The Modified Femoral Neck-Shaft Angle: Age- and Sex-Dependent Reference Values and Reliability Analysis

Background. The femoral neck-shaft angle (NSA) is of high importance for the diagnostics and treatment of various conditions of the hip. However, rotational effects limit its precision and applicability using plain radiographs. This study introduces a novel method to measure the femoral NSA: the modified NSA (mNSA), possibly being less susceptible against rotational effects compared to the conventional NSA.Patients and Methods. The method of measurement is described and its applicability was tested in 400 pelvis computed tomography scans (800 hips). Age- and gender-dependent reference values are given and intra- and interrater reliability are analyzed.Results. The mean age of all 400 patients (800 hips) was 54.32 years (18–100, SD 22.05 years). The mean mNSA was 147.0° and the 95% confidence interval was 146.7°–147.4°. Differences of the mNSA between sexes, age groups, and sides were nonsignificant. The absolute difference between NSA and mNSA was 16.3° (range 3–31°; SD 4.4°); the correlation was high (0.738;p<0.001). Overall, the intra- and interrater reliability were excellent for the mNSA.Interpretation. We introduced a novel concept for the analysis of the neck-shaft angle. The high reliability of the measurement has been proven and its robustness to hip rotation was demonstrated.

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Valgus Osteotomy Outcome for Treating Femoral Neck Nonunion in Young and Active Patients

Journal of Research in Orthopedic Science ◽

10.32598/jrosj.8.2.400.1 ◽

2021 ◽

Vol 8 (2) ◽

pp. 65-70

Author(s):

Kaveh Gharanizadeh ◽

◽

Hamed Tayyebi ◽

Abbas Esmaeli ◽

Maziar Rajei ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Femoral Neck ◽

Hip Arthroplasty ◽

Limb Length Discrepancy ◽

Osteotomy Site ◽

Valgus Osteotomy ◽

Neck Shaft Angle ◽

Shaft Angle ◽

The Mean

Background: Femoral neck fracture nonunion is a frequent and challenging complication, with several surgical options. Objectives: The present study reported the outcome of valgus osteotomy for treating femoral neck nonunion in patients aged <65 years. Methods: This case series research included young patients who underwent valgus osteotomy for treating femoral neck nonunion or device failure of the index surgery. The fixation of the osteotomy site was performed using either a dynamic hip screw or a fixed angle blade. The union of the neck and osteotomy site (subtrochanteric region) was evaluated by monitoring callus formation in the postoperative radiographs. Limb length discrepancy, Pauwels’ angle, and the neck-shaft angle were evaluated before the surgery and at the last follow-up. Postoperative complications were extracted from the explored patients’ profiles. Results: Twenty patients with a Mean±SD age of 27.2±10.8 years were examined in this study‎. The Mean±SD follow-up time of the patients was 6.1±3.9 years. The femoral neck was united in 18 patients in a Mean±SD period of 5.1±2.3 months. The Mean±SD limb length discrepancy was measured as 1.3±0.8 cm before and 0.5±0.7 cm after the ‏osteotomy. The Mean±SD Pauwels’ angle was calculated as 65.5±16.9º before and 32.4±16.2º after the osteotomy. The Mean±SD neck-shaft angle was computed to be 121.9±22.8º before and 144.5±17.7º after the osteotomy. Revision surgery was performed for 6 (30%) patients. This measure included device removal in 4 and total hip arthroplasty in 2 patient. Conclusion: Valgus osteotomy is a safe and efficient technique for managing femoral neck nonunion. Therefore‎, this approach is suggested as a good alternative for total hip arthroplasty, particularly in young and active patients‎.

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Medial Proximal Femoral Angle better than Neck-Shaft Angle? Influence of Rotation on the Anteroposterior Radiograph

The Journal of Hip Surgery ◽

10.1055/s-0037-1607978 ◽

2017 ◽

Vol 01 (03) ◽

pp. 146-151 ◽

Cited By ~ 3

Author(s):

Julian Fürmetz ◽

Florian Wolf ◽

Ekkehard Euler ◽

Peter Thaller ◽

Nikolaus Degen

Keyword(s):

