Suture Anchor Biomechanics After Rotator Cuff Footprint Decortication.

PURPOSE

To identify the biomechanical consequences of violating the cortical shelf when preparing the greater tuberosity for suture anchor repair.

METHODS

Demographic information and bone mineral density were obtained for 20 fresh-frozen human humeri (10 matched pairs). Suture anchors were placed at a predetermined location in decorticated and non-decorticated settings after randomization. Anchors were tested under cyclic loads followed by load-to-failure testing. The number of cycles, failure mode, stiffness, and final pullout strength were recorded.

RESULTS

Nineteen specimens met the inclusion criteria for final testing. A significant difference in mean ultimate load to failure was seen between the non-decorticated specimens (244.04 ± 89.06 N/mm) and the decorticated humeri (62.84 ± 38.04 N/mm, P < .0001). Regression analysis showed positive correlations with female gender and decreased bone mineral density (P = .008 and P = .0005, respectively).

CONCLUSIONS

Decortication of the rotator cuff footprint significantly decreases the pullout strength of the suture anchor. Gender and bone mineral density also play a significant role in bone-anchor biomechanics and should be considered during repair.

CLINICAL RELEVANCE

Caution should be exercised when preparing the rotator cuff footprint before suture anchor placement because of the significant risk of early repair failure at the bone-anchor interface.