Acetabular Volume Research Articles

A Gender-based Study on the Morphometry of Cotyloid Cavity of the Coxal Bone in South Indian Population

Abstract Background and Aim: The cotyloid cavity (acetabulum) is a cup-shaped hollow on the lateral aspect of the coxal bone. The head of the femur articulates with cotyloid cavity to form the hip joint. The cotyloid cavity varies in size, shape, and depth among individuals. Any deviation from the normal range of parameters of the acetabulum may result in arthrosis-related pathologies. Materials and Methods: The present study was conducted on 200 dry human hip bones. The bones were collected from the department of anatomy of a medical college in Mangalore. The following morphometrical parameters of the cotyloid cavity were measured: (a) transverse diameter of acetabulum, (b) acetabular height, (c) acetabular depth, (d) acetabular volume, (e) distance from the pubic tubercle to the anterior rim of the acetabulum, and (f) ratio between distance from the pubic tubercle to the anterior rim of the acetabulum and acetabular height. Range, mean, standard deviation, and standard error of mean were determined for each parameter. P value was also calculated. Gender-wise comparison of the results was done. Results: The independent t-test was done, and the P value was calculated for each parameter. All the parameters showed significant differences between the male and female hip bones. Conclusion: In this modern era, total and partial hip replacement surgeries are very commonly performed. Therefore, knowledge regarding the various morphometrical parameters of the cotyloid cavity may be of great help in the preoperative planning period. It would also be of great help in the fields of forensic anthropology, osteology, and anatomy.

Morphometrical parameters of acetabulum of hip bone - An osteological study

Background: Acetabulum is an approximately hemispherical cavity on the lateral aspect of the hip bone. Acetabulum is not always of the same shape, size, or depth. Any deviations of the parameters from normal range have strong correlation with the development of various kinds of pathologies. Aims and Objectives: Acetabulum is an approximately hemispherical cavity on the lateral aspect of the hip bone. Acetabulum is not always of the same shape, size or depth. Any deviations of the parameters from normal range have strong correlation with the development of various kinds of pathologies. Materials and Methods: This study was conducted in department of Anatomy, Yenepoya Medical College, Mangalore. Two hundred hip bones were included in the study. Various parameters of the acetabulum were measured. The morphometrical parameters measured were: (a) Transverse diameter of acetabulum, (b) acetabular height, (c) acetabular depth, (d) acetabular volume, (e) distance from pubic tubercle to anterior rim of acetabulum, (f) ratio between distance from pubic tubercle to anterior rim of acetabulum and acetabular height. Range, mean, standard deviation, and standard error of mean were determined for each parameter. P value was also calculated to compare the parameters side wise. Results: The independent T test was done and the P value was calculated for each parameter. Acetabular volume showed a significant difference between left- and right-sided bones. Most of the parameters showed highly significant difference between male and female hip bones in both right side and left side. Conclusion: As total and partial hip replacements are common surgeries performed these days, knowledge of the dimensions of acetabulum will assist prosthetists to construct suitable prosthesis for Indian population. It would be also useful in the fields of anatomy, osteology, and anthropology.

The significance of the Dega osteotomy.

Wiktor Dega has significantly impacted contemporary pediatric orthopedics by developing transiliac osteotomy - Dega's pelvic osteotomy. The global implementation of the surgery technique gained dynamism in the 2000s after being published by Ward and Grudziak. Since then, derivative operative techniques called Dega, Dega-like or Dega family osteotomies have been developed. We analyzed the original articles published by Dega between 1929 and 1974 concerning transiliac osteotomy technique development and articles about its derivatives. The epidemiological significance of developmental hip dysplasia focused Wiktor Dega's attention in the 1920s. At that time, he treated patients according to König's idea of acetabular roof plastic surgery. The osteotomy depth gradually increased, which allowed deeper graft placement to perform what we nowadays call acetabuloplasty. In 1958, Dega coined the name 'supraacetabular semicircular osteotomy'. It differed from the final concept of the transiliac osteotomy by not assuming the cut of the inner cortex of the iliac bone. The hinge for the acetabular rotation was located at the inner cortex's whole length, disallowing the excessive redirection. The final concept of osteotomy allows for simultaneous acetabuloplasty and redirection to change the shape, location and acetabular volume. Dega derivatives are Mubarak (San Diego) and high Dega osteotomies. Dega osteotomy and its derivates are routinely implemented to treat developmental hip dysplasia and spastic hip disorders. It might be considered an option in Legg-Calve-Perthes disease, congenital deficiencies, and flaccid hip displacement in neurological conditions.

