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[Multifocal osteonecrosis in children and adolescents after polychemotherapy].

Adequate treatment protocols provide excellent results in management of lymphoma, leukemia and other malignancies in children. With improved survival rates, therapy related sequaela like osteonecrosis (avascular necrosis of bone, AVN) have become a matter of increasing concern. From 1982 to 1992 121 patients were treated for acute lymphocytic leukemia, acute myelocytic leukemia, Hodgkin's Lymphoma, Non-Hodgkin's Lymphoma and Langerhanscell-histiocytosis. All patients were treated with multiagent regimes that included low-dose steroid therapy. 23 patients died, but 64 patients could be evaluated 4 to 14 years after chemotherapy. If the patient complained of bone or joint pain or other clinical findings were suspicious for bony lesions, radiological evaluation was made to get prove of AVN. Six out of 64 patients developed AVN at 17 different sites. Four patients had multifocal AVN. The interval between induction chemotherapy and onset of symptoms was at average 12 months. The average cumulative steroid dosage was 4.25 g. AVN did not relate to sex, diagnosis or a single agent, but did relate to age. There were no cases of AVN in patients younger than 10 years of age. Four patients required surgical intervention. AVN after polychemotherapy was only seen in patients over the age of 10 years. AVN developed at an average of 12 months after induction chemotherapy during the maintenance dose phase. Therefore careful clinical monitoring of patients receiving polychemotherapy is indicated and if indicated radiological evaluation for early detection of AVN to prevent further morbidity is necessary.

Adolescent↗

PubMedDate not supplied

[Remodeling of the acetabulum after experimental hip joint dislocation--an animal experiment study of the rabbit].

PURPOSE: Little is known about the remodeling potential of the acetabulum after dislocation and relocation of the hip joint. Most clinical data rely on radiographic measurements in a clinical setting, with only few singular reports on histologic changes at the time of surgery. This study was undertaken to examine the remodeling potential of the rabbit acetabulum after different length of hip dislocation and to gain insight into the histology of the remodeling process involved. METHOD: The right knee joint was immobilized in 28 matched New Zealand white rabbits, causing dislocation of the associated hip joint. Assessment of the joint status was made by serial X-rays in a reproducible standardized way, allowing measurement of the Acetabular Index (AI). The untreated left hip joints served as controls in the histologic sections and also allowed to develop an age matched scale of normal acetabular development for radiographic assessment. Dislocation was unsuccessful in 2 rabbits, 9 animals were sacrificed with the joint dislocated, and in 13 animals a closed reduction was performed and maintained in a Petrie type position for 10 days. Reduction was unsuccessful in 4 cases. The reduced group was sacrificed after 4 to 12 weeks, the point of harvesting being determined by no further change in the serial standardized radiographic measurements of the AI. All surgical procedures were done under the supervision of a veterinary surgeon and followed an approved protocol. RESULTS: In the time observed, the normal values of the Acetabular Index drop from 30 degrees to 20 degrees over a time of 3 months. In animals with a dislocated hip the AI increased to 40 degrees, which was completely reversible and reached normal values in 4 weeks, if reposition was done at this time (group A). Later reposition did improve the AI, but compared to normal age matched values, the AI remained elevated (> 30 degrees), demonstrating a residual dysplasia (group B). The histologic sections of the control left joints showed normal hyaline cartilage with physiologic vertical stacking of the cartilage zones. In the dislocated group the vertical stacking was lost, with chondrocytes demonstrating a fibro-cartilaginous metaplasia. There was hypocellularity with loss of nuclear staining. These changes were completely reversed in the group A, but remained in group B. CONCLUSIONS: This study demonstrates that an early reduction will not only allow for a normalisation of the radiographic values, but that the histologic changes as they develop during dislocation can completely be reversed. Long standing dislocation will lead to a permanent tissue metaplasia similar to the one seen in compression testing of joint cartilage, therefore loosing the potential for remodeling. Similar processes may occur in the human situation and the findings here underline the necessity for early reduction to allow for a complete remodeling of the hip joint.

Acetabulum↗

PubMedDate not supplied

Functional MRI of language-related activation in left frontal schizencephaly.

Brain activation associated with covert verb generation was studied in a right-handed patient with an asymptomatic left frontal schizencephaly by functional magnetic resonance imaging. Activation of the dysplastic neuronal tissue lining the cleft and the adjacent cortex was found, indicating participation of the malformed region in physiologic cerebral functions. This finding may have clinical impact in patients with medically intractable seizures due to malformations of the cortical development prior to epilepsy surgery.

Adult↗