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Biomedical subjects

H A Peterson

Publications and source records attributed to H A Peterson.

At least 19 recordsLinked to original sources
PubMed2001

Surgical treatment of Scheuermann's disease with segmental compression instrumentation.

Twenty-one patients with Scheuermann's kyphosis had surgery for progressive kyphotic deformity of 50 degrees or greater. There were six adolescents, with a mean age of 15.6 years (range, 13-17 years) and 15 young adults, with a mean age of 25.4 years (range, 18-40 years). All patients had posterior spine arthrodesis with segmental compression instrumentation. Seven patients with rigid kyphosis had combined anterior and posterior spine arthrodesis. One patient died of superior mesenteric artery syndrome. In the group of 13 patients with posterior arthrodesis only, followup was 4.5 years. The mean preoperative thoracic kyphotic curve of 68.5 degrees improved to 40 degrees at latest review, with an average loss of correction of 5.75 degrees. Junctional kyphosis occurred in two patients with a short arthrodesis: one at the cephalad end and one at the caudal end of the fused kyphotic curve. In the second group of seven patients with combined anterior and posterior arthrodesis, followup was 6 years. The mean preoperative thoracic kyphotic curve of 86.3 degrees improved to 46.4 degrees at latest review, with an average loss of correction of 4.4 degrees. Overall, there was no postoperative neurologic deficit and no pseudarthrosis. Thus, posterior arthrodesis and segmental compression instrumentation seems to be effective for correcting and stabilizing kyphotic deformity in Scheuermann's disease. Despite a long operating time, this technique provided significant correction, avoiding the development of any secondary deformity in most patients. Combined anterior and posterior spine arthrodesis is recommended for rigid, more severe kyphotic deformities.

Adolescent↗
PubMed2000

Fishtail deformity following fracture of the distal humerus in children: historical review, case presentations, discussion of etiology, and thoughts on treatment.

Fishtail deformity is an uncommon complication of distal humeral fractures in children. This article reports four cases accompanied by premature closure of a portion of the distal humeral physis with resultant deformity, length retardation, decreased elbow motion, and functional impairment. The ages of the patients at time of injury ranged from 4 years 2 months to 6 years 1 month (average 5 years 4 months). The average length of follow-up was 9 years 9 months (range, 3 years 5 months to 18 years 10 months). The cause of the arrest is multifactorial and may be due to a gap in reduction of an intracondylar fracture, avascular necrosis of the epiphysis, or central premature physeal arrest (bar formation) without a fracture gap or avascular necrosis. If identified in a young child, surgical closure of the medial and lateral portion of the physis may prevent the deformity from progressing and would not cause significant additional humeral length discrepancy.

Child↗
PubMed1997

Spinal column deformity and instability after lumbar or thoracolumbar laminectomy for intraspinal tumors in children and young adults.

STUDY DESIGN: A retrospective study about the occurrence of spinal column deformity or instability after multilevel lumbar or thoracolumbar total laminectomy for removal of benign intraspinal tumors in children and young adults. OBJECTIVES: To analyze the long-term clinical and radiographic outcome of these patients, and to specify factors that affect the occurrence of postlaminectomy spinal column deformity and instability. SUMMARY OF BACKGROUND DATA: Spinal column deformity is not uncommon after multilevel cervical or thoracic laminectomies for removal of intraspinal tumors in children. Its incidence in the lumbar and thoracolumbar spine reportedly is low. METHODS: Thirty-six consecutive patients (23 male, 13 female) underwent multilevel lumbar or thoracolumbar total laminectomy for removal of benign intraspinal tumors from 1966 to 1989. Twelve patients were aged 17 years or younger ("children and adolescents"; mean age, 11 years), and 24 were aged 18-30 years ("young adults"; mean age, 24 years). All patients had preoperative, immediate postoperative, and follow-up clinical and radiographic examinations. RESULTS: At a mean follow-up period of 14 years (range, 4-28 years), six patients (16.6%) had spinal deformity (lordosis or thoracolumbar kyphosis associated with scoliosis), and four (11%) had spondylolisthesis. Spinal column deformity occurred in 33% of children and adolescents and in 8% of young adults. Spondylolisthesis occurred in 16.6% of children and adolescents and in 8% of young adults. Three patients had fusion for spinal column deformity. Pain was present in eight patients, and other neurologic signs and symptoms were found in 18. There was an increased incidence of postoperative spinal deformity in patients who had more than two laminae removed (P < 0.01) or a facetectomy performed at the time of the initial operation (P < 0.05). There was no association between the occurrence of the deformity and sex, neurologic condition after laminectomy, or length of follow-up period. CONCLUSIONS: Spinal deformity or instability after multilevel lumbar or thoracolumbar total laminectomy is not uncommon in children and adolescents. Limiting laminae removal and facet destruction may decrease this incidence. Fusion may be required to correct post-laminectomy deformity and to stabilize the spine.

Adolescent↗
PubMed1997

A validity study of an implicit phonological awareness paradigm.