Comparison of Acetabular Morphology Changes After Pediatric Pelvic Osteotomies Using Patient-Specific 3-D Models

Background: Surgical management to improve hip joint morphology in immature patients with acetabular dysplasia includes Pemberton, Dega, San Diego, and Salter acetabular osteotomies. This study evaluates acetabular morphology between these osteotomies using patient-specific 3-D printing technology. Methods: Preoperative computed tomography scans (CTs) from patients with acetabular dysplasia were rendered into 3-D printable formats. Quadruplicate pelvis models for each patient received Pemberton, Dega, San Diego, and Salter osteotomies. CTs were obtained of each model before and after osteotomy. Acetabular volume and regional coverage angles were computed and compared before and after each osteotomy. Results: Fourteen hips (14 patients) were included; 1 male, 13 female; age 5.4±1.3 years (3.9-7.5 years). Acetabular volume decreased following each osteotomy (Pemberton by 14%, Dega by 19%, San Diego by 19%, and Salter by 6%), with smaller volume reduction for Salter than the others (p<0.05). Volume change was similar between Pemberton, Dega, and San Diego (p=0.32). Pemberton increased coverage in Superior and Anterior regions, Dega increased coverage in Superior, Superior-Anterior, and Anterior regions, San Diego increased coverage in Posterior, Superior-Posterior, and Superior regions, and Salter increased coverage in Superior region (p<0.05). Conclusions: Acetabular volume changes found in this study support the convention that redirectional osteotomies such as Salter are more volume neutral than incomplete osteotomies such as Pemberton, Dega, and San Diego. However, even the Salter decreased acetabular volume. This study re-demonstrated that each osteotomy studied changes acetabular coverage in different regions. Based on this, a surgeon’s osteotomy decision should be based on the dysplastic acetabulum morphology.

Anthropometric three-dimensional computed tomography reconstruction measurements of the acetabulum in children/adolescents.

The key element for differentiation between normal anatomical variants and pathological deformities is the prior definition of normal ranges for anthropometric parameters of acetabulum according to each age group. Aim of the present study is to analyze the development of the acetabulum in children/adolescents by accurate anthropometric measurements using 3D-CT scans and determine the variations occurring depending on age, gender and/or side. This retrospective observational study included 85 patients (170 hips) under 15 years of age (0-15) undergoing 1.5mm CT scanning for non-hip related reasons. The measurements were performed by 2 board-certified orthopaedic surgeons. Each year of life represented an age group forming a total of 16 groups. Median number of patients per age group was 12 (range 4-16). The anthropometric parameters included acetabular volume, inclination, version, depth (coronal and axial), width (coronal and axial), Tönnis angle as well as anterior and posterior acetabular sector angles. Mean values, range, standard deviation, p-values, intra- and interrater reliability were calculated. All measurement values correlated significantly with age. Statistically, there was no side or gender related difference. Rapid growth phases were observed at the age of 11-12. The inter- and intrarater reliability was high (range ICC 0.8-0.99, Cronbach alpha 0.86-0.99, Bland-Altman good agreement). The present data provides age- and gender-related normative values as well as growth phases describing acetabular morphology. It should help paediatricians as well as paediatric and orthopaedic surgeons as a tool for early diagnosis of deformity and guidance for possible procedures.

Quantification of Volume Mismatch of Acetabulum and Femoral Head in Developmental Dysplasia of Hip.

