Posterior wall acetabular fracture fixation: A mechanical analysis of fixation methods.

Stable, anatomical fixation of acetabular fractures gives the best chance of successful outcome, while penetration of the acetabular articular surface with screws is associated with poor outcomes. Spring plates are an alternative to interfragmentary lag screws when penetration is a concern. A mechanical study comparing fracture stability and construct stiffness of three fixation methods for posterior wall acetabular fractures with transverse comminutions was performed. The three fixation methods tested were a posterior wall rim plate, a posterior wall buttress plate with separate lag screws and a posterior wall plate with two spring plates. Nine samples were tested, three for each fixation method. Two-dimensional motion analysis was used to measure fracture fragment displacement and construct stiffness. After two 6000 cycle-loading protocols, to a maximum 1.5 kN, the mean fracture displacement was 0.154 mm for the rim plate model, 0.326 mm for the buttress plate and 0.254 mm for the spring plate model. Mean maximum displacement was significantly less for the rim plate fixation than the buttress plate (p = 0.015) and spring plate fixation (p = 0.02). The rim plate was the stiffest construct 10,962 N/mm, followed by the spring plate model 5637 N/mm and the buttress plate model 4882 N/mm. Based on data obtained in this study, where possible a rim plate with interfragmentary lag screws should be used for isolated posterior wall fractures as this is the stiffest and most stable construct. When this method is not possible, spring plate fixation is a safe and a superior alternative to a posterior buttress plate method.

The surgical management of patients who deliberately self-harm.

INTRODUCTION: Deliberate self-harm is a common problem that often requires orthopaedic treatment. Patients with injuries due to deliberate self-harm are often referred to our unit. This study assessed the type of treatment required and the cost of treatment. PATIENTS AND METHODS: We undertook a retrospective survey of deliberate self-harm patients with known ICD-10 psychiatric disorders admitted for orthopaedic care from a medium-secure, female-only, psychiatric unit. Data were collected on admission rate, duration of stay, surgical interventions and complications. RESULTS: Over a 36-month period there were 73 admissions for 15 patients (mean age, 25.1 years) requiring 65 operative interventions, a mean of 4.3 (range, 0-9) per patient. Over 50% of patients were admitted more than 3 times, totalling 416 hospital bed-days and 80% had methicillin-resistant Staphylococcus aureus (MRSA) isolated. The orthopaedic treatment costs for these patients was 453,000 pounds during the period studied. DISCUSSION: The significant resources required to manage this patient cohort demonstrates the need for a co-ordinated management policy. We recommend day-case surgery for infected wounds only. Postoperatively, wounds should be protected with plaster of Paris. All patients with deliberate self-harm should be regarded as being infected with MRSA.

Electrical Detection of Proteins and DNA using Bioactivated Microfluidic Channels: Theoretical and Experimental Considerations.

In order to detect diseases like cancer at an early stage while it still may be curable, it's necessary to develop a diagnostic technique which can rapidly and inexpensively detect protein and nucleic acid biomarkers, without making any sacrifice in the sensitivity. We have developed a technique, based on the use of bioactivated microfluidic channels integrated with electrodes for electrical sensing, which can be used to detect protein biomarkers, target cells, and DNA hybridization. In this paper, we discuss the theoretical detection limits of this kind of sensor, and also discuss various experimental considerations in the electrical characterization of our device. In particular, we discuss the temperature dependence, the impedance drift, the noise sources, and various methods for optimizing the signal to noise ratio.

Changes in the four-strand hamstring graft in anterior cruciate ligament reconstruction in the skeletally-immature knee.

The potential harm to the growth plate following reconstruction of the anterior cruciate ligament in skeletally-immature patients is well documented, but we are not aware of literature on the subject of the fate of the graft itself. We have reviewed five adolescent males who underwent reconstruction of the ligament with four-strand hamstring grafts using MR images taken at a mean of 34.6 months (18 to 58) from the time of operation. The changes in dimension of the graft were measured and compared with those taken at the original operation. No growth arrest was seen on radiological or clinical measurement of leg-length discrepancy, nor was there any soft-tissue contracture. All the patients regained their pre-injury level of activity, including elite-level sport in three. The patients grew by a mean of 17.3 cm (14 to 24). The diameter of the grafts did not change despite large increases in length (mean 42%; 33% to 57%). Most of the gain in length was on the femoral side. Large changes in the length of the grafts were seen. There is a considerable increase in the size of the graft, so some neogenesis must occur; the graft must grow.

Bacteriology of the stomach immediately following vagotomy: the growth of Candida albicans.

With the rise in pH of gastric juice that results from vagotomy, there is a high incidence of intraluminal gastric Candida albicans overgrowth in the immediate postoperative period. There appears to be no clear cut correlation between gastric Candida overgrowth and the post-vagotomy diarrhea syndrome. Mycostatin has not had a significant affect upon this diarrhea.