A cadaveric model for ligamentum teres function: a pilot study

Purpose

Despite the prevalence and clinical consequences of ligamentum teres pathology, its function is poorly understood. The purpose of this study was to help define the role the ligamentum teres may have in hip joint stabilization and determine whether a ball and string model could be used to describe the function of the ligamentum teres.

Methods

Eight embalmed cadavers were dissected to remove all soft tissue from around the hip, leaving only the ligamentum teres intact. Available hip abduction, adduction, medial rotation, and lateral rotation range of motion were measured for three repeated trials. The position of the ligamentum teres in relation to the femoral head was recorded at the endpoint position of these movements.

Results

An endpoint position as limited by the ligamentum teres for abduction, medial rotation, and lateral rotation was identified at a mean of 73°(SD 11°), 64°(SD 11°), and 58°(SD 10°), respectively. Hip adduction was limited by bony contact and therefore was not measured. The ligamentum teres wrapped around the femoral head to prevent inferior, posterior, and anterior subluxation with abduction, medial rotation, and lateral rotation, respectively. Repeated measures ANOVA indicated no significant difference in endpoint position based on trial number for the three movements (n.s.).

Conclusion

The ligamentum teres consistently tightened to limit hip abduction, medial rotation, and lateral rotation. These results support a ball and string model for the femoral head and ligamentum teres. This information could be important for those with hip instability and ligamentum teres pathology.     

Function of the ligamentum teres during multi-planar movement of the hip joint

Purpose

The purpose of this study was to describe the orientation of the ligamentum teres and quantify the limb position when the ligamentum teres reached its endpoint during a simulated squat position in human cadavers.

Methods

Dissection of eight (4 male; 4 female) cadavers resulted in the complete removal of all soft tissue attachment of the femur to the acetabulum, leaving only the ligamentum teres intact. The limb was then moved into combined flexion and abduction of the hip joint to simulate a deep squat position until a ligamentous endpoint of the ligamentum teres was achieved. The orientation of the ligamentum teres in relation to the femoral head was described and the position of the limb relative to the sagittal plane (flexion) and frontal plane (abduction) was quantified. The mean, standard deviation, 95 % confidence intervals, and standard error of the measurement were calculated for the observed angles.

Results

Multi-planar movement of flexion and abduction moved the ligamentum teres into an anterior/inferior position relative to the femoral head and prevented the femoral head from anterior/inferior subluxation. The ligamentum teres endpoint was obtained at a combined average position of 100.6° (range 94°–112°; SD 5.5º; 95 % CI 96º–105º) and 20.0° (range 12°–32°; SD 7.0º; 95 % CI 14º–26º) flexion and abduction angle.

Conclusions

The ligamentum teres formed a “sling-like” structure to support the femoral head inferiorly as the hip joint was moved into a combined position of flexion and abduction that resembled a squat position. The results help to define a possible role of the ligamentum teres in hip joint stability and possible mechanisms of injury.     

MR findings associated with positive distraction of the hip joint achieved by axial traction

Purpose

To determine which MR-arthrography findings are associated with positive hip joint distraction.

Materials and methods

One hundred patients with MR arthrography of the hip using axial traction were included. Traction was applied during the MR examination with an 8 kg (females) or 10 kg (males) water bag, attached to the ankle over a deflection pulley. Fifty patients showing joint space distraction were compared to an age- and gender-matched control group of 50 patients that did not show a joint distraction under axial traction. Two radiologists assessed the neck-shaft angle, lateral and anterior center-edge (CE) angles, CE angles in the transverse plane, extrusion index of the femoral head, acetabular depth, alpha angle, acetabular version, ligamentum teres, joint capsule and ligaments, iliopsoas tendon and the labrum.

Results

Mean joint space distraction in the study group was 0.9?±?0.6 mm. Patients with positive joint space distraction had significantly higher neck-shaft angles (control group 131.6?±?5.4°/study group 134.1?±?6.1°, p?<?0.05), smaller lateral CE angles (38.1?±?5.9°/34.6?±?7.2°, p?<?0.05), smaller overall transverse CE angles (161.4?±?9.9°/153.6?±?9.6°, p?<?0.001), smaller acetabular depth (4.1?±?2.4 mm/5.8?±?2.5 mm, p?<?0.01), higher alpha angles (53.5?±?7.8°/59.2?±?10.1°, p?<?0.01) and a thicker ligamentum teres (4.7?±?1.4 mm/5.4?±?1.8 mm, p?<?0.05). The other parameters revealed no significant differences. ICC values for interobserver agreement were 0.71–0.95 and kappa values 0.43–0.92.