External Rotation ◽

Three Dimensional ◽

Image Data ◽

Basic Research ◽

Absolute Difference ◽

Level Of Evidence ◽

Femoral Torsion ◽

Neck Shaft Angle ◽

Shaft Angle ◽

The Mean

AbstractNeck-shaft angle (NSA) and medial proximal femoral angle (MPFA) describe the geometry of the proximal femur, but they are influenced by rotation. The MPFA is closer to the right angle and therefore assumed to be less influenced. This hypothesis was tested with a mathematical approach to compare the effects of rotation and their clinical relevance on both angles. We developed a three-dimensional (3D) geometrical model representing projectional radiography of the femoral axes under rotation and derived a mathematical equation. For validation purposes, we experimentally simulated projectional radiography and compared the results to those of the equation (five different inclinations of the femoral neck (IFN) each in 13 different rotations). The validated equation was used to determine the influence of rotation (–60° to +60°) on normal valued NSA and MPFA. The mean absolute difference between calculated and experimentally measured values was 0.6° (standard deviation [SD] 0.5; 0.0–2.2). The mean calculated difference between true and projected NSA was 7.1° (SD 7.1; 0.0–22.0), and for the MPFA, it was –1.9° (SD 2.2; –7.4 to 0.0). Clinically relevant deviations (≥5°) occurred at ≥30° external or ≥ 40° internal rotation for the NSA, for the MPFA at 60° external rotation. Mathematical modeling of radiographic projection of the IFN is possible to a high level of accuracy. Our results indicate that the NSA is significantly more susceptible to deviations caused by rotation than the MPFA. Clinicians must be aware of rotational influences in radiographic projection and possibly should use the MPFA instead of the NSA. The rotational influence during X-ray imaging must be controlled accurately, and femoral torsion should be quantified in computed tomography/magnetic resonance imaging (CT/MRI) scans if possible. 3-D bone models reconstructed from digital image data can be a future option for measuring true angles. Level of evidence was basic research.

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AGE AND GENDER DIFFERENCES IN MODIFIED FEMORAL NECK-SHAFT ANGLE: AN MRI BASED OBSERVATIONAL STUDY

10.36106/ijsr/8420737 ◽

2020 ◽

pp. 1-4

Author(s):

Najamul Huda ◽

Ankur Agarawal* ◽

Man Mohan Sharma ◽

Saurabh Agarwal

Keyword(s):

Femoral Neck ◽

Age Group ◽

Age And Gender ◽

Neck Shaft Angle ◽

Mri Scans ◽

Shaft Angle ◽

The Mean ◽

The Difference ◽

Gender Based ◽

And Gender

Background: Femoral neck-shaft angle has its importance in describing biomechanics of hip. Measurement methods like plain radiography and CT scans have its limitations. The modied neck-shaft angle (mNSA) drawn on MRI scans is less susceptible to rotational effects and is more reliable for getting normal values. The present study was undertaken to assess the neck shaft angle on MRI and establish differences according to age and gender. Methods: Total 200 adults were recruited and equally distributed under four study cohorts according to age and gender. MRI of hip joint was analysed and mNSA was measured using pre-dened axial lines and landmarks. Results: The mean age of the participants was 49.76±18.184 years (18 to 87 years). The mean mNSA was 147.855o. Males had signicantly higher mean mNSA (149.93±6.61)o than females (145.78±5.71)o. Though the younger age group (<60 years) had higher mNSA values (148.32±6.65) than older (> 60years) age group (147.3900±6.35), the difference was not statistically signicant. Conclusions: We conclude that gender-based variation exists in the population with the higher values of mNSAin males as compared to females in any age group. The age based difference is also present, but it is not signicant. Neck shaft angle calculated on the MRI has the advantage that it is unaffected by rotation of the hip and is radiation free. The orthopaedic surgeons can use the mNSAfor the diagnosis and planning surgeries around hip, for designing implants and prosthesis. It can also be of help for the forensic anthropologists and to the anatomists. Multicentric studies may be undertaken to include a larger population.

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Assessment of Femoral Neck-shaft Angle on Plain X-rays and its Clinical Implications

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2021/v33i47b33191 ◽

2021 ◽

pp. 841-844

Author(s):

N. Adhishwar Kumaran ◽

B. Jagadeesh ◽

Ashok Kumar ◽

K. P. Niveditha

Keyword(s):

