THE EFFECTIVENESS OF THE CERVICAL HALO - OPEN VERSUS CLOSED RING - A PRELIMINARY-REPORT

The halo cervical orthosis has proven extremely effective in stabilizi ng the spine, both non-operatively and as a supplement to operative pr ocedures. Current designs of the available halo utilize either a close d or an open stabilizing ring. Twenty-four patients with various indic ations for halo application are reviewed. Eleven were treated with a c losed ring apparatus (Ace Medical, Los Angeles, California), and thirt een with an open ring device (Bremer, Inc, Jacksonville, Florida). X-r ays of the treated patients were compared by group, and patients were interviewed regarding their complaints while wearing the halo. Rates o f complication were compared. Results showed no significant difference s between radiographs (kyphosis or translation) throughout the follow- up period. Patients experienced a significantly higher incidence of ha lo-associated pain in the open group. Otherwise, there were no statist ical differences in the complication rates of either device. Whether o r not the higher incidence of pain in the open group is related to dec reased device rigidity is unknown. The open design may theoretically p ermit bending and opening of the ring to occur, the so-called 'wishbon e' effect. Based on these data, it cannot be determined whether the ad vantages of the open ring - ease of application - are offset by this p otential disadvantage. Clearly, a larger, randomized prospective study is required to investigate this.