A Pre-Clinical Test Platform for the Functional Evaluation of Scaffolds for Musculoskeletal Defects: The Meniscus

Suzanne Maher, PhD
Assistant Scientist, Research Division, Hospital for Special Surgery
Assistant Professor of Applied Biomechanics in Orthopaedic Surgery, Department of Orthopaedics, Weill Medical College of Cornell University


Scott A. Rodeo, MD
Attending Orthopaedic Surgeon, Hospital for Special Surgery
Professor of Orthopaedic Surgery, Weill Cornell Medical College


Hollis G. Potter, MD
Chief, Division of Magnetic Resonance Imaging
Attending Radiologist, Hospital for Special Surgery
Professor of Radiology, Weill College of Medicine of Cornell University


Lawrence J. Bonassar, PhD
Hospital for Special Surgery


Timothy Wright, PhD

Senior Scientist, Hospital for Special Surgery
F.M. Kirby Chair, Orthopaedic Biomechanics

Russell F. Warren, MD

Attending Orthopaedic Surgeon, Hospital for Special Surgery
Professor of Orthopaedic Surgery, Weill Cornell Medical College

Abstract

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.

This article appears in HSS Journal: Volume 7, Number 2.
View the full article at springerlink.com.

About the HSS Journal
HSS Journal, an academic peer-reviewed journal, is published twice a year, February and September, and features articles by internal faculty and HSS alumni that present current research and clinical work in the field of musculoskeletal medicine performed at HSS, including research articles, surgical procedures, and case reports.


^ Back to Top
Request an Appointment