An artificial tendon to connect the quadriceps muscle to the tibia

No permanent, reliable artificial tendon exists clinically. Our group developed the OrthoCoupler™ device as a versatile connector, fixed at one end to a muscle, and adaptable at the other end to inert implants such as prosthetic bones or to bone anchors. The objective of this study was to evaluate four configurations of the device to replace the extensor mechanism of the knee in goats. Within muscle, the four groups had: (A) needle-drawn uncoated bundles, (B) needle-drawn coated bundles, (C) barbed uncoated bundles, and (D) barbed coated bundles. The quadriceps tendon, patella, and patellar tendon were removed from the right hind limb in 24 goats. The four groups (n = 6 for each) were randomly assigned to connect the quadriceps muscle to the tibia (with a bone plate). Specimens were collected from each operated leg and contralateral unoperated controls both for mechanical testing and histology at 90 days post-surgery. In strength testing, maximum forces in the operated leg (vs. unoperated control) were 1,288 ± 123 N (vs. 1,387 ± 118 N) for group A, 1,323 ± 144 N (vs. 1,396 ± 779 N) for group B, 930 ± 125 N (vs. 1,337 ± 126 N) for group C, and 968 ± 109 N (vs. 1,528 ± 146 N) for group D (mean ± SEM). The strengths of the OrthoCoupler™ legs in the needled device groups were equivalent to unoperated controls (p = 0.6), while both barbed device groups had maximum forces significantly lower than their controls (p = 0.001). We believe this technology will yield improved procedures for clinical challenges in orthopaedic oncology, revision arthroplasty, tendon transfer, and tendon injury reconstruction.