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Transtibial pullout suture (TPS) repair of posterior medial meniscus root (PMMR) tears was shown to achieve good clinical outcomes. The purpose of this study was to compare biomechanically, a novel technique designed to repair PMMR tears using tendon graft (TG) and conventional TPS repair. Twelve porcine tibiae (n = 6 each) TG group: flexor digitorum profundus tendon was passed through an incision in the root area, created 5 mm postero-medially along the edge of the attachment area. TPS group: a modified Mason-Allen suture was created using no. 2 FiberWire. The tendon grafts and sutures were threaded through the bone tunnel and then fixed to the anterolateral cortex of the tibia. The two groups underwent cyclic loading followed by a load-to-failure test. Displacements of the constructs after 100, 500, and 1000 loading cycles, and the maximum load, stiffness, and elongation at failure were recorded. The TG technique had significantly lower elongation and higher stiffness compared with the TPS. The maximum load of the TG group was significantly lower than that of the TPS group. Failure modes for all specimens were caused by the suture or graft cutting through the meniscus. Lesser elongation and higher stiffness of the constructs in TG technique over those in the standard TPS technique might be beneficial for postoperative biological healing between the meniscus and tibial plateau. However, a slower rehabilitation program might be necessary due to its relatively lower maximum failure load.

Spinal interbody fusion is the most common surgery for treatment of disk degeneration, but the increased stress on adjacent level has been noted. Disk replacement has become an alternative strategy for dealing with problem of disk degeneration. Compressibility of an intact intervertebral disk is contributive to protect spinal structure, but certain mechanism has seldom been preserved in most of the commercial products of ball-and-socket-styled artificial disks. A novel compressible artificial disk design for cervical spine has been developed and compared the biomechanical behaviors with intact and incompressible models by finite element method. Physiological loadings have been applied for evaluating the biomechanical performances in different implant designs. Compressible mechanism represented a similar kinematic behavior to intact cervical spine model. Greater mobility and larger facet joint contact force were observed in incompressible disk model. Biomechanical performances of cervical artificial disk with compressible mechanism may be better reproduced to those of intact cervical spine under physiological loadings. With adequate assigned structural stiffness of the compressible mechanism in the artificial disk, the concept is worth considering for further cervical artificial disk designs.