The hip asphericity angle: a novel angle for measurement of Cam-FAI correction

Abstract The alpha angle is routinely used for the diagnosis and quantitative description of the Cam deformity of the hip. However, a reliable identification of the femoral neck axis as its reference line can be difficult. Moreover, most cam resections include a reduction of the femoral neck diameter with an automatic posteromedial angulation of the femoral neck axis. In consequence, the reference axes for the pre- and postoperative alpha angles are different, and a comparison of both angles underlies a systematic error to relatively higher postoperative alpha angles. In order to avoid this systemic error, we propose the hip asphericity (HA) angle with a reference axis independent of the amount of bony resection. Two retrospective groups were formed, a ‘femoroacetabular impingement (FAI) group’ that had hip arthroscopy for cam resection and a ‘Control group’ without cam deformity. The alpha and HA angles were measured by three examiners. The measurements were repeated 1 month later. In the FAI group, offset correction was calculated using both angles. Statistically significant differences for both the alpha and the HA angles were found between the control and the preoperative FAI group as well as between the preoperative and postoperative FAI groups. The HA angle-correction by a mean of 27.5° was significantly higher in comparison to the alpha angle correction by a mean of 25.4°. The intertester and intratester reliability of both angles were not significantly different. The HA angle is a new and reliable radiographic parameter for measuring cam deformity and proves superior in measuring cam correction.

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CAM-type femoroacetabular impingement in male elite junior cross-country skiers and non-athlete controls: a cross-sectional MRI study

BMJ Open Sport & Exercise Medicine ◽

10.1136/bmjsem-2019-000530 ◽

2019 ◽

Vol 5 (1) ◽

pp. e000530 ◽

Cited By ~ 1

Author(s):

Simen Andreas Sveen ◽

R Kyle Martin ◽

Eivind Alhaug ◽

Lars Engebretsen

Keyword(s):

High School ◽

Risk Factor ◽

High School Students ◽

Femoroacetabular Impingement ◽

Alpha Angle ◽

Ice Hockey ◽

Control Group ◽

School Students ◽

Cam Deformity ◽

Cross Country

ObjectivesCross-country (CC) skiing consists of two main techniques: classic and skating. Hip motion during the skating technique is similar to that in ice skating and is considered a risk factor for femoroacetabular impingement (FAI) in ice hockey players. We aimed to compare the presence of CAM-type FAI in a cohort of elite junior CC (EJCC) skiers with a control group of non-athlete (NA) high school students.MethodsObservational cohort study: EJCC skiers and NAs were recruited from a sports school and a regular high school, respectively. Baseline demographics and training history were obtained via a questionnaire. Bilateral hip MRI was performed and the alpha angle was measured in three planes. CAM deformity was defined as an alpha angle>55° on at least two MRI planes per hip.ResultsA total of 20 EJCC skiers and 10 NAs participated. All participants were male, aged 16–19 years. Average training volume was 528.10±68.34 hours per year for the EJCC skiers compared with 153.50±57.09 for the NAs (p<0.001). The prevalence of CAM deformity in at least one hip on MRI was 50% in both groups (10 CC skiers and 5 NAs). The average alpha angles were 52.4±6.1° in the EJCC group and 52.5±4.9° in the NA group (p=0.94).ConclusionRadiographic evidence of CAM-type FAI was not more common in the CC skiers compared with NAs. The type, rather than volume or intensity of training, maybe a more important risk factor for the development of CAM-type FAI in young athletes.

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Measuring the osteochondral connection of the femoral head and neck in patients with impingement femoroacetabulare by determining the angle of two alpha in lateral and anteroposterior hip radiographic images

Vojnosanitetski pregled ◽

10.2298/vsp110727038a ◽

2013 ◽

Vol 70 (3) ◽

pp. 259-266 ◽

Cited By ~ 1

Author(s):

Zoran Andjelkovic ◽

Desimir Mladenovic

Keyword(s):

