The spinal navigation trial (SPINAV) is a randomized controlled trial (RCT) evaluating the use of computer-assisted navigation in surgery for spinal deformity
Spinal deformity is a common reason for spinal surgery at youth. In addition, the incidence of surgery for spinal deformity in older adults is increasing. Spinal deformity surgery is by far the most complex spine surgery. One complexity lies in the correct placement of implants in the severely deformed spine. Today, the most common surgical procedures for spinal deformity involve placement of screws in the vertebral pedicle in the instrumented part of the spine. This gives good bone purchase, which is important for deformity correction. The pedicle is narrow and misplaced pedicle screws can result in vascular, pulmonary or neural injuries, or inadequate bone purchase. Compared to the conventional free-hand surgical technique, which relies on the knowledge of anatomy, computer-assisted navigation using intraoperative 3D imaging has been shown to improve screw placement accuracy and reduce complications due to screw misplacements. As a consequence, navigation may also reduce the frequency of postoperative revision surgery compared to free hand. However, navigation still takes time, and is associated with higher intraoperative radiation than the free hand technique. As of yet, the majority of data in this area are based on retrospectively collected series, and some prospectively collected series, while randomized controlled trials on spinal deformity are lacking. In this randomized controlled trial the accuracy of pedicle screw placement using augmented reality surgical navigation (ARSN), infra-red surgical navigation (IRSN) and conventional free-hand technique will be investigated. Patients of age 12 years and older with spinal deformities are randomized into one of the three surgical techniques mentioned above. The primary outcome variable is pedicle screw placement accuracy at 1st attempt assessed using the Gertzbein scale. Data from the navigated groups (ASRN and IRSN) will be analyzed together, and compared with the free hand groups analyzed together. The ASRN and ISRN groups will also be compared with their respective free hand groups.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
62
Spinal deformity correction. Pedicle screws are inserted using free hand technique with the help of intraoperative fluoroscopy if needed.
Spinal deformity correction. Pedicle screws are inserted using augmented reality surgical navigation (ARSN) with the ClarifEye navigation system and the Philips Allura 2D/3D imaging system.
Spinal deformity correction. Pedicle screws are inserted using infra-red surgical navigation (IRSN) with the Brainlab Curve 1.2 navigation system combined with the Medtronic O-arm 2D/3D imaging system.
Karolinska University Hospital
Stockholm, Sweden
Accurately placed pedicle screws
The primary endpoint is the percentage of accurately placed pedicle screws assessed using the Gertzbein scale and based on intraoperative verification scan cone beam computed tomography (CBCT).
Time frame: Intraoperative
Pedicle screw intraoperative revision rates-clinical assessment
Number of screws intraoperatively revised based on clinical assessment
Time frame: Intraoperative
Pedicle screw intraoperative revision rates- neurophysiology
Number of screws intraoperatively revised based on neurophysiology
Time frame: Intraoperative
Pedicle screw intraoperative revision rates- intraoperative verification
Number of screws intraoperatively revised based on intraoperative verification CBCT scan
Time frame: Intraoperative
Accuracy for ARSN - path deviation in mm
Deviation from planned navigated path in mm at bone entry and screw tip measured on the postoperative computed tomography (CT)
Time frame: Intraoperative
Accuracy for IRSN- path deviation in mm
Deviation from navigated path in mm at bone entry and screw tip measured on the postoperative computed tomography (CT)
Time frame: Intraoperative
Accuracy for ARSN - angular deviation
Angular deviation (degrees) of the placed screw compared to the planned navigated path measured on the postoperative computed tomography (CT)
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Time frame: Intraoperative
Accuracy for IRSN - angular deviation
Angular deviation of the placed screw compared to the navigated path measured on the postoperative computed tomography (CT)
Time frame: Intraoperative
Accuracy at 1st attempt
Accuracy at 1st attempt = (Screws placed at first attempt according to intraoperative protocols and graded 0 or 1) / (total number of placed screws). Assessed on intraoperative CBCT
Time frame: Intraoperative
Final accuracy of placed pedicle screws
Final accuracy of placed pedicle screws is calculated as: number of accurately placed screws (Gertzbein grade 0+1) according to postoperative CT / total number of placed screws.
Time frame: Intraoperative
Pedicle screw placement density
The study aims for 100% pedicle screw density. Hooks may be placed as rescue or if screw placement fails.
Time frame: Intraoperative
Pedicle screw placement in relation to morphometric measurements
Pedicle diameters are measured on preoperative and intraoperative CT. Pedicle screw placement measured on intraoperative and postoperative CT.
Time frame: Preoperative and intraoperative
Deformity correction change
Cobb angle change from preoperative to first erect postoperative radiograph
Time frame: 3-6 months post-op
Patient radiation dose exposure
Patient radiation exposure (ED in mSv) for the whole procedure, Patient radiation exposure (ED in mSv) for fluoroscopy Patient radiation exposure (ED in mSv) for each CBCT
Time frame: Intraoperative
Staff radiation dose exposure
Average staff radiation exposure (in mSv) for the whole procedure
Time frame: Intraoperative
Intraoperative characteristics- procedure time
Total procedure time as well as normalized to number of spinal levels from the upper to the lower instrumented vertebra.
Time frame: Intraoperative
Intraoperative characteristics- planning time
Intraoperative planning time (from start of planning in navigation software until last screw planned) (only when treated with ARSN or IRSN)
Time frame: Intraoperative
Intraoperative characteristics- instrumentation time
Instrumentation time (total time for navigated/FH screw placement from first to last screw placement)
Time frame: Intraoperative
Intraoperative characteristics- instrumentation time/level
Instrumentation time normalized to number of levels
Time frame: Intraoperative
Intraoperative characteristics- time for verification imaging
Time for intraoperative verification imaging (CBCT and/or Fluoroscopy)
Time frame: Intraoperative
Intraoperative characteristics- screw placement time
Screw placement time (per screw, from start with awl to screw placed)
Time frame: Intraoperative
Intraoperative characteristics- blood loss
Intraoperative blood loss
Time frame: Intraoperative
Inpatient stay
Length of hospital stay in days
Time frame: Measured from day of surgery until day of discharge. Usual length of stay is less than one week, and maximum two weeks.
Patient reported outcome measures- Scoliosis Research Society 22 revised (SRS-22r)
The scoliosis specific questionnaire SRS-22r ranging from 1 (worst) to 5 (best)
Time frame: up to 5 years
Patient reported outcome measures- the 24 item Early Onset Scoliosis Questionnaire (EOSQ-24)
The scoliosis specific questionnaire EOSQ-24 ranging from 0 (worst) to 100 (best)
Time frame: up to 5 years
Patient reported outcome measures- Oswestry Disability Index (ODI)
The back disabiliy questionnaire (ODI) ranging from 0 (best) to 100 (worst)
Time frame: up to 5 years
Patient reported outcome measures- EQ-5D 3 level version (EQ-5D-3L)
The generic quality of life EQ-5D-3L index ranging from -0.59 (worst) to 1.00 (best)
Time frame: up to 5 years
Complications
Number of patients that have had complications
Time frame: At 30 days, at 90 days
Revision surgery
Number of patients that have undergone revision surgeries
Time frame: At 30 days, at 90 days, at 1 year
Cost per patient
Cost per patient
Time frame: At 30 days, at 90 days, at 1 year