Acetabular index values in healthy Turkish children between 6 months and 8 years of age: a cross-sectional radiological study.

OBJECTIVE: The aim of this study was to determine the normal acetabular index values in children between 6 months and 8 years of age based on sex, age and side and to define the cutoff values for mild and severe acetabular dysplasia. METHODS: The records collected from the data pool that was gathered to define the prevalence of untreated congenital hip dislocation in Turkish children between 6 months and 14 years of age was used. The acetabular index was measured on pelvic and abdominal radiographs of children between 6 months and 8 years of age, taken in 19 different cities for non-dysplasia related causes. The distribution of the index values based on age, sex and side. RESULTS: Thirty-three hips of 21 children (0.75%) out of 2788 children were found to be subluxated or luxated. Acetabular index values of 5534 hips of 2767 children were measured. Acetabular index values of 723 (13%) hips of 493 children (17.8%) were found to be between 1 and 2 standard deviations. Acetabular index values of 147 hips (2.65%) of 118 children (4.3%) were calculated to be above 2 standard deviations. There was a negative correlation between the acetabular index and age. CONCLUSIONS: The study defines the normal acetabular index values in healthy Turkish children between 6 months and 8 years of age and the expected acetabular index values for mild and severe dysplasia.

Evaluation of experienced surgeons' decisions regarding the need for secondary surgery in developmental dysplasia of the hip.

BACKGROUND: We aimed to evaluate experienced surgeons' decisions regarding the need for secondary surgery in developmental dysplasia of the hip (DDH) at 5 to 7 years of age. METHODS: We selected 21 hips from 17 patients who had mid-term and skeletally mature radiographs and who had neither had complications nor secondary surgery until skeletal maturity after having an initial soft tissue surgery for DDH before the age of 18 months. Twenty experienced orthopaedic surgeons evaluated the mid-term follow-up radiographs of these hips in terms of their need for secondary surgery. RESULTS: On the basis of management grading of the observers at mid-term follow-up, the risk of unnecessary surgical management was 12% in hips that would eventually be normal at skeletal maturity. The risk of not performing needed surgery was 40% in hips that would eventually become dysplastic at skeletal maturity. Experience of the surgeons in terms of years had no significant effect on the management decisions. The center-edge angle, the acetabular index angle (AIA), percentage of femoral head coverage, Shenton line, and the acetabular angle of Sharp were the 5 most commonly used radiographic parameters at mid-term follow-up to assess whether a secondary surgery would be needed. Center-edge angle, AIA, femoral head coverage, and Shenton line correlated, whereas the acetabular angle did not significantly correlate with surgeons' quantitative management decisions on the basis of mid-term radiographs. CONCLUSIONS: Experienced surgeons are more likely to opt for nonoperative management in hips that show no ischemic changes or instability at 5 to 7 years of age even in the presence of slightly abnormal radiographic measurements. AIA is considered the best radiographic parameter for making decisions regarding the need for secondary surgery in DDH at 5 to 7 years of age. LEVEL OF EVIDENCE: Level II prognostic study.

Prevalence of untreated hip dislocation in Turkish children aged 6 months to 14 years.

OBJECTIVE: In this study, our aim was to determine the prevalence of untreated hip dislocation and subluxation in Turkey. METHODS: Pelvic radiographs of 4,947 children, aged between 6 months and 14 years, taken for non-orthopedic purposes were requested from 23 provinces around the country. 3,723 radiographs met the study criteria and were evaluated. Dislocated and subluxated hips were identified according to the relationship of femoral head using Perkins line and quadrants. RESULTS: Thirty-five hips in 22 children were found to be dislocated or subluxated. The prevalence rate was calculated as 5.9% CONCLUSION: Despite appearing to have decreased when compared to limited regional prevalence studies, hip dislocation and subluxation prevalence is still unacceptably high. More extensile work should be done to avoid external factors in the etiology of developmental dysplasia of the hip and to organize screening programs in newborns.

