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Biomedical subjects

R G Narechania

Publications and source records attributed to R G Narechania.

8 recordsLinked to original sources

Anterior cruciate ligament reconstruction using one-third of the patellar ligament, augmented by extra-articular tendon transfers.

Eighty patients with persistent clinical and functional instability of the knee due to anterior cruciate ligament insufficiency underwent the operation reported, in which one-third of the patellar ligament substitutes for the cruciate ligament and extraarticular tendon transfers, medial and lateral, augment the substitution. The patients were followed for a minimum of two years, and fifty returned for personal evaluation. The average follow-up was thirty-three months, with a range of two to five years. There were thirty-five male and fifteen female patients. The average age was twenty-three years. The average interval from initial injury to the index operation was two years. Meniscal tears and articular changes were noted in most of the patients. Forty-three (86 per cent) of the fifty patients had at least one torn meniscus, twenty-seven patients (54 per cent) had significant degenerative articular changes, and fourteen (28 per cent) had patellar articular changes. In the procedure described, eccentric placement of the tibial and femoral tunnels for more accurate placement of the patellar ligament substitute is essential. The over-all results were graded as excellent in thirty knees, good in seventeen, fair in one, and a failure in two. One knee that was classified as a failure showed excellent stability, but the patient had significant pain from chondromalacia of the patella, while significant pain and hyperesthesia from a neuroma was the reason for failure in the second patient.

Adolescent↗

A study of pressure distributions measured during balanced and unbalanced sitting.

An instrument that measures pressures distribution during normal and unbalanced sitting was developed and tested. Analysis of the distribution of pressure during sitting in fifteen normal patients showed that approximately 18 per cent of the body weight is distributed over each ischial tuberosity; 21 per cent, over each thigh; and 5 per cent, over the sacrum. Three patients who had problems with sitting balance showed foci of unequal pressure which are at risk for decubitus ulceration.

Adolescent↗

Effects of 1,24 dihydroxyvitamin D3 and calcitonin on fracture healing in adult rats.

Calcitonin and 1.25(OH)2D3 have opposite effects on the serum concentrations of Ca and P, as well as on bone resorption, and can be observed in the process of healing of standardized fracture in adult rats. The rats given 1.25(OH)2D3 had a stronger fracture callus and slightly less pronounced postfracture osteopenia. Calcitonin did not significantly influence the fracture healing but had a pronounced effect in preventing the osteopenia. The effects of 1.25(OH)2D3 are believed to be indirect, i.e., through the changes in the serum Ca X P product, whereas the osteopenia preventing action of calcitonin may come from direct effect on bone.

Animals↗

Anterior and posterior cruciate ligament reconstruction in rhesus monkeys.

Although numerous procedures have been described for the reconstruction of the anterior and posterior cruciate ligaments, there has been little evaluation of the viability and strength of these substitutes. Using microangiographic, histological, and biomechanical techniques, we studied the vascularity and tensile strength of the medial one-third of the patellar tendon at intervals after it had been inserted as a substitute for either the anterior or the posterior cruciate ligament in twenty-nine young adult Rhesus monkeys. For the anterior cruciate reconstruction (nineteen knees), we used and medial one-third of the patellar tendon elongated by a portion of the patella. For the posterior cruciate reconstruction (ten knees), we used the medial one-third of the patellar tendon lengthened by attached portions of the patella and tibia as a free graft. Both the anterior and the posterior cruciate ligament substitutes were revascularized at eight weeks, and at one year they had approximately 80 per cent of the tensile strength that they had prior to transfer.

Animals↗

Tartan Turf on trial. A comparison of intercollegiate football injuries occurring on natural grass and Tartan Turf.

We retro- and prospectively compared collegiate football injuries that occurred on the grass and Tartan Turf (3M Company, St. Paul, Minnesota) fields at the University of Wisconsin. Retrospective injury data were obtained from questionnaires returned by 235 of 450 athletes that competed from 1960 to 1973. Prospective injury data were obtained by examination of athletes injured from 1975 through 1977. Although the number of injuries occurring on each playing surface were not significantly different, the type and severity of injuries were significantly different. We found that significantly more serious sprains and torn ligaments occurred on grass than occurred on Tartan Turf. There were significantly more scrapes (minor injuries) on the Tartan Turf than on the grass. We conclude that we may be prematurely returning to natural grass playing surfaces, and--to the detriment of the athlete--ending production of one synthetic turf that helped reduce major injuries.

Athletic Injuries↗

Surgical injury to the lateral aspect of the knee. A comparison of transverse and vertical knee incisions.

We retrospectively evaluated postoperative straight lateral and anterolateral rotatory knee stability in patients having a lateral meniscectomy through vertical and horizontal capsular incisions. The knees of 20 patients with transverse (Bruser) and 20 patients with vertical (parapatellar) incisions were clinically and mechanically evaluated. Varus-vagus and anterior drawer measurements were obtained from our knee stress machine and clinical examinations. We found that (1) horizontal and vertical lateral capsular incisions do not produce straight lateral or anterolateral rotatory instability in patients with intact anterior cruciate ligaments, (2) a transverse lateral capsular incision may contribute to anterolateral rotatory instability, and (3) a vertical lateral capsular incision provides better visualization of the knee joint than a transverse incision.

Adult↗

Circumferential and axial strain in the proximal femur: effect of prosthesis type and position.

Because the Charnley-Müller prosthesis inserted in a varus position has been found subject to loosening, circumferential and longitudinal strain patterns were determined in proximal cadaver femora that had been instrumented with strain gauge rosettes and implanted with total hip replacement femoral prostheses. Both Charnley and Charnley-Müller prostheses were inserted in the varus, valgus, and neutral positions. An intact femur was similarly studied. Strain patterns in the test femora were altered by implant insertion, mainly by reducing longitudinal strain. Prosthesis type did not alter strain patterns but prosthesis position did. Valgus position produced compressive axial strain laterally and tensile strain medially at the tip of the prosthesis which was the reverse of that seen with varus position. Valgus position produced biaxial compressive strain at the medial calcar whereas varus position produced circumferential tension and axial compression at that location.

Biophysical Phenomena↗