Patellofemoral joint arthroplasty: patient selection,surgical technique and outcomes

Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome.     

Management of obsessive-compulsive disorder

Obsessive-compulsive disorder is an anxiety disorder characterized by compulsive rituals such as excessive washing and repeated checking and phobic avoidance. The treatment of choice is behavioural psychotherapy, namely exposure and response prevention.     

Prevention of arginine-vasopressin-induced motor disturbances by a potent vasopressor antagonist

The antivasopressor analog d(CH2)5Tyr(Me) arginine-vasopressin completely blocked the convulsive-like behavior and other severe motor disturbances which are normally observed following a second central arginine-vasopressin injection. This vasopressor antagonist appears to be selective for arginine-vasopressin-induced motor disturbances, in that the convulsive and motor effects of pentylenetetrazol and somatostatin were not altered significantly by pretreatment with the central antagonist. Results suggest that arginine-vasopressin-induced motor disturbances are mediated via central receptors. The classic antidiuretic (V2) type of arginine-vasopressin receptor does not appear to be involved, since the agonist 1-desamino-8-D-arginine-vasopressin did not elicit convulsive-like behavior or other severe motor disturbances 2 days following a first ('priming') injection of arginine-vasopressin.