Mean Center-edge Angle Research Articles

Low osteotomy cut of Dega procedure for older children with developmental dysplasia of the hip.

The effect on acetabular management in developmental dysplasia of the hip (DDH) patients aged 7 or older with modified low Dega osteotomy procedure was evaluated. Patients between 7 and 14 years old were managed with modified low Dega osteotomy and open reduction and concomitant procedures to evaluate whether low level osteotomy improved the clinical and radiologic outcomes after treatment. Clinical status was assessed using the modified McKay's criteria; radiologic evaluations were assessed for the modified Severin classification, the mean acetabular index (AI), Sharp angle and center-edge (CE) angle. And occurrence of triradiate cartilage injury and complications was recorded. Forty-two DDH patients (57 hips) between 7 and 14 years old were managed with modified low Dega osteotomy. The results demonstrated the latest follow-up 43 hips (75.4%) were rated excellent and 10 hips (17.5%) rated good according to the modified McKay criteria and 41 hips (71.9%) were rated excellent and 11 hips (19.3%) rated good according to Modified Severin classification, respectively. The mean Hip Score improved from 69.53 ± 7.14 before the operation to 93.17 ± 8.43 at the final follow-up. The mean AI changed from 31.9° to 20.2°, mean Sharp angle decreased from 59.3° to 38.8° and mean CE angle increased from -10.9° to 35.2°, preoperatively and at latest follow-up, respectively. The modified low Dega osteotomy combined with open reduction and concomitant procedures were found to be adequate in improving instant and sustained clinical and radiographic outcomes for the late detected pediatric walking DDH patients.

THIRTY-YEAR FOLLOW-UP STUDY OF ROTATIONAL ACETABULAR OSTEOTOMY

Satisfactory intermediate and long-term results of rotational acetabular osteotomy (RAO) for the treatment of early osteoarthritis secondary to developmental dysplasia of the hip have been reported. The purpose of this study is to examine the 30-year results of RAO.Between 1987 and 1994, we treated 49 patients (55 hips) with RAO for diagnosis of pre- OA or early-stage OA. Of those patients, 35 patients (43 hips) were available at a minimum of 28 years. The follow-up rate was 78.2% and the mean follow-up was 30.5 years. The mean age at the time of surgery was 34 years. Clinical evaluation was performed with the Merle d'Aubigne and Postel rating scale, and radiographic analyses included measurements of the center-edge angle, acetabular roof angle, and head lateralization index on preoperative, postoperative AP radiographs of the pelvis. Postoperative joint congruency was classified into four grades. The radiographic evidence of progression of OA was defined as the minimum joint space less than 2.5mm.The mean preoperative clinical score was 14.0, which improved to a mean of 15.3 at the time of the latest follow-up. The mean center-edge angle improved from 0.6° preoperatively to 34° postoperatively, the mean acetabular roof angle improved from 28.4°preoperatively to 1.0°postoperatively, the mean head lateralization index improved from 0.642 preoperatively to 0.59 postoperatively. Postoperative joint congruency was excellent in 11 hips, good in 29 hips, and fair in 3 hips. Nineteen patients (20 hips) had radiographic OA progression, and 10 patients (11 hips) were converted to THA. Kaplan-Meier survivorship analysis, with radiographic OA progression as the end point, predicted survival of 75.6% at 20 years and 48.8% at 30 years, and with THA conversion as the end point, 90.2% at 20 years and 71.2% at 30 years.The RAO is an effective surgical procedure for symptomatic dysplastic hips of pre- and early-stage OA and could change the natural history of the dysplastic hip.

The natural history of acetabular dysplasia and later total hip arthroplasty in late-detected DDH: 48 patients with closed reduction followed to a mean age of 62 years.

