CE Angle Research Articles

Short follow-up evaluation of proximal femoral varus osteotomy for treatment of Legg-Calvé-Perthes disease.

BackgroundThere are many methods of treating Legg–Calvé–Perthes disease, including operative and nonoperative methods. Femoral varus osteotomy is one of the surgical methods used to treat this disease, and it involves changing the alignment of the proximal femur to improve containment of the femoral epiphysis in the acetabulum. The aims of this study were to evaluate the results of femoral varus osteotomy for the treatment of Perthes disease according to various classification and grading schemes, as well as to compare the results to those obtained using other methods of treatment reported in the literature.Materials and methodsTwenty-three patients with Legg–Calvé–Perthes disease were treated using a proximal femoral varus osteotomy procedure. The mean age of the patients was 7.8 years (range: 6–11.5 years). The average follow-up was 36.2 months (range: 29–48 months).ResultsThe patients were classified and graded according to the Catterall and Herring classifications. The preoperative and postoperative mean epiphyseal extrusion indices were as follows: group III (B), 10.88 % and 7.22 %, P = 0.027; group III (BC), 15.81 and 8.93 %, P = 0.005; group IV (C), 72.64 and 39.44 %, P = 0.018. The preoperative and the postoperative mean Wiberg’s CE angle were as follows: group III (B), 26.88° and 37.81°, P = 0.028; group III (BC), 24.4° and 32.2°, P = 0.005; group IV (C), 20.89° and 28.41°, P = 0.018. Changes in Iowa clinical hip scores were as follows: group III (B), 54.8 to 92.33, P = 0.027; group III (BC), 47.3 to 87.8, P = 0.005; group IV (C) 34.43 to 68.29, P = 0.017. In the last follow-up, the mean limb length discrepancy after plate removal was 0.9 cm (range: 0.0–2 cm) of shortening on the operated side. The author of the present study did not see any progressive change in this parameter during the follow-up period, especially after hardware removal and in the younger boys. All of the osteotomies united within 3 months without loss of fixation.ConclusionAccording to the results of the present study, proximal femoral varus osteotomy gives good results in children between the ages of 6 and 10 years without any femoral head deformity and flattening, especially with good containment in abduction.Level of evidenceLevel IV.

Investigation of association between hip morphology and prevalence of osteoarthritis.

The cause of hip osteoarthritis (OA) remains unclear, morphologic abnormality of hip was thought to be a contributing factor to hip OA. The hypothesis was that there were subtle anatomical morphology differences of the hip between normal and OA subjects; the objective of this study was to explore these anatomical differences which are predisposing to hip OA based on CT 3D reconstruction. Ninety-three normal subjects (186 hips) and 66 mild-to-moderate hip OA subjects (132 hips) were recruited in this study. Three parameters of the head-neck relationship were assessed: translation, rotation and concavity. Translation was the potential translational movements of femoral head related to the neck’s axis. Rotation was described by the physeal scar to evaluate the rotation tendency of femoral head related to the neck at the head-neck junction. Concavity was used to assess the sphericity of the head as it joins the neck. The femoral neck anteversion angle and some parameters of the acetabulum: anteversion, inclination and CE angle were measured too. By comparison, it was found that OA subjects had less femoral head sphericity, head-neck junction concavity, acetabular and femoral neck anteversion angle; but greater acetabular coverage. These characteristics increased the risk of hip OA in OA subjects.

How Often Does Femoroacetabular Impingement Occur After an Innominate Osteotomy for Acetabular Dysplasia?

Femoroacetabular impingement is increasingly recognized as a cause of hip pain but its incidence after an innominate osteotomy for the correction of acetabular dysplasia has not been determined. This information would be essential for the orthopaedic surgeon because it has the potential to produce a poor outcome in the long term when trying to balance acetabular instability and overcorrection. The purposes of our study were (1) to determine the frequency with which clinically relevant femoroacetabular impingement (FAI) occurs after an innominate osteotomy for the treatment of acetabular dysplasia; (2) to determine risk factors for the development of FAI; and (3) to compare postoperative radiographic and clinical outcomes in patients having undergone an innominate osteotomy for the correction of acetabular dysplasia both with and without FAI. This was a retrospective review of 154 hips (132 patients) that had undergone an innominate osteotomy for acetabular dysplasia and were evaluated at a minimum followup of 10 years (mean = 12 years). Mean age at the time of surgery was 3 years, 114 hips had a concomitant open reduction, and 54 hips also had femoral shortening. One hundred eight hips had a Salter osteotomy and 46 had a Pemberton osteotomy. Radiographs were analyzed to determine the lateral center-edge angle (CE angle) and the presence of a crossover sign. The diagnosis of FAI was established when the CE angle was greater than 40°, there was a positive crossover sign, and the patient had groin pain when flexing the hip less than 90°. Comparisons between nonparametric variables were performed with a Mann-Whitney's U test. Categorical variables were compared with a chi-square test. Change in acetabular index (correction) was dichotomized considering 20° of correction as the cutoff point. Association is presented as odds ratio (95% confidence interval), and logistic regression was performed. According to our criteria, 18 of 154 hips had FAI (12%). Of the 18 patients with FAI, 10 had undergone a Pemberton osteotomy (10 of 46 [22%]) and eight a Salter osteotomy (eight of 108 [7%]). A change in the postoperative acetabular index greater than 20° was associated with a greater likelihood of developing FAI. The mean postoperative acetabular index was lower for the group with FAI, for whom it was 20°, compared with the group without FAI, for whom it was 27° (p = 0.04). The mean Iowa Hip Score for the group with FAI was 85, whereas for those without FAI, it was 93 (p = 0.03). FAI is not common after an innominate osteotomy for the treatment of acetabular dysplasia; however, overcorrection is related to a higher incidence. When FAI is present, it can affect the outcome. Overcorrection should be avoided when performing an innominate osteotomy for the treatment of acetabular dysplasia because it can create iatrogenic FAI and have an adverse effect on outcome. Level III, therapeutic study.

