Gluteus Medius Repair With Double-Row Fixation

Portal placement for the peritrochanteric space is performed as previously described (Video 1, Table 1).^,  A viewing portal for the 30° arthroscope is placed at the posterior margin of the vastus lateralis ridge. A large-diameter working cannula is established just distal to the ridge, and anchors are then placed from an entry site just proximal (Fig 1). Double-row fixation is best suited for large full-thickness lesions.

The bony footprint of the repair site, typically including the anterior trochanteric facet and part of the lateral trochanteric facet, is lightly prepared with a bur to provide a fresh surface, potentiating healing of the restored tendon. The tendon is mobilized and cleared of adhesions on its deep and superficial surfaces (Fig 2).

Proximal fixation is accomplished with 2 to 3 transverse or horizontally oriented double-loaded Healicoil anchors (Smith & Nephew, Andover, MA). The most anterior anchor is placed first (Fig 3). The site is tapped and the anchor screwed into place. It advances easily with only a 2-finger touch on the inserter. Because of the anchor's cylindrical design, its depth can be adjusted without compromising its pullout strength. The Healicoil also does not rely on cortical purchase for fixation strength and thus can be recessed as far as necessary.

A tendon-penetrating device is used to pass the sutures in a mattress fashion through the proximal portion of the tendon. Once passed, the sutures can then be retrieved through an anterior portal site and docked out of the way during subsequent suture management. One or two more Healicoil anchors are then placed from anterior to posterior, as needed, to provide broad-based coverage of the damaged tendon (Fig 4).

Once all sutures have been passed, each pair is tied, beginning from posterior to anterior. With each knot, 1 suture limb is retained to be incorporated into the distal fixation (Fig 5).

After one ensures the structural integrity of the proximal row, attention is then turned to the distal row. Fixation is achieved with a 4.5- or 5.5-mm Footprint anchor (Smith & Nephew). One Footprint anchor is used per Healicoil anchor. The awl is used to prepare the bone. The pair of suture limbs, 1 from each knot accompanying the doubly loaded Healicoil anchor, is withdrawn through the proximal cannula that will serve for introduction of the Footprint anchor. A lead loop through the Footprint serves to pull the suture limbs into the anchor. Slight tension is held on the suture limbs as the anchor is then passed through the cannula to the previously prepared site. The Footprint is aligned so that the sutures enter the footprint proximally in alignment with the paired Healicoil (Fig 6). The Footprint is then driven into place. At this point, the sutures still pass freely. They are individually tensioned to provide optimal approximation of the tendon to bone, avoiding excessive tension and strangulation. As the selected tension is titrated, the suture is then cleated to the inserter. Once both sutures have been satisfactorily tensioned, they are locked by tightening the knob on the Footprint anchor inserter. After 3 clicks, the knob is then loosened a few turns. The sutures are uncleated and inserter removed. The free suture ends are then cut flush with the bone. This process is repeated from anterior to posterior with 1 Footprint per Healicoil anchor.

Double-row fixation has particular appeal for repair of substantial tears of the gluteus medius because of the practical challenges of protecting the repair in a weight-bearing limb. The Healicoil and Footprint anchors provide a well-matched pair for accomplishing secure fixation. As mentioned, the Healicoil does not rely on cortical purchase for fixation and, with its cylindrical design, the depth can be adjusted into bone without compromising its pullout strength. The hollow core and fenestrations leave a minimal amount of material in the bone, and animal models have shown bony ingrowth. As the anchor is seated, we routinely observe marrow products exuding through its center, thus appearing to provide a direct conduit for these marrow products to the repair site and an enhanced biological healing environment. The footprint is a knotless device that allows the sutures from the proximal Healicoil fixation to be incorporated into a double-row repair. When the Footprint is seated in bone, the sutures can still be adjusted for more or less tension, allowing adjustment to the desired amount necessary for optimal tendon approximation.

After completion of the repair, the integrity is carefully assessed because this influences the rehabilitation strategy for optimizing the functional outcome (Fig 7). Protected weight bearing may be necessary for 6 to 8 weeks, with some precautions for 4 months during the healing period.

The principal advantage of the described technique is optimizing the security of soft-tissue fixation to bone, which is usually the weak link in a tendon repair construct. Although we have not observed any problems with this method, 1 potential concern might be if the Footprint were overstuffed with anchors, creating a potential stress riser and introducing the possibility of a spontaneous fracture of the greater trochanter. It is also likely that there are some massive abductor deficits, not amenable to arthroscopic repair, that may require more extensive tissue transfer.