This Article Full Text Full Text (PDF) CME: Take the exam for this article: CME 4: October, November, December 2007 (publication date January 4, 2008; ... Letters to the Editor: Submit a response Alert me when this article is cited Alert me when Letters to the Editor are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My File Cabinet Download to citation manager Reprints and Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Rodeo, S. A. Articles by Atkinson, B. L. Search for Related Content PubMed PubMed Citation Articles by Rodeo, S. A. Articles by Atkinson, B. L. Related Collections Shoulder Social Bookmarking             What's this?

Biologic Augmentation of Rotator Cuff Tendon-Healing with Use of a Mixture of Osteoinductive Growth Factors^*

¹ The Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021. E-mail address for S.A. Rodeo: rodeos{at}hss.edu

Investigation performed at The Laboratory for Soft Tissue Research and the Sports Medicine and Shoulder Service, The Hospital for Special Surgery, New York, NY

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 Sulzer Biologics. 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 of less than $10,000 or a commitment or agreement to provide such benefits from a commercial entity (Sulzer Biologics). 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.

^* The paper was read, in part, at the Annual Meeting of the Orthopaedic Research Society, Dallas, February 2002.

Methods: Seventy-two skeletally mature sheep underwent detachment of the infraspinatus tendon followed by immediate repair. The animals received one of three treatments at the tendon-bone interface: (1) an osteoinductive bone protein extract on a Type-I collagen sponge carrier, (2) the collagen sponge carrier alone, and (3) no implant. The animals were killed at six and twelve weeks, and the repaired rotator cuff was evaluated with use of magnetic resonance imaging, plain radiographs, histologic analysis, and biomechanical testing.

Results: A gap consistently formed between the end of the repaired tendon and bone in this model, with reparative scar tissue and new bone spanning the gap. Magnetic resonance imaging showed that the volume of newly formed bone (p < 0.05) and soft tissue (p < 0.05) in the tendon-bone gap were greater in the growth factor-treated animals compared with the collagen sponge control group at both time-points. Histologic analysis showed a fibrovascular tissue in the interface between tendon and bone, with a more robust fibrocartilage zone between the bone and the tendon in the growth factor-treated animals. The repairs that were treated with the osteoinductive growth factors had significantly greater failure loads at six weeks and twelve weeks (p < 0.05); however, when the data were normalized by tissue volume, there were no differences between the groups, suggesting that the treatment with growth factor results in the formation of poor-quality scar tissue rather than true tissue regeneration. The repairs that were treated with the collagen sponge carrier alone had significantly greater stiffness than the growth factor-treated group at twelve weeks (p = 0.005).

Conclusions: This model tests the effects of growth factors on scar tissue formation in a gap between tendon and bone. The administration of osteoinductive growth factors resulted in greater formation of new bone, fibrocartilage, and soft tissue, with a concomitant increase in tendon attachment strength but less stiffness than repairs treated with the collagen sponge carrier alone.

Clinical Relevance: This study is the first, as far as we know, to demonstrate the possibility of increasing tissue formation in a tendon-bone gap with use of a biologic agent. It shows the importance of the use of magnetic resonance imaging to evaluate the repaired tendon, since the findings on gross observation and even histologic examination could easily be interpreted as representing an intact repair. Further studies with use of more clinically relevant models of tendon-bone repair may support the use of growth factors to improve clinical outcomes.

CiteULike    Connotea    Del.icio.us    Technorati    What's this?

Stanford University Libraries' HighWire Press (TM) assists in the publication of JBJS Online.
Copyright © 2007 by The Journal of Bone and Joint Surgery, Inc. Online ISSN: 1535-1386.
The Journal of Bone and Joint Surgery®, JBJS®, JB&JS®, and eJBJS® are registered in the U.S. Patent and Trademark Office.