Archives of orthopaedic and trauma surgery
-
Arch Orthop Trauma Surg · Jan 1990
Open fractures of the femur treated by the pin-in-plaster technique. Contribution to the art and practice of trauma surgery in the Third World.
In order to cope with the frequent lack of adequate and sufficient external fixator systems in Third World countries, the pin-in-plaster technique was adopted and used in the management of open fractures of the femur. It consists of the use of Steinmann and Schanz pins incorporated into a plaster of Paris cast. ⋯ The advantages and disadvantages of the method are discussed. The method is recommended as an effective improvisation of the Hoffman apparatus for use in exceptional circumstances, such as war and adverse socioeconomic conditions as are found in most Third World countries.
-
Animal studies can provide important information in the evaluation of new techniques and prosthetic designs in orthopedics. As a prerequisite they must parallel as closely as possible the human conditions they are modeling. An arthritic sheep model simulating the human clinical situation has previously been designed and reported by Phillips and Gurr. ⋯ Only one of the 12 cases showed postoperative avascularity of the femoral head. Radiologic follow-up and histologic examination showed features consistently and strikingly similar to those seen in human practice. The sheep hip with simulated arthritis provides a sensitive, clinically reproducible model for the future study of other arthroplasty types and problems.
-
Arch Orthop Trauma Surg · Jan 1990
Effect of direct-current stimulation on the growth plate. In vivo study with rabbits.
Electrical stimulation of 8 microA direct current was applied to the femoral distal growth plate of young rabbits for periods of 1, 2, and 3 weeks to examine the effect on bone growth. The results were analyzed using X-ray measurement, histological observation including tetracycline labeling, and glycosaminoglycans analysis. No obvious differences between the stimulated side and the control side were observed in the morphological and biochemical studies, but characteristic thickening of the growth plate caused by the accumulation of hypertrophic cells was found in the group stimulated for 2 weeks. Electricity affects the cell behavior of the growth plate, but it is necessary to find more appropriate conditions to stimulate obvious bone growth.
-
Arch Orthop Trauma Surg · Jan 1990
Pathology of the bone-cement interface in loosening of total hip replacement.
The histopathology of the bone-cement interface in nine retrieved hip prostheses is reported. Three cases presented features similar to those observed by Charnley in highly successful implants, and they were classified as stable prostheses, although signs of periprosthetic bone resorption were already present. ⋯ The polymorphous features of this connective membrane probably resulted from instability and movement at the bone-cement and stem-cement interfaces. On the basis of the pathological changes observed in the study, the process of loosening must be far advanced before it is detected on radiographs; it is suggested that scintigraphy is the best noninvasive technique to demonstrate macrophage activation and increased bone remodeling around the cement in the early phases of loosening.