Letter to the Editor. Augmented reality–assisted spinal instrumentation placement

Abstract Augmented reality (AR) is a novel technology for spine navigation. This tracking camera-integrated head-mounted display (HMD) represents a novel stereotactic computer navigation modality that has demonstrated excellent precision and accuracy with spinal instrumentation.1 Standard computer-assisted spine navigation systems have two major shortcomings: attention shift and line-of-sight limitations. The HMD allows visualization of the surgical field and navigation data concurrently in the same field of view.2,3 However, the use of AR in spine surgery has been limited to use for instrumentation, not for endoscopy. Fully endoscopic transforaminal interbody fusion under conscious sedation is an effective treatment option for degenerative spondylolisthesis and spinal stenosis. Although this technique has a steep learning curve, the advantages are vast, including preservation of normal tissue, smaller incisional requirement, and reduced postoperative pain, all enabling rapid recovery after surgery. As with other endoscopic spine surgeries, this procedure has a steep learning curve and requires a robust understanding of foraminal anatomy in order to safely access the disc space.4,5 However, with the introduction of AR, the safety and precision of this procedure could be greatly improved upon. In this video, we present a case of a 60-yr-old female who presented with a grade 1 spondylolisthesis and severe spinal stenosis and was treated with an L4-L5 interbody fusion. All instrumentation steps and localization for the endoscopic portion of the case were performed with assistance from the AR-HMD system. Informed written consent was obtained from the patient. The participant and any identifiable individuals consented to the publication of his/her image.

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Clinical accuracy and initial experience with augmented reality–assisted pedicle screw placement: the first 205 screws

Journal of Neurosurgery Spine ◽

10.3171/2021.2.spine202097 ◽

2021 ◽

pp. 1-7

Author(s):

Ann Liu ◽

Yike Jin ◽

Ethan Cottrill ◽

Majid Khan ◽

Erick Westbroek ◽

...

Keyword(s):

Augmented Reality ◽

Pedicle Screw ◽

Spinal Instrumentation ◽

Deformity Correction ◽

Pedicle Screws ◽

Screw Placement ◽

Pedicle Screw Placement ◽

Lower Extremity Weakness ◽

Head Mounted Display ◽

Clinical Accuracy

OBJECTIVE Augmented reality (AR) is a novel technology which, when applied to spine surgery, offers the potential for efficient, safe, and accurate placement of spinal instrumentation. The authors report the accuracy of the first 205 pedicle screws consecutively placed at their institution by using AR assistance with a unique head-mounted display (HMD) navigation system. METHODS A retrospective review was performed of the first 28 consecutive patients who underwent AR-assisted pedicle screw placement in the thoracic, lumbar, and/or sacral spine at the authors’ institution. Clinical accuracy for each pedicle screw was graded using the Gertzbein-Robbins scale by an independent neuroradiologist working in a blinded fashion. RESULTS Twenty-eight consecutive patients underwent thoracic, lumbar, or sacral pedicle screw placement with AR assistance. The median age at the time of surgery was 62.5 (IQR 13.8) years and the median body mass index was 31 (IQR 8.6) kg/m2. Indications for surgery included degenerative disease (n = 12, 43%); deformity correction (n = 12, 43%); tumor (n = 3, 11%); and trauma (n = 1, 4%). The majority of patients (n = 26, 93%) presented with low-back pain, 19 (68%) patients presented with radicular leg pain, and 10 (36%) patients had documented lower extremity weakness. A total of 205 screws were consecutively placed, with 112 (55%) placed in the lumbar spine, 67 (33%) in the thoracic spine, and 26 (13%) at S1. Screw placement accuracy was 98.5% for thoracic screws, 97.8% for lumbar/S1 screws, and 98.0% overall. CONCLUSIONS AR depicted through a unique HMD is a novel and clinically accurate technology for the navigated insertion of pedicle screws. The authors describe the first 205 AR-assisted thoracic, lumbar, and sacral pedicle screws consecutively placed at their institution with an accuracy of 98.0% as determined by a Gertzbein-Robbins grade of A or B.

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