Biomechanical Testing of Commercially Available Soft-Tissue Augmentation Materials

Purpose

To evaluate several physical properties and physical dimensions of commercially available soft-tissue augmentation devices.

Methods

After 2 × 5–cm strips of several graft materials were hydrated, load elongation, cyclic and permanent displacement, percent elastic displacement, tensile modulus, stiffness, and ultimate load-to-failure strength were determined. With a 5-N preload, 30 cyclic loads between 5 N and 50 N were applied at 12.5 mm/s followed by destructive testing. A vertical stitch suture retention test was also performed.

Results

SportMesh (Biomet Sports Medicine, Warsaw, IN) displaced more than any other material (P < .001). GraftJacket MaxForce Extreme (Wright Medical Technology, Arlington, TN) and Allopatch HD 2 (Musculoskeletal Tissue Foundation, Edison, NJ) displaced more than RC Allograft (Arthrex, Naples, FL) (P < .05). Percent elastic deformation did not differ among these materials. OrthAdapt (Pegasus Biologics, Irvine CA) had a higher tensile modulus than RC Allograft, SportMesh, and Allopatch HD 2 (P < .001). Allopatch HD 1 and GraftJacket MaxForce Extreme had a higher tensile modulus than RC Allograft and SportMesh. GraftJacket MaxForce had a higher tensile modulus than RC Allograft (P < .001). GraftJacket MaxForce Extreme stiffness was greater than that of OrthAdapt and SportMesh (P < .001), and GraftJacket MaxForce, RC Allograft, Allopatch HD 1, and Allopatch HD 2 stiffness was greater than that of SportMesh (P < .001). The ultimate strength of GraftJacket MaxForce, GraftJacket MaxForce Extreme, Allopatch HD 1, and Allopatch HD 2 was greater than that of OrthAdapt and SportMesh (P < .05). Acellular human collagen matrix grafts (GraftJacket and Allopatch HD) showed greater suture retention strength than RC Allograft and SportMesh, which were both stronger than OrthAdapt (P < .05).

Conclusions

The acellular human collagen matrix grafts showed greater elongation than the cuff tendon allograft (RC Allograft), although SportMesh elongated more than all other materials tested. The tensile modulus, which is “normalized” to eliminate differences in the size of the tissue tested, was greater for the OrthAdapt material than for GraftJacket, Allopatch, RC Allograft, and SportMesh. Suture retention strength was greatest in the acellular human collagen matrix grafts (GraftJacket and Allopatch), whereas both SportMesh and RC Allograft had greater suture retention strength than OrthAdapt.

Clinical Relevance

Acellular human collagen matrix grafts (GraftJacket and Allopatch) are stronger after cyclic loading than SportMesh and OrthAdapt and show greater stiffness.

Key Words: Scaffold, Tendon graft, Biomechanical test, GraftJacket, OrthAdapt, SportMesh