The long-term prognosis of acetabular dysplasia without subluxation in developmental dislocation of the hip (DDH) is uncertain. The aim of this study was to assess the consequence of having acetabular dysplasia at skeletal maturity on the need for having a total hip arthroplasty (THA) up to the age of 60 years. Inclusion criteria were age at diagnosis 0.5-3.0 years, initial treatment with skin traction to obtain closed reduction during 1958-1962, and no acetabular procedures to improve femoral head coverage. 48 patients (57 hips) met these criteria, 41 girls and 7 boys. Hip dysplasia was defined as a center-edge (CE) angle at skeletal maturity of 10-19°, and hips with CE angles in the range 20-25° were termed borderline dysplastic. At skeletal maturity, 18 hips had acetabular dysplasia with a mean CE angle of 15.8° (10-19), whereas 19 hips were borderline with CE angles 20-25°, and 20 hips were normal (CE angles ≥ 26°). During the follow-up period 16 hips had undergone THA, 11 of 18 hips with dysplasia, 4 of 19 with borderline dysplasia, and 1 of 20 hips without dysplasia (p < 0.001). Hip survival in the 18 dysplastic hips, with THA as the endpoint, was 100% up to patient age 40 years; thereafter survival fell to 83% at 50 years and 39% at 60 years. There was no significant correlation between CE angle at skeletal maturity and age at THA (p = 0.2). The mean age at the last follow-up in patients without THA was 62 years (60-64). Acetabular dysplasia without subluxation was a risk factor for THA, but less than one-fifth of the hips had undergone THA up to patient age 50 years.

1034 Radiological Outcomes Following Surgery for Developmental Dysplasia of the Hip

Abstract Aim Developmental dysplasia of the hip (DDH) is a condition affecting newborns, in which abnormal acetabulum development can result in femoral head subluxation or dislocation. This study aims to retrospectively evaluate radiological outcomes of patients with DDH, treated by either closed reduction, open reduction, or open reduction with osteotomy. Method This study included 59 hips of 54 patients with a median age of 19.6 months at the time of surgery. Radiographs were assessed for the International Hip Dysplasia Institute (IHDI) grade of dislocation, acetabular index (AI), centre-edge angle (CEA), Severin classification and avascular necrosis (AVN). Results Median duration of follow up between primary operation and latest available radiograph was 4.9 years. Pre-operatively, 41 hips were IHDI Grade IV, 16 hips were Grade III and two hips were Grade II. Mean pre-operative AI was 37.9°, which decreased to 22.7° at the latest follow up. Mean CEA was 22.9°. 25 hips were found to be Severin class I, eight hips were class II and three hips were class III. Four hips developed Group II AVN and one hip developed Group III. Nine hips required further surgery. Conclusions The study found overall favourable radiological outcomes of treatment of DDH, with minimal differences between each operation. Longer follow up is needed to evaluate time-dependent outcomes such as Severin class and AVN. A patient-reported outcome questionnaire is necessary to provide information on the correlation of radiological outcomes and physical function.

Incidence of Acetabular Dysplasia in Asymptomatic Sudanese Adults

Objectives: The overall aim of this study is to evaluate the incidence of acetabular dysplasia in asymptomatic Sudanese adults. Methods: This is a cross-sectional population-based study, which includes radiographic examination of the Hip. A total of 240 hips are studied in scout view which is routinely done in patients undergoing CT KUB. The morphology of acetabulum is assessed by measuring the center edge angle (CEA), acetabular angle, acetabular depth to width ratio. Results: The study shows that the mean center edge angle is 36.07° (SD±5.74°), 36.01° (SD ±3.37°) for the Rt and Lt hips respectively. Mean acetabular angle is 37.5° (SD±3.7°) for the Rt and 36.9° (SD±3.9°) for the Lt hip, mean depth to width ratio is 0.3 (SD±0.03) and .29 (SD±.03) for the both hips respectively. The CEA is dysplastic in 1.7%, the acetabular depth/width ratio in 19.2% and the acetabular angle in 0.8% of the hips. The study shows statistical significant relationship between male gender and abnormal acetabular angle. Also, there is statistical significant relationship between left side and center-edge angle dysplasia. Conclusions: the incidence of hip dysplasia in Sudanese population is found to be higher when compared to South Asian and Indian population and lower than Sami and other Asian population.

Treatment of Severe Pincer-Type Femoroacetabular Impingement With Arthroscopic Significant Acetabular Rim Correction and Circumferential Labral Reconstruction Improves Patient-Reported Outcome Measures

