Article Text

Download PDFPDF

Increased mast cell numbers in human patellar tendinosis: correlation with symptom duration and vascular hyperplasia
  1. A Scott1,6,
  2. Ø Lian2,3,
  3. R Bahr3,6,
  4. D A Hart4,
  5. V Duronio1,
  6. K M Khan1,5,6
  1. 1
    Department of Medicine, University of British Columbia, Vancouver, Canada
  2. 2
    Kristiansund Hospital, Kristiansund, Norway
  3. 3
    Oslo Sport Trauma Research Center, Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway
  4. 4
    McCaig Center for Joint Injury and Arthritis Research, Faculty of Medicine, University of Calgary
  5. 5
    Department of Family Practice, University of British Columbia, Vancouver, Canada
  6. 6
    Centre for Hip Health, Vancouver Coastal Health Research Institute, Vancouver, Canada
  1. Dr K Khan, Department of Family Practice, University of British Columbia, 320 - 5950 University Blvd, Vancouver, Canada V6T 1Z3; kkhan{at}


Objectives: The cellular basis of painful tendon overuse pathology (tendinosis) is poorly understood. It has been suggested that because of the close anatomical associations between mast cells and vessels in connective tissues, mast cells may mediate the development of tendon hypervascularity or oedema.

Objectives: To examine the distribution of mast cells in men and women with patellar tendinopathy.

Design: Case–control study.

Methods: Tendinopathic tissue was collected at open debridement of the patellar tendon and a control tendon from patients undergoing intramedullary nailing of the tibia. The tendon was assessed immunohistochemically by evaluating the distribution of mast cells (AA1), and markers for T lymphocytes (CD3) and macrophages (CD68). The vessel-area fraction was quantified using computer-assisted digital image analysis.

Results: The prevalence of mast cells per mm2 (mean 3.3 (SD 3.0)) was greater in tendinosis tissue than in controls (1.1 (1.5); p = 0.036). In patients with tendinosis, mast cell density was moderately correlated with the vessel-area fraction (r2 = 0.49) and with symptom duration (r2 = 0.52).

Conclusion: Mast-cell prevalence in patellar tendinopathy was increased and was predominantly associated with vascular hyperplasia, particularly in patients with longstanding symptoms. Future research should investigate whether mast cells play direct or indirect modulatory roles in the development and progression of human tendinosis.

View Full Text

Statistics from


  • Competing interests: None.

  • Funding: This work was funded by grants from the Canadian Institutes of Health Research (CIHR) (grant MOP-77551) and the Worker’s Compensation Board of British Columbia (grant RS0203-DG-13). The Oslo Sports Trauma Research Center has been established at the Norwegian University of Sport and Physical Education through generous grants from the Royal Norwegian Ministry of Culture, the Norwegian Olympic Committee and Confederation of Sport, Norsk Tipping, and Pfizer. The funding agents played no role in study design or manuscript preparation. AS is a recipient of a CIHR Post-Doctoral Fellowship. DAH is the Calgary Foundation-Grace Glaum Professor in Arthritis Research and supported by the Institute of Gender and Health of CIHR. VD is a recipient of a Michael Smith Foundation for Health Research Senior Scholar Award. KMK is a recipient of a CIHR New Investigator Award.

  • Ethics approval: Ethics approval was obtained from the university and hospital ethics committees.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Linked Articles