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Biomedical subjects

S E Koop

Publications and source records attributed to S E Koop.

6 recordsLinked to original sources

A nondimensional normalization scheme for oxygen utilization data.

The total oxygen required for gait (gross utilization) is a widely used indicator of locomotor efficiency. The standard scheme of mass normalization (dividing gross utilization by mass) is intended to eliminate confounding effects that arise from variations in age and size. Despite its prevalence, mass normalization has been shown to be inadequate, as the normalized quantity retains a marked dependence on clinically relevant factors. The current study proposes a new scheme for normalizing oxygen utilization data. The new scheme, called net-nondimensional normalization, is based on the use of net oxygen utilization (gross-rest) and nondimensional gait variables. Measures of statistical significance are employed to demonstrate that net nondimensional normalization is superior to mass normalization. Net nondimensional oxygen utilization is shown to be largely independent of the relevant physiological and anatomical factors, and is therefore well suited for studies where an independent measure of gait efficiency is needed.

Adolescent↗

[Treatment of deformities of the locomotor system in hemiplegia].

In spastic hemiplegia mainly one side of the body is affected. In both the upper and the lower extremity the distal parts (hand and foot) are more severely involved than the proximal region. In cases of minor involvement the goal of treatment in the upper extremity is to achieve functional improvement by means of splinting and surgery. In cases of severe alterations cosmetic improvement without much functional gain is all that can be expected. Gait analysis has demonstrated that there are four basic patterns that can be related to the severity of involvement. In type I muscle imbalance exists without a contracture. In type II there is contracture of the muscles of the posterior compartment of the calf. In type III, in addition to the changes around the ankle joint, contractures around the knee are present, and in type IV also hip problems. Functional improvement can be achieved by means of splinting and surgery in all types. Basic principles of treatment have developed as a result of the application of gait analysis and dynamic electromyography. Specific examples of such treatment principles have recently been presented by Gage.

Child↗

Infantile and juvenile idiopathic scoliosis.

Infantile and juvenile idiopathic scoliosis have distinct presentations and natural histories when compared with adolescent idiopathic scoliosis. In addition to age at onset, differences exist in associated anomalies, and frequency and rate of deformity progression. Treatment methods differ from adolescent deformities, and deserve separate discussion.

Age Factors↗

The surgical treatment of instability of the upper part of the cervical spine in children and adolescents.

In a retrospective review of the cases of thirteen skeletally immature children and adolescents (four to eighteen years old) with instability of the upper part of the cervical spine (occiput to fifth cervical vertebra), we determined the efficacy of posterior arthrodesis and halo-cast immobilization in the management of this condition. The patients were divided into two groups: those with congenital vertebral anomalies alone (fusion or structural defects, or both) and those with cervical anomalies and systemic disorders (dwarfism, juvenile rheumatoid arthritis, Down syndrome, and cerebral palsy). Two patterns of instability were found: instabilities at intervertebral joints adjacent to vertebral fusions, and instabilities located in vertebral defects. For all patients treatment included a posterior arthrodesis with external immobilization by a halo cast, and in two patients internal fixation with wire was also used. Solid arthrodesis was obtained in the twelve patients who were treated with autogenous grafts (iliac cancellous bone in eleven and rib bone in one), and a non-union developed in a child who was treated with bank-bone rib segments. Posterior cervical arthrodesis with wire fixation carries some risk of neural injury and often is not applicable in children with anomalous vertebrae. Spine fusion using delicate exposure, decortication using an air-drill, and placement of autogenous cancellous iliac grafts with external immobilization by a halo cast minimizes the risk of neural damage and is a reliable way to obtain a solid arthrodesis.

Adolescent↗

Determination of "normal" thoracic kyphosis: a roentgenographic study of 121 "normal" children.

The purpose of this prospective study was to determine the range of "normalcy" in the radiologic measurement of thoracic kyphosis in children by using a standardized position and full-length radiograph in 121 normal children. Using +/- two standard deviations from the mean as the definition of "normal," a range of 20 degrees - 50 degrees was determined. There was no difference between the various age subgroups or between genders.

Adolescent↗

Spinal instrumentation without fusion for progressive scoliosis in young children.

Between 1973 and 1993, a heterogeneous group of 67 children with progressive scoliosis entered a program of incremental-distraction spinal instrumentation without fusion supplemented by full-time external orthotic support. Over the course of treatment, curve magnitude improved from an average of 67 degrees at initial instrumentation to 47 degrees at definitive fusion. For all patients, curve response tended to decline with consecutive procedures. The measured growth of the instrumented but unfused spinal segments averaged 3.1 cm over a mean treatment period of 3.1 years. The results of our study suggest that spinal instrumentation without fusion can control progressive scoliosis in a majority of children while allowing normalized growth of instrumented spinal segments. The mean duration of treatment and ultimate gain in spinal length are constrained by progressive structural changes that alter curve response to incremental distraction. Despite these limitations, spinal instrumentation without fusion may provide a reasonable management alternative when individualized among these difficult patients.

Adolescent↗