To evaluate the biomechanical repair strength of two different suture anchor configurations utilized for type II superior labral anterior posterior (SLAP) lesions.
Standardized type II SLAP lesions were created in eight match paired cadaveric shoulders using a previously established protocol. Two different suture anchor configurations were used to repair the SLAP lesion. One arrangement (n=8) placed a suture anchor anterior and another posterior to the biceps labral insertion; a second arrangement (n=8) placed two suture anchors posterior to the biceps labral insertion. Specimens were mounted and a posterior directed load was applied to generate displacement of the biceps tendon.
The mean load required to displace the biceps labral insertion 2mm was 35.8N after repair of a type II SLAP lesion with a suture anchor placed anterior and one posterior (AP repair). SLAP lesions repaired with two suture anchors placed posterior (PP repair) to the biceps insertion required a mean load of 46.7N to displace the biceps labrum insertion 2mm.
When measuring load on the biceps anchor to cause 2mm of displacement, there was no significant difference in repair strength of type II SLAP lesions using the two different suture anchor configurations.
Anatomic studies have shown that the predominant pattern of biceps tendon insertion is posterior into the posterior-superior labrum. Also, the primary mechanism for SLAP lesions in overhead athletes is peel-back of the posterior superior labrum off the glenoid in the abducted, externally rotated shoulder. Placement of an anterior anchor could, theoretically, tension the anterior capsulolabral structures via the MGHL and SGHL attachments to the superior labrum and thus could result in a loss of external rotation. The results of this study suggest that there is no biomechanical advantage to placing an anterior anchor and so the use of two posterior anchors may be preferable in the overhead athlete in whom loss of external rotation cannot be tolerated.
© 2007 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.