Biomechanical analysis of impending femoral neck fractures: the role of percutaneous cement augmentation for osteolytic lesions.

BACKGROUND: Management of impending pathologic femoral neck fractures includes internal fixation, arthroplasty and megaprostheses. The study aim was to determine the augmentative effect of cement injection for minimally invasive treatment of femoral neck lesions. METHODS: Twenty-seven cadaveric femora received a simulated osteolytic lesion previously shown to decrease the femur's failure load by 50%. Specimens were allocated to three groups of nine and loaded to failure in simulated single-leg stance: (1) percutaneous cementation + internal fixation (PCIF); (2) percutaneous cementation (PC); and (3) internal fixation (IF). Lesion-only and augmented finite element models were virtually loaded and stresses were queried adjacent to the lesion. FINDINGS: PCIF resulted in the largest failure load though the increase was not significantly greater than the PC or IF groups. Inspection of the PC and PCIF specimens indicated that the generation of a cement column that spanned the superior and inferior cortices of the femoral neck increased failure loads significantly. Finite element analysis indicated that IF and PCIF constructs decreased the stress adjacent to the lesion to intact femur levels. Cementation without superior-to-inferior femoral neck cortical contact did not restore proximal femoral stress toward the intact condition. INTERPRETATION: Internal fixation alone and internal fixation with or without cementation produce similar levels of mechanical augmentation in femora containing a high-risk lesion of impending fracture. A cement injection technique that produces a cement column contacting the superior and inferior femoral neck cortices confers the highest degree of biomechanical stability, should percutaneous cementation alone be performed.

Treatment and complications in orthopaedic trauma patients with symptomatic pulmonary embolism.

OBJECTIVES: The purpose of this study is to characterize the presentation, size, treatment, and complications of pulmonary embolism (PE) in a large series of orthopaedic trauma patients who developed PE after injury. METHODS: We reviewed the records of orthopaedic trauma patients who developed a PE within 6 months of injury at 9 trauma centers and 2 tertiary care facilities. RESULTS: There were 312 patients, 186 men and 126 women, average age 58 years. Average body mass index was 29.6, and average Injury Severity Score was 18. Seventeen percent received anticoagulation before injury, and 5% had a history of PE. After injury, 87% were placed on prophylactic anticoagulation and 68% with low-molecular weight heparin. Fifty-three percent of patients exhibited shortness of breath or chest pain. Average heart rate and O2 saturation before PE diagnosis were 110 and 94%, respectively. Thirty-nine percent had abnormal arterial blood gas, and 30% had abnormal electrocardiogram findings. Eighty-nine percent had computed tomography pulmonary angiography for diagnosis. Most clots were segmental (63%), followed by subsegmental (21%), lobar (9%), and central (7%). The most common treatment was unfractionated heparin and Coumadin (25%). Complications of anticoagulation were common: 10% had bleeding at the surgical site. Other complications of anticoagulation included gastrointestinal bleed, anemia, wound complications, death, and compartment syndrome. PE recurred in 1% of patients. Four percent died of PE within 6 months. CONCLUSIONS: This is the first large data set to evaluate the course of PE in an orthopaedic trauma population. The complications of anticoagulation are significant and were as common in patients with lower risk clots as those with higher risk clots.

Regeneration of a discoid meniscus after arthroscopic saucerization.

We report the case of a 5-year-old girl who presented to the clinic with recurrent knee pain after meniscal repair and saucerization at age 3. The finding of a regenerated discoid meniscus was confirmed arthroscopically and radiographically. To our knowledge, this is the first report in the literature to confirm regeneration of a discoid meniscus after saucerization. The case has significant implications for management of pediatric discoid meniscus tears and patient counseling, and is encouraging in terms of the potential for repair and regeneration of meniscal tissue, particularly in the very young pediatric population.

Intraoperative radiation exposure with the use of (18)F-FDG-guided thyroid cancer surgery.

Radio-guided surgery is an established means for surgeons to identify a target of interest for biopsy or excision. This technique is used for a variety of malignancies as well as minimally invasive parathyroid surgery. The primary radionuclide used for these procedures is technetium-99m (Tc-99m), but others have been used. Use of (18)fluorine-fluorodeoxyglucose ((18)F-FDG) in oncology has proliferated. This has created the opportunity to use (18)F-FDG as a potential radio tracer in the operating room. A pilot study of three patients with non-iodine avid thyroid cancers undergoing (18)F-FDG-guided revision thyroid cancer surgery is reported. Radiation exposure to operating room personnel was measured. Radiation exposure to the surgeon and staff members of an operating room is well below the limits of the National Regulatory Commission. Therefore, utilization of this radiopharmaceutical intraoperatively should not be limited in the future because of concern regarding exposure of operating room personnel to radiation.