Femoral neuropathy following total hip arthroplasty: review and management guidelines.

Femoral neuropathy following primary or revision total hip arthroplasty (THA) is a rare but acknowledged complication. Treatment of femoral neuropathy has long been debated and there is a paucity of accepted principles on which to base management. Currently, no definitive management protocol exists in the literature. A literature search was performed by a review of PubMed, Google Scholar and OVID articles published from 1972-2011. The literature reports an incidence rate of femoral neuropathy following THA ranging from 0.1 to 2.4 percent. Determining the precise aetiology, establishing a diagnosis and subsequent treatment of femoral nerve injury remains a difficult task, with conservative management remaining the treatment benchmark. In this review, we aim to summarise the aetiologies and risk factors associated with femoral neuropathy following THA and provide management guidelines.

Clopidogrel dilemma for orthopaedic surgeons.

BACKGROUND: Patients medicated with clopidogrel who require orthopaedic surgery present a particular challenge. Whether in an emergency or elective situation the orthopaedic surgeon must balance the risks of ceasing clopidogrel versus the risk of increased bleeding that dual antiplatelet therapy generates. METHOD: This paper reviews the current published evidence regarding the risks of continuing clopidogrel, the risks of discontinuing clopidogrel and associated considerations such as venous thromboprophylaxis. RESULTS: Little good quality evidence exists in regard to perioperative clopidogrel for orthopaedic surgery. Available evidence across non-cardiac and cardiac surgery were assessed and presented in regards to current practices, blood loss for orthopaedic operations, risks when continuing clopidogrel, risks of stopping clopidogrel and also the consideration of venous thromboembolism. CONCLUSIONS: The patients at greatest risk, when discontinuing clopidogrel therapy, are those with drug eluting stents who may be at risk of stent thrombosis. Where possible, efforts should be made to continue clopidogrel therapy through the perioperative period, taking precautions to minimize bleeding. If the risk of bleeding is too high, antiplatelet therapy must be reinstated as soon as considered reasonable after surgery. In addition, patients on clopidogrel who sustain a fall or other general trauma need to be carefully assessed because of the possibility of occult bleeding, such as into the retroperitoneal space. Until more definitive evidence becomes available, this review aims to provide a guide for the orthopaedic surgeon in dealing with the difficult dilemma of the patient on clopidogrel therapy, recommending that orthopaedic surgeons take a team approach to assess the individual risks for all patients and consider continuation of clopidogrel therapy perioperatively where possible.

Oral delivery of macromolecules: rationale underpinning Gastrointestinal Permeation Enhancement Technology (GIPET).

Oral delivery of macromolecular drugs, particularly peptides and proteins, is the focus of many academic and industrial laboratories. Armed with an increased understanding of the structure and regulation of intestinal epithelial junctional complexes of the paracellular barrier, the development of permeation enhancement technology initially focused on the specific and reversible opening of tight junctions in order to enable oral delivery. Despite intense research, none of these specific tight junction-opening technologies has yet been approved in an oral drug product, likely because of poor efficacy. Less specific enhancer technologies with a long history of safe use in man have additional surfactant-like effects on the transcellular pathway that lead to improved efficacy. These are likely to be the first to market for selected poorly permeable peptides. This review presents a summary of some approaches taken to intestinal permeation enhancement and explores in detail the oral delivery system developed by Merrion Pharmaceuticals, Gastrointestinal Permeation Enhancement Technology (GIPET).