Biomedical subjects

J G Jarvis

Publications and source records attributed to J G Jarvis.

9 recordsLinked to original sources

PubMed2001

The complex triplane fracture: ipsilateral tibial shaft and distal triplane fracture.

BACKGROUND: The complex triplane fracture (ipsilateral tibial shaft and distal tibial triplane fracture) is a rare combination. It has not previously been described in the literature. This combination can be easily overlooked and has the potential for serious sequelae if it is missed. METHODS: Six patients, having sustained this combined injury, were reviewed at a tertiary children's hospital. Clinical assessment, radiographs, computed tomographic scans, bone age, and scanogram assessment of leg length at maturity were completed. RESULTS: Average age at injury was 14 years. Tibial fractures were midshaft or short oblique. There were 3 three-part and 3 two-part intra-articular distal tibial triplane fractures. Diagnosis of the distal triplane fracture was delayed in two cases. Treatment involved application of a long leg cast. No patients required open reduction. At follow-up (average, 22 months), all patients were asymptomatic. All fractures were well healed and there was no evidence of joint incongruity, or angular or rotational deformity. Leg length discrepancy averaged 6.8 mm. CONCLUSION: A high index of suspicion should be maintained to avoid missing this rare combination, as it has the potential for long-term sequelae.

Adolescent↗

PubMed1998

Histomorphic analysis of the development of the pars interarticularis and its association with isthmic spondylolysis.

STUDY DESIGN: Descriptive study analyzing the histologic development of human fetal lumbar spine pars interarticularis. OBJECTIVES: To delineate the histologic development of the fetal pars interarticularis and correlate the development of the pars with isthmic spondylolysis. SUMMARY OF BACKGROUND DATA: Isthmic spondylolysis is present in 5% to 6% of the population. The incidence at birth is zero but rises sharply to 5% at age 4 to 5 years. The origin of the lesion is unknown; however, the current theory states that isthmic spondylolysis results from a fatigue fracture through a congenitally weak pars interarticularis. No study exists investigating the histologic development of the pars. METHODS: Microscopic examination of lumbar spines of human fetuses aged 8-20 weeks' gestation was performed. Specimens were dissected en bloc, decalcified, embedded in paraffin wax, sectioned and fixed on glass slides, and stained. RESULTS: The pars begins to ossify at 12 to 13 weeks' gestation by endochondral ossification. The ossification center originates in the region of the pars in lower lumbar vertebrae, resulting in uneven distribution of trabeculation and cortication in this region. The ossification center arises at the end of the pedicle in upper lumbar segments giving rise to uniform trabeculation through the pars. CONCLUSIONS: Uneven distribution of isthmic ossification results in formation of a potential stress riser in the region of the pars in lower lumbar vertebrae, which could be susceptible to fatigue fracture.

Fetus↗

PubMed1998

Pathogenesis of soft-tissue contracture in club foot.

We investigated the pathogenesis of soft-tissue contracture in club foot, using immunohistochemistry to study 41 biopsy specimens and 12 normal deltoid ligaments from cadavers. Five biopsy specimens were studied by electron microscopy (EM) to determine the presence of myofibroblasts. All 41 specimens of club foot stained positively for vimentin as against only one of the 12 control specimens. By contrast, there was no difference in staining for desmin or alpha-smooth muscle actin. EM showed some variability in the appearance of ligamentous cells. Most contained bundles of microfilaments in the cytoplasm and many had abundant pinocytotic vesicles, but no basal lamina or plasmalemmal attachment plaques. Cells of the medial ligamentous tissue in patients with club foot contain vimentin and others have myofibroblastic characteristics. Both features may contribute to recurrence after soft-tissue release.

Actin Cytoskeleton↗

PubMed1997

[Not Available].

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Journal Article↗

PubMed1996

Adolescent idiopathic scoliosis. Correction of vertebral rotation with use of Wisconsin segmental spinal instrumentation.