Is Kalamchi and MacEwen Group I avascular necrosis of the femoral head harmless in developmental dysplasia of the hip?

The aim of this clinical study was to evaluate the influence of Kalamchi and MacEwen group I avascular necrosis of the femoral head (AVN) on the radiographic and clinical outcomes in developmental dysplasia of the hip (DDH). Preoperative and follow-up (at 2-3, 4-6, 7-9 and 10-15 years of age) Sharp's acetabular angles (AA) and the final Wiberg's center-edge angles (CEA) and proximal femoral center-trochanter distances (CTD) of 13 hips with group I AVN (AVN group) were compared with measurements of 22 hips without AVN (control group). All hips were initially treated by the same soft tissue surgical procedure (posteromedial limited surgery) under the age of 18 months and were completely followed up to at least 10 years of age. Radiographic diagnosis of group I AVN was made between 6 and 12 months postoperatively. The period for complete radiographic recovery of group I ischemic changes was between 2 to 4.5 years. Preoperative mean AA values of both groups were similar. However, the mean AA was found to be worse in the AVN group than in the control group during follow-up. Control group hips had a better mean CEA and higher number of hips having normal CTD than the AVN group, at latest follow-up. In conclusion, when compared with uncomplicated hips, group I ischemic changes retard acetabular development and have quantitative unfavorable effects on lateral femoral head coverage and proximal femoral anatomy in DDH. In addition, the healing process in group I AVN patients is extended.

Ipsilateral teratologic high hip dislocation, femoral hypoplasia and below-knee hemimelia associated with contralateral fibular hemimelia: report of a case with functional result.

In this case report, we present a patient with right teratologic high hip dislocation, femoral hypoplasia and below-knee hemimelia associated with left fibular hemimelia. Combined open reduction, proximal femoral osteotomy and a Dega acetabuloplasty were performed in the right hip. Closed tibial wedge osteotomy and centralization of the foot with lateral release and Achilles tendon lengthening were performed for the left side. The patient was able to walk with her prosthesis successfully within the first six postoperative months.

No detectable major changes in gait analysis after soft tissue release in DDH.

UNLABELLED: The iliopsoas and adductor tendons are often soft tissue barriers obstructing relocation of the femoral head into the acetabulum and are frequently released to obtain reduction. We assessed whether posteromedial soft tissue release including sectioning of the adductor longus and iliopsoas tendons would lead to alterations in joint angles and moments of the hip joint or other major changes in the gait pattern. We conducted 3-D quantitative gait analysis of 10 patients (mean age, 8.1 years) who had unilateral and surgically treated DDH before the age of 18 months. The mean single support time was shorter in the unaffected side of the patients than in the healthy control group. Mean pelvic excursions in both frontal and sagittal planes and maximum knee extension at stance of the affected and unaffected sides were higher in the patients than in the control group. Peak hip flexion moment during swing phase was somewhat reduced, and the hip moment crossover point from extension to flexion was slightly delayed in both the affected and unaffected sides. We could not identify an explanation for the slight deviations due to limited data. However, sectioning of the adductor longus and iliopsoas tendons in DDH patients under 18 months old did not appear to lead to major objective clinical gait alterations. LEVEL OF EVIDENCE: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Posteromedial limited surgery in developmental dysplasia of the hip.

UNLABELLED: We questioned whether our modified soft tissue surgical procedure can provide acceptable results with lower complication rates in developmental dysplasia of the hip (DDH). We retrospectively reviewed 143 patients (185 hips) with a mean age of 11.6 months at operation and a minimum followup of 5 years (mean, 7.5 years; range, 5-13 years). We used a posteromedial approach and sectioned the adductor longus and iliopsoas tendons. If we achieved an arthrographically documented anatomic reduction we closed the incisions; if not, we made an arthrotomy to obtain an anatomic reduction through the same incision at the same session. A hip score indicating an acceptable outcome was obtained in 168 hips (90.8%). We identified osteonecrosis of the femoral head (ON) in 36 (19.5%) hips and redislocation in four (2.2%). Both the ossific nucleus and physis were affected in 10 of the 36 hips with ON. We performed secondary operations in 12 hips (6.5%). Hips of the infants after walking age and hips with higher preoperative dislocation grades, acetabular indices, and ON were more prone to having lower hip scores. Based on the data, we believe routine arthrotomy is not needed during posteromedial surgery in DDH and this modified procedure was safe and effective. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Acetabular development in developmental dysplasia of the hip. A radiographic study in anatomically reduced and uncomplicated hips.

