Small to Medium Rotator Cuff Tears

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CHAPTER 20 Small to Medium Rotator Cuff Tears

Arthroscopic rotator cuff repair (ARCR) has become the gold standard for treatment of the vast majority of rotator cuff lesions.¹^–¹⁶ Early concerns about repair integrity and durability have led to the anticipated evolution in anchors, suture material and, most importantly, surgical technique. We now have at our disposal an armamentarium of anchors made not only of metal, but poly-L-lactic acid, self-reinforced poly-DL-lactic acid, and polyetheretherketone (PEEK). Suture material has been vastly improved as a result of the introduction of Fiberwire and the many comparable enhanced strength suture materials.

The advances in technique during this time have also been remarkable. Along with improved anchors and stronger suture material, we have realized vast improvements in instrumentation and the application of these devices to repairs. The advent of double-row repair (DR) has provided the potential for improved footprint restoration, repair longevity, and clinical outcomes.

Despite these improvements and advancements, the learning curve an orthopedic surgeon experiences in ARCR remains moderately steep. However, the many national and wrlswide continue to offer surgeons the opportunity to obtain basic and advanced skills. It is the intent of this chapter to discuss my approach to the repair of medium- sized rotator cuff tears, one of the easier lesions to repair and a good one with which to begin your learning experience.

PREOPERATIVE CONSIDERATIONS

Patients with small and medium-sized rotator cuff tears often present with only a modicum of symptoms. In contrast to those individuals with larger lesions, in whom weakness and severe functional restrictions play a larger role, these patients often are able to maintain many of their daily activities, albeit with a variable level of pain. The cause of the tear may be well defined, especially if there is a history of a traumatic event. However, more often the patient will be unable to attribute the current shoulder complaints to any known injury but rather relate it to a gradual, insidious onset of shoulder pain, progressive in nature, and one that has resulted in functional limitations and night pain. One of the hallmarks of rotator cuff pathology, night pain, is thought to be caused by the dependent recumbent position in bed, resulting in increased edema of the cuff tissues, causing secondary pain. It is universally present in patients presenting with rotator cuff problems.

Physical examination in patients with small and medium tears, as for almost all patients with cuff pathology, will demonstrate certain positive findings such as impingement signs (hyperforward flexion and internal rotation at 90 degrees flexion), painful arc (from 80 to 120 degrees elevation), a positive Jobe test (pain with resisted elevation in the scapular plane), and subacromial crepitus. Although painful, strength testing will demonstrate only a slight decrease, in contrast to larger lesions, which may involve posterior tendons, with a resultant decrease of external rotation strength. Pathology of the acromioclavicular joint, caused by preexisting arthritis and/or a secondary inflammatory arthropathy, will be manifested by pain on cross-arm maneuvers, internal rotation, and direct palpation.

Standard imaging studies are used to define the patient’s pathology and need for intervention. Three routine views on shoulder films—anteroposterior (AP), outlet, and axillary lateral views—are always obtained, but magnetic resonance imaging (MRI) remains the principal diagnostic modality. Coronal oblique, saggital, and axillary images allow the surgeon to determine the presence of a tear and its dimensions in the anterior (posterior and medial) lateral planes. Furthermore, the MRI scan can provide additional information as to the extent of fatty infiltrate of the tear, its potential reparability, and pertinent glenohumeral pathology.

With this infomation, the patient is appropriately counseled on the advisability of surgery, including its associated risks and potential outcomes. There has been ongoing debate regarding the need for surgical intervention in these smaller tears; however, most surgeons recognize the potential for enlargement of any tear over time, especially those with a traumatic cause. Currently, for any patient with a well-defined traumatic event, and otherwise normal shoulder function prior to that event, the recommendation is for immediate repair. Those individuals with no history of substantial trauma, yet ongoing symptoms and MRI confirmation of a tear, conservative nonsurgical care is offered, with the recommendation for follow-up and possible repeat MRI at 4 to 6 months. If symptoms are persistent, or are unrelieved with conservative measures, surgery and repair are recommended. Also, those patients with significant comorbidities that could strongly affect healing and/or rehabilitation, and those with compliance issues, are treated with conservative modalities, and surgery is reserved for those with increasing symptoms.

ARTHROSCOPIC ROTATOR CUFF REPAIR

Setup

All patients undergoing an arthroscopic rotator cuff repair in our facility have an interscalene block. This regional anesthesia is administered by the anesthesia staff at least 30 minutes prior to the case. The block uses long-acting local anesthetics and steroid, which enhances its longevity, providing upward of 24 to 36 hours of analgesia. Most patients have a concomitant general anesthetic to provide hypotensive anesthesia for enhanced visualization during arthroscopy. In the past, selective criteria were used to determine who best should have additional general anesthesia; however, I have found that the hypotension provided with the general anesthetic improves visualization greatly and is thought to be of such low risk to the patient because of the lesser amount of anesthetic agent needed when used with a block. Thus, I routinely use a block augmented with general anesthesia. Those patients with pulmonary compromise are excluded from having a block because of the risk of phrenic nerve palsy and respiratory compromise.

