PURPOSE: The pathogenesis of patellar tendinopathy remains unclear. Expression of BMP-2/-4/-7 was reported in an ossified failed tendon healing animal model of patellar tendinopathy. This study aimed to investigate the expression of these chondro-osteogenic BMPs in clinical samples of patellar tendinopathy. METHODS: Patellar tendon samples were collected from 16 consecutive patients with patellar tendinopathy and 16 consecutive controls undergoing anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft in the authors' hospital after getting their consent. The expression of BMP-2/-4/-7 was examined in all samples using immunohistochemistry. Ossification observed in two tendinopathy samples was characterized by histology, alizarin red S staining, alcian blue staining, TRAP staining and immunohistochemical staining of Sox9, osteopontin (OPN) and osteocalcin (OCN). RESULTS: Regions of hypo- and hyper-cellularity and vascularity, with loss of crimp structure of collagen matrix, were observed in patellar tendinopathy samples. Round cells and in some cases, cells with typical chondrocyte phenotype were observed. For the ossified tendinopathy samples with positive alizarin red S staining, OPN-positive and Sox9-positive chondrocyte-like cells in alcian blue-stained extracellular matrix, OCN-positive osteoblast-like cells and TRAP-positive multi-nucleated cells were observed around the ossified deposits. No expression of BMP-2/-4/-7 was observed in healthy patellar tendons. However, the expression of BMP-2/-4/-7 was observed in all patellar tendinopathy samples with or without ossification. CONCLUSIONS: Clinical samples of patellar tendinopathy showed ectopic expression of BMP-2/-4/-7. This was not evident in control samples from healthy patellar tendons. LEVEL OF EVIDENCE: Prognostic studies, Level III.
PURPOSE: The pathogenesis of patellar tendinopathy remains unclear. Expression of BMP-2/-4/-7 was reported in an ossified failed tendon healing animal model of patellar tendinopathy. This study aimed to investigate the expression of these chondro-osteogenic BMPs in clinical samples of patellar tendinopathy. METHODS: Patellar tendon samples were collected from 16 consecutive patients with patellar tendinopathy and 16 consecutive controls undergoing anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft in the authors' hospital after getting their consent. The expression of BMP-2/-4/-7 was examined in all samples using immunohistochemistry. Ossification observed in two tendinopathy samples was characterized by histology, alizarin red S staining, alcian blue staining, TRAP staining and immunohistochemical staining of Sox9, osteopontin (OPN) and osteocalcin (OCN). RESULTS: Regions of hypo- and hyper-cellularity and vascularity, with loss of crimp structure of collagen matrix, were observed in patellar tendinopathy samples. Round cells and in some cases, cells with typical chondrocyte phenotype were observed. For the ossified tendinopathy samples with positive alizarin red S staining, OPN-positive and Sox9-positive chondrocyte-like cells in alcian blue-stained extracellular matrix, OCN-positive osteoblast-like cells and TRAP-positive multi-nucleated cells were observed around the ossified deposits. No expression of BMP-2/-4/-7 was observed in healthy patellar tendons. However, the expression of BMP-2/-4/-7 was observed in all patellar tendinopathy samples with or without ossification. CONCLUSIONS:Clinical samples of patellar tendinopathy showed ectopic expression of BMP-2/-4/-7. This was not evident in control samples from healthy patellar tendons. LEVEL OF EVIDENCE: Prognostic studies, Level III.
Authors: K M Khan; F Bonar; P M Desmond; J L Cook; D A Young; P J Visentini; M W Fehrmann; Z S Kiss; P A O'Brien; P R Harcourt; R J Dowling; R M O'Sullivan; K J Crichton; B M Tress; J D Wark Journal: Radiology Date: 1996-09 Impact factor: 11.105
Authors: Pauline Po Yee Lui; Yin Mei Wong; Yun Feng Rui; Yuk Wa Lee; Lai Shan Chan; Kai Ming Chan Journal: J Orthop Res Date: 2010-12-23 Impact factor: 3.494
Authors: Sai Chuen Fu; Wen Wang; Hon Man Pau; Yim Ping Wong; Kai Ming Chan; Christer Gustav Rolf Journal: Clin Orthop Relat Res Date: 2002-07 Impact factor: 4.176
Authors: Lasse Lempainen; Kristian Johansson; Ingo J Banke; Juha Ranne; Keijo Mäkelä; Janne Sarimo; Pekka Niemi; Sakari Orava Journal: Muscles Ligaments Tendons J Date: 2015-03-27
Authors: Ingo Grafe; Stefanie Alexander; Jonathan R Peterson; Taylor Nicholas Snider; Benjamin Levi; Brendan Lee; Yuji Mishina Journal: Cold Spring Harb Perspect Biol Date: 2018-05-01 Impact factor: 10.005