Influence of Previous Surgery on Outcome in IDE ProDisc-L Study

Introduction: It has been reported previously that prior surgery negatively influences the success of subsequent surgeries at the same level.

Purpose: The objective of this study was to compare patients that had any previous surgical treatment at the operative level prior to being enrolled in the IDE study to patients with no previous surgery for both treatment arms.

Study Design: A multi-center prospective, randomized clinical trial was completed to assess the safety and efficacy of the ProDisc-L prosthesis (Synthes Spine, L.P.) compared to circumferential fusion at one level from L3-S1.

Patient Sample: There was a total of 286 patients in the IDE trial.

Outcome Measures: SF-36, VAS, Oswestry Disability Index (ODI), neurologic status, radiographic ROM.

Methods: All patients were assessed pre-operatively and post-operatively at 6 weeks, 3, 6, 12, 18, and 24 months. Patients all met the inclusion/exclusion criteria to be included in the ProDisc 1-level clinical study. Patients with any prior surgery were compared to no previous surgery. Prior surgeries were then divided into discectomy, IDET, laminectomy, laminotomy, or other. Patients may have been included in one or more subgroup.

Results: All demographical measurements were the same between the three comparison groups. Those that had prior surgery was not statistically different in the randomized portion of the trial (ProDisc-L-R: 35.4%; Fusion: 30.7%) but was statistically higher in the training cases (ProDisc-L-NR: 48%). VAS and ODI results at all time points show patients with no previous surgery and patients with previous surgery were statistically better than pre-op. Within treatment groups, no statistical differences could be found for any of the primary endpoints between those with and without prior surgery.

Conclusion: This study reports Class I data. At 2 years follow-up, it does not appear that prior surgery limited to those described above negatively effects the overall success of the patient.