Pedicle screw instrumentation for thoracolumbar burst fractures and fracture-dislocations.

Thirty-eight patients with unstable thoracolumbar and lumbar (T12-L5) spine fractures were treated with Cotrel-Dubousset pedicle screw instrumentation. They were followed for an average of 22.73 months (range 12-39). Measurements of canal compromise, wedge index, and kyphosis correction at follow-up examination were made. Thirty-three (86%) patients responded to a questionnaire concerning overall satisfaction, use of pain medication and return to work. There was an overall correction of kyphosis at follow-up of only one degree after a loss of six degrees from operative correction. There were nine cases of bent or broken screws that occurred at the thoracolumbar junction. Only one patient with instrumentation required continued pain medication and most had returned to work. Thirty-two of thirty-three patients were satisfied with the overall surgical result and twenty-eight of thirty-three patients had returned to work.

Anterolateral dynamized instrumentation and fusion for unstable thoracolumbar and lumbar burst fractures.

STUDY DESIGN: A retrospective chart review of 36 patients treated with dynamized anterolateral instrumentation and fusion after decompression for thoracolumbar and lumbar burst fractures is presented. OBJECTIVES: To evaluate a device that allows continual bone graft vertebral endplate compression and determine its potential for healing in patients with thoracolumbar and lumbar burst fractures. SUMMARY OF BACKGROUND DATA: Anterior spinal surgery has led to implant adaptations. Such implants have undergone an evolution in hopes of improving the rate of healing and avoiding neurovascular catastrophes. METHODS: Thirty-six patients underwent anterior decompression dynamized instrumentation and fusion for thoracolumbar and lumbar burst fractures. This involved a dual-rod, quadrilateral, cross-linked frame that allows for continual compression but deters rotation and shear stresses. RESULTS: All patients healed solidly without instrumentation failure. An average recovery of 1.3 Frankel grades was recorded. Subsidence of bone graft vertebral endplate was less than in those placed in a trough. CONCLUSIONS: Dynamized load-sharing anterolateral Cotrel-Dubousset instrumentation led to solid bone graft healing without implant failure by allowing continual compression while deterring shear and rotational stresses.

SRS travelling fellowship.

A 3-week tour of the Far East was coordinated by Dr. Ronald DeWald, senior travelling fellow appointed by the Scoliosis Research Society. Three junior fellows appointed by the Education Committee of the Scoliosis Research Society accompanied him. The purpose of this fellowship was to develop a comaraderie and exchange ideas, thoughts, and experiences in the field of spinal deformity.

In vitro simulation. Early results of stereotaxy for pedicle screw placement.

STUDY DESIGN: Frameless stereotaxy with doppler ultrasound and three dimensional computer model registration is assessed in vitro for pedicle screw placement. OBJECTIVE: To identify feasibility of pedicle screw navigation and placement using this technology. SUMMARY OF BACKGROUND DATA: Inaccurate pedicle screw placement can lead to neurovascular injury or suboptimal fixation. Present techniques in pedicle screw placement involve only confirmation of hole orientation. METHOD: Forty-four pedicle screws were placed in lumbosacral models and cadaver specimens. Accuracy was assessed with a computed tomography scan and vertebral cross sectioning. RESULTS: All screws were intrapedicular. Accuracy of anterior cortical fixation was 1.5 mm, with a range of 2.5 mm. CONCLUSION: In vitro frameless stereotaxy is accurate for pedicle screw placement. This technology adds a component of navigation to pedicle screw placement.

Complex fracture of the radial neck in a child: an unusual case.

A rare elbow fracture pattern involving the radial neck, olecranon, and medial epicondyle is described in a pediatric patient. Medial and lateral fixation was necessary to control the three planes of instability. Commonly, radial neck fractures with an associated elbow injury (olecranon or medial epicondyle) are stable with lateral fixation alone.

Anterior dural laceration caused by thoracolumbar and lumbar burst fractures.

A retrospective review of the records of 60 patients with thoracolumbar and lumbar burst fractures was undertaken to document the incidence and evaluate the sequelae of dural injuries found during anterior procedures. In the entire series, six (10%) patients each had a preexisting vertically oriented dural tear. All patients with anterior dural lacerations were male and had associated neurologic deficits. In all six patients, preoperative computed tomography showed an asymmetrically retropulsed bone fragment. Dural tears were repaired primarily. A postoperative cerebrospinal fluid leak developed into the chest cavity of one patient, who was treated successfully with subarachnoid drainage. In patients with anterior dural laceration, primary repair is warranted and can be performed more easily after intraoperative correction of kyphosis. Subarachnoid drainage may be effective in cases of continued postoperative anterior cerebrospinal fluid leakage before repeated operation is considered.

In vivo pedicle screw placement: image-guided virtual vision.

Near-real-time frameless stereotaxy registering intraoperative anatomy to a preoperative three-dimensional computer model has been developed for use with in vivo pedicle screw placement. Eight patients underwent thoracolumbar and lumbar spine stabilization surgery using this new technology, and 32 pedicle screws were placed. Three additional patients had 12 pedicle screws removed during revision surgery, and they allowed the authors to estimate the accuracy of this navigational system. Accuracy was determined by comparing pedicle screw position on postoperative computed tomographs for the first eight patients and on preoperative computed tomographs for the latter three patients, with the intraoperative computer trajectory data gathered during operation. In the group of eight patients, all screws were intrapedicular. In evaluating all 11 patients, the overall accuracy was +/- 2 mm, but the greatest error of 5.4 mm was noted in the sagittal plane measurement. During the development phase of this technology, time constraints prolong surgery, but this may be addressed once the tool's accuracy has been confirmed and intraoperative radiographic confirmation becomes unnecessary. In vivo real-time frameless stereotaxy for pedicle screw placement offers promise for the future. Refinements are needed to improve accuracy and address time constraints.