360-Degree Complex Primary Reconstruction Using Porous Tantalum Cages for Adult Degenerative Spinal Deformity

Abstract

Study design: Retrospective cohort study.

Objective: To assess both implant performance and the amount of correction that can be achieved using multilevel anterior lumbar interbody fusion (ALIF).

Methods: Retrospective cohort study (n = 178) performed over a 4-year period. Surgical variables examined included blood loss, operative time, perioperative complications, and secondary/revision procedures. Follow-up radiographic assessment was performed to record implant-related problems. Radiographic parameters were examined pre- and postoperatively. Health-related quality of life (HRQOL) outcome measures were collected preoperatively and at 6 weeks, 6 months, 1 year, and 2 years postoperatively. Descriptive and comparative statistical analysis, using paired-sample t test and repeated-measures analysis of variance (rANOVA), was performed.

Results: Lumbar lordosis increased from 42° ± 17° preoperatively to 55° ± 11° postoperatively (P < .001). The visual analog scale back pain mean score improved from 8.3 ± 1.5 preoperatively to 2.6 ± 2.4 at 2 years (P < .001). The mean Oswestry Disability Index improved from 69.5 ± 21.5 preoperatively to 19.9 ± 15.2 at 2 years (P < .001). The EQ-5D mean score improved from 0.2 ± 0.2 preoperatively to 0.8 ± 0.1 at 2 years (P = .02). There were no neurological, vascular, or visceral approach-related injuries reported. No rod breakages and no symptomatic nonunions occurred. There was one revision procedure performed for fracture.

Conclusions: The use of porous tantalum cages as part of a 360-degree fusion to treat adult degenerative spinal deformity has been demonstrated to be a safe and effective strategy, leading to good clinical, functional, and radiographic outcomes in the short term.

Keywords: ALIF; deformity; degenerative; interbody cage; lumbar; tantalum; trabecular metal.

Figure 1.

Zimmer TM-400 implant used for anterior lumbar interbody fusion (ALIF) as part of a 2-stage 360-degree lumbar spondylodesis in this case series.

Figure 2.

A revision L5/S1 anterior lumbar interbody fusion (ALIF) was performed on a patient with rheumatoid arthritis and advanced systemic disease, who sustained a sacral fracture and tantalum cage subsidence after a fall following her index procedure.

Figure 3.

A 62-year-old woman with prior 2-stage deformity correction, presenting 2 years postoperatively with significant junctional pain and signs of proximal junctional failure. This diagnosis was supported by an obvious stress response on SPECT/CT fusion imaging highlighted by increased radiotracer activity at the proximal junctional region. Note a lack of tracer uptake at prior anterior lumbar interbody fusion (ALIF) levels suggesting stable osseous integration of the porous tantalum cages.