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Background: First-generation highly cross-linked polyethylene liners have reduced the incidence of wear particle-induced osteolysis. However, failed acetabular liners have shown evidence of surface cracking, mechanical failure, and oxidative damage. This has led to the development of second-generation highly cross-linked polyethylene, which has improved wear and mechanical properties and resistance to oxidation in vitro. Owing to its recent introduction, there are no publications describing its clinical performance.Questions/purposes: We assessed early clinical wear of a second-generation highly cross-linked polyethylene liner and compared its clinical performance with the published results of hip simulator tests and with first-generation highly cross-linked polyethylene annealed liners.Patients and Methods: Twenty-one patients were enrolled in a prospective cohort study. Clinical outcome and femoral head penetration were measured for 19 patients at 6 months and 1 and 2 years postoperatively.Results: The median proximal head penetration was 0.009 mm and 0.024 mm at 1 and 2 years, respectively. The median two-dimensional (2-D) head penetration was 0.083 mm and 0.060 mm at 1 and 2 years, respectively. The median proximal wear rate between 1 and 2 years was 0.015 mm/year.Conclusions: The wear rate calculated was similar to the in vitro wear rate reported for this material; however, it was less than the detection threshold for this technique. Although longer followup is required for wear to reach a clinically quantifiable level, this low level of wear is encouraging for the future clinical performance of this material.Level Of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Objectives: To determine the effects of bone morphology on the interfacial mechanics of bone plate fixation., Design: A comparison of two bone plate designs using measures of contact area and force in three conditions of bone type., Intervention: The influence of bone plate design, bone type, and implant location on interfacial characteristics of contact area and average force were evaluated using pressure-sensitive film in cadaveric bone. Data were quantitated using computer-assisted image analysis., Main Outcome Measurements: Means of the two dependent variables in each of the three conditions were compared using analysis of variance., Results: In human femora and equine third metacarpi, there were no apparent differences in interface contact area attributed to bone plate design, although there were significant differences for interface contact force. In humeri, significant differences in both interface contact area and force were found between bone plate designs., Conclusions: Results show that bone surface topography and implant location are major determinants of the interfacial elements of contact area and average force between a plate and the bone to which it is applied.

Blunt carotid dissection (BCD) is a rare injury occurring in less than one in 1,000 victims of blunt injuries. Using a 4-year experience in a trauma system with 14 cases of BCD, we performed a matched blunt trauma patient case-control analysis to determine if there were patterns of injuries that were associated with increased risk of BCD. Patients with combinations of head, facial, and cervical spine injuries with or without extremity fractures proved to be at significantly increased risk for BCD. Duplex scanning appears to be a useful screening tool for these patients. Anticoagulation was the preferred treatment once neurologic deficits were present.

Studies have been conducted to characterize phenotypic and functional characteristics of murine and human cells after burn injury. The detailed analysis of T-cell distribution in the burned mouse, and the analysis of activation markers L3T4/Lyt-2 and Ia, reveals characteristic changes including the presence of "activated" suppressor cells during post-injury suppression. Studies of humoral markers suggest an increased production of IgG in burned animals upon sheep red blood cells (SRBC) challenge, accompanied by increased clearance or catabolism of serum antibody, which results in depressed serum levels. Finally, in vitro phagocytosis studies using fluorescein isothiocyanate (FITC)-labeled killed bacteria reveal that burn patient sera are clearly defective in their ability to promote opsonization of one or more specific organisms by neutrophils. The addition of exogenous IgG to the incubation medium improves this response, suggesting that postburn phagocytic depression is an opsonic defect, rather than an inhibitory effect of burn serum on neutrophils.

We present a case of extensive cutaneous chemical burns from sulfuric acid in a baby girl. The patient's age and the appearance of her wounds made it difficult to judge the depth of the wounds in the early stages of care. Because of the uniform appearance of the wounds and the large areas of injury, tangential excision was considered but delayed; the wounds were monitored with serial histologic biopsies for assessment of depth and progression of healing. The presence of viable dermal tissue and adnexal structures on histologic examination encouraged a program of observation and local wound care, which led to progressive healing of the wounds in 18 days. Histologic monitoring of the wounds proved to be a helpful adjunct in the clinical management of this difficult case.