Dynamic interspinous stabilization in lumbar discectomy: 4-year follow-up

Semirigid posterior stabilization is an alternative, avoiding arthrodesis in operated segments. However, this results in the need for dynamic stabilization to allow a stable feature function.

We conducted a prospective longitudinal self-reported interventional study. We included 46 patients with dynamic Dallostype interspinous stabilization between 1997 and 2004. A 4-year follow-up analysis was performed using clinical and radiographic studies, preoperatively and 4 years later evaluating lumbar disability, pain, disc height, disc angle (neutral, flexion, and extension). Descriptive statistics were used along with Wilcoxon signed range test. Statistical significance was accepted when p < 0.05.

Of 46 patients, 39 completed a 4-year follow-up. Included in the study were nine females and 30 males with an average age of 30.74 years. Affected levels were L4 and L5 (21 patients); L5/S1 (17 patients) and L3/L4 (one patient). An improvement was reported of 80.3% according to the Oswestry scale (p = 0.0001). Preoperative pain decreased 6.8 points VAS. Disc height decreased 0.1 mm on average without significance. Disc angle (neutral) increased 1.13° without statistical difference. For flexion the increase was 2.641° (p = 0.0002), and extension decreased 0.817° on average without statistical significance. Range of mobility decreased 3.416° (p = 0.004).

Interspinous ligamentoplasty improves segmental stability, allowing mobility within normal ranges and preserving disc height at 4 years of follow-up, as well as offering greater dynamic stability. Successful clinical improvement was demonstrated.