Magnetic resonance tomography in diagnosis and therapy follow-up of patients with congenital hip dysplasia and hip dislocation

PROBLEM: Human chrionic gonadotropin (hCG) is a placental glycoprotein hormone, a heterodimeric molecule, consisting of alpha and beta chains. It induces the synthesis of progesterone, which is essential for the maintenance of the fertilized egg. Antibodies directed against hCG can, therefore, prevent pregnancy and serve as a vaccine. hCG belongs to the glycoprotein hormone family and shares the alpha chain with the other members. The beta chain is a hormone-specific subunit that is unique to hCG, but still possesses 85% amino acid homology with the beta chain of luteinizing hormone (LH), which means that prolonged immunization with hCG produces antibodies that cross-react with LH. METHOD OF STUDY: We have taken an approach involving the mutation of beta hCG to eliminate cross-reactive epitopes without affecting the natural folding of the polypeptide chain and thus the unique beta hCG-specific epitopes. RESULTS: Several mutants have been constructed that have maintained the binding to hCG-specific monoclonal antibodies (mAbs) but have lost the ability to bind to a panel of LH cross-reactive mAbs. To investigate the immunogenicity of selected mutants, mice were immunized with expression plasmid DNA, containing the gene for wild-type beta hCG and two mutants: mutant 3, with four amino acid substitutions (68 Arg-->Glu; 74 Arg-->Ser; 75 Gly-->His; 79 Val-->His), and mutant 7, with a single amino acid substitution (68 Arg-->Glu). CONCLUSIONS: Although both mutants were able to elicit antibody responses in at least some animals, the levels were less than those seen with the wild-type beta hCG DNA, and there seems still to be a residual cross-reactivity with LH. Attempts to improve the immunogenicity of the mutants and to further modify the sequence to remove the cross-reactivity are currently underway.     

Perinatal observations on the etiology of congenital dislocation of the hip

At least 1 per cent of all newborn infants in the United Kingdom have CDH (Fig 10). Among these infants, approximately 85 per cent are normally formed and 15 per cent malformed. Among the normally formed infants, 90 per cent of the CDH are of the Grade 1 type, and 10 per cent of Grades 2 and 3. Such infants have a perinatal mortality of about 5 per cent. In contrast, among the malformed infants, about 50 per cent are CDH Grade 1, and 50 per cent Grades 2 and 3; their perinatal mortality is around 70 per cent. In other words, a much higher proportion than usual of the severe grades of CDH are found among the infants with a high perinatal mortality.     

Magnetic resonance tomography in congenital hip dysplasia and dislocation

The Oncology Home Care Service in Basel provides nursing support to let cancer sufferers choose where they receive palliative care. Most of the cost is borne by the patient's health insurance.     

Open reduction and varus-detorsion osteotomy with femoral shortening in treatment of congenital dislocation of the hip

In this study, we clinically and radiographically evaluated open reduction with shortening of the femur in children more than 1 year old with refractory congenital dislocation of the hip. In 19 children (aged 1-4 years), 22 joints were operated on. The patients were followed-up for an average of 8.7 years (range, 2-13 years). Functional results were satisfactory in all joints, and differences in limb length were not significant. Radiographically, good results (grades I and II) were obtained in 16 of the 22 joints, according to Severin's criteria. This surgical procedure may be indispensable for treating refractory congenital dislocation of the hip in children over 1 year old.     

An evaluation of conservative and operative methods in the treatment of congenital hip dislocation

An evaluation of different methods of closed reduction of dislocated hips during different periods of time shows that manual reduction and fixation in Lorenz position account for a high rate of avascular necrosis. Even with functional and slow reduction by Pavlik harness and overhead extension, there is still a certain percentage of femoral capital necrosis. The fetal position recommended by Fettweis and Salter seems to reduce the incidence of necrosis. Acetabuloplasty combined with detorsion-varus-ostcotomy provides the means of normalizing a hip joint with a greater degree of success than most other methods.     

Screening for congenital dislocation of the hip by physiotherapists. Results of a ten-year study

We report a prospective study of the feasibility of employing specially trained physiotherapists to screen neonates for congenital dislocation of the hip. During ten years 42,241 babies were screened, using clinical tests; 255 were diagnosed and treated by a Pavlik harness. In the same period 13 children presented late with congenital dislocation of the hip which had not been detected by the screening programme.     

