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Significantly Improved Lumbar Arthroplasty Placement Using Image Guidance: Technical Note

Study Design. Technical report. Objective. To compare the accuracy of lumbar total disc arthroplasty placement using an image-guidance system (IGS) with conventional fluoroscopy. Summary of Background Data. Most disc arthroplasties are inserted and analyzed using fluoroscopy. One previous cadaveric study demonstrated beneficial, but insignificant, effects of IGS on total disc arthroplasty placement compared with conventional fluoroscopy. Methods. Patients were considered for lumbar total disc arthroplasty who had chronic discogenic low back pain unresponsive to nonoperative management for at least 6 months. Total disc arthroplasty was performed in n = 6 with IGS and in n = 14 without IGS. Implant placement was analyzed after surgery using computer software on high-resolution CT with respect to 3 parameters: 1) off-center mal-placement, 2) axial rotational mal-placement, and 3) coronal tilt. Results. Arthroplasties inserted with IGS were positioned with significantly greater accuracy than non-IGS arthroplasties with respect to all 3 parameters measured (off-center: 1.1 ± 0.3 vs. 2.3 ± 0.3 mm, P = 0.031; rotation: 88.8° ± 0.2° vs. 87.1° ± 0.4°; P = 0.0084; and tilt: 1.0° ± 0.5° vs. 2.6° ± 0.3°, P = 0.01). There was no significant difference in operating time between non-IGS controls (123 ± 5 minutes) and IGS (139 ± 10 minutes) groups (P = 0.129). Conclusion. This is the first clinical study to demonstrate significantly improved accuracy of lumbar total disc arthroplasty placement on CT using IGS compared with conventional fluoroscopy. IGS should be considered for routine use with lumbar total disc arthroplasty insertion.