The Spinal Navigation Trial - Surgical Navigation or Free Hand Technique in Spine Surgery

Study Overview
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Brief Summary
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The spinal navigation trial (SPINAV) is a randomized controlled trial (RCT) evaluating the use of computer-assisted navigation in surgery for spinal deformity

Detailed Description
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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.

Official Title
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SpiNav - SPInal NAVigation Trial

Conditions
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Scoliosis, Kyphosis

Intervention / Treatment
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* Procedure: Pedicle screws insertion by free hand technique
* Procedure: Pedicle screws insertion using ARSN
* Procedure: Pedicle screws insertion using IRSN


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent by patient or legal guardian Age 12 years and older Spinal deformity surgery Exclusion Criteria: Unable to give informed consent Surgery without pedicle screws Previous surgery with pedicle screws in the planned surgical area

Ages Eligible for Study
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Minimum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Navigation group 1 ARSN<br>Augmented reality surgical navigation (ARSN). Pedicle screw placement using the Philips ClarifEye system combined with Philips Allura for imaging. | Procedure: Pedicle screws insertion using ARSN<br>* 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.<br>|
| Active Comparator: Control group 1 FH<br>Free hand (FH) surgical technique. Pedicle screw placement using conventional free hand technique. | Procedure: Pedicle screws insertion by free hand technique<br>* Spinal deformity correction. Pedicle screws are inserted using free hand technique with the help of intraoperative fluoroscopy if needed.<br>|
| Experimental: Navigation group 2 IRSN<br>Infrared surgical navigation (IRSN). Pedicle screw placement using Brainlab Curve 1.2 combined with Medtronic o-arm for imaging. | Procedure: Pedicle screws insertion using IRSN<br>* 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.<br>|
| Active Comparator: Control group 2 FH<br>Free hand (FH) surgical technique. Pedicle screw placement using conventional free hand technique. | Procedure: Pedicle screws insertion by free hand technique<br>* Spinal deformity correction. Pedicle screws are inserted using free hand technique with the help of intraoperative fluoroscopy if needed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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). | Intraoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pedicle screw intraoperative revision rates-clinical assessment | Number of screws intraoperatively revised based on clinical assessment | Intraoperative | 
| Pedicle screw intraoperative revision rates- neurophysiology | Number of screws intraoperatively revised based on neurophysiology | Intraoperative | 
| Pedicle screw intraoperative revision rates- intraoperative verification | Number of screws intraoperatively revised based on intraoperative verification CBCT scan | 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) | 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) | 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) | Intraoperative | 
| Accuracy for IRSN - angular deviation | Angular deviation of the placed screw compared to the navigated path measured on the postoperative computed tomography (CT) | 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 | 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. | Intraoperative | 
| Pedicle screw placement density | The study aims for 100% pedicle screw density. Hooks may be placed as rescue or if screw placement fails. | 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. | Preoperative and intraoperative | 
| Deformity correction change | Cobb angle change from preoperative to first erect postoperative radiograph | 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 | Intraoperative | 
| Staff radiation dose exposure | Average staff radiation exposure (in mSv) for the whole procedure | 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. | 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) | Intraoperative | 
| Intraoperative characteristics- instrumentation time | Instrumentation time (total time for navigated/FH screw placement from first to last screw placement) | Intraoperative | 
| Intraoperative characteristics- instrumentation time/level | Instrumentation time normalized to number of levels | Intraoperative | 
| Intraoperative characteristics- time for verification imaging | Time for intraoperative verification imaging (CBCT and/or Fluoroscopy) | Intraoperative | 
| Intraoperative characteristics- screw placement time | Screw placement time (per screw, from start with awl to screw placed) | Intraoperative | 
| Intraoperative characteristics- blood loss | Intraoperative blood loss | Intraoperative | 
| Inpatient stay | Length of hospital stay in days | 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) | 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) | up to 5 years | 
| Patient reported outcome measures- Oswestry Disability Index (ODI) | The back disabiliy questionnaire (ODI) ranging from 0 (best) to 100 (worst) | 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) | up to 5 years | 
| Complications | Number of patients that have had complications | At 30 days, at 90 days | 
| Revision surgery | Number of patients that have undergone revision surgeries | At 30 days, at 90 days, at 1 year | 
| Cost per patient | Cost per patient | At 30 days, at 90 days, at 1 year |