170
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Mineral Distributions at the Developing Tendon Enthesis

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Tendon attaches to bone across a functionally graded interface, “the enthesis”. A gradient of mineral content is believed to play an important role for dissipation of stress concentrations at mature fibrocartilaginous interfaces. Surgical repair of injured tendon to bone often fails, suggesting that the enthesis does not regenerate in a healing setting. Understanding the development and the micro/nano-meter structure of this unique interface may provide novel insights for the improvement of repair strategies. This study monitored the development of transitional tissue at the murine supraspinatus tendon enthesis, which begins postnatally and is completed by postnatal day 28. The micrometer-scale distribution of mineral across the developing enthesis was studied by X-ray micro-computed tomography and Raman microprobe spectroscopy. Analyzed regions were identified and further studied by histomorphometry. The nanometer-scale distribution of mineral and collagen fibrils at the developing interface was studied using transmission electron microscopy (TEM). A zone (∼20 µm) exhibiting a gradient in mineral relative to collagen was detected at the leading edge of the hard-soft tissue interface as early as postnatal day 7. Nanocharacterization by TEM suggested that this mineral gradient arose from intrinsic surface roughness on the scale of tens of nanometers at the mineralized front. Microcomputed tomography measurements indicated increases in bone mineral density with time. Raman spectroscopy measurements revealed that the mineral-to-collagen ratio on the mineralized side of the interface was constant throughout postnatal development. An increase in the carbonate concentration of the apatite mineral phase over time suggested possible matrix remodeling during postnatal development. Comparison of Raman-based observations of localized mineral content with histomorphological features indicated that development of the graded mineralized interface is linked to endochondral bone formation near the tendon insertion. These conserved and time-varying aspects of interface composition may have important implications for the growth and mechanical stability of the tendon-to-bone attachment throughout development.

          Related collections

          Most cited references38

          • Record: found
          • Abstract: found
          • Article: not found

          The outcome and repair integrity of completely arthroscopically repaired large and massive rotator cuff tears.

          The impact of a recurrent defect on the outcome after rotator cuff repair has been controversial. The purpose of this study was to evaluate the functional and anatomic results after arthroscopic repair of large and massive rotator cuff tears with use of ultrasound as an imaging modality to determine the postoperative integrity of the repair. Eighteen patients who had complete arthroscopic repair of a tear measuring >2 cm in the transverse dimension were evaluated at a minimum of twelve months after surgery and again at two years after surgery. The evaluation consisted of a standardized history and physical examination as well as calculation of the preoperative and postoperative shoulder scores according to the system of the American Shoulder and Elbow Surgeons. The strength of both shoulders was quantitated postoperatively with use of a portable dynamometer. Ultrasound studies were performed with use of an established and validated protocol at a minimum of twelve months after surgery. Recurrent tears were seen in seventeen of the eighteen patients. Despite the absence of healing at twelve months after surgery, thirteen patients had an American Shoulder and Elbow Surgeons score of >/=90 points. Sixteen patients had an improvement in the functional outcome score, which increased from an average of 48.3 to 84.6 points. Sixteen patients had a decrease in pain, and twelve had no pain. Although eight patients had preoperative forward elevation to /=90 points, and six patients had a score of /=80.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Repairs of the rotator cuff. Correlation of functional results with integrity of the cuff.

            We evaluated the results of 105 operative repairs of tears of the rotator cuff of the shoulder in eighty-nine patients at an average of five years postoperatively. We correlated the functional result with the integrity of the cuff, as determined by ultrasonography. Eighty per cent of the repairs of a tear involving only the supraspinatus tendon were intact at the time of the most recent follow-up, while more than 50 per cent of the repairs of a tear involving more than the supraspinatus tendon had a recurrent defect. Older patients and patients in whom a larger tear had been repaired had a greater prevalence of recurrent defects. At the time of the most recent follow-up, most of the patients were more comfortable and were satisfied with the result of the repair, even when they had sonographic evidence of a recurrent defect. The shoulders in which the repaired cuff was intact at the time of follow-up had better function during activities of daily living and a better range of active flexion (129 +/- 20 degrees compared with 71 +/- 41 degrees) compared with the shoulders that had a large recurrent defect. Similar correlations were noted for the range of active external and internal rotation and for strength of flexion, abduction, and internal rotation. In the shoulders in which the cuff was not intact, the degree of functional loss was related to the size of the recurrent defect.(ABSTRACT TRUNCATED AT 250 WORDS)
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              The anatomical basis for disease localisation in seronegative spondyloarthropathy at entheses and related sites.