The objective of this prospective, controlled study was to assess the radiographic course of acetabular develop- ment in developmental dysplasia of the hip (DDH). The study consisted of 14 patients (mean age at operation, 12 months; range, 6 to 18 months) from a large, prospective series diagnosed with unilateral DDH and treated by a soft tissue surgical procedure via the posteromedial approach. All patients had intraoperative radiographic anatomic reductions, did not have any type of complica- tion during follow-up, and were followed until at least 10 years of age. Unaffected contralateral hips were used as controls. The acetabular angle of Sharp (AA) was measured to determine acetabular development. Mean follow-up was 112 months. A significant difference (p < 0.005) was observed between the mean AA values of affected and unaffected hips at operation and at the first three follow-up visits (mean age was 24, 41, and 56 months, respectively). This significant difference was not present (p > 0.05) at the latest two follow-up visits (mean age was 90 and 124 months, respectively). It can be concluded that a marked radiographic improvement in acetabular slope occurs within 1 year postoperatively. This improvement continues slowly during the childhood period, and the acetabulum attains previously determined normal AA values at nearly 7 to 8 years of age for those patients whose dysplastic hips were anatomically reduced at less than 18 months of age and for those who did not experience complications during follow-up.

[Surgical treatment of hip dysplasia through the medial approach]. / Gelisimsel kalça displazisinin medial yaklasimla cerrahi tedavisi.

Open reduction of developmental hip dysplasia by the medial approach is one of the effective surgical treatment methods during early childhood. Although surgical approaches, fixation and follow-up methods may vary, successful results can be obtained by the algorithm involving the posteromedial approach and arthrographic evaluation. The aim of open reduction by the medial approach should be to obtain Tönnis grade I arthrographic reduction of the dysplastic hip and to maintain it. Avascular necrosis of the femoral head is a potential complication of this method. Even though actual evaluation of this problem requires monitoring patients until maturity, it is essential that special attention be given to the most effective factors (minimal invasive surgical technique, correct reduction, and appropriate position for fixation) for preventing this complication.

[When should secondary procedures be performed in residual hip dysplasia?]. / Kalici kalça displazisinde ikincil girisim ne zaman yapilmalidir?

Residual hip dysplasia is one of the most important complications following treatment of developmental hip dysplasia. If untreated, this condition will cause problems during maturity. The acetabulum consists of the ilium, ischium, pubis, and the triradiate cartilage lying between them. Interstitial growth from the growth plates of the triradiate cartilage plays an important role in the development of the acetabulum. Concentricity and congruity should be maintained during this development, which is very fast during the first eight years and continues until maturity. Whether residual hip dysplasia will occur can be anticipated by evaluating the factors that are effective on this development during the treatment of developmental hip dysplasia. The main prognostic factors include the age of the patient, concentricity and congruity of the hip, sphericity of the femoral head, the distance from the center to the head, and the thickness of the acetabular roof. Taking these factors into consideration during the follow-up is important to eliminate overtreatment and to assess the success of treatment.

A new, objective radiographic classification system for the assessment of treatment results in developmental dysplasia of the hip.

