Rotation effect and anatomic landmark accuracy for midline placement of lumbar artificial disc under fluoroscopy
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Total disc arthroplasty can be a viable alternative to fusion for degenerative disc disease of the lumbar spine. The correct placement of the prosthesis within 3 mm from midline is critical for optimal function. Intra-operative radiographic error could lead to malposition of the prosthesis. The objective of this study was first to measure the effect of fluoroscopy angle on the placement of prosthesis under fluoroscopy. Secondly, determine the visual accuracy of the placement of artificial discs using different anatomical landmarks (pedicle, waist, endplate, spinous process) under fluoroscopy.
Artificial discs were implanted into three cadaver specimens at L2-3, L3-4, and L4-L5. Fluoroscopic images were obtained at 0°, 2.5°, 5°, 7.5°, 10°, and 15° from the mid axis. Computerized tomography (CT) scans were obtained after the procedure. Distances were measured from each of the anatomic landmarks to the center of the implant on both fluoroscopy and CT. The difference between fluoroscopy and CT scans was compared to evaluate the position of prosthesis to each anatomic landmark at different angles.
The differences between the fluoroscopy to CT measurements from the implant to pedicle was 1.31 mm, p < 0.01; implant to waist was 1.72 mm, p < 0.01; implant to endplate was 1.99 mm, p < 0.01; implant to spinous process was 3.14 mm, p < 0.01. When the fluoroscopy angle was greater than 7.5°, the difference between fluoroscopy and CT measurements was greater than 3 mm for all landmarks.
A fluoroscopy angle of 7.5° or more can lead to implant malposition greater than 3 mm. The pedicle is the most accurate of the anatomic landmarks studied for placement of total artificial discs in the lumbar spine.
KeywordsArtificial disc Total disc replacement Malposition Fluoroscopic guidance Accuracy
Conflict of interest
The authors declare no conflict of interest.
- 1.McAfee PC et al (2005) A prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of lumbar total disc replacement with the CHARITE artificial disc versus lumbar fusion: part II: evaluation of radiographic outcomes and correlation of surgical technique accuracy with clinical outcomes. Spine (Phila Pa 1976) 30(14):576–583 (discussion E388-90) CrossRefGoogle Scholar
- 3.Rohlmann A et al (2013) Parameters influencing the outcome after total disc replacement at the lumbosacral junction. Part 1: misalignment of the vertebrae adjacent to a total disc replacement affects the facet joint and facet capsule forces in a probabilistic finite element analysis. Eur Spine J 22(10):2271–2278CrossRefPubMedPubMedCentralGoogle Scholar
- 5.Zigler JE, Delamarter RB (2012) Five-year results of the prospective, randomized, multicenter, Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement versus circumferential arthrodesis for the treatment of single-level degenerative disc disease. J Neurosurg Spine 17(6):493–501CrossRefPubMedGoogle Scholar
- 13.Mathews H, Eisermann L, LeHuec J, Friesem T (2005) Total disc arthroplasty using maverick total disc replacement. In: Guyer R, Zigler J (eds) Spinal arthroplasty: a new era in spine care, Chap 13. Quality Medical Publishing, St. Louis, MissouriGoogle Scholar