Biomedical subjects

R Narechania

Publications and source records attributed to R Narechania.

3 recordsLinked to original sources

PubMed1986

Hex-nut loosening following compression instrumentation of the spine.

Two cases of failure of compression instrumentation using the slotted hook and bushing (SHB) system due to back-off of the hex nut and loosening of the SHB. Laboratory tests on compression assemblies demonstrated that: hex-nut loosening can be produced in the laboratory by the cyclical loading of compression assemblies; crimping of the threads of the rod prevented hex-nut back-off and loosening of the SHB; crimping of the threads of the rod with the described rod crimper applied at a 90 degree angle did not damage the core of the rod or compromise its ability to withstand cyclical or tension loads; and crimping of the threads of the rod at angles other than 90 degrees damaged the core of the rod and significantly altered its ability to withstand cyclical loading. With subsequent clinical application of these principles, failure of compression instrumentation because of loosening of the SHB seems not to have been reported in the literature.

Adult↗

PubMed1984

Interspinous process segmental spinal instrumentation.

A method for interspinous segmental spinal instrumentation (ISSI) is described and the laboratory testing and early clinical results are reported. The method utilizes a button-wire implant that is passed through the thickest and strongest part of the base of the spinous process. Tension tests show the stress-relieving qualities of the implant improve pullout strength 47% over simple wire fixation of the spinous process. Tests on the scoliosis simulator show that the interspinous instrumented spine resists high compressive loads to failure, comparing favorably with other systems tested. Early clinical experience with the implant for a wide variety of uses has been encouraging. The authors use ISSI as their procedure of choice in idiopathic and congenital scoliosis.

Adolescent↗

PubMedDate not supplied

Relationship of spine deformity and pelvic obliquity on sitting pressure distributions and decubitus ulceration.

The distribution of pressure points in 16 patients with paraplegia, nine with ulcers, and six who were ulcer free were compared with the distribution in 15 normal individuals using an instrument capable of simultaneously measuring multiple pressure points under the buttocks and thighs. The nine patients with ischial and sacral decubiti showed redistribution of their sitting pressures posteriorly, asymmetrical loading of the ischiae, and higher than normal pressures under the sacrococcygeum. These abnormal pressures were associated with unbalanced scoliosis, pelvic obliquity, and the loss of physiological lordosis following a spinal fusion. We defined four criteria of risk for decubitus ulceration.

Buttocks↗