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VEGF Expression in Patellar Tendinopathy: A Preliminary Study


Vascular function and angiogenesis are regulated by vascular endothelial growth factor-A (VEGF). The purpose of this preliminary study was to address the following questions: Is VEGF expression in the patellar tendon more prevalent in patients with patellar tendinopathy than in individuals with normal, pain-free patellar tendons? Which cell populations express VEGF in normal and tendinopathic tendon? Is there a difference in symptom duration between VEGF+ and VEGF− tendons? We collected patellar tendon tissue from 22 patients undergoing open débridement of the patellar tendon and from 10 patients undergoing intramedullary nailing of the tibia. VEGF expression was assessed immunohistochemically. Relevant inflammatory and repair cell types were immunolabeled. VEGF expression was absent from control tendons, but was present in a subset of patients with histopathological evidence of angiofibroblastic tendinosis. VEGF was expressed in the intimal layer of tendon vessels, but was absent in other cell types. Patients demonstrating VEGF expression in the patellar tendon had a shorter symptom duration (12 ± 7.8 months) than patients with no detectable VEGF (32.8 ± 23.5 months). VEGF may contribute to the vascular hyperplasia that is a cardinal feature of symptomatic tendinosis, particularly in cases with more recent onset.

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We thank the Oslo Sports Trauma Research Center 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. We thank Rafat Sobouti for assistance viewing tissue sections.

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Corresponding author

Correspondence to Alexander Scott MSc, BSc(PT).

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Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.

One of more of the authors received funding from the Canadian Institutes of Health Research (AS, DAH, VD), the Worker’s Compensation Board of British Columbia (AS, VD), the Oslo Sports Trauma Research Center (OL, RB); one of the authors (AS) has received funding through a CIHR Post-Doctoral Fellowship; one of the authors (DAH) is the Calgary Foundation-Grace Glaum Professor in Arthritis Research and supported by IGH of CIHR; one of the authors (VD) receives funding through a Michael Smith Foundation for Health Research Senior Scholar fellowship.

Each author certifies that his or her institution has approved the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.

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Scott, A., Lian, Ø., Bahr, R. et al. VEGF Expression in Patellar Tendinopathy: A Preliminary Study. Clin Orthop Relat Res 466, 1598–1604 (2008).

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  • Patellar Tendon
  • Vascular Endothelial Growth Factor
  • Patellar Tendinopathy
  • Rupture Achilles Tendon
  • Mast Cell Density