Use of a Novel Computerized Drill for Pedicle Screw Insertion in the Thoracic and Lumbar Spine: A Cadaveric Study

Background A variety of techniques have been utilized to improve the accuracy of pedicle screw instrumentation. Recently, a novel handheld computerized drill system, IntelliSense Drill Technology, has been used in orthopedic trauma to improve drilling accuracy and reduce radiation and iatrogenic injury. The specialized drill technology detects changes in cortical density to prevent inadvertent cortical violation. The aim of this study is to assess the ability of this system to identify pedicle trajectories in the thoracic and lumbar spine compared to a standard freehand technique.

Methods Two spine surgeons, including 1 senior-level and 1 junior-level attending drilled pedicle screw tracts using a freehand technique and computerized drill technology in 4 cadaveric spines from T2 to S1. A total of 134 pedicle screws were placed, including 70 by the senior surgeon and 64 by the junior surgeon. Cortical violations were assessed using computed tomography after instrumenting each pedicle tract, and procedure time for insertion of pedicle screws was recorded.

Results A total of 15 (22.4%) and 12 (18.2%) pedicle violations were noted using the freehand and computerized drill technique, respectively (P = .767). Perforations using the computerized drill decreased from 31.1% in the first attempt to 5.9% in the second attempt (P = .027). Mean drill time per pedicle using the freehand and computerized drill techniques were comparable (12.2 ± 8.4 versus 12.1 ± 13.2, P = .871), and both surgeons had an improvement in procedure time using the computerized drill (surgeon 1: 12.3 ± 13.7–5.7 ± 3.8 [SD], P = .059; surgeon 2: 20.3 ± 20.0–10.4 ± 5.6 [SD], P = .063).

Conclusions We demonstrate the use of a novel drill technology for placement of pedicle screws in the thoracic and lumbar spine. After an initial learning curve, this technology is comparable to use of a freehand technique by both a senior-level and a junior-level attending surgeon in a cadaveric model. Further investigation is needed to identify the clinical role of this technology in spine surgery.