Conclusion

Increased neck-shaft angles, small CE angles, small acetabular depth, higher alpha angles and a thick ligamentum teres are associated with positive joint distraction.

     

The gymnasts’ hip and groin: a magnetic resonance imaging study in asymptomatic elite athletes

Objective

Specific patterns of developmental adaptation of the proximal femur have been recognized in some sports. Gymnastics are characterized by repetitive axial loading and hip rotations in combination with extreme hip positions. It is unknown how and if these forces can affect an immature skeleton in the long term. We sought to evaluate this, by means of magnetic resonance imaging of the hip and groin of such elite asymptomatic athletes.

Materials and methods

We performed a case-control comparative MR imaging study of both hips and groin of 12 (7 male, 5 female) skeletally mature young (mean age 18.6 years) asymptomatic international level gymnasts with a minimum of 10 years’ training with age-matched non-athletes. At the time of recruitment, none of the athletes had a recorded musculoskeletal complaint or injury in the anatomical area around the hip.

Results

The study showed that elite gymnasts share four common morphological characteristics on MRI that deviate from normal and are considered to be the result of adaptational changes to the specific sport: high centre–column–diaphysis angle (coxa valga140° on average), ligamentum teres hypertrophy, friction of the iliotibial band with oedema surrounding the greater trochanter, and a high incidence (62.5 %) of radiological appearances of ischiofemoral impingement.

Conclusion

Our study showed that elite gymnasts share four common morphological characteristics on MRI that deviate from normal. These findings were in asymptomatic subjects; hence, radiologists and sports physicians should be aware of them in order to avoid unnecessary treatment.     

Clinical assessment of hip strength using a hand‐held dynamometer is reliable

Hip strength assessment plays an important role in the clinical examination of the hip and groin region. The primary aim of this study was to examine the absolute test–retest measurement variation concerning standardized strength assessments of hip abduction (ABD), adduction (ADD), external rotation (ER), internal rotation (IR), flexion (FLEX) and extension (EXT) using a hand‐held dynamometer. Nine subjects (five males, four females), physically active for at least 2.5 h a week, were included. Twelve standardized isometric strength tests were performed twice with a 1‐week interval in between by the same examiner. The test order was randomized to avoid systematic bias. Measurement variation between sessions was 3–12%. When the maximum value of four measurements was used, test–retest measurement variation was below 10% in 11 of the 12 individual hip strength tests and below 5% in five of the 12 tests. No systematic differences were present. Standardized strength assessment procedures of hip ABD, ER, IR, FLEX, with test–retest measurement variation below 5%, hip ADD below 6% and hip EXT below 8%, make it possible to determine even small changes in hip strength at the individual level.     

The diagnostic performance of radiography for detection of osteoarthritis-associated features compared with MRI in hip joints with chronic pain

Objective

To evaluate the diagnostic performance of radiography for the detection of MRI-detected osteoarthritis-associated features in various articular subregions of the hip joint.

Materials and methods

Forty-four patients with chronic hip pain (mean age, 63.3?±?9.5 years), who were part of the Hip Osteoarthritis MRI Scoring (HOAMS) cohort, underwent both weight-bearing anteroposterior pelvic radiography and 1.5 T MRI. The HOAMS study was a prospective observational study involving 52 subjects, conducted to develop a semiquantitative MRI scoring system for hip osteoarthritis features. In the present study, eight subjects were excluded because of a lack of radiographic assessment. On radiography, the presence of superior and medial joint space narrowing, superior and inferior acetabular/femoral osteophytes, acetabular subchondral cysts, and bone attrition of femoral head was noted. On MRI, cartilage, osteophytes, subchondral cysts, and bone attrition were evaluated in the corresponding locations. Diagnostic performance of radiography was compared with that of MRI, and the area under curve (AUC) was calculated for each pathological feature.

Results

Compared with MRI, radiography provided high specificity (0.76–0.90) but variable sensitivity (0.44–0.78) for diffuse cartilage damage (using JSN as an indirect marker), femoral osteophytes, acetabular subchondral cysts and bone attrition of the femoral head, and a low specificity (0.42 and 0.58) for acetabular osteophytes. The AUC of radiography for detecting overall diffuse cartilage damage, marginal osteophytes, subchondral cysts and bone attrition was 0.76, 0.78, 0.67, and 0.82, respectively.

