Cortical-bone-trajectory-based dynamic stabilization

2021 ◽  
Author(s):  
Yi-Hsuan Kuo ◽  
Chao-Hung Kuo ◽  
Hsuan-Kan Chang ◽  
Chin-Chu Ko ◽  
Tsung-Hsi Tu ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Dynamic Stabilization ◽  
Cortical Bone Trajectory

scholarly journals Minimally invasive dynamic screw stabilization using cortical bone trajectory

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Chih-Chang Chang ◽  
Chao-Hung Kuo ◽  
Hsuan-Kan Chang ◽  
Tsung-Hsi Tu ◽  
Li-Yu Fay ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Cortical Bone ◽  
Pedicle Screw ◽  
Case Series ◽  
Dynamic Stabilization ◽  
Low Grade ◽  
Cortical Bone Trajectory ◽  
Screw Insertion ◽  
Soft Tissue Dissection ◽  
Spinal Navigation

Abstract Background The conventional pedicle-screw-based dynamic stabilization process involves dissection of the Wiltse plane to cannulate the pedicles, which cannot be undertaken with minimal surgical invasion. Despite some reports having demonstrated satisfactory outcomes of dynamic stabilization in the management of low-grade spondylolisthesis, the extensive soft tissue dissection involved during pedicle screw insertion substantially compromises the designed rationale of motion (muscular) preservation. The authors report on a novel method for minimally invasive insertion of dynamic screws and a mini case series. Methods The authors describe innovations for inserting dynamic screws via the cortical bone trajectory (CBT) under spinal navigation. All the detailed surgical procedures and clinical data are demonstrated. Results A total of four (2 females) patients (mean age 64.75 years) with spinal stenosis at L4–5 were included. By a combination of microscopic decompression and image-guided CBT screw insertion, laminectomy and dynamic screw stabilization were achieved via one small skin incision (less than 3 cm). These patients’ back and leg pain improved significantly after the surgery. Conclusion This innovative dynamic screw stabilization via the CBT involved no discectomy (or removal of sequestrated fragment only), no interbody fusion, and little muscle dissection (not even of the Wiltse plane). As a minimally invasive surgery, CBT appeared to be a viable alternative to the conventional pedicle-screw-based dynamic stabilization approach.

Depth of vertebral screw insertion using a cortical bone trajectory technique in lumbar spinal fusion: radiological significance of a long cortical bone trajectory

2021 ◽  
pp. 1-6
Author(s):  
Keitaro Matsukawa ◽  
Yoshihide Yanai ◽  
Kanehiro Fujiyoshi ◽  
Takashi Kato ◽  
Yoshiyuki Yato
Keyword(s):  
Cortical Bone ◽  
Vertebral Body ◽  
Screw Loosening ◽  
Lumbar Spinal Fusion ◽  
Insertion Depth ◽  
Cortical Bone Trajectory ◽  
Screw Insertion ◽  
Bone Fusion ◽  
Screw Length ◽  
Lumbar Spinal

OBJECTIVE Contrary to original cortical bone trajectory (CBT), “long CBT” directed more anteriorly in the vertebral body has recently been recommended because of improved screw fixation and load sharing within the vertebra. However, to the authors’ knowledge there has been no report on the clinical significance of the screw length and screw insertion depth used with the long CBT technique. The aim of the present study was to investigate the influence of the screw insertion depth in the vertebra on lumbar spinal fusion using the CBT technique. METHODS A total of 101 consecutive patients with L4 degenerative spondylolisthesis who underwent single-level posterior lumbar interbody fusion at L4–5 using the CBT technique were included (mean follow-up 32.9 months). Screw loosening and bone fusion were radiologically assessed to clarify the factors contributing to these outcomes. Investigated factors were as follows: 1) age, 2) sex, 3) body mass index, 4) bone mineral density, 5) intervertebral mobility, 6) screw diameter, 7) screw length, 8) depth of the screw in the vertebral body (%depth), 9) facetectomy, 10) crosslink connector, and 11) cage material. RESULTS The incidence of screw loosening was 3.1% and bone fusion was achieved in 91.7% of patients. There was no significant factor affecting screw loosening. The %depth in the group with bone fusion [fusion (+)] was significantly higher than that in the group without bone fusion [fusion (−)] (50.3% ± 8.2% vs 37.0% ± 9.5%, respectively; p = 0.001), and multivariate logistic regression analysis revealed that %depth was a significant independent predictor of bone fusion. Receiver operating characteristic curve analysis identified %depth > 39.2% as a predictor of bone fusion (sensitivity 90.9%, specificity 75.0%). CONCLUSIONS This study is, to the authors’ knowledge, the first to investigate the significance of the screw insertion depth using the CBT technique. The cutoff value of the screw insertion depth in the vertebral body for achieving bone fusion was 39.2%.

