Primary Spinal Epidural/Extramedullary Ewing Sarcoma in Young Female Patients.

Primary spinal epidural/extramedullary ewing sarcoma (ES) is a rare extraosseous lesion. Extraosseous ES has a similar demographic as osseous ES, primarily affecting adolescents and young adults and male propensity. Reported 5-year survival is 0% to 37.5% for spinal extraosseous ES. METHODS: Two girls, 19 and 14 months old, presented with progressive lower extremity paraplegia and incontinence. Both had a compressive epidural/extramedullary mass without metastases and underwent decompression with multilevel laminectomy and tumor excision. Primary spinal epidural/extramedullary ES was diagnosed. RESULTS: Case 1 received 34 weeks of chemotherapy and radiation therapy, and case 2 received 14 cycles of chemotherapy and autologous stem cell rescue without radiation therapy. After more than 5- and 8-year follow-up, case 1 and case 2 are walking and disease-free, respectively. CONCLUSION: These cases are the youngest presentation reported for primary spinal epidural/extramedullary ES and suggest that toddlers have a better prognosis for survival than older children and adolescents.

Biomechanical Comparison of 2 Methods of Intramedullary K-Wire Fixation of Transverse Metacarpal Shaft Fractures.

PURPOSE: To determine the relative importance of intramedullary wire (IMW) diameter and IMW number in conferring stability to a metacarpal fracture fixation construct. Our research hypothesis was that the stiffness of IMW fixation for metacarpal shaft fractures using a single 1.6-mm-diameter (0.062-in) wire would be greater than three 0.8-mm-diameter (0.031-in) wires. METHODS: Our study compared the biomechanical stiffness between one 1.6-mm K-wire and three 0.8-mm K-wires in a composite, fourth-generation, biomechanical metacarpal construct under cantilever testing to treat transverse metacarpal shaft fractures. Six composite bone-wire constructs were tested in each group using constant-rate, nondestructive testing. Stiffness (load/displacement) was measured for each construct. RESULTS: All constructs demonstrated a linear load-displacement relationship. Wires were all tested in their elastic zone. The mean stiffness of the 1-wire construct was 3.20 N/mm and the mean stiffness of the 3-wire construct was 0.76 N/mm. These differences were statistically significant with a large effect size. CONCLUSIONS: The stiffness of IMW fixation for metacarpal shaft fractures using a single 1.6-mm-diameter wire was significantly greater than using three 0.8-mm-diameter wires. CLINICAL RELEVANCE: When IMW fixation is clinically indicated for the treatment of metacarpal fractures, the increased stiffness of a single large-diameter construct provides more stability in the plane of finger flexion-extension.