Biomechanical comparison of a single-row versus double-row suture anchor technique for rotator cuff repair.

BACKGROUND

Reestablishment of the native footprint during rotator cuff repair has been suggested as an important criterion for optimizing healing potential and fixation strength.

HYPOTHESIS: A double-row rotator cuff footprint repair will demonstrate superior biomechanical properties compared with a single-row repair.

STUDY

DESIGN

Controlled laboratory study.

METHODS

In 9 matched pairs of fresh-frozen cadaveric shoulders, the supraspinatus tendon from 1 shoulder was repaired with a double-row suture anchor technique: 2 medial anchors with horizontal mattress sutures and 2 lateral anchors with simple sutures. The tendon from the contralateral shoulder was repaired using a single lateral row of 2 anchors with simple sutures. Each specimen underwent cyclic loading from 10 to 180 N for 200 cycles, followed by tensile testing to failure. Gap formation and strain over the footprint area were measured using a video digitizing system; stiffness and failure load were determined from testing machine data.

RESULTS

Gap formation for the double-row repair was significantly smaller (P < .05) when compared with the single-row repair for the first cycle (1.67 +/- 0.75 mm vs 3.10 +/- 1.67 mm, respectively) and the last cycle (3.58 +/- 2.59 mm vs 7.64 +/- 3.74 mm, respectively). The initial strain over the footprint area for the double-row repair was nearly one third (P < .05) the strain of the single-row repair. Adding a medial row of anchors increased the stiffness of the repair by 46% and the ultimate failure load by 48% (P < .05).

CONCLUSION

Footprint reconstruction of the rotator cuff using a double-row repair improved initial strength and stiffness and decreased gap formation and strain over the footprint when compared with a single-row repair.

CLINICAL RELEVANCE: To achieve maximal initial fixation strength and minimal gap formation for rotator cuff repair, reconstructing the footprint attachment with 2 rows of suture anchors should be considered.