BACKGROUND: The pathogenesis of tendon overuse injuries is poorly understood. The histopathology underlying tendinopathy at various anatomical locations is similar and may reflect a common pathologic process. HYPOTHESIS: Apoptosis contributes to the pathophysiology in patellar tendinopathy. STUDY DESIGN: Case control study; Level of evidence, 3. METHODS: We compared biopsy specimens from the patellar tendon in patients with patellar tendinopathy diagnosed clinically and with typical magnetic resonance image findings with biopsy specimens from a control group without any previous or current knee complaints to suggest patellar tendinopathy. The presence of apoptosis was examined with immunohistochemical methods using a polyclonal antibody recognizing active caspase-3, confirmed by labeling DNA strand breaks (F7-26 antibody) and nuclear morphology (fragmentation and condensation). RESULTS: The number of apoptotic cells per unit area (4.5 mm(2)) was 0.91 +/- 0.81 (SD) in tendinopathic samples and 0.21 +/- 0.21 in controls (P = .026). Although the tendinopathic samples displayed increased cellularity (average 162.5 nuclei/mm(2) vs 98.9 nuclei/mm(2)), the apoptotic index was higher (0.42% vs 0.17%, P = .014). CONCLUSION: Increased apoptotic cell death is a feature of patellar tendinosis. The role of apoptosis within the broader framework and time course of tendon overuse injury remains to be established.
BACKGROUND: The pathogenesis of tendon overuse injuries is poorly understood. The histopathology underlying tendinopathy at various anatomical locations is similar and may reflect a common pathologic process. HYPOTHESIS: Apoptosis contributes to the pathophysiology in patellar tendinopathy. STUDY DESIGN: Case control study; Level of evidence, 3. METHODS: We compared biopsy specimens from the patellar tendon in patients with patellar tendinopathy diagnosed clinically and with typical magnetic resonance image findings with biopsy specimens from a control group without any previous or current knee complaints to suggest patellar tendinopathy. The presence of apoptosis was examined with immunohistochemical methods using a polyclonal antibody recognizing active caspase-3, confirmed by labeling DNA strand breaks (F7-26 antibody) and nuclear morphology (fragmentation and condensation). RESULTS: The number of apoptotic cells per unit area (4.5 mm(2)) was 0.91 +/- 0.81 (SD) in tendinopathic samples and 0.21 +/- 0.21 in controls (P = .026). Although the tendinopathic samples displayed increased cellularity (average 162.5 nuclei/mm(2) vs 98.9 nuclei/mm(2)), the apoptotic index was higher (0.42% vs 0.17%, P = .014). CONCLUSION: Increased apoptotic cell death is a feature of patellar tendinosis. The role of apoptosis within the broader framework and time course of tendon overuse injury remains to be established.
Authors: Rafael Duarte Silva; Mark Anthony Glazebrook; Vinicius Castro Campos; Anilton Cesar Vasconcelos Journal: Int J Clin Exp Pathol Date: 2011-10-12
Authors: Steven P Arnoczky; Michael Lavagnino; Monika Egerbacher; Oscar Caballero; Keri Gardner; Marisa A Shender Journal: Clin Orthop Relat Res Date: 2008-05-06 Impact factor: 4.176
Authors: Neal L Millar; Ai Q Wei; Timothy J Molloy; Fiona Bonar; George A C Murrell Journal: Clin Orthop Relat Res Date: 2008-05-06 Impact factor: 4.176
Authors: Monika Egerbacher; Steven P Arnoczky; Oscar Caballero; Michael Lavagnino; Keri L Gardner Journal: Clin Orthop Relat Res Date: 2008-05-06 Impact factor: 4.176