Rotational Alignment of the Knee is Different in Osteological Specimens with and without a Large Cam Deformity of the Proximal Femur

2017 ◽  
Vol 27 (4) ◽  
pp. 401-405
Author(s):  
Jeremy J. Gebhart ◽  
Jonathan J. Streit ◽  
Avi Goodman ◽  
Jordan Etscheidt ◽  
Douglas S. Weinberg ◽  
...  
Keyword(s):  
Femoral Head ◽  
Distal Femur ◽  
Alpha Angle ◽  
Tibial Tubercle ◽  
Cam Deformity ◽  
Whiteside’S Line ◽  
Posterior Condylar ◽  
Group 2 ◽  
Head Neck ◽  
Group 1

Purpose We studied a large osteological collection for differences in knee rotation based upon the presence or absence of a large cam deformity of the proximal femur. Methods We obtained 357 matched tibiae and femora from the Hamann-Todd Osteological Collection and measured: femoral head-neck alpha angle, anteroposterior axis (or Whiteside's line) at the distal femur relative to the posterior condylar axis, and position of the tibial tubercle with respect to the posterior condylar axis of the proximal tibia. We then divided these specimens into two groups based upon alpha angle <45° (Group 1, n = 73) or alpha angle >60° (Group 2, n = 122) and performed an independent samples t-test to evaluate for differences in measured parameters between groups using this subset of specimens. Results The mean alpha angles in Group 1 and 2 were 40.9° ± 3.3° and 67.0° ± 5.6°, respectively. Whiteside's line was externally rotated with respect to the posterior femoral condylar axis by a mean of 1.8° ± 6.8° in Group 1, vs. 3.0° ± 3.7° in Group 2 (p = 0.03). The tibial tubercle was externally rotated by a mean of 19.4° ± 6.8° in Group 1, versus 16.6° ± 5.1° in Group 2 (p = 0.003). Conclusions Specimens with femoral head-neck alpha angle >60° demonstrated greater external rotation of the distal femur and a more internally-rotated tibial tubercle compared to specimens with an alpha angle <45°. Differences in anatomic characteristics of the knee may play a role in the development of patellofemoral pain in patients with a large cam deformity.

Origin of Cam Morphology in Femoroacetabular Impingement

2017 ◽  
Vol 46 (2) ◽  
pp. 478-486 ◽  
Author(s):  
William Z. Morris ◽  
Ryan T. Li ◽  
Raymond W. Liu ◽  
Michael J. Salata ◽  
James E. Voos
Keyword(s):  
Femoral Head ◽  
Proximal Femur ◽  
Slipped Capital Femoral Epiphysis ◽  
Alpha Angle ◽  
Preliminary Evidence ◽  
Cam Deformity ◽  
Measurement Tools ◽  
Cam Morphology ◽  
Head Neck

Cam morphology of the proximal femur is an abnormal contour of the femoral head-neck junction present in approximately 15% to 25% of the asymptomatic population, predominantly in males. Alpha angle and femoral head-neck offset ratio are 2 objective measurement tools that define cam morphology. Both primary (idiopathic) and secondary cam deformity develops through distinct mechanisms. The cause of primary (idiopathic) cam morphology remains incompletely understood. Mounting evidence suggests that idiopathic cam morphology develops during adolescence through alterations in the capital femoral epiphysis in response to participation in vigorous sporting activity. While the exact cause of epiphyseal extension has not yet been determined, preliminary evidence suggests that epiphyseal extension may reflect a short-term adaptive response to provide stability to the physis at the long-term cost of the development of cam morphology. Commonly recognized causes of secondary cam deformity include frank slipped capital femoral epiphysis, Legg-Calve-Perthes disease, and deformity after fracture of the proximal femur. Recent studies also support subtle slipped capital femoral epiphysis as a unique and silent cause of a small percentage of subjects previously thought to have idiopathic cam deformity.

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

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0039
Author(s):  
Layla Haidar ◽  
Ryan Warth ◽  
Erinn Pemberton Annie Waite ◽  
Alfred Mansour
Keyword(s):  
Femoral Head ◽  
Alpha Angle ◽  
Three Dimensional ◽  
Neck Shaft Angle ◽  
Incremental Change ◽  
Observer Reliability ◽  
Angle Measurements ◽  
Femoral Version ◽  
Shaft Angle ◽  
Head Neck

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: see text][Figure: see text]

Ultrasound Determination of the Femoral Head-Neck Alpha Angle

2018 ◽  
Vol 44 (2) ◽  
pp. 495-501 ◽  
Author(s):  
D.J. Robinson ◽  
S. Lee ◽  
P. Marks ◽  
M.E. Schneider
Keyword(s):  
Femoral Head ◽  
Alpha Angle ◽  
Head Neck

Does Surgery Improve the Survival of Patients with Advanced Anaplastic Thyroid Carcinoma?

1998 ◽  
Vol 118 (5) ◽  
pp. 728-731
Author(s):  
WEN-TSOUNG LU ◽  
Jen-Der Lin ◽  
Hong-So Huang ◽  
Tzu-Chieh Chao
Keyword(s):  
Thyroid Carcinoma ◽  
Distant Metastases ◽  
Anaplastic Thyroid Carcinoma ◽  
Disease Group ◽  
Localized Disease ◽  
The Mean ◽  
Group 2 ◽  
Nonsurgical Patients ◽  
Head Neck ◽  
Group 1

