scholarly journals Hounsfield units of the vertebral body and pedicle as predictors of pedicle screw loosening after degenerative lumbar spine surgery

2020 ◽  
Vol 49 (2) ◽  
pp. E10
Author(s):  
Fei Xu ◽  
Da Zou ◽  
Weishi Li ◽  
Zhuoran Sun ◽  
Shuai Jiang ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Pedicle Screw ◽  
Vertebral Body ◽  
Lumbar Spine Surgery ◽  
Control Group ◽  
Screw Loosening ◽  
Hounsfield Units ◽  
Lumbar Vertebral Body ◽  
Pedicle Screw Loosening ◽  
Loosening Rate

OBJECTIVEThe authors aimed to compare the efficacy of lumbar vertebral body Hounsfield units (HUs) and pedicle HUs at predicting pedicle screw loosening.METHODSThe authors retrospectively assessed 143 patients with L3–5 instrumentation. The patients were classified into one of two groups based on the status of their L3 screws (a screw loosening group or a control group). The pedicle HUs and vertebral HUs of L3 were measured using preoperative lumbar CT scans, and the pedicle HUs were measured in two ways: by excluding or by including cortical bone.RESULTSThe screw loosening rate was 20.3% (n = 29/143) at the 12-month follow-up. The vertebral body HUs and pedicle HUs in the screw loosening group were lower than those in the control group (vertebral body group: 98.6 HUs vs 121.4 HUs, p < 0.001; pedicle excluding cortical bone: 208.9 HUs vs 290.5 HUs, p = 0.002; pedicle including cortical bone: 249.4 HUs vs 337.5 HUs, p < 0.001). The pedicle HUs tended to have a higher area under the receiver operating characteristic curve value in predicting screw loosening, compared with that of vertebral body HUs, but the difference was not statistically significant (p > 0.05). Among patients with low vertebral body HUs of ≤ 130, the loosening rate was much lower in patients with pedicle HUs of ≤ 340 than in those with pedicle HUs of > 340 (31.0% vs 13.0%, respectively; p < 0.05).CONCLUSIONSVertebral body HUs alone are insufficient to accurately evaluate the risk of pedicle screw loosening. Therefore, it is important to collect both the pedicle HU and vertebral body HU measurements for surgical planning.

scholarly journals Incidence and Predictive Factors of Distal Pedicle Screw Loosening Followed Posterior Corrective Surgery for Degenerative Lumbar Scoliosis

2021 ◽  
Author(s):  
Hui Wang ◽  
Longjie Wang ◽  
Zhuoran Sun ◽  
Shuai Jiang ◽  
Weishi Li
Keyword(s):  
Cobb Angle ◽  
Pedicle Screw ◽  
Predictive Factors ◽  
Posterolateral Fusion ◽  
Control Group ◽  
Study Group ◽  
Screw Loosening ◽  
Angle Correction ◽  
Pedicle Screw Loosening

Abstract BackgroundThe aim of this study was to identify the prevalence of distal pedicle screw loosening (DPSL) following posterior decompression and instrumented fusion for DLS, to search for predictable risk factors for DPSL, and hope to provide references in decision making and surgical planning for spine surgeons. MethodsOne hundred and fifty-three consecutive DLS patients surgically treated between January 2013 and July 2018 were retrospectively reviewed. The diagnostic criteria for DPSL developed by X-ray include the radiolucent area (thicker than 1 mm) around screw and the “double halo” sign defined as the presence of radiolucent area and radiopaque rim at the same X-ray. According to the occurrence of DPSL at two-year follow-up, patients were divided into two groups: study group (screw loosening) and control group (without screw loosening). To investigate predictive factors for distal pedicle screw loosening, three categorized factors were analyzed statistically.ResultsDPSL was detected in 72 of 153 patients (47.1%) at two-year follow up, and were enrolled as study group. Another 81 patients presented no screw loosening at two-year follow up, and were enrolled as control group. Hounsfield unit (HU) value was lower in study group than that in control group. Fusion level was longer in study group than that in control group. Lower instrumented vertebrae on L5 was less in study group than that in control group. Posterolateral fusion was less in study group than that in control group. Preoperative Cobb angle, postoperative Cobb angle, Cobb angle correction, preoperative lumbosacral coronal angle (LSCA), LSCA correction, preoperative thoracolumbar junction (TL), postoperative TL were larger in study group than those in control group. Logistic regression analysis revealed that low Bone mineral density (BMD) (<169 HU), posterolateral fusion, Cobb angle correction (>16 degrees), LSCA correction (>9 degrees) were independently associated with DPSL.ConclusionsThe incidence of DPSL following posterior decompression and instrumented fusion for DLS is 47.1%. Low BMD, large correction of both main curve and fractional curve are predictive factors for DPSL, while posterolateral fusion is a protective factor.

