THE SIGNIFICANCE OF HARDWARE FAILURE IN ANTERIOR CERVICAL PLATE FIXATION - PATIENTS WITH 2-YEAR TO 7-YEAR FOLLOW-UP

Study Design. In this retrospective study, the incidence of anterior c ervical hardware failure was reviewed in 109 patients with degenerativ e disorders treated by one surgeon. Objectives. To evaluate the risk o f injury caused by hardware failure in anterior cervical spine reconst ruction. Summary of Background Data. Anterior plating is used for stab ilization after cervical spine trauma and other conditions of instabil ity. There has been a concern among surgeons about the risks involved when anterior cervical plating fails (fracturing or loosening of the c onstruct), Methods. The series included placement of 70 nonconstrained plates and 39 constrained plates, The aver age length of follow-up wa s 43 months. Hardware failure was defined as any broken or loosened sc rew or plate, regardless of clinical significance. Results. There were 32 Orozco (Synthes, Inc., Paoli, PA) failures, 5 cervical spine locki ng plate failures, and 2 Orion (Sofamor Danek USA, Inc., Memphis, TN) failures. There were no injuries to tracheoesophageal or neurovascular structures as a result of hardware implantation or failure. Conclusio ns. The incidence of prominent hardware that endangers tracheoesophage al structures is minimal. in most cases, careful and long-term follow- up can I-ensure that failed hardware has not progressed and can confir m that late failure has not occurred. Hardware failure should increase the surgeon's suspicion of a non-union, but immediate removal of the failed hardware is rarely necessary. If reoperation is necessary for n onunion repair, kyphosis correction, or other secondary procedures, th e hardware can be removed at that time. Constrained systems (cervical spine locking plate, Orion) had significantly (P-2 = 7.65, P < 0.01) f ewer failures than the nonconstrained Orozco system.