The significance of hardware failure in anterior cervical plate fixation. Patients with 2- to 7-year follow-up

STUDY DESIGN: In this retrospective study, the incidence of anterior cervical hardware failure was reviewed in 109 patients with degenerative disorders treated by one surgeon. OBJECTIVES: To evaluate the risk of injury caused by hardware failure in anterior cervical spine reconstruction. SUMMARY OF BACKGROUND DATA: Anterior plating is used for stabilization after cervical spine trauma and other conditions of instability. There has been a concern among surgeons about the risks involved when anterior cervical plating fails (fracturing or loosening of the construct). METHODS: The series included placement of 70 nonconstrained plates and 39 constrained plates. The average length of follow-up was 43 months. Hardware failure was defined as any broken or loosened screw or plate, regardless of clinical significance. RESULTS: There were 32 Orozco (Synthes, Inc., Paoli, PA) failures, 5 cervical spine locking 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. CONCLUSIONS: The incidence of prominent hardware that endangers tracheoesophageal structures is minimal. In most cases, careful and long-term follow-up can ensure that failed hardware has not progressed and can confirm that late failure has not occurred. Hardware failure should increase the surgeon's suspicion of a nonunion, but immediate removal of the failed hardware is rarely necessary. If reoperation is necessary for nonunion repair, kyphosis correction, or other secondary procedures, the hardware can be removed at that time. Constrained systems (cervical spine locking plate, Orion) had significantly (P2 = 7.65, P < 0.01) fewer failures than the nonconstrained Orozco system.