Proximal Femoral Geometry: A Radiological Assessment

doi:10.1016/j.arth.2005.11.003

The Journal of Arthroplasty

Volume 21, Issue 6, September 2006, Pages 897-898

https://doi.org/10.1016/j.arth.2005.11.003 Get rights and content

Abstract

We aimed to analyze radiographically the relationship between the tip of the greater trochanter and the center of the femoral head. One hundred fifty randomly selected radiographs of patients due to undergo total hip arthroplasty were analyzed for the relationship between the center of the femoral head and the tip of the greater trochanter. We found that the center of the femoral head was 9.5 ± 6 mm below (9 mm above to 24 mm below) the tip of the greater trochanter. Many techniques have been described to diminish the inadvertent limb lengthening during total hip arthroplasty. One of the commonly used methods has been alignment of the tip of the greater trochanter with the center of the femoral head. The aim of the article is to discourage the use of the tip of the greater trochanter as guide because it may lead to inadvertent limb lengthening.

Section snippets

Methods

One hundred fifty anterior-posterior radiographs of the pelvis of patients who were due to undergo THA were reviewed with standard magnification. The pathology in all the hips studied was osteoarthritis. Patients with inflammatory arthritides and osteoarthritis secondary to dysplasia were excluded, because they tend to have a wide degree of individual variations.

A line was placed along the long axis of the shaft of femur. This was done by plotting 3 pairs of points along the shaft of the femur.

Results

In our study, we found that the center of the femoral head was between 9 mm above the tip of the trochanter to 24 mm below the level of the trochanter.

We found that in 82% of cases (123 hips), the center of the femoral head lies below the level of the tip of the greater trochanter. In 4% (6 hips), the center was at level of the tip of the trochanter, and in 14% (21 hips), the center of the femoral head was above the level of the trochanter.

Discussion

Limb length discrepancy after THA remains a common cause of patient dissatisfaction. A review of the literature reveals 2 distinct types of limb lengthening. In the first scenario, the previously shortened limb has been corrected by the arthroplasty to a normal level and equal to the contralateral limb. In the second type, the limb was overcorrected and as a result was longer than the contralateral unaffected limb.

Our study shows that assessing the limb length by aligning the tip of the greater

References (5)

Anatomy of the femur, Gray's Anatomy online version
J.A. Williamson et al.
Limb length discrepancy and related problems following total hip replacement
Clin Orthop
(1978)

There are more references available in the full text version of this article.

Cited by (19)

