The Optimal Screw Length of Lumbar Pedicle Screws during Minimally Invasive Surgery Fixation: A Computed Tomography-Guided Evaluation of 771 Screws

Chua, Min Jia; Siddiqui, Shiblee; Yu, Chun Sing; Nolan, Colum Patrick; Oh, Jacob Yoong-Leong

doi:10.31616/asj.2018.0276

Cited by 10 publications

(7 citation statements)

References 8 publications

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“…In a non-fractured vertebra, the pullout strength of the pedicle screws was responsible for 60% of the anchoring inside the pedicle and 15%-20% at the cancellous bone in the vertebral body. Chua et al 32 stated in their study that pedicle screws should not exceed 85% of the vertebral body length on the lateral view for L1 to reduce the risk of an anterior cortical breach and damage to nearby neurovascular structures while maximizing pedicle screw purchase for fixation durability. In these studies, they only analyzed a single segment.…”

Section: Discussionmentioning

confidence: 99%

The effect of the size of pedicle screw on the long-term radiological and clinical results of short-segment posterior instrumentation in the management of thoracolumbar vertebral fractures

Öztürk,

Süer,

Aydemir

et al. 2024

Acta Orthopaedica et Traumatologica Turcica

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Objective: It was aimed at evaluating the effect of the size of the pedicle screw placed on the fractured vertebra on the long-term radiological and clinical results of short-segment posterior instrumentation applied in the surgical treatment of thoracolumbar vertebral fractures. Methods: This retrospective study included 36 patients who underwent short-segment posterior instrumentation surgery for a single-level thoracolumbar (T11-L2) fracture between January 2015 and March 2021. The patients included in the study were divided into 2 groups according to the size of the pedicle screw placed in the fractured vertebra (group A: intermediate screw 4.5 mm, ≤35 mm + less than 50% of the vertebral corpus length, m/f: 13/4, n: 17, age: 36.5; group B: intermediate screw 5.5 mm, ≥40 mm + more than 70% of the vertebral corpus length, m/f: 11/8, n: 19, age: 42.6). All patients were periodically evaluated clinically and radiologically. Vertebral compression angle (VCA), anterior and posterior vertebral body height (ABH-PBH), intraoperative parameters (instrumentation time and intraoperative fluoroscopy number), and complications were compared between the 2 groups. Results: Both groups were comparable with respect to age, sex, level of injury, AO classification, mechanism of injury, and American Spinal Cord Injury Association impairment scale. Restoration of VCA and vertebral corpus heights was achieved sufficiently in both groups after operation ( P < .0001). There was no significant difference between the 2 groups in terms of early postoperative VCA, VCA measured at final follow-up, or loss of correction in VCA. At the last follow-up, PBH was statistically significantly better preserved in group B ( P = .0424). There was no difference between the 2 groups in terms of operation time and the number of intraoperative fluoroscopies. Implant failure was observed in 1 patient in group A. Conclusion: This study has revealed that using a long, thick pedicle screw placed in the fractured vertebra can better preserve the PBH at the final follow-up. No correlation was found between the size of the intermediate screw and the preservation of the correction in the postoperative vertebral heights and VCA during the follow-up. Level of Evidence Level III, Therapeutic Study.

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Section: Discussionmentioning

confidence: 99%

The effect of the size of pedicle screw on the long-term radiological and clinical results of short-segment posterior instrumentation in the management of thoracolumbar vertebral fractures

Öztürk,

Süer,

Aydemir

et al. 2024

Acta Orthopaedica et Traumatologica Turcica

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“…20 Chua et al has recommended the optimal length if pedicle screws up to 85% of the vertebral body for the L1 vertebra, 80% for L2 to L4, and 75% for L5 for optimal purchase and fixation stability without the risk of breaching the anterior cortex. 21 We also advocate the use of CT scan images to assess the anatomy of the S1 pedicle prior to deciding on the entry point for the pedicle screw. Similar conclusions have also been offered in the published literature.…”

Section: Discussionmentioning

confidence: 99%

New classification of S1 pedicle morphometry impacting pedicle screw insertion technique