To validate an arthroscopic approach for performing significant acetabular rim correction and circumferential labral reconstruction required to treat severe pincer-type femoroacetabular impingement. Using a minimum of 2-year follow-up, data from 48 hips, including 47 patients (11 male, 36 female; mean age of 42 years) having undergone significant arthroscopic acetabuloplasty for severe pincer impingement (center edge angle >45°) with concomitant circumferential allograft labral reconstruction were analyzed to determine improvements in patient-reported outcomes and degree of radiographic correction. Findings demonstrated a 98% success rate, including substantial improvements on all radiographic measurements and patient-reported outcomes. Minimal clinically important differences were met with extremely strong measures of effect. The mean center edge angle improved from 49° to 36° (MΔ= 13.96, P ≤ .001, standard deviation [SD]= 55.97, confidence interval [CI] 12.17- 15.62, d= 2.33) and the mean Tönnis angle improved from -6° to 0° (MΔ= 6.2, P ≤ .001, SD= 2.76 CI -7.1 to -5.39, d= 2.29). Modified Hip Harris Scores improved by a mean of 34.45 points (P ≤ .001, SD= 20.64, 95% CI 28.45-40.44, d= 1.66). Lower extremity functional scale scores improved by a mean of 27.35 points (P ≤ .001, SD= 18.37, 95% CI 22.02-32.69, d=1.48). No complications were reported. One case converted to a total hip arthroplasty (2%). Findings validated that the significant acetabular rim correction required to treat severe pincer morphology is safe and feasible via an arthroscopic approach. This, in addition to concomitant circumferential allograft labral reconstruction, resulted in improvement in patient-reported outcomes and radiographic measurements. Level IV, therapeutic case-series.

The effectiveness of peripheral compartment first access and periportal capsulotomy technique for arthroscopic management of femoroacetabular impingement: A prospective case series.

The aim of this study was to evaluate the functional results of hip arthroscopy for femoroacetabular impingement (FAI) performed via the periportal capsulotomy technique combined with capsular thinning and peripheral compartment first access. This prospective study included 34 patients (20 female, 14 male; mean age = 32.3 ± 12.5 years) treated for combined type FAI and labral tears between January 2016 and January 2018. In radiographic evaluation, center-edge angle (CEA) and alpha angle were measured preoperatively and postoperatively. Patients' functional status was assessed at 3, 6, 12, and 24 months using the modified Harris Hip Score (mHHS), Hip Disability and Osteoarthritis Outcome Score - Activities of Daily Living (HOOS-ADL), and Hip Disability and Osteoarthritis Outcome Score - Sports-Specific Subscale (HOOS-SSS), and visual analog scale (VAS). The mean alpha angle decreased from 55.5°±2.9° preoperatively to 48.3° ± 2.6° postoperatively. The mean CEA decreased from 39.2° ± 3.0° preoperatively to 32.9° ± 2.6° postoperatively. The mean duration of surgery was 96.7 ± 21.1 minutes; the mean traction time was 45.5 ± 14.6 minutes. The mean mHHS at the 3rd , 6th, 12th, and 24th months showed a statistically significant increase compared to the preoperative value (P < 0.05). The mean HOOS-ADL and HOOS-SSS at the postoperative 3rd, 6th, and 12th months demonstrated a statistically significant increase compared to the preoperative values (P < 0.05). The same scores measured at the 24th month, however, did not demonstrate a significant increase. The mean VAS scores at the 3rd and 6th months postoperative illustrated a significant decrease compared to the preoperative values (P < 0.05) whereas this significant decrease was not observed at the 12th and 24th months. The combined technique of periportal capsulotomy and capsular thinning used in this study seems to be a reliable surgical method with favorable functional results, a low complication rate, and a low risk of hip instability. Level IV, Therapeutic Study.

Can we still use X-rays to predict contralateral slip in primary unilateral slipped capital femoral epiphysis?

The objective of this study was to assess subsequent contralateral slip (SCS) in the unaffected hip in patients with primary unilateral slipped capital femoral epiphysis (SCFE) using three radiographic parameters: posterior sloping angle (PSA), center-edge angle (CEA) and triradiate cartilage (TC) appearance. A total of 152 patients admitted to two pediatric units between 2001 and 2015 were divided into three groups: A - underwent prophylactic fixation of the unaffected hip at the time of index surgery- high clinical risk of SCS; B - no clinical risk factors but SCS occurred; C - no issues regarding the contralateral hip during follow-up. The mean PSA for groups A, B and C were 22°(6-49), 17°(9-24) and 13°(0-27), respectively. PSA was significantly higher in Group A than in Group C ( P < 0.0001). The differences in PSA between groups A and B, but also B and C were insignificant ( P = 0.12 and p=0.21, respectively). The mean CEA in groups A, B and C was 33(25-43), 35(26-42) and 37(17-53), respectively. CEA did not differ significantly between groups A, B and C ( P = 0.25). Assessment of TC did not differ significantly between the groups ( P = 0.66). Observation of TC in groups B and C combined revealed that the cartilage was open in 65% of 77 patients and 14% of them developed SCS; whereas among the 35% of patients with ossified TC only 7% developed SCS (OR=2.0). PSA and CEA alone have no predictive value in determining the risk of contralateral slip. The absence of TC results in a two-fold decrease in the likelihood of developing an SCS. The decision of prophylactic surgical treatment of the contralateral hip in primary unilateral SCFE should not be based solely on radiographic findings.