The purpose of this investigation was to examine the validity of a nonsense-word-pairs paradigm as an implicit phonological awareness task. For this task one member of each nonsense-word-pair violated the rules of consonant combination in English (e.g., /integral kib/), and the other did not (e.g., /integral rib/). The subjects were required to choose the member of the pair that contained permissible consonant sequence(s). Eighty-one normally developing first- and second-graders were given the implicit phonological awareness task, 3 explicit phonological awareness tasks, 2 reading tasks, and a multisyllabic word production task. There were significant correlations between the implicit phonological awareness task and all of the experimental tasks, with the exception of one. Additionally, the implicit phonological awareness task was sensitive to developmental differences between the first- and second-grade readers.

Child↗
PubMed1997

Metatarsal lengthening: case report and review of literature.

Shortening of one or more metatarsals may be a cause of metatarsalgia and painful toe deformity. Usually, symptoms are limited and may be successfully addressed with nonoperative treatment. Rarely, operation indicated. This report reviews the surgical techniques, results, and complications. These operations include osteotomy and one-stage distraction with bone grafting, osteotomy and one-stage distraction without bone grafting, osteotomy with gradual distraction and bone grafting, and osteotomy with gradual distraction without bone grafting.

Adolescent↗
PubMed1997

Isolated closed diaphyseal fractures of the femur in children: comparison of effectiveness and cost of several treatment methods.

The effectiveness of several treatment modalities for isolated closed femur fractures in children ages 4 through 16 years is compared based on outcome (clinical results, morbidity, and parents' satisfaction) and cost. Between 1986 and 1993, 30 patients were treated. Treatment methods included immediate hip spica cast application, distal femoral skeletal traction pin to align the fracture followed by early hip spica cast incorporating the pin (6th day), in-hospital traction, primary external fixation, and primary intramedullary nailing. Average follow up was 4.1 years. Overall results were excellent with minimal morbidity for all treatment methods. Early application of hip spica cast with or without incorporation of the distal femoral traction pin required the fewest hospital days, the shortest time to union, and had the lowest overall cost. Complications, mainly malunion and femoral length discrepancy, however, were greater. Skeletal traction resulted in the longest hospital stay and was equal in cost to external fixation and intramedullary nailing. Primary external fixation appears most applicable in patients who are unlikely to tolerate early casting and who are at increased risk of avascular necrosis with femoral nailing. Patients treated with an intramedullary nail had the fewest complications. Age, size, and gender of patient, location and type of fracture, as well as social circumstances are all significant factors in choosing the optimal method of treatment.

Adolescent↗
PubMed1996

Radial opening wedge osteotomy in Madelung's deformity.

Radiopalmar opening wedge osteotomy was used in 11 female patients (12 wrists) with Madelung's deformity who ranged in age from 9 to 31 years. Five patients met the radiographic criteria for generalized dyschondrosteosis. Clinically, there was dissatisfaction with the appearance of the wrist. The principal motion deficits were in radiocarpal extension and forearm pronosupination associated with varying degrees of discomfort with sustained activity. All had a decreased radioulnar angle, lunate subluxation shown radiographically, and various degrees of dorsal subluxation of the ulnar head. Indications for surgery were pain, limited motion, cosmetic appearance, and progressive deformity in two immature patients. Biplanar corrective opening wedge osteotomy of the radius was performed with iliac crest graft. Three patients had an added ulnar recession. Fixation was with a plate or Kirschner wire. Supplementary distracting external fixation was used in six cases. The follow-up period averaged 48 months. Pain relief in all patients was satisfactory. Range of motion and grip strength were not influenced. The radioulnar angle improved by 11 degrees, but lunate subluxation was minimally changed. Length of the forearm and bowed appearance of the forearm were improved. Reduction of the radioulnar joints was improved but remained incongruous.

Adolescent↗
PubMed1996

MR imaging of physeal bars.

PURPOSE: To determine if three-dimensional (3D) rendered and projection images derived from magnetic resonance (MR) imaging data are advantageous for the preoperative assessment of physeal bars. MATERIALS AND METHODS: Fifteen patients with suspected physeal bars were examined with MR imaging. Gradient-echo sequences were used with both two-dimensional and 3D MR imaging techniques. The 3D rendered and projection images were then derived from the MR imaging data. Patients were categorized on the basis of the effect of MR images on the decision to perform physeal bar excision. RESULTS: MR findings had either a moderate (n = 7) or a major (n = 6) effect on the surgical treatment of 13 patients (87%). They had no effect in two patients (13%) and were misleading in none. CONCLUSION: MR imaging is an excellent modality for imaging physeal bars. Imaging data can be processed to yield both 3D rendered and projection physeal maps that are particularly useful in preoperative planning.

Adolescent↗
PubMed1995

Operative hysteroscopy: American Association of Gynecologic Laparoscopists' 1993 membership survey.

The 1993 American Association of Gynecologic Laparoscopists' membership survey on operative hysteroscopy had 713 respondents reporting 14,707 procedures. Directed biopsy and endometrial ablation were the most commonly reported. The majority of operative hysteroscopies were performed for a complaint of abnormal bleeding (78%). The most frequent reported complication was uterine perforation not requiring transfusion (14.2/1000 procedures). The rates of water intoxication and pulmonary edema stayed essentially unchanged from 1991: 2/1000 in 1993 compared with 1.4/1000 in 1991. No deaths were reported this year. The consistency in rates of procedures performed and complications within the three surveys conducted in 1988, 1991, and 1993 add credibility to the data from these retrospective studies.

