The goal of rotator cuff repair is to obtain secure, tension-free fixation of the tendon to the anatomic footprint. Arthroscopic techniques include single-row (SR), double-row (DR), and transosseous-equivalent (TOE) repair. Several biomechanical studies have shown superiority of DR and TOE repair over SR repair. Despite biomechanical superiority of DR over SR repair, clinical outcomes have not found any significant difference between the two techniques at short-term follow-up. Consistent with biomechanical outcomes, retear rates are lower for DR repair than SR repair; however, the clinical relevance of a rotator cuff retear remains controversial.
9 Arthroscopic Rotator Cuff Repair: Single-Row, Double-Row, and Transosseous-Equivalent Repair
The goal of rotator cuff repair is to obtain secure, tension-free fixation of the tendon to the anatomic footprint so that biologic tendon-to-bone healing can occur
Open transosseous rotator cuff repair had been considered the gold standard technique, and has performed well in clinical and biomechanical studies
The transition from open to arthroscopic repair has brought about an evolution of techniques that include single- and double-row constructs, and more recently transosseous-equivalent (TOE) or suture-bridge repair
The optimal technique is still controversial and the superiority of one construct over another is not well established.
II. Single-row (SR) repair
SR repair (▶ Fig. 9.1a ) of a full-thickness rotator cuff tear utilizes a linear row of suture anchors (typically double- and/or triple-loaded) inserted into the medial or lateral aspect of the rotator cuff footprint depending on tendon mobility
Suture anchors inserted at 90 degrees to the surface of the rotator cuff footprint have been shown to have less gap formation and increased cyclic load to failure when compared to those inserted at the “deadman’s angle” of 45 degrees 1
Suture limbs are passed through the tendon in a variety of suture configurations (simple, mattress, modified Mason-Allen, etc.)
The advantages of this technique are that it is easy, quick, and does not require a large amount of residual tendon length.
SR repair is recommended in tears where there is <1 cm of remnant tendon length 2
Most published data suggest that an SR repair is sufficient for small and medium sized rotator cuff tears (<3 cm). 3
III. Double-row (DR) repair
DR repair involves placing a medial row of suture anchors along the humeral head articular margin and a second row of anchors on the lateral aspect of the footprint
Suture limbs from the medial row are passed 5 mm distal to the musculotendinous junction in a mattress configuration; lateral row sutures may be passed in a simple or mattress configuration
Care must be taken to avoid excessive tensioning of the repair; this can be achieved by ensuring that adequate tendon length and excursion are available
An advantage of this technique over SR repair is that it is biomechanically superior and provides improved footprint restoration which theoretically allows a greater surface area for tendon-to-bone healing to occur
Disadvantages of this technique include increased operating room time, increased difficulty, and anchor crowding in the footprint
Most published data suggest that DR repair may be preferable for large and massive tears with adequate tendon length 3
Significant tissue loss or remnant tissue on the lateral footprint precludes the use of a DR repair.
IV. Transosseous-equivalent (TOE) repair
TOE (▶ Fig. 9.1c ) was introduced by Park et al. in 2006
TOE repair, also known as a suture-bridge repair, is a modification of the DR repair where the medial row suture limbs are linked to knotless anchors on the lateral humeral cortex; this differs from the DR repair where each suture anchor acts as a separate point of fixation
Passage of medial row sutures through the musculotendinous junction should be avoided because of the risk of medial row failure 5
Since the lateral anchors are inserted in the lateral cortex, it avoids the problem of suture anchor crowing in the footprint seen with DR repair
Another advantage is that it provides a broader surface area of contact similar to transosseous repair; this differs from the “spot-weld” fixation seen with DR repair
A major disadvantage to using this technique is that the vascular supply to the tendon may be compromised by the increased pressure over the bursal side of the tendon.
V. Biomechanical outcomes
The biomechanical properties necessary to achieve successful rotator cuff repair include a high initial fixation strength (measured as ultimate load to failure), minimum gap formation at the time of repair, maintenance of mechanical stability under cyclic loading, and optimization of the biology of the tendon–bone interface until healing occurs
Several technical parameters have been used to effect rotator cuff repair strength including modifying suture anchor configuration, modifying suture configuration (i.e., simple suture, mattress suture, modified Mason-Allen, etc.), and altering the number and type of sutures used
A recent systematic review of 40 biomechanical studies found that the type of suture and the number of suture limbs that pass through the tendon may be stronger predictors of fixation strength than the construct type: 12
Four major findings were revealed: 12
The number of suture limbs passed through the tendon may be a stronger predictor of ultimate failure load than the number of sutures used
Although TOE repair achieved the highest ultimate load to failure, no significant difference was found between repair types when stratified by the total number of suture limbs that passed through the tendon
A higher number of suture limbs that passed through the tendon and the use of TOE repair increased the risk of developing a type 2 retear
Using wide sutures instead of standard sutures correlated with higher failure load.
VI. Functional outcomes
Several Level I randomized controlled trials (RCTs) evaluating clinical outcomes after SR and DR repairs have not found any significant difference between the two techniques at short-term follow-up 13 – 17
However, there is some evidence to suggest clinical superiority of DR repair over SR repair when performed for larger tears
A Level I RCT of 160 patients with a full-thickness rotator cuff tear found superior clinical outcomes at 2 years with DR repair compared to SR repair, especially for tears >3 cm 21
A Level II cohort study of 78 patients with a full-thickness rotator cuff tear >3 cm found significantly improved subjective outcomes (Constant and American Shoulder and Elbow Surgeons [ASES] scores) at 2 years after DR repair when compared to SR repair; however, no significant differences between techniques were found when all tear sizes were included 22
A Level II RCT of 53 patients with an initial tear size of >3 cm in sagittal length underwent SR and DR repairs with a minimum 2-year follow-up. The patients with initial tears >3 cm in sagittal length had improved strength at 2 years when treated with DR repair compared with SR repair 23
VII. Structural outcomes
The incidence of retear after rotator cuff repair varies widely in the literature
A classic study using ultrasound to evaluate cuff integrity found a retear incidence of 94% after SR repair of tears measuring >2 cm 31
Patient’s age, initial tear size, and fatty degeneration of the supraspinatus are independent risk factors for a rotator cuff retear 40
The clinical relevance of a rotator cuff retear remains controversial; although some studies suggest that repair integrity does not affect clinical outcomes, 41 – 43 several studies have shown that retears affect functional scores 44 – 49
Similarly, studies have shown superior healing rates for TOE repair compared to SR repair, particularly for larger and massive tears; 49 , 51 – 54 however, the retear rates of small tears <1 cm do not appear to differ between TOE and SR techniques 50 , 51
To date, no Level I study has shown that TOE technique yields superior healing rates compared with conventional DR repair; a recent systematic review found that retear rates for DR and TOE repairs did not differ significantly from each other in any tear size category.