Reliability of Hip Migration Index in Children with Cerebral Palsy: The Classic and Modified Methods

OBJECTIVE: To determine reliability and clinical use of two methods of migration index (MI) in CP patients with or without hip dysplasia. METHOD: The materials included radiographs of 200 hips of children with cerebral palsy. Conventional anteroposterior radiographs of the pelvis were taken with the child in the supine position with standardized methods. Two rehabilitation doctors measured the migration index using two methods. In the classic method, the lateral margin of the acetabular roof was used as a landmark and in the modified method the lateral margin of the sourcil was used as a landmark. Each rater measured the migration index at three separate times with a time interval of at least one week. Intraclass correlation (ICC) was used to test the inter- and intra-rater reliability. RESULTS: MI shows excellent intra-rater reliability in both the classic and modified methods, but the inter-rater reliability was higher in the classic method than in the modified method. When categorized according to the sourcil classification, inter-rater reliability was higher in the normal sourcil type and lower in the dysplastic sourcil types. CONCLUSION: Generally, the classic method showed higher reliability than the modified method, even though the reliability of the MI measurement was relatively high with both methods.

Early Subluxation of Hip in Children with Cerebral Palsy

OBJECTIVE: Hip deformity is one of the common problems in children with cerebral palsy. And it is important to detect hip subluxation or dislocation as early as possible. The purpose of this study is to find the incidence of hip subluxation in early childhood in patients with cerebral palsy. METHOD: We reviewed clinical and radiological records of children with cerebral palsy under 36 months of age. We measured migration index, acetabular index, center edge angle and neck shaft angle from hip X-ray of patients. RESULTS: Total 76 patients were included in this study. The mean of migration index was 4.5+/-7.5% at 8~12 months, 10.9+/-11.9% at 13~24 months, and 18.2+/-13.0% at 25~36 months (p<0.05). Twenty one patients (27.6%) were above 25% on the migration index. The neuromotor type of cerebral palsy in 21 patients with hip subluxation, were spastic in 20 (95.2%) except one child. The incidence of hip subluxation was 25.0% (8/32) for quadriplegia, 29.6% (8/27) for diplegia and 50.0% (4/8) for hemiplegia. The acetabular index was significantly higher and the center edge angle was lower in the subluxated hip group than in the non-subluxated hip group, though no significant difference in the neck shaft angle. CONCLUSION: We concluded that the hip subluxation in cerebral palsy can occur under 36 months of age with a relatively high incidence. Therefore, it is recommended to evaluate the hip of cerebral palsy with radiological as well as clinical examination in early childhood.

Legg-Calve-Perthes Disease: The Clinico-Radiological Analysis of 101 Hips of 89 Patients / 대한정형외과학회잡지

The object of treatment of Legg-Calve-Perthes disease (L.C.P.D.) is to shorten the clinical course and minimize, or prevent residual deformity, This is accomplished by placing the femoral head deeply within the acetabulum, so that its articular surface is completely contained and maintaining a full range of motion, thereby preventing lateral extrusion of head, concentrated vertical loads and collapse. The purpose of this study was to determine the predicting value of prognosis and correlation of three different evaluating methods, when examining an identical series of radiographs to assess the effect of treatments, and to determine whether the result obtained by femoral osteotomy gave better result than those by non-surgical means. During the past ten years prior to writing, 89 patients with L.C.P.D. were treated by authors. Seventy eight (87.6%) patients were boys and 11 (12.4%) girls. Their ages at the time of initial visit ranged from 2 to 13 years. Twelve (13.5%) patients had bilateral and 77 had unilateral involvement for a total of 101 hips. They were analysed according to Catteralls classification, and also comparative study was done for 32 patients who were followed up over 15 months. The longest follow-up was 5 years and 2 months. They were divided into 2 groups: clildren in group A were treated by rest and abduction brace,. followed over 3 years and 3 months in average, and children in group B were treated, by intertro-chanteric osteotomy, followed over 2 years and 6 months in average. End results for 32 cases were evaluated at each follow-up time by Length/Width Index (L/W.I.) of femoral neck (Robichon, 1974), Migration Index (M.I.) and Spherical quotient (S.Q.) of capital femoral epiphysis (Edsberg et al, 1979). L/W.I.,M.I, S.Q. were used not only as the method of evaluation, but also were used as a predicting the prospective clinical course during the treatment by regular measurement whether it takes the good course or not. Results obtained were as follows: 1. 21(20.8%) were classified as group I, 30(29.7%) as group Il. 31(30.7%) as group III and 19 (18.8%) as group IV. 43 children (42.6%) on their initial visit were found to have this diasbling hip condition at stage II (necrosis and early fragmentation stage). 2. Regardless of the type of treatment, good results were obtained in younger children under age of 7 years, and in mild form as in group I, and lI. Also good, results were obtained in the cases who had treatment at early stage of the disease. No difference was found in the end results between girls and boys when they had same degree of head involvement. 3. In 14 surgically-treated patients, the good results were obtained in 9(64.3%) when assessed by L/W I. 10(75.4%) by M.I., and 7(50%) by S.Q., while in 18 conservatively treated patients good results were obtained in 8(44.4%) when assessed by L/W I. in 6(33.3%) by M.I., and 7(38.7%) by S.Q.. This fact means that S.Q. under-estimates the results of well-treated cases, while M.I. seemingly over-estimates them. 4. when X-rays of the hips were taken in different position's, different L/W Indices were unexpectedly obtained; these deviations in assessment may be listed as a drawback. Migration Index can prognosticate the healing process of the disease during treatment, if the index together with medial joint space is measured repeatedly with certain intervals. Also it is difficult to obtain accurately the S. Q. by measurements because of difficulty locating the center of fragmentary head, but it is considered the best method assessing the end-result at the healed stage. S.Q. expresses the head spherocity, while the M. I. expresses the degree of head coverage and the neck L/W.I. expresses the indirectly amount of neck deformity. 5. When the clinical course is assessed by three evaluating methods, occasionally these three results contradict to each other and do not show similar prognostic tendency or trend. The reason is that neck L/W Index and Spherical quotient indicate directly the progress of the disease while Migration Inex receases only the state of femoral head containment and there by indirectly indicates ensuing prospective course when containment is good, and do not indicate the state of severity of the involved head. 6. In this study, the result of surgically treated patients were superior to those of conservatively treated patients.