128 Application of Cortical Bone Trajectory Instrumentation for Juvenile and Adolescent Idiopathic Scoliosis

Neurosurgery ◽  
2016 ◽  
Vol 63 ◽  
pp. 152-153 ◽  
Author(s):  
Vishal J. Patel ◽  
Sohum K. Desai ◽  
Ken Maynard ◽  
Randall Zain Allison ◽  
Thomas Frank ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cortical Bone ◽  
Cortical Bone Trajectory

Comparison of Three Different Screw Trajectories in Osteoporotic Vertebrae: A Biomechanical Investigation

2020 ◽  
Author(s):  
Jan-Sven Jarvers ◽  
Stefan Schleifenbaum ◽  
Christian Pfeifle ◽  
Christoph Oefner ◽  
Melanie Edel ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Fatigue Behavior ◽  
Fixation Strength ◽  
Patient Specific ◽  
Promising Alternative ◽  
Cortical Bone Trajectory ◽  
Pull Out ◽  
Group A ◽  
The Mean ◽  
Group B

Abstract Background: Pedicle screw insertion in osteoporotic patients is challenging. Achieving more screw-cortical bone purchase and invasiveness minimization, the cortical bone trajectory and the midline cortical techniques represent alternatives to traditional pedicle screws. This study compares the fatigue behavior and fixation strength of the cement-augmented traditional trajectory (TT), the cortical bone trajectory (CBT) and the midline cortical (MC). Methods: Ten human cadaveric spine specimens (L1 - L5) were examined. The average age was 86.3 ± 7.2 years. CT scans were provided for preoperative planning. CBT and MC were implanted by using the patient-specific 3D-printed placement guide (MySpine®, Medacta International), TT were implanted freehand. All 10 cadaveric specimens were randomized to group A (CBT vs. MC) or group B (MC vs. TT). Each screw was loaded for 10,000 cycles. The failure criterion was doubling of the initial screw displacement resulting from the compressive force (60 N) at the first cycle, the stop criterion as a doubling of the initial screw displacement. After dynamic testing, screws were pulled out axially at 5 mm/min to determine their remaining fixation strength. Results: The mean pull-out forces did not differ significantly. Concerning the fatigue performance, only one out of ten MC of group A failed prematurely due to loosening after 1,500 cycles (L3). Five CBT already loosened during the first 500 cycles. The mean displacement was always lower in the MC. In group B, all TT showed no signs of failure or loosening. Three MC failed already after 26 cycles, 1,510 cycles, and 2,144 cycles, respectively. The TT showed always a lower mean displacement. In the subsequent pull-out tests, the remaining mean fixation strength of the MC (449.6 ± 298.9 N) was slightly higher compared to the mean pull-out force of the CBT (401.2 ± 261.4 N). However, MC (714.5 ± 488.0 N) were inferior to TT (990.2 ± 451.9 N).Conclusion: The current study demonstrated that cement-augmented TT have best fatigue and pull-out characteristics in osteoporotic lumbar vertebrae, followed by the MC and CBT. MC represent a promising alternative in osteoporotic bone if cement augmentation should be avoided. Using the patient-specific guide contributes to improve screws’ biomechanical properties.

scholarly journals Comparison of facet joint violation in lumbar posterior spinal instrumentation using different techniques including cortical bone trajectory

2020 ◽  
Vol 27 (1) ◽  
pp. 57-62
Author(s):  
CY To ◽  
P Cheung ◽  
W Ng ◽  
WY Mok
Keyword(s):  
Cortical Bone ◽  
Pedicle Screw ◽  
Facet Joint ◽  
Spinal Instrumentation ◽  
Entry Site ◽  
Cortical Bone Trajectory ◽  
Percutaneous Pedicle Screw ◽  
Iatrogenic Damage ◽  
Percutaneous Screws ◽  
Facet Joint Violation

