The effect of anterior cervical fusion on neck motion

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

To precisely measure the effect of anterior cervical fusion on neck motion.

SUMMARY OF BACKGROUND DATA

Anterior cervical decompression and stabilization procedures are successful in treating recalcitrant cervical radiculopathy and cervical myelopathy. Most assume that these "fusion" procedures result in a loss of neck motion, although changes in overall motion following anterior cervical fusion have never been precisely quantified.

METHODS

Twenty-five consecutive patients undergoing anterior cervical fusion of one to four levels underwent cervical range of motion testing in three planes using an unconstrained instrumented linkage before surgery and more than 3 months after surgery. These data were compared with that of 10 volunteers with no prior history of neck complaints. Motion data were compared between patients and volunteers, and between the patients before surgery and at last follow-up, using RMANOVA and Fisher's PLSD post hoc test.

RESULTS

Before surgery, the patients had significantly less motion than the volunteers in all directions. Following surgical fusion, patients gained a statistically significant amount of motion in all planes, although they did not achieve the motion seen among the volunteers. Gains in motion were seen among all patients, including those undergoing four-level fusions, and there was no correlation between postoperative motion and the number of levels fused.

CONCLUSIONS

Patients undergoing anterior cervical fusion have diminished neck motion compared with normal volunteers. Following surgery, they may be expected to gain motion, even when undergoing multilevel fusions. However, these patients are unlikely to regain the neck motion seen among normal individuals without neck complaints.

Reliability of a novel classification system for thoracolumbar injuries: the Thoracolumbar Injury Severity Score

STUDY DESIGN

Prospective study of 5 spine surgeons rating 71 clinical cases of thoracolumbar spinal injuries using the Thoracolumbar Injury Severity Score (TLISS) and then re-rating the cases in a different order 1 month later.

OBJECTIVE

To determine the reliability of the TLISS system.

SUMMARY OF BACKGROUND DATA

The TLISS is a recently introduced classification system for thoracolumbar spinal column injures designed to simplify injury classification and facilitate treatment decision making. Before being widely adopted, the reliability of the TLISS must be studied.

METHODS

A total of 71 cases of thoracolumbar spinal trauma were distributed on CD-ROM to 5 attending spine surgeons, including clinical/radiographic data, details of the TLISS, and a scoring sheet in which cases would be scored using the system. The surgeons were later assigned the task with the cases reordered. Intraobserver and interobserver reliability was calculated for TLISS components, total score, and surgeon's treatment decision using the Cohen unweighted kappa coefficients and Spearman rank-order correlation.

RESULTS

Interrater reliability assessed by generalized kappa coefficients was 0.33 +/- 0.03 for injury mechanism, 0.91 +/- 0.02 for neurologic status, 0.35 +/- 0.03 for posterior ligamentous complex status, 0.29 +/- 0.02 for TLISS total, and 0.52 +/- 0.03 for treatment recommendation. Respective results using the Spearman correlation were 0.35 +/- 0.04, 0.94 +/- 0.01, 0.48 +/- 0.04, 0.65 +/- 0.03, and 0.51 +/- 0.04. Surgeons agreed with the TLISS recommendation 96.4% of the time. Intrarater kappa coefficients were 0.57 +/- 0.04 for injury mechanism, 0.93 +/- 0.02 for neurologic status, 0.48 +/- 0.04 for posterior ligamentous complex status, 0.46 +/- 0.03 for TLISS total, and 0.62 +/- 0.04 for treatment recommendation. Respective results using the Spearman correlation were 0.70 +/- 0.04, 0.95 +/- 0.02, 0.59 +/- 0.05, 0.77 +/- 0.04, and 0.59 +/- 0.05.

CONCLUSIONS

The TLISS has good reliability and compares favorably to other contemporary thoracolumbar fracture classification systems.