Surgical treatment of osteoporotic degenerative spinal deformity with expandable pedicle screw fixation: 2-year follow-up clinical study.

Background: Osteoporotic bone offers poor purchase for the instrumentation in patients with degenerative spinal deformity (DSD), which could lead to several complications. Recently, augmentation methods to improve pedicle screw fixation have been proposed. This retrospective study was to investigate the clinical and radiographic outcomes of expandable pedicle screws (EPS) in patients with osteoporotic DSD.

Hypothesis: Expandable pedicle screws (EPS) provide excellent instrument fixation in patients with osteoporotic DSD, improving radiographic and clinical outcomes.

Materials And Methods: A total of 27 (6 males and 21 females) DSD patients who underwent orthopedics operation with EPS were retrospectively studied. Full-length standing spinal radiographs were obtained in all patients pre- and postoperatively and again at the two-year follow-up. The functional evaluations before operation and at two-year follow-up were graded with Scoliosis Research Society outcomes instrument-22 (SRS-22) and Oswestry Disability Index (ODI) scoring system.

Results: All patients obtained good corrective outcomes on spinal deformity. The preoperative ODI score was 36.7% and reduced to 11.9% at two-year follow-up (p=0.0000). Before operation, the SRS-22 function, pain, appearance and mental scores were 2.7±0.4, 3±0.6, 2.7±0.5 and 2.9±0.6, respectively. The scores at two-year follow-up were significantly improved to 3.8±0.7, 4.2±0.6, 4.3±0.6 and 4.4±0.7, respectively (p=0.0000). The SRS-22 satisfaction score was 4.6±0.4 at two-year follow-up. No instances of screw breakage, loosening or pullout in any patient at follow-up.

Discussion: EPS provides excellent instrument fixation in patients with osteoporotic DSD, improving radiographic and clinical outcomes at two years' follow-up.

Type Of Study: Retrospective case series study.

Level Of Evidence: IV.