Dissociation of the S-ROM metal-backed polyethylene acetabular liner--a case report and literature review.

The authors report a case of early failure of a total hip arthroplasty with dissociation of the polyethylene liner of an S-ROM Oblong Cup*, which presented as a dislocation. Initial closed reduction of the dislocation was not possible. Open exploration of the hip revealed that the modular Poly Dial* polyethylene acetabular liner had become dislodged from the acetabular cup. The liner was revised and a stable reduction of the hip was achieved. To our knowledge, no previous case of dissociation of the polyethylene liner from the S-ROM Oblong acetabular component has been reported. A review of the literature with other relevant cases is presented.

Visceral receptors and their afferents in the caudal mesenteric nerve of the duck.

1. The behaviour and reactivities of visceral receptors to different mechanical and chemical stimuli in simple unit preparations from the caudal mesenteric nerve of adult ducks were studied to examine the physiological roles of such receptors. 2. In total, 83 single unit activities were recorded from the caudal mesenteric nerve. 3. Receptors were grouped according to their locations in different layers of the rectum as (i) over the branching points of the blood vessel or in the serosal layer, (ii) in the muscle layer or (iii) in the mucous membrane of the rectum. 4. All the receptors, both spontaneous and non-spontaneous, responded to mechanical probing. Receptors of the muscle layer responded to distension also and showed a slowly-adapting nature. Most of the receptors of the other two groups were of the rapidly-adapting type. 5. Conduction velocity ranged from 0.76 to 34.6 m/s. 6. Sympathetic afferent fibres from the hind gut ascend along the intestinal nerve and join the caudal mesenteric nerve via the colonic ganglion.