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Biomedical subjects

J A Ogden

Publications and source records attributed to J A Ogden.

At least 19 recordsLinked to original sources
PubMed1992

Development of vascularization in the chondroepiphysis of the rabbit.

Although numerous studies have addressed the presence of cartilage canals within developing epiphyses, the chronology of their appearance and their vascular contribution to the developing chondroepiphysis remain to be studied. We have selected a model, similar to the developing human skeletal system, in which extensive cartilage canal development precedes the subsequent secondary ossification process. In the rabbit proximal tibia, both chondroepiphyseal and vascular (cartilage canals) development were quantified from the first evidence of vessels until the formation of the secondary center of ossification. The volume of hyaline cartilage increased 25 times after intraepiphyseal vessels were initially observed. The blood supply, measured in cartilage canal volume, increased 400-fold over the same period. Three distinct cartilage canal morphologies were identifiable before the formation of the secondary center of ossification: (a) an early phase, in which the canals appeared as infoldings derived from the perichondrium; (b) a reactive phase, occurring simultaneously with chondrocyte hypertrophy and characterized by a very large increase in mesenchymal cells within the cartilage canal; and (c) a vascular phase, coincident with mineralization of the matrix, in which the familiar, unitary canal morphology was replaced by that of a vascular plexus. While matrix mineralization and the formation of bone seem dependent on critical cellular events, notably chondrocyte hypertrophy, the role that the vascular supply plays in developing sufficient biological inertia for the ossifying transition must not be underestimated.

Animals↗
PubMed1992

Manifestations of ischemic necrosis complicating developmental hip dysplasia.

Ischemic or avascular necrosis of the hip is a serious complication of the treatment of developmental hip dysplasia. The degree of ischemic insult can be classified based on an understanding of the vascularity of the proximal femur. Physeal involvement and subsequent growth disturbance, producing late deformity of the proximal femur, can compromise long-term results. Early recognition of ischemic necrosis patterns can be helpful in planning further treatment.

Femur Head Necrosis↗
PubMed1991

Radiographic changes in arthrogrypotic knees.

We evaluated the knees of 62 patients with arthrogryposis multiplex congenita radiographically. Abnormal radiographs were noted in 34. The abnormalities consisted of both congenital and chronic changes secondary to long-standing clinical deformities including patellar elongation, malposition, flattening of the femoral condyles, joint incongruity, tibial plateau irregularities, tibial and femoral fractures, fibula hypoplasia, soft-tissue thickening, valgus deformity, and dislocation. The radiographic findings were consistent with the degree of longstanding physical deformity and can be used as a guide to the severity of the condition and the need for treatment.

Arthrogryposis↗
PubMed1991

Carpal orientation from computed reference axes.

Carpal instability is usually diagnosed by abnormal two-plane radiographic angles. These angles are often unreliable. A method that eliminates interpretation of overlapping shadows and uses all of the carpal geometry should improve clinical diagnoses. The digital data from computed tomography scans can be manipulated to describe the carpal orientation in the normal wrist. The digital data from the computed tomography scans of twenty-two normal wrists were used to compute distances with and without directions between the volumetric centroids of the carpal bones. An expansion technique also extracted from the computed tomography data an orthogonal set of vectors, the principal axes. The first principal axis describes the longest dimension of each bone. The average angle produced by the first principal axes of the scaphoid and lunate was 23.6 degrees, scaphoid and capitate was 73.2 degrees, and the capitate and the lunate was 93.5 degrees. These computations represent new carpal axes and intercarpal angles that are not related to the commonly measured two-plane radiographic angles. They should prove helpful in the study of kinematics and pathomechanics in the wrist joint.

Carpal Bones↗
PubMed1991

Shark attack.

Shark attacks are rare but devastating. This case had major injuries that included an open femoral fracture, massive hemorrhage, sciatic nerve laceration, and significant skin and muscle damage. The patient required 15 operative procedures, extensive physical therapy, and orthotic assistance. A review of the literature pertaining to shark bites is included.

Animals↗
PubMed1991

Congenital lipofibromatosis associated with macrodactyly of the foot.

