A Pre-Clinical Test Platform for the Functional Evaluation of Scaffolds for Musculoskeletal Defects: The Meniscus
- 310 Downloads
In an attempt to delay the progression of osteoarthritis from an index injury, early intervention via repair of injured musculoskeletal soft tissue has been advocated. Despite the development of a number of scaffolds intended to treat soft tissue defects, information about their functional performance is lacking. The goal of this study was to consolidate a suite of in vitro and in vivo models into a pre-clinical test platform to assess the functional performance of meniscal repair scaffolds. Our objective was to assess the ability of a scaffold (Actifit™; Orteq, UK) to carry load without detrimentally abrading against articular cartilage. Three test modules were used to assess the functional performance of meniscal repair scaffolds. The first module tested the ability of the scaffold to carry load in an in vitro model designed to measure the change in normal contact stress magnitude on the tibial plateau of cadaveric knees after scaffold implantation. The second module assessed the in vitro frictional coefficient of the scaffold against cartilage to assess the likelihood that the scaffold would destructively abrade against articular cartilage in vivo. The third module consisted of an assessment of functional performance in vivo by measuring the structure and composition of articular cartilage across the tibial plateau 12 months after scaffold implantation in an ovine model. In vitro, the scaffold improved contact mechanics relative to a partly meniscectomized knee suggesting that, in vivo, less damage would be seen in the scaffold implanted knees vs. partly meniscectomized knees. However, there was no significant difference in the condition of articular cartilage between the two groups. Moreover, in spite of the high coefficient of friction between the scaffold and articular cartilage, there was no significant damage in the articular cartilage underneath the scaffold. The discrepancy between the in vitro and in vivo models was likely influenced by the abundant tissue generated within the scaffold and the unexpected tissue that regenerated within the site of the partial meniscectomy. We are currently augmenting our suite of tests so that we can pre-clinically evaluate the functional performance at time zero and as a function of time after implantation.
Keywordsmeniscus scaffold knee cartilage
This study was funded by Orteq Sports Medicine Ltd., London, UK. The research was conducted in a facility constructed with support from Research Facilities Improvement Program Grant Number C06-RR12538-01 from the National Center for Research Resources, NIH.
- 3.Arnoczky SP, Cook JL, Carter T, Turner S. Translational Models for Studying Meniscal Repair and Replacement: What they can and cannot tell us.Tissue Eng Part B Rev. 2009 Aug 21. (Epub ahead of print)Google Scholar
- 8.Chevrier A, Nelea M, Hurtig MB, Hoemann CD, Buschmann MD.Meniscus structure in human, sheep, and rabbit for animal models of meniscus repair. J Orthop Res. 2009 Feb 25 (Epub ahead of print)Google Scholar
- 14.Heinlein B, Kutzner I, Graichen F, Bender A, Rohlmann A, Halder AM, Beier A, Bergmann G (2009) ESB Clinical Biomechanics Award 2008: Complete data of total knee replacement loading for level walking and stair climbing measured in vivo with a follow-up of 6–10 months. Clin Biomech (Bristol, Avon) 24(4): 315–26. Epub 2009 Mar 13.CrossRefGoogle Scholar
- 15.Hofmann AA, Heithoff SM, Camargo M. Cementless total knee arthroplasty in patients 50 years or younger. Clin Orthop Relat Res. 2002 Nov;(404):102–107.Google Scholar
- 24.Maher SA, Rodeo SA, Doty SB, Brophy R, Potter H, Foo LF, Rosenblatt L, Deng XH, Turner AS, Wright TM, Warren RF. Evaluation of a porous polyurethane scaffold in a partial meniscal defect ovine model. Arthroscopy. 2010 Nov;26(11):1510–9. Epub 2010 Sep 19.Google Scholar