A pitfall through the failure cases of hip arthroscopy for the labrum tear

Objectives The acetabular labrum tear has been considered the most common cause of groin pain and the most frequent hip pathology. We have performed arthroscopic treatments for the labrum tear without obvious hip dysplasia. The purpose of this study is to investigate clinical outcomes of arthroscopic treatments in patients with labrum tear and to clarify the character of failure cases of hip arthroscopy for the labrum tear. Methods Seventy-four patients (78 hips) with CE angle more than 20°, who had labrum tear and were treated arthroscopically, were included in this study. The mean age at the primary hip arthroscopy was 42 years (12–68 years), and the mean follow-up period was 40 months (24–90 months). The labrum tear was treated with labrum debridement in 31 hips and labrum re-fixation in 47 hips. Clinical outcomes were evaluated using modified Harris Hip Score (mHHS), and fair or poor cases were investigated. FAI-related findings, including cross-over sign (COS),? angle, pistol grip deformity (PGD), head/neck offset ratio were radiographically observed. Results The mean mHHS revealed improvement from 71 points to 89 points after surgery. Progression of osteoarthritis was observed in 8 hips. Radiographical evaluation revealed mild COS in 22 hips, PGD in 10 hips. The mean? angle was 63° and the mean head-neck offset ratio was 0.14. Overall FAI-related findings were positive in 43 hips (55%). Ten patients (14%) including 4 patients with osteoarthritis were regarded as poor cases due to the pain score less than 20 points, and their symptoms occurred on long walking or the motion of external rotation without reference to FAI-related findings or procedures for the labrum tear. Four poor cases without FAI-related findings and osteoarthrisis had partial labrum tear and groin pain on walking or mild external rotaion. Moreover, extra-articular injection was effective in these cases. Discussion and conclusions Ten patients (14%) was considered poor cases after hip arthroscopy for the labrum tear. Even if the labrum tear is suspected on preoperative examinations, the cause of groin pain is not necessarily derived from the torn labrum. Surgeons should take not only intra-articular pathology but also extra-articular pathology into consideration before decision of arthroscopic treatment. Understanding genuine cause of groin pain in each patient would help to improve the results of hip arthroscopy.

Caput valgum associated with developmental dysplasia of the hip: management by transphyseal screw fixation.

PurposeA late finding of some hips treated for developmental dysplasia of the hip (DDH) is a growth disturbance of the lateral proximal femoral physis, which results in caput valgum and possibly osteoarthritis. Current treatment options include complete epiphysiodesis of the proximal femoral physis or a corrective proximal femoral osteotomy. Alternatively, a transphyseal screw through the inferomedial proximal femoral physis that preserves superolateral growth might improve this deformity.MethodsThis study evaluates the effect of such a transphyseal screw on both femoral and acetabular development in patients with caput valgum following open treatment of DDH. These patients were followed clinically and radiographically until skeletal maturity. Preoperative and postoperative radiographs were assessed, measuring the proximal femoral physeal orientation (PFPO), the head–shaft angle (HSA), Sharp’s angle and the center edge angle of Wiberg (CE angle).ResultsThirteen hips of 11 consecutive patients were followed prospectively. The age at the time of transphyseal screw placement was between 5 and 14 years. The mean improvement of the PFPO and HSA was 14° (p < 0.01) and 11° (p < 0.001), respectively. The mean improvement of Sharp’s angle and CE angle was 4.7° (p < 0.01) and 5.8° (p < 0.02), respectively. Five patients underwent screw revision.ConclusionsA transphyseal screw across the proximal femoral physis improved the proximal femur and acetabular geometry.