Preliminary results of rigid fixation (locking plate/screw) after triple pelvic osteotomy without a hip spica cast: A modified fixation method in 21 patients.

Objectives The aim of this study is to investigate whether rigid fixation after triple pelvic osteotomy (TPO) utilizing a 3.5-mm locking plate and screws without hip spica cast can provide enough stability and prevent correction loss in pediatric patients with developmental dysplasia of the hip (DDH) and Legg-Calvé-Perthes disease (LCPD).Patients and methods A total of 21 hips of 21 pediatric patients (9 males, 12 females; mean age: 9.3±2.0 years; range, 6 to 14 years) who underwent rigid fixation with locking plate/screws after TPO for DDH and LCPD between June 2015 and October 2018 were retrospectively analyzed. Preoperative, immediate postoperative, and six-month follow-up anteroposterior radiographs were compared for the Wiberg’s center-edge angle (CE), Sharp angle, acetabular coverage of the femoral head (ACFH), and center-head distance discrepancy (CHDD). The patient demographics, surgery time, perioperative complications were evaluated.Results Underlying diagnosis were DDH in 14 patients and LCPD in seven patients. In patients with DDH, postoperative evaluation showed significant increase in the mean CE angle (5.6±16.1° vs. 30.5±9.3°, respectively) and ACFH (46.4±16.8% vs. 84.5±12.1%, respectively), and a significant decrease in the mean Sharp angle (55.3±6.2° vs. 35.6±7.8°, respectively) and CHDD (14.6±10.7% vs. 6.2±5.6%, respectively). The final follow-up revealed that there was no correction loss in these parameters. In the patients with LCPD, postoperative evaluation showed a significant increase in the mean CE (20.1±11.1° vs. 38.3±9.6°, respectively) and ACFH (62.9±18% vs. 91.4±10.1%, respectively), and a significant decrease in the mean Sharp angle (46±3.6° vs. 25.2±5.5°, respectively). The final follow-up revealed that there was no correction loss in radiological parameters. No perioperative complications were noted.Conclusion Our study results suggest that rigid fixation construct with a 3.5-mm locking plate and screws without hip spica cast can provide adequate stability to allow early mobilization following TPO in children without any loss of correction, until bony healing at the osteotomy sites.

Prevalence of radiographic hip dysplasia in japanese population-based study

Objectives The purpose of this study was to measure the indices of radiographic developmental dysplasia of the hip (DDH) in a cross-sectional study of an elderly Japanese population. Methods Hip radiographs of 427 informed, voluntary Japanese community-dwelling individuals (279 female and 148 male) aged 50 to 96 years-old were obtained from Miyagawa village in Japan through a health screening. The hip radiographs were measured by a custom-written, semi-automated MATLAB program. The center edge (CE) angle, acetabular roof obliquity (ARO), acetabular head index (AHI), and minimum joint space width (mJSW) were measured. We examined the associations between gender, side-of-hip, and age group on radiographic DDH and hip osteoarthritis (OA). Results The mean CE angle was 31.0°. The mean ARO was 5.8°. The mean AHI was 88.2%. The mean mJSW was 4.0 mm. Of the total population, 29.9% had DDH and 4.0% had hip OA. Of those who had hip OA, 41.2% were secondary OA, and 58.8% were primary OA. The relationship between DDH and OA was not significant. Conclusion DDH is unlikely to be an important cause of hip OA in the present population-based study.

