Two Techniques for Treating Medium-Sized Supraspinatus Tears: The Medially Based Single-Row Technique and the Suture Bridge Technique.

BACKGROUND

Arthroscopic rotator cuff repair emerged in the early 1990s, and the single-row repair technique (i.e., suture anchor[s] set at the center or laterally on the greater tuberosity) has shown promising outcomes; however, the healing rate of the repaired cuff is suboptimal. Although small to medium-sized rotator cuff tears have shown better clinical outcomes and structural healing than larger tears, healing failure still occurs.There are several factors that affect rotator cuff healing. The initial stiffness and strength of the repair, gap formation resistance, footprint coverage at the end of surgery, vascularity of the cuff, and mechanical stress on the repaired cuff are important factors. To improve tendon-to-bone healing, 2 repair techniques have been developed: the suture bridge technique and the medially based single-row technique. The suture bridge technique involves placing anchors in a 2-row fashion, with medial-row sutures from the medial anchors bridged over the footprint with lateral-row knotless anchors. The single-bridge technique has shown biomechanical superiority in terms of ultimate strength, stiffness, and gap formation resistance; however, these outcomes are achieved at the cost of relatively high tension at the suture-cuff junction, as well as interference with vascularity at the medial mattress sutures if medial mattress sutures are tied.Alternatively, the medially based single-row technique was proposed as a modification of the laterally based (traditional) single-row technique. This technique is combined with the creation of bone marrow vents (microfracture technique) lateral to the inserted anchor in the footprint to promote soft-tissue regeneration (called "neotendon") over the exposed footprint. The theoretical advantages of this technique include lower tension on the repaired cuff; better screw purchase beneath the subchondral bone, which avoids weaker cancellous bone on the peripheral area of the greater tuberosity; and avoidance or reduction of lateral shift of the muscle-tendon junction. However, these outcomes are achieved with relatively weaker initial fixation strength and by exposing the uncovered greater tuberosity footprint lateral to the repaired tendon edge.Both procedures provide equivalent outcomes as measured by functional and pain scores. At present, there is no decisive superiority in treating small to medium-sized supraspinatus tears.

DESCRIPTION

Arthroscopic subacromial decompression is performed in both techniques.For suture bridge fixation, the suture anchor is placed at the articular margin of the humeral head as the medial row, and both limbs of each suture are passed through the tendon approximately 5 mm lateral to the muscle-tendon junction of the rotator cuff in a mattress fashion. After the medial-row knots are tied, the suture limbs are brought into 2 lateral push-in anchors.For the medially based single-row repair, suture anchors are placed lateral to the articular margin. Each suture limb is passed through the tendon approximately 1 cm medial to the torn edge of the cuff. All sutures are tied with 7 half-hitches, avoiding a sliding knot.

ALTERNATIVES

Open or mini-open rotator cuff repair.Arthroscopic rotator cuff repair suture bridge technique without knot-tying.Arthroscopic transosseous (i.e., anchorless) rotator cuff repair.

RATIONALE

The suture bridge technique has achieved better mechanical properties and footprint coverage, and the medially based single-row technique has achieved lower tension on the repaired construct with neotendon regeneration. These techniques are the opposite concept as coverage-oriented and tension-oriented techniques, respectively. To our knowledge, there is presently no study showing that either of these 2 techniques is better than the other. With that said, the author prefers the medially based single-row technique in cases with degenerative tendon tissue, especially among elderly patients with relatively short tendon substance and with preoperative stiffness because lowering the tension on the repaired construct would be more important than coverage of the greater tuberosity.

EXPECTED OUTCOMES

Published data have not shown significant differences in the clinical outcomes and cuff integrity between these 2 techniques, with no decisive superiority when treating small to medium-sized supraspinatus tears. The choice between these techniques is solely the decision of the surgeon; however, medial cuff failure has been reported only when using the suture bridge technique, and incomplete healing was more frequent among medially based single-row techniques. One should consider the risks of medial cuff failure and incomplete healing of the repaired cuff before choosing the repair technique for medium-sized supraspinatus tears.

IMPORTANT TIPS

The proposed risk factors for medial cuff failure in the suture bridge technique include:○ A mattress suture configuration placed at the muscle-tendon junction○ Aggressive rehabilitation○ Use of a large-diameter suture passer○ Application of a sliding knot○ High-stress concentration around the medial knotsThe proposed risk factors for incomplete healing in the medially based single-row techniqueare:○ Lower mechanical properties (initial stiffness and strength, gap formation resistance) in the repaired site○ Lower number of sutures.