Displasia del desarrollo de la cadera en niños con trastorno psicomotor. ¿Factor de riesgo para un mal resultado?

IntroductionOrthopaedic treatment of developmental dysplasia of the hip (DDH) has a high success rate in cases that are diagnosed early. However, the outcomes of these patients are not really known when they are subsequently diagnosed with some type of cerebral impairment. Materials and methodsA retrospective observational study was conducted on cases of DDH with a poor outcome after orthopaedic treatment, being unknown if they had any type of psychomotor disorder. The patients were clinically and radiologically assessed, and afterwards received neurological valuation by the Child Neurology Unit. ResultsOf the 325 cases of DDH diagnosed in 293 patients, 10 patients (3%) with 16 hips with DDH were diagnosed of any cerebral impairment. All them were initially treated orthopedically. Clinical and radiologically evolution was succesful only in 4 cases (25%) being necessary any surgical procedure in the remaining 12 cases. After surgical treatment we got an improvement in the Acetabular Index (p=0.005) and Reimers Extrusion Index (p=0.042). Neck-shaft angle and Wiberg CE angle also improved but this difference was not statically significant. Cerebral impairment was diagnosed at 2,5 years of age and the begining of walking was delayed at 2.4 years of age. ConclusionsCerebral impairment can lead to an unfavourable outcome in the treatment of DDH, with the relative risk of a poor outcome being 7.2 times higher in these patients.An unfavourable outcome with conventional treatment of DDH must make us suspect the presence of some type of neurological disorder, particularly if there is a delay in walking.

Extracapsular approach for arthroscopic treatment of femoroacetabular impingement: clinical and radiographic results and complications

ObjectivesTo evaluate the clinical and radiographic results and complications relating to patients undergoing arthroscopic treatment for femoroacetabular impingement by means of an extracapsular approach. MethodsBetween January 2011 and March 2012, 49 patients (50 hips) underwent arthroscopic treatment for femoroacetabular impingement, performed by the hip surgery team of the Orthopedic Hospital of Passo Fundo, Rio Grande do Sul. Forty patients (41 hips) fulfilled all the requirements for this study. The mean follow-up was 29.1 months. The patients were assessed clinically by means of the Harris Hip score, as modified by Byrd (MHHS), the Non-Arthritic Hip score (NAHS) and the internal rotation of the hip. Their hips were also evaluated radiographically, with measurement of the CE angle, dimensions of the joint space, alpha angle, neck-head index, degree of arthrosis and presence of heterotopic ossification of the hip. ResultsOut of the 41 hips treated, 31 (75.6%) presented good or excellent clinical results. There was a mean postoperative increase of 22.1 points for the MHHS, 21.5 for the NAHS and 16.4̊ for the internal rotation of the hip (p<0.001). Regarding the radiographic evaluation, correction to normal values was observed for the alpha angle and neck-head index, with a mean postoperative decrease of 32.9̊ and mean increase of 0.10, respectively (p<0.001). ConclusionArthroscopic treatment of femoroacetabular impingement by means of an extracapsular approach presented satisfactory clinical and radiographic results over a mean follow-up of 29.1 months, with few complications.

Biomechanical analysis and clinical efficacy of eccentric rotational acetabular osteotomy

Objective To investigate the biomechanical mechanism and report preliminary clinical efficacy of eccentric rotational acetabular osteotomy (ERAO) when conduct treatment for developmental dysplasia of the hip (DDH). Methods Biome-chanical model of the hip joint was established on six female cadaveric hips embalmed by formalin and stimulate ERAO was then performed on the model. Vertical force was loaded on the cadaveric spine from 0 N to 500 N and strain value on femoral head was measured preoperatively and postoperatively when loading force on spine reached the point of 100, 200, 300, 400 and 500 N. Stress value were then calculated base on the measurements. Besides, we reported postoperative follow-up cases which were underwent ERAO to treat DDH in our hospital from July 2007 to October 2014. A total of 25 patients (26 hips) were reported, including 6 males and 19 females. Age varies from 11 to 57 years old, and the average age was 31 years old. Postoperative hip function was evaluated by Harris hip score and anteroposterior X-ray of pelvic was taken preoperatively and postoperatively to measure the acetabular-head index (AHI), CE angle and sharp angle. Results Preoperative stress increased when loaded on spine became larger, but postoperative stress changed its increasing trend into decreasing when the load was greater than 300 N (turning point), which showed a parabolic trend. Compared with the preoperative stress under different load varying from 100 N to 500 N, postoperative stress was not statistically significant. Meanwhile, by the end of follow-up period, 18 patients (19 hips) were followed form 7 to 85 months. The average follow-up time was 40 months and the follow-up rate was 72%. Harris hip score improved from preoperative 64.3±7.2 points to 85.6±5.3 points; postoperative AHI increased an average of 36.5%, CE angle increased an average of 33.1° and sharp angle reduced an average of 12.3°. All differences between preand post-operative indexes were statistically significant. Conclusion ERAO has the ability to correct the deformity of acetabulum. It enlarges the acetabular coverage of the femoral head and thus reduces the pressure of weight-bearing area. Key words: Hip dislocation, congenital; Osteotomy; Acetabulum; Biomechanics

