A MECHANICAL COMPARISON OF GLUTEUS MEDIUS ATTACHMENT METHODS IN A CANINE MODEL

Seven techniques of gluteus medius attachment were compared in vitro i n a canine model. Four methods were used for tendon to tendon attachme nt: (a) two modified Bunnell-Mayer sutures, (b) two Kessler locking lo op sutures, (c) two horizontal mattress sutures, and (d) two sutures w ith a looped suture technique. The two methods of tendon to bone attac hment were repair with a 1 cm spiked staple and repair with a spiked w asher and screw, and the method of bone to bone attachment involved tw o figure-eight cerclage wires. The contralateral limb served as a cont rol. Compared with the bone to bone attachment, the four tendon to ten don attachments and the two tendon to bone attachments had significant ly less strength (31 and 30% of the ultimate load for bone to bone rep air, respectively) and tensile stiffness (24 and 39% of the tensile st iffness for bone to bone attachment, respectively) (p < 0.0001). The c ontrol specimens were significantly stronger and stiffer than all spec imens (p < 0.05) except those that had bone to bone fixation. There we re no significant differences among the four tendon to tendon suture r epairs with regard to either strength or stiffness; the values ranged from 28-45% of those of the controls. Among the tendon to bone repairs , fixation with a spiked washer and screw was significantly stronger t han that with a spiked staple (p = 0.032), but there was no difference between these two techniques with regard to stiffness.