Extended healing validation of an artificial tendon to connect the quadriceps muscle to the Tibia: 180‐day study

Abstract

Whenever a tendon or its bone insertion is disrupted or removed, existing surgical techniques provide a temporary connection or scaffolding to promote healing, but the interface of living to nonliving materials soon breaks down under the stress of these applications, if it must bear the load more than acutely. Patients are thus disabled whose prostheses, defect size, or mere anatomy limit the availability or outcomes of such treatments. Our group developed the OrthoCoupler™ device to join skeletal muscle to prosthetic or natural structures without this interface breakdown. In this study, the goat knee extensor mechanism (quadriceps tendon, patella, and patellar tendon) was removed from the right hind limb in 16 goats. The device connected the quadriceps muscle to a stainless steel bone plate on the tibia. Mechanical testing and histology specimens were collected from each operated leg and contra lateral unoperated control legs at 180 days. Maximum forces in the operated leg (vs. unoperated) were 1400± 93N (vs. 1179± 61 N), linear stiffnesses were 33± 3 N/mm (vs. 37 ± 4N/mm), and elongations at failure were 92.1 ± 5.3 mm (vs. 68.4 ± 3.8 mm; mean ± SEM). Higher maximum forces (p = 0.02) and elongations at failure (p = 0.008) of legs with the device versus unoperated controls were significant; linear stiffnesses were not (p = 0.3). We believe this technology will yield improved procedures for clinical challenges in orthopaedic oncology, revision arthroplasty, tendon transfer, and tendon injury reconstruction.

Replacement of tibialis cranialis tendon with polyester, silicone-coated artificial tendon preserves biomechanical function in rabbits

“…There were several limitations of our study. First, the number of samples per group was relatively small, which may have underpowered our statistical comparisons for some variables; however, the group size was similar to those of the previous in vivo studies of the PET-SI tendons [14][15][16][17] . Second, the study duration was relatively short; functional recovery may have been improved with more time.…”

“…The artificial tendon, adapted from a previously reported design [14][15][16][17] , consisted of two custom double-armed strands of size 0 braided polyester suture (RK Manufacturing, Danbury, CT, USA) (Figure 1). The strands were folded in half and braided for the desired length of the artificial tendon; tendons of varying lengths were fabricated in 2 to 4 mm increments to accommodate variation in lengths of the biological tendons they replaced.…”

“…Many types of artificial tendons of varying designs and materials have been tested [10][11][12][13] . One recent polyester, silicone-coated (PET-SI) artificial tendon was tested in rabbits 14 and goats [15][16][17] for up to 180 days; the artificial tendon integrated closely with the muscle fibers with no apparent scarring; the muscle-artificial tendon interface was stronger than the muscle itself. Similar artificial tendons have been used in humans 18,19 .…”

Repair of Tendon Disruption Using a Novel Synthetic Fiber Implant in Dogs and Cats: The Surgical Procedure and Three Case Reports

“…The one involving an interpositional bone plate grafting supplemented with the bone marrow onto a metallic prothesis has been tested successfully in big dog corpses (range: 26–33 kg) [ 29 ]. An implant sutured through multiple knot-tying showed excellent clinical results in goats [ 30 , 31 ]. The implant described in the present report may also be considered as an effective alternative solution, with the advantages of providing a simpler operating procedure and suiting a large range of animal sizes.…”

Implanted Passive Engineering Mechanism Improves Hand Function after Tendon Transfer Surgery: A Cadaver-Based Study

“…First, in addition to fabricating the device using biocompatible materials such as titanium or ultra high molecular weight polyethylene (UHMWPE), the mechanism may have to be chemically coated to reduce fibrosis when implanted in vivo long-term [30]. Second, the pulley-based procedure also depends on technology to make attachments between the biological tendon and the mechanism's artificial components [17, 21, 28]. Third, the mechanism may have to be enclosed in a sheath of biocompatible material in order to reduce injury to surrounding tissue while the mechanism moves inside the forearm [9, 20].…”