Archives of orthopaedic and trauma surgery
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Arch Orthop Trauma Surg · Nov 2001
Case ReportsPeriosteal Ewing's sarcoma: radiological imaging and histological features.
Periosteal Ewing's sarcoma is very rare. In this report, we describe three cases of periosteal Ewing's sarcoma, illustrating the principal clinical, radiographic, and histologic features. The patients were aged 15, 16, and 20 years old, with an average of 17 years. ⋯ The unusual site of Ewing's sarcoma was clearly visualized by computed tomography (CT) and magnetic resonance imaging (MRI) and confirmed by histological examination. Chemotherapy and/or irradiation was employed before and after wide excision. The patients have survived an average of 6 years after the primary surgery.
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Freeze-dried human bone allograft is used clinically as an adjunct to autologous bone graft. When freeze-dried human bone allograft is demineralized, the allograft is osteoinductive, since it causes bone to form heterotopically. Both types of allograft are also used alone, such as in spinal fusions, critical size defects, and periodontal therapy. ⋯ In the demineralized, freeze-dried bone from donors younger than 42 years of age, the bone induction score and new bone area were significantly higher than in the other batches of bone graft, and the area of residual particles was reduced. Both demineralized and nondemineralized bone graft from patients older than 70 years of age were encapsulated in dense, fibrous connective tissue. These results may help explain the observed differences in clinical outcome when demineralized, freeze-dried bone graft or nondemineralized, freeze-dried bone graft from different donors is used in bone regeneration applications.
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Arch Orthop Trauma Surg · Nov 2001
Light and electron microscopic study of stress-shielding effects on rat patellar tendon.
In this second part of our study, the histomorphologic changes occurring in the patellar tendon (PT) of rats after sole stress-shielding were evaluated. In seven adult albino rats, both PTs were exposed by straight skin incision and then stress-shielded on one side by a cerclage, while the contralateral PT served as the sham-operated control. One animal died after the operation and was used as a negative control. ⋯ Ultrastructural evaluation and morphometry revealed a predominance of large diameter (peak between 180 and 260 nm) collagen fibrils in the sham-operated controls, while in the stress-shielded tendons the number of apparently new, small-diameter (peak between 40 and 60 nm) collagen fibrils increased (up to 77% per cross-sectional field of view). The difference in peak diameters was statistically significant (p < 0.0005). This rat model demonstrated that sole stress-shielding not only causes biomechanical alterations, but also intense tissue remodelling and significant morphological changes in the collagen fibrils in the patellar tendon, comparable to so-called 'ligamentization' in experimental and clinical patellar tendon grafts for anterior cruciate ligament reconstruction.
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Arch Orthop Trauma Surg · Nov 2001
A minimally invasive percutaneous technique of intramedullary nail insertion in an animal model of fracture healing.
Previous animal models of fracture repair have been shown to be reproducible but are often time-inefficient. We present a minimally invasive percutaneous technique for retrograde insertion of intramedullary pins in a model of rat femoral fracture healing. Forty Sprague-Dawley rats were divided into 3 groups: no fracture (n = 6), no fracture but pinned (n = 6), and fractured and pinned (n = 24). ⋯ The mean fluoroscopic time for the last 15 procedures was 4.2 s (standard deviation 1.2 s). No patellar tendon ruptures or bleeding complications were seen in the postoperative period. The course of fracture healing was not altered by this new percutaneous technique of pin insertion.