Study background: A retrospective study to compare the rate of facet joint violation (FJV) in lumbar posterior spinal instrumentation using open pedicle screw, percutaneous pedicle screw, and cortical bone trajectory (CBT) technique. CBT is a new posterior spinal instrumentation technique in which a more caudal entry point can minimize iatrogenic damage to the cranial facet joint. Only one recent study reports incidence of FJV of 11%; however, no previous reports comment on radiological outcomes comparing to traditional open and percutaneous screws. Methods: We reviewed 90 patients who underwent lumbar posterior spinal instrumentation from January 2016 to June 2017. Postoperative computer tomography scans were performed to evaluate FJV. Incidence of FJV was graded by three reviewers according to Seo classification. Results: Totally, 446 screws (open 43.4%, percutaneous 37.8%, CBT 18.9%) were inserted. Among these, 6.3% (28/446) had screw head or rod in contact with facet joint and 0.9% (4/446) had screws directly invaded the facet joint. Overall, FJV was 7.2% (CTB = 3.4%, open = 10.4%, and percutaneous = 4.5%, p = 0.075). Conclusion: CBT technique has potential advantage in reducing FJV. It has a unique entry site at lateral aspect of pars interarticular with a caudomedial to craniolateral pathway. It is a reasonable alternative to open or percutaneous techniques in lumbar posterior spinal instrumentation.

Incidence and Risk Factors of Adjacent Cranial Facet Joint Violation Following Pedicle Screw Insertion Using Cortical Bone Trajectory Technique

Spine ◽  
2016 ◽  
Vol 41 (14) ◽  
pp. E851-E856 ◽  
Author(s):  
Keitaro Matsukawa ◽  
Takashi Kato ◽  
Yoshiyuki Yato ◽  
Hiroshi Sasao ◽  
Hideaki Imabayashi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cortical Bone ◽  
Pedicle Screw ◽  
Facet Joint ◽  
Cortical Bone Trajectory ◽  
Screw Insertion ◽  
Pedicle Screw Insertion ◽  
Facet Joint Violation

scholarly journals Posterior lumbar interbody fusion with cortical bone trajectory screw fixation versus posterior lumbar interbody fusion using traditional pedicle screw fixation for degenerative lumbar spondylolisthesis: a comparative study

2016 ◽  
Vol 25 (5) ◽  
pp. 591-595 ◽  
Author(s):  
Hironobu Sakaura ◽  
Toshitada Miwa ◽  
Tomoya Yamashita ◽  
Yusuke Kuroda ◽  
Tetsuo Ohwada
Keyword(s):  
Cortical Bone ◽  
Pedicle Screw ◽  
Surgical Outcomes ◽  
Recovery Rate ◽  
Interbody Fusion ◽  
Screw Fixation ◽  
Posterior Lumbar Interbody Fusion ◽  
Lumbar Interbody Fusion ◽  
Cortical Bone Trajectory

OBJECTIVE Several biomechanical studies have demonstrated the favorable mechanical properties of the cortical bone trajectory (CBT) screw. However, no reports have examined surgical outcomes of posterior lumbar interbody fusion (PLIF) with CBT screw fixation for degenerative spondylolisthesis (DS) compared with those after PLIF using traditional pedicle screw (PS) fixation. The purposes of this study were thus to elucidate surgical outcomes after PLIF with CBT screw fixation for DS and to compare these results with those after PLIF using traditional PS fixation. METHODS Ninety-five consecutive patients underwent PLIF with CBT screw fixation for DS (CBT group; mean followup 35 months). A historical control group consisted of 82 consecutive patients who underwent PLIF with traditional PS fixation (PS group; mean follow-up 40 months). Clinical status was assessed using the Japanese Orthopaedic Association (JOA) scale score. Fusion status was assessed by dynamic plain radiographs and CT. The need for additional surgery and surgery-related complications was also evaluated. RESULTS The mean JOA score improved significantly from 13.7 points before surgery to 23.3 points at the latest follow-up in the CBT group (mean recovery rate 64.4%), compared with 14.4 points preoperatively to 22.7 points at final follow-up in the PS group (mean recovery rate 55.8%; p < 0.05). Solid spinal fusion was achieved in 84 patients from the CBT group (88.4%) and in 79 patients from the PS group (96.3%, p > 0.05). Symptomatic adjacent-segment disease developed in 3 patients from the CBT group (3.2%) compared with 9 patients from the PS group (11.0%, p < 0.05). CONCLUSIONS PLIF with CBT screw fixation for DS provided comparable improvement of clinical symptoms with PLIF using traditional PS fixation. However, the successful fusion rate tended to be lower in the CBT group than in the PS group, although the difference was not statistically significant between the 2 groups.

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