Study design: Prospective, two-way complete block design analyzing facial contact pressures during prone positioning with the use of cervical traction for spinal surgery. Level 2 evidence.
Objective: To assess the effect of varying traction angle and traction weight to limit facial contact pressure.
Summary of background data: Posterior spine surgery has known hazards related to the prone positioning. Cervical traction is used to limit downward pressure exerted to the face to stabilize the head and neck and to aide in deformity correction. The effects of the traction angle and force on facial contact pressure have not been studied.
Methods: Facial contact pressure was measured for 10 patients undergoing posterior spine surgery in the prone position with Gardner-Wells tongs applied for cervical traction. The facial contact pressure was measured with a force transducer at each of three angles from horizontal (0°, 30°, 45°) and each of four traction weights (0, 5, 10,15 lb), a total of 12 measurement parameters for each patient. An in-line tensiometer provided consistent application of force throughout the traction system.
Results: Ten patients, average age 15 ± 0.6 years, six female, BMI 21.3 ± 1.7, underwent facial pressure monitoring. Post hoc analysis showed that both higher traction weights and angles significantly limited facial pressure (P = 0.0001). The lowest overall average facial pressure of 0.51 lb (95% CI = 0.28-0.73) occurred with 15 lb of traction applied at 45° above the horizontal. This was significantly less facial pressure than found when traction was applied at all weights tested using the commonly employed 0° in-line traction angle (P < 0.0001).
Conclusion: A combination of upward vectored 45° traction angle and 15 lb of weight significantly decreased facial contact pressure. The use of an "in-line tensiometer" assured an accurate force application.