Biomedical subjects
D Atar
Publications and source records attributed to D Atar.
Intra-operative arthrography in open reduction of congenital hip dislocation.
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The use of a tissue expander in club-foot surgery. A case report and review.
Primary skin closure after the surgical correction of severe club-foot may be difficult. We describe the use of a tissue expander to provide sufficient skin, and review some aspects of the use of the method.
Characterization of the fine specificity of peptide antibodies to HLA-DQ beta-chain molecules.
In an attempt to produce epitope specific antisera which could distinguish two closely associated HLA-DQ beta-chain alleles, we immunized 20 rabbits with synthetic peptides representing sequences from the first domain of the HLA-DQw8 and -DQw7 beta-chain molecules, differing only by one amino acid in position 57. Several of the antisera in immunoblotting specifically recognized either the HLA-DQw7 or the HLA-DQw8 beta-chain allele as previously reported. The fine specificity of the antisera was tested in ELISA using synthetic peptides of varying length as solid phase antigen. Two out of the 20 antisera specifically recognized DQw7 beta peptides and two antisera bound only to DQw8 beta peptides from the region containing the amino acid in position 57. To analyze whether the antisera bound to native HLA-DQ beta-chain molecules, FACS analysis was carried out. Seven of the 20 antisera bound to intact EBV-transformed B-lymphocytes, and one antiserum bound preferentially to HLA-DQw8 positive cells.
Revision surgery in clubfeet.
Twenty-nine reoperated clubfeet were reviewed. The age range of the patients at the time of the revision surgery was 1-12 years. The average follow-up period was 30 months (range 9-36 months). The surgical procedure used most often in the revision surgery was complete soft tissue release alone or combined with plantar release, calcaneocuboid fusion, and capsulotomies of the navicular first-cuneiform joint and the first-cuneiform first-metatarsal joint. In 27 of 29 feet the results were considered acceptable (19 of 29 were rated excellent or good). An algorithm that suggests surgical solutions to a variety of clubfoot deformities in different age groups has been developed, as well as an objective functional rating system to evaluate long-term results in revision clubfoot surgery.
New approach to limb deformities in neuromuscular patients.
Fifteen deformed limbs in 10 patients with neuromuscular problems were treated by the Ilizarov technique. Five patients with cerebral palsy had, respectively, two deformities, two tight hamstrings and knee flexion contractures, and one bilateral external tibial torsion; two patients with spina bifida (L5-S1) had foot deformities; one arthrogrypotic patient had flexion contractures of both knees; one poliomyelitis patient had flexion contractures of both knees and equinovarus deformities of the feet; and one patient with Poland's syndrome had a 90 degree flexion contracture of the wrist. Complications were few, and none compromised full correction which was achieved in nine patients. The Ilizarov method is a new and efficient tool which can be successfully applied in the treatment of neuromuscular patients.
Pediatric update #12. A simplified method for percutaneous epiphysiodesis.
Nine patients have undergone percutaneous epiphysiodesis using a 4.5-mm drill and image intensification fluoroscopy. The minimal surgical exposure resulted in minimal postoperative discomfort, excellent cosmesis, and complete closure of the physis in all patients in three to five months. No complications were encountered. The procedure is easy to perform and reliable.
Cannulated blade plate for proximal femoral varus osteotomy.
Fixation of the osteotomy site in the proximal femur is technically demanding. A new system, which includes cannulated chisels and a cannulated one-piece plate that can be inserted over a guide wire, is suggested. The new system simplifies the procedure and provides stable fixation.
Pediatric update #14. Functional rating system for evaluating the results of clubfoot surgery.
The results obtained in a study of 32 patients with 45 idiopathic clubfoot deformities treated by complete soft-tissue release between 1985 and 1986 were investigated retrospectively. The evaluation was based on a specifically designed functional rating system. The results were graded as follows: 51% excellent, 25% good, 18% fair, and 6% poor.
Site-specific antibodies distinguish single amino acid substitutions in position 57 in HLA-DQ beta-chain alleles associated with insulin-dependent diabetes.