The sustained subluxation or dislocation of the femoral head over time does not permit normal development of acetabulum and results in predictable pattern of acetabular growth disturbance that is termed hip dysplasia. The primary aim of this study is to analyze and quantify the volume mismatch between acetabulum and femoral head of affected side as compared to normal hip. A prospective observational study was conducted by including isolated untreated unilateral idiopathic developmental dysplasia of hip (DDH). After routine clinical and radiographic examination, computed tomography (CT) of both hips was done with pre-determined radiation dosage within safe limits for the pediatric age group in 18 patients of median age 2 years (range 1-5 years). A significant difference was noted between acetabular index (p<0.001), acetabular volume (p<0.001), femoral head volume (p<0.001), and acetabular anterior sectoral angle (p=0.002) of the affected and the normal hips. As compared to the normal side, the acetabulum is 2.6 times smaller than the normal side and femoral epiphysis volume by 3.8 times. A significant negative correlation (r=-0.66, p=0.04) was noted between posterior acetabular sectoral angle and acetabular volume of affected hip. CT is an important investigation in evaluation of late-presenting DDH. The absence of femoral head in its orthotopic location affects the volume of acetabulum as well as that of femoral head. The abnormality of the volume of acetabulum which is seen as related to the dysplasia should be studied and assessed in detail in a child of late-presenting DDH. This would guide us toward the coverage defect and type of osteotomy to be performed.

Acetabular volume and femoral coverage change following Dega-like osteotomy in treatment of developmental dysplasia of the hip.

Although Dega's acetabuloplasty has become a commonly used osteotomy, there is still an ongoing debate regarding its impact on the volume and depth of the acetabulum. The purpose of our study was to assess the postoperative images of the transverse acetabular plane and version obtained from developmental dysplasia of the hip (DDH) patients after a modified Dega osteotomy. We performed a retrospective study of the morphologic indices obtained from the pelvic X-rays and computer tomography (CT) scans of patients with DDH, who were operated in our institution between July 2005 and October 2013, using the modified Dega osteotomy. Preoperative and postoperative pelvic X-rays were used to measure the acetabular index and the acetabular (ACM) angle. The postoperative CT scans were used to measure the acetabular anteversion angle (AAA), acetabular depth and depth of acetabular coverage [total acetabular index (TAI)]. The contralateral unaffected hips served as control. The postoperative acetabular indices and ACMs showed a significant improvement, with near-normal values measured 1 year after the surgery. Comparing the CT scan parameters (AAA, TAI and the depth of acetabulum) showed that TAI and the depth of acetabulum were not significantly different between the groups (TAI: P = 0.423; depth of acetabulum: P = 0.132), whereas AAA comparison implied a slight advantage of the DDH hips (17.6° DDH vs. 13.3° contralateral, P = 0.001). On the basis of images set of acetabular morphometric parameters, our study substantiates previous reports on an increase of acetabular volume and a significant improvement of femoral head coverage for patients with DDH who underwent Dega acetabuloplasty. Level of evidence: Level III - retrospective comparative study.

A three-dimensional measurement method on MR arthrography of the hip to classify femoro-acetabular impingement

Purpose(1) To investigate correlations between different types of FAI and the ratio of acetabular volume (AV) to femoral head volume (FV) on MR arthrography. (2) To assess 2D/3D measurements in identifying different types of FAI by means of cut-off values of AV/FV ratio (AFR).Materials and methodsAlpha angle, cranial acetabular version, acetabular depth, lateral center edge angle, AV, and FV of 52 hip MR arthrography were measured. ANOVA test correlated different types of FAI with AFR. ROC curves classified FAI by cut-off values of AFR. Accuracy of 2D/3D measurements was calculated.ResultsANOVA test showed a significant difference of AFR (p value < 0.001) among the three types of FAI. The mean values of AFR were 0.64, 0.74, and 0.89 in cam, mixed, and pincer types, respectively. Cut-off values of AFR were 0.70 to distinguish cam types from mixed and pincer types, and 0.79 to distinguish pincer types from cam and mixed types. Cut-off values identified 100%, 73.9%, and 55.6% of pincer, cam, and mixed types. 2D and 3D classifications of FAI showed accuracy of 40.4% and 73.0%.Conclusions3D measurements were clearly more accurate than 2D measurements. Distinct cut-off values of AFR discriminated cam types from pincer types and identified pincer types in all cases. Cam and mixed types were not accurately recognized.