Abordagem extracapsular para tratamento artroscópico de impacto femoroacetabular: resultados clínicos, radiográficos e complicações

ObjectivesTo evaluate the clinical and radiographic results and complications relating to patients undergoing arthroscopic treatment for femoroacetabular impingement by means of an extracapsular approach. MethodsBetween January 2011 and March 2012, 49 patients (50 hips) underwent arthroscopic treatment for femoroacetabular impingement, performed by the hip surgery team of the Orthopedic Hospital of Passo Fundo, Rio Grande do Sul. Forty patients (41 hips) fulfilled all the requirements for this study. The mean follow‐up was 29.1 months. The patients were assessed clinically by means of the Harris Hip score, as modified by Byrd (MHHS), the Non‐Arthritic Hip score (NAHS) and the internal rotation of the hip. Their hips were also evaluated radiographically, with measurement of the CE angle, dimensions of the joint space, alpha angle, neck‐head index, degree of arthrosis and presence of heterotopic ossification of the hip. ResultsOut of the 41 hips treated, 31 (75.6%) presented good or excellent clinical results. There was a mean postoperative increase of 22.1 points for the MHHS, 21.5 for the NAHS and 16.4° for the internal rotation of the hip (p<0.001). Regarding the radiographic evaluation, correction to normal values was observed for the alpha angle and neck‐head index, with a mean postoperative decrease of 32.9o and mean increase of 0.10, respectively (p<0.001). ConclusionArthroscopic treatment of femoroacetabular impingement by means of an extracapsular approach presented satisfactory clinical and radiographic results over a mean follow‐up of 29.1 months, with few complications.

Long term results of open reduction and Salter osteotomy for developmental dislocation of the hip in children

Objective To retrospectively review long-term results of developmental dislocation of the hip patients treated with open reduction and Salter pelvic osteotomy, and to analyze the potential risk factors. Methods Sixty-eight developmental dislocation of the hip cases （81 hips） were treated with open reduction and Salter pelvic osteotomy from September 1992 to Octo- ber 2002, 45 eases （52 hips） were followed up to skeletal maturity. None had undergone other treatment before the key surgery. Some cases received skeleton traction before surgery. The radiographic and functional results were assessed at last follow-up. The possible relevant factors for unsatisfactory outcome were analyzed. The correlation between type Ⅱ AVN and the coverage rate of the femoral head were evaluated. Results The mean age at surgery was 2.5 years （ranged from 1.4 to 5.3 years）. At last follow-up, 44 hips （84.6%） had excellent or good functional results. 23 hips （44.2%） had avascular necrosis of varying severity, of which 16 hips were type Ⅱ. There was significant relevance between the AVN severity and the Severin classification result （P=0.018）. The ＂over correction＂ hips, that were overcorrected during surgery, were more likely to get severe type AVN （P=0.037）. There was no correlation between Type Ⅱ AVN with uncoverage according to CE angle and Reimers index （P=0.457, 0.308 respectively）. Conclusion 1） Satisfactory functional and radiographic results could be expected in developmental dislocation of the hip cases with- out AVN; 2） High risk of AVN existed in the late diagnosised hips that underwent open reduction and Salter pelvic osteotomy, type Ⅱ was the most common type; 3） Type Ⅱ AVN was not a predictor for progressive femoral head coverage deficiency; 4） ＂Over correction＂ in Salter pelvic osteotomy was related with severe type AVN which should be avoided. Key words: Hip dislocation, congenital; Child; Osteotomy; Femur head necrosis; Follow-up studies

Surgical implications for residual subluxation after closed reduction for developmental dislocation of the hip: a long-term follow-up.

