Lightning Podiums: Spinal Potpourri - 803B

Presented by: M. Mokawem

Author(s):

M. Mokawem(1), R. Lee(1), C. Harman(1)

(1) Royal National Orthopaedic Hospital, Spinal Surgery, Stanmore, United Kingdom

Abstract

Introduction: The use of lumbar interbody cages in minimally invasive adult deformity and degenerative surgery allows restoration of sagittal and coronal balance, provides neural decompression (indirect and direct) and can achieve a 360-degree fusion. Successful long-term outcomes are dependent on achieving a solid fusion. This is dependent on cage material, cage design, bone graft used as well as surgical technique. Moreover, it is harder to achieve fusion in multilevel surgery. We present a case series of 78 patients who had a combination of either transforaminal or lateral interbody 3D printed lamellar titanium cages packed with silicate substituted calcium phosphate bone graft. No iliac crest bone graft was harvested. We achieved a 99 % fusion rate at 12 months.

Materials and Methods: This study is a review of prospectively collected data from a single surgeon consecutive case series of 78 adult patients with lumbar degenerative disease or deformity requiring anterior column reconstruction. Transforaminal Lumbar Interbody Fusion (TLIF) and Lateral Lumbar Interbody Fusion (LLIF) cases were included. All cases had 3D printed lamellar titanium cages with silicate substituted calcium phosphate bone graft. All patients had their reconstruction augmented with posterior instrumentation or a lateral plate.

Outcome Measures: 1. Radiological: All patients had CT scans at 12 months to assess fusion. CT scans were reported by a consultant musculoskeletal radiologist and independently reviewed by both authors. 2. Patient reported: EuroQol-5Dimension (EQ-5D), EQ-5D Visual Analogue Scale (VAS), VAS Leg Pain, VAS Back Pain and Oswestry Disability Index (ODI) were collected at 6 weeks, 6 months and 1 year.

Results: Case mix was as follows: 25 single level TLIF (14 cases at L4/5, 10 at L5/S1, 1 at L2/3), 14 two level TLIFs (6 cases at L3/4 and L4/5 and 8 cases at L4/5 and L5/S1), 39 LLIF cases with 79 cages (11 cages at L1/2, 22 cages at L2/3, 30 cages at L3/4 and 16 cages at L4/5). 12 Patients had two lateral cages inserted and 10 patients had 3 or more lateral cages in the correction of degenerative scoliosis. CT scans showed solid fusion in all but one case with good integration of the cage at the vertebral body interface and no evidence of screw loosening. The one case of pseudoarthrosis was in a two level TLIF in a grade 2 spondylolisthesis with fusion at L4/5 and pseudoarthrosis at L5/S1. Patient reported outcomes showed significant improvements at 1 year.

Conclusion: Our study demonstrates that excellent fusion rates can be achieved with 3D printed lamellar titanium cages and silicate substituted calcium phosphate bone graft even where multilevel interbody cages are used. We believe that the excellent fusion rates significantly contribute to the improvement in patient reported outcomes. The increased cost of the bone graft compared to autologous bone graft is justified due to the increased rate of fusion and the decreased morbidity.

Table of Patient Reported Outcomes