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

2014 ◽  
Vol 05 (04) ◽  
pp. 349-354 ◽  
Author(s):  
Mark A. Rivkin ◽  
Jessica F. Okun ◽  
Steven S. Yocom

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.

2019 ◽  
Vol 16 (2) ◽  
pp. 35-41 ◽  
Author(s):  
R. A. Kovalenko ◽  
V. V. Rudenko ◽  
V. A. Kashin ◽  
V. Yu. Cherebillo ◽  
D. A. Ptashnikov

Objective. To analyze the safety and accuracy of pedicle screw placement in the subaxial cervical and upper thoracic spine using patient-specific 3D navigation templates.Material and Methods. The study included 16 patients who underwent transpedicular implantation of screws in the subaxial cervical and upper thoracic vertebrae using patient-specific 3D navigation templates. A total of 88 screws were installed. All patients underwent preoperative CT angiography to assess visualization of the vertebral artery. Customized vertebral models and navigation templates were created using 3D printing technology. Models and templates were sterilized and used during surgery. The results of screw implantation, as well as the safety and accuracy of the placement, were assessed by postoperative CT.Results. The average deviation from the planned trajectory was 1.8 ± 0.9 mm. Deviation was estimated as class 1 (<2 mm) for 57 (64.77 %) screws, class 2 (2–4 mm) for 29 (32.95 %), and class 3 for two (2.27 %). The safety of screw implantation of grade 0 (the screw is completely inside the bone structure) was in 79 (89.77 %) cases, of grade 1 (<50 % of the screw diameter perforates the bone) – in 5 (5.68 %), and of grade 3 – in 2 (2.27 %).Conclusion. Using 3D navigation templates is an affordable and safe method of installing pedicle screws in the cervical and upper thoracic spine. The method can be used as an alternative to intraoperative CT navigation.


2010 ◽  
Vol 66 (suppl_1) ◽  
pp. ons-178-ons-182
Author(s):  
Andrew S. Little ◽  
Leonardo B.C. Brasiliense ◽  
Bruno C.R. Lazaro ◽  
Phillip M. Reyes ◽  
Curtis A. Dickman ◽  
...  

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 &lt; .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.


2006 ◽  
Vol 5 (6) ◽  
pp. 527-533 ◽  
Author(s):  
Ryan M. Kretzer ◽  
Daniel M. Sciubba ◽  
Carlos A. Bagley ◽  
Jean-Paul Wolinsky ◽  
Ziya L. Gokaslan ◽  
...  

Object The use of pedicle screws (PSs) for instrument-assisted fusion in the cervical and thoracic spine has increased in recent years, allowing smaller constructs with improved biomechanical stability and repositioning possibilities. In the smaller pedicles of the upper thoracic spine, the placement of PSs can be challenging and may increase the risk of damage to neural structures. As an alternative to PSs, translaminar screws can provide spinal stability, and they may be used when pedicular anatomy precludes successful placement of PSs. The authors describe the technique of translaminar screw placement in the T-1 and T-2 vertebrae. Methods Seven patients underwent cervicothoracic fusion to treat trauma, neoplasm, or degenerative disease. Nineteen translaminar screws were placed, 13 at T-1 and six at T-2. A single asymptomatic T-2 screw violated the ventral laminar cortex and was removed. The mean clinical and radiographic follow up exceeded 14 months, at which time there were no cases of screw pull-out, screw fracture, or progressive kyphotic deformity. Conclusions Rigid fixation with translaminar screws offers an attractive alternative to PS fixation, allowing the creation of sound spinal constructs and minimizing potential neurological morbidity. Their use requires intact posterior elements, and care should be taken to avoid violation of the ventral laminar wall.


2013 ◽  
Vol 19 (6) ◽  
pp. 701-707 ◽  
Author(s):  
Ankit I. Mehta ◽  
Owoicho Adogwa ◽  
Isaac O. Karikari ◽  
Paul Thompson ◽  
Terence Verla ◽  
...  

