A Closer Look At Orthobiologics For Tendon Repair

Michael Troiano, DPM, and Harold Schoenhaus, DPM, FACFAS

   The surgeon proceeds to use the suture of choice (generally a long absorbing or non-absorbing braided suture) to tubularize the tendon in order to facilitate a strong and anatomically sized construct. Finally, wrap the Restore around the tendon and sew it upon itself to augment the repair and cover the sutures. Then rotate the Restore on its long axis so the sutures that hold the Restore in place are facing inward. Once this is in place, suture the Restore to the tendon with one stitch proximally and one stitch distally. When it comes to subsequent repair of the flexor retinaculum, one can usually use a high gauge vicryl.

Preserving Gliding Mechanisms For Tendons

   Another excellent use for Restore is when simple gliding mechanisms for a tendon are violated. One patient underwent an implant arthroplasty of the great toe joint. Unfortunately, the patient was non-adherent with early range of motion and, as a result, the extensor tendon became bound down to the overlying skin and the toe maintained an elevated posture.

   The surgeon subsequently performed a tenolysis. However, intraoperatively, there was a concern that the tendon would scar back to the overlying subcutaneous tissue and a similar result would occur. Therefore, the surgeon used Restore to delicately preserve the gliding of the extensor hallucis longus tendon sheath.

Pertinent Insights On Using GraftJacket

   When it comes to more extensive intrasubstance tears and complete ruptures, our orthobiologic of choice is GraftJacket, an acellular dermal matrix derived from human cadaveric skin. It undergoes a proprietary process that renders it totally unrecognizable by the body’s immune system. It consists of collagen and extracellular protein matrices. Revascularization is possible due to the scaffold, which is composed of elastin, collagen, proteoglycans and preserved blood vessel channels.

   The regenerative nature of GraftJacket allows it to “disappear” into the host tissues over time instead of leaving a foreign graft in the body. Histologically, GraftJacket is indistinguishable from surrounding host tissues. Simply stated, the product assumes the characteristics of the tissue to which it adheres. The product comes in various sizes and thicknesses. Therefore, one can select a different size based on the strength needed for the repair and the size of the defect the surgeon is repairing.

   Also bear in mind that GraftJacket is double-sided so one can place the “non-biologic side” or “gliding” side away from the repair. This will facilitate and preserve gliding of the tendon against the retinaculum or overlying subcutaneous tissues.

   GraftJacket has proven to be an integral part of the podiatric surgeon’s armamentarium in wound repair, ligament repair and fat pad restoration. Recently, there have been significant advances in using GraftJacket for tendon repair/augmentation and cartilage resurfacing.

   Although the entire technique of cartilage resurfacing is beyond the scope of this article, it is important to note that in certain instances, such as first metatarsophalangeal joint (MPJ) resurfacing, GraftJacket offers an excellent means of restoring the gliding motion of the flexor hallucis brevis/sesamoid complex. In the process of using GraftJacket for first MPJ cartilage resurfacing, one of the paramount events is histologic evidence of chondrocytes evident in first metatarsal biopsy. However, equally as important is the gliding mechanism of the sesamoidal flexor hallucis brevis tendon amalgamation.

   The biggest fault in the pathomechanics of hallux limitus/rigidus is when the flexor tendon and sesamoids bind to the first metatarsal. When performing a first metatarsal resurfacing, one uses a McGlamry elevator to separate the bound sesamoids from the first metatarsal. Unfortunately, due to denuded cartilage on the sesamoids and the first metatarsal, the sesamoids will rebind to the metatarsal in a few short weeks. However, interposing GraftJacket into this complex with the non-biologic side against the sesamoid-flexor apparatus preserves the gliding mechanism and also preserves the motion of the sesamoids under the first metatarsal.

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