Volume-based dysplasia severity index with the spheric cup method in the evaluation of adult and adolescent acetabular dysplasia

Introduction / Aim: Defining and treating adult and adolescent acetabular dysplasia before arthrosis develops is one of the basic principles of hip-preserving surgery. During the evaluation of cases with asymptomatic or mild symptoms, the severity of the acetabular covering deficiency directs the treatment. We attempted to find answers to two questions with our study: 1) Are the values revealed by the described measurement technique sufficient to detect acetabular dysplasia? 2) Do the criteria calculated by the current technique correlate with the well-known radiological criteria for acetabular dysplasia?&#x0D; &#x0D; Material and Method: Eighteen hips of patients who had undergone periacetabular osteotomy evaluated by computed tomography (CT) between June 2009 and February 2019 were included in the study (Group 1, dysplasia group). Eighteen patients of similar age and sex, who had tomography examination from the pelvic region, except for orthopedic reasons, were identified between the same dates (Group 2, control group). In the tomography examinations of the patients, the entrance area of the acetabulum was determined using the multiplanar reformation (MPR) technique. Acetabulum volume and femoral head volume was calculated according to the spheric cup measurement method. Acetabular index (AI), extrusion index (EI), Sharp angle (SA), lateral center edge angle (LCEA), and anterior center edge angle (ACEA) values were calculated from direct graphy and CT scanograms of the patients. &#x0D; &#x0D; Findings / Results: In the comparative analysis between the groups, a significant difference was observed in terms of acetabular volume, VBADSI, AI, EI, LCEA, SA, and ACEA values (p &lt; 0.05). &#x0D; &#x0D; Conclusion: Acetabular volume measured using the spheric cup method and the VBADSI proved to be criteria that could contribute to the diagnosis of acetabular dysplasia. It would be appropriate to measure the described method with a larger series to reveal values peculiar to specific communities.

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

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. 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. 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. With sufficient acetabular coverage, a relative increase in femoral neck shaft angle within the physiologic range is associated with decreased hip osteoarthritis. 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.

Acetabular shape and orientation of the spastic hip in children with cerebral palsy.

To see if three-dimensional (3D) methods could bring new understanding to acetabular changes in shape and orientation in the spastic hip and in which direction(s) acetabular orientation might change, which is crucial for planning appropriate hip correction surgery. We performed a retrospective study of pelvic computed tomography (CT) examinations in 20 consecutive patients (10 females, 10 males). The mean age of patients was 12 years 9 months (SD 2y; range: 9-16y) at the time of the CT examination. The control group consisted of 18 consecutive pelvic CT examinations (36 acetabula) of deceased individuals (six females, 12 males) aged 4 to 17 years (mean age: 10y 6mo; SD 5y 2mo) whose whole-body CT scans were taken shortly after their death. We compared 3D CT reconstructions of 28 unstable and dislocated hips in children with bilateral cerebral palsy (Gross Motor Function Classification System levels IV and V) with the unaffected side and typically developing controls to assess spatial orientation (inclination, anteversion, and tilt), acetabular volume, and surface area. Additionally, we analysed the multiple factors that may lead to structural and spatial changes of the acetabulum. Patients with dislocated and spastic hips had significantly lower anteversion (-3.2° and -1.4° respectively, p<0.001), increased inclination (85.2° and 85.3° respectively, p<0.001), and decreased tilt (24.6° [p=0.014] and 20.7° [p=0.013] respectively) compared with typically developing individuals. Regarding acetabular volume and surface area, dislocated and unstable hips had significantly lower volume (17.6ml vs 31.5ml respectively, p<0.001) and surface area (28.9cm2 vs 36.2cm2 respectively, p<0.001) than unaffected hips. Among several factors, only Reimer's migration index had an influence on acetabular orientation (i.e. anteversion, p=0.01), volume (p<0.001), and surface (p=0.004). Acetabula in patients with spastic hip disease were severely retroverted with increased steepness; acetabular orientation was distorted superoposteriorly. In rare cases, acetabular orientation was distorted only superiorly or superoanteriorly. Acetabular orientation was distorted superoposteriorly in most patients with severe bilateral cerebral palsy. More pronounced acetabular changes were found in hips with a higher Reimer's migration index.

Comparison of 3 Pediatric Pelvic Osteotomies for Acetabular Dysplasia Using Patient-specific 3D-printed Models.