Femoral Neck ◽

Neuromuscular Disorders ◽

Local Population ◽

Tertiary Care ◽

X Rays ◽

College Hospital ◽

Cross Sectional ◽

Neck Shaft Angle ◽

Shaft Angle ◽

The Mean

Background: Femoral neck-shaft angle is an important parameter for evaluating the biomechanics of the hip joint. It plays a pivotal role in surgeries for developmental dysplasia of the hip, neuromuscular disorders of the lower limb, proximal femoral fractures, Total Hip Arthroplasty, Perthes disease etc., It is also considered to hold an extensive bearing while designing orthopaedic implants. Aim: This study aimed to evaluate the femoral neck-shaft angle of proximal femur on plain radiographs of our local population Study Design: Retrospective study Methods: This cross-sectional study was done at Saveetha medical college hospital, a tertiary care institute in Chennai. 50 pelvic X-rays of patients aged between 30 to 70 who presented to the outpatient or emergency care department were used in the study. Using a goniometer the femoral neck shaft angle was measured in the plain X - ray. Results: The mean age of the population in our study was 47.12. And the mean femoral neck shaft was 132.6 in males and 124.9 in females.

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A COMPARATIVE STUDY OF NECK SHAFT ANGLE OF FEMUR IN CENTRAL INDIAN POPULATION

10.36106/paripex/1402452 ◽

2021 ◽

pp. 1-3

Author(s):

Vivek Kumar ◽

Vivekanand Murlidhar Gajbhiye

Keyword(s):

Femoral Neck ◽

Indian Population ◽

Femoral Shaft ◽

Mean Value ◽

Developmental Dysplasia ◽

Neck Shaft Angle ◽

Geographical Variations ◽

Shaft Angle ◽

The Mean ◽

The Right

Background: In the fields of forensics, anthropology, orthopaedics, and human kinematics, the thigh bone femur is widely studied. The clinical significance of the femoral neck shaft angle lies in the diagnosis, treatment and monitoring of femoral neck fractures, trochanteric fractures, slipped upper femoral epiphysis, and hip developmental dysplasia. Objective: The present study was conducted to compare the NSA disparity between femurs on both sides and to compare the NSA with the Western and Indian population sizes of different regions. This research therefore leads to Indian data on these parameters. Materials and Methods: A total of 150 (75 right and 75 left) dry femur were used for measuring the neck shaft angle. Unpaired t-test was used to compare right and left femora. Results: The mean value of neck shaft angle was 126.04±5.05°. It ranges between 1130 to 1360. The mean value of right side was 125.92±4.9° and left side was measured 127.43±5.2°. There was no significant correlation between right and left neck shaft angle. Conclusion: The mean left femoral neck shaft angle was higher than the right femoral shaft in the present analysis, but the values were not statistically important. The angle of the neck shaft was lower than most studies in the Western population, but it was similar to most other studies in India. In the Indian population, geographical variations in the angle of the neck shaft also occur. In the field of orthopaedic surgery and anthropometry, this research will be of benefit.

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Radiographic Assessment of the Proximal Femoral Anatomy in An Indigenous African Adult Population

International Journal of Anatomy and Research ◽

10.16965/ijar.2021.140 ◽

2021 ◽

Vol 9 (3.1) ◽

pp. 8034-8039

Keyword(s):

Femoral Neck ◽

Proximal Femur ◽

Adult Population ◽

Femoral Offset ◽

Femoral Neck Axis ◽

Neck Shaft Angle ◽

Shaft Angle ◽

The Mean ◽

Axis Length ◽

Neck Diameter

Background: Hip surgeries such as fracture fixation, corrective osteotomy, hemiarthroplasty, or total hip arthroplasty require accurate preoperative templating for a successful outcome. Such templating is done using the proximal femur and the acetabulum radiographs, depending on the planned surgery. Understanding the normal radiographic anatomy of the proximal femur is crucial to differentiate a normal from pathological anatomy. Proximal femoral anatomic indices include the femoral head diameter, femoral neck diameter, femoral neck length, femoral offset, femoral neck axis length and the femoral neck-shaft angle. Aim: This study assesses and establishes the average values of the proximal femoral anatomy in an indigenous African adult population. Method: This cross-sectional study examined 190 normal anteroposterior (AP) radiographs of the pelvis. The mean age, weight and height of the subjects were obtained. The following proximal femoral anatomic parameters were measured: femoral neck length (FNL), femoral neck diameter (FND), femoral head diameter (FHD), femoral neck-shaft angle (FNSA), femoral offset (FO) and femoral neck axis length (FNAL). The authors compared the mean difference of the parameters between the genders and the age categories and assessed the parameter correlations with the patients’ weight and height. Results: Males constituted 63 (33.2%) of the study population. The mean age of the subjects was 51.46 years (SD = 16.37). The mean weight was 76.13 kg, while the mean height was 1.62 m. The mean values of the proximal femoral parameters were as follows: FNL 4.52cm, FND 3.42cm, FHD 4.76cm, FNSA 132.960, FO 4.09cm, and FNAL 10.34cm. Males have a significantly higher mean value in all the parameters except the FO. None of the parameters showed any significant difference among the age categories except the FNL. A post-hoc analysis showed that the difference in the FNL lies between the young and the elderly age groups. The subjects’ height correlated with all the parameters except FNSA, while the weight correlated with the FND, FNSA and FNAL. Conclusion: The proximal femoral anatomy in Africans differed from those published in foreign literature. This knowledge is crucial for implant manufacturing companies and preoperative templating for hip surgeries. KEY WORDS: Proximal femur, Anatomy, Black population.

