Improved accuracy of computer-assisted cervical pedicle screw insertion

Abstract

<jats:p content-type="fine-print"><jats:italic>Object.</jats:italic> The authors introduce a unique computer-assisted cervical pedicle screw (CPS) insertion technique used in conjunction with specially modified original pedicle screw insertion instruments. The accuracy of screw placement as well as surgery-related outcome and complication rates were compared between two groups of patients: those in whom a computer-assisted and those in whom a conventional manual insertion technique was used.</jats:p> <jats:p content-type="fine-print"><jats:italic>Methods.</jats:italic> The screw insertion guiding system consisted of a modified awl, probe, tap and a screwdriver specially designed for a computer-assisted CPS insertion. Using this system, real-time instrument/screw tip information was three dimensionally identified in each step of screw insertion. Seventeen patients underwent CPS fixation in which a computer-assisted surgical navigation system was used. The cervical disorders consisted of spondylotic myelopathy with segmental instability or kyphosis, metastatic spinal tumor, rheumatoid spine, and postlaminectomy kyphosis. The rate of pedicle wall perforation was significantly lower in the computer-assisted group than that in the other group (1.2 and 6.7%, respectively; p &lt; 0.05). The screw trajectory in the horizontal plane was significantly closer to the anatomical pedicle axis in the computer-assisted group compared with the manual insertion group (p &lt; 0.05). This factor significantly reduced the incidence of screw perforation laterally. Complications such as neural damage or vascular injury were not demonstrated in the computer-assisted group (compared with 2% in the manual insertion treatment group). The overall surgery-related outcome was satisfactory.</jats:p> <jats:p content-type="fine-print"><jats:italic>Conclusions.</jats:italic> In contrast to the previously reported computer-assisted technique, our CPS insertion technique provides real-time three-dimensional instrument/screw tip information. This serves as a powerful tool for safe and accurate pedicle screw placement in the cervical spine.</jats:p>

Functional outcome of computer-assisted spinal pedicle screw placement: a systematic review and meta-analysis of 23 studies including 5,992 pedicle screws

“…At review, 48 papers were excluded as they did not meet the inclusion criteria (Table 1). Thus, 23 publications [5,6,8,9,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] were analysed in this paper (Table 2; 2 randomised controlled trials, 12 case-control studies and 9 case series). Three studies were in German language and remaining 20 studies were in English.…”

“…Six studies [12,13,19,24,26,30] reported follow-up period ranging from 15 to 34 months, while one study followed the patients to clinical and radiological bony fusion [16], but none reported on rate of fusion achieved.…”

The ipsilateral lamina–pedicle angle: can it be used to guide pedicle screw placement in the sub-axial cervical spine?

“…A decrease in perforation rates from 66.5 to 10.6% was shown. Three other studies have also found a benefit in using computer guidance during such surgery [13,19,31]; however, no matter which technique is employed, there is still a need for the surgeon to understand the anatomical landmarks, We, along with the paper by Hacker et al [10], advocate the use of the posterior elements as a reference for the trajectory of pedicle screw insertion. However, there is a significant limitation to both our techniques, which they also mentioned.…”

“…Developments in computer-assisted surgery have subsequently been analysed and have shown a higher success rate than other image-guided techniques [19,24]. However, as Kamimura et al [13] quite rightly pointed out, the surgeon still needs to know the pedicle morphology to ensure that the computer guides the screws correctly.…”

Percutaneous instrumentation of the cervical and cervico-thoracic spine using pedicle screws: preliminary clinical results and analysis of accuracy

“…However, this technique has a potential risk of nerve root, spinal cord and vertebral artery injury due to a small corridor of safe screw placement [31,39,41], recent clinical studies demonstrate that relevant complications do not occur frequently [2,9,11,15,18,24,26,29,47,48]. The axis of the cervical pedicles to the sagittal midline plane vary between 25 and 60°and makes a wide exposure of the spine necessary [14].…”