“Functional Retroversion” of the Femoral Head in Legg-Calvé-Perthes Disease and Epiphyseal Dysplasia: Analysis of Head-Neck Deformity and Its Effect on Limb Position Using Three-Dimensional Computed Tomograp

1997 ◽  
Vol 17 (2) ◽  
pp. 240-246 ◽  
Author(s):  
Hui Taek Kim ◽  
Dennis R. Wenger
Keyword(s):  
Femoral Head ◽  
Three Dimensional ◽  
Perthes Disease ◽  
Limb Position ◽  
Epiphyseal Dysplasia ◽  
Head Neck

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]

A Finite Element Investigation into the Effects of Head Size and Trunnion Design on the Micromotion at the Head-Neck Interface in THR

2014 ◽  
Vol 553 ◽  
pp. 287-292
Author(s):  
W. Theodore ◽  
J. Pierrepont ◽  
Q. Li ◽  
B. Miles
Keyword(s):  
Finite Element ◽  
Femoral Head ◽  
Case Reports ◽  
Three Dimensional ◽  
Femoral Stem ◽  
Element Model ◽  
Head Size ◽  
Metal Head ◽  
The Stability ◽  
Head Neck

The modularity of femoral head and femoral stem provides many benefits to surgeons. However, case-reports have shown failure in large head Metal-on-Metal hip replacement due to trunnionosis. The exact causes of trunnionosis are not yet identified but the additional interface at the modular joint seems to be a contributing factor. In this study, a three dimensional non-linear finite element model was created to analyse the effects of head size and trunnion design on the micromotion at the head-neck interface. Four different metal head sizes and two trunnions designs and materials were used in the model. The femoral heads were assembled onto the trunnions with 7kN axial force and one cycle of gait load was applied to the head after assembly. The study showed that the micromotion was substantially increased in femoral head larger than 36mm. Trunnions material has greater effect on micromotion than trunnion design, particularly with the larger head sizes. The stability at the modular junction is important. Our findings suggest that there is a limit of assembly force to maintain enough stability on the joint; beyond this limit; the maximum micromotion will not be affected.

Bilateral Femoral Head Dysplasia and Osteochondritis

1988 ◽  
Vol 29 (6) ◽  
pp. 705-709 ◽  
Author(s):  
P. E. Andersen ◽  
K. Schantz ◽  
J. Bollerslev ◽  
P. Justesen
Keyword(s):  
Genetic Counseling ◽  
Femoral Head ◽  
Epidemiologic Study ◽  
Perthes Disease ◽  
Radiologic Findings ◽  
Population Prevalence ◽  
Spinal Lesion ◽  
Epiphyseal Dysplasia ◽  
Treatment Prognosis ◽  
Distinguishing Features

Multiple epiphyseal dysplasia tarda (MEDT) and spondylo-epiphyseal dysplasisa tarda (SEDT) are genetically transmitted conditions affecting the hips, which may resemble bilateral Legg-Perthes disease (LPD). Misdiagnoses are not uncommon, with serious implications for treatment, prognosis and genetic counseling. An epidemiologic study of MEDT and SEDT in a well-defined population of 453 921 persons in Denmark was performed. A population prevalence of 0.7 per 100000 inhabitants with SEDT and 4.0 per 100 000 inhabitants with MEDT was found. Distinguishing features between MEDT, SEDT and bilateral LPD based on radiologic findings in the hips, other joints, and spine were ascertained. Bilateral LPD is always asymmetric, exhibits patches of increased density in the epiphyses and often metaphyseal cyst-like changes. No spinal lesion or affection of other joints is present, and the acetabula are normal. In MEDT and SEDT the capital femoral epiphyses are symmetrically flattened, fragmented and uniformly slightly sclerotic. Generalised platyspondyly is a constant finding in SEDT.

scholarly journals Do Normal Radiographs Exclude Asphericity of the Femoral Head-Neck Junction?

2008 ◽  
Vol 467 (3) ◽  
pp. 651-659 ◽  
Author(s):  
Marcel Dudda ◽  
Christoph Albers ◽  
Tallal Charles Mamisch ◽  
Stefan Werlen ◽  
Martin Beck
Keyword(s):  
Femoral Head ◽  
Head Neck ◽  
Neck Junction

The modified Stulberg classification is a strong predictor of the radiological outcome 20 years after the diagnosis of Perthes’ disease

2021 ◽  
Vol 103-B (12) ◽  
pp. 1815-1820
Author(s):  
Stefan Huhnstock ◽  
Ola Wiig ◽  
Else Merckoll ◽  
Svein Svenningsen ◽  
Terje Terjesen
Keyword(s):  
Femoral Head ◽  
Skeletal Maturity ◽  
Strong Predictor ◽  
Perthes Disease ◽  
Radiological Outcome ◽  
Long Term Follow Up ◽  
The Mean ◽  
Stulberg Classification

Aims The aim of this study was to assess the prognostic value of the modified three-group Stulberg classification, which is based on the sphericity of the femoral head, in patients with Perthes’ disease. Methods A total of 88 patients were followed from the time of diagnosis until a mean follow-up of 21 years. Anteroposterior pelvic and frog-leg lateral radiographs were obtained at diagnosis and at follow-up of one, five, and 21 years. At the five- and 21-year follow-up, the femoral heads were classified using a modified three-group Stulberg classification (round, ovoid, or flat femoral head). Further radiological endpoints at long-term follow-up were osteoarthritis (OA) of the hip and the requirement for total hip arthroplasty (THA). Results There were 71 males (81%) and 17 females. A total of 13 patients had bilateral Perthes’ disease; thus 101 hips were analyzed. At five-year follow-up, 37 hips were round, 38 ovoid, and 26 flat. At that time, 66 hips (65%) were healed and 91 (90%) were skeletally immature. At long-term follow-up, when the mean age of the patients was 28 years (24 to 34), 20 hips had an unsatisfactory outcome (seven had OA and 13 had required THA). There was a strongly significant association between the modified Stulberg classification applied atfive-year follow-up and an unsatisfactory outcome at long-term follow-up (p < 0.001). Between the five- and 21-year follow-up, 67 hips (76%) stayed in their respective modified Stulberg group, indicating a strongly significant association between the Stulberg classifications at these follow-ups (p < 0.001). Conclusion The modified Stulberg classification is a strong predictor of long-term radiological outcome in patients with Perthes’ disease. It can be applied at the healing stage, which is usually reached five years after the diagnosis is made and before skeletal maturity. Cite this article: Bone Joint J 2021;103-B(12):1815–1820.

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