Untreated residual subluxation after early closed reduction for developmental dislocation of the hip (DDH) leads to early degenerative osteoarthritis. The aim of our study was to investigate the role of early surgical timing and its indications. Thirty-six patients (48 hips) with untreated residual subluxation after closed reduction who had serial follow-up radiographs until they had reached skeletal maturity were retrospectively reviewed. The average age at closed reduction was 1.6 years and at the last follow-up 13.8 years. The last radiographs were evaluated according to the Severin classification: Severin grades I and II were defined as satisfactory and Severin grades III and IV as unsatisfactory. Several measurements of the acetabular index (AI), Reimer's index (RI), center edge angle of Wiberg (CE angle) and orientation of the sourcil of the acetabulum were evaluated. The satisfactory group comprised 18/48 hips (37%), whereas the unsatisfactory group comprised 30/48 hips (63%). The average RI in the unsatisfactory group was significantly worse than that in the satisfactory group at the age of ≥3-4 years, as was the average CE angle at the age of ≥4-5 years and AI at the age of ≥5-6 years. As remodeling occurs over time, some subluxations diagnosed at age of 2-3 years developed into normal hips. At 3-4 years, 42 hips were still subluxed; 71% of these had unsatisfactory final Severin grades. At 4-5 years, 30 hips were still subluxed; 87% of these had unsatisfactory Severin grades (III and IV). Very little remodeling after the age of 5 years. Eighteen/18 hips with (34.4% ± 4.5% vs 43.0% ± 4.6%, P < 0.00) RI >38% at the age of 3-4 years fell into the unsatisfactory (21.0° ± 5.5° vs 10.6° ± 5.2°, P < 0.01) group. In addition, 26/30 hips with RI >33% at the age of 4-5 years were in the unsatisfactory group, as were 26/26 hips with upward sourcil orientation. To avoid early osteoarthritis, surgery correction of residual subluxation is recommended when the RI >38% at the age of 3-4 years or the RI >33% with the sourcil upward at the age of 4-5 years.

Three-dimensional kinetic simulation before and after rotational acetabular osteotomy

BackgroundSome reports indicate that one of major causes of clinical failure after periacetabular osteotomy is development of secondary femoroacetabular impingement (FAI). To assess the impact of range of motion (ROM) on the increase in FAI following rotational acetabular osteotomy (RAO), we performed FAI simulations before and after RAO. MethodsWe evaluated 12 hips that had undergone RAO (study group), and 12 normal hips (control group). The study group was evaluated before and after surgery. Morphological parameters were evaluated to assess acetabular coverage. The acetabular anteversion angle, anterior CE angle, alpha angle, and combined anteversion angle were also measured. Impingement simulations were performed using 3D-CT. The ROM which causes bone-to-bone impingement was evaluated in flexion (flex), abduction, external rotation at 0° flexion, and internal rotation at 90° flexion. The lesions caused by impingement were evaluated. ResultsRadiographic measurements indicated improved postoperative acetabular coverage in the study group. The crossover sign was recognized pre- and postoperatively in every case in the study group and in no cases in the control group. In the simulation study, flexion, abduction, and internal rotation at 90° flexion decreased postoperatively. Impingement occurred within 45° internal rotation at 90° flexion in two preoperative and nine postoperative cases. The impingement lesions were anterosuperior of the acetabulum in all cases. There were correlations between anterior CE angle, CE angle, acetabular anteversion angle, and hip flexion angle. There were also correlations between the anterior CE angle, combined anteversion angle, and angle of internal rotation at 90° flexion. ConclusionsIn the postoperative simulation, there was a tendency to reduce the ROM in flexion, abduction, and internal rotation at 90° flexion due to impingement. Since there were more cases which caused impingement within 45° internal rotation at 90° flexion after RAO, we consider there is a potential for increased FAI after RAO.

Correlation between bone apposition of the acetabular rim and morphological indicators of femoroacetabular impingement in the japanese asymptomatic population

