Anterior expandable strut cage replacement for osteoporotic thoracolumbar vertebral collapse

The authors investigated the usefulness of using an expandable cage strut in anterior reconstruction after osteoporotic vertebral collapse in patients with neurological deficits.

Twenty-eight patients who had undergone expandable cage strut-augmented anterior thoracolumbar reconstruction participated in a follow-up review for a mean of 4.9 years. Radiographs were reviewed for kyphosis, lateral tilt of the implant, cage subsidence, the presence of a solid fusion mass, and instrumentation failure. Changes in neurological status and visual analog scale (VAS) pain score, as well as technique-related complications, were examined. The mean angles +/- the standard deviations of kyphosis correction 4 to 6 weeks after surgery and at final follow-up examination were 10.4 +/- 7.6 degrees and 5.6 +/- 6.0 degrees, respectively. The mean subsidence of the expandable cage within the adjacent vertebrae was 2.5 +/- 3.0 mm at the final follow-up examination. Neurological improvement at the final follow up was more significant in patients with Type I (wedge-type) than Type 2 (flat-type) (p = 0.037) or Type 3 (concave-type) (p = 0.006) vertebral collapse. Follow-up VAS scores were significantly higher in patients with Type 1 than Type 3 collapse (p = 0.012). In all cases the authors observed solid union with incorporation of the cage. There were no surgery-related complications.

An expandable titanium cage strut seems useful in vertebral body replacement in patients with osteoporotic thoracolumbar collapse. Favorable results were obtained in cases of Type I collapse (wedge type) in which the middle and posterior columns remained comparatively intact.