Children with developmental dysplasia of the hip may require a pelvic osteotomy to treat acetabular dysplasia. Three osteotomies are commonly performed in these patients (Pemberton, Dega, and San Diego), though comparative studies of each are limited. The purpose of this study was to compare changes in acetabular morphology (acetabular version, volume, and octant coverage angles) created by these 3 osteotomies using matched patient-specific 3D-printed pelvic models. Fourteen patients with developmental dysplasia of the hip and preoperative computed tomography (CT) imaging were retrospectively included. For each patient CT, bone and cartilage tissues were independently segmented, and 3 identical pelvises were 3D-printed using a dual material printer. Bone was printed with rigid material and cartilage with flexible material to simulate the flexibility of the triradiate cartilage and pubic symphysis. Pemberton, Dega, and San Diego acetabular osteotomies were performed on the triplicate set of 3D prints. Acetabular version, volume, and octant coverage angles (posterior, superior-posterior, superior, superior-anterior, and anterior) were determined before and after each mock surgery by morphologic assessment using preoperative and postoperative CT images. San Diego osteotomy yielded a small increase (+3.34±1.71 degrees) in version, compared with decreases with Pemberton (-5.47±1.54 degrees) and Dega (-8.57±1.21 degrees, P<0.05). Acetabular volume decreased similarly for Pemberton (-13.36%±2.88%), Dega (-19.21%±2.73%), and San Diego (-19.29%±2.44%; P=0.215) osteotomies. San Diego osteotomy tended to have a larger postoperative increase in the posterior regions, and the Dega and Pemberton osteotomies tended to have larger postoperative increases in the anterior coverage regions. Quantifiable differences were identified in acetabular octant coverage angles and version between the 3 pelvic osteotomies. San Diego osteotomy increased acetabular coverage posteriorly resulting in acetabular anteversion, whereas Pemberton and Dega had greater superior-anterior coverage resulting in relative acetabular retroversion. This study is the first known to utilize 3D-printed models for comparison of surgical approaches in pediatric pelvic osteotomies.

Editorial review: Equalisation of leg lengths in total hip arthroplasty for patients with Crowe type-IV developmental dysplasia of the hip

Reconstruction of the dysplastic hip presents many well documented challenges. On the pelvic side a pseudoacetabulum may obscure normal landmarks. Once the true acetabulum is identi ed, the acetabular component may be placed in soft, previously unloaded bone which is often retroverted and simultaneously superiorly deficient, leading to compromised component-host bone contact and concerns regarding primary stability. Excessive medialisation or structural augmentation may therefore be required to achieve adequate coverage and stability. Reduced acetabular volume often necessitates the use of a small acetabular component necessitating the use of small bearing sizes.

Study of Sensor Deflection in Hip Simulator : Numerical and Experimental Method

A lot of Hip Joint Simulator have been made nowadays, most of them use different structure and method. This research reports a pin-on-ring tribometer design that is used to became hip joint simulator based on the movement of the salat (salat gait). Modified femoral head and acetabular cup holder are performed, to design a reciprocating motion for simulation of artificial hip movement. An interesting finding from this study is a new linked-bar mechanism that leads to the ability to move femoral head against the acetabular cup and measure wear volume of an THR patients during normal salat gait. The designed motion angle is 121.5° in the flexion direction and 15.5° in the direction of abduction. Linked bar for sensor dial indicator have enough adjustment, but there is still a movement that is not rigid upon running hip joint process simulator. This research concentrates on the bar is already linked in accordance or not when compared with the data in the simulate on a computer. Estimation error and deviations that occur between numerical and experimental is going forward to improve hip joint simulator Undip to be more precise and relevant research to use THR Undip.

Both Decreased and Increased Relative Acetabular Volume Are Associated with Increased Hip Arthritis in an Osteological Review of 1090 Hips

Both Decreased and Increased Relative Acetabular Volume Are Associated with Increased Hip Arthritis in an Osteological Review of 1090 Hips

Evaluation of late redislocation in patients who underwent open reduction and pelvic osteotomy as treament for developmental dysplasia of the hip.

