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  • Author or Editor: Stefan A. Rath x
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Thomas Kretschmer, Gregor Antoniadis, Veit Braun, Stefan A. Rath and Hans-Peter Richter

Object. The purpose of this study was to discover the number and types of iatrogenic nerve injuries that were surgically treated during a 9-year period at a relatively busy nerve center. The specific nerves involved, their sites of injury, and the mechanisms of injury were also documented.

Methods. The authors retrospectively evaluated the surgically treated iatrogenic lesions by reviewing case histories, operative reports, and follow-up notes in 722 cases of trauma. These cases were treated between January 1990 and December 1998 because of pain, dysesthesias, and sensory and/or motor deficits.

Iatrogenic injury was a much larger category of trauma than predicted. One hundred twenty-six (17.4%) of the 722 surgically treated cases were iatrogenic in origin. Most of these injuries occurred during a previous operation. To a major extent, nerves of the extremities were affected, and a relatively large number of injuries occurred in the neck and groin. Incidence was highest in the spinal accessory nerve (14 cases), the common peroneal nerve (11 cases), the superficial radial nerve (10 cases), the genitofemoral nerve branches (10 cases), and the median nerve (nine cases). At least two thirds of the patients did not undergo surgery for the iatrogenic injury within an optimal time interval due to delayed referral. Follow-up data were available in 97 of the 126 patients. Surgical outcomes demonstrated improvement in 70% of patients. Operative results were especially favorable in patients suffering from iatrogenic injuries to the accessory and superficial sensory radial nerves.

Conclusions. Iatrogenic injuries should be corrected in a timely fashion just like any other traumatic injury to nerve.

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Stefan A. Rath, Slawomir Moszko, Petra M. Schäffner, Giuseppe Cantone, Veit Braun, Hans-Peter Richter and Gregor Antoniadis

Object

Although transpedicular fixation is a biomechanically superior technique, it is not routinely used in the cervical spine. The risk of neurovascular injury in this region is considered high because the diameter of cervical pedicles is very small and their angle of insertion into the vertebral body varies. This study was conducted to analyze the clinical accuracy of stereotactically guided transpedicular screw insertion into the cervical spine.

Methods

Twenty-seven patients underwent posterior stabilization of the cervical spine for degenerative instability resulting from myelopathy, fracture/dislocation, tumor, rheumatoid arthritis, and pyogenic spondylitis. Fixation included 1–6 motion segments (mean 2.2 segments). Transpedicular screws (3.5-mm diameter) were placed using 1 of 2 computer-assisted guidance systems and lateral fluoroscopic control. The intraoperative mean deviation of frameless stereotaxy was < 1.9 mm for all procedures.

Results

No neurovascular complications resulted from screw insertion. Postoperative computed tomography (CT) scans revealed satisfactory positioning in 104 (90%) of 116 cervical pedicles and in all 12 thoracic pedicles. A noncritical lateral or inferior cortical breach was seen with 7 screws (6%). Critical malplacement (4%) was always lateral: 5 screws encroached into the vertebral artery foramen by 40–60% of its diameter; Doppler sonographic controls revealed no vascular compromise. Screw malplacement was mostly due to a small pedicle diameter that required a steep trajectory angle, which could not be achieved because of anatomical limitation in the exposure of the surgical field.

Conclusions

Despite the use of frameless stereotaxy, there remains some risk of critical transpedicular screw malpositioning in the subaxial cervical spine. Results may be improved by the use of intraoperative CT scanning and navigated percutaneous screw insertion, which allow optimization of the transpedicular trajectory.