Effect of bone graft granule volume on postoperative fusion after lumber spinal internal fixation: A retrospective analysis of 82 cases

Systematic review and meta-analysis for the impact of rod materials and sizes in the surgical treatment of adult spine deformity

PURPOSE

To assess clinical and safety outcomes associated with different rod materials and diameters in adult spinal deformity (ASD) surgery.

METHODS

A systematic literature review and meta-analysis evaluated ASD surgery using pedicle screw fixation systems with rods of different materials and sizes. Postoperative outcomes (i.e., Cobb, sagittal vertical axis, and pelvic tilt angle) and complications (i.e., pseudarthrosis and rod breakage) were assessed. Random effects models (REMs) pooled data for outcomes reported in ≥ 2 studies.

RESULTS

Among 50 studies evaluating ASD surgery using pedicle screw fixation systems, 17 described rod material/diameter. Postoperative outcomes did not statistically differ between cobalt-chromium (CoCr) vs. titanium (Ti) rods (n = 2 studies; mean [95% confidence interval (CI)] sagittal vertical axis angle: CoCr 37.00° [18.58°-55.42°] and Ti 32.58° [24.62°-40.54°]; mean [95% CI] pelvic tilt angle: CoCr 26.20° [22.87°-29.53°] and Ti 20.15° [18.0°-22.31°]). The pooled proportion (95% CI) of pseudarthrosis was 15% (7-22%) for CoCr and 12% (- 8-32%) for stainless steel (SS) (n = 2 studies each; Chi2 = 0.07, p = 0.79). The pooled proportion (95% CI) of broken rods was 12% (1-22%) for Ti (n = 3 studies) and 10% (2-19) for CoCr (n = 1 study). Among 6.0-6.35 mm rods, the pooled (95% CI) postoperative Cobb angle (n = 2) was 12.01° (9.75°-14.28°), sagittal vertical axis angle (n = 4) was 35.32° (30.02°-40.62°), and pelvic tilt angle was 21.11° (18.35°-23.86°).

CONCLUSIONS

For ASD patients undergoing posterior fixation and fusion, there are no statistically significant differences in postoperative outcomes or complications among rods of varying materials and diameters. Benchmark postsurgical outcomes and complication rates by rod material and diameter are provided.

LEVEL OF EVIDENCE

III.

Anatomical characteristics affecting the surgical approach of oblique lateral lumbar interbody fusion: an MR-based observational study

Background

Oblique lateral lumbar interbody fusion (OLIF) is one of the most widely used lumbar interbody fusion procedures in clinical practice. The aim of this study was to minimize the incidence rate of surgical complications by measuring the anatomical parameters of structures surrounding the working channels of OLIF with 3D COSMIC sequence.

Methods

The MRI examination included conventional MRI sequence and 3D COSMIC sequence. Surgical window, psoas thickness, the transverse diameter of the endplate, and nerve distance were measured to evaluate the anatomical characteristics surrounding the OLIF working channels.

Results

The widths of the natural surgical window at the level of the L2–3, L3–4, and L4–5 intervertebral measured in this study were 16.25 ± 4.22, 15.46 ± 4.64 mm, and 11.71 ± 6.29 mm, respectively. The average thickness of the left psoas major muscle at the level of L2–3, L3–4, and L4–5 intervertebral space was 28.42 ± 5.08 mm, 30.76 ± 5.84 mm, and 31.16 ± 7.72 mm, respectively. The mean value of insertion angle (β) was 45.57° ± 6.19° in L2–3 intervertebral space, 49.90° ± 6.53° in L3–4 intervertebral space, and 43.34° ± 8.88° in L4–5 intervertebral space.

Conclusions

The 3D COSMIC sequences can be used for imaging anatomical assessment before OLIF surgery. In preoperative planning, the 3D COSMIC sequence can be used to measure the relevant parameters mentioned above to optimize the planned surgical approach.