Tiwari¹,

Sonone²,

Jaiswal³

2022

Int J Res Orthop

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Background: The conventional entry point for the S1 pedicle screw insertion has been described as ‘at the base of and lateral to the superior S1 superior facet’. However, many orthopaedic surgeons complain that this technique is extremely demanding and is faced with many challenges in execution. Therefore, alternative entry points and modifications of existing techniques are explored for a greater convenience.Methods: We conducted a survey amongst 136 spine surgeons on the technical difficulties faced during insertion of the S1 pedicle screw. We also classified the S1 pedicles based by measuring their geometric parameters on 100 random computed tomography (CT) images.Results: The S1 pedicle entry technique was considered to be the most difficult and challenging by the orthopaedic surgeons in our survey due to an inadequate medial angulation due to paraspinal muscle mass tension and an overhanging iliac crest. This could be explained by the hourglass shaped pedicle (type 3) with a desired medial angle more 50 degrees (type III) observed as the most common S1 pedicle in the study population. To overcome this limitation, most of them preferred a tri-corticate approach.Conclusions: A more lateral entry point and a longer screw might be considered as solutions for a better and safer S1 pedicle entry. Also, the use of pre-operative CT can be considered to visualize the type of S1 pedicle and hence, decide on the most appropriate technique of screw insertion.

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“…Screw size should be determined based on the screw fitness in the pedicle and screw insertion depth in the vertebral body according to each vertebral anatomy, not uniformly or by surgeon’s preference. Chua et al 19 performed radiological analysis to ascertain the optimal screw length for lumbar pedicle screw placement and recommended that screws should not exceed 80% of the vertebral body length for L2-L4 and 75% for L5 to minimize the risk of anterior cortical breach. From this perspective, the cutoff value of 54.2% for %depth obtained in the present study is thus within an acceptable level of safety.…”

Section: Discussionmentioning

confidence: 99%

Influence of Pedicle Screw Insertion Depth on Posterior Lumbar Interbody Fusion: Radiological Significance of Deeper Screw Placement

Matsukawa

Konomi

Matsubayashi

et al. 2022

Global Spine Journal

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Study Design Retrospective case series. Objectives To investigate the influence of screw size on achieving bone fusion in posterior lumbar interbody fusion (PLIF). Methods In total, 137 consecutive patients with L4 degenerative spondylolisthesis who underwent single-level PLIF at L4-L5 were evaluated. Factors investigated for their contribution to bone fusion included: 1) age, 2) sex, 3) body mass index, 4) bone mineral density, 5) intervertebral mobility, 6) screw diameter, 7) screw length, 8) screw fitness in the pedicle (%fill), 9) screw depth in the vertebra (%depth), 10) screw angle, 11) facetectomy, 12) crosslink connector, and 13) cage material. Results Bone fusion was confirmed in 88.2% of patients. The comparison between fusion (+) and fusion (-) groups showed no significant differences in screw size. The %fill and %length were significantly greater in the fusion (+) group than in the fusion (-) group (%fill: 58.5% ± 7.5% vs 52.3% ± 7.3%, respectively, P = .005; %depth: 59.8% ± 9.7% vs 50.3% ± 13.8%, respectively, P = .025). Multivariate logistic regression analysis revealed that %fill (odds ratio [OR]= 1.11, P = .025) and %depth (OR = 1.09, P = .003) were significant independent factors affecting bone fusion. Receiver operating characteristic curve analyses identified a %fill of 60.0% and a %depth of 54.2% as optimal cutoff values for achieving bone fusion Conclusions Screw size should be determined based on the screw fitness in the pedicle (%fill > 60%) and screw insertion depth in the vertebral body (%depth > 54.2%) according to individual vertebral anatomy in L4-L5 PLIF.

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The Optimal Screw Length of Lumbar Pedicle Screws during Minimally Invasive Surgery Fixation: A Computed Tomography-Guided Evaluation of 771 Screws

Cited by 10 publications

References 8 publications

The effect of the size of pedicle screw on the long-term radiological and clinical results of short-segment posterior instrumentation in the management of thoracolumbar vertebral fractures

The effect of the size of pedicle screw on the long-term radiological and clinical results of short-segment posterior instrumentation in the management of thoracolumbar vertebral fractures

New classification of S1 pedicle morphometry impacting pedicle screw insertion technique

Influence of Pedicle Screw Insertion Depth on Posterior Lumbar Interbody Fusion: Radiological Significance of Deeper Screw Placement

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