Anatomical relationships of the transmuscular portal to its surrounding structures in arthroscopic treatment of superior labrum anterior posterior lesions: A cadaveric study and preliminary report

Özet

Objective: This study aims to investigate the anatomical relationships of the transmuscular portal to its surrounding structures in arthroscopic treatment of superior labrum anterior posterior (SLAP) lesions in a human cadaveric model.Methods: In this anatomic study, bilateral shoulder girdles of 12 adult formalin embalmed cadavers were used. All cadavers were male,and the mean age was 63.4±7.3 years. The portal entry point was determined as midway between the anterior and posterior borders of theacromion, approximately 1 cm lateral from the edge of the acromion. After a guidewire was placed in the glenoid cavity at the 12 o’clockposition where the SLAP lesion typically occurs, a switching stick was inserted there. Each glenoid was then drilled with a 2.4 mm drillthrough an arthroscopic cannula. Subsequently, anatomical dissection was executed to assess the relationship of the transmuscular portalwith the suprascapular nerve, axillary nerve, supraspinatus tendon, acromion, and biceps tendon. Lastly, the shortest distance betweenthe aforementioned structures with the drill was measured by a sensitive caliper to determine whether there was a penetration of thestructures. Differences between the right and left sides were analyzed.Results: The mean distance between the portal and the axillary nerve was 55.5 mm±6.0 mm, and the mean length of the suprascapularnerve was 61.2 mm±7.0 mm. The mean distance between the portal and the supraspinatus tendon was 2.8 mm±1.5 mm. No penetrationof the axillary nerve, suprascapular nerve, and supraspinatus tendon was observed in any cadaver. No differences were detected formeasured anatomical parameters between the right and left sides (p>0.05).Conclusion: Findings from this cadaveric study revealed that the transmuscular portal may allow for a reliable anchor placement withoutany nerve or tendon penetration during arthroscopic SLAP repair.Level of Evidence: Level V