Nonunion of fractures about the femoral neck and intertrochanteric hip regions is uncommon. Patients who develop nonunions of these fractures typically exhibit marked pain and disability, thereby presenting a treatment challenge to the orthopaedic surgeon. Factors that guide the choice of salvage treatment include the anatomic site of the nonunion, the quality of the remaining proximal bone and articular surface, and patient factors (such as age and activity level). In the younger patients with a well-preserved hip joint, treatment typically involves revision internal fixation with or without osteotomy or bone grafting. However, in older patients, it is more common to encounter poor remaining proximal bone stock or a badly damaged hip joint from hardware cutout. As such, conversion to hip arthroplasty is intended to help effectively restore function and relieve pain. With respect to salvage procedures for the femoral head, the major challenges in decision making include the choice of both internal fixation device and accurate preoperative planning. The challenges involved in planning to convert to hip arthroplasty include the need for acetabular resurfacing, selecting the femoral implant, and managing discontinuity of the greater trochanter. Furthermore, there are additional technical challenges that may be encountered, such as broken hardware, deformity, and femoral bone defects. Overall, salvage of nonunions of femoral neck and intertrochanteric hip fractures in properly selected patients can provide patients with good to excellent results.
The patient access time interval is significantly long and represents a substantial component of the total EMS response time interval, especially among ambulance calls originating three or more floors above ground. A number of barriers appear to contribute to delayed paramedic access.
Constitutive hedgehog signaling has been implicated in the tumorigenesis of cartilaginous neoplasia; however, a common mutational mechanism remains unknown. Some tumors exhibiting hedgehog pathway activation such as basal cell cancer frequently harbor PATCHED-ONE (PTCH-1) or SMOOTHENED (SMO) gene mutations. We therefore asked whether mutations of the hedgehog receptor genes PTCH-1 or SMO occur in cartilage tumors. Singlestrand conformation polymorphism (SSCP) analysis with subsequent manual sequencing was performed to detect alterations of PTCH-1 and SMO in 46 cartilage tumors. SSCP detected five shifts in the PTCH-1 gene and two shifts in SMO. Direct DNA sequencing revealed the five shifts in PTCH-1 were caused by silent nucleotide alterations. The two SMO shifts were the result of the same missense mutation (783G>A) and occurred in one dedifferentiated chondrosarcoma and a synovial chondromatosis. The patient with chondromatosis also carried this same mutation in the germline. However, this mutation was also identified in leukocyte DNA from three of 127 (2.4%) control subjects without cartilage tumors, suggesting it may represent a rare SMO variant. Constitutive activation of the hedgehog signaling pathway in chondrosarcoma is rarely caused by PTCH-1 or SMO mutations. [corrected]
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