Red Cell Distribution Width: an Unacknowledged Predictor of Mortality and Length of Stay following Revision Arthroplasty

Introduction Red blood cell distribution width (RDW), a measure of variability in size of circulating erythrocytes, is routinely reported in complete blood cell analysis, and together with mean cell volume (MCV) has conventionally been used to distinguish the cause of anemia. It is calculated by (Standard deviation of MCV÷ mean MCV) x 100, with normal range being 11.5%-14.5%. Several recent publications have described RDW as an independent predictor of adverse outcome and mortality in patients with different underlying medical conditions such as acute and chronic heart failure, peripheral artery disease, chronic pulmonary disease and acute kidney injury1. The purposes of this study were 1) to investigate possible relationship between RDW levels and length of stay (LOS) and mortality following revision total joint arthroplasty (TJA), and if that correlation existed, 2) to develop predictive models for LOS and mortality based on preoperative patient-related factors including RDW values

Operative Environment

Postoperative SSIs are believed to occur via bacterial inoculation at the time of surgery or as a result of bacterial contamination of the wound via open pathways to the deep tissue layers.1–3 The probability of SSI is reflected by interaction of parameters that can be categorized into three major groups.2 The first group consists of factors related to the ability of bacteria to cause infection and include initial inoculation load and genetically determined virulence factors that are required for adherence, reproduction, toxin production, and bypassing host defense mechanisms. The second group involves those factors related to the defense capacity of the host including local and systemic defense mechanisms. The last group contains environmental determinants of exposure such as size, time, and location of the surgical wound that can provide an opportunity for the bacteria to enter the surgical wound, overcome the local defense system, sustain their presence, and replicate and initiate local as well as systemic inflammatory reactions of the host. The use of iodine impregnated skin incise drapes shows decreased skin bacterial counts but no correlation has been established with SSI. However, no recommendations regarding the use of skin barriers can be made (see this Workgroup, Question 27)

Isolated multiple lumbar transverse process fractures with spinal instability: an uncommon yet serious association

Isolated vertebral transverse process fractures of thoracolumbar spine without other vertebral injuries and neurological deficit are generally considered as minor injuries with no concern for associated spinal instability. This report describes a case of multiple lumbar transverse fractures associated with an unexpected yet clinically significant spinal instability. A young male presented with right flank pain following being pushed and trapped against the ground by a reversing truck. The neurological examination was normal, and computed tomography (CT) imaging revealed multiple fractures at right transverse processes from L1 to L5, a single left-sided transverse process fracture at L2 and subtle facet joint distraction without other spinal lesions or visceral injuries. The injury was initially deemed as stable requiring symptomatic treatment and in-patient observation. However, discharge upright X-rays taken in a brace showed marked subluxation of L2/L3 and L3/L4 levels. Magnetic resonance imaging revealed significant discoligamentous injuries involving anterior and posterior longitudinal ligaments, annulus fibrosus as well as posterior ligamentous complex. The patient underwent posterior spinal instrumentation and fusion of L1 to L5. This is the first case description of association of multisegmental lumbar transverse process fractures with notoriously unstable injuries of the major soft-tissue stabilizers of the spine presenting subtle changes on CT images. When a seemingly benign spinal injury is caused by high-energy trauma, careful scrutiny for associated instability is needed. In this case, the standing in-brace X-ray was able to avoid a misdiagnosis and potentially unfavourable outcome