Anaplastic thyroid carcinoma is one of the most lethal neoplasms, with poor prognosis being reported by most authors. The benefits of surgery for most cases of advanced disease remain controversial. In this study we asked the following question: Does surgical intervention alter outcomes for patients with advanced anaplastic thyroid carcinoma? Forty-six patients with advanced anaplastic thyroid carcinoma were analyzed. There were 20 patients with advanced localized disease (group 1), 15 of whom received surgery. Of the other 26 patients with evidence of distant metastases (group 2), 13 received surgery. For group 1 patients, the mean survival was 12.8 months versus 8.6 months in the surgical and nonsurgical subgroups ( p = 0.46). For group 2 patients, the mean survival was 3.5 months versus 2.8 months in the surgical and nonsurgical subgroups ( p = 0.72). These data suggest that surgery does not improve survival for patients with advanced anaplastic thyroid carcinoma. In conclusion, the mean survival showed no significant differences between surgical and nonsurgical patients ( p = 0.43). This study suggests that surgical resection does not improve the survival of patients with advanced anaplastic thyroid carcinoma. (Otolaryngol Head Neck Surg 1998;118:728–31.)

scholarly journals Standardized artificially created stable pertrochanteric femur fractures present more homogenous results compared to osteotomies for orthopaedic implant testing

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
J.F. Schader ◽  
I. Zderic ◽  
D. Gehweiler ◽  
J. Dauwe ◽  
K. Mys ◽  
...  
Keyword(s):  
Femoral Head ◽  
Bone Fractures ◽  
Orthopaedic Implant ◽  
Pertrochanteric Fractures ◽  
Femur Fractures ◽  
Biomechanical Behavior ◽  
Pertrochanteric Femur Fracture ◽  
Group 2 ◽  
Implant Testing ◽  
Group 1

Abstract Background With regard to biomechanical testing of orthopaedic implants, there is no consensus on whether artificial creation of standardized bone fractures or their simulation by means of osteotomies result in more realistic outcomes. Therefore, the aim of this study was to artificially create and analyze in an appropriate setting the biomechanical behavior of standardized stable pertrochanteric fractures versus their simulation via osteotomizing. Methods Eight pairs of fresh-frozen human cadaveric femora aged 72.7 ± 14.9 years (range 48–89 years) were assigned in paired fashion to two study groups. In Group 1, stable pertrochanteric fractures AO/OTA 31-A1 were artificially created via constant force application on the anterior cortex of the femur through a blunt guillotine blade. The same fracture type was simulated in Group 2 by means of osteotomies. All femora were implanted with a dynamic hip screw and biomechanically tested in 20° adduction under progressively increasing physiologic cyclic axial loading at 2 Hz, starting at 500 N and increasing at a rate of 0.1 N/cycle. Femoral head fragment movements with respect to the shaft were monitored by means of optical motion tracking. Results Cycles/failure load at 15° varus deformation, 10 mm leg shortening and 15° femoral head rotation around neck axis were 11324 ± 848/1632.4 ± 584.8 N, 11052 ± 1573/1605.2 ± 657.3 N and 11849 ± 1120/1684.9 ± 612.0 N in Group 1, and 10971 ± 2019/1597.1 ± 701.9 N, 10681 ± 1868/1568.1 ± 686.8 N and 10017 ± 4081/1501.7 ± 908.1 N in Group 2, respectively, with no significant differences between the two groups, p ≥ 0.233. Conclusion From a biomechanical perspective, by resulting in more consistent outcomes under dynamic loading, standardized artificial stable pertrochanteric femur fracture creation may be more suitable for orthopaedic implant testing compared to osteotomizing the bone.

scholarly journals Unusual apical femoral head deformity treated by hip arthroscopy and tunnel drilling through femoral head: a case report

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. i25-i33
Author(s):  
Boris Morattel ◽  
Nicolas Bonin
Keyword(s):  
Computed Tomography ◽  
Femoral Head ◽  
Alpha Angle ◽  
Central Compartment ◽  
Ligamentum Teres ◽  
Angle Measurement ◽  
Concomitant Treatment ◽  
Diagnostic Pitfall ◽  
Cam Deformity ◽  
Femoral Side

Abstract Femoro-acetabular impingement (FAI), is the result of an abnormal morphology of the hip joint. On the femoral side, asphericity of the head can be highlighted by an alpha angle measurement &gt;50° on computed tomography or MRI. However, some particular cephalic asphericities can make it difficult to measure the alpha angle, leading to a diagnostic pitfall. While in the classic cam effect, the deformity is peripheral and can be treated by arthroscopic femoroplasty, an apical head deformity remains a therapeutic challenge. We present the case of a 17-year-old male patient with a femoral head deformity, corresponding to an ISHA zone 6 overhang, significantly improved in everyday and sports life by arthroscopic trapdoor technique to resect the focal central deformity while enabling concomitant treatment of central compartment pathology, in this case, a hypertrophic ligamentum teres and femoral head chondral flap. Etiology of this femoral head deformity remains uncertain but could be a particular cam deformity, sequelae to pediatric disease or instability with repeated traction of the ligament teres on the femoral head apical insertion during cephalic growth.

scholarly journals Contribution to the method for determining femoral neck axis

2014 ◽  
Vol 142 (3-4) ◽  
pp. 178-183 ◽  
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.

scholarly journals Cam deformity and the omega angle, a novel quantitative measurement of femoral head-neck morphology: a 3D CT gender analysis in asymptomatic subjects

2016 ◽  
Vol 27 (5) ◽  
pp. 2011-2023 ◽  
Author(s):  
Vasco V. Mascarenhas ◽  
Paulo Rego ◽  
Pedro Dantas ◽  
Augusto Gaspar ◽  
Francisco Soldado ◽  
...  
Keyword(s):  
Femoral Head ◽  
Quantitative Measurement ◽  
3D Ct ◽  
Gender Analysis ◽  
Cam Deformity ◽  
Asymptomatic Subjects ◽  
Head Neck
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