Congenital lipofibromatosis of the foot, a type of paracrine growth disorder, is a distinct clinical entity that must be differentiated from other causes of macrodactyly, with specific diagnostic and therapeutic considerations. Eleven skeletally immature patients with congenital lipofibromatosis and macrodactyly of the foot were studied. Diagnostic histopathologic criteria were documented. The most specific pathologic finding of congenital lipofibromatosis is an overabundance of fibrofatty tissue on the plantar aspect of the foot and involved toes. Surgical defatting or debulking procedures, ray resection, and phalangeal epiphysiodesis produced significant cosmetic improvement. Syndactylization and phalangeal resection were not as beneficial.

Adolescent↗
PubMed1990

Transphyseal linear ossific striations of the distal radius and ulna.

Radiologic and histologic analysis of transphyseal linear ossific striations of the distal ulna and radius showed that these striations consist of trabecular bone extending from the metaphysis across all zones of the physis into a small focus of fibrous and necrotic tissue within the epiphyseal cartilage. The focus appears to be a discrete area of epiphyseal ischemia with subsequent necrosis within and around the vasculature of a cartilage canal and probably represents a microscopic response to antecedent trauma that was insufficient to cause macrofailure (fracture) of the physis. The striations did not continue into the epiphyseal ossification center. The consequence is partial osseous bridging across the physis. This bridging is unlikely to cause significant growth damage, since in most cases it does not appear to extend farther into the secondary ossification center.

Child↗
PubMed1990

Fractures of the calcaneal apophysis.

Eleven patients with 12 open or closed fractures of the calcaneal apophysis were reviewed. The patterns of fracture varied, although all could be classified by a scheme similar to that used for physeal injuries in the long bones. Open injuries involved young children and were associated with subsequent maldevelopment of the posterior (nonarticular) portion of the calcaneus due to growth mechanism damage. The other susceptible age group, adolescence, had two patients with slipped calcaneal apophysis (type 1 injury), similar to slipped capital femoral epiphysis, and three patients with a splitting fracture through the apophysis and physis into the main part of the calcaneus (type 4 injury). Microscopic physeal injury was also observed in the calcaneus of a fatally injured boy.

Adolescent↗
PubMed1990

Magnetic resonance imaging evaluation of congenital dislocation of the hips.

Magnetic resonance (MR) images were obtained preoperatively and postoperatively for 12 pediatric patients with congenital dislocation of the hip (CDH). The images were compared with arthrograms and computed tomography scans. The MR images were more accurate in defining soft-tissue anatomy, hip position, and obstructive factors to relocation. MR imaging is an efficient diagnostic tool in CDH.

Arthrography↗
PubMed1990

Wrist and hand skeletal injuries in children.

When accidents occur, the hand is the part of the body most often thrust out to lessen the consequences, resulting in a wide array of combinations of soft-tissue and chondro-osseous injuries. Pediatric wrist and hand skeletal injuries discussed in this article include growth mechanism injury, fractures and dislocations, nailbed injuries, fingertip injuries, burns, and frostbite.

Child↗
PubMed1989

Visuospatial and other "right-hemispheric" functions after long recovery periods in left-hemispherectomized subjects.

Two subjects who had infantile brain damage and left hemispherectomies at the ages of 17 and 18 yr are assessed after 28 and 16 yr recovery periods. Both have intact language and verbal memory abilities. However, on functions normally mediated predominantly by the right hemisphere, including nonverbal memory, higher cognitive visuospatial skills, and complex extrapersonal orientation ability, they are severely impaired. Simple visuospatial perceptual and orientation abilities, emotional expression, and face recognition, also "right-hemispheric" functions, are normal. It is postulated that the right hemisphere, if isolated in infancy, has the potential to take over most cognitive functions. The pattern of intact and impaired abilities shown by these subjects allows a hierarchy of functionally important abilities to be constructed. The functions mediated by the solitary right hemisphere are those most essential for independent survival, and functions that are not represented are those least required.

Adult↗
PubMed1989

The painful accessory navicular: a clinical and histopathological study.

