94 - A Prospective Study of an Acid Etched Surface Titanium Implant for the...

#94 A Prospective Study of an Acid Etched Surface Titanium Implant for the Treatment of Lumbar Degenerative Pathology; Clinical and Radiographic Outcomes with 2 Year Follow up

Lumbar Therapies and Outcomes

Poster Presented by: P. Slosar

Author(s):

P.J. Slosar (1)
A. Cabalo (2)
J.B. Reynolds (1)
N. Goldthwaite (1)

(1) Spine Care Medical Group, San Francisco Spine Institute, Daly City, CA, USA
(2) Kaiser Permanente, Orthopedic Surgery, Wailuka, HI, USA

Abstract

Background: Lumbar interbody arthrodesis is performed by inserting an implant into the disc space. Titanium (Ti) was used in the past but clinical results were variable and their used declined. Basic science studies find acid etching the surface of Ti induces better osteoblast differentiation than PEEK and stimulates physiologic BMP production which may facilitate bone integration with the implant surfaces.[1]

Purpose: Assess the safety, efficacy, clinical and radiographic outcomes of patients who have undergone anterior lumbar interbody fusions with a unique titanium implant. This is the first clinical study to assess this technology.

Methods: Prospective consecutive enrollment and data collection was completed on all eligible patients undergoing ALIF at 1-3 lumbar spinal segments between 2008-2010. Surgical technique: mini-open anterior retroperitoneal approach (vascular surgeon) ALIF interbody cage (Titan Spine) + Infuse (Medtronic) 3 mg/ cage. Pedicle screw fixation/ decompression performed at the discretion of the spinal surgeon. Visual Numerical Scale (VNS) and Oswestry Disability Index (ODI) scores were collected pre, 6, 12, and 24 months post-op. Fusion was determined by independent radiologist review of X-rays and CT scans.

Results: 77 patients 42 male and 35 female. Ave age 46 years (range 23-67).

Diagnosis: DDD n= 52(67%) Spondylolisthesis n=19 (25%); Nonunion n=6 (8%). 48 (63%) had ALIF + decompression + pedicle screw fixation, 24 (31%) had ALIF + percutaneous pedicle screw fixation, 5 patients (6%) had stand-alone ALIF. VNS and ODI scores improved significantly at 6, 12, and 24 months. Clinical outcomes at 6 months were statistically unchanged at 12 and 24 months. The open and percutaneous groups demonstrated similar outcomes with a trend towards less pain and better function in the percutaneous group. A total of 138 spinal segments levels were fused. Radiographic analysis revealed 97% fusion rate between 6-12 months and no appreciable subsidence. 1 case of retrograde ejaculation (2.3%) resolved by 3 months.

Conclusions: This study confirms that a high degree of clinical success can be obtained in patients undergoing a spinal fusion with a primary diagnosis of DDD/ Discogenic lumbar pain. High fusion rates can be obtained with minimal complications by performing ALIF with an acid etched Ti implant combined with BMP. Meaningful Clinical

Improvements (ODI ≥15 and VNS ≥3) were achieved in the majority of cases. Interestingly, the clinical outcomes at 12 and 24 months were not significantly different than the 6 month. This is postulated to be due to early bone incorporation at the implant surface and lack of subsidence. The results demonstrate that this Ti implant is safe and effective in achieving rapid and sustainable clinical outcomes. Further study is underway to determine the most cost effective biologic that may be used without sacrificing clinical results.

[1] Osteoblasts exhibit a more differentiated phenotype and increased bone morphogenetic protein production on titanium alloy substrates than on PEEK. R Olivares-Navarrete, et al.; The Spine Journal 12(2012) 265.

Clinical Outcomes