The goal in the treatment of developmental dysplasia of the hip (DDH) is to achieve a stable and concentric reduction and to create a congruent relationship between the femoral head and the acetabulum. This study discusses the causes of loss of reduction in DDH patients who had a concentrically reduced hip at the time of removal of the hip spica cast and cessation of brace use and who later appeared with hip redislocation after mobilisation and ambulation. In addition, the possible interventions in such cases are also discussed. A retrospective evaluation was made of 13 patients diagnosed with DDH who developed redislocation following primary surgery. 6 of them had undergone the 1st surgery in our department between 2008 and 2016 and 7 had udergone surgery in another centre. For comparison reasons a 2nd group was formed of 13 demographically and clinically matched patients who had no loss of reduction. The groups were compared in terms of acetabular index, pelvic length, pelvic width, abduction degree of plaster, ossifying nucleus diameter, acetabular depth, and acetabular volume parameters. The average age of the patients was 23 months at initial surgery and 29 months at the time of revision surgery. No significant difference was found between the groups in terms of acetabular inclination angle, ossifying nucleus diameter, pelvic size, pelvic width, centre edge angle, acetabular volume, and depth. Contracted inferomedial capsule was found in 1 patient who underwent revision surgery and intact transverse acetabular ligament was seen in 1 patient. The loss of reduction in the remaining 11 patients was associated with high total anteversion of the femoral head and acetabulum. Correction of increased combined anteversion by femoral osteotomy can create a safe zone in terms of redislocation and can significantly contribute to the stability provided by capsulorrhaphy and pelvic osteotomy.

Decreased and increased relative acetabular volume predict the development of osteoarthritis of the hip

Recently, there has been considerable interest in quantifying the associations between bony abnormalities around and in the hip joint and osteoarthritis (OA). Our aim was to investigate the relationships between acetabular undercoverage, acetabular overcoverage, and femoroacetabular impingement (FAI) with OA of the hip, which currently remain controversial. A total of 545 cadaveric skeletons (1090 hips) from the Hamann-Todd osteological collection were obtained. Femoral head volume (FHV), acetabular volume (AV), the FHV/AV ratio, acetabular version, alpha angle and anterior femoral neck offset (AFNO) were measured. A validated grading system was used to quantify OA of the hip as minimal, moderate, or severe. Multiple linear and multinomial logistic regression were used to determine the factors that correlated independently with the FHV, AV, and the FHV/AV ratio. Female cadavers had smaller FHVs (standardised beta -0.382, p < 0.001), and AVs (standardised beta -0.351, p < 0.001), compared with male patients, although the FHV/AV ratio was unchanged. Every 1° increase in alpha angle increased the probability of having moderate OA of the hip compared with minimal OA by 7.1%. Every 1 mm decrease in AFNO increased the probability of having severe or moderate OA of the hip, compared with minimal OA, by 11% and 9%, respectively. The relative risk ratios of having severe OA of the hip compared with minimal OA were 7.2 and 3.3 times greater for acetabular undercoverage and overcoverage, respectively, relative to normal acetabular cover. Acetabular undercoverage and overcoverage were independent predictors of increased OA of the hip. The alpha angle and AFNO had modest effects, supporting the hypothesis that bony abnormalities both in acetabular dysplasia and FAI are associated with severe OA. Cite this article: Bone Joint J 2017;99-B:432-9.

Does Orientation of the Femoral Head Affect Acetabular Development? An Experimental Study in Lamb

Derotational osteotomy of the proximal femur has proved to be effective in the treatment of residual acetabular dysplasia. However, the reason why this osteotomy is effective remains debatable. The purpose of this study is to investigate if an alteration of femoral head orientation affects acetabular growth. A proximal femoral osteotomy was performed in 21 lambs aged 3 months: 5 varus osteotomies (110 degrees), 4 valgus osteotomies (150 degrees), and 12 derotation osteotomies. Results were compared with a control group (5 animals). Osteotomy was fixed with a screw-plate device. Version was controlled intraoperatively with K-wires. Animals were killed 3 months after surgical procedure. A morphometric study of both proximal femur and acetabulum was performed, including deepness, volume and diameters of the acetabulum, neck-shaft angle and femoral version. The average neck-shaft angle for the normal, anteversion, and retroversion groups was 129 degrees, whereas it was 110 degrees for the varus group and 149 degrees for the valgus group. The average femoral version for the normal, valgus, and varus groups was 21 degrees of anteversion, whereas it was 38 degrees of anteversion for the so-called anteversion group and 17 degrees of retroversion for the retroversion group. Nor the neck-shaft angle, nor the femoral version correlated with the acetabular anteroposterior diameter (P=0.698, 0.6, respectively), the acetabular inferosuperior diameter (P=0.083, 0.451, respectively) or the acetabular deepness (P=0.14, 0.371, respectively). The neck-shaft angle correlated significantly with acetabular volume (P=0.023), so that the lower the neck-shaft angle, the higher the acetabular volume (r=-0.453). The femoral version did not correlated with acetabular volume (P=0.381). Decreasing the neck-shaft angle provokes an increase in acetabular volume, whereas changes in femoral version do not affect the acetabular growth. Extra-articular osteotomies that alter femoral orientation affect intra-articular gross morphology. Level II-therapeutic study.

