Use of a Magnesium-Based Bone Adhesive for Flexor Tendon-to-Bone Healing

Abstract

Purpose Our previous studies in a canine animal model demonstrated that the flexor tendon-to-bone insertion site has a poor capacity to heal. Magnesium based adhesives have the potential to improve tendon-to-bone healing. Therefore, we hypothesized that magnesium based bone adhesive (MBA) will improve the tendon-to-bone biomechanical properties initially and in the early period after repair. Methods Flexor digitorum profundus tendons were injured and repaired into bone tunnels in the distal phalanges of dogs. The bone tunnels were either filled with MBA prior to completing the repair or left empty (CTL). Histologic appearance, tensile properties, range of motion, and bone density were examined at time zero and 21 days after the repair. Results There was no histologic evidence of acute inflammation. There appeared to be more mast cells in the MBA group than in the CTL group. Chronic inflammatory infiltrate and fibrosis was slightly higher in the MBA group compared to the CTL group. Tensile properties at time zero were significantly higher in the MBA group compared to the CTL group. However, tensile properties were significantly lower in the MBA group compared to the CTL group at 21 days. Range of motion and bone density were significantly lower in the MBA and CTL groups compared to normal (i.e., uninjured) at 21 days; no differences were seen when comparing MBA to CTL. Conclusions We found that the initial biomechanical properties of flexor tendon-to-bone repairs can be improved with MBA. However, MBA use in vivo led to a decrease in the biomechanical properties of the repair. There was no effect of MBA on bone density or range of motion in the early period after repair. Our histologic analysis suggests that the poor healing in the MBA group may have been due to an allergic response or to increased chronic inflammation due to the foreign material.

The Rotator Cuff Organ: Integrating Developmental Biology, Tissue Engineering, and Surgical Considerations to Treat Chronic Massive Rotator Cuff Tears

“…160 While neutralization of TGF-b signaling compromised healing, neither isoform preferential enhanced the mechanical properties of the repair when applied exogenously through an osmotic pump. 160 Overall, augmentation of the healing insertion site with growth factors, 161,162 bone adhesives, 163,164 or anti-inflammatory agents, [165][166][167] has yielded equivocal results; structural changes, based upon histology, do not consistently correspond to changes in mechanical properties. These findings are reviewed in greater detail elsewhere.…”

Enhanced tendon-to-bone repair through adhesive films

“…Idealized tendon-tendon and tendon-bone plank repairs were tested similar to previously described protocols for testing flexor tendons [25, 26, 27, 28]. After 5 cycles of triangular-ramp preconditioning to 1 mm displacement, samples were pulled in uniaxial tension using a material testing machine (5866; Instron Corp., Norwood, MA, chosen because of a high capacity load cell) at 0.3 mm/s until failure.…”

Shear lag sutures: Improved suture repair through the use of adhesives

“…Clinical repairs of cadaveric flexor digitorum profundus tendons were tested as described previously [41, 42, 43, 36]. After preconditioning, samples were pulled in uniaxial tension using a material testing machine (5866; Instron Corp., Norwood, MA, chosen because of a high capacity load cell) at 0.3 mm/s until failure.…”