Sex differences in reference values of hip acetabular measurements using computed tomography in Japanese adults and the effect of aging on the measurement parameters

BackgroundIt is very important to understand the acetabular morphology of the normal hip joint to assist in diagnosis and surgical planning of hip disorders. The purpose of the present study was to obtain gender-based reference values for the acetabular measurements of a normal hip using computed tomography data and investigate the effect of aging on the measurement values. MethodsWe measured acetabular parameters (center-edge angle, Sharp angle, vertical center anterior angle, acetabular anteversion) on computed tomography corrected for changing the obliquity, rotation, and tilt of the pelvis. We performed measurements in 245 patients (490 joints; 120 men [240 joints] and 125 women [250 joints]). The mean age was 64.7 ± 14.3 (31–88) years for men and 63.2 ± 15.2 (30–88) years for women. ResultsIn men and women, the mean center-edge angle was 31.8° ± 6.4° and 30.6° ± 6.5°, the mean Sharp angle was 38.6° ± 3.2° and 40.6° ± 3.8°, the mean vertical center anterior angle was 44.3° ± 7.9° and 40.0° ± 8.5°, and the mean acetabular anteversion angle was 14.3° ± 5.2° and 18.8° ± 5.4°, respectively. All differences were statistically significant. The center-edge angle increased with age in women; however, such an effect was not observed in men. The other measurements showed a similar trend, such as larger vertical center anterior angle and smaller Sharp and acetabular anteversion angles, with aging in both men and women. ConclusionsWe used computed tomography data to quantitatively assess the coverage and shape of the acetabulum in adult Japanese subjects and obtain the estimated reference ranges by gender. The results also proved that the measurements changed with aging in both sexes. These facts must be taken into account during the diagnosis of hip disease and planning of surgery.

Acetabular center-edge angle and prevalence of acetabular dysplasia among adult residents of Albaha province, Saudi Arabia, a hospital-based cross-sectional study

Background: Center-edge angle of Wiberg has been used for a long time to assess femoral head coverage by the acetabulum. However, only few studies have measured this angle in the Saudi population. Furthermore, there are very few studies conducted to study the influence of wither the tribe which an individual belongs to can affect the value of this angle. Purpose: To establish a normal value of center-edge angle of the hip in adult Saudi resident of Albaha region, Saudi Arabia, and to determine whether certain variables such as age, gender, side of hip and tribe affect Center-edge angle. Study design: Cross-Sectional study, Level 3 evidence. Methodology: The center-edge angle of the acetabulum of 436 patients (872 hips) was measured. The association between the value of this angle and the patient’s age, gender, side of the hip, and the tribe was studied. The prevalence of acetabular dyspepsia based on this angle was also calculated. Results: The mean center-edge angle was 38.96˚ (±5.89˚). There was a statistically significant relationship between age and the mean value of the center-edge angle. There was no statistically significant relationship between the value of center-edge angle and gender, side of the hip, or tribe of the patient. Conclusion: The value of the center-edge angle in our study group was higher than what was reported by Wiberg and the previous studies. It was found that there is a proportional relationship between age and value of the center-edge angle. The prevalence of acetabular dysplasia in our study group was very low compared to previous studies.

Center-edge angle values in healthy children between 5 and 14 years old in Turkey.

The aim of this study was to determine the center-edge angle (CEA) values according to age, gender and side in healthy children between 5 and 14 years old in Turkey and to find out the angular limit values for mild and severe dysplasia. The data pool that was gathered to investigate the frequency of hip dislocation in children between 6 months and 14 years old in Turkey was used. The data pool consists of pelvis and lower abdomen radiographs obtained for reasons other than hip dysplasia. Lower abdomen/pelvis radiographies of children between 5 and 14 years old were extracted from the data pool and were evaluated. Distribution of CEA values according to age, gender and side was examined. Measurements were performed by a single investigator on computer by using a standard method. Reliability of the measurements was tested by three different investigators on randomly selected films by using the standard method. CEA values of 3192 hips of 1596 children, who had no hip pathology, were measured. Mean CEA value was found as 26.2°±5.5°. The mean CEA was 26.2°±5.3° in males (%54) and 26.2°±5.7° in females (%46) (p=0.224). Mean values for the right and left hips were 25.7°±5.4° and 26.6°±5.6°, respectively. CEA value of 449 (14%) hips of 333 (20.8%) children was at the limit of mild dysplasia and CEA value of 70 (2.2%) hips of 58 (3.6%) children was at the limit of severe dysplasia. CEA values had increased by age and mild and severe dysplasia limits were determined for every age group. The mild and severe dysplasia values that are defined according to ages in Turkish population will guide the investigators in the diagnosis, follow-up and treatment planning of developmental dysplasia. Level IV, Diagnostic Study.

Pelvic Bone Deformity and Its Correlation with Acetabular Center-edge Angle.