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%.

INVESTIGATION INTO WHETHER OR NOT PMMA BONE CEMENT TRANSPEDICULAR SCREW AUGMENTATION STABILIZES PEDICLE SCREW LOOSENING

2019 ◽  
Vol 19 (02) ◽  
pp. 1940024
Author(s):  
PO-YI LIU ◽  
SHENG-CHIH LIN ◽  
PO-LIANG LAI ◽  
CHUN-LI LIN
Keyword(s):  
Bone Cement ◽  
Pedicle Screw ◽  
Fatigue Resistance ◽  
Fatigue Testing ◽  
Pedicle Screw Fixation ◽  
Screw Loosening ◽  
General Technique ◽  
Screw Augmentation ◽  
Pmma Bone Cement ◽  
Pedicle Screw Loosening

Pedicle screw loosening at the bone–screw interface is the main complication in pedicle screw fixation. The transpedicular polymethylmethacrylate screw augmentation technique has recently become the general technique used to re-operatively overcome pedicle screw loosening. This study investigates the fatigue resistance of PMMA bone cement augmentation. Twenty-seven porcine thoracic vertebral bodies were collected. The BMD was measured using dual X-ray absorptiometry. Each vertebral body was instrumented with one pedicle screw and mounted in a material testing system. Fatigue testing was performed by implementing a cranio-caudal sinusoidal, cyclic (5[Formula: see text]Hz) load. This study shows that transpedicular pedicle screw augmentation with PMMA exhibits similar fatigue resistance as traditional pedicle screw implantation. However, in histomophometrical analysis, the transpedicular pedicle screw augmentation with PMMA has greater anti-deformation capacity than traditional pedicle screw implantation. Transpedicular pedicle screw augmentation with PMMA improves more screw holding power to prevent pedicle screw loosening.

Diet-related changes in mechanical properties of rat vertebrae

1992 ◽  
Vol 262 (2) ◽  
pp. R318-R321 ◽  
Author(s):  
G. J. Salem ◽  
R. F. Zernicke ◽  
R. J. Barnard
Keyword(s):  
Mechanical Properties ◽  
Vertebral Body ◽  
Calcium Metabolism ◽  
Bone Mineralization ◽  
Maximum Load ◽  
Control Group ◽  
Buffer Solution ◽  
Cross Sectional ◽  
Lumbar Vertebral Body ◽  
Significant Difference

High fat and sucrose (HFS) diets may induce glucose intolerance, alter calcium metabolism, and lead to deficits in bone mineralization, development, and mechanical properties. To determine the mechanical and structural consequences of a HFS diet on rapidly growing vertebrae, female Sprague-Dawley rats (8 wk) were assigned randomly (2:1) either to a control group (n = 20) fed a low-fat complex-carbohydrate diet or an experimental group (n = 10) fed a HFS diet for 10-12 wk. The sixth lumbar vertebral body (L6) was isolated from the pedicles, morphological measures were taken, and compression was tested at a fast strain rate, while immersed in a warmed (37 degrees C) isotonic physiological buffer solution. No significant difference in body mass existed between HFS and control groups; nevertheless, HFS L6 cross-sectional areas, lengths, and volumes were significantly smaller than controls. The HFS L6 also had significantly lower mechanical properties, including initial maximum load, energy at initial maximum load, and strain energy density at initial maximum load. Diets high in sucrose and fat content have been associated with changes in calcium metabolism, and the results of the current study suggest that in immature vertebrae, a HFS diet may adversely affect vertebral body mechanical integrity and strength.

Hounsfield unit of screw trajectory as a predictor of pedicle screw loosening after single level lumbar interbody fusion

2018 ◽  
Vol 23 (5) ◽  
pp. 734-738 ◽  
Author(s):  
Yusuke Sakai ◽  
Shota Takenaka ◽  
Yohei Matsuo ◽  
Hiroyasu Fujiwara ◽  
Hirotsugu Honda ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Interbody Fusion ◽  
Hounsfield Unit ◽  
Lumbar Interbody Fusion ◽  
Screw Loosening ◽  
Single Level ◽  
Pedicle Screw Loosening

Pedicle screw loosening is correlated to chronic subclinical deep implant infection: a retrospective database analysis

2018 ◽  
Vol 27 (10) ◽  
pp. 2529-2535 ◽  
Author(s):  
Lukas Leitner ◽  
Isabella Malaj ◽  
Patrick Sadoghi ◽  
Florian Amerstorfer ◽  
Mathias Glehr ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Screw Loosening ◽  
Database Analysis ◽  
Implant Infection ◽  
Retrospective Database Analysis ◽  
Pedicle Screw Loosening ◽  
Retrospective Database
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