Simple guidelines for evaluating intraoperative alignment after the reduction of intertrochanteric fractures
2021, Asian Journal of Surgery
The incidence of intertrochanteric femoral fractures has rapidly increased with the extended lifespan of the elderly population. Surgery enables early ambulation by achieving anatomic reduction and stable internal fixation. However, reduction usually involves postoperative evaluation. Here, we present reliable parameters obtained from analyses of three-dimensional computed tomography images from cadavers to serve as guidelines during the reduction of intertrochanteric fractures.
We included 184 three-dimensional modeling samples from cadavers placed in two standardized positions, similar to C-arm imaging. We recorded the level of the orthogonal line from the greater trochanter (GT) tip to the femoral head (GT orthogonal line [GTOL]) in the anteroposterior view and the line along the anterior femoral cortex passing through the femoral head (anterior cortical line) in the axial view. Correlations between these lines and angular alignments were statistically determined.
The GTOL passed above the femoral head center at mean 2.36 mm in all patients; 77.17% of such instances were in the upper second quadrant of the femoral head. The anterior cortical line passed under the femoral head center at mean 10.82 mm; 73.37% of such instances were in the inferior one-third of the femoral head. Consistent correlations were found between the GTOL and neck-shaft angle and between the anterior cortical line and anteversion.
The GTOL and anterior cortical line passed through a constant level of the femoral head in most samples and were correlated with angular alignments. The intraoperative use of these simple imaginary lines improves the intertrochanteric fracture reduction quality.
Reliability of relation between greater trochanter and center of rotation of femoral head in Indian population
2020, Journal of Clinical Orthopaedics and Trauma
Citation Excerpt :
There are few previous studies concerning this relationship in other populations which are summarized in Table 1. Our results are comparable to those of Dhinsa BS et al.,8 Memon AR et al.,10 Panichkul P et al.11 and Antapur P et al.12; those studies were based on the populations from United Kingdom, Ireland, and Thailand. However, the results are markedly different from those of Theivendran K et al.9 and Unnanuntana A et al.3 which studied populations from the United Kingdom and the USA, respectively.
Accurate limb length restoration forms an important aspect of reconstructive surgeries around the hip joint. Among the various intraoperative methods for accurate limb length restoration, the relation between the greater trochanter and the center of the femoral head has been conventionally used owing to its simplicity and replicability. The current study aims to study the normal relation between the greater trochanter and the center of rotation of the femoral head, its population-based variation and its gender-based and contralateral differences in the Indian population.
Standard anteroposterior radiographs of normal hip joints with the proximal femur, performed over a one year period were studied. A software-based analysis was conducted to measure the difference between the levels of the greater trochanteric tip and the center of the femoral head along the longitudinal axis of the femur. The measurements among the male and female cases and the contralateral sides were compared.
The greater trochanteric tip lies at a higher level than the center of rotation of the femoral head by a mean difference of 9.20 ± 5.30 mm. No significant differences were observed among male and female groups and between the contralateral hip joints. Intraobserver and Interobserver reliability were high.
The tip of the greater trochanter and the center of the femoral head do not lie at the same level. This differential relation should be considered during the reconstructive surgeries around the hip joint to prevent an inadvertent limb length discrepancy. Considering the wide interindividual variations, this difference cannot be generalized for all the patients and restoring it to the contralateral normal hip would be more appropriate.
Intraoperative assessment of reduction quality during nail fixation of intertrochanteric fractures
2020, Injury
Citation Excerpt :
Haidukewych reported that the relationship between the greater trochanter and femoral head can be used to assess the varus/valgus and that the greater trochanter horizontal line can achieve the most optimal result when crossing the center of the femoral head [21]. Antapur et al. argued against the use of the greater trochanter tip as a guide for restoration of the femoral head center [28]. Baumgaertner et al. evaluated reduction quality, including the alignment and displacement of main fragments, based on two postoperative radiographic criteria.
The quality of intertrochanteric fracture reduction has traditionally been evaluated using simple radiographs. However, subjective intraoperative evaluation and efforts to achieve a perfect reduction are essential for optimal outcomes. This study aimed to establish criteria for the intraoperative assessment of the quality of intertrochanteric fracture reduction and also analyzed postoperative outcomes in terms of reduction quality.
This study included 106 patients who received cephalo-medullary nailing for the treatment of intertrochanteric fractures between March 2012 and May 2016 and were followed-up for at least 1 year. An image intensifier was used intraoperatively to evaluate reduction quality by examining the restoration of anteromedial cortex continuity, and neck-shaft angle and anteversion. Based on the reduction quality, the patients were classified into optimal, acceptable, and unacceptable groups, with intervention provided for the unacceptable group. The need for revision surgery and the degree of blade sliding were assessed, and postoperative outcomes related to implant position were analyzed.
Over 50% of patients with Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) type 31A2 and A3 fractures were assigned to the unacceptable group after closed reduction (P = 0.006), and 60 cases required additional reduction. Approximately 40% of cases classified as clinically unacceptable required revision, and the rate of sliding was ≥2-fold higher in the unacceptable group than those in the optimal and acceptable groups (P = 0.015), with an average excessive sliding of 9.85 mm. Regarding implant position, cut-out or penetration were observed in cases with superiorly-located blades (P = 0.039).
Good outcomes cannot be achieved with traction alone for femoral intertrochanteric fractures. Active management is required because accurate anteromedial cortex reduction, and restoration of neck-shaft angle and anteversion are essential in femoral intertrochanteric fractures.
