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Impact insertion of osteochondral grafts: Interference fit and central graft reduction affect biomechanics and cartilage damage
Author(s) -
Su Alvin W.,
Chen Yunchan,
Wailes Dustin H.,
Wong Van W.,
Cai Shengqiang,
Chen Albert C.,
Bugbee William D.,
Sah Robert L.
Publication year - 2018
Publication title -
journal of orthopaedic research®
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.041
H-Index - 155
eISSN - 1554-527X
pISSN - 0736-0266
DOI - 10.1002/jor.23645
Subject(s) - biomechanics , reduction (mathematics) , cartilage , interference (communication) , interference fit , cartilage damage , affect (linguistics) , biomedical engineering , medicine , orthodontics , materials science , articular cartilage , anatomy , engineering , osteoarthritis , composite material , psychology , pathology , telecommunications , mathematics , geometry , channel (broadcasting) , alternative medicine , communication
An osteochondral graft (OCG) is an effective treatment for articular cartilage and osteochondral defects. Impact of an OCG during insertion into the osteochondral recipient site (OCR) can cause chondrocyte death and matrix damage. The aim of the present study was to analyze the effects of graft‐host interference fit and a modified OCG geometry on OCG insertion biomechanics and cartilage damage. The effects of interference fit (radius of OCG ‐ radius of OCR), loose (0.00 mm), moderate (0.05 mm), tight (0.10 mm), and of a tight fit with OCG geometry modification (central region of decreased radius), were analyzed for OCG cylinders and OCR blocks from adult bovine knee joints with an instrumented drop tower apparatus. An increasingly tight (OCG ‐ OCR) interference fit led to increased taps for insertion, peak axial force, graft cartilage axial compression, cumulative and total energy delivery to cartilage, lower time of peak axial force, lesser graft advancement during each tap, higher total crack length in the cartilage surface, and lower chondrocyte viability. The modified OCG, with reduction of diameter in the central area, altered the biomechanical insertion variables and biological consequences to be similar to those of the moderate interference fit scenario. Micro‐computed tomography confirmed structural interference between the OCR bone and both the proximal and distal bone segments of the OCGs, with the central regions being slightly separated for the modified OCGs. These results clarify OCG insertion biomechanics and mechanobiology, and introduce a simple modification of OCGs that facilitates insertion with reduced energy while maintaining a structural interference fit. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:377–386, 2018.