Femoral Head ◽

Head And Neck ◽

Femoroacetabular Impingement ◽

False Negative ◽

Alpha Angle ◽

Control Group ◽

Pathophysiological Mechanism ◽

Simple Method ◽

Femoral Neck Axis ◽

Neck Junction

Background/Aim. Femoroacetabular impingement, a pathophysiological mechanism of small morphological changes of the hip leads to early arthritic changes. The aim of this study was to present a simple method for the quantification of femoral head and neck junction in patients with cam form of femoroacetabular impingement, in standardized anteroposterior and profile DUNN 90 radiograms of the hips. Methods. In standardized anteroposterior and profile DUNN 90 images of the hips we determined the angle of 2 alpha, defined by our own original method. We tested 141 hips in 81 patients without clinical signs of femoroacetabular impingement, and 153 hips in 76 patients with clinically clear signs of femoroacetabular impingement. Results. The value of the angle 2 alpha in anteroposterior hip radiograms was on average 113.7? for the patients with clinical symptoms of impingement, and 84.2? for the control group of patients (p ? 0.0001), and in DUNN 90 profile radiography of the hip, the value of 2 alpha angle in the patients group was 97.2?, and 74.6? in the control group (p ? 0.0001). The proposed method of determining the angle 2 alpha showed a high level sensitivity (97.8%) and specificity (98.7) and positive predictive value (98.6%). It was false positive in only 1.3%, and false negative in 2.12% of patients. Conclusion. Using standardized anteroposterior and profile radiographs of the hips, and without determination of femoral neck axis in patients with femoroacetabular impingement with the cam effect at the junction of the femoral head and neck, we proposed the method of measuring joint abnormalities of femoral head and neck junction, very capable to predict the disease development in an asymptomatic risk group of patients and high sensitive in the diagnosis of the disease in the group of patients.

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Contribution to the method for determining femoral neck axis

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh1404178a ◽

2014 ◽

Vol 142 (3-4) ◽

pp. 178-183 ◽

Cited By ~ 2

Author(s):

Zoran Andjelkovic ◽

Desimir Mladenovic ◽

Zoran Vukasinovic ◽

Stojanka Arsic ◽

Milorad Mitkovic ◽

...

Keyword(s):

Femoral Head ◽

Femoral Neck ◽

Small Sample Size ◽

Alpha Angle ◽

Head Rotation ◽

Small Sample ◽

Femoral Neck Axis ◽

Rotation Center ◽

Head Translation ◽

Head Neck

Introduction. Femoral neck axis plotting is of great significance in measuring parameters that define femoral head-neck junction sphericity in the group of patients with the femoroacetabular impingement. Literature methods of femoral neck axis determination have weaknesses associated with the risk of obtaining inaccurate values of certain parameters. Objective. Method of plotting of the femoral neck axis by two parallel lines that belong to the medial quarter of the femoral neck is proposed. Method was tested on the anatomic specimens and the respective radiograms. Methods. A total of 31 anatomic specimens of the proximal femur and respective radiographs were used, on which three axes of the femoral neck were plotted; accordingly, alpha angle value was determined and tested with corresponding parametric tests, with the measurement error of less than 5% and the strength of the applied tests of 80%. Results. Alpha angle values obtained by plotting femoral neck axis using the literature and methods we have proposed were not significantly different in our series, and, in more than a half of the specimens, the two axes overlapped each other. Conclusion. The advantage of the proposed method does not depend on the position of the femoral head rotation center in relation to the femoral neck, which favors proposed method for measuring the angles of femoral head sphericity in patients with the femoral head translation. Disadvantage of the study is a small sample size for valid conclusions about the applicability of this method in clinical practice.

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Morphometric study of proximal femur in fractured and non-fractured post menopausal women

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2017.v10i4.16761 ◽

2017 ◽

Vol 10 (4) ◽

pp. 313

Author(s):

Lopamudra Nayak ◽

Susmita Senapati ◽

Sitanshu Kumar Panda ◽

Prafulla Kumar Chinara

Keyword(s):

