Optimal Lateral Row Anchor Positioning in Posterior-Superior Transosseous Equivalent Rotator Cuff Repair

Abstract

Background:The optimal placement of suture anchors in transosseous-equivalent (TOE) double-row rotator cuff repair remains controversial.Purpose:A 3-dimensional (3D) high-resolution micro–computed tomography (micro-CT) histomorphometric analysis of cadaveric proximal humeral greater tuberosities (GTs) was performed to guide optimal positioning of lateral row anchors in posterior-superior (infraspinatus and supraspinatus) TOE rotator cuff repair.Study Design:Descriptive laboratory study.Methods:Thirteen fresh-frozen human cadaveric proximal humeri underwent micro-CT analysis. The histomorphometric parameters analyzed in the standardized volumes of interest included cortical thickness, bone volume, and trabecular properties.Results:Analysis of the cortical thickness of the lateral rows demonstrated that the entire inferior-most lateral row, 15 to 21 mm from the summit of the GT, had the thickest cortical bone (mean, 0.79 mm; P = .0001), with the anterior-most part of the GT, 15 to 21 mm below its summit, having the greatest cortical thickness of 1.02 mm (P = .008). There was a significantly greater bone volume (BV; posterior, 74.5 ± 27.4 mm3; middle, 55.8 ± 24.9 mm3; anterior, 56.9 ± 20.7 mm3; P = .001) and BV as a percentage of total tissue volume (BV/TV; posterior, 7.3% ± 2.7%, middle, 5.5% ± 2.4%; anterior, 5.6% ± 2.0%; P = .001) in the posterior third of the GT than in intermediate or anterior thirds. In terms of both BV and BV/TV, the juxta-articular medial row had the greatest value (BV, 87.3 ± 25.1 mm3; BV/TV, 8.6% ± 2.5%; P = .0001 for both) followed by the inferior-most lateral row 15 to 21 mm from the summit of the GT (BV, 62.0 ± 22.7 mm3; BV/TV, 6.1% ± 2.2%; P = .0001 for both). The juxta-articular medial row had the greatest value for both trabecular number (0.3 ± 0.06 mm–1; P = .0001) and thickness (0.3 ± 0.08 μm; P = .0001) with the lowest degree of trabecular separation (1.3 ± 0.4 μm; P = .0001). The structure model index (SMI) has been shown to strongly correlate with bone strength, and this was greatest at the inferior-most lateral row 15 to 21 mm from the summit of the GT (2.9 ± 0.9; P = .0001).Conclusion:The inferior-most lateral row, 15 to 21 mm from the tip of the GT, has good bone stock, the greatest cortical thickness, and the best SMI for lateral row anchor placement. The anterior-most part of the GT 15 to 21 mm below its summit had the greatest cortical thickness of all zones. The posterior third of the GT also has good bone stock parameters, second only to the medial row. The best site for lateral row cortical anchor placement is 15 to 21 mm below the summit of the GT.Clinical Relevance:Optimal lateral anchor positioning is 15 to 21 mm below the summit of the greater tuberosity in TOE.

Cell lineage tracing and functional assessment of supraspinatus tendon healing in an acute repair murine model

“…The loss of mechanical loading and excessive inflammation may also explain the loss in cortical and trabecular bone at the insertion site. This is consistent with findings in human cadaver shoulders showing impaired bone volume and trabecular properties with torn rotator cuff tendons compared to intact 37 . These results indicate that while restoration of the tendon to bone interface remains a critical problem, the loss of tendon is also a key clinical challenge that cannot be overcome by surgical repair alone.…”

Optimizing Anchor Placement for Cone-Shaped Rotator Cuff Tears

“… 3 , 4 , 5 , 6 Therefore, this juxta-articular positioning allows for placement of the medial-row anchors into denser bone, allowing for higher pullout strength from the anchor, whether in normal or osteopenic bone. 7 , 8 Through the use of this technique, surgeons can be confident in precisely placing anchors just adjacent to the articular cartilage on the medial footprint to optimize the final repair construct.…”

Anchor Site Fracture Following Arthroscopic Rotator Cuff Repair – A Case Report and Review of the Literature

“…One may argue that this was not achieved in our case (approx. 8–10 mm below summit) and may have favored instability at a much weaker site [ 29 ]. Interestingly, the anchors with a larger diameter were used within the lateral row in our patient (5.5 mm vs. 4.75 mm, read above).…”