Incomplete seating of the liner with the Trident acetabular system: a cause for concern?

We reviewed the initial post-operative radiographs of the Trident acetabulum and identified a problem with seating of the metal-backed ceramic liner. We identified 117 hips in 113 patients who had undergone primary total hip replacement using the Trident shell with a metal-backed alumina liner. Of these, 19 (16.4%) were noted to have incomplete seating of the liner, as judged by plain anteroposterior and lateral radiographs. One case of complete liner dissociation necessitating early revision was not included in the prevalence figures. One mis-seated liner was revised in the early post-operative period and two that were initially incompletely seated were found on follow-up radiographs to have become correctly seated. There may be technical issues with regard to the implanting of this prosthesis of which surgeons should be aware. However, there is the distinct possibility that the Trident shell deforms upon implantation, thereby preventing complete seating of the liner.

Driving whilst plastered: is it safe, is it legal? A survey of advice to patients given by orthopaedic surgeons, insurance companies and the police.

Many patients, immobilised in a plaster cast after a fracture of the upper or lower limb, wish to drive. They frequently ask permission to do so from the treating surgeon. Insurance companies are apparently willing to insure these patients to drive if they obtain their doctors permission. The DVLA guidelines are unhelpful in these circumstances. We therefore established current practice within the south west region by canvassing 126 consultant orthopaedic surgeons, 27 insurance companies and the 6 regional police constabularies, sending them specific clinical scenarios and asking how they would advise these patients regarding safety to drive. The results were as follows: sixty-seven (53%) of surgeons responded of which 97% gave specific advice regarding safety to drive. The insurance companies were generally unwilling to respond and a national response was received from the Association of Chief Constables, which specifically stated that safety to drive was for the individual patient to decide and the doctor should not give advice. We consider this to be unsatisfactory for all parties and suggest how this situation could be improved for both the patient and other road users welfare.

Aprotinin (Trasylol) does not reduce bleeding in primary total hip arthroplasty.

This is a randomized, double-blind, controlled study of the effects of aprotinin (Trasylol) during primary total hip arthroplasty. Sixty patients were randomized to receive either 1.5 x 10(6) KIU of aprotinin or a similar volume of normal saline as a bolus preoperatively. Blood loss was measured from the femoral canal at the time of surgery. An estimate of the total blood loss during the operation was made, and the transfusion requirement was recorded. There was no significant difference between the groups in terms of total blood loss, postoperative hemoglobin, or transfusion requirement. In the group that received aprotinin, there was a trend toward reduced blood loss from the femoral canal, but this was not statistically significant. The results of this study do not support the routine use of aprotinin in primary total hip arthroplasty.

Analysis of responses observed in mesenteric microcirculation of the rat during systemic hypoxia.

1. Direct observations were made of responses to systemic hypoxia (breathing 12 or 6% O2 for 3 min) evoked in terminal arterioles (TA, 14-30 microns internal diameter), precapillary arterioles (PCA, 8-18 microns), collecting venules (CV, 12-30 microns) and small veins (SV, 20-50 microns) of the mesenteric circulation of the anaesthetized rat. Changes in vessel diameter were recorded before and after local blockade of alpha-adrenoreceptors with phentolamine when the mesentery was covered with Saran Wrap, which is impermeable to O2, and then after removal of the Saran Wrap, which would have kept local PO2 relatively high even during systemic hypoxia. 2. The majority of TA showed an initial decrease in diameter of 14 +/- 1% (mean +/- S.E.M.). These responses were reversed to increases in diameter (12 +/- 2%) after phentolamine, but virtually abolished after removal of the Saran Wrap (0.3 +/- 2%). 3. Some PCA showed similar behaviour to the TA; others showed an increase in diameter (11 +/- 1%). The increases in diameter were accentuated after phentolamine (16 +/- 1%), but were reduced after removal of the Saran Wrap (6 +/- 2%). 4. CV and SV showed either a decrease in diameter followed by relaxation towards control levels, or an increase in diameter that waned before hypoxia ceased (6 +/- 1% and 1 +/- 1%, respectively). The responses of CV were not altered by phentolamine (8 +/- 1%), but SV showed larger increases in diameter (5 +/- 1%).(ABSTRACT TRUNCATED AT 250 WORDS)