MoM Hip Resurfacing: A Reprieve in Mortality Advantage?

Last week's articles on rheumatology topics in the major non-rheumatology journals.Mortality rates at 10 years after metal-on-metal hip resurfacing compared with total hip replacement in England: retrospective cohort analysis of hospital episode statistics
BMJ, 27 November 2013

Patients with hip osteoarthritis (OA) undergoing metal-on-metal (MoM) hip resurfacing had half the 10-year all-cause mortality of those undergoing cemented or uncemented total hip replacement, in a retrospective cohort study using propensity score matching.

Ten-year cumulative mortality was 3.6% for MoM vs 6.1% for cemented joints and 3% for MoM in a different cohort vs 4.1% for uncemented. The study drew on all adults undergoing primary elective hip repair for OA in the English hospital episode database and on national mortality records. Each patient undergoing MoM hip resurfacing was matched to three comparable controls, assessing Mom separately against cemented and uncemented joints in cohorts that totaled separately more than 15,500 for the MoM group and over 46,000 hip replacement recipients.

About 60% of all deaths in this cohort were due to either malignant cancer or ischemic heart disease. The authors offered numerous possible contributing factors to the observed survival advantage, adding that there may also be residual unmeasured confounding effects and a need to balance the survival statistics against the known adverse effects associated with MoM resurfacing, including local soft-tissue reactions, femoral neck fractures, elevated systemic ion levels, and early failure among female patients.


Seminar: Adult haemophagocytic syndromeLancet, November 27, 2013

Autoimmune diseases, particularly systemic lupus erythematosus, and adult-onset Still’s disease, and sometimes rheumatoid arthritis and vasculitis, are major causes of adult hemophagoctic syndrome, which is described at length in this overview. Other causes are infection and neoplasm, and these concomitant illnesses must always be differentiated from the syndrome. 

The cardinal features of adult hemophagocytic syndrome are high fever, adenopathies and hepatosplenomegaly, and often progressive multiple organ failure, with mortality of 41% in one large study. Rare in adults and more common in the pediatric population, the syndrome involves activation of antigen-presenting cells without their normal controls, releasing a cytokine storm.

Treatment is based on the pediatric syndrome, with guidelines based on case series, uncontrolled studies, and expert opinion.


Case Report: Rash and arthralgia caused by hepatitis ELancet, November 30, 2013

A case of rash and arthralgia was linked to the hepatitis E virus (HEV), indicating that HEV can be found in developed countries. In this report, a woman with no travel history produced HEV antibodies and RNA. The report notes that other cases have been found in Scotland and HEV has been isolated from mussels harvested along that coastline.

The 52-year-old woman  presented with polyarthritis, pain and discharge from the eyes, as well as headache, loss of appetite, and a maculopapular, non-itchy rash all over her body. The authors observed that HEV has a variable presentation.