              The 2 major categories of idiopathic inflammatory arthritis are rheumatoid arthritis and the seronegative spondyloarthropathies. Whilst the synovium is the primary site of joint disease in the former, the primary site in the latter is less well defined. However, it has recently been proposed that enthesitis-associated changes in the spondyloarthropathies are primary and that all other joint manifestations are secondary. Nevertheless, some of the sites of disease localisation have not been adequately explained in terms of enthesitis. This article summarises current knowledge of the structure, function, blood supply, innervation, molecular composition and histopathology of the classic enthesis (i.e. the bony attachment of a tendon or ligament) and introduces the concept of 'functional' and articular 'fibrocartilaginous' entheses. The former are regions where tendons or ligaments wrap-around bony pulleys, but are not attached to them, and the latter are synovial joints that are lined by fibrocartilage rather than hyaline cartilage. We describe how these 3 types of entheses relate to other, and how all are prone to pathological changes in spondyloarthropathy. We propose that the inflammatory responses characteristic of spondyloarthropathies are triggered at these seemingly diverse sites, in genetically susceptible individuals, by a combination of anatomical factors which lead to higher levels of tissue microtrauma, and the deposition of microbes.
                Bookmark

                Author and article information

                Contributors
                Role: Editor
                Journal
                PLoS One
                PLoS ONE
                plos
                plosone
                PLoS ONE
                Public Library of Science (San Francisco, USA )
                1932-6203
                2012
                9 November 2012
                : 7
                : 11
                : e48630
                Affiliations
                [1 ]Department of Orthopaedic Surgery, Washington University, St. Louis, Missouri, United States of America
                [2 ]Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri, United States of America
                [3 ]Department of Mechanical Engineering & Materials Science, Washington University, St. Louis, Missouri, United States of America
                [4 ]Center for Materials Innovation, Washington University, St. Louis, Missouri, United States of America
                [5 ]Department of Physics, Washington University, St. Louis, Missouri, United States of America
                University of Notre Dame, United States of America
                Author notes

                Competing Interests: The authors have declared that no competing interests exist.

                Conceived and designed the experiments: AS JP GG TD ST. Performed the experiments: AS JP TD. Analyzed the data: AS JP GG TD ST. Contributed reagents/materials/analysis tools: JP TD. Wrote the paper: AS JP GG TD ST.

                Article
                PONE-D-12-18011
                10.1371/journal.pone.0048630
                3494702
                23152788
                a87d10bb-07a1-45c3-8625-e232aa5bcc79
                Copyright @ 2012

                This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

                History
                : 22 June 2012
                : 3 October 2012
                Page count
                Pages: 11
                Funding
                The studies were funded by the National Institutes of Health (R01 AR055580), the National Science Foundation (CAREER 844607), and the Center for Materials Innovation at Washington University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
                Categories
                Research Article
                Biology
                Anatomy and Physiology
                Musculoskeletal System
                Bone
                Cartilage
                Developmental Biology
                Cell Differentiation
                Histology
                Molecular Cell Biology
                Extracellular Matrix
                Connective Tissue
                Extracellular Matrix Composition
                Materials Science
                Biomaterials
                Medicine
                Anatomy and Physiology
                Musculoskeletal System
                Bone
                Cartilage

                Uncategorized
                Uncategorized

                Comments

                Comment on this article