We retrospectively reviewed the results of use of Wisconsin segmental spinal instrumentation in twenty-four patients who had adolescent idiopathic scoliosis. Our purpose was to determine whether there had been any correction of the rotational component. The mean age at the time of the operation was thirteen years and eight months (range, eleven to seventeen years). Computerized tomography was used to measure the degree of vertebral rotation relative to the midline of the body and relative to the mid-sagittal plane in thirty curves that had been treated with instrumentation and in fifteen that had not. According to the criteria of King et al., five patients had a type-I curve; fourteen, a type-II curve; four, a type-III curve; and one, a type-V curve. The mean correction in the coronal plane was 23 degrees (43 per cent; range, 20 to 69 per cent) for the curves that had been treated with instrumentation and 15 degrees (35 per cent; range, 11 to 77 per cent) for those that had not. The mean derotation of the apical vertebra, in relation to the midline of the body, in twenty-two curves that had been treated with instrumentation and that had had a mean initial rotation of 26 degrees (range, 8 to 53 degrees) was 6 degrees (range, 1 to 29 degrees). For seven curves, with a mean initial rotation of 25 degrees (range, 21 to 35 degrees), rotation increased a mean of 3 degrees (range, 1 to 7 degrees) after instrumentation. The rotation of the apical vertebra did not change in one curve treated with instrumentation. Derotation was seen in twelve of the fifteen curves that had not been treated with instrumentation.

Adolescent↗

PubMed1988

The posterior tether in scoliosis.

The hypothesis that a localized lordosis, or tethering of the posterior elements of the spine, is the primary cause of the vertebral rotation in idiopathic scoliosis was investigated in anatomic specimens of human and calf spinal columns. The specimens were axially loaded with and without a posterior tether created using Zielke instrumentation. Lateral deflection and axial rotation were monitored roentgenographically. The vertebrae of tethered spines showed increased rotation in the direction associated with idiopathic scoliosis. The spinous processes moved toward the concavity at the apex of the induced lateral curve. Conversely, untethered spines either exhibited little rotation or rotated in the opposite direction; the spinous processes moved toward the convexity of the curve. Rotations toward the convexity occur in rotational kyphosis. Thus the hypothesis that idiopathic scoliosis is a rotational lordosis is substantiated; the characteristic rotation can be explained with the aid of a geometric model.

Animals↗

PubMed1984

The pediatric T-supracondylar fracture.

T-supracondylar fractures of the humerus occur rarely in children compared with the adult variety. Sixteen such fractures treated at the Children's Hospital of Eastern Ontario between 1975 and 1983 are described. There were nine male and seven female patients, 7-17 years old. All fractures were displaced, two were open, and one patient had an associated radial nerve palsy. All cases were managed by open reduction, internal fixation, and early mobilization. Follow-up revealed no cases of functional disability despite significant loss of motion in two patients. The conservative approach should be abandoned in these intraarticular injuries, and good operative results can be anticipated.

Adolescent↗

PubMedDate not supplied

Pseudomonas osteochondritis complicating puncture wounds in children.

Pseudomonas osteochondritis is an uncommon complication of puncture wounds. It can have a particularly devastating affect in the growing child, often resulting in significant permanent sequelae. To assess the current approach to diagnosis and treatment of this condition in children, 15 such cases seen at the Children's Hospital of Eastern Ontario between 1975 and 1991 were studied retrospectively. Case presentations were similar, with delayed onset of localized pain, swelling, and elevated erythrocyte sedimentation rate following a puncture wound. All patients had previously received oral antibiotics. Initial radiographic changes were rare. All patients were treated with i.v. antibiotics: although most required surgical debridement. Complications including recurrence, chronic pain, and deformities required sequestrectomies, angular osteotomies, and leg-lengthening procedures. A high index of suspicion, coupled with aggressive medical and surgical treatment, is required for a satisfactory outcome.

Anti-Bacterial Agents↗

PubMedDate not supplied

Anterior cruciate ligament tears in children: an analysis of operative versus nonoperative treatment.

A 12-year retrospective analysis of 42 children with arthroscopically confirmed anterior cruciate ligament disruption was undertaken to determine (a) the subjective efficacy of treatment, (b) the clinical and biomechanical results of operative and nonoperative management, and (c) the most appropriate long-term outcome measurements. Patients were followed up for a mean of 5.3 years from the time of initial treatment and were between the ages of 5 and 17 years (mean, 14.4) at the time of treatment. The children were treated nonoperatively by primary ligament repair or by intraarticular anterior cruciate ligament reconstruction. In the child, a complete tear of the anterior cruciate ligament was best managed by intraarticular surgical reconstruction. This was confirmed by clinical examination (p < 0.01), by a composite knee score involving a clinical examination and patient questionnaire (p < 0.0005), and by testing with the KT-1000 arthrometer. No significant differences in outcome could be attributed to the patient age or the maturity of the growth plates. In the active child, anterior cruciate reconstruction for complete tears resulted in a more stable and functional knee.

Adolescent↗