Conclusions

Diagnostic performance of radiography is good for bone attrition, fair for marginal osteophytes and cartilage damage, but poor for subchondral cysts.     

Radiological findings for hip dysplasia at skeletal maturity. Validation of digital and manual measurement techniques

Objective

To report on intra-observer, inter-observer, and inter-method reliability and agreement for radiological measurements used in the diagnosis of hip dysplasia at skeletal maturity, as obtained by a manual and a digital measurement technique.

Materials and methods

Pelvic radiographs from 95 participants (56 females) in a follow-up hip study of 18- to 19-year-old patients were included. Eleven radiological measurements relevant for hip dysplasia (Sharp’s, Wiberg’s, and Ogata’s angles; acetabular roof angle of T?nnis; articulo-trochanteric distance; acetabular depth-width ratio; femoral head extrusion index; maximum teardrop width; and the joint space width in three different locations) were validated. Three observers measured the radiographs using both a digital measurement program and manually in AgfaWeb1000. Inter-method and inter- and intra-observer agreement were analyzed using the mean differences between the readings/readers, establishing the 95% limits of agreement. We also calculated the minimum detectable change and the intra-class correlation coefficient.

Results

Large variations among different radiological measurements were demonstrated. However, the variation was not related to the use of either the manual or digital measurement technique. For measurements with greater absolute values (Sharp’s angle, femoral head extrusion index, and acetabular depth-width ratio) the inter- and intra-observer and inter-method agreements were better as compared to measurements with lower absolute values (acetabular roof angle, teardrop and joint space width).

Conclusion

The inter- and intra-observer variation differs notably across different radiological measurements relevant for hip dysplasia at skeletal maturity, a fact that should be taken into account in clinical practice. The agreement between the manual and digital methods is good.     

Effects of the use of oral contraceptives on hip and knee kinematics in healthy women during anterior stair descent

Purpose

Our aim was to evaluate the effects of the use of oral contraceptives (OC) on the hip and knee kinematics of healthy women during anterior stair descent.

Methods

Forty volunteers aged from 18 to 26 years were divided into two groups: 1—Group of women who had used OC for at least 3 months prior to evaluation (n = 20) and 2—Group of women who did not use OC (n = 20). The knee flexion/extension and abduction/adduction, hip flexion/extension, abduction/adduction and medial/lateral rotation excursions (degrees) were calculated for the dominant (supporting) limb during anterior stair descent. T tests for independent samples were used to compare the kinematic differences between the groups (α = 0.05).

Results

No significant difference was verified between the groups regarding the maximum excursion of knee flexion (n.s.) and abduction (n.s.) or hip flexion (n.s.), adduction (n.s.) and medial rotation (n.s.). When considering the knee flexion at 50°, no significant difference was verified between the groups regarding the excursion of knee abduction (n.s.) or hip flexion (n.s.) adduction (n.s.) and medial/lateral rotation (n.s.).

Conclusion

These results suggest that the use of OC does not influence the hip and knee kinematics during anterior stair descent. Therefore, the role of this medication as a protective factor against anterior cruciate ligament injuries remains questionable.

Level of evidence

III.     

Femoral anteversion is correlated with acetabular version and coverage in Asian women with anterior and global deficient subgroups of hip dysplasia: a CT study

Objective

Morphological correlation between the acetabulum and femur at the hip joint is still controversial. We tested the hypothesis that femoral anteversion correlates with acetabular version and coverage in patients with developmental dysplasia of the hip (DDH).

Materials and methods

Using pelvic computed tomography (CT) images of 79 hips in 49 Asian women with DDH and 49 normal hips, we measured femoral anteversion, the axial and vertical acetabular version and the acetabular sector angle (ASA) to demarcate femoral head coverage. Depending on the location of the acetabular bone defect, dysplastic hips were divided into three subgroups: the anterior, global and posterior deficiency groups. We performed a comparative analysis between dysplastic and normal hips using the Wilcoxon rank sum test, and a relative analysis between femoral anteversion and acetabular measurements in dysplastic hips using Pearson’s correlation coefficient.

Results

The amount of femoral anteversion in dysplastic hips was greater and more variable than in normal hips (p?p?=?0.0277 respectively). Femoral anteversion in dysplastic hips correlated significantly with acetabular anteversion in the groups with anterior and global deficiency subgroups (p?p?Conclusions Our results showed significantly greater and more variable femoral anteversion in DDH, and a significant correlation between femoral anteversion and acetabular version and coverage in DDH with anterior and global acetabular bone deficiency.     