Objective The purpose of the present study was to evaluate the pelvic bone deformities and its correlation with the acetabular center-edge (CE) angle. Methods Between August 2014 and April 2015, we prospectively evaluated patients aged between 20 and 60 years old. The exclusion criteria were: metabolic disease, previous hip or spine surgery, radiograph showing hip arthrosis ≥ Tönnis two, severe hip dysplasia, global acetabular overcoverage, acetabular crossover sign, hip deformities from slipped capital femoral epiphysis (SCFE) or Leg-Perthes-Calveé, and bad quality radiographs. At anteroposterior (AP) pelvic radiographs, we have evaluated: the CE angle, the acetabular index (IA), the acetabular crossover sign, the vertical and horizontal superior and inferior pelvic axis (H1: Horizontal line 1, superior pelvic axis; H2: Horizontal line 2, superior pelvic axis; V1: Vertical line, superior pelvic axis; HR: Horizontal line, inferior pelvic axis; VR: Vertical line, inferior pelvic axis). The superior and inferior pelvic axis were considered asymmetric when there was a difference ≥ 5 mm between both sides. Patients were divided into two groups: control and group 1. Results A total of 228 patients (456 hips) were evaluated in the period. According to the established criteria, 93 patients were included. The mean age was 39.9 years old (20 to 60 years old, standard deviation [SD] = 10,5), and the mean CE angle in the right hip was 31.5° (20 o to 40°), and in the left 32.3° (20 o to 40°). The control group had 38 patients, with asymmetric H1 in 4 cases (10.5%), H2 in 5 (13.1%), V1 in 7 (18.4%), HR in 5 (13.1%) and VR in 1 (2.63%). Group 1 had 55 patients, with asymmetric H1 in 24 cases (43.6%), H2 in 50 (90.9%), V1 in 28 (50.9%), HR in 16 (29.09%) and VR in 8 (14.5%). Comparing both groups, there was statistical significance for H1, H2 and V1 asymmetry ( p < 0.001). Conclusion In the present paper, we observed the correlation between variation in the acetabular CE angle and asymmetry of the superior hemipelvis. The present authors believe that a better understanding of the pelvic morphologic alterations allows a greater facility in the diagnosis of hip articular deformities.

Cross-Sectional Survey of Childhood Acetabular Development in Japan.

Introduction: We aimed to clarify childhood acetabular development and to identify the incidence of children’s hip dysplasia in Japan using radiographs of the contralateral hip. Methods: We performed radiological cross-sectional evaluation of hip development in 211 patients (106 boys, 211 hips) in different age groups (age range: 3–9 years). We excluded patients who complained of bilateral coxalgia at the first visit or had received a diagnosis of acetabular dysplasia. We measured the acetabular index (AI), center-edge angle (CEA), and acetabular head index (AHI) in plain radiographs taken at the first visit. Results: A significant correlation was found between age and CEA in boys, but other parameters had no significant correlation. The mean AI values in boys and girls were 18 ± 3° and 20 ± 4° (p < 0.01), respectively, and the mean CEA values were 25 ± 5° and 24 ± 5° (p = 0.43), respectively. The mean AHI values in boys and girls were 83 ± 6% and 81 ± 7%, respectively (p < 0.01). Two of the 120 children (66 boys and 54 girls) aged ≥6 years old had a hip CEA < 15°; both were girls. Conclusions: We found decreased acetabular development in girls, and 4% (2/54) of girls without any history of dislocation belonged to Severin’s group III. Acetabular dysplasia was observed more frequently in children from Japanese than in those from other countries. Girls with less than two standard deviations in hip dysplasia indices had an AI of 28°, an AHI of 67%, and a CEA of 14°. These reference values may be useful as prognostic indicators for hip dysplasia and OA in adulthood.

What Are the Reference Values and Associated Factors for Center-edge Angle and Alpha Angle? A Population-based Study.

