0
Scientific Articles   |    
A Comparison of the Microarchitectural Bone Adaptations of the Concave and Convex Thoracic Spinal Facets in Idiopathic Scoliosis
Kevin G. Shea, MD1; Tyler Ford, BS2; Roy D. Bloebaum, PhD2; Jacques D'Astous, MD3; Howard King, MD4
1 Intermountain Orthopaedics, 600 North Robbins Road, Suite 400, Boise, ID 83702. E-mail address: kgshea@aol.com
2 Bone and Joint Research Laboratory, Veterans Administration Salt Lake City Health Care System, Salt Lake City, UT 84148
3 Department of Orthopedics, University of Utah School of Medicine, 50 North Medical Drive, Salt Lake City, UT 84132
4 St. Luke's Children's Hospital, Bannock Avenue, Boise, ID 83702
View Disclosures and Other Information
The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.
Presented as a poster exhibit at the Annual Meetings of the Orthopaedic Research Society on February 13-17, 2002, in Dallas, Texas; the Pediatric Orthopaedic Society of North America on May 2-5, 2002, in Salt Lake City, Utah; and the Scoliosis Research Society on September 18-21, 2002, in Seattle, Washington.
Investigation performed at St. Luke's Children's Hospital, Boise, Idaho, the Shriners Hospital for Children, Salt Lake City, and the Bone and Joint Research Laboratory, Veterans Administration Hospital, Salt Lake City, Utah

The Journal of Bone and Joint Surgery, Incorporated
J Bone Joint Surg Am, 2004 May 01;86(5):1000-1006
5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

Abstract

Background: A limited number of studies have assessed the changes in bone microarchitecture in spinal facets with use of light microscopy but not with use of electron microscopy techniques. The purpose of this study was to analyze the facets in patients with scoliosis to determine whether there are differences in the bone microarchitecture of contralateral facets at the same anatomic level.

Methods: In eight patients undergoing posterior spinal arthrodesis for the treatment of idiopathic scoliosis, biopsy specimens of facet pairs at matched anatomic levels were obtained from three locations: (1) the curve apex, (2) one level cephalad to the apex, and (3) one level caudad to the apex. The facets were analyzed for cortical bone porosity and thickness with use of scanning electron microscopy and National Institutes of Health imaging software. The concave and convex facets were compared with use of a paired t test.

Results: The mean porosity (and standard deviation) for the concave and convex facets was 16.5% ± 5.8% and 24.1% ± 6.2%, respectively. Those on the convex side were significantly more porous than those on the concave side (p = 0.03). The mean cortical width for the concave and convex facets was 798 ± 266 µm and 377 ± 124 µm, respectively. The concave facets had a significantly thicker cortex than did the convex facets (p < 0.01).

Conclusions: These results suggest that scoliotic deformities apply eccentric forces to spinal facets and that the concave and convex portions of the curve are subject to compression and tension forces, respectively. This analysis complements previous investigations of bone microarchitecture in animal models with use of a known compression-tension environment, and it suggests that the spinal facets remodel in a manner consistent with Wolff's law.

Clinical Relevance: Future studies of human spinal facets in scoliosis offer the opportunity to further define the microarchitectural response of human bone. Additional study will be necessary to determine whether these eccentric microarchitectural changes represent a secondary response to abnormal loading in the spine or whether an underlying pathological process in bone is a primary factor in the generation of scoliotic deformities. Further understanding of bone-remodeling in scoliosis may help to validate animal models and provide insight into the pathophysiology of scoliosis.

Figures in this Article
    Sign In to Your Personal ProfileSign In To Access Full Content
    Not a Subscriber?
    Get online access for 30 days for $35
    New to JBJS?
    Sign up for a full subscription to both the print and online editions
    Register for a FREE limited account to get full access to all CME activities, to comment on public articles, or to sign up for alerts.
    Register for a FREE limited account to get full access to all CME activities
    Have a subscription to the print edition?
    Current subscribers to The Journal of Bone & Joint Surgery in either the print or quarterly DVD formats receive free online access to JBJS.org.
    Forgot your password?
    Enter your username and email address. We'll send you a reminder to the email address on record.

     
    Forgot your username or need assistance? Please contact customer service at subs@jbjs.org. If your access is provided
    by your institution, please contact you librarian or administrator for username and password information. Institutional
    administrators, to reset your institution's master username or password, please contact subs@jbjs.org

    References

    Accreditation Statement
    These activities have been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint sponsorship of the American Academy of Orthopaedic Surgeons and The Journal of Bone and Joint Surgery, Inc. The American Academy of Orthopaedic Surgeons is accredited by the ACCME to provide continuing medical education for physicians.
    CME Activities Associated with This Article
    Submit a Comment
    Please read the other comments before you post yours. Contributors must reveal any conflict of interest.
    Comments are moderated and will appear on the site at the discretion of JBJS editorial staff.

    * = Required Field
    (if multiple authors, separate names by comma)
    Example: John Doe





    Related Content
    The Journal of Bone & Joint Surgery
    JBJS Case Connector
    Topic Collections
    Related Audio and Videos
    PubMed Articles
    Clinical Trials
    Readers of This Also Read...
    JBJS Jobs
    01/22/2014
    Pennsylvania - Penn State Milton S. Hershey Medical Center
    05/03/2012
    California - UCLA/OH Department of Orthopaedic Surgery
    11/15/2013
    Louisiana - Ochsner Health System
    12/31/2013
    S. Carolina - Department of Orthopaedic Surgery Medical Univerity of South Carlonina