Insufficient Stock Research Articles

Swanson silicone arthroplasty of the wrist in rheumatoid arthritis: A long-term follow-up

Twenty-three Swanson silicone rubber implants in patients with stage III or stage IV rheumatoid arthritis were reviewed at an average of 72 months after surgery. Minimum follow-up in patients with unrevised implants was 44 months. Results were rated good or excellent in 48%, fair in 4%, and poor in 48%. Pain was the primary indication for surgery. Patient satisfaction and pain relief were achieved in 63%. Implant fracture occurred in 52%. Revision rate was 30%, including one recommended revision. Radiographic changes consistent with particulate synovitis were seen in 30%. Prosthesis settling and bony resorption were seen in more than 75% of the patients. Survivorship analysis demonstrated 42% survival at 77 months. Progressive clinical and radiologic deterioration was seen. Swanson silicone rubber implant is recommended only in the very low demand patient with stage III or stage IV rheumatoid arthritis and in those with insufficient bone stock to allow total wrist arthroplasty with a metal-on-plastic design.

Mechanical failures in total hip replacement requiring reoperation.

During the years 1971 through mid-1977, approximately 3,000 total hip replacements were performed at The Hospital for Special Surgery using metal-to-plastic prostheses. During that period of time, thirty-five operations were done for mechanical failure in the absence of infection. The mechanical failures were distributed as follows: Fourteen patients had dislocations of the prostheses and seven patients had loosening of the femoral component, mostly with varus positioning of the femoral stem. Six patients, most of them heavy, active men, had fractures of the femoral stem. Three patients had loosening of the acetabular component. (In two of three there was insufficient bone stock over the acetabulum.) Four patients had proximal migration of the greater trochanter and one had a fracture-dislocation of the acetabulum. In all cases a technical or anatomical problem could be identified as the reason for mechanical failure necessitating reoperation. By careful preoperative planning, proper selection of procedures and positioning of prostheses, bone-grafting when necessary, and stricter attention to the technique of using cement, we could conceivably have avoided two-thirds of these failures.

The Needs of Selected Map Users: Mapping Expedients To Meet Military Requirements

Military requirements for map content are assessed to be similar to those of most other users; the major difference is in the degree of dependence on maps on the part of the soldier. In battle the commander must be provided with maps with the least possible delay. To compensate for the dearth of mapping at the soldiers' tactical scale, 1:50,000, the Canadian Forces' Mapping and Charting Establishment is developing a rapid mapping capability. Where maps do exist, improvised methods are often required to correct deficiencies in outdated maps or insufficient stocks. A few special-purpose products have been designed to provide specific information for military use. Les milieux militaires et civils ont des besoins analogues en ce qui a trait au contenu des cartes, la principale différence étant la plus grande dépendance des militaires vis-à-vis des cartes. En campagne, l'état-major doit pouvoir se procurer les cartes requises très rapidement. Pour rémédier au manque de cartes militaires à l'échelle tactique du 50,000e, le Service cartographique des Forces armées canadiennes a amorcé un programme de production rapide. Il lui faut parfois improviser des méthodes pour corriger les cartes périmées ou remédier a l'insuffisance des stocks. Certains produits spécialises ont été mis au point pour fournir des données particulières a des fins militaires.