Abstract
Patients with multisegmental degenerative disc disease (DDD) resistant to conservative therapy are typically treated with either fusion or non-fusion surgical techniques. The two techniques can be applied at adjacent levels using Dynesys (Zimmer GmbH, Winterthur, Switzerland) implants in a segment-by-segment treatment of multiple level DDD. The objective of this study was to evaluate the clinical and radiological outcome of patients treated using this segment-by-segment application of Dynesys in some levels as a non-fusion device and in other segments in combination with a PLIF as a fusion device. A consecutive case series is reported. The sample included 16 females and 15 males with a mean age of 53.6 years (range 26.3-76.4 years). Mean follow-up time was 39 months (range 24-90 months). Preoperative Oswestry disability index (ODI), back- and leg-pain scores (VAS) were compared to postoperative status. Fusion success and system failure were assessed by an independent reviewer who analyzed AP and lateral X-rays. Back pain improved from 7.3 +/- 1.7 to 3.4 +/- 2.7 (p < 0.000002), leg pain from 6.0 +/- 2.9 to 2.3 +/- 2.9 (p < 0.00006), and ODI from 51.6 +/- 13.2% to 28.7 +/- 18.0% (p < 0.00001). Screw loosening occurred in one of a total of 222 implanted screws (0.45%). The results indicate that segment-by-segment treatment with Dynesys in combination with interbody fusion is technically feasible, safe, and effective for the surgical treatment of multilevel DDD.