Squeaking Hip Arthroplasties : A Tribological Phenomenon

The clinical incidence of squeaking has been reported with increasing frequency, with ceramic-on-ceramic bearings seemingly most affected. This study investigated potential causes of squeaking in hard-on-hard hip bearings through 2 sets of experimental conditions. Bearing clearance appeared to affect the incidence of squeaking in metal-on-metal surface arthroplasties. The addition of third-body particles to the interface for total hip arthroplasties also affected the incidence of squeaking. In both studies, the incidence of squeaking correlated well with elevated friction. The findings of this study suggest that a likely cause of squeaking in the hip arthroplasty is adverse tribological conditions caused by suboptimal lubrication. There are numerous factors that may cause the suboptimal lubrication, and therefore, it is unlikely that an individual cause for squeaking will be identified.     

Cost of care according to disease-modifying therapy in Mexicans with relapsing-remitting multiple sclerosis

Limited data exist on the costs of care of patients with multiple sclerosis (MS) in low- to middle-income nations. The purpose of this study was to describe the economic burden associated with care of Mexican patients with relapsing-remitting MS in a representative sample of the largest institution of the Mexican public healthcare system. We analysed individual data of 492 patients (67 % women) with relapsing-remitting MS registered from January 2009 to February 2011 at the Mexican Social Security Institute. Direct costs were measured about the use of diagnostic tests, disease-modifying therapies (DMTs), symptoms control, medical consultations, relapses, intensive care and rehabilitation. Four groups were defined according to DMT alternatives: (1) interferon beta (IFNβ)-1a, 6 million units (MU); (2) IFNβ-1a, 12MU; (3) IFNβ-1b, 8MU; and (4) glatiramer acetate. All patients received DMTs for at least 1 year. The most frequently used DMT was glatiramer acetate (45.5 %), followed by IFNβ-1a 12MU (22.6 %), IFNβ-1b 8MU (20.7 %), and IFNβ-1a 6MU (11.2 %). The mean cost of a specialised medical consultation was €74.90 (US $107.00). A single relapse had a mean total cost of €2,505.97 (US $3,579.96). No differences were found in annualised relapse rates and costs of relapses according to DMT. However, a significant difference was observed in total annual costs according to treatment groups (glatiramer acetate being the most expensive), mainly due to differences in unitary costs of alternatives. From the public institutional perspective, when equipotent DMTs are used in patients with comparable characteristics, the costs of DMTs largely determine the total expenses associated with care of patients with relapsing-remitting MS in a middle-income country.     

Clinical characteristics and treatment of malignant brainstem gliomas in elderly patients

Adult brainstem gliomas (BSG) are uncommon tumors that constitute only 2% of all brain tumors. Due to its rare occurrence in the elderly (60 years and older), there is no literature discussing the natural history, prognosis, and best treatment strategy for malignant BSG in this population to our knowledge. We report seven elderly patients with malignant BSG and propose treatment strategies to manage these aggressive tumors. The median age at onset in this cohort was 65 years, with the majority of patients being male (71.4%) and Caucasian (85.7%). The median duration of symptoms prior to presentation was 0.5 months, with the most common symptoms being facial weakness, blurry vision, headache, and extremity weakness. Tumors were most commonly located in the pons (85.7%), with one tumor being located in the tectal plate. Five of seven (71.4%) patients underwent biopsies, with two patients undergoing partial resections. Following tissue diagnosis, patients received radiation therapy and concurrent temozolomide, followed by additional chemotherapeutics upon progression. Side effects as a result of treatment were seen in three patients and all involved reversible hematological complications such as neutropenia and thrombopenia. The median time to progression was 6.7 months and the median overall survival was 13.5 months. While malignant BSG in elderly patients are aggressive gliomas with an overall poor prognosis, these patients are able to safely undergo aggressive chemoradiotherapy, resulting in improved survival. Resection may be considered for select patients in which the tumor is mostly exophytic, near the brainstem surface, and easily accessible.     

Cervicofacial necrotizing fasciitis following periodontal abscess

Soft tissue infections are characterized by acute inflammation, diffuse edema, and suppuration, and are often associated with symptoms such as malaise, fever, tachycardia, and chills. Necrotizing fasciitis is a destructive bacterial infection affecting subcutaneous tissue and superficial fascia and is associated with high rates of mortality. It usually involves the abdomen and extremities, but it also can occur in the head and neck. Early diagnosis is critical and the most commonly accepted treatment includes radical surgical intervention and administration of broad-spectrum antibiotics. This article reports and discusses the case of a patient with odontogenic cervicofacial necrotizing fasciitis, and emphasizes the importance of early and effective treatment.     

Analysis of Risk Factors for Gunshot Wound Infection in a Nigerian Civilian Trauma Setting

Background

Survivors of firearm injury are at risk of wound infection. On average, civilian gunshot wound infection rates in developing countries are relatively high and almost on a par with infection rates in war trauma settings. Overall, there are limited data on civilian gunshot wound infection and its predisposing factors. The aim of this study was to determine the risk factors for gunshot wound infection in a civilian trauma setting of a developing nation.

Materials and method

This was a retrospective analysis of data on the entire patients who presented in Federal Teaching Hospital Abakaliki with firearm injury from January 2005 to December 2014.

Results

There were 196 patients, and wound infection was a complication in 58 (29.6 %) of them. The significant factors for high wound infection rate in univariate analysis were perforating wound (p < 0.001), high velocity injury (p < 0.001), haematocrit <30 % (p < 0.001), presence of fracture (p < 0.001), hollow viscus injury (p < 0.001) and injury to hospital arrival interval later than 6 h (p < 0.014). Anatomical site of injury correlated with infection rate (p < 0.001), highest rate (40.6 %) in lower extremity and least (9.1 %) in head and neck wounds. Multivariate logistic regression analysis identified haematocrit (p < 0.001), perforating wound (p < 0.021), presence of fracture (p < 0.043) and hollow viscus injury (p < 0.039) as independent predictors of gunshot wound infection.

Conclusion

The independent predictors of infection identified in this study call for judicious replacement of blood loss and high priority accorded to perforating wound, fractures and hollow viscus injury in interventions aimed at reducing gunshot wound infection rate.