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Is the femoral neck-shaft angle an independent risk factor for hip fractures? An observational study

International Journal of Research in Orthopaedics ◽

10.18203/issn.2455-4510.intjresorthop20194811 ◽

2019 ◽

Vol 5 (6) ◽

pp. 1032

Author(s):

Bernard O. Obande ◽

Emmanuel C. Iyidobi ◽

Gabriel O. Eyichukwu ◽

Cajetan U. Nwadinigwe ◽

Remigus T. Ekwunife ◽

...

Keyword(s):

Hip Fracture ◽

Femoral Neck ◽

Hip Fractures ◽

Predictor Variable ◽

Outcome Variable ◽

Control Group ◽

Neck Shaft Angle ◽

Increased Risk ◽

Shaft Angle ◽

The Mean

Background: The femoral neck-shaft angle (FNSA) has been implicated in the aetiology of hip fractures. The longer moment arm of a higher FNSA has been theorized to impart a greater deforming force to the greater trochanter, which may cause a hip fracture.Methods: A prospective study that involves adults with hip fractures and a control group matched for age and sex. The FNSA of both groups were measured on an anteroposterior X-ray of the pelvis. The mean FNSA were compared with a paired samples t-test, and a binary logistic regression analysis was run with the FNSA as a predictor variable and the presence of hip fracture as an outcome variable.Results: A total of 150 patients were recruited for the study, 75 per group. The mean age of patients with hip fractures was 71.30 years (S.D.=14.34), and that of the control group was 73.94 years (S.D.=12.55), p=0.264. The mean FNSA of the study group was 133.96o (S.D.=3.77) while that of the control group was 131.05o (S.D.=3.86), p<0.001. Increasing FNSA imparts a higher risk of having a hip fracture, O.R.=1.24 (95% C.I, 1.12-1.37).Conclusions: Individuals with higher FNSA demonstrated a significantly increased risk of developing hip fractures. However, the exact cut-off point of the FNSA, which predisposes to the risk of these fractures, remains to be elucidated.

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Evaluation of femoral neck shaft angle on plain radiographs and its clinical implications

International Journal of Research in Orthopaedics ◽

10.18203/issn.2455-4510.intjresorthop20164173 ◽

2016 ◽

Vol 2 (4) ◽

pp. 383 ◽

Cited By ~ 1

Author(s):

Subodh Kumar Pathak ◽

Pritam Maheshwari ◽

Prahlad Ughareja ◽

Daksh Gadi ◽

Prashanth Raj M. ◽

...

Keyword(s):

Femoral Neck ◽

Indian Subcontinent ◽

Slipped Capital Femoral Epiphysis ◽

Orthopedic Implants ◽

Developmental Dysplasia ◽

Neck Of Femur ◽

Neck Shaft Angle ◽

Shaft Angle ◽

The Mean ◽

Picture Archiving And Communication

Background: The femoral neck-shaft angle is the measurement of the angle formed between the oblique oriented neck with the vertical shaft and is an important anatomic measurement for the evaluation of biomechanics of hip. The neck shaft angle is important in surgeries that involve the neck of femur, Intertrochanteric fractures, slipped capital femoral epiphysis, and developmental dysplasia of hip. Different variation of neck shaft angle has been seen in different literature and all the orthopedic implants are designed according to the values of the western literature which is different from the Indian subcontinent.Methods: Pelvic radiographs of patients who presented to Accident and emergency care or the outpatient department were used in the study 110 patients radiographs were assessed in the study. There were 55 males and 55 females in our study. The mean age for males was 46.5 years and that for females was 43.2 years. The pelvis radiographs were studied for neck shaft angle .The measurements were performed bilaterally on the digital screen using the PACS (picture archiving and communication system) with handheld 360 degree goniometer.Results: The mean neck shaft angle in our study was129.26 degree for males and 126.62 degree for females .The overall mean neck shaft angle in 110 radiographs was 128.60 degree. Conclusions: We conclude that consideration of neck shaft angles in orthopedics surgery and designing of implant can give more angle options for the surgeons which can improve the overall prognosis of the patient.

