Safety of a novel modular cage for transforaminal lumbar interbody fusion − clinical cohort study in 20 patients with degenerative disc disease

Abstract

Introduction: Transforaminal lumbar interbody fusion (TLIF) is used to reconstruct disc height and reduce degenerative deformity in spinal fusion. Patients with osteoporosis are at high risk of TLIF cage subsidence; possibly due to the relatively small footprint compared to anterior interbody devices. Recently, modular TLIF cage with an integral rail and slot system was developed to reduce cage subsidence and allow early rehabilitation.Objective: To study the safety of a modular TLIF device in patients with degenerative disc disorders (DDD) with regard to surgical complications, non-union, and subsidence.Methods: Patients with DDD treated with a modular TLIF cage (Polyetheretherketone (PEEK), VTI interfuse S) were analysed retrospectively with one-year follow-up. Lumbar sagittal parameters were collected preoperatively, postoperatively and at one year follow-up. Cage subsidence, fusion rate, screw loosening and proportion of endplate coverage were assessed in computed tomography scan.Results: 20 patients (age 66 ± 10 years, 65% female, BMI 28 ± 5 kg/m2) with a total of 37 fusion levels were included. 15 patients had degenerative spondylosis and 5 patients had degenerative scoliosis. The cages covered >60% of the vertebral body diameters. Lumbar lordosis angle and segmental disc angle increased from 45.2 ± 14.5 and 7.3 ± 3.6 to 52.7 ± 9.1 and 10.5 ± 3.5 (p = 0.029 and 0.0002) postoperatively for each parameter respectively without loss of correction at one year follow up. One case of deep postoperative infection occurred (5%). No cage subsidence occurred. No non-union or screw loosening occurred.Conclusions: The modular TLIF cage was safe with regard to subsidence and union-rate. It restored and maintained lumbar lordosis angle, segmental disc angle and disc height, which can be attributed to the large footprint of this modular cage.

Pars interarticularis repair using pedicle screws and laminar hooks fixation technique in patients with symptomatic lumbar spondylolysis

“…L5 followed by L4 vertebrae are usually the most commonly affected levels [ 14 ]. Spinal fusion was frequently used as a surgical treatment for spondylolysis even if not accompanied by spondylolisthesis or degenerative disc disease [ 15 , 16 ]. However, the technique has well-known drawbacks such as loss of mobile spinal segment and affection of adjacent level [ 17 , 18 ].…”

Do the positioning variables of the cage contribute to adjacent facet joint degeneration? Radiological and clinical analysis following intervertebral fusion

“…In our study, most of the cage positions were near the midline. Other studies pointed out that a large cage contributes to the recovery and maintenance of lumbar lordosis, segmental lordosis, and disc height (20)(21)(22).…”