The new, objective radiographic classification system for the assessment of treatment results in developmental dysplasia of the hip includes three quantitative parameters: centre-edge angle of Wiberg, acetabular angle of Sharp and the centre-trochanter distance. Each parameter is divided into three subgroups and assigned a point score (0, 1 and 2) according to their previously determined values. Besides this, three corrective items on the existence of middle/posterior acetabular deficiency, secondary operation and resubluxation/redislocation are added to the classification system and in the presence of any of these items, one point for each item is extracted from the total points. A total of five or six points represents a satisfactory outcome and less than five points, an unsatisfactory outcome. The new system was found to have adequate intraobserver and interobserver agreement levels. It was also observed that, the gold standard Severin system could lead the raters to obtain somewhat more optimistic results with respect to the new system before and after skeletal maturity. It was concluded that the present system could evaluate both the final radiographic status of the hip and the success or failure of the primary treatment and could be capable of leading orthopaedic surgeons to speak the same language while assessing radiographic results in developmental dysplasia of the hip.

Is concomitant bone surgery necessary at the time of open reduction in developmental dislocation of the hip in children 12-18 months old? Comparison of open reduction in patients younger than 12 months old and those 12-18 months old.

It is controversial to perform bone surgery at the time of open reduction in developmental dislocation of the hip in children 12-18 months old. The purpose of this study is to investigate whether concomitant bone surgery is necessary in patients treated with medial open reduction in this age range. Patients that were under 12 months of age at the time of open reduction were compared with patients that were 12-18 months old. Forty-four hips of 30 patients treated with open reduction through Ferguson's medial approach have been included in the study. Mean follow-up was 19.6 years (13-27.5). Age at the time of open reduction was less than 12 months in 21 hips (group A) and 12 months or more in 23 hips (group B). There was no significant difference between two groups concerning avascular necrosis or unsatisfactory radiological outcome (Severin's groups III and IV). A higher rate of secondary bone surgery was necessary in group B than in group A. Although secondary bone surgery is needed at a higher frequency in children 12-18 months old, the radiological outcome is not significantly different for patients younger than 12 months. Therefore, the recommendation of concomitant bone surgery on a routine basis during open reduction in developmental dislocation of the hip in children 12-18 months old is debatable.

[A new measurement method for the radiographic assessment of the proximal femur: the center-trochanter distance]. / Proksimal femurun radyografik degerlendirmesinde yeni bir ölçüm yöntemi: merkez-trokanter uzakligi.

OBJECTIVES: We developed a new method --measuring the perpendicular distance between the center of the femur head and the tip of the trochanter-- for radiographic assessment of the proximal femur. METHODS: The "center-trochanter distance" (CTD) refers to the perpendicular line drawn to the femoral shaft axis between two parallel lines that pass through the center of the femoral head (C) and the tip of the greater trochanter (T). The measured distance in millimeters is expressed as a positive or negative value depending on the location of the point C, that is, above or below the point T, respectively. Measurements were made on anteroposterior plain radiographs of 200 skeletally immature and 600 skeletally mature hips, all of which had been assessed as normal. Values that were found to be below or above the standard deviation of 1 and 2 of the mathematical means were regarded as "normal" and "pathological", respectively. The reliability of the method was tested in 43 hips that had been surgically treated for developmental dysplasia of the hip and had a long-term follow-up. RESULTS: The center-trochanter distance measured below -5 mm and above 15 mm in the skeletally immature proximal femora, and below -17 mm and above 7 mm in the skeletally mature proximal femora were regarded as "pathologic". The intraobserver (kappa coefficient, 0.92 and 0.81) and interobserver (kappa coefficient 0.88) reliability of the method was found to be excellent. CONCLUSION: The center-trochanter distance may prove to be useful in radiographic assessment of the proximal femur in several hip disorders such as developmental dysplasia of the hip and Legg-Calvé-Perthes disease.

The accuracy and reliability of estimation of lateral pillar height in determining the herring grade in Legg-Calvé-Perthes disease.