Hip Dysplasia Is More Severe in Charcot-Marie-Tooth Disease Than in Developmental Dysplasia of the Hip

Patients with Charcot-Marie-Tooth disease may develop hip dysplasia. Hip geometry in these patients has not been well described in the literature. We compared the hip morphometry in Charcot-Marie-Tooth hip dysplasia (CMTHD) and developmental dysplasia of the hip (DDH) in terms of extent of (1) acetabular dysplasia and subluxation, (2) acetabular anteversion and osseous support, (3) coxa valga and femoral version, and (4) osteoarthritis. Fourteen patients with CMTHD (19 hips; mean age, 23 years) presenting for periacetabular osteotomy were matched to 45 patients with DDH (45 hips; mean age, 21 years) based on age, sex, and BMI. We assessed acetabular dysplasia and subluxation using lateral center-edge angle (LCEA), anterior center-edge angle (ACEA), and acetabular roof angle of Tönnis (TA) on plain pelvic radiographs and acetabular volume, area of femoral head covered by acetabulum, and percentage of femoral head covered by acetabulum on three-dimensional CT reconstruction models. Acetabular version and bony support, femoral version, and neck-shaft angle were measured on two-dimensional axial CT scans. Hip osteoarthritis was graded radiographically according to Tönnis criteria. Acetabular dysplasia was more severe in CMTHD, as measured by smaller LCEA (p < 0.001), ACEA (p < 0.001), and acetabular volume (p = 0.0178) and larger TA (p = 0.025). Hip subluxation was more pronounced in CMTHD, as demonstrated by lower area of femoral head covered by acetabulum (p = 0.034) and percentage of femoral head covered by acetabulum (p = 0.007). CMTHD was associated with higher acetabular anteversion (p < 0.001), lower anterior (p < 0.001) and posterior (p = 0.072) osseous support, and more severe coxa valga (p < 0.001). More (p = 0.006) arthritic hips were found in CMTHD. The extent of acetabular dysplasia, hip subluxation, acetabular anteversion, coxa valga, and hip osteoarthritis was more severe in CMTHD. These findings are important in choosing the appropriate surgical strategy for patients affected by CMTHD.

Cyst Volume in the Acetabulum and Femoral Head Decreases after Periacetabular Osteotomy

In a series of 26 consecutive patients scheduled for periacetabular osteotomy (PAO), we examined how many had acetabular or femoral head cysts, investigated whether the volume of the cysts changed after PAO, calculated the precision of the method applied and scored their hip symptoms. Magnetic resonance imaging (MRI) was performed before PAO and at 1 and 2½ years post-operatively. The number of cysts was noted and the total cyst volume in each patient was estimated with a design-based stereological method and the precision of the method was calculated.The patients filled out The Hip disability and Osteoarthritis Outcome Score (HOOS) four years after PAO. Preoperatively, 12 patients had acetabular or femoral head cysts (22 cysts), 1 year postoperative, 15 patients had cysts (23 cysts) and 2½ years postoperative, 15 patients had cysts (18 cysts). Mean total acetabular cyst volume per patient decreased significantly from 1 year (1.96 cm³, SD 3.97) to 2½ years (0.96 cm³, SD 1.70) after PAO (p= 0.04). The Limits Of Agreement for measurement of cyst volume was ± 1.73 cm³. The mean subscore for Pain was 75, Symptoms 75, ADL 83, Sport/recreation 63 and Quality Of Life 62. The number of patients having cysts did not change notably after PAO. But the mean total cyst volume/patient decreased significantly between 1 and 2½ years after PAO. The PAO patients rated their hip comparable to the scores for patients six months after total hip replacement.