All cases are performed with the patient in the lateral decubitus position, allowing ready access to the posterior, anterior, and superior aspects of the shoulder while holding the arm in a position of slight abduction, thereby facilitating approximation of the free tendon edge to the region of the greater tuberosity (Fig. 20-1). The arm is rotated as needed to optimize anchor placement and reduce tension during suture tying. In most patients, 10 pounds of traction at approximately 30 to 40 degrees of abduction is more than adequate to provide the proper shoulder position. Anesthesia is moved out of the immediate operative field to allow unimpeded access to the entire shoulder region.

FIGURE 20-1 Patient in lateral decubitus position, with arm abducted 40 degrees.

Every procedure begins with a basic set of instruments, including a simple knot pusher, ring grabber or crab claw device for retrieving individual sutures, set of cannulated suture passers, cannula for fluid management, and various suture retrievers (Fig. 20-2). Additional instruments can be added as neededs.

FIGURE 20-2 Basic set of instruments, including knot pusher, Liberator knife (Conmed Linvatec, Largo, Fla), ring grasper, punch baskets, and suture retriever.

Portals

All arthroscopic repairs require three principal portals and an additional ancillary anterior portal. The viewing portal is located 1 cm medial and 2 cm inferior to the posterolateral corner of the acromion (Fig. 20-3). The arthroscopic subacromial decompression (ASD) instrument portal is located immediately anterior to the finish line, a line drawn perpendicular to the lateral margin of the acromion, beginning at the posterior extent of the acromioclavicular joint and 2 to 3cm lateral to the lateral margin of the acromion. The anchor portal location is determined during subacromial viewing using the needle localization technique; it is typically at the anterolateral corner of the acromion. An additional fourth portal may be made anterior to the acromion, called the waiting room portal. I use this for large tears in which three or more anchors and six or more sutures are involved. This portal allows me to dock sutures that are not being worked with anteriorly to free up the viewing area while posterior sutures are tied. This aids greatly in suture management.

FIGURE 20-3 The patient is in the lateral decubitus position, with the right shoulder exposed. The viewing portal is located 1 cm medial and 2 cm inferior to the posterolateral corner of the acromion. The ASD instrument portal is located anterior to the finish line and 2 to 3cm inferior to the lateral margin of the acromion. The anchor portal is at the anterolateral corner of the acromion. The waiting room portal is made just off the anterior edge of the acromion.

Once the need for a repair has been determined, all portals are secured with cannula. The size of the cannula is dependent on the anticipated use of that portal. For example, the posterior portal is often used also for instrument access with the Spectrum (Conmed Linvatec, Largo, Fla) cannulated suture passer. This device requires at least an 8-mm opening and thus an 8-mm cannula. The anchor portal, however, is used almost exclusively for anchor insertion and knot tying, so a smaller 5-mm cannula is adequate. The lateral, or instrument portal, is sized according the instrument to be used for that repair. In most cases, and with most instruments, a 6- to 7-mm cannula is acceptable. Use of a cannula greatly diminishes fluid extravasation into the soft tissue, minimizes overall fluid requirements, and enhances visualization by maintaining hydrostatic pressure in the subacromial space. Cannulas also allow the surgeon to move the scope freely from portal to portal to improve visualization and prevent soft tissue from being entangled with sutures during passage and tying.

Glenohumeral Inspection

All shoulder procedures, whether they are ARCR, instability, or ASD, begin with a thorough inspection of the glenohumeral joint to identify and treat other associated pathology, such as superior labrum anteroposterior (SLAP) lesions, capsulolabral disruptions, biceps tears, and loose bodies. Partial-thickness tears of the rotator cuff can be assessed, localization sutures placed and, if a high-grade lesion is encountered, a formal débridement of the lesion with conversion to a full-thickness tear or a transtendinous repair may be performed, preserving the intact bursal fibers. If a large, fixed, retracted tear is encountered, this is the optimal time to begin the capsulotomies and releases.

Acromioplasty

Although there has been debate regarding the need and efficacy of ASD in ARCR,¹⁷^–¹⁹ an acromioplasty allows for enhanced visualization during the repair and increased room for instrumentation, and lessens the likelihood of later impingement of the repaired cuff. The ASD should require no more than 10 to 15 minutes to complete. To that end, in all chronic and many acute full thickness rotator cuff tears, I routinely perform a concomitant ASD. Viewing from the posterior portal, a bursectomy is performed to visualize the inferior surface of the acromion. If a large rotator cuff tear has been identified, the bursectomy is carried around the anterior, lateral, and posterior gutters to improve visualization and facilitate instrumentation of the subscapularis and/or infraspinatus tendons. When the bursectomy is complete, a radiofrequency (RF) device removes all residual soft tissue from the under surface of the acromion and releases the coracoacromial (CA) ligament from its attachment on the anteroinferior aspect of the acromion (Fig. 20-4). This is only a CA ligament release, not a resection. The burr is introduced from the lateral portal and the decompression begun at the anterolateral corner, working both medial and posterior (Fig. 20-5). An adequate decompression is achieved when the acromioplasty is tapered and terminates at or about the finish line (the line drawn at the time of initial portal placement; see earlier). Finally, the decompression is completed by moving the arthroscope to the lateral portal, bringing the burr in from the posterior portal and finished with a cutting block technique.