Femoroacetabular impingement in elite ice hockey players

Purpose

The purpose of this study is to evaluate the presence of clinical and radiological femoroacetabular impingement (FAI) in elite ice hockey players and compare it to a control group of non-athletes.

Methods

Forty participants (20 non-athletes and 20 elite ice hockey athletes) underwent an evaluation of their hip joint, including assessment of range of motion and special provocative impingement tests. Two musculoskeletal radiologists assessed MRIs completed on each participant for radiological findings associated with FAI, including alpha angle, acetabular version angle, acetabular depth, and/or a lateral centre edge angle, and findings of labral and cartilage degeneration. A comparative analysis of the clinical and radiological findings was subsequently completed.

Results

There was a significant difference in the radiological CAM impingement measured by mean alpha angle between both groups (non-athletes: 43.2 degrees, SD 9.7; and athletes: 54.2 degrees, SD 12 (p = 0.003)). There were no statistically significant differences between the groups upon evaluating PINCER impingement. There were no statistically significant differences in clinical examination findings between both groups.

Conclusion

MRI evidence suggests that CAM impingement is more common in the elite ice hockey athlete in comparison with non-athletes. However, as this is a pilot study examining findings in asymptomatic individuals, there is a need for a longitudinal prospective cohort study. In keeping with this, sufficient, long-term follow-up is required to assess at what point, if any, these subjects with radiological findings become symptomatic.

Level of evidence

Cross-sectional cohort study, Level III.     

Diagnostic accuracy of magnetic resonance imaging and magnetic resonance arthrography of the hip is dependent on specialist training of the radiologist

Objective

Significant differences between magnetic resonance imaging reports and intraoperative findings at the time of hip arthroscopy were documented in our practice. We sought to examine the accuracy of radiological reporting of hip pathology based on the training level of the reporting radiologist.

Materials and methods

A retrospective review of hip arthroscopies carried out between July 2008 and June 2009 identified 61 cases where original MRI scans had been reported by general community radiologists. These scans were then reviewed by musculoskeletal specialist radiologists who were blinded to both the original report and the surgical findings. Accuracy of both subsets of radiologists was compared to arthroscopic findings with regard to labral, acetabular, femoral and impingement lesions.

Results

Musculoskeletal radiologists performed better than community radiologists in terms of overall accuracy. Accuracy rates for MSK radiologists were 85, 79, 59, and 82% for labral, acetabular chondrosis, and femoral chondrosis and impingement lesions, respectively. Whereas accuracy rates for community radiologists were 70, 28, 52, and 59% (p values?=?0.08, <0.001, 0.59, <0.001). Accuracy was significantly improved for both groups of radiologists when MR arthrograms were reviewed rather than conventional MRIs.

Conclusions

This study establishes the relationship between accuracy of reporting and the training level of the performing radiologists.     

Arthroscopic debridement of the isolated Ligamentum Teres rupture

Purpose

Most tears of the Ligamentum Teres (LT) are diagnosed when treating other hip pathologies. The purpose of this study was to evaluate the outcome of arthroscopic surgery for a unique group of patients with symptomatic isolated Ligamentum Teres rupture of the hip.

Methods

The study included 29 patients who suffered from an isolated Ligamentum Teres rupture of the hip and were treated with an arthroscopic debridement from 2003 to 2008. Patients with femoroacetabular impingement or other hip pathologies except Ligamentum Teres tear were excluded. Clinical results were measured preoperatively and postoperatively with the modified Harris Hip Score (MHHS) and Non-Arthritic Hip Score (NAHS). The mean age was 25?years (SD?±?11) with a mean follow-up time of 2.5?years (SD?±?1.5).

Results

At the last follow-up, the mean MHHS improved from 70 to 86 [mean difference?=?16 (95% CI 4?C27)] and the mean NAHS improved from 64 to 86 [mean difference?=?22 (95% CI 10?C33)]. Five patients have had a second arthroscopic debridement due to symptomatic recurrent tears.

Conclusion

Arthroscopic debridement alone of the isolated Ligamentum Teres rupture has a short-term beneficial result in more than 80% of cases.     

Total hip prosthesis CT with single-energy projection-based metallic artifact reduction: impact on the visualization of specific periprosthetic soft tissue structures

Objectives

To compare the image quality of CT with iterative reconstruction alone and in association with projection-based single-energy metal artifact reduction (SEMAR) for the visualization of specific periarticular soft tissue structures in patients with hip prostheses.