Object Intradural extramedullary (IDEM) neoplasms are uncommon lesions that can pose a challenge for resection. Numerous factors affect the resectability and ultimately the outcome of these lesions. The authors report their 10-year institutional experience with the resection of IDEM neoplasms, focusing on the effect of location on surgical outcomes. Methods The authors performed a retrospective review of 96 consecutive patients who presented with a cervical and/or thoracic IDEM tumor that was resected between February 2000 and July 2009. All patients underwent MRI, and the axial location of the tumor was categorized as anterior, posterior, or lateral. Postoperative complications were assessed, as was neurological status at the patient's last follow-up clinic visit. Major complications assessed included CSF leakage requiring lumbar drainage, reexploration for epidural hematoma, and major postoperative neurological deficits. Results The mean ± SD age at presentation was 51.16 ± 17.87 years. Major surgical approach–related complications occurred in 15% of patients. Major non–approach related surgical complications occurred in 7.1% of patients, while minor complications occurred in 14.2% of patients. Postoperative neurological deficits occurred most commonly in the thoracic spine between T-1 and T-8. Based on axial spinal cord location, the surgery-related complications rates for all anterior tumors (n = 12) was 41.6%, whereas that for all lateral tumors (n = 69) was 4.4% and that for all posteriorly located tumors (n = 17) was 0%. Conclusions Spinal IDEM tumors that are anteriorly located in the upper thoracic spine were found to have the highest rate of surgery-related complications and postoperative neurological deficits. This finding may be associated with the unforgiving anatomy of the upper thoracic spine in which there is a higher cord-to-canal ratio and a tenuous vascular supply.


2010 ◽  
Vol 68 (3) ◽  
pp. 390-395 ◽  
Author(s):  
Bruno Perocco Braga ◽  
Josaphat Vilela de Morais ◽  
Marcelo Duarte Vilela

OBJECTIVE: To evaluate the feasibility, safety and accuracy of pedicle screw placement in the upper thoracic spine using the free-hand technique with the aid of fluoroscopy; to analyze the methods used to verify correct screw positioning intra and postoperatively. METHOD: All patients with instability of the cervicothoracic or upper thoracic spine and at least one screw placed in the segment T1-T6 as part of a posterior construct entered the study. Only C-arm intraoperative fluoroscopy was used to guide screw placement. RESULTS: We obtained excellent positioning in 98.07% of the screws. CT scans precisely demonstrated pedicle wall and anterolateral body violations. There was no hardware failure, no neurological or vascular injury and no loss of alignment during the follow-up period. CONCLUSION: Pedicle screws can be safely placed in the upper thoracic spine when strict technical principles are followed. Only a CT scan can precisely demonstrate vertebral body and medial pedicle cortical violations.


2018 ◽  
Vol 2 (1) ◽  
pp. 01-04
Author(s):  
Anbis El Hakim

Objective: Evolving pressure on surgical education necessitates safe and efficient learning of techniques. We evaluated the effect of training year using anatomic, percutaneous fluoroscopy guided and computer navigated techniques on the accuracy of pedicle screw placement to attempt to determine if different modalities may be better suited for different levels of training. Methods: All instrumented thoracic and lumbar cases performed at Detroit Medical Center by the Neurosurgery Service between August 2012 and June 2013 were included.Cases had hardware verified by post-operative CT. Hardware placement was graded according to Mirza SK et al., grade 0 (within pedicle), grade 1 (< 2 mm breach), grade 2 (> 2 mm breach) , and grade 3 (extrapedicular). Pedicle screws were reviewed independently by a resident and attending surgeon. Rates of pedicle breach, EBL, length of case, pedicle size and pedicle starting point were all reviewed. Pedicles were analyzed on PACS system in axial views, using sagittal views to identify the correct level. Results: A total of 306 pedicle screws were evaluated in 36 patients. The overall rate of accurate pedicle screw placement among residents defined as Grade 0 or 1 placement was 86.8%.Fluoroscopically placed screws had significantly less breaches than anatomic screws 11% vs 20% (p = 0.03). Fluoroscopic cases had significantly less medial breeches (20%) than anatomic (50%) (p < 0.05) and computer assisted cases (73%) (p < 0.05). EBL values for fluoroscopic, anatomic and Body Tom cases were 425 cc, 720 cc, and 816 cc respectively. Resident level was found to be inversely proportional to breech rate (R squared 0.45). We did not see any clear difference in breach rate for resident level in different modalities. Conclusion: Supervised neurosurgical residents can place pedicle screws within published rates of acceptable breach. Interestingly our study revealed an inverse relationship between resident experience and pedicle screw accuracy. Fluoroscopic placement of pedicle screws compared to computer assisted and anatomic techniques results in lower medial breach rate and may be better suited for junior level residents.


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