The available evidence regarding normal ranges for the center-edge angle and the alpha angle derives from a few small studies, and associated factors such as sex and anthropometric factors have not been well evaluated. Knowing more about normal values for these parameters is critical, because this can inform decisions about when to perform elective hip preservation surgery. Population-level studies would provide considerable clarity on these issues, but to our knowledge, no such studies are available. The purposes of this study were (1) to use MRI in patients of a population-based study to establish normal values for the alpha and center-edge angles in the normal adult hip; and (2) to determine whether age, sex, or anthropometric variables were associated with differences in these values. We used MRI images (1.5 T) of 3226 participants of the Study of Health in Pomerania (SHIP). SHIP is a population-based study that started with 4308 participants in 1997. Participants were recruited randomly from official inhabitant data files as a stratified cluster sample of the population from a defined region in northeastern Germany. To ensure a representative epidemiologic cohort, stratification variables were sex, age, and city of residence. Between 2008 and 2012, 1094 of these participants underwent whole-body MRI with pelvic sequences in the second followup. In parallel, the next cohort, SHIP-Trend, started with the same protocol in which 2132 participants underwent MRI examination. Reference values were calculated by quantile regressions for the 2.5 and 97.5 percentiles. Associations with the demographic features sex, age, weight, height, body mass index (BMI), and waist circumference were analyzed by bivariate linear regression models. The mean center-edge angle was 31° (± 7°) with a corresponding calculated normal range of 17° to 45°. The mean alpha angle was 55° (± 8°) with a corresponding calculated normal range between 39° and 71°. Men (30° ± 7°) had a lower center-edge angle than women (32° ± 8°) (p < 0.001, β = 1.4°; 95% confidence interval [CI], 0.9°-1.9°) and a higher alpha angle (57° ± 8° versus 52° ± 7°, p < 0.001, β = 5.7°; 95% CI, 5.2°-6.3°). Moreover, a higher center-edge angle for the left side was found (33° ± 8° versus 30° ± 8°, p < 0.001, β =3.2°; 95% CI, 3.0°-3.4°). In addition to sex, we found that age, height, waist circumference, and BMI affected both center-edge angle and alpha angle. Weight was associated with the alpha angle as well. Because of these associations, age- and sex-adjusted reference values with belonging formulas were calculated. The range of normal center-edge and alpha angles is quite wide. Therefore, only markedly abnormal angles may be associated with pathology. Moreover, center-edge angle and alpha angle are associated with age, sex, and anthropometric factors, which have to be taken into account for better interpretation. The association of abnormal radiographic values with true clinical hip pathology is tenuous at best. Assuming that a patient with an abnormal radiograph requires treatment is unwise. The clinical picture has to be substantial for therapeutic decisions.

The early radiological effects of Dega and Pemberton osteotomies on hip development in children aged 4-8 years with developmental dysplasia of the hip.

We aimed to investigate the early radiological effects of Dega and Pemberton iliac osteotomies that were performed in patients aged 4-8 years with developmental dysplasia of the hip on development of hip joint. Dega osteotomy or Pemberton osteotomy was performed in 76 hips of 58 patients because of developmental dysplasia of the hip between September 2011 and June 2015 and were evaluated retrospectively. Of a total of 76 hips, Pemberton osteotomy was performed on 39 (19 unilateral) and Dega osteotomy was performed on 37 (21 unilateral). In all hips, the acetabular index, acetabular depth ratio, centre-edge angle of Wiberg, and Reimer's index values were recorded preoperatively and at the final follow-up. We measured the surface areas of the femoral head ossific nucleus in patients with unilateral dysplastic hips and compared results before both osteotomy procedures and at the final follow-up. There were no statistically significant differences between the groups in terms of the acetabular index and acetabular depth ratio values (P>0.05) preoperatively and at the final follow-up, but the mean centre-edge angle of Wiberg and Reimer's index values showed significant statistical differences in favor of the Dega procedure (P<0.05). There was a statistically significant difference in favor of the Pemberton procedure when the mean ratio of the surface area of the femoral head ossific nucleus on the dysplastic side in relation to the normal side was compared preoperatively (P=0.042) and at the final follow-up (P=0.027) in unilateral hips. Although Dega and Pemberton osteotomies produce satisfactory radiological outcomes at early stages in children aged 4-8 years with developmental dysplasia of the hip, a higher rate in the surface area of the femoral head ossific nucleus was observed in the Pemberton osteotomy group, which also had a lower mean age than the Dega osteotomy group.

Successful Pavlik Harness Treatment for Developmental Dysplasia of the Hip and Normal X-Ray at the Age of 2 Years: Is a Longer Follow-up Necessary?