Femoral Neck ◽

Proximal Femur ◽

Morphometric Study ◽

Control Group ◽

Head Width ◽

Femoral Neck Axis ◽

Neck Shaft Angle ◽

The Mean ◽

Axis Length ◽

And Control

Objective: This study was conducted to investigate the risk of hip fracture using proximal femoral morphometry in fractured and nonfractured postmenopausal women.Methods: We conducted an observational cross-sectional study with 138 postmenopausal women (49 fractured and 89 nonfractured). The hip axis length (HAL), femoral neck axis length (FNAL), acetabular width (AW), femoral head width (FHW), femoral shaft width (FSW), and femoral neck shaft angle (FNSA) were measured in all cases by dual energy X-ray absorptiometry. We also studied the correlation between body mass index (BMI) with all the parameters in fractured and control groups.Results: The mean age, height, weight, and BMI were 61.24±3.23, 163.94±7.84 cm, 71.88±9.14 kg, and 26.72±2.78 kg/m², respectively, in fractured patients. In nonfractured patients the values were 59.73±5.32, 161.73±4.25 cm, 69.54±6.25 kg, and 26.74±2.23 kg/m² respectively. The mean HAL, FNAL, AW, FHW, FSW, and FNSA were 130.5±3.18 mm, 111.26±3.64 mm, 18.2±1.91 mm, 53.46±1.51 mm, 37.45±1.82 mm, and 132.76±3.15 degree incase group and 130.84±4.74 mm, 112.48±4.08 mm, 17.57±2.32 mm, 53.4±1.86 mm, 35.29±1.82 mm, and 128.76±3.6° in control group, respectively.Conclusion: The femoral parameters such as HAL, FNAL, AW, and FHW do not indicate any correlation between fractured and control groups, whereas FSW and FNSA were significantly higher in case group. The FNSA was having significant negative correlation with BMI in fractured group while that was having a significant positive correlation in the nonfractured group. This observation will be helpful in exploration of its clinical significance in proximal femoral fracture.Keywords: Proximal femur, Morphometry, Postmenopausal, Fracture.

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Anatomic Predictors of Sagittal Hip and Pelvic Motions in Patients With a Cam Deformity

The American Journal of Sports Medicine ◽

10.1177/0363546518755150 ◽

2018 ◽

Vol 46 (6) ◽

pp. 1331-1342 ◽

Cited By ~ 18

Author(s):

K.C. Geoffrey Ng ◽

Mario Lamontagne ◽

Jonathan R.T. Jeffers ◽

George Grammatopoulos ◽

Paul E. Beaulé

Keyword(s):

Femoral Neck ◽

Pelvic Incidence ◽

Alpha Angle ◽

Clinical Signs ◽

Sacral Slope ◽

Imaging Data ◽

Training Strategy ◽

Neck Shaft Angle ◽

Cam Deformity ◽

And Control

Background: As there is a high prevalence of patients with cam deformities and no ongoing hip dysfunction, understanding the biomechanical factors predicting the onset of symptoms and degenerative changes is critical. One such variable is how the spinopelvic parameters may influence hip and pelvic sagittal mobility. Hypothesis/Purpose: Pelvic incidence may predict sagittal hip and pelvic motions during walking and squatting. The purpose was to determine which anatomic characteristics were associated with symptoms and how they influenced functional hip and pelvic ranges of motion (ROMs) during walking and squatting. Study Design: Controlled laboratory study. Methods: Fifty-seven participants underwent computed tomography and were designated either symptomatic (n = 19, cam deformity with pain), asymptomatic (n = 19, cam deformity with no pain), or control (n = 19, no cam deformity or pain). Multiple femoral (cam deformity, neck angle, torsion), acetabular (version, coverage), and spinopelvic (pelvic tilt, sacral slope, pelvic incidence) parameters were measured from each participant’s imaging data, and sagittal hip and pelvic ROMs during walking and squatting were recorded using a motion capture system. Results: Symptomatic participants had large cam deformities, smaller femoral neck-shaft angles, and larger pelvic incidence angles compared with the asymptomatic and control participants. Discriminant function analyses confirmed that radial 1:30 alpha angle (λ1 = 0.386), femoral neck-shaft angle (λ2 = 0.262), and pelvic incidence (λ3 = 0.213) ( P < .001) were the best anatomic parameters to classify participants with their groups. Entering these 3 parameters into a hierarchical linear regression, significant regressions were achieved for hip ROM only when pelvic incidence was included for walking ( R2 = 0.20, P = .01) and squatting ( R2 = 0.14, P = .04). A higher pelvic incidence decreased walking hip ROM ( r = −0.402, P = .004). Although symptomatic participants indicated a trend of reduced squatting hip and pelvic ROMs, there were no significant regressions with the anatomic parameters. Conclusion: A cam deformity alone may not indicate early clinical signs or decreased ROM. Not only was pelvic incidence a significant parameter to classify the participants, but it was also an important parameter to predict functional ROM. Symptomatic patients with a higher pelvic incidence may experience limited sagittal hip mobility. Clinical Relevance: Patients with symptomatic femoroacetabular impingement showed a higher pelvic incidence and, combined with a cam deformity and varus neck, can perhaps alter the musculature of their iliopsoas, contributing to a reduced sagittal ROM. With an early and accurate clinical diagnosis, athletes could benefit from a muscle training strategy to protect their hips.

