Biomedical subjects

S W Siverhus

Publications and source records attributed to S W Siverhus.

4 recordsLinked to original sources

PubMed1990

Prosthesis-associated pseudomembrane-induced bone resorption.

A pseudomembranous structure invariably develops at the cement-bone interface of implanted prostheses in association with aseptic loosening. The tissue has histological characteristics of a foreign body reaction presumably initiated by repetitive microtrauma-associated release of methacrylate cement and polyethylene wear debris. Explant cultures of pseudomembrane and synovial tissue derived from osteoarthritic patients undergoing revision for cemented hip implant failure have been shown to produce interleukin-1, tumour necrosis factor and prostaglandin E2, recognized mediators of bone resorption. Further, the conditioned media obtained from pseudomembrane cultures could directly effect bone resorption by inducing 45Ca release from prelabelled limb bone rudiments. Results implicate the prosthesis-associated pseudomembrane in the pathogenesis of the bone resorptive process responsible for prosthesis failure.

Adult↗

PubMed1989

A cadaveric study of the anatomic variations of the recurrent motor branch of the median nerve.

Anatomic dissections were performed in 72 cadaveric upper extremities from 36 cadavers to determine the incidence of anomalous variations in the course of the median nerve and its branches. The classic recurrent motor branch anatomy was demonstrated in 86% of the dissections (62/72). Of the 10 variations noted (14% of all upper extremities), all were transretinacular branches that pierced the transverse carpal ligament 2 to 6 mm proximal to the distal edge. Of the six cadavers with anomalous branching, four (67%) had bilateral anomalies and two (33%) had unilateral branching.

Cadaver↗

PubMed1988

Ischemic necrosis of the femoral head. Treatment by core decompression.

Since 1977, we have performed twenty-one core decompressions in seventeen patients who had stage-I or II ischemic necrosis of the femoral head. The diagnosis was confirmed histologically in all but one patient. After a mean length of follow-up of thirty-nine months, healing was evident in eight hips (40 per cent) but not in the other twelve. All twelve hips required additional surgical treatment; the average length of time before the additional treatment was required was 9.2 months. The results of two intraoperative diagnostic tests (intramedullary pressure and saline stress tests) did not correlate with the results of biopsy. A perioperative fracture through the site of the decompression occurred in one of the twenty-one hips. Given the relatively poor long-term results and the considerable morbidity that was associated with core decompression, this treatment cannot be recommended.

Adult↗

PubMedDate not supplied

An anatomic basis for recurrence after Morton's neuroma excision.

Dissections of the common digital nerve and its branches were performed in the second and third web spaces in five fresh-frozen cadaveric feet. Plantarly directed nerve tetherings, which were histologically demonstrated to be nerve branches, were consistently present along the course of each common digital nerve. These plantarly directed nerve branches were found in highest concentration in the distal aspect of the common digital nerve proximal to the bifurcation into the proper digital branches. The presence of these nerve branches may contribute to the high incidence of Morton's neuroma recurrence either due to traumatic neuroma formation in the branches or to failure of proximal retraction of the more distally resected nerve stump.

Cadaver↗