Scientific Articles   |    
Effect of Corticosteroids on the Biomechanical Strength of Rat Rotator Cuff Tendon
David K. Mikolyzk, MD1; Anthony S. Wei, MD1; Pietro Tonino, MD1; Guido Marra, MD1; Denis A. Williams, MD1; Ryan D. Himes, BS1; Frederick H. Wezeman, PhD1; John J. Callaci, PhD1
1 Department of Orthopaedic Surgery and Rehabilitation, Loyola University Medical Center, 2160 South First Avenue, Maguire Building, Suite 1700, Maywood, IL 60153. E-mail address for D.K. Mikolyzk: dmikoly@lumc.edu
View Disclosures and Other Information
Disclosure: In support of their research for or preparation of this work, one or more of the authors received, in any one year, outside funding or grants of less than $10,000 from the Walgreen Foundation. Neither they nor a member of their immediate families received 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, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.
Investigation performed at the Department of Orthopaedic Surgery and Rehabilitation, Loyola University Medical Center, Maywood, Illinois

The Journal of Bone and Joint Surgery, Inc.
J Bone Joint Surg Am, 2009 May 01;91(5):1172-1180. doi: 10.2106/JBJS.H.00191
5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case


Background: The effect of corticosteroids on tendon properties is poorly understood, and current data are contradictory and diverse. The biomechanical effect of steroids on rotator cuff tendon has not been studied, to our knowledge. The current study was undertaken to characterize the biomechanical effects of corticosteroid exposure on both uninjured and injured rat rotator cuff tendon.

Methods: One hundred and twenty-three male Sprague-Dawley rats were randomly assigned to four groups: control (C), tendon injury (I), steroid exposure (S), and tendon injury plus steroid exposure (I+S). Unilateral tendon injuries consisting of a full-thickness defect across 50% of the total width of the infraspinatus tendon were created. Steroid treatment consisted of a single dose of methylprednisolone placed into the subacromial space. At one, three, and five weeks postoperatively, the shoulders were harvested and the infraspinatus tendon was subjected to biomechanical testing. Two specimens from each group were used for histological analysis.

Results: At one week, maximum load, maximum stress, and stiffness were all significantly decreased in Group S compared with the values in Group C. Mean maximum load decreased from 37.9 N in Group C to 27.5 N in Group S (p < 0.0005). Mean maximum stress decreased from 18.1 MPa in Group C to 13.6 MPa in Group S (p < 0.0005). Mean stiffness decreased from 26.3 N/mm in Group C to 17.8 N/mm in Group S (p < 0.0005). At one week, mean maximum stress in Group I+S (17.0 MPa) was significantly decreased compared with the value in Group I (19.5 MPa) (p < 0.0005). At both the three-week and the five-week time point, there were no significant differences between Group C and Group S or between Group I and Group I+S with regard to mean maximum load, maximum stress, or stiffness. Histological analysis showed fat cells and collagen attenuation in Groups S and I+S. These changes appeared to be transient.

Conclusions: A single dose of corticosteroids significantly weakens both intact and injured rat rotator cuff tendons at one week. This effect is transient as the biomechanical properties of the steroid-exposed groups returned to control levels by three weeks.

Clinical Relevance: Our findings in this rat model suggest that a single corticosteroid dose has significant short-term effects on the biomechanical properties of both injured and uninjured rotator cuff tendon. These effects should be weighed against any potential benefit prior to administering a subacromial corticosteroid injection.

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


    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
    Blepharitis. -American Academy of Ophthalmology | 6/5/2009
    Results provided by:
    Clinical Trials
    Readers of This Also Read...
    JBJS Jobs
    Louisiana - Ochsner Health System
    Georgia - Choice Care Occupational Medicine & Orthopaedics
    NY - Icahn School of Medicine at Mount Sinai
    WV - Charleston Area Medical Center