Management of developmental dysplasia of the hip (DDH) with a Pavlik harness is a well-known treatment.Follow-up until skeletal maturity is recommended as long-term studies mention late sequelae.The purpose of this study was to determine whether such a follow-up is necessary in patients treated successfully under a strict protocol. A retrospective review of a consecutive series of normal infants treated for DDH between January 1995 and July 2004 was undertaken.Only normal infants with frankly pathologic hips treated successfully with a Pavlik harness were included, and with a normal anteroposterior (AP) pelvis x-ray at the age of 2 years.All infants with any type of neurological disease, syndrome, other form of treatment for DDH, and failure of the Pavlik harness were excluded.At the last follow-up, a clinical examination and a standing AP pelvis x-ray were performed. A total of 109 hips in 83 children were available for review. The mean follow-up was of 10 years and 2 months. All 109 hips had a normal clinical examination and a normal AP pelvis x-ray: a mean center-edge angle (CEA) of 29.5 degrees, SD±4.1 degrees, a mean acetabular index (AI) of 1457±3.74 degrees, a mean Sharp's angle of 41.92±3.42 degrees, a Seringe-Severin score of IA, a normal teardrop figure, no signs of avascular necrosis, and Moses circles <2. This study strongly suggests that in a selected group of patients treated for DDH with a Pavlik harness, under a strict protocol, and a normal x-ray at 2 years of age, a long-term follow-up is not necessary. Level III-therapeutic.

Assessment of hip development in the early period in patients who underwent dega osteotomy due to developmental dysplasia of the hip

Objective: To examine hip development in a patient who underwent Dega osteotomy due to developmental dysplasia of the hip (DDH) by means of radiography. Materials and Methods: Dega osteotomy was performed on 43 hips (7 were bilateral) of 36 patients with DDH. In preoperative and final follow-up; the acetabular index (AI), acetabular depth ratio (ADR) and Wiberg's center-edge angle (CEA) were measured in anteroposterior pelvic radiographs. Hips were classified in accordance with Tonnis classification system. Radiological findings were evaluated in accordance with Severin classification system. Avascular necrosis (AVN) of the hips were evaluated according to Kalamchi-MacEwen classification system. Results: The mean age was 87 months (48-130 months), mean follow-up period was 30.5 months (15-62 months). The mean preoperative and final follow-up values of AI were 43° (28°to 60°) and 19° (6° to 34°), respectively. The mean preoperative and final follow-up values of ADR were detected as 14 (8 to 24) and 26 (18 to 42), respectively.The mean CEA was found as 38° (18° to 61°) at the final follow-up. Of the hips, 37 were Tonnis type 4 and 6 were Type 3. Totally 10 hips had AVN; of those, 6 were Type 1, 2 were Type 2 and 2 were Type 3 hips. According to Severin classification, 11 hips were Type 1a, 3 were Type 1b, 22 were Type 2a, 5 were Type 2b and 2 were Type 3. Conclusion: In patients who underwent Dega osteotomy, hip development can be detected radiographically with satisfactory levels.

Long-term Results of Modified Salter Innominate Osteotomy for Legg-Calvé-Perthes Disease.

BackgroundIn a previous study, we reported clinical and radiographic results of our modified Salter innominate osteotomy technique in 16 hips affected by Legg-Calvé-Perthes disease (LCPD) with an average follow-up of 31.8 months. In this study, we present the long-term results of the osteotomy in LCPD patients followed until physeal closure.MethodsThirty hips of 29 patients were followed until skeletal maturation after modified Salter innominate osteotomy. The mean follow-up duration was 12.9 years (range, 9.1 to 16.0 years). Eleven hips (36.7%) were classified as Catterall group III and 19 (63.3%) as Catterall group VI. Stable interposition of a bone block was achieved using one biodegradable screw in nine hips and without any fixation device in 21 hips by simply changing the direction of osteotomy. The Harris Hip Score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and hip function were evaluated at the last follow-up. Radiological outcomes were evaluated using Wiberg's center-edge angle, the Mose method, and Stulberg classification, and osteoarthritic changes were evaluated using the Tonnis classification.ResultsMean HHS and WOMAC score were 80.2 points and 54 points, respectively, preoperatively and these were improved to 96.2 points and 28 points, respectively, at the last follow-up. Clinical results, according to Robinson's criteria, were good in 18, fair in seven, and poor in five hips. Radiological results assessed using the Mose method were good in 18, fair in six, and poor in six hips, and according to the Stulberg classification, nine hips were class I, nine were class II, eight were class III, and four were class IV. The mean center-edge angle improved from 19.7° preoperatively to 29.6° at the final follow-up. According the Tonnis classification, three hips were grade 2, five were grade 1, and 22 were grade 0. Of the three grade 2 hips, two underwent Chiari osteotomy 12.1 and 8.8 years postoperatively, and the other underwent total hip arthroplasty 12.9 years postoperatively.ConclusionsThe modified Salter innominate osteotomy produced relatively satisfactory long-term clinical and radiological results.