#496 Improving Segmental Lordosis with a Crescent Shaped Hydraulic Expandable TLIF Cage: Safety, Efficacy and Early Clinical Outcomes

General Session: Cutting Edge Technology - Imaging Guidance

Presented by: D. Crandall

Author(s):

D.G. Crandall (1), (2)
S. Berven (3)
N. Anand (4)
A. Byrd (5)
M. Kadaba (6)
J. Revella (2)

(1) Sonoran Spine Center, Mesa, AZ, USA
(2) Sonoran Spine Research and Education Foundation, Phoenix, AZ, USA
(3) UC San Francisco, Orthopaedic Surgery, San Francisco, CA, USA
(4) Cedars-Sinai Spine Center, Spine Trauma Spine Center, Los Angeles, CA, USA
(5) Atlantic Orthopaedic Specialists, Virginia Beach, VA, USA
(6) CoAlign Innovations Inc, Brisbane, CA, USA

Abstract

Purpose: Expanding TLIF cages (EC) have the potential to improve interspace fit and fill, disc height, and segmental lordosis. This is the first report of clinical safety, efficacy, outcomes and radiographic improvement of an EC that is FDA approved for use in TLIF.

Methods: 233 consecutive adults undergoing primary or revision spinal arthrodesis were treated with TLIF using 305 crescent shaped, hydraulic EC by 4 surgeons at 4 centers. Age averaged 60 years(19-86years); Diagnoses were similarly split between deformity, degenerative, and spondylolisthesis. Levels treated: single - 177; 2 levels - 46; 3 levels - 12. Posterior fusions averaged 3.5 levels(2-9 levels). Technique: EC were placed front and center in the disc, expanded an average 3.4mm (0-6mm) to lift the anterior interspace, act as a fulcrum to increase segmental lordosis, and stabilize the interspace. Backfill bonegraft was used in all cases. Radiographs from the first 15 expandable cages were compared to matched controls with fixed cages for comparison of disc height and lordosis data.

Results: Both expandable cage and Control cage increased anterior, mid, and posterior disc height (p< 0.001) from pre-op, and increased segmental lordosis (EC p<0.001; control p=0.019). Regional lordosis was not affected in either group. EC group improved segmental lordosis, anterior and mid disc height more than control (p=0.002/0.002/0.001); EC posterior disc height also improved more than control but was not significant(p=0.14). Clinically, early complications included infection - 2, neuro deficit -0, PE - 1, loss of cage expansion height - 0. Revision surgery was required in 3 for unrelated adjacent level fractures in the thoracolumbar spine in deformity patients. For 38 patients with more than 12 months follow-up, improvement was noted in VAS: pre- 6.6, 1 year - 3.6; ODI scores improved: pre - 48.4 (P< 0.05), 1 year - 30.6(P< 0.05).

Conclusions: This study confirms the safety, efficacy, and segmental lordosis capability of a new crescent shaped hydraulic expandable TLIF cage. Early clinical outcomes suggest similar improvements with VAS and ODI as with other TLIF cages, with the advantage of increase segmental lordosis at the levels the cage was used.

Expandable Cage vs Control Cage