GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • SAGE Publications  (4)
  • Kobayashi, Masahiko  (4)
Material
Publisher
  • SAGE Publications  (4)
Person/Organisation
Language
Years
  • 1
    Online Resource
    Online Resource
    Mechanical and Biochemical Effect of Monopolar Radiofrequency Energy on Human Articular Cartilage : An in Vitro Study
    SAGE Publications ; 2006
    In:  The American Journal of Sports Medicine Vol. 34, No. 8 ( 2006-08), p. 1322-1327
    Details
    In: The American Journal of Sports Medicine, SAGE Publications, Vol. 34, No. 8 ( 2006-08), p. 1322-1327
    Abstract: There are growing concerns about thermal chondroplasty using radiofrequency energy to treat partial-thickness cartilage defects. However, most studies emphasize effects on chondrocyte viability, and other factors such as mechanical properties are less studied. Hypothesis Radiofrequency energy may cause significant effects on articular cartilage other than chondrocyte viability. Study Design Controlled laboratory study. Methods Human osteoarthritic cartilage samples were obtained from total knee arthroplasty, and monopolar radiofrequency energy was applied using commercially available equipment. Material properties (compressive stiffness, surface roughness, and thickness) just before and after thermal treatment were determined using ultrasound. A series of biochemical analyses were also performed after explant culture of the samples. Results The cartilage surface became smoother by radiofrequency energy, whereas cartilage stiffness or thickness was not altered significantly. Collagen fibrils, especially in the superficial layers, were converted to denatured form, whereas proteoglycan contents released in the media as well as retained in the tissue remained unchanged. The concentrations of matrix metalloproteinases (MMP-1 and MMP-2) were reduced remarkably. Conclusion Radiofrequency energy is able to create a smooth cartilage surface and reduce catabolic enzymes at the cost of collagen denaturation and chondrocyte death in the superficial layers. The stiffness of the cartilage is not changed at time zero. Clinical Relevance Further animal as well as clinical studies will be necessary to fully evaluate the long-term effects of radiofrequency energy.
    Type of Medium: Online Resource
    ISSN: 0363-5465 , 1552-3365
    URL: Article
    DOI: 10.1177/0363546506287742
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2006
    detail.hit.zdb_id: 2063945-4
    SSG: 31
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Structural Damage and Chemical Contaminants on Reprocessed Arthroscopic Shaver Blades
    SAGE Publications ; 2009
    In:  The American Journal of Sports Medicine Vol. 37, No. 2 ( 2009-02), p. 266-273
    Details
    In: The American Journal of Sports Medicine, SAGE Publications, Vol. 37, No. 2 ( 2009-02), p. 266-273
    Abstract: In response to socioeconomic pressure to cut budgets in medicine, single-use surgical instruments are often reprocessed despite potential biological hazard. Purpose To evaluate the quality and contaminants of reprocessed shaver blades. Hypothesis Reprocessed shaver blades have mechanical damage and chemical contamination. Study Design Controlled laboratory study. Methods Seven blades and 3 abraders were reprocessed 1 time or 3 times and then were assessed. In the first part of the study, structural damage on the blades after 3 reprocessings was compared to that after 1 reprocessing using optical microscopy. In the second part, surface damage was observed using optical microscopy and scanning electron microscopy; elemental and chemical analyses of contaminants found by the microscopy were performed using scanning electron microscopy/energy dispersive x-ray spectroscopy, scanning Auger microscopy, and Fourier transform infrared spectroscopy. Results Optical microscopic examination revealed abrasion on the surface of the inner blade and cracks on the inner tube after 1 reprocessing. These changes were more evident after 3 reprocessings. Scanning electron microscopy/energy dispersive x-ray spectroscopy of the inner cutter of the blade reprocessed once showed contaminants containing calcium, carbon, oxygen, and silicon, and Fourier transform infrared spectroscopy demonstrated biological protein consisting mainly of collagen, some type of salts, and polycarbonate used in plastic molding. Scanning electron microscopy/energy dispersive x-ray spectroscopy of the inner cutter of the reprocessed abrader revealed contaminants containing carbon, calcium, phosphorous, and oxygen, and Fourier transform infrared spectroscopy showed H2O, hydroxyapatite, and hydroxyl proteins. Scanning Auger microscopy showed that the tin-nickel plating on the moving blade and abrader was missing in some locations. Conclusion This is the first study to evaluate both mechanical damage and chemical contaminants containing collagen, hydroxyapatite, and salts on the reprocessed arthroscopic shaver blades. Clinical Relevance Surgeons should keep in mind that mechanical damage and chemical contamination are found on reprocessed arthroscopic blades.