Purpose: Acetabular rim ossification has been generally accepted as an osteophyte, which appeared in advanced osteoarthritis of the hip. On the contrary, it is suggested that bone apposition of the acetabular rim was induced by femoroacetabular impingement (FAI), abnormal abutment of the femoral neck against the acetabulum. FAI has been well described as a pathologic process that can lead to early osteoarthritic changes. To date, the association between the bone apposition of the acetabular rim and FAI is still unknown. The purpose of this study is to evaluate the association between the presence of bone apposition of the acetabular rim and morphological indicators of FAI based on computed tomography (CT) examination. Methods: We reviewed the CT scans of 245 consecutive subjects (490 hips, age: 21–83 years) who underwent abdominal and pelvic CT from September, 2010 to June, 2011. These subjects were mainly examined for abdominal disorders. We confirmed that no subject had any symptoms for the hip joint by the questionnaire survey. We reviewed them to evaluate the presence of bone apposition of the acetabular rim and the morphological abnormalities of the femoral head and acetabulum. The multi-detector CT adjusted for the anterior and lateral inclination of the acetabulum was obtained. On these images, 3 radial sections, antero-, mid-, and postero-superior, were determined at 30 degrees interval. Each section passed through the midpoint of the acetabulum and crossed vertically to the acetabular margin. Bone apposition of the acetabular rim was diagnosed by the recess sign, which is characterized as a gap between the native acetabular rim and the extension of the osseous apposition. We measured following three signs as indicators for FAI: a angle, center edge angle (CE angle), and acetabular index (AI). At the time of measurement, the position of the pelvis was standardized. We defined an anterior pelvic plane involving the anterior superior iliac spines and the top of the pubis as a reference plane (coronal section). Mann–Whitney U-test was used for statistical analysis. Results: Bone apposition was observed in 156 hips (32%) in total of the three parts. The prevalence at each part, anterior, middle, and posterior was 3.4%, 13.6%, and 24.6% respectively. When we divided the subjects into the younger group (<60 years old) and the elderly group (S60years old), there was significant difference at the prevalence of bone apposition between two groups (younger: 18.3%, elderly: 44.6%; p < 0.01). In terms of the a angle and CE angle, there was no significant difference between the subjects with and without bone apposition (a angle: 45.8 7.3 vs 43.4 8.4 , CE angle: 32.6 5.5 vs 31.7 8.1 , respectively). Interestingly, there was different trend in AI between the younger and elderly groups. The younger group showed no significant difference between the subjects with and without bone appositionwith the AI of 3.1 3.7 vs 4.3 5.2 , whereas the elderly group showed significant difference with the AI of 4.4 2.1 for with the bone apposition group vs 2.9 3.4 for without bone apposition group, p < 0.05. Conclusions: Two different types of FAI have been described, one is cam impingement, which is caused by small offset of femoral head neck junction, and the other is pincer impingement that is attributed by the acetabular over-coverage. Pincer impingement was thought to be associated with ossification of the acetabular rim. It was reported that the bone apposition in FAI initiated from subperiosteal bone formation at the rim, which was distinct from osteophyte formation in OA, which is a result of endochondral ossification from articular cartilage. In the present study, we showed that the prevalence of bone apposition was 32%. It was observed more frequently at the posterior part of the acetabulum and in the elderly subjects of asymptomatic Japanese population. Moreover, statistical analysis revealed significantly larger AI, means shallow joint, in the subjects with bone apposition in the elderly population. These results indicate that the bone apposition of the acetabular rim may have degenerative characteristics without clinical symptoms and might be associated with the instability of the hip joint.

Prevalence of radiographic markers of femoroacetabular impingement in asymptomatic adults.

to determine the prevalence of radiographic signs of femoroacetabular impingement (FAI) in asymptomatic adults and correlate them with data from physical examinations. We conducted a cross-sectional study with 82 asymptomatic volunteers, 164 hips, between 40 and 60 years of age, selected by convenience. They were submitted to anamnesis and clinical examination of the hip, anteroposterior (AP) pelvis radiographs with three incidences, Dunn 45° and Lequesne false profile of each hip, to measure the variables. We measured the alpha angle, anterior offset of the femoral neck, cervical diaphyseal angle, CE angle of Wiberg, acetabular index, Sharp angle, and the crossing, ischial spine and posterior wall signs. our sample consisted of 66% women, mean age of 50.4 years. The average alpha angle was 45.10°, SD=8.6. One quarter of the hips showed alpha angle greater than or equal to 50°; among men the prevalence was 34%, and among women, 11%. We found indicative radiographic signs of femoroacetabular impingement in 42.6% of hips, whether femoral or acetabular, and the increased alpha angle was related to the decrease in hip internal rotation (p<0.001). the radiographic findings of femoroacetabular impingement in asymptomatic patients were frequent in the studied sample. The increase in alpha angle was associated with decreased internal rotation.

Besonderheiten in der Behandlung des Hüftgelenks bei Kindern mit dem Down-Syndrom

The treatment of hip instability in patients with Down syndrome is challenging. We have performed different pelvic osteotomies and corrections at the proximal femur for this indication. This retrospective study was conducted to evaluate the clinical and radiological outcome of each intervention. All in all, 166 patients with Down syndrome were treated at our orthopaedic department in the observation period. Problems related to the hip joint were diagnosed in 63 of those patients. Only patients who underwent surgery were included in this study. The charts and X-rays of these 31 patients were evaluated with respect to the following parameters: incidence of the hip problem, concomitant diseases, temporal progress, kind of operation method and date, duration of stay in the hospital, after-care, follow-on surgery related to complications, AC angle, CE angle, ACM angle, CCD angle, index of migration according to Reimers, classification of Bauer and Kerschbauer and general morphology of the femoral head. The group was compared with an age-matched group of 21 patients with hip dysplasia. Those patients underwent the same sort of operation in the same year. In the Morbus Down group, we performed surgery for preservation of the hip in 49 cases. This included 13 osteotomies according to Chiari, 11 triple osteotomies according to Tönnis, 10 corrections by femoral varus derotation osteotomy, 8 pelvic osteotomies according to Pemberton, 5 pelvic osteotomies according to Salter and 2 open reductions of the hip. With respect to the moment of surgery, we detected three peaks of age. There was no difference in course of disease and quantity of complications between the groups. Satisfactory results concerning clinical and radiological outcome were achieved predominantly by complete redirectional acetabular osteotomies. Half of the patients who were solely treated by femoral varus derotation osteotomy needed follow-on surgery in the form of pelvic osteotomy. Comparison of preoperative and postoperative range of motion of the hip joint between groups detected capsular insufficiency, increased ligamentous laxity and muscular hypotonia in patients with Down syndrome. Comparison of pelvic radiographs demonstrated significant improvement concerning measured angles in both groups. Preoperative values with respect to AC angle and CE angle were demonstrated to be lower in the hip dysplasia group (p < 0.01); whereas values for ACM angle were comparable between groups. Hypermobility and secondary dislocation of the hip joint is a common problem in patients with Down syndrome, which often requires surgical intervention at an early stage. According to our data and clinical results we suggest a complete redirectional acetabular osteotomy in combination with capsular plication for treatment of this challenging condition.

