Occipito-Cervical Stabilization Using Occipital Condyle Screw

NCT03250611 | Unknown

• 1 other identifier: OC.Screw
• Study Type: interventional
• Target: 20
• Locations: 0 countries
• Sites: N/A

Brief Summary

The Occipito-Cervical (OC) junction is the most cephalad portion of the spinal axis, with anatomical osseous complex that allows significant mobility while maintaining biomechanical stability. OC instability is a rare disorder with potentially life-threatening consequences. Instability may manifest as disabling pain, cranial nerve dysfunction, paralysis, or even sudden death. The most common acute presentation is secondary to major trauma. Other pathologic processes that may lead to chronic instability include rheumatoid arthritis, infections, tumors, and even congenital malformations; OC fusion in aforementioned cases each according is then indicated. Stabilization of the OC junction remains a challenge, owing to the regional anatomy and poor occipital bone purchase. OC stabilization techniques have undergone continuous refinement. Early techniques involving simple posterior only bone grafts demonstrated a high rate of failure and have largely been replaced by rigid posterior fixation systems using rods/screws or plates, providing superior biomechanical stability and higher rates of fusion. One of the very modern modalities of fixation methods is the Occipital Condyle Screw (OCS) as a sole cranial anchor; believing that decreasing the length of lever arm of the construct, increasing the length of the screw purchase, and decreasing stresses addressed on the rod with no need to excessively bend it for the occipital slope may enhance the construct rigidity, and leaving a greater clear metal-free area of the occiput for graft contact may have a real potential benefits in fusion rates.

Conditions

Cervical Instabilities Spine

Keywords

Occipital condyle; Occipital condyle screw

Outcome Measures

Primary Outcomes (1)

• CT based classification for assessment of biological graft fusion

  A new assessment method of bony union using high-speed spiral CT imaging is proposed which reflects the gradually increasing biological stability of the construct. Grade I (complete fusion) implies cortical union of the allograft and central trabecular continuity. Grade II (partial fusion) implies cortical union of the structural allograft with partial trabecular incorporation. Grade III (unipolar pseudarthrosis) denotes superior or inferior cortical non-union of the central allograft with partial trabecular discontinuity centrally and Grade IV (bipolar pseudarthrosis) suggests both superior and inferior cortical non-union with a complete lack of central trabecular continuity.

  At 6 months postoperative

Secondary Outcomes (4)

• Visual Analogue Scale for Pain (VAS Pain)

  Baseline measure, then at 2 weeks, 3 months and 6 months postoperative

• Neck Disability Index (NDI)

  Baseline measure, then at 2 weeks, 3 months and 6 months postoperative

• American Spinal Injury Association Score (ASIAs)

  Baseline and 3 months postoperative

• Modified Japanese Orthopaedic Association Cervical Spondylotic Myelopathy Score (mJOA.CSM)

  Baseline and 3 months postoperative

Study Arms (1)

Occipito-Cervical Instability

EXPERIMENTAL

Stabilization of the occipito-cervical junction by Occipital Condyle Screw (OCS) as a sole cranial anchor, with posterior bone graft.

Procedure: Occipital Condyle Screw

Interventions

Occipital Condyle Screw PROCEDURE

Occipito-Cervical Screw-Rod Fixation Technique

Occipito-Cervical Instability

Eligibility Criteria

• Age: 16 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients with occipito-cervical instability of any cause, indicated for occipito-cervical fusion

You may not qualify if:

• Fractured occipital condyle
• Congenital malformation of occipital condyle
• Congenital anomaly of the horizontal segment of the vertebral artery

Sponsors & Collaborators

• Assiut University: lead

Related Publications (6)

• Uribe JS, Ramos E, Vale F. Feasibility of occipital condyle screw placement for occipitocervical fixation: a cadaveric study and description of a novel technique. J Spinal Disord Tech. 2008 Dec;21(8):540-6. doi: 10.1097/BSD.0b013e31816d655e.

  PMID: 19057245 BACKGROUND

• Uribe JS, Ramos E, Youssef AS, Levine N, Turner AW, Johnson WM, Vale FL. Craniocervical fixation with occipital condyle screws: biomechanical analysis of a novel technique. Spine (Phila Pa 1976). 2010 Apr 20;35(9):931-8. doi: 10.1097/BRS.0b013e3181c16f9a.

  PMID: 20375778 BACKGROUND

• Uribe JS, Ramos E, Baaj A, Youssef AS, Vale FL. Occipital cervical stabilization using occipital condyles for cranial fixation: technical case report. Neurosurgery. 2009 Dec;65(6):E1216-7; discussion E1217. doi: 10.1227/01.NEU.0000349207.98394.FA.

  PMID: 19934947 BACKGROUND

• La Marca F, Zubay G, Morrison T, Karahalios D. Cadaveric study for placement of occipital condyle screws: technique and effects on surrounding anatomic structures. J Neurosurg Spine. 2008 Oct;9(4):347-53. doi: 10.3171/SPI.2008.9.10.347.

  PMID: 18939920 BACKGROUND

• Ahmadian A, Dakwar E, Vale FL, Uribe JS. Occipitocervical fusion via occipital condylar fixation: a clinical case series. J Spinal Disord Tech. 2014 Jun;27(4):232-6. doi: 10.1097/BSD.0b013e31825bfeea.

  PMID: 24866907 BACKGROUND

• Tan GH, Goss BG, Thorpe PJ, Williams RP. CT-based classification of long spinal allograft fusion. Eur Spine J. 2007 Nov;16(11):1875-81. doi: 10.1007/s00586-007-0376-0. Epub 2007 May 12.

  PMID: 17497188 BACKGROUND

Study Officials

• Mohamed El-Meshtawy, MD

  Assiut University

  STUDY DIRECTOR

Central Study Contacts

Ahmed Shawky, MD

CONTACT

+201010212222; ahsh313@yahoo.com

Muhammad Almessry, M.Sc.

CONTACT

+201007262147; dr.muhammad.orthospine@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal investigator

Study Record Dates

• First Submitted: August 10, 2017
• First Posted: August 15, 2017
• Study Start: September 1, 2017
• Primary Completion: June 1, 2019
• Study Completion: January 1, 2020
• Last Updated: August 15, 2017

Record last verified: 2017-08

Data Sharing

• IPD Sharing: Will not share