The HLA-DQ beta-chain gene shows a close association with susceptibility or resistance to autoimmune insulin-dependent diabetes mellitus (IDDM) and it has been suggested that the amino acid in position 57 may be of pathogenetic importance. To study the expression of the IDDM associated HLA-DQ beta-chain alleles, we immunized rabbits with 12 to 13 amino acid long peptides representing HLA-DQw7 and -DQw8 allelic sequences, differing only by one amino acid in position 57 being aspartic acid (Asp) and alanine (Ala), respectively. Immunoblot analysis of lymphoblastoid cells showed that several antisera recognized a 29-kDa protein, equivalent to the expected molecular size of the HLA-DQ beta-chain to yield two antisera specific for HLA-DQw7 (pos. 57Asp) and three antisera for HLA-DQw8 (pos. 57Ala) positive cells. Analysis of HLA-DR 3/4 positive IDDM patients (n = 24) and controls (n = 19) showed that all (100%) patients were positive for pos. 57Ala antiserum compared to 13 of 19 (68%) of the controls. The remaining six controls reacted with the pos. 57Asp antisera, whereas none of the patients did. We have therefore successfully been able to generate site-specific antibodies that distinguish single amino acid substitutions in predetermined positions of allelic HLA-DQ beta-chain gene products. Such sera should become useful to detect and investigate HLA associated susceptibility to autoimmune diseases in man.
Pavlik harness versus Frejka splint in treatment of developmental dysplasia of the hip: bicenter study.
A bicenter study was conducted to compare the results of treatment in developmental dysplasia of the hip (DDH) with Frejka splint versus Pavlik harness. Eighty-four dislocated hips were treated by the Frejka splint, and 48 dislocated hips were treated by the Pavlik harness. Failure of reduction was 10% with the Frejka splint and 12% with the Pavlik harness. Avascular necrosis (AVN, mostly type 1) was detected in 7% of Frejka patients versus 6% in Pavlik patients. The Frejka splint is simpler to use and if properly applied may be as safe as the Pavlik harness for DDH treatment.
Use of tissue expansion in clubfoot surgery.
Tissue expansion was used successfully to prepare adequate soft tissue for closure following a difficult clubfoot correction. The gradual expansion was done weekly at the outpatient clinics (average 3-4 months). The procedure proved to be useful in severe cases of clubfoot.
Excision of the posterior tibial tendon during clubfoot release.
In 50 patients (72 clubfeet), the posterior tibial tendon was excised during complete soft tissue clubfoot release. The end results after an average of 3 years were graded as follows: 55.5% excellent, 29.3% good, 8.3% fair, and 6.9% poor. Heel varus and forefoot adduction were the main causes for recurrence. Heel valgus occurred in one foot. Excision of the posterior tibial tendon is safe, does not lead to overcorrection, and may prevent further scarring created when the tendon is lengthened.
Re-do clubfoot: surgical approach and long-term results.
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Neck metaphyseal angle guidance in proximal femoral varus osteotomy.
An angle within the femoral arch is defined, and its line is described in selecting the osteotomy site and the position of the fixation device in performing a femoral varus osteotomy. This neck metaphyseal angle was measured with varying degrees of rotation on seven pediatric femurs; it was also studied on 283 randomly selected hip radiographs. The angle varied 25-40 degrees in 90% of the patients and was not age related. The angle is stable within 5 degrees as long as the landmarks, base of the great trochanter, and medial metaphysis of the femoral neck are definable (0-30 degrees of rotation).
Postpoliomyelitis syndrome problems of knee function: a review.
Postpoliomyelitis syndrome describes a ¿new¿ weakness, unrelated to any other neurological or medical disorder. It appears 10 to 15 years or more after recovery from the initial paralysis. This new weakness interferes with activities of daily living. The management of postpoliomyelitis syndrome may include orthotics, special exercises, a change in their lifestyle, or a combination of these regimens. This article is especially concerned with knee joint stabilization in various deformities that are weakened by the postpoliomyelitis syndrome.