Soft Tissue to Bone Healing in Rotator Cuff Repair - Structural Interfaces and Attachments in Biology - page 257

Fig. 12.6 Anchors are placed into the greater tuberosity. The anchor is analogous to a small screw
with an eyelet through which sutures pass and is used to repair the tendon to bone. Anchors are
made from a variety of materials including metal, bioabsorbable, and nonabsorbable plastics.
The final repair of tendon to bone is shown on the right
The repair is performed with the arthroscope and working instruments in the
subacromial space, between the rotator cuff tendon and the acromial process of the
scapula. An anterolateral portal creates access for working instruments. A limited
bursectomy allows visualization of the retracted tendon and the greater tuberosity,
the insertion site for the supraspinatus tendon. The edge of the tendon is debrided
with a shaver. The bone of the tuberosity is likewise debrided, removing remnants
of tendon tissue and exposing punctate bleeding bone. The bone is not decorticated,
as this will compromise subsequent anchor fixation.
A description of a double row repair follows [ 54 ]. As mentioned previously,
multiple methods of tendon-to-bone reattachment are possible; however, the basic
principles are the same. The tendon is mobilized from surrounding adhesions to
reduce tension on the repair. The tendon is then attached to the bone. The attach-
ment should be secure, minimize motion at the tendon bone interface, and maxi-
mize contact area at the tendon bone interface, yet not strangulate the tissue [ 41 , 43 ,
44 , 46 , 47 , 55 ]. The repair configuration should not be so tight that blood flow is
compromised. This may result in a tendon tear subsequent to mechanical attenua-
tion at the suture-tendon interface. Achieving the proper balance in these criteria is
challenging.
The suture anchors are then inserted through superior accessory portals; this
provides an optimal angle of insertion into the bone. A large cannula through the
anterolateral portal facilitates easy passage of instruments in and out of the
subacromial space, minimizing trauma to the deltoid muscle. The sutures are
retrieved through this cannula, placed in a suture-passing device, and passed
through the tendon (Fig. 12.6 ). Once all sutures have been placed through the
tendon, arthroscopic knot tying devices are used to tie the sutures, reducing the
tendon to the bone. The long ends of the sutures are brought laterally and anchored
to the lateral cortex using another anchor or two (Fig. 12.6 ). This configuration
helps achieve the goals of secure fixation, minimal motion, and maximal contact
between the tendon and bone.