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

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

Scoliosis

Kyphosis

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.

Pedicle screws insertion by free hand technique

Pedicle screws insertion using ARSN

Pedicle screws insertion using IRSN

SpiNav - SPInal NAVigation Trial

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).

Professor

Number of screws intraoperatively revised based on clinical assessment

Number of screws intraoperatively revised based on neurophysiology

Number of screws intraoperatively revised based on intraoperative verification CBCT scan

Deviation from planned navigated path in mm at bone entry and screw tip measured on the
postoperative computed tomography (CT)

Deviation from navigated path in mm at bone entry and screw tip measured on the
postoperative computed tomography (CT)

Angular deviation (degrees) of the placed screw compared to the planned navigated path
measured on the postoperative computed tomography (CT)

Angular deviation of the placed screw compared to the navigated path measured on the
postoperative computed tomography (CT)

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

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.

The study aims for 100% pedicle screw density. Hooks may be placed as rescue or if screw
placement fails.

Pedicle diameters are measured on preoperative and intraoperative CT. Pedicle screw
placement measured on intraoperative and postoperative CT.

Cobb angle change from preoperative to first erect postoperative radiograph

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

Average staff radiation exposure (in mSv) for the whole procedure

Total procedure time as well as normalized to number of spinal levels from the upper to
the lower instrumented vertebra.

Intraoperative planning time (from start of planning in navigation software until last
screw planned) (only when treated with ARSN or IRSN)

Instrumentation time (total time for navigated/FH screw placement from first to last
screw placement)

Instrumentation time normalized to number of levels

Time for intraoperative verification imaging (CBCT and/or Fluoroscopy)

Screw placement time (per screw, from start with awl to screw placed)

The scoliosis specific questionnaire SRS-22r ranging from 1 (worst) to 5 (best)

The scoliosis specific questionnaire EOSQ-24 ranging from 0 (worst) to 100 (best)

The back disabiliy questionnaire (ODI) ranging from 0 (best) to 100 (worst)

The generic quality of life EQ-5D-3L index ranging from -0.59 (worst) to 1.00 (best)

Number of patients that have had complications

Number of patients that have undergone revision surgeries

Augmented reality surgical navigation (ARSN). Pedicle screw placement using the Philips
ClarifEye system combined with Philips Allura for imaging.

Free hand (FH) surgical technique. Pedicle screw placement using conventional free hand
technique.

Infrared surgical navigation (IRSN). Pedicle screw placement using Brainlab Curve 1.2
combined with Medtronic o-arm for imaging.

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

About this trial

Study ID

Status

Type

Phase

Placebo

Accepting

Not accepting

Trial Timing

What is this trial about?

What are the participation requirements?

Locations

Location

Status