Prévalence des anomalies acétabulaires associées à une déformation en crosse de pistolet dans la coxarthrose

Acetabular retroversion, excessive acetabular coverage and abnormal head-neck-junction with a so-called “pistol-grip-deformity” were added to the classical description of hip dysplasia to describe pathological hip morphology. The aim of the current study was the detection of pathological acetabular geometry in patients with an abnormal head-neck-junction. Femoro-acetabular impingement and hip dysplasia features are frequent in patients with end-stage osteoarthritis before 60 years of age. We analysed our data bank retrospectively for all patients who received a Total Hip Arthroplasty (THA) due to end-stage osteoarthritis before the age of 60 years. The pelvic-views and the Dunn-view of these patients were screened for an abnormal head-neck-junction by measuring the head-ratio and the alpha-angle. An orthopaedic surgeon and a radiologist did this independently. These radiographies were measured for signs of acetabular dysplasia, excessive acetabular coverage and crossing sign. A consecutive series of 135 total hip arthroplasties were performed in patients aged less or equal to 60 years because of end-stage osteoarthritis. From these, 81 patients were classified as having an abnormal head-neck-junction. The mean head-ratio in these 81 patients was 1.52 ± 0.35, the mean alpha-angle was 62.5° ± 9.3°. The mean CE-angle of these 81 patients was 35.8° ± 10.4°, the mean CA-angle was 36.7° ± 5.7°, the mean depth-width-ratio was 49.1 ± 10, the mean extrusion-index was 19.1 ± 9.2 and the mean CCD-angle was 131.7° ± 7.3°. Of these 81 hips, 14 had isolated pistol grip deformity, while 11 hips had associated dysplasia, 38 had excessive acetabular coverage, and 14 had crossing sign. In addition, a crossing sign was identified in four of the 11 dysplastic hips and 19 of the 38 of the hips having excessive acetabular coverage. There was no statistically significant difference in regard to the age between the four groups ( P = 0.087). In contrast, the hips that had excessive acetabular coverage had increased CE angle (44.6° ± 7.2°) and decreased extrusion index (12.6 ± 6.5) ( P < 0.001), while dysplastic hips had increased roof obliquity (17.5° ± 4.5°) and increased extrusion index (29.6 ± 9.1) as well as decreased CE-angle (20.7° ± 3.0°) ( P < 0.001). There is a high coincidence of radiographic findings associated with an abnormal head-neck-junction consisting in excessive acetabular coverage and retroversion as well as hip dysplasia. These results advocate for restoring of the normal anatomy at the early stage to prevent end-stage osteoarthritis. Level IV retrospective historical study.

Die Häufigkeit einer verminderten Pfannenanteversion bei asymptomatischen Patienten: eine retrospektive Analyse

In patients with unilateral femoroacetabular impingement (FAI), bony characteristics predisposing to FAI (e.g., acetabular retroversion) are also commonly observed in the contralateral asymptomatic hip. This study investigated the prevalence of these characteristics in an asymptomatic population and the influence of pelvic inclination and tilt on acetabular anteversion. In this study, patients with unspecific abdominal pain in whom CT including the hip was performed to aid diagnosis were included. Exclusion criteria were previous fractures of the acetabulum or the femur and surgical pretreatment of the hip. AV, CE angle, CCD angle and the distance between the anterior and posterior acetabular rims were determined. 11.5 % of the 400 included hip joints had a central AV of < 15°. A central retroversion was not found. Female patients had a significantly higher AV compared to males (p < 0.05). Pelvic tilt and inclination had a significant influence on the AV. Correct assessment of AV is dependent on a correct pelvic radiograph. 16.5 % of the hips of asymptomatic patients had at least one bony characteristic predisposing to FAI.