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The association between femoral neck shaft angle and degenerative disease of the hip in a cadaveric model

Hip International ◽

10.1177/11207000211013029 ◽

2021 ◽

pp. 112070002110130

Author(s):

Leigh-Anne Tu ◽

Douglas S Weinberg ◽

Raymond W Liu

Keyword(s):

Femoral Head ◽

Femoral Neck ◽

Hip Osteoarthritis ◽

Volume Ratio ◽

Femoral Head Coverage ◽

Neck Shaft Angle ◽

Hip Arthritis ◽

Femoral Version ◽

Shaft Angle ◽

The Impact

Background: While the influences of acetabular dysplasia and overcoverage on hip arthritis have been studied, the impact of femoral neck-shaft angle on hip arthritis is much more poorly understood. The purpose of this study is to determine if a relationship exists between neck shaft angle and the development of osteoarthritis, a better understanding of which would be useful to surgeons planning osteotomies about the hip. Methods: 533 cadaveric femora and acetabulae (1066 total) from the Hamann-Todd Osteological Collection (Cleveland, OH) were acquired. We measured true neck shaft angle using an AP photograph with the femoral neck parallel to the table. Femoral head volume to acetabular volume ratio, representing femoral head coverage, as well as femoral version were utilised. Correlation between neck shaft angle, femoral version, femoral head coverage and osteoarthritis were evaluated with multiple regression analysis. Results: The mean age and standard deviation was 56 ± 10 years. There were 64 females (12%) and 469 males. There were 380 Caucasians (71%) and 153 African-Americans. Mean femoral version was 11° ± 12° and mean true neck shaft angle was 127.7° ± 5.9° There was a strong correlation between age and arthritis (standardised beta 0.488, p < 0.001). There was a significant correlation between increasing true neck shaft angle and decreasing hip arthritis (standardised beta -0.024, p = 0.038). In the femoral head overcoverage subset, increasing true neck shaft angle was still significantly associated with decreasing hip arthritis (standardised beta −0.088, p = 0.018), although this relationship was not significant with femoral head undercoverage subset. Conclusions: With sufficient acetabular coverage, a relative increase in femoral neck shaft angle within the physiologic range is associated with decreased hip osteoarthritis. Clinical relevance: An understanding of the relationship between femoral neck shaft angle and hip osteoarthritis could be useful for surgeons planning pelvic or proximal femur osteotomies in children.

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Simultaneous Morscher’s osteotomy and arthroscopic debridement in the management of Legg–Calvé–Perthes disease: a case report and literature review

Journal of Hip Preservation Surgery ◽

10.1093/jhps/hnab017 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. i4-i8

Author(s):

Batool Bosakhar ◽

Hassan Baldawi ◽

Kathy Liu ◽

Olufemi R Ayeni ◽

Waleed Kishta

Keyword(s):

Case Report ◽

Literature Review ◽

Femoral Neck ◽

Perthes Disease ◽

Labral Repair ◽

Coxa Vara ◽

Neck Shaft Angle ◽

Shaft Angle ◽

Outcome Tool

Abstract There is a lack of consensus around optimal surgical management for Legg–Calvé–Perthes Disease (LCPD). This case report discusses the benefits of combining arthroscopic femoral neck osteochondroplasty and labral repair with Morscher’s Osteotomy (MO) for LCPD. S.A. is a 17-year-old female diagnosed with LCPD at the age of 6 years and has long-standing right hip symptoms. An arthroscopic femoral neck osteochondroplasty and labral repair followed by MO was performed. The pre-operative and 8 months post-operative International Hip Outcome Tool (iHOT-12) scores were 16.3 and 79.8 out of 100, respectively, indicating better quality-of-life. Also, the femoral neck-shaft-angle (NSA) changed from 120 pre-operative to 138.7 post-operative to represent the correction of coxa vara. The literature review revealed no published reports describing combined MO with hip arthroscopic interventions in managing LCPD. Combined arthroscopic femoral neck osteochondroplasty (with labral repair) and MO provides high patient satisfaction and improves radiographic parameters in patients with LCPD.

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