Methods

CT studies from 48 consecutive patients with a hip prosthesis (24 unilateral and 24 bilateral) were retrospectively reconstructed using two different methods: iterative reconstruction (IR) alone and IR associated with SEMAR. The influence of metallic artifacts on the identification of various periarticular structures was evaluated subjectively by two readers. The image quality was compared in patients with unilateral and bilateral prostheses.

Results

Visualization of periprosthetic soft tissue was significantly improved by the SEMAR algorithm (p?<?0.0001). When SEMAR was associated with IR, the gluteus minimus and medius tendons, obturator internus muscle, prostate/uterus and bladder could be seen with medium or high confidence. There were no significant differences in image quality between patients with unilateral or bilateral prosthesis when SEMAR was used (p?>?0.2). This algorithm increased the detection of periarticular masses by 30 %.

Conclusion

SEMAR significantly improves the image quality of periarticular soft-tissue structures in patients with hip prostheses.     

Accuracy of CT-guided joint aspiration in patients with suspected infection status post-total hip arthroplasty

Objective

To determine the accuracy of guided computed tomography aspiration in the detection of septic hip prosthesis before surgery.

Materials and Methods

Sixty-three patients (35 women and 28 men; age range, 29?C86?years; mean age, 71?years) with clinically suspected septic hip prosthesis were prospectively studied with independent review board (IRB) approval. Volume and microbiological cultures of aspirated fluid and several computed tomography imaging findings such as periprosthetic fluid collections, prosthetic acetabular malposition, and heterotopic ossification were analyzed. All patients underwent revision surgery and infection was finally diagnosed in 33 patients.

Results

Statistical comparative analysis was performed comparing computed tomography aspiration and surgical findings (95% CI; level of significance at P?=?0.05 two-sided) with 70% sensitivity, 100% specificity, 84% accuracy, 100% positive predictive value, and 75% negative predictive value. Using Fisher??s exact test, the presence of periprosthetic fluid collections (P?=?0.001), prosthetic acetabular malposition (P?=?0.025) and aspirated fluid volume (P?=?0.009) were significantly higher in infected than in non-infected prostheses, whereas heterotopic ossification was not (P?=?0.429).

Conclusion

Computed tomography aspiration is accurate to preoperatively diagnose septic hip prosthesis on the basis of volume and bacterial cultures of aspirated joint fluid. Furthermore, imaging findings such as periprosthetic fluid collections and prosthetic acetabular malposition strongly suggest infected prosthesis.     

Patellofemoral kinematics during deep knee flexion after total knee replacement: a computational simulation

Purpose

Actions requiring deep knee flexion, such as kneeling and squatting, are challenging to perform after total knee replacement (TKR), though many manufactures emphasize that their knee prostheses could safely achieve high flexion. Little is known about the patellofemoral kinematics during deep flexion. This study aimed to track the movement of the patella during kneeling and squatting through dynamic computational simulation.

Methods

A validated knee model was used to analyse the patellar kinematics after TKR, including shifting, tilting and rotation. The data were captured from full extension to 135° of knee flexion. For kneeling, an anterior force of 500 N was applied perpendicularly on the tibial tubercle as the knee flexed from 90° to 135°. For squatting, a ground reaction force was applied through the tibia from full extension to 135° of flexion.

Results

This study found that patellar shifting and rotation in kneeling were similar to those while squatting. However, during kneeling, the patella had a greater medial tilt and showed signs of abrupt patellar tilt owning to an external force being concentrated on the tibial tubercle.

Conclusions

In terms of squatting and kneeling movements, the latter is a more strenuous action for the patellofemoral joint after TKR due to the high forces acting on the tibial tubercle. It is suggested that overweight patients or those requiring high flexion should try to avoid kneeling to reduce the risk of the polyethylene wear. Further modification of trochlear geometry may be required to accommodate abrupt changes in patellar tilting.

Level of evidence

II.     

Colour Doppler Ultrasound Assessment of the Normal Neonatal Hip

Objective

To determine the morphology and hemodynamic characteristics of the arterial vessels of the proximal femur according to specific anatomic regions in asymptomatic neonates in 2 pediatric-based health care institutions.

