Accuracy of Free-Hand Pedicle Screws in the Thoracic and Lumbar Spine: Analysis of 6816 Consecutive Screws

Parker, Scott L.; McGirt, Matthew J.; Farber, S. Harrison; Amin, Anubhav G.; Rick, Anne-Marie; Suk, Ian; Bydon, Ali; Sciubba, Daniel M.; Wolinsky, Jean Paul; Gokaslan, Ziya L.; Witham, Timothy F.

doi:10.1227/neu.0b013e3181fdfaf4

Cited by 231 publications

(185 citation statements)

References 20 publications

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“…4 Since the inception of pedicle screws for spinal stabilization, various techniques have been used to guide and verify screw placement. 5,6 Examples of these techniques include the use of anatomic landmarks, 7 laminotomy for palpation of the pedicle, plain radiography, fluoroscopic imaging (standard or image guidance), 8,9 and CT image guidance. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Extensive literature has been published describing the technique, benefits, and drawbacks of each method, as well as comparisons between different approaches.…”

Section: Introductionmentioning

confidence: 99%

Reliability of the Planned Pedicle Screw Trajectory versus the Actual Pedicle Screw Trajectory using Intra-operative 3D CT and Image Guidance

et al. 2016

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Section: Introductionmentioning

confidence: 99%

Reliability of the Planned Pedicle Screw Trajectory versus the Actual Pedicle Screw Trajectory using Intra-operative 3D CT and Image Guidance

et al. 2016

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“…27 Technical studies on the use of freehand pedicle screw placement in the thoracic spine are few and limited.…”

Section: Discussionmentioning

confidence: 99%

Freehand thoracic pedicle screw technique using a uniform entry point and sagittal trajectory for all levels: preliminary clinical experience

Fennell¹,

Palejwala²,

Skoch³

et al. 2014

SPI

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Object Experience with freehand thoracic pedicle screw placement is well described in the literature. Published techniques rely on various starting points and trajectories for each level or segment of the thoracic spine. Furthermore, few studies provide specific guidance on sagittal and axial trajectories. The goal of this study was to propose a uniform entry point and sagittal trajectory for all thoracic levels during freehand pedicle screw placement and determine the accuracy of this technique. Methods The authors retrospectively reviewed postoperative CT scans of 33 consecutive patients who underwent open, freehand thoracic pedicle-screw fixation using a uniform entry point and sagittal trajectory for all levels. The same entry point for each level was defined as a point 3 mm caudal to the junction of the transverse process and the lateral margin of the superior articulating process, and the sagittal trajectory was always orthogonal to the dorsal curvature of the spine at that level. The medial angulation (axial trajectory) was approximately 30° at T-1 and T-2, and 20° from T-3 to T-12. Breach was defined as greater than 25% of the screw diameter residing outside of the pedicle or vertebral body. Results A total of 219 thoracic pedicle screws were placed with a 96% accuracy rate. There were no medial breaches and 9 minor lateral breaches (4.1%). None of the screws had to be repositioned postoperatively, and there were no neurovascular complications associated with the breaches. Conclusions It is feasible to place freehand thoracic pedicle screws using a uniform entry point and sagittal trajectory for all levels. The entry point does not have to be adjusted for each level as reported in existing studies, although this technique was not tested in severe scoliotic spines. While other techniques are effective and widely used, this particular method provides more specific parameters and may be easier to learn, teach, and adopt.

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“…The rate of return to surgery for screw malposition also varied from 0.117% to 0.483% of screws placed (Table 3). 3,14,20,27,36,38 The reported outcomes include the anticipated cost savings from implant costs, potential number of malpositioned screws prevented, and cost savings from averted returns to surgery for screw malposition. The total annual cost savings (in 2009 US dollars) were estimated based on the implant costs and averted returns to surgery.…”

Section: Methodsmentioning

confidence: 99%

“…However, return to surgery for implant malposition is well-reported in the literature, affecting up to 0.66% to 4.3% of patients. 3,7,14,20,38 Thus, if clinically equivalent, using fewer screws overall may incrementally improve patient safety with fewer malpositioned screws and thus fewer returns to the operating room for screw malposition. This may subsequently reduce the cost of scoliosis surgery due to fewer surgical returns for implant malposition.…”

mentioning

confidence: 99%

What would be the annual cost savings if fewer screws were used in adolescent idiopathic scoliosis treatment in the US?

Larson

Polly

Ackerman

et al. 2016

SPI

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OBJECT There is substantial heterogeneity in the number of screws used per level fused in adolescent idiopathic scoliosis (AIS) surgery. Assuming equivalent clinical outcomes, the potential cost savings of using fewer pedicle screws were estimated using a medical decision model with sensitivity analysis. METHODS Descriptive analyses explored the annual costs for 5710 AIS inpatient stays using discharge data from the 2009 Kids’ Inpatient Database (Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality), which is a national all-payer inpatient database. Patients between 10 and 17 years of age were identified using the ICD-9-CM code for idiopathic scoliosis (737.30). All inpatient stays were assumed to represent 10-level fusions with pedicle screws for AIS. High screw density was defined at 1.8 screws per level fused, and the standard screw density was defined as 1.48 screws per level fused. The surgical return for screw malposition was set at $23,762. A sensitivity analysis was performed by varying the cost per screw ($600–$1000) and the rate of surgical revisions for screw malposition (0.117%–0.483% of screws; 0.8%–4.3% of patients). The reported outcomes include estimated prevented malpositioned screws (set at 5.1%), averted revision surgeries, and annual cost savings in 2009 US dollars, assuming similar clinical outcomes (rates of complications, revision) using a standard- versus high-density pattern. RESULTS The total annual costs for 5710 AIS hospital stays was $278 million ($48,900 per patient). Substituting a high for a standard screw density yields 3.2 fewer screws implanted per patient, with 932 malpositioned screws prevented and 21 to 88 revision surgeries for implant malposition averted, and a potential annual cost savings of $11 million to $20 million (4%–7% reduction in the total cost of AIS hospitalizations). CONCLUSIONS Reducing the number of screws used in scoliosis surgery could potentially decrease national AIS hospitalization costs by up to 7%, which may improve the safety and efficiency of care. However, such a screw construct must first be proven safe and effective.

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Accuracy of Free-Hand Pedicle Screws in the Thoracic and Lumbar Spine: Analysis of 6816 Consecutive Screws

Cited by 231 publications

References 20 publications

Reliability of the Planned Pedicle Screw Trajectory versus the Actual Pedicle Screw Trajectory using Intra-operative 3D CT and Image Guidance

Reliability of the Planned Pedicle Screw Trajectory versus the Actual Pedicle Screw Trajectory using Intra-operative 3D CT and Image Guidance

Freehand thoracic pedicle screw technique using a uniform entry point and sagittal trajectory for all levels: preliminary clinical experience

What would be the annual cost savings if fewer screws were used in adolescent idiopathic scoliosis treatment in the US?

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