Impact of triple pelvic osteotomy on contact stress pressure distribution in the hip joint

We studied changes of contact stress distribution in the hip joint after Tonnis triple pelvic osteotomy applied in the treatment of dysplasia and hip joint incongruence in adolescents. In a group of 75 patients, 54 (72 %) female, who underwent surgery by triple pelvic osteotomy in adolescence for developmental disorder of the hip and avascular necrosis of the femoral head, a three-dimensional hip joint model was used based on the radiography of the pelvis with hips. The following biomechanical parameters were calculated: resultant hip force normalised to body weight (R/Wb), inclination of the resultant hip force (θ-R), the position of the stress pole (θ), peak contact hip stress (Pmax), and peak contact hip stress normalised to body weight (Pmax/Wb). Gait quality was also assessed. After surgery the Wiberg CE angle was increased by 17.85° (114 %), resultant hip force normalised to body weight (R/Wb) was decreased by 0.107 (3.3 %), the position of the stress pole was shifted medially by 27.59° (63.5 %), and peak contact hip stress normalised to body weight (Pmax/Wb) was decreased by 2249.74 (55.9 %). Waddling gait was reduced from 17 (23.9 %) to four cases (5.6 %). All changes were statistically highly significant (p<0.01). The effect of Tonnis triple pelvic osteotomy lies in the improvement of stress distribution across the acetabular cartilage of the hip joint, thus slowing down the degenerative damage of the hip joint.

Evaluation of radial distribution of cartilage degeneration and necessity of pre-contrast measurements using radial dGEMRIC in adults with acetabular dysplasia

BackgroundThe purpose of the present study was to investigate the radial distribution patterns of cartilage degeneration in dysplastic hips at different stages of secondary osteoarthritis (OA) by using radial delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), and to assess whether pre-contrast measurements are necessary.MethodsThirty-five hips in 21 subjects (mean age ± SD, 27.6 ± 10.8 years) with acetabular dysplasia (lateral CE angle < 25°) were studied. Severity of OA was assessed on radiographs using Tönnis grading. Pre- (T1pre) and post-contrast T1 (T1Gd) values were measured at 7 sub-regions on radial reformatted slices acquired from a 3-dimensional (3D) T1 mapping sequence using a 1.5 T MR scanner. Values of radial T1pre, T1Gd and ΔR1 (1/T1Gd - 1/T1pre) of subgroups with different severity of OA were compared to those of the subgroup without OA using nonparametric tests, and bivariate linear Pearson correlations between radial T1Gd and ΔR1 were analyzed for each subgroup.ResultsCompared to the subgroup without OA, the subgroup with mild OA was observed with a significant decrease in T1Gd in the anterosuperior to superior sub-regions (mean, 476 ~ 507 ms, p = 0.026 ~ 0.042) and a significant increase in ΔR1 in the anterosuperior to superoposterior and posterior sub-regions (mean, 0.93 ~ 1.37 s-1, p = 0.012 ~ 0.042). The subgroup with moderate to severe OA was observed with a significant overall decrease in T1Gd (mean, 404 ~ 452 ms, p = 0.001 ~ 0.020) and an increase in ΔR1 (mean, 1.17 ~1.69 s-1, p = 0.001 ~ 0.020). High correlations were observed between radial T1Gd and ΔR1 for all subgroups (r = −0.869 ~ −0.944, p < 0.001).ConclusionsRadial dGEMRIC without pre-contrast measurements is useful for evaluating different patterns of cartilage degeneration in the entire hip joint of patients with hip dysplasia, particularly for those in early stages of secondary OA.

Effect of Pelvic Osteotomy in the Skeletally Immature on Acetabular Coverage

Although pelvic osteotomy in children has been effective in re-establishing containment of the hip joint, its impact on hip joint development with respect to acetabular coverage is ill defined. The purpose of this study is to determine the prevalence of acetabular overcoverage in patients who had pelvic osteotomy during childhood and its impact on patient function. Between 1980 and 2008, all patients who had a pelvic osteotomy done at our institution for non-neuropathic hip dysplasia (DDH) or secondary to Legg-Calvé-Perthes disease (LCP) prior to skeletal maturity were reviewed. A clinical assessment and the WOMAC, UCLA Activity Score, Marx activity score, and SF-36 quality-of-life questionnaires were completed. A standardized AP pelvic X-ray was performed to determine the acetabular coverage, signs of retroversion, and degenerative changes. Twenty-eight patients (32 hips) were identified, of which 14 (9 DDH, 5 LCP) agreed to participate. Impingement sign was positive in eight patients (six DDH, two LCP). Crossover and ischial spine signs were each present in ten hips. Tonnis grades were: 0 in 1 hip, 1 in 10 hips, 2 in 2 hips, and 3 in 1 hip. The mean Tonnis angle was 11.6 ± 8.6°. The mean CE angle was 24.0 ± 15.9° with six hips having a CE angle <20° and one hip with a CE angle >40°. There was no correlation between crossover sign or ischial sign and Tonnis grade (p = 0.739), hip pain (p = 0.520), or impingement sign (p = 1.00). Acetabular overcoverage is common in patients who underwent pelvic osteotomy during childhood. No correlation was identified between retroversion and hip pain in our patient cohort.