Biomedical subjects

Setti S Rengachary

Publications and source records attributed to Setti S Rengachary.

5 recordsLinked to original sources

PubMed2005

Biomechanical comparison of two stabilization techniques of the atlantoaxial joints: transarticular screw fixation versus screw and rod fixation.

OBJECTIVE: To compare the biomechanical stability imparted to the C1 and C2 vertebrae by either transarticular screw fixation (TSF) or screw and rod fixation (SRF) techniques in a cadaver model. METHODS: Ten fresh ligamentous human cervical spine specimens were harvested from cadavers. The specimens were tested sequentially in the intact state, after injury and stabilization (unilateral left side and bilateral), and after fatiguing to 5000 cycles (0.5 Hz) at +/-1.0 N.m of flexion and extension. The specimens were stabilized by use of TSF in 5 spines or SRF in the other 5 spines. The data were converted to angular displacements, and the stabilized cases were compared with intact states for evaluating the efficacies of the two techniques in stabilizing the C1-C2 segments. RESULTS: In the TSF group, the unilateral fixation using one screw imparted a significant stability in only the axial rotation mode. The unilateral procedure in the SRF group was effective in stabilization in all modes except in extension. The bilateral procedure in both of the groups was effective across the C1-C2 segment. However, the SRF group afforded higher stability than the corresponding TSF group in the flexion and extension modes. The degree of stability did not change after fatigue compared with the prefatigue data. CONCLUSION: In general, a surgeon should undertake a bilateral fixation to achieve sufficient stability across the atlantoaxial complex, and either technique will provide satisfactory results, although the SRF technique may be better in the flexion and extension modes. One should use the SRF procedure while trying to achieve stability with a unilateral system.

Aged↗

PubMed2002

Bone healing and spinal fusion.

Bone is a tissue that constantly undergoes deposition, resorption of stromal matrix, and remodeling. These processes may be altered by a variety of chemical, mechanical, cellular, and pathological mechanisms. Understanding the physiology of bone healing and the mechanisms affecting this process is important not only when evaluating normal skeletal development but also when initiating fracture repair. Because the ultimate success of spinal fusions involves creation of an osseous union, we focus this review on the anatomy and physiology of bone under physiological conditions, normal bone healing and mechanisms that alter it, and available adjuvant therapies that may enhance healing potential in a clinical setting.

Animals↗

PubMed2002

Bone morphogenetic proteins: basic concepts.

The cellular and molecular events governing bone formation in the embryo, healing of a fractured bone, and induced bone fusion follow a similar pattern. Discovery, purification, and recombinant synthesis of bone morphogenetic proteins (BMPs) constitute a major milestone in the understanding of bone physiology. In this review the author discusses the mechanism of action, clinical applications, dosage, and optimum carriers for BMPs. The roles played by other growth factors are also discussed.

Animals↗

PubMed2002

Black disc disease: a commentary.

Internal disc disruption associated with axial back pain but not radicular pain is a disease entity that was recognized about two decades ago as a disorder that could potentially be treated by spinal fusion. In this article the authors describe the clinical syndrome, magnetic resonance imaging and discography findings of pathophysiological pain generation, and the available surgical options. Based on the current understanding of this disease entity, the optimum surgical procedure entails radical discectomy, anterior column support, adequate amounts of auto- or allograft bone, bone extenders and enhancers, and rigid stabilization of the motion segment.

Back Pain↗

PubMed2002

Reduction of spondylolisthesis.

In this article the authors discuss the syndrome of isthmic spondylolisthesis occurring at the lumbosacral junction in adults, providing a description of the clinical syndrome, altered biomechanics, and imaging characteristics. The authors pose arguments in favor of reduction and instrument-assisted fusion. Their surgical technique is detailed. They describe transsacral interbody fusion in which fibular allograft and in situ fixation are used, which they consider the second-best alternative technique when attempts at reduction fail.

Biomechanical Phenomena↗