P39. Radiographic Outcome of Pedicle Screw Fixation for Upper Thoracic Spine (T1-T5) Fractures

Abstract Objective: To compare the biomechanics of costotransverse process screw fixation with those of pedicle screw fixation in a cadaveric model of the upper thoracic spine. Methods: Ten human thoracic spines were instrumented across the T3–T4 segment with costotransverse and pedicle screws. Nonconstraining pure moments (maximum, 6.0 Nm) were applied to induce flexion, extension, lateral bending, and axial rotation. The range of motion, lax zone, and stiff zone were determined in each specimen in the normal state, after 3-column destabilization, and after instrumentation. After flexibility testing was completed, axial screw pull-out strength was assessed. Results: In all directions of loading, both fixation techniques significantly decreased lax zone and range of motion at T3–T4 compared with the destabilized state (P < .001). During all loading modes except lateral bending, pedicle screw fixation allowed significantly less range of motion than costotransverse screw fixation. Pedicle screws provided 62% greater resistance to axial pull-out than costotransverse screws. Conclusion: The costotransverse screw technique seems to provide only moderately stiff fixation of the destabilized thoracic spine. Pedicle screw fixation seems to have more favorable biomechanical properties. These data suggest that the costotransverse process construct is better used as a salvage procedure rather than as a primary fixation strategy.

Download Full-text

Thoracic spondylotic myelopathy presumably caused by diffuse idiopathic skeletal hyperostosis in a patient who underwent decompression and percutaneous pedicle screw fixation

SAGE Open Medical Case Reports ◽

10.1177/2050313x20987796 ◽

2021 ◽

Vol 9 ◽

pp. 2050313X2098779

Author(s):

Shota Miyoshi ◽

Tadao Morino ◽

Haruhiko Takeda ◽

Hiroshi Nakata ◽

Masayuki Hino ◽

...

Keyword(s):

Pedicle Screw ◽

Screw Fixation ◽

Diffuse Idiopathic Skeletal Hyperostosis ◽

Pedicle Screw Fixation ◽

Vertebral Bone ◽

Bone Bridge ◽

Percutaneous Pedicle Screw ◽

Bilateral Lower Limb ◽

Upper Thoracic ◽

Percutaneous Pedicle Screw Fixation

A 74-year-old man developed bilateral lower limb spastic paresis. He was diagnosed with thoracic spondylotic myelopathy presumably caused by mechanical stress that was generated in the intervertebral space (T1-T2) between a vertebral bone bridge (C5-T1) due to diffuse idiopathic skeletal hyperostosis after anterior fixation of the lower cervical spine and a vertebral bone bridge (T2-T7) due to diffuse idiopathic skeletal hyperostosis in the upper thoracic spine. Treatment included posterior decompression (T1-T2 laminectomy) and percutaneous pedicle screw fixation at the C7-T4 level. Six months after surgery, the patient could walk with a cane, and the vertebral bodies T1-T2 were bridged without bone grafting. For thoracic spondylotic myelopathy associated with diffuse idiopathic skeletal hyperostosis, decompression and percutaneous pedicle screw fixation are effective therapies.

Download Full-text

Novel free-hand T1 pedicle screw method: Review of 44 consecutive cases

Journal of Neurosciences in Rural Practice ◽

10.4103/0976-3147.139974 ◽

2014 ◽

Vol 05 (04) ◽

pp. 349-354 ◽

Cited By ~ 2

Author(s):

Mark A. Rivkin ◽

Jessica F. Okun ◽

Steven S. Yocom

Keyword(s):

Pedicle Screw ◽

Thoracic Spine ◽

Pedicle Screws ◽

High Rate ◽

Imaging Modalities ◽

Neurological Deficits ◽

Upper Thoracic Spine ◽

Starting Point ◽

Grade 3 ◽

Upper Thoracic

ABSTRACT Summary of Background Data: Multilevel posterior cervical instrumented fusions are becoming more prevalent in current practice. Biomechanical characteristics of the cervicothoracic junction may necessitate extending the construct to upper thoracic segments. However, fixation in upper thoracic spine can be technically demanding owing to transitional anatomy while suboptimal placement facilitates vascular and neurologic complications. Thoracic instrumentation methods include free-hand, fluoroscopic guidance, and CT-based image guidance. However, fluoroscopy of upper thoracic spine is challenging secondary to vertebral geometry and patient positioning, while image-guided systems present substantial financial commitment and are not readily available at most centers. Additionally, imaging modalities increase radiation exposure to the patient and surgeon while potentially lengthening surgical time. Materials and Methods: Retrospective review of 44 consecutive patients undergoing a cervicothoracic fusion by a single surgeon using the novel free-hand T1 pedicle screw technique between June 2009 and November 2012. A starting point medial and cephalad to classic entry as well as new trajectory were utilized. No imaging modalities were employed during screw insertion. Postoperative CT scans were obtained on day 1. Screw accuracy was independently evaluated according to the Heary classification. Results: In total, 87 pedicle screws placed were at T1. Grade 1 placement occurred in 72 (82.8%) screws, Grade 2 in 4 (4.6%) screws and Grade 3 in 9 (10.3%) screws. All Grade 2 and 3 breaches were <2 mm except one Grade 3 screw breaching 2-4 mm laterally. Only two screws (2.3%) were noted to be Grade 4, both breaching medially by less than 2 mm. No new neurological deficits or returns to operating room took place postoperatively. Conclusions: This modification of the traditional starting point and trajectory at T1 is safe and effective. It attenuates additional bone removal or imaging modalities while maintaining a high rate of successful screw placement compared to historical controls.

Download Full-text