    Type of Medium: Online Resource
    ISSN: 0363-5465 , 1552-3365
    URL: Article
    DOI: 10.1177/0363546508325668
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2009
    detail.hit.zdb_id: 2063945-4
    SSG: 31
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    Intraoperative Acoustic Evaluation of Living Human Cartilage of the Elbow and Knee during Mosaicplasty for Osteochondritis Dissecans of the Elbow : An in vivo Study
    SAGE Publications ; 2008
    In:  The American Journal of Sports Medicine Vol. 36, No. 12 ( 2008-12), p. 2345-2353
    Details
    In: The American Journal of Sports Medicine, SAGE Publications, Vol. 36, No. 12 ( 2008-12), p. 2345-2353
    Abstract: Autologous osteochondral mosaicplasty for osteochondritis dissecans of the capitellum is being used increasingly In adolescent patients. Little research has been published on the material properties of living human cartilage of the elbow and knee. Hypothesis The cartilage of the osteochondritis dissecans lesion is detected as degenerated by ultrasound. The material properties of the cartilage of the intact part of the elbow are not different from those of the intact knee except in thickness. Study Design Descriptive laboratory study. Methods The authors studied 10 young male athletes with osteochondritis dissecans of the capitellum who underwent mosaicplasty. An acoustic probe was used for measurement, and the wavelet transform method was used. Three parameters were used: signal intensity (Index of cartilage stiffness), signal duration (index of roughness), and signal interval (index of thickness). Results The cartilage of the osteochondritis dissecans lesion had lower signal intensity than did the intact part of the capitellum. The cartilage of the radial head opposite the capitellum had significantly lower signal intensity and higher signal duration than did other sites. The signal intensity of the radial head was significantly higher in early-stage patients than in late-stage Patients, although the macroscopic view was almost all intact. The signal intensity of the plug was decreased significantly after 9rafting. Conclusion The osteochondritis dissecans lesion had lower signal intensity than did the intact part of the capitellum. Although the macroscopic view looked intact, the radial head cartilage was degenerated as measured acoustically. Clinical Relevance Not only the cartilage of the capitellum but the cartilage of the radial head are acoustically degenerated in osteochondritis dissecans patients. Plugs might be damaged in the transplanting procedure, and further follow-up is necessary.
    Type of Medium: Online Resource
    ISSN: 0363-5465 , 1552-3365
    URL: Article
    DOI: 10.1177/0363546508322898
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2008
    detail.hit.zdb_id: 2063945-4
    SSG: 31
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Positive Effect of Alendronate on Subchondral Bone Healing and Subsequent Cartilage Repair in a Rabbit Osteochondral Defect Model
    SAGE Publications ; 2009
    In:  The American Journal of Sports Medicine Vol. 37, No. 1_suppl ( 2009-11), p. 139-147
    Details
    In: The American Journal of Sports Medicine, SAGE Publications, Vol. 37, No. 1_suppl ( 2009-11), p. 139-147
    Abstract: Cartilage and subchondral bone have recently been considered an osteochondral unit. The treatment of osteo-chondral lesions is still challenging, but better subchondral bone repair may result in higher quality repaired cartilage. Hypotheses Alendronate accelerates bone formation in osteochondral defects and affects the quality of the repaired cartilage. Study Design Controlled laboratory study. Methods Osteochondral defects were made on the left trochleas of 50 rabbits, which were assigned to 1 of 3 groups: control, ALN (weekly subcutaneous injection of 0.14 mg/mL alendronate), and ALN-S (alendronate injection in the first 8 weeks only). They were evaluated at 4, 8, 24, and 52 weeks. Bone repair was evaluated with microcomputed tomography and histologic evaluation. Cartilage repair was evaluated with ultrasound and histologic analyses. Results At 4 weeks, the defects were filled, and cartilage-like repair tissue was observed in the ALN group, whereas the defects were incompletely filled in the control group. Alendronate treatment enhanced early bone formation and mineralization in the osteochondral defect for the first 8 weeks. The continuous injection of alendronate for 24 weeks resulted in delayed bone remodeling, but the rabbits in the ALN-S group showed good integrity of the subchondral bone plate, without delayed remodeling. At 52 weeks, the ALN-S group had a columnar arrangement of chondrocytes that had less fibrillation and looked superior to those in the ALN and control groups. Ultrasound analysis showed better quality of repaired cartilage of the ALN and ALN-S group than the control group. Conclusion Alendronate accelerated bone formation without inhibiting its mineralization but thereafter inhibited bone remodeling in an osteochondral defect. The withdrawal of alendronate at 8 weeks avoided the delayed remodeling and showed better sub-chondral bone repair. At 52 weeks, better subchondral bone repair resulted in better cartilage quality. Clinical Relevance: Alendronate administered in the early period accelerates bone formation and improves the quality of the repaired cartilage.
    Type of Medium: Online Resource
    ISSN: 0363-5465 , 1552-3365
    URL: Article
    DOI: 10.1177/0363546509350984
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2009
    detail.hit.zdb_id: 2063945-4
    SSG: 31
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...