Biopsy↗
PubMed1994

Opening-wedge osteotomy for angular deformities of long bones in children.

Mild angular deformities associated with a mild limb-length discrepancy of long bones in children can be treated effectively with opening-wedge osteotomy with insertion of a specially prepared autogenous tricortical iliac-crest bone graft and with minimum or no internal fixation. Thirty-one osteotomies in twenty-six children satisfactorily corrected the deformities so that the angulation and length of the bone were comparable with the values on the normal, contralateral side. Physeal arrest or ipsilateral excision of a physeal bar was performed either concomitantly or at a separate operation in twenty-one of the twenty-six patients, to aid in the treatment of the limb-length discrepancy. Opening-wedge osteotomy is applicable for correction when the angular deformity is 25 degrees or less and the limb-length discrepancy is, or will be, twenty-five millimeters or less at maturity.

Adolescent↗
PubMed1993

Congenital endplate acetylcholinesterase deficiency.

Endplate acetylcholinesterase (AChE) consists of globular catalytic subunits attached to the basal lamina by a collagen-like tail. Different genes encode the catalytic subunit and the tail portion of the enzyme. Endplate AChE deficiency was reported previously in a single case (Engel et al., 1977, patient 1). We describe here our observations in four additional patients (patients 2-5). Three cases were sporadic; patients 2 and 3 were sisters. All had generalized weakness increased by exertion but ophthalmoparesis was not a constant feature. All had mild slowing of the pupillary light reflex; other dysautonomic features were absent. None benefited from anticholinesterase therapy. All patients had a decremental electromyogram response; in four of the five patients, single nerve stimuli evoked a repetitive response. Miniature endplate potential amplitude was reduced in patient 5 only. Endplate amplitudes and currents were prolonged but the open-time of the acetylcholine receptor ion channel was normal. In patients 1-4 the quantal content of the endplate potential was reduced due to a reduced number of readily releasable quanta. Quantitative electron microscopy revealed abnormally small nerve terminals, abnormal encasement of the presynaptic membrane by Schwann cells and degeneration of junctional folds and of organelles in the junctional sarcoplasm. Acetylcholinesterase was absent from all endplates of all patients by cytochemical and immunocytochemical criteria. Density gradient ultracentrifugation of muscle extracts from patients 1, 3, 4 and 5 revealed an absence of the collagen-tailed form of the enzyme in patients 1, 3 and 4 but not in patient 5. The kinetic properties of the residual AChE in muscle were normal. Erythrocyte AChE activity and Km values, determined in three patients, were also normal. Studies of the catalytic subunit gene of AChE in patients 2 and 3 revealed no abnormality in those exons that encode the domain to which the tail subunit binds. In patients 1-4 the molecular defect is likely to reside in the gene encoding the tail subunit of AChE, or in a protein necessary to assemble the catalytic and tail subunits. In patient 5, the absence of AChE from the endplate may be due to a faulty tail subunit, a defect in the basal lamina site that binds the tail subunit or failure of transport of the assembled asymmetric enzyme from the cell interior to the basal lamina. The cause of the weakness in these patients is not fully understood but possible mechanisms are discussed.

Acetylcholinesterase↗
PubMed1992

Physeal injuries of the distal humerus.

Physeal injuries of the distal humerus comprise approximately 10% of all physeal injuries. Diagnosis of these injuries at a young age before the ossification centers have ossified and become visible radiographically is difficult. Poor outcome of distal humeral physeal injuries is not uncommon and can be best prevented by knowledge of anatomy and the use of all appropriate imaging techniques. The focus of this article is to correlate anatomy at different ages with the occurrence of specific injuries.

Adult↗
PubMed1991

Premature partial physeal arrest. Diagnosis by magnetic resonance imaging in two cases.

The management of premature physeal arrest requires accurate assessment of not only the location but also the extent of the bar. Numerous imaging techniques are available to evaluate the physis. Multiplanar tomography has proven to be the most precise method. The utility of magnetic resonance imaging (MRI) of physeal bars has not been demonstrated. This article presents MRI results in two cases of physeal bars. MRI provides a means of assessing physeal bar formation with an accuracy approaching that of multiplanar tomography. In certain instances, its efficacy may exceed that of tomography, specifically when the physis cannot be properly oriented for tomographic evaluation, when more planes are desired, and when radiation exposure is thought to be excessive. With improvement of its capabilities and availability (which may also reduce cost), it may become the diagnostic imaging technique of choice.

Ankle Joint↗
PubMed1991

Radial growth plate injury in a female gymnast.

Radial growth plate injury is a cause of wrist pain in female gymnasts. The mechanism of injury and its relationship to dowel grips, now standard gymnastic equipment, are considered. An athlete's response to a treatment approach emphasizing moderation and protection is described.

Casts, Surgical↗