Gait analysis of adult paraplegic rats after spinal cord repair

This study presents a novel detailed method of analysis of rat gait and uses this method to demonstrate recovery of forward locomotion patterns in adult rats made paraplegic by surgical spinal cord transection and subjected to a novel strategy for spinal cord repair. Six normal rats were compared to five animals in which the cord was transected at T8-T9, and a 5-mm segment of the spinal cord removed, and to seven animals in which, following spinal cord transection and removal of a spinal cord segment, multiple intercostal peripheral nerve bridges were implanted, rerouting pathways from white to gray matter in both directions. The implanted area was filled with fibrin glue containing acidic fibroblast growth factor. Details of the repair strategy have been published (H. Cheng, Y. Cao, and L. Olson, 1996, Science 273: 510-513). Gait analysis was carried out 3 and 4 months after surgery and once in the normal animals. Animals were allowed to walk across a runway with a transparent floor. Each test consisted of five trials, and each trial was videorecorded from underneath. Using frame-by-frame playback, individual footprints were then recorded regarding location and order of limb use, as well as step quality (degree of weight bearing, etc.). These data allowed measuring runway transit time, five different measures of step numbers, all possible temporal patterns of limb use, stride length, and base of support. Transected controls remained paralyzed in the hindlimbs with only occasional reflex hindlimb movements without weight bearing. Animals subjected to the full repair procedure were significantly faster than the controls, used their hindlimbs for 25-30% of the movements, and regained several of the specific limb recruitment patterns used by normal rats. Taken together, the gait analysis data demonstrate remarkable recovery of coordinated gait in the repaired animals, which was significantly better than controls for all relevant parameters, while at the same time clearly inferior to normal rats for most of the examined parameters. We conclude that normal rats use a multitude of interchangeable step sequence patterns, and that our spinal cord repair strategy leads to recovery of some of these patterns following complete spinal cord transection. These data suggest functionally relevant neuronal communication across the lesion.     

A finite element analysis of factors influencing total hip dislocation

A previously validated three-dimensional finite element model was used to study how several total hip component design and surgical placement variables contribute to resisting the propensity for posterior dislocation in the case of leg crossing in an erectly seated position. The computational formulation incorporated treatments of polyethylene material nonlinearity and large displacement sliding contact. The primary outcome measures were the peak intrinsic moment developed to resist dislocation, and the ranges of motion before neck on lip impingement and before frank dislocation. Modifications of the acetabular linear design (chamfer bevel angle, lip breadth, head center inset) involved trading off improved peak resisting moment for compromised range of motion and vice versa. Increases of head size led to substantial improvements in peak resisting moment, but if the head to neck diameter ratio was held constant, had almost no influence on the component range of motion. For the leg crossing event studied, increased component anteversion, and even more so increased tilt (less net abduction), achieved improvements in range of motion and in peak resisting moment, but these changes imply diminished resistance to anterior dislocation from extension and adduction motion inputs.     

Isolated traumatic dislocation of the hip. Long-term results in 50 patients

From 1974 to 1989, we treated 50 patients with a simple dislocation of the hip: 38 were posterior dislocations and 12 were anterior. All dislocations primarily treated at our hospital were reduced by closed methods within three hours (mean 85 minutes (10 to 180)) and 43 were reviewed after an average follow-up of 8 years (2 to 17). It is widely held that isolated hip dislocation reduced within six hours gives an excellent outcome, but we found a significant number of complications. There were radiological signs of partial avascular necrosis in two, mild osteoarthritis in seven, and moderate degeneration in two. Heterotopic ossification was seen in four patients, but 29 of 33 MRI examinations were normal. Objective evaluation according to the Thompson and Epstein (1951) criteria showed fair and poor results in 3 of 12 anterior dislocations, but in 16 of 30 posterior dislocations. In six of the seven patients with no other severe injury, the hip had an excellent or good result; in only three of the eight patients with severe multiple injuries was this the case. The important factors in the long-term prognosis appear to be the direction of the dislocation and the overall severity of injuries.     

Acetabular growth potential in congenital dislocation of the hip and some factors upon which it may depend

The factors which determine the rate and amount of acetabular growth in congenital dislocation of the hip are ill-understood. A prospective radiological study has been devised in order to assess the influence of the age of congruity, femoral anteversion and neck/shaft angles on acetabular growth. To be included, the children must have reached at least 8 years of age. Those with associated congenital abnormalities and subluxation were excluded, as were those who had operations for acetabular reconstruction. Seventy-four hips were suitable for analysis, and the age range at follow-up was from 8 to 17 years. The acetabular angle was used as an index of acetabular growth. Measurement of this angle, and the anteversion and neck/shaft angles were made before, and each year after reduction of the hip. Congruity was assessed from a radiograph with the legs in the functional position. A satisfactory acetabulum was obtained in 44 hips and the mean age of congruity was 33 months; the acetabulum was unsatisfactory in 30 hips, with a mean age of congruity of 48 months. Four years is the critical age, for if congruity is obtained later, the risk of producing a moderate or severely dysplastic acetabulum is more than doubled. If congruity is obtained under four years of age, growth of the acetabulum with continue in most patients up to 8 and in some to 11 YEARS OF age; the resulting acetabulum was normal or mildly dysplastic. Fifty-nine per cent of the satisfactory hips at follow-up had a normal anteversion angle, and 6 per cent a normal neck/shaft angle. Correction of these angles by themselves, seems not to be a major importance for promoting acetabular growth.     

Bilateral traumatic hip dislocation with bilateral sciatic nerve injury

Bilateral traumatic dislocation of the hip is a rare injury. In fact, only about 50 cases have been reported previously. We report a case of traumatic bilateral posterior hip dislocation with bilateral sciatic nerve damage suffered in a traffic accident by a 65-year-old woman.