Chronic Wear-Induced Bearing Dislocation in a Fixed-Bearing Unicompartmental Knee Arthroplasty: A Case Report.

Case: We present a case of late onset, bearing wear-induced failure of locking mechanism, resulting in bearing dislocation and rapidly progressive severe metallosis in a medial fixed-bearing (FB) unicompartmental knee arthroplasty (UKA). Conclusion: Bearing dislocation is a rare complication of chronic wear in FB UKA, and early recognition is essential to prevent metallic component articulation-induced metallosis and catastrophic failure.

Impaired Transmigration of Myeloid-Derived Suppressor Cells across Human Sinusoidal Endothelium Is Associated with Decreased Expression of CD13.

Human monocytic myeloid-derived suppressor cells (MO-MDSCs) within the hepatic compartment suppress inflammation and impair immune surveillance in liver cancer. It is currently not known whether recruitment of MO-MDSCs from blood via hepatic sinusoidal endothelium (HSEC) contributes to their enrichment within the hepatic compartment. We compared the transmigratory potential of MO-MDSCs and monocytes after adhesion to hepatic endothelial monolayers in flow-based assays that mimic in vivo shear stress in the sinusoids. Despite comparable binding to HSEC monolayers, proportionally fewer MO-MDSCs underwent transendothelial migration, indicating that the final steps of extravasation, where actin polymerization plays an important role, are impaired in MO-MDSCs. In this article, we found reduced levels of CD13 on MO-MDSCs, which has recently been reported to control cell motility in monocytes, alongside reduced VLA-4 expression, an integrin predominantly involved in adherence to the apical side of the endothelium. CD13 and VLA-4 blocking and activating Abs were used in flow-based adhesion assays, live-cell imaging of motility, and actin polymerization studies to confirm a role for CD13 in impaired MO-MDSC transmigration. These findings indicate that CD13 significantly contributes to tissue infiltration by MO-MDSCs and monocytes, thereby contributing to the pathogenesis of hepatic inflammation.

Introduction to Lymphocyte Trafficking in Disease.

Lymphocytes are the key effector cells of the adaptive immune response but are also implicated in the development of chronic inflammatory diseases such as type 2 diabetes, cardiovascular disease, inflammatory bowel disease, and allergy. In order to understand the mechanisms responsible for the global increase in such debilitating conditions it is vital to appreciate the complexity of immune cell trafficking into tissue under normal and inflamed conditions. In this chapter we introduce the mechanisms of immune cell recruitment into tissue and highlight how these processes have been targeted by new therapeutic entities based on blocking integrin or chemokine function.

The impact of timing of cholecystectomy following gallstone pancreatitis.

INTRODUCTION: Current guidelines for the management of acute gallstone pancreatitis recommend cholecystectomy as definitive treatment during primary admission or within 2 weeks of discharge, with the aim of preventing recurrent pancreatitis. However, cholecystectomy during the inflammatory phase may increase surgical complication rates. This study aimed to determine whether adherence to the guidelines prevents recurrent pancreatitis while minimising surgical complications. METHODS: Multi-centre review of seven UK hospitals, indentifying patients presenting with their first episode of gallstone pancreatitis between 2006 and 2008. RESULTS: A total of 523 patients with gallstone pancreatitis were identified, of which 363 (69%) underwent cholecystectomy (72 during the primary admission or within 2 weeks of discharge; 291 following this). Overall, 7% of patients had a complication related to cholecystectomy of which a greater proportion occurred when cholecystectomy was performed within guideline parameters (13% vs 6%; p = 0.07). 11% of patients were readmitted with recurrent pancreatitis prior to surgery, with those undergoing cholecystectomy outside guideline parameters being most at risk (p = 0.006). CONCLUSION: This study suggests cholecystectomy within guideline parameters significantly reduces recurrence of pancreatitis but may increase the risk of surgical complications. A prospective randomised study to assess the associated morbidity is required to inform future guidelines.

Dexamethasone reduces emesis after major gastrointestinal surgery (DREAMS).

BACKGROUND: Postoperative nausea and vomiting is one of the most common complications affecting patients after surgery and causes significant morbidity and increased length of hospital stay. It is accepted that patients undergoing surgery on the bowel are at a higher risk. In the current era of minimally invasive colorectal surgery combined with enhanced recovery, reducing the incidence and severity of postoperative nausea and vomiting is particularly important. Dexamethasone is widely, but not universally used. It is known to improve appetite and gastric emptying, thus reduce vomiting. However, this benefit is not established in patients undergoing bowel surgery, and dexamethasone has possible side effects such as increased risk of wound infection and anastomotic leak that could adversely affect recovery. DESIGN: DREAMS is a phase III, double-blind, multicenter, randomized controlled trial with the primary objective of determining if preoperative dexamethasone reduces postoperative nausea and vomiting in patients undergoing elective gastrointestinal resections. DREAMS aims to randomize 1,350 patients over 2.5 years.Patients undergoing laparoscopic or open colorectal resections for malignant or benign pathology are randomized between 8 mg intravenous dexamethasone and control (no dexamethasone). All patients are given one additional antiemetic at the time of induction, prior to randomization. Both the patient and their surgeon are blinded as to the treatment arm.Secondary objectives of the DREAMS trial are to determine whether there are other measurable benefits during recovery from surgery with the use of dexamethasone, including quicker return to oral diet and reduced length of stay. Health-related quality of life, fatigue and risks of infections will be investigated. TRIAL REGISTRATION: ISRCTN21973627.