The safety and efficacy of the Isola spinal implant system for the surgical treatment of degenerative disc disease - A prospective study

Study Design. This is a prospective study designed in consultation with and approved by the Food and Drug Administration with the purpose of determining the safety and efficacy of the Isola Spinal Implant System for the surgical treatment of patients with degenerative disc disease. Objectives. To report the results of the degenerative disc disease group from the Isola Investigational Device Exemption study,which was done to determine whether the Isola Spinal Implant System is a safe and effective treatment. Summary of Background Data. The safety and efficacy of transpedicular instrumentation as an adjunct in achieving lumbar spine fusion are still debated. Methods. Hospital Investigational Review Board approval of the study protocol was obtained at the 10 participating centers. One hundred twenty patients (49 men and 71 women; average age, 54 years [range, 25-83 years]) were enrolled. Clinical and radiographic follow-up evaluation was done using protocols established prospectively. Results. Of the 120 patients, 12 (10%) had device-related problems. There were two operative and four device-related complications after surgery. Six other patients had their implants removed either for local pain (two) or for looseness or breakage (four). Of 118 patients eligible for follow-up evaluation at 24 months, 107 (91%) were available for study. Fusion was achieved in 97 (91%) patients. Average combined function and pain scores improved by 2.6 points (P < 0.0001). Clinical success, as measured by combining function and pain scores, was achieved in 65% of the patients by the most stringent criteria and 73% by less stringent criteria. Clinical success was significantly higher in patients who had not had previous surgery than in those who had, 77% versus 57% (P = 0.04). Conclusions. The present study suggests that the Isola Spinal Implant System can be safely used, is an effective adjunct in the achievement of fusion, and yields an acceptable number of successful clinical outcomes, especially when considering the preponderance of previously operated patients included in this group.