The bony landmarks should be marked before incision because this provides a visible layout for portal positioning. We typically use the standard posterior and anterior portals as well as combinations of anterolateral and lateral portals and, occasionally, a Neviaser portal. The posterior portal is established first, approximately 1 cm medial and 2 cm inferior to the posterolateral corner of the acromion, in the “soft spot.” Once this viewing portal is established, we place an anterior portal through the rotator interval using an outside-in technique with a spinal needle and standard arthroscopic cannula. We then perform a systematic glenohumeral inspection to examine for other shoulder pathology. Once this inspection is performed, we turn our attention to the articular aspect of the rotator cuff.

Certainly, large full-thickness rotator cuff tears are much easier to see. When inspecting the cuff from the articular surface, the surgeon can rotate the arm so that the entire undersurface of the cuff can be visualized from anterior to posterior. In addition, the arthroscope can be switched to the anterior portal for a different viewing perspective. A 70° arthroscope also may be used to improve visualization of far anterior or far posterior tears. In the case of a partial-thickness articular-surface tear, taking the arm out of traction and increasing abduction and/or rotation often helps with visualization of the tear. Gentle débridement of frayed tissue with a shaver may make it easier to see the edges of intact tendon. If the margins of a tear can be appreciated, then a probe of known size can be used to estimate the depth of the tear and guide treatment. At this point, it is best to evaluate the nature of the tissue on the bursal side of the rotator cuff. A spinal needle can be placed percutaneously through the cuff pathology and then monofilament suture passed through and retrieved through the anterior portal in the glenohumeral joint (Figure 2). This makes it easier to locate the affected portion of cuff from the subacromial side. At this point, the arthroscope and instruments are transitioned into the subacromial space. The lateral portal is placed using the outside-in localization of the spinal needle. This portal provides an excellent working position for a shaver or radiofrequency wand. A thorough bursectomy is performed, being diligent to débride far enough laterally to delineate the rotator cuff tear. Subacromial decompression should be performed only if acromial pathology is noted. Without the bursa obstructing the view, the rotator cuff can be inspected further. A full-thickness tear will be quite apparent, and the repair can begin. If a partial-thickness tear is present, the surgeon can identify the monofilament suture that was previously placed. The bursal side of the cuff is inspected. If this tissue is intact, then the tear is treated as a partial-thickness articular-surface tear.

For partial-thickness articular-surface rotator cuff tears, our treatment is guided by the Ellman classification
system⁶ (Table 1). A partial-thickness articular-surface tear less than 3 mm deep is considered an A1 tear and can be treated with débridement alone. A full-radius shaver works well for débriding degenerative and frayed tissue without damaging intact tendon. If the tear is between 3 and 6 mm (<50%), then treatment options include simple débridement or intratendon repair. An intratendon repair can be a favorable way of using intact tissue to the surgeon’s advantage because it provides a road map for cuff placement and decreases the amount of tissue that must heal. Our technique for intratendon repair, described below, has been described previously by other surgeons.⁹