scholarly journals Incidence of Screw Loosening in Cortical Bone Trajectory Fixation Technique between Single- and Dual-Threaded Screws

Medicines ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 50
Author(s):  
Chao-Hsuan Chen ◽  
Chih-Hsiu Tu ◽  
Der-Cherng Chen ◽  
Hsiang-Ming Huang ◽  
Hao-Yu Chuang ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Screw Fixation ◽  
Incidence Rates ◽  
Fixation Strength ◽  
Screw Loosening ◽  
Fixation Technique ◽  
Level Of Evidence ◽  
Fusion Surgery ◽  
Cortical Bone Trajectory ◽  
Plain Films

Purpose: This study aims to elucidate the radiological outcome after Cortical bone trajectory (CBT) screw fixation and whether dual-threaded (DT) screws should be used in the fusion surgery. Methods: 159 patients with degenerative lumbar disorder who had undergone midline lumbar inter-body fusion surgery by CBT screw-fixation technique (2014 to 2018). Patient subgroups were based on single-threaded (ST) or DT screw, fixation length, as well as whether fixation involved to sacrum level (S1). Serial dynamic plain films were reviewed and an appearance of a halo phenomenon between screw–bone interfaces was identified as a case of screw loosening. Results: 29 patients (39.7%) in ST group and 10 patients (11.6%) in DT group demonstrated a halo phenomenon (p < 0.0001 ****). After subgrouping with fixation length, the incidence rates of a halo phenomenon in each group were 11.1%:3% (ST-1L vs. DT-1L), 37%:13.8% (ST-2L vs. DT-2L), and 84.2%:23.5% (ST-3L vs. DT-3L). Among the 85 patients with a fixation involved in S1, 26 patients (52%) with single-threaded screw (STS group) and 8 patients (22.8%) with dual-threaded screw (DTS group) demonstrated a halo appearance (p = 0.0078 **). After subgrouping the fixation level, the incidence of a halo appearance in each group was 25%:0% (STS-1L vs. DTS-1L), 40.9%:26.3% (STS-2L vs. DTS-2L), and 87.5%: 30% (STS-3L vs. DTS-3L). Conclusion: Both fixation length and whether fixation involved to S1 contribute to the incidence of screw loosening, the data supports clinical evidence that DT screws had greater fixation strength with an increased fixative stability and lower incidence of screw loosening in CBT screw fixation compared with ST screws. Level of evidence: 2.

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%.

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 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.

scholarly journals Novel placement of cortical bone trajectory screws in previously instrumented pedicles for adjacent-segment lumbar disease using CT image-guided navigation

2014 ◽  
Vol 36 (3) ◽  
pp. E9 ◽  
Author(s):  
Analiz Rodriguez ◽  
Matthew T. Neal ◽  
Ann Liu ◽  
Aravind Somasundaram ◽  
Wesley Hsu ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Lumbar Fusion ◽  
Pedicle Screw Fixation ◽  
Adjacent Segment ◽  
Average Hospital ◽  
Cortical Bone Trajectory ◽  
Image Guided

Object Symptomatic adjacent-segment lumbar disease (ASLD) after lumbar fusion often requires subsequent surgical intervention. The authors report utilizing cortical bone trajectory (CBT) pedicle screw fixation with intraoperative CT (O-arm) image-guided navigation to stabilize spinal levels in patients with symptomatic ASLD. This unique technique results in the placement of 2 screws in the same pedicle (1 traditional pedicle trajectory and 1 CBT) and obviates the need to remove preexisting instrumentation. Methods The records of 5 consecutive patients who underwent lumbar spinal fusion with CBT and posterior interbody grafting for ASLD were retrospectively reviewed. All patients underwent screw trajectory planning with the O-arm in conjunction with the StealthStation navigation system. Basic demographics, operative details, and radiographic and clinical outcomes were obtained. Results The average patient age was 69.4 years (range 58–82 years). Four of the 5 surgeries were performed with the Minimal Access Spinal Technologies (MAST) Midline Lumbar Fusion (MIDLF) system. The average operative duration was 218 minutes (range 175–315 minutes). In the entire cohort, 5.5-mm cortical screws were placed in previously instrumented pedicles. The average hospital stay was 2.8 days (range 2–3 days) and there were no surgical complications. All patients had more than 6 months of radiographic and clinical follow-up (range 10–15 months). At last follow-up, all patients reported improved symptoms from their preoperative state. Radiographic follow-up showed Lenke fusion grades of A or B. Conclusions The authors present a novel fusion technique that uses CBT pedicle screw fixation in a previously instrumented pedicle with intraoperative O-arm guided navigation. This method obviates the need for hardware removal. This cohort of patients experienced good clinical results. Computed tomography navigation was critical for accurate CBT screw placement at levels where previous traditional pedicle screws were already placed for symptomatic ASLD.

scholarly journals Comparison of cortical bone trajectory versus pedicle screw techniques in lumbar fusion surgery

Medicine ◽  
2019 ◽  
Vol 98 (33) ◽  
pp. e16751 ◽  
Author(s):  
Jing-Nan Hu ◽  
Xiao-Feng Yang ◽  
Chuan-Ming Li ◽  
Xin-Xin Li ◽  
Yun-Zhi Ding
Keyword(s):  
Cortical Bone ◽  
Pedicle Screw ◽  
Lumbar Fusion ◽  
Fusion Surgery ◽  
Cortical Bone Trajectory ◽  
Lumbar Fusion Surgery
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