A posteromedial working portal for arthroscopic subacromial decompression and acromioclavicular joint arthroplasty.

Arthroscopic subacromial decompression is traditionally performed through a posterolateral viewing portal and a lateral working portal. We describe the same procedure by using a posterolateral viewing portal and a posteromedial working portal. Because this portal is in the same sagittal plane as the ipsilateral acromioclavicular joint, it allows performing an arthroscopic excision arthroplasty of this joint.