Surgical Techniques   |    
Determination of Correct Implant Size in Radial Head Arthroplasty to Avoid OverlengtheningSurgical Technique
George S. Athwal, MD, FRCSC1; Simon G. Frank, MD1; Ruby Grewal, MD, MSc, FRCSC1; Kenneth J. Faber, MD, MHPE, FRCSC1; James Johnson, Ph D1; Graham J.W. King, MD, MSc, FRCSC1
1 Hand and Upper Limb Centre, St. Joseph's Health Care, 268 Grosvenor Street, London, ON N6A 4L6, Canada. E-mail address for G.S. Athwal: gathwal@uwo.ca
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 in excess of $10,000 from the Canadian Orthopaedic Foundation, the Alexandra Kirkley Young Investigator Award. In addition, one or more of the authors or a member of his or her immediate family received, in any one year, payments or other benefits in excess of $10,000 or a commitment or agreement to provide such benefits from a commercial entity (Wright Medical Technology, payable to research fund).

Investigation performed at the Hand and Upper Limb Centre, St. Joseph's Health Care, University of Western Ontario, London, Ontario, Canada
The original scientific article in which the surgical technique was presented was published in JBJS Vol. 91-A, pp. 1738-46, July 2009
The line drawings in this article are the work of Jennifer Fairman (jfairman@fairmanstudios.com).

Copyright ©2010 American Society for Journal of Bone and Joint Surgery, Inc.
J Bone Joint Surg Am, 2010 Sep 01;92(Supplement 1 Part 2):250-257. doi: 10.2106/JBJS.J.00356
5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case



Insertion of a radial head implant that results in radial overlengthening has been associated with altered elbow kinematics, increased radiocapitellar joint forces, capitellar erosions, early-onset arthritis, and loss of elbow flexion. The purpose of this study was to identify clinical and radiographic features that may be used to diagnose overlengthening of the radius intraoperatively and on postoperative radiographs.


Radial head implants of varying thicknesses were inserted into seven cadaver specimens, which were then assessed clinically and radiographically. Eight stages were examined: the intact specimen (stage 1); repair of the lateral collateral ligament (stage 2); radial head resection with repair of the lateral collateral ligament (stage 3); insertion of an implant of the correct thickness (stage 4); and insertion of an implant that resulted in radial overlengthening of 2 mm (stage 5), 4 mm (stage 6), 6 mm (stage 7), or 8 mm (stage 8). The specimens were tested with and without muscle loading to simulate resting muscle tone and surgical paralysis, respectively. At each stage, radiographs were made to measure the ulnohumeral joint space and the lateral ulnohumeral joint was visually assessed.


We identified no difference, with regard to medial ulnohumeral joint incongruity as seen radiographically, among stages 1 through 6 during the tests with muscle loading. A significant difference in medial ulnohumeral joint incongruity was found in stages 7 (p = 0.003) and 8 (p < 0.001). The clinical (visually assessed) lateral ulnohumeral joint space gap was negligible in stages 1 through 4 but increased significantly at all stages involving overlengthening (gross gap, 0.9 mm with 2 mm of erlengthening [p = 0.005], 2.3 mm with 4 mm of overlengthening [p < 0.001], 3.4 mm with 6 mm [p < 0.001], and 4.7 mm with 8 mm [p < 0.001]).


Incongruity of the medial ulnohumeral joint becomes apparent radiographically only after overlengthening of the radius by =6 mm. Intraoperative visualization of a gap in the lateral ulnohumeral joint is a reliable indicator of overlengthening following the insertion of a radial head prosthesis.


This in vitro study indicates that the clinical (visual) observation of a lateral ulnohumeral joint gap is a reliable indicator of overlengthening following implantation of a radial head prosthesis. In contrast, radiographic measurements are relatively insensitive and cannot reliably demonstrate overlengthening of <6 mm.


"Determination of Correct Implant Size in Radial Head Arthroplasty to Avoid Overlengthening" (2009;91:1738-46).

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
    Clinical Trials
    Readers of This Also Read...
    JBJS Jobs
    Virginia - OrthoVirginia
    Massachusetts - Boston Medical Center and Boston University School of Medicine
    LA - Ochsner Health System
    OK - The University of Oklahoma