CORRELATION OF CLINICAL, RADIOGRAPHIC, AND SURGICAL LOCALIZATION OF INTERVERTEBRAL DISC EXTRUSION IN SMALL-BREED DOGS - A PROSPECTIVE-STUDYOF 50 CASES

Objective - To compare prospectively clinical, radiographic, and surgi cal findings of intervertebral disc extrusion (IDE) localization in sm all-breed dogs and to determine the best means of lesion localization for the purpose of hemilaminectomy. Study Design - Clinical, radiograp hic, and surgical findings of small-breed dogs with thoracolumbar IDE were prospectively compared for agreement on lesion localization. Samp le Population - 50 small-breed dogs with IDE treated at the three part icipating veterinary hospitals were included in the study if no other confounding diseases were identified and if the owner grave permission for diagnostic tests and surgery. Methods - Clinical and surgical fin dings were recorded by the surgeon assigned to the case. Radiographic studies were evaluated independently by two radiologists blinded as to the clinical and surgical findings. kappa values and 95% confidence i ntervals were calculated for agreement on lesion localization by clini cal, radiographic, and surgical means and for agreement between radiol ogists. Results - kappa values for agreement of lesion localization we re as follows: clinical versus surgical, 0.595; radiologist A versus r adiologist B, 0.81; radiologist A versus surgical findings, 0.60; radi ologist B versus surgical findings, 0.71. Both radiologists' interpret ation of IDE localization agreed with surgical localization in 60% of cases. Conclusions - Clinical lateralization of IDE was found to be th e least reliable factor of those studied for determining on which side the hemilaminectomy should be performed. Results of this study differ from those of previous studies examining the reliability of myelograp hy to localize the site of IDE accurately. The results of this study f urther suggest that surgery may not be an absolute standard for determ ination of the localization of IDE in small-breed dogs.Clinical Releva nce - Intervertebral disc extrusion in small-breed dogs frequently res ults in bilateral distribution of extruded material. Computed tomograp hy or magnetic resonance imaging may be necessary to delineate complet ely the distribution of extruded disc material in IDE. (C) Copyright 1 998 by The American College of Veterinary Surgeons.