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Optimal Treatment of Cam Morphology May Change the Natural History of Femoroacetabular Impingement

The American Journal of Sports Medicine ◽

10.1177/0363546520949541 ◽

2020 ◽

Vol 48 (12) ◽

pp. 2887-2896

Author(s):

Benjamin G. Domb ◽

Shawn Annin ◽

Jeffrey W. Chen ◽

Cynthia Kyin ◽

Philip J. Rosinsky ◽

...

Keyword(s):

Natural History ◽

Alpha Angle ◽

Treated Group ◽

Harris Hip Score ◽

Control Group ◽

Cam Deformity ◽

History Of ◽

Modified Harris Hip Score ◽

Cam Morphology

Background: There is debate in the literature whether cam morphology is associated with increased risk for hip osteoarthritis. The capability of femoroplasty to alter the natural history of cam morphology is still in question. Purpose: To (1) investigate the correlation between cam morphology and damage to the articular cartilage and (2) assess whether correction of the cam morphology affects survivorship of the joint, progression to arthroplasty, and functional patient-reported outcome scores. Study Design: Cohort study; Level of evidence, 3. Methods: Data were prospectively collected for patients presenting for hip arthroscopy between February 2008 and April 2017. Cases were divided into 3 groups: control group with an alpha angle <50° pre- and postoperatively, treated group with an alpha angle >55° preoperatively and <50° postoperatively, and a group with an alpha angle >55° pre- and postoperatively. All patients had minimum 2-year postoperative follow-up for the modified Harris Hip Score, the Non-arthritic Hip Score, and visual analog scale for pain. Conversion to total hip arthroplasty was recorded. Results: A 1:1:1 match successfully yielded 98 hips for each group. Follow-up time was 50.77 ± 24.60 months (mean ± SD). The pre- and postoperative mean alpha angles were 45.2°± 3.4° and 40.6°± 4.3° in the control group, respectively; 66.2°± 8.4° and 42.3°± 5.9° in the treated group; and 68.5°± 9.4° and 61.4°± 7.6° in the alpha >55° group. Intraoperatively, the alpha >55° and treated groups had greater acetabular cartilage damage than the control group ( P = .0245 and P = .0036, acetabular labrum articular disruption, respectively; P = .0347 and P = .0211, acetabular Outerbridge). The alpha >55° group achieved the patient acceptable symptomatic state for the modified Harris Hip Score (58.2%) significantly less than the treated (75.5%; P = .0100) and control (73.5%; P = .0239) groups. Progression to arthroplasty was significantly higher in the alpha >55° group (n = 17) when compared with the control (n = 8) and treated (n = 10) groups ( P = .0034 and P = .0338, respectively). Conclusion: Cam deformity was associated with higher-grade damage of the acetabular articular cartilage. An alpha angle >55° after surgery was associated with lower native hip joint survivability and less successful functional outcomes when compared with that of treated cam deformity as well as no deformity. These data suggest that correcting the cam deformity may positively affect the natural history of these patients.

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CUSTOMIZED GUIDE FOR FEMORAL COMPONENT POSITIONING IN HIP RESURFACING ARTHROPLASTY

Acta Ortopédica Brasileira ◽

10.1590/1413-785220172502167422 ◽

2017 ◽

Vol 25 (2) ◽

pp. 103-106

Author(s):

Chaturong Pornrattanamaneewong ◽

Rapeepat Narkbunnam ◽

Keerati Chareancholvanich

Keyword(s):

Femoral Neck ◽

Three Dimensional ◽

Posterior Part ◽

Image Intensifier ◽

Hip Resurfacing ◽

Three Dimensional Model ◽

Level Of Evidence ◽

Hip Resurfacing Arthroplasty ◽

Femoral Neck Axis ◽

Resurfacing Arthroplasty

ABSTRACT Objective: To prove the accuracy of a customized guide developed according to our method. Methods: This customized guide was developed from a three-dimensional model of proximal femur reconstructed using computed tomography data. Based on the new technique, the position of the guide pin insertion was selected and adjusted using the reference of the anatomical femoral neck axis. The customized guide consists of a hemispheric covering designed to fit the posterior part of the femoral neck. The performance of the customized guide was tested in eight patients scheduled for total hip arthroplasty. The stability of the customized guide was assessed by orthopedic surgeons. An intraoperative image intensifier was used to assess the accuracy. Results: The customized guide was stabilized with full contact and was fixed in place in all patients. The mean angular deviations in relation to the what was planned in anteroposterior and lateral hip radiographs were 0.5º ± 1.8º in valgus and 1.0º ± 2.4º in retroversion, respectively. Conclusion: From this pilot test, the authors suggest that the proposed technique could be applied as a customized guide to the positioning device for hip resurfacing arthroplasty with acceptable accuracy and user-friendly interface. Level of Evidence IV, Cases Series.