The amount of the preserved lateral pillar height (LPH) for assigning Herring grades is estimated during daily practice in Perthes disease. Despite this estimation, Herring classification has been reported to have a good interobserver agreement. The purpose of this study was to investigate whether the amount of preserved LPH has an effect on interobserver agreement. The results of surgeons' estimates were compared with objective measurement results. Good agreement was found among three experienced pediatric orthopaedic surgeons in 50 patients (1 vs. 2, kappa=0.527; 2 vs. 3, kappa=0.526; 1 vs. 3, kappa=0.539). Twenty of these cases had a ratio of the LPH scattered between 0.45 and 0.60 and 0.90 and 0.99 (transition between group B and C, and group A and B). When the borderline cases were evaluated separately, the interobserver reliability was poor (1 vs. 2, kappa=0.194; 2 vs. 3, kappa=0.256; 1 vs. 3, kappa=0.154), which may be explained by misperception of the preserved LPH. If the Herring classification is to be used as the prognostic indicator for deciding among the treatment alternatives, and LPH is the major determinant of the management, measurements should be used instead of estimates, especially in borderline cases.

Open reduction through a medial approach in developmental dislocation of the hip: a follow-up study to skeletal maturity.

Forty-four developmentally dislocated hips occurring in 30 patients with an average age at initial surgery of 10.7 (range 2-19) months underwent medial open reduction by Ferguson's approach. All patients were skeletally mature at most recent evaluation. Mean follow-up was 19.8 (range 13-27.5) years. No redislocation or sub-luxation occurred. Additional surgery was required in 11 hips (25%). Avascular necrosis was detected in nine hips (20%). The acetabular index was decreased and the center-edge angle was increased during follow-up. Excellent or good outcome (Severin group 1 or 2) was observed in 79% of the hips at skeletal maturity. At the most recent evaluation, all but two patients had the highest score on the Iowa Hip Rating. The authors conclude that open reduction through the medial approach is effective in developmental dislocation of the hip. Follow-up until skeletal maturity is necessary for an accurate assessment of treatment.

Treatment of developmental dysplasia of the hip with Pavlik harness: prospective study in Graf type IIc or more severe hips.

Successful treatment of developmental dysplasia of the hip (DDH) is associated with early diagnosis and appropriate treatment. In this prospective study, the results of the treatment with Pavlik harness followed by an abduction brace in patients with severe DDH were presented. Twenty-two hips of 18 patients with a mean age of 14.8+/-5.9 weeks (range, 6-26) when diagnosed were followed for an average of 24.2+/-10.8 months (range, 10-46). The hips were staged according to the classification of Graf with ultrasonography and Pavlik harness was instituted as the first line of treatment in all hips. If there was no improvement of ultrasonographic stage at the third week follow-up the harness treatment was discontinued. After the infant became too large for Pavlik harness an abduction brace was used. In all but one hip the treatment was successful (95.4%). In two hips type I avascular necrosis was noted. Of the dislocated hips 90% were reduced. The Pavlik harness is a safe and effective method of treatment of severe DDH in infancy if potential pitfalls are avoided.

[The effects of arthrographically detected femoral head lateralization and soft tissue interposition during closed reduction of developmental dislocation of the hip on mid-term results]. / Gelisimsel kalça çikiginin kapali redüksiyonunda artrografi ile saptanan yumusak doku interpozisyonu ve lateralizasyonun orta dönem sonuçlar üzerine etkisi.