Twenty-two skeletally immature patients with 39 accessory tarsal navicular bones were seen over a 4-yr period. Twenty-five of the feet with accessory naviculars were symptomatic and, after failure of conservative treatment, were treated by excision of the accessory bone, the synchondrosis, and the prominent portion of the main navicular ossification process. No attempt was made to reroute the posterior tibial tendon. All 25 operative feet were completely relieved of the preoperative pain. The external oblique view was found to be the best radiographic view to demonstrate the accessory navicular. Histological findings in the surgical specimens included areas of micro-fracture through the cartilaginous synchondrosis, acute and chronic inflammation, and cellular proliferation indicative of attempted repair. These changes are consistent with the theory that chronic chondro-osseous tensile failure can occur in this condition and is responsible for the clinical findings.

Adolescent↗
PubMed1989

Chondro-osseous growth abnormalities after meningococcemia. A clinical and histopathological study.

The cases of nine children who survived the acute stage of meningococcal septicemia and secondary disseminated intravascular coagulation were reviewed. All of the children had major orthopaedic problems as a result of the acute disease. Detailed histological studies were performed on specimens of bone and cartilage, obtained when these patients had either acute amputation for gangrene or subsequent revision for a chondro-osseous deformity. In the specimens that were obtained from the children who had acute gangrene, the histological changes included small-vessel thrombi, osteonecrosis, subperiosteal new-bone formation, cortical disruption, cellular disorganization in the physis, and medullary inflammation. These findings were compatible with a combination of inflammation (acute osteomyelitis) and ischemia. In the specimens that were obtained during revision of the amputation, three years or more after the initial infectious or ischemic process, the clinically relevant findings involved the epiphyses and physes. The growth plates showed variable permanent ischemic damage. Bone bridges connecting the epiphysis and metaphysis were observed in various stages of formation, including several early bridges with involvement of only the physis and metaphysis. Endosteal and cortical bone, in contrast, showed complete recovery with no evidence of permanent ischemic damage. We concluded that children who survive meningococcal septicemia are at high risk for complex orthopaedic problems, both acute and chronic. The disseminated intravascular coagulation and focal infections of the acute phase are primarily responsible for the vascular injuries to the growing chondro-osseous tissues. Ischemic changes also selectively involve the physeal circulation, but may take several years to adversely affect longitudinal and transverse growth of bone.

Adolescent↗
PubMed1988

Language and memory functions after long recovery periods in left-hemispherectomized subjects.

Two subjects who had infantile brain damage and left hemispherectomies at the ages of 17 and 18 yr are assessed after 28 and 16 yr recovery periods. Deficits on the comprehension of passive-negative sentences disappeared when the subjects read rather than heard the sentences, and performances were normal on the Token and Reporter's Tests, and tests of verbal memory. These results suggest that if damage to the left hemisphere occurs early in life and there is a long recovery period, the right hemisphere can mediate verbal memory and the more subtle aspects of language. This provides support for the hypothesis that the two hemispheres are equipotential for language and verbal memory.

Adult↗
PubMed1988

Dichotic listening in commissurotomized and hemispherectomized subjects.

Three commissurotomized and two left-hemispherectomized subjects were tested on spoken report of sequences of three dichotic pairs of digits. With instruction to report only one digit from each pair, there was an overall advantage to the ear contralateral to the hemisphere mediating speech, but report of ipsilateral-ear digits ranged from 40 to 100%. In commissurotomized subjects, the more extreme ipsilateral suppression under instructions to report all digits may be due to failure to gain access to unattended information stored in the right hemisphere, rather than to suppression of the ipsilateral pathway. However one commissurotmized patient did appear to have access to right-hemisphere items, the result either of subcortical transfer or of external cross-cueing. The hemispherectomized subjects seemed able to store both attended and unattended information in the same hemisphere.

Adult↗
PubMed1988

Lawn-mower injuries in children.

The power lawn mower is capable of inflicting serious injury, particularly to the pediatric population. A total of 27 patients who had sustained lawn-mower injuries were reviewed to identify those factors responsible for power-mower accidents and to determine an effective treatment regimen for these patients. The injuries included amputations in 19, major lacerations in 34, and fractures in 23 extremities. Aggressive treatment of both the soft tissue and bony injuries was necessary. Fractures were treated with either open reduction and internal fixation or external fixation, as appropriate, and early soft tissue coverage. The results were satisfactory in the majority of patients, but often required multiple surgical procedures over a number of years. The incidence of these injuries can be reduced by educating the public about the potential dangers of these machines, and by encouraging the use of proper safety procedures.

Accidents, Home↗