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A radiographic and anatomic study of caudolateral curvilinear osteophytes on the canine femoral neck

Veterinární Medicína ◽

10.17221/2/2016-vetmed ◽

2017 ◽

Vol 62 (No. 6) ◽

pp. 315-324 ◽

Cited By ~ 1

Author(s):

L. Pyszkova ◽

M. Pyszko ◽

V. Paral ◽

F. Tichy ◽

M. Kyllar

Keyword(s):

Femoral Neck ◽

Proximal Femur ◽

Hip Dysplasia ◽

Distal Femur ◽

Alpha Angle ◽

Anatomic Study ◽

Significant Relationships ◽

Beta Angle ◽

Study Support ◽

Canine Hip Dysplasia

Caudolateral curvilinear osteophytes (CCOs) are considered to be an important finding for the early detection of canine hip dysplasia. The objective of this study was to determine the association between the radiographic and anatomic appearance of CCOs, and to determine whether CCOs are indicative of osteoarthritis. One hundred canine femurs were used to determine the topographical location of CCOs on the femoral neck, and the anatomic and radiographic presence of CCOs and their association with weight, sex, osteoarthritis, and femoral morphometry. Three angles were calculated to assess femoral conformation. The alpha angle and gamma angle described the angulation of the proximal femur and femoral neck, respectively. The beta angle described the angulation of the distal femur. Anatomic CCO was not detected in four femurs. No radiographic CCO was detected in 35 femurs and osteoarthritis changes were not found in 30 femurs. Statistically significant relationships were observed between anatomic CCO, alpha angle, and gamma angle. Statistically significant associations were observed between radiographic CCO, alpha angle, and gamma angle. The results of this study support an association between radiographic CCO on the femoral neck and osteoarthritis changes in the proximal femur. It can also be concluded that CCOs develop in association with femoral neck angulation, and may therefore be considered as an adaptation to the forces created by body weight that act through the femoral neck.

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Adverse plasma fatty acid composition in patients with femoral neck fracture1

Canadian Journal of Physiology and Pharmacology ◽

10.1139/cjpp-2019-0249 ◽

2020 ◽

Vol 98 (2) ◽

pp. 61-66

Author(s):

Aleksandra Arsic ◽

Goran Pesic ◽

Snjezana Petrovic ◽

Aleksandar Matic ◽

Jovana Jeremic ◽

...

Keyword(s):

Femoral Neck ◽

Thiobarbituric Acid ◽

The Elderly ◽

Nutritional Intervention ◽

Femoral Neck Fractures ◽

Fracture Repair ◽

Elderly Subjects ◽

Control Group ◽

Total N ◽

Tnf Α

Our study aimed to examine the status of plasma fatty acids (FAs), inflammatory markers, and lipid peroxidation in patients with femoral neck fractures. The study included 20 patients (64–86 years) with femoral neck fractures indicated for surgery and a control group of 17 elderly subjects without fractures or serious chronic diseases. Plasma was obtained during the first 12 h postfracture and presurgery and 7 days postop. Compared to the control, patients had significantly higher saturated FA (SFA) and monounsaturated FA as well as increased TNF-α and IL-6. Opposite to that, levels of individual and total n-6 polyunsaturated FA (PUFA), individual and total n-3 PUFA, n-6/n-3 ratio, and levels of thiobarbituric acid reactive substances (TBARS) were markedly lower in the patient than in the controls. On the seventh day after the surgery, we showed a further rise in the SFA, oleic acid, and TNF-α and reductions of n-6 PUFA and IL-6. Taken together, our results suggest that altered FA status, especially reduced PUFA, may influence hip fracture repair and even contribute to femoral fracture susceptibility in the elderly. A potential benefit from nutritional intervention with PUFA in prevention and (or) fracture healing should be considered.

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