Methods

Forty-three neonates (29 female, 14 male; age range, 2 d–3 mo; median age, 3 d) were enrolled in the study. Thirty-two (37%) of 86 hips were classified as Graf type IIA joints (mean alpha angle, 56.0° ± 2.7°), and 54 (63%) were classified as type I joints (mean alpha angle, 65.0° ± 4.6°).

Results

Colour and spectral Doppler imaging identified vessels running along the acetabular labrum, epiphyseal vessels, and femoral neck. We showed 4 different patterns of vascularity of the hips: radial, parallel, mixed radial–parallel, and indeterminate, however, they were not related to the hip maturity (P = .3, coronal plane; P = .62, transverse plane) or to the amount of colour pixels identified in each region (P = .35). The mean number of pixels in the ligamentum teres region was significantly higher than that in other regions of interest (P = .03). Except for the acetabular labrum arteries, Doppler spectrum waveforms of proximal femur arteries presented with low resistivity. There was a tendency towards females' acetabular arteries presenting with lower peak systolic velocities than males' acetabular arteries (P = .06).

Conclusions

Colour Doppler spectrum waveforms and intensity of vascularity in normal neonatal hips differ according to the anatomic region under evaluation. This observation deserves further investigation on its role on the physiopathogenesis of neonatal hip disorders.     

MRI morphometric hip comparison analysis of anterior acetabular labral tears

Objective

Anterior (3 o’clock) acetabular labral tears (AALTs) have been reported to be associated with iliopsoas impingement (IPI). However, no study has examined the association between anatomical bony variables of the hip joint and AALTs. The purpose of this study was to evaluate the association between AALTs, femoroacetabular impingement (FAI) and other bony variables of the hip.

Material and methods

Seventy-six out of 274 hip MRI records met the inclusion criteria. Two independent blinded investigators evaluated the location of acetabular labral tears (ALTs), edema at the musculotendinous junction of the iliopsoas insertion, femoral neck anteversion angle, femoral neck shaft angle, acetabular anteversion angle, alpha angle, lateral central edge angle (LCEA), acetabular index, and acetabular depth. Comparison analyses between groups were performed.

Results

Twenty-two patients had no ALTs (controls), 19 patients had AALTs, and 35 patients had ALTs not isolated at the 3 o’clock position (25 with cam-bony deformities [FAI-cam] and 10 with pincer-bony deformities [FAI-pincer]). The alpha angle mean was significantly higher (p?<?0.001) in the FAI-cam group (62.7º, 95 % confidence interval [CI]: 56.2–69.2º) compared with the AALTs group (46.9º, 95 % CI: 40.1–53.7º). The LCEA mean was significantly higher (p?<?0.001) in FAI-pincer group (41.9º, 95 % CI: 39.3º–44.5º) compared to AALTs group (29.4º, 95 % CI: 24.2º–34.6º). There was no statistically significant difference in any of the bony variables between the controls and the AALTs group.

Conclusion

Our study demonstrated that AALTs are pathologically distinct and not associated with FAI or other bony abnormalities. This supports the previous studies, which proposed that AALTs are associated with IPI.     

The fate of the hip in spondylo-epi-metaphyseal dysplasia: clinical and radiological evaluation of adults with SEMD Handigodu type

Purpose

This study was undertaken to document the fate of the hip with reference to its structure and function in patients with spondylo-epi-metaphyseal dysplasia tarda Handigodu type (SEMD_HG).

Material and methods

Radiographs of 271 adult patients with SEMD_HG were studied to identify the pattern of long-term sequelae in the hips. Several measurements of the proximal femur and acetabulum were made to quantify morphological alterations in the hip. Fifty-four adult patients were examined and administered a questionnaire to evaluate the extent of disability attributable to the hips.

Results

Three patterns of changes in the hips were noted: 35% had acetabular protrusio, 33% had subluxation of the hip, and 32% had no protrusio or subluxation. Distinctly different anthropometric measurements and dimensional alterations around the hip were noted in these three patterns. Patients with protrusio were relatively tall while those with subluxation were the shortest. All the patients had developed degenerative arthritis of the hips by the fourth decade of life irrespective of the pattern of hip involvement. The reduction in the range of hip motion and fixed deformities were most severe in patients with protrusio. All the patients had significant disability and very low functional hip scores.

Conclusion

Degenerative arthritis of the hip develops in the majority of patients with SEMD_HG; the symptoms are severe enough to warrant reconstructive surgery by the fourth decade of life. Protrusio or subluxation develops in a third of the patients each; both these complications will influence the surgical approach if total hip arthroplasty is planned.