MedPath

Accuracy And Safety of Trans Pedicular Screw Fixation of The Sub-axial Cervical Spine Using A Triad- Dependent Technique

Not yet recruiting
Conditions
Pedicle Screw
CPS
Registration Number
NCT05855642
Lead Sponsor
Assiut University
Brief Summary

The use of the pedicle screw system has become increasingly popular for treating an unstable cervical spine resulting from traumatic, degenerative, inflammatory, and neoplastic conditions. Because the cervical pedicle screw (CPS) has superior bio mechanical stability as the lateral mass screw or trans articular screw , pedicle screws allow for shorter instrumentation with improved spinal alignment. However, CPS insertion is technically demanding because of the anatomical variations in cervical pedicle size, lack of anatomical landmarks, small pedicle diameter, and the large transverse angle of cervical pedicles . The potential risk of injury to neurovascular structures, such as the vertebral artery, spinal cord, or nerve roots, caused by CPS remains a great concern. Therefore, accurate and safe CPS insertion techniques are necessary.

Detailed Description

The use of the pedicle screw system has become increasingly popular for treating an unstable cervical spine resulting from traumatic, degenerative, inflammatory, and neoplastic conditions. Because the cervical pedicle screw (CPS) has superior bio mechanical stability as the lateral mass screw or trans articular screw , pedicle screws allow for shorter instrumentation with improved spinal alignment. However, CPS insertion is technically demanding because of the anatomical variations in cervical pedicle size, lack of anatomical landmarks, small pedicle diameter, and the large transverse angle of cervical pedicles . The potential risk of injury to neurovascular structures, such as the vertebral artery, spinal cord, or nerve roots, caused by CPS remains a great concern. Therefore, accurate and safe CPS insertion techniques are necessary.

Although a number of studies have evaluated the morphometric of cervical pedicles to support accurate placement of pedicle screws , the results are inconclusive. Therefore, several techniques using lateral fluoroscopy , pedicle axis view by oblique fluoroscopy , laminoframinotomy and computer-assisted navigation systems for CPS insertion have been advocated. Determining an appropriate entry point for screw insertion as well as a proper trajectory angle of the screw on the axial plane is important for successful pedicle screw placement. Here, we present our method using a fashioned triad- dependent technique (TDT) which is a combination of three methods 1-preoperative planning of the selected pedicle using 3-diamentional multi-slice CT to measure pedicle transverse angle (PTA) , pedicle outer diameter(POD)and pedicle trajectory -contralateral lamina angle 2-AP and oblique fluoroscopy to determine pedicle entry point (PEP), parallelism to vertebral end plate and 4 direction cortical violation (medial, lateral, superior, inferior) 3-interlaminar confirmatory key hole for tactile cue of medial ,superior, and inferior borders of the pedicle and related nerve root to evaluate the accuracy and safety of pedicle screw placement in patients with sub axial cervical spine disorders treated using our method.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
20
Inclusion Criteria
  1. traumatic sub axial cervical spine injuries.
  2. degenerative cervical spine disorders necessitating cervical fusion
Exclusion Criteria
  1. congenital anomaly of the cervical spine
  2. scoliotic deformity of the cervical spine
  3. sever osteoporosis
  4. congenital malformation of the pedicle.

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Radiological accuracyImmediately post Operative

A. X-ray AP and lateral

B. MSCT: Placements of pedicle screws will be assessed using CT data and outcome-based classifications:

2 mm increment classification:

* Type 0 (good): Screw within the pedicle medullary canal.

* Type 1 (acceptable): Minimal penetration of the pedicle wall by the screw (\<2 mm of medial or lateral cortical perforation or anterior cortex perforation).

* Type 2 (unacceptable): Less than half of the diameter of the screw was outside the pedicle wall (2-4 mm of perforation).

* Type 3 (grievous): More than half of the diameter of the screw was outside the pedicle wall (\>4 mm of perforation) (spinal cord injury or screw abutting vertebral artery).

Secondary Outcome Measures
NameTimeMethod
© Copyright 2025. All Rights Reserved by MedPath