Matthew F. Philips

The rotating pole test: evaluation of its effectiveness in assessing functional motor deficits following experimental head injury in the rat

Neurological motor dysfunction is often an integral component of the neurological sequelae of traumatic brain injury (TBI). In experimental TBI, neurological motor testing is an outcome measure used to monitor severity of injury, and the response to treatment. This study evaluates the effectiveness and sensitivity of the rotating pole test (RP) to characterize and evaluate the temporal course of motor deficits after lateral fluid percussion (FP) injury to the rat brain. The results are compared with the previously characterized and widely used composite neuroscore of motor function (NS). The animals were required to walk across an elevated wooden pole that was either stationary or rotating to left or right directions at different speeds. Male Wistar rats underwent lateral FP injury of moderate severity (mean 2.4 atm, n = 9) or sham surgery (n = 9), and were tested at 48 h and 7 days post-injury using the NS and RP. The results of the NS directly correlated to the results of the RP, showing a significant injury effect at both 48 h and 7 days. This is the first study to show that the RP-test detects neurological motor deficits after lateral FP injury, and suggests that this technique is a reliable behavioral tool for evaluating neurological motor function in the acute period after experimental TBI.

Results and Risk Factors for Anterior Cervicothoracic Junction Surgery

OBJECT Stabilization of the cervicothoracic junction (CTJ) requires special attention to the operative approach and biomechanical requirements of the fixation construct. In this study the authors assess the morbidity associated with the anterior approach to the CTJ and define risks that may lead to construct failure after anterior CTJ surgery. METHODS Data obtained for 14 patients (six men and eight women, mean age 50.1 years) who underwent surgical stabilization of the CTJ via an anterior cervical approach were retrospectively reviewed to assess the anterior approach-related morbidity and the risks of construct failure. The mean follow-up period was 21.1 months. Four patients (29%) had previously undergone CTJ surgery; in 11 patients (64%) more than one motion segment was involved (two levels, six patients; three levels, four patients; four levels, one patient); allograft was placed in three (21%) of 14 graft sites; and anterior plates were used for reconstruction augmentation in eight patients (57%). Postoperatively all patients improved, although four patients had residual deficits or pain. Graft/plate failure, requiring surgical revision and/or halo placement, occurred in five patients (36%). One patient experienced transient recurrent laryngeal nerve palsy. Postoperatively, the authors classified patients into one of two groups: those in whom surgery was successful (nine cases) and those in whom it had failed (five cases). Analysis of the characteristics of these two groups revealed that male sex (p < 0.0365), multiple levels of involvement (p < 0.0378), and the use of allograft as compared with autograft (p < 0.0088) were significant risk factors for construct failure. Prior CTJ surgery (p < 0.053) tended to be associated with graft failure. CONCLUSIONS Findings of this study, in the setting of these factors, indicate that anterior reconstruction alone may not meet the biomechanical needs of this spinal region and that supplementary fixation may be considered to augment stabilization for fusion success.