Effect of surgical and natural menopause on proximal femur morphometry in obese women
2020, Annals of Anatomy
Citation Excerpt :
The other factors that are investigated for femur are BMI, body composition, obesity, menopausal status, BMD, osteoporosis, genetics, variation, hip fractures, bilateral asymmetry, anthropometry, preoperative planning according to caput femoris morphology (Sugano et al., 1999), proximal hip replacement and total hip subluxation (Kirchengast et al., 2001; Petit et al., 2005). Many studies have been conducted that showed the relation between hip joint surgical techniques and proximal femur parameters (Antapur and Prakash, 2006; Byström et al., 2003). When previous researchers were evaluating the femur parameters, either they made use of radiography, computed tomography, or dual-energy X-ray absorptiometry (DXA) imaging techniques or they directly investigated the dry bone.
The purpose of this study is to determine whether there are differences in proximal femur parameters of women subjected to menopause surgically or naturally. In this study, 10 parameters belonging to proximal femur of a total of 60 women cases of whom 30 had a mean age of 55.53 ± 4.57 years; body mass index, 33.06 ± 4.21 kg/m²; menopause age, 48.10 ± 5.92; and menopause years, 7.50 ± 4.58; and who were subjected to natural menopause; and 30 women whose mean age was 56.10 ± 6.87 years; body mass index, 33.33 ± 3.76 kg/m²; menopause age, 48.00 ± 4.64 years and menopause year, 8.10 ± 7.29; who were subjected to surgical menopause, and who did not use hormone replacement, were examined by radiography. Their anthropometric measurements, body compositions, blood hormone analyses (FSH, LH, estradiol, progesterone) and bone mineral densities (femur neck, femur total, lumbar t-score) were evaluated. It was found that there was no difference between surgical and natural menopause with respect to proximal femur parameters (p > 0.05). It was also found that FSH levels were high in the surgical menopause group and there were significant differences between the groups (p < 0.040). No significant difference was found even though bone mineral density t-score tests were lower in the surgical menopause group (p > 0.05). It was found that the difference in low bone mineral density level and high FSH values in the surgical menopause group do not have a relationship with proximal femur morphometry. It was determined that even though the women did not have ovaries, there was no difference between surgical menopause women and natural menopause women with respect to proximal femur morphometry.
Femoral Head Size is Correlated With Head Position in Very Elderly Patients
2017, Journal of Arthroplasty
In cases of femoral neck fracture, it is often not possible to accurately determine the original position of the head center to assess appropriate restoration of leg length. The aim of this study was to determine the accuracy of predicting the position of the femoral head center based on new and established correlations between the femoral head diameter (FHD) and the distance between the lesser trochanter and the femoral head center (LT-FHC) in the very elderly (aged ≥80 years) as the mainly affected but yet underinvestigated group.
The FHD and the LT-FHC distance were determined in 148 subjects (104 males, 44 females); 90 aged ≥80 years and 58 aged <80 years. For each age and gender subgroup one specific (LT-FHC)/FHD ratio was determined. The accuracy of the new determined ratios and the established ratios by others were compared by recalculating the LT-FHC distance of each individual subject.
The FHD and the LT-FHC were significantly correlated, most strongly in elderly females (R = 0.554, P < .001). Using the new age- and gender-specific ratios, the LT-FHC distance could be predicted within 10 mm of the true value in 95% of the cases and in only 77% using previously reported formulas.
Age- and gender-specific formulas yield higher accuracy than generic formulas. The formulas presented in this study can offer a practical, easy to use instrument for orthopedic surgeons performing hip arthroplasty in very elderly patients in addition to classic techniques to prevent significant leg-length discrepancy.
The Femoral Head Center Shifts in a Mediocaudal Direction During Aging
2017, Journal of Arthroplasty
Citation Excerpt :
Third, the rule of thumb that the FHC is located at the level of tip of the GT does neither apply on the normal-aged THA population nor on the very elderly population and should, therefore, be seen as a common misconception. Although several authors reported this finding, the present study is the first assessing this relationship in 3 dimensions on a very elderly population [36,37,46,47]. As a consequence, none of the previous studies were able to reveal that in elderly females aged 80 years and older the FHC is on average 12.2 mm caudal to the tip of the GT, as reported in this study.
Accurate reconstruction of hip joint biomechanics is the key stone in total hip arthroplasty. Although proximal femur morphology is known to vary with both age and gender, few studies investigated this in the very elderly (ie, ≥80 years). The purpose of this study was to compare basic morphological parameters describing the position of the femoral head between very elderly and middle-aged subjects.
Computed tomographic scans of the femur of 90 very elderly (mean 84 years, range 80-105 years) and 58 middle-aged subjects (mean 52 years, range 20-79 years) were made. After 3-dimensional reconstruction, the neck-shaft angle, femoral neck anteversion angle, femoral head height, femoral neck length, and mediolateral offset (ML-offset) were determined.
The neck-shaft angle was on average 3.6° less in elderly males (125.9° ± 5.0°) than in middle-aged males (129.5° ± 5.1°) (P < .001). The femoral neck anteversion angle was not significantly different between both age and gender groups. The femoral head height was −12.3 mm in elderly females compared to −10.5 mm (Δ 17%) in elderly males (P = .284) and even −8.0 mm (Δ 54%) in middle-aged males. The ML-offset was 10% (4.1 mm) larger in elderly compared to middle-aged males (P < .001).
These findings suggest that the femoral neck and head shift in a relative varus position during aging. Femoral prostheses with increased ML-offset and a lower caput-collum-diaphyseal angle are needed to accommodate the morphology of the femur in the very elderly. Care must be taken not to lengthen the operated leg, particularly in very elderly females.

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Original ArticleProximal Femoral Geometry: A Radiological Assessment

Abstract

Section snippets

Methods

Results

Discussion

Anatomy of the femur, Gray's Anatomy online version

Limb length discrepancy and related problems following total hip replacement

Clin Orthop

Original Article
Proximal Femoral Geometry: A Radiological Assessment