geometry in the adult Kenyan femur and its implications in orthopaedic surgery

Background : Numerous orthopaedic procedures are carried out on the proximal femur. For optimal hip function, these procedures must restore the anatomy of the proximal femur to as near normal as possible. There are currently no local studies that have described in detail the normal anatomy of the proximal femur and its implications in operations on the proximal femur. Objective : The aim of this study was to determine the neck-shaft angle, femoral neck anteversion angle, femoral neck width and femoral head diameter in adult femora, compare the results with other studied populations and examine the implications of the same in operations on the proximal femur. Methods : Femoral neck anteversion angle and the neck-shaft angle were determined from digital photographs of 70 cadaveric femora using an open-source image analysis software, ImageJ®(National Institutes of Health, Bethesda, Maryland). Femoral neck width and femoral head diameter were determined by measurement using a digital vernier caliper. The dimensions of available implants were searched from local suppliers of the implants. Results : Mean femoral neck-shaft angle was found to be 129.21o, while the mean femoral neck anteversion angle was found to be 23.06o. Mean neck-shaft angle was found to be 128.67o on the left while on the right side, it was 129.03o. This difference was not statistically significant. Mean femoral neck anteversion angle was found to be 23.97o on the left side, and 23.03o on the right side, but this difference was not statistically significant. Mean femoral neck width was found to be 29.36mm, with mean width of the left side being 28.67mm and that of the right being 29.36mm. The difference was not statistically significant. Mean femoral head diameter was 42.6mm, with mean diameter of the left side being 41.2mm and that of the right side being 42.6mm. The difference was not statistically significant. Conclusion : The current study has shown that the femoral neck-shaft and anteversion angles in the Kenyan femora vary from those of other populations. The available implants have angles which may not be suitable for a significant proportion of the local population. It would be prudent to avail a range of implants with different angles to improve the choices available to the surgeon when faced with a patient who requires an operation on the proximal femur.

The morphology of the proximal femur in the very elderly

Introduction. The population of the very elderly (i.e. ≥80 years of age) is growing rapidly due to demographic changes, an increased life expectancy, in particular. As a consequence, a 170% increase in the number of performed total hip arthroplasties (THAs) is projected for the next decades. Previous studies described the age-related changes in the morphology of the proximal femur, however, almost exclusively in subjects <80 years of age and using 2D X-rays. In THA the emphasis lies on reconstruction of the center of rotation (CoR) in order to preserve leg length, leg rotation and muscle tension (more precise: lever arm). The present study focuses on the reconstruction of the center of rotation (CoR) in the very elderly, with emphasis on the neck-shaft angle (NSA), the femoral neck anteversion angle (FNAA) and the mediolateral offset (ML offset). Furthermore, the effect of patient demographics such as gender, length and weight on the internal and external morphology of the proximal femur, the relationships between dimensions and angles on the proximal femur, and the effect of the internal morphology of the femoral canal on parameters describing the external geometry of the proximal femur were investigated. Methods. Ninety very elderly subjects (avg. 84.2 ± 3.6 years, range 80-105 years, 50M/40F) got a high-resolution CT-scan of their right femur (voxel size 1x1x1mm). Cortical bone models were derived from these scans using a specialized threshold algorithm in Materialise Mimics v10 and were further processed in Inus Technology Rapidform 2006. In order to classify the proximal femoral canal shape in stovepipe, normal or champagne flute the canal flare index (CFI) was measured according to Noble et al. Results. Compared to previous studies, the mean NSA (125.1 ± 5.5) and FNAA (10.0 ± 5.6) values found in the present study did not show notable differences. Based on the coronal CFI, the studied femora can be divided into stovepipe (23.3%) and non-stovepipe (76.7%). This percentage of stovepipe shaped proximal femoral canals is high compared to literature about younger populations. There are no differences in the external geometry between femora with a stovepipe or a non-stovepipe shaped canal. Furthermore, the FHD and the CoR-LTabsolute proved to be positively correlated (r=0.449) in the current study, the CoR-LTabsolute/FHD-ratio showed to be 1.17. The distance between the lesser trochanter and the center of rotation was both absolute (59.54 ± 5.76mm vs. 54.85 ± 6.31mm) and vertical (44.37 ± 6.77mm vs. 38.95 ± 7.41mm) larger in males than in females. Discussion. Based on the current study, no alternations in the external geometry of the current hip stem have to be made for an optimal elderly hip stem. However, due to advanced osteoporosis, this population of very elderly subjects contained more stovepipe shaped proximal canals based on their CFI, than younger populations. This has implications for hip stem design in the elderly. Namely, the proximal canal in which the hip stem is fixated is widened, while the external morphology remains the same. A hip stem with a thicker part for fixating in the shaft and the same external features as the currently used hip stem seems thus optimal in the very elderly (≥80yrs). Furthermore, a new equation for determining the head height, based on the diameter of the femoral head is suggested, which may be useful in hemiarthroplasty.