OBJECTIVES: In a prospective, non-randomized evaluation of patients who underwent surgery under general anesthesia for developmental dislocation of the hip (DDH) at or below 18 months of age, we assessed the mid-term effects of arthrographically documented femoral head lateralization and soft tissue interposition under the acetabular labrum during reduction without opening the hip joint capsule. METHODS: The study included 31 unstable hips of 21 children (mean age 12 months; range 4 to 18 months). After the iliopsoas and adductor longus tendons were sectioned by a medial approach, hip joint arthrography was performed. According to the criteria of Tönnis, all the patients had grade 2 arthrographic reduction and the hip joint capsule was left intact. The mean follow-up was 6.5 years (range 3 to 9.5 years). RESULTS: Avascular necrosis of the femoral head (AVN), redislocation, and secondary operation were seen in 42%, 19%, and 29%, respectively. The physeal plate was involved in nearly half of the hips with AVN. The occurrence of AVN was less in hips treated at the age of below one year. Complications were more frequent in cases in which more than one intraarticular soft tissue obstacles had been documented by arthrography. Avascular necrosis and redislocation were more commonly encountered in hips in which the medial pool size of contrast material exceeded 7 mm than those with sizes between 3 to 7 mm. CONCLUSION: Our mid-term complication rates suggest that the hip joint capsule be opened in order to achieve an anatomical reduction through eliminating intraarticular obstacles when arthrography shows lateralization of the femoral head, soft tissue interposition, and medial pooling of the contrast material following closed reduction of DDH.

Six years of experience with a new surgical algorithm in developmental dysplasia of the hip in children under 18 months of age.

One hundred thirty-seven developmentally dysplastic hips of 107 children with a mean age of 11 months were treated by the same surgical algorithm. Following iliopsoas and adductor longus tenotomies by the Ferguson posteromedial approach, the operation was ended in case of arthrographically documented concentric reduction (Tönnis grade 1 reduction) and an open reduction was performed in case of nonanatomic arthrographic reduction (Tönnis grade 2 or 3 reduction). Mean follow-up was 4.2 years. The need for open reduction increased in preoperatively dislocated hips that were proximally displaced according to the Tönnis classification. Somewhat better latest acetabular index values were seen in hips having lower preoperative dislocation grades that were surgically treated before the age of 12 months. Rates of avascular necrosis of the femoral head, redislocation, and secondary operation were 13%, 1%, and 2%, respectively. The authors concluded that although mid-term results of this new surgical algorithm in developmental dysplasia of the hip was satisfactory in infants younger than 18 months of age, long-term follow-up is needed for better understanding of its use.

Analysis of a radiographic assessment method of acetabular cover in developmental dysplasia of the hip.

The aim of this study was to analyse a radiographic assessment method of acetabular cover (Ogata et al.) in developmental dysplasia of the hip (DDH). Intraobserver and interobserver reliabilities of the method were found to be 'substantial' (agreement ratio 85%, kappa coefficient 0.76) and 'moderate' (agreement ratio 71%, kappa coefficient 0.54), respectively. The percentage of hips considered pathological was significantly higher following the use of the acetabular roof shape classification system (15%) than following the measurement of the centre-edge (CE) angle of Wiberg (3%) in the same hips ( p=0.000). The average CE angle of Ogata values of types 1&2, 3 and 4 acetabula were significantly different, whereas the CE angle of Wiberg ones were not. It was concluded that this classification system was a reliable and reproducible radiological indicator for reflecting the acetabular cover. A careful assessment is needed in types 3 and 4 acetabula, because the use of classical angle measurements on plain radiographs such as the CE angle of Wiberg may carry the risk of overestimation of the radiological hip anatomy in such hips.

How should the acetabular angle of Sharp be measured on a pelvic radiograph?

Four experienced orthopaedic surgeons measured the acetabular angle of Sharp (AA) in 66 hips by using two methods. In the classic method (AA-c), the lateral margin of the acetabular roof was used as the landmark. In the modified method (AA-m), the lateral margin of the sourcil (subchondral bony condensation in the acetabular roof) was used as the landmark. Mean AA-c and AA-m measurements were 44.8 degrees and 48.4 degrees, respectively. Mean intraobserver variations of AA-c and AA-m were 1.8 degrees and 2.1 degrees, respectively. Mean interobserver variations of AA-c and AA-m were 2.1 degrees and 2.6 degrees, respectively. Means obtained using AA-c of normal and defective acetabular roofs were similar, but the difference between AA-m means of different acetabular roof types was significant. The authors conclude that both AA-c and AA-m were reliable measurement methods, but clinical use of AA-m would probably produce better understanding of the radiographic hip anatomy in dysplastic hips.