A retrospective analysis of 18 patients with 19 acute tibial tubercle avulsion fractures was performed. Mean age at injury was 13 years 8 months. Mean follow-up time was 2 years 8 months. A group of four preadolescent patients ages 9 to 12 years at injury was identified. Participation in athletics, particularly basketball, resulted in 77% of fractures. There were one type IA, three type IB, two type IIA, six type IIB, two type IIIA, four type IIIB, and one type IV fractures. Fifteen fractures were treated with open reduction and internal fixation and four by closed reduction and cylinder cast immobilization. Three cases (15.7%) of extensor mechanism disruption were noted, two patellar tendon avulsions and one quadriceps avulsion. Final outcome was good in all patients regardless of fracture type or treatment. There were no complications.
Gross and histologic examinations of 15 normal cadaver and 15 surgical posterior tibial tendons from patients with posterior tibial tendon insufficiency were performed. All surgical specimens were abnormal with enlargement distal to the medial malleolus and a dull white appearance. At histologic examination, 12 of 15 cadaver tendons displayed normal tendon structure characterized by linear orientation of collagen bundles, normal fibroblast cellularity, low vascular density, and insertional chondroid metaplasia. The surgical specimens displayed a degenerative tendinosis characterized by increased mucin content, fibroblast hypercellularity, chondroid metaplasia, and neovascularization. This resulted in marked disruption of the linear orientation of the collagen bundles.
Previous studies have demonstrated that ligand-induced down-regulation of the LH/hCG receptor in rat corpus luteum results in a loss of ligand-binding activity and a parallel decline in steady state levels of receptor mRNA. The purpose of the present study was to determine whether this loss of receptor mRNA during receptor down-regulation is due to inhibition of transcription or increased degradation of the receptor mRNA. To differentiate between these two possibilities, nuclear run-off assays were performed to study transcription rates of nuclei isolated from control and hCG down-regulated rat ovaries. A 750-mer LH/hCG receptor cDNA probe, spanning the carboxy-terminal region of the peptide and the 3'-untranslated region of the receptor cDNA, was constructed by polymerase chain reaction. RNA transcripts were synthesized from existing nuclear RNA from control and down-regulated nuclei and hybridized to the receptor cDNA probe immobilized on nylon membranes and subjected to autoradiography. Hybridization to actin cDNA was also run alongside as a control. The results of run-off transcription analysis indicated that during down-regulation, the transcription rates of LH/hCG receptor mRNA are not decreased compared to those in saline-treated controls. Although no decrease in the transcription rates of the receptor mRNA was seen in the down-regulated state, the steady state levels of the receptor mRNA showed a decline when assayed by either solution hybridization or Northern blot analysis. Furthermore, hCG induced down-regulation appears to increase the transcriptional activity of the nuclei. Estimates of steady state LH/hCG receptor mRNA turnover rates indicate that the half-life of the message in down-regulated ovaries is markedly reduced compared to that in the control. It is concluded that the loss of steady state LH/hCG receptor mRNA is not due to a decrease in transcription, but probably represents an increased degradation of the receptor mRNA.
Less than 10% of chondrosarcomas occur in children. In addition, as little as 0.5% of low-grade chondrosarcomas arise secondarily from benign chondroid lesions. The presence of focal pain is often used to crudely distinguish a chondrosarcoma (which is usually managed with wide surgical excision), from a benign chondroid lesion (which can be followed by clinical exams and imaging surveillance). Given the difficulty of localizing pain in the pediatric population, initial radiology findings and short-interval follow-up, both imaging and clinical, are critical to accurately differentiate a chondrosarcoma from a benign chondroid lesion. To our knowledge, no case in the literature discusses a chondrosarcoma possibly arising secondarily from an enchondroma in a pediatric patient. We present a clinicopathologic and radiology review of conventional chondrosarcomas. We also attempt to further the understanding of how to manage a chondroid lesion in the pediatric patient with only vague or bilateral complaints of pain.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.