Rotator Cuff Repair (Cadaver Shoulder)

Abstract

Rotator cuff tears represent the vast majority of shoulder disorders treated by orthopaedic surgeons. From partial-thickness tears in overhead throwing athletes to full-thickness tears in the elderly, the prevalence of rotator cuff tears continues to increase over time. While some cases are asymptomatic, most patients with rotator cuff tears report shoulder pain, limited range of motion, and nighttime pain with difficulty sleeping on the affected shoulder. When nonsurgical treatment is insufficient in relieving the symptoms, arthroscopic rotator cuff repair becomes a viable option for many patients. Here we present the case of a rotator cuff repair of a full-thickness tear that extends into the infraspinatus on a cadaver shoulder in the beach chair position. The tear was repaired by placing an anchor, retrieving and passing three suture arms, and tying the suture. We outline the natural history, preoperative care, intraoperative technique, and postoperative considerations of rotator cuff repairs.

Keywords

Orthopaedics; arthroscopy; shoulder; rotator cuff; cadaver.

Case Overview

Background

The likelihood of rotator cuff tears increases with age, with a reported prevalence of 80% in patients over 60 years old.¹ If left untreated or treated nonoperatively, symptomatic patients with a partial-thickness tear can develop a full-thickness tear or worsen their already full-thickness tear.² Another common group affected by rotator cuff tears is athletes that perform overhead throwing motions such as baseball pitchers. Although less common, a full-thickness rotator cuff tear can make it extremely difficult for professional baseball pitchers to return to their same level of play before the injury.³

Surgical options for treating a rotator cuff tear include a diagnostic shoulder arthroscopy and repair of the torn ligaments with anchors. The anchors are held in place with the suture arms. The number of anchors depends on the size of the tear.

Focused History of the Patient

It is important to obtain a thorough history regarding the mechanism, timeline, and progression of the injury. Important questions to ask include:⁴

• Where is the location of the pain?
• When was the onset of the pain?
• Was there a predisposing injury or trauma?
• Is there pain with motion?
• Is there an equal range of motion on both sides?
• Is there pain with sleeping on the affected side?
• Has there been a previous shoulder injury or surgery?
• What is the patient’s occupation? How is the shoulder used in daily activities?
• Does the patient have any chronic conditions such as osteoporosis?

Physical Exam

A thorough physical exam should include the following:

• Visually inspect the shoulder for skin changes, scars, swelling, symmetry, and muscular atrophy.
• Palpate the acromioclavicular (AC) joint and surrounding bony prominences. Palpate the deltoid, trapezius, rotator cuff, and biceps tendons.
• Check the active and passive range of motion (flexion, extension, abduction, adduction, internal and external rotation).
  Special tests:⁵
  • Neer impingement sign: Place one hand on the patient’s scapula and use other hand to take the patient's internally rotated arm by the wrist and place it in full flexion.
  • Jobe’s test: Have the elbow in full extension with the shoulder abducted 90 degrees and horizontally adducted 30 degrees. Then internally rotate the arm and press down while the patient resists.
  • External rotation lag sign: Flex the elbow to 90 degrees and maximally externally rotate the shoulder and instruct the patient to hold that position. If the arm starts to drift internally, the test is positive.
  • Hornblower’s sign: Abduct and externally rotate the shoulder 90 degrees and ask the patient to hold that position. If the arm falls into internal rotation, the test is positive.  
  • Belly press test: Instruct patient to internally rotate the shoulder and press their palm into their belly. The test is positive if the elbow drops back.

Imaging

The MRI is the gold standard for evaluating a rotator cuff tear.⁵ It provides information regarding the shape and size of the tear along with visualization of humeral head cysts in chronic rotator cuff tears. Other imaging can include an anteroposterior (AP) view of the shoulder and an ultrasound for dynamic testing. Radiographic images provide information about calcification in the tendons and ligaments, and have been used to characterize tears into different classification systems.^6, 7 The ultrasound is inexpensive and readily available but is highly user dependent and is unable to evaluate other intra-articular pathology.⁸ Only the MRI, however, is able to evaluate the integrity of the overall rotator cuff and determine if the tear is repairable.

Natural History

The supraspinatus, infraspinatus, teres minor, and subscapularis make up the rotator cuff, and all act to provide stability to the glenohumeral joint. A partial-thickness tear is a tear through a part of one of these tendons, while a full-thickness tear is a tear through the entire tendon, often extending to other tendons. Full-thickness, chronic degenerative tears are commonly seen in older patients and involve microtrauma to the supraspinatus, infraspinatus, and teres minor (SIT) muscles. This type of tear fails to heal completely and can progress to a bigger tear with worsening symptoms.² Acute SIT tears can also be seen in patients > 40 years of age with shoulder dislocations.⁹ Partial-thickness tears are more commonly seen in overhead throwing athletes like baseball pitchers due to the repetitive throwing motion at high velocities. The posterior supraspinatus and superior infraspinatus rub against the glenoid rim and labrum, leading to internal impingement and a rotator cuff tear.¹⁰

Options for Treatment

A rotator cuff tear can be treated nonoperatively with immobilization in a sling and NSAIDs for pain control. This should be followed with physical therapy to increase the range of motion and strength of the shoulder. If there is persistence of pain or decreased range of motion and strength after nonoperative treatment, then arthroscopic repair should be considered. Arthroscopic repair is generally recommended for complete tears in patients under 40 years of age and acute tears from traumatic injuries.¹¹ All asymptomatic tears should be treated nonoperatively.¹¹

Rationale for Arthroscopic Repair

Arthroscopic repair of the shoulder is preferred over open repair due to smaller incisions, fewer risks of bleeding or injury to vasculatures, and a faster recovery and return to baseline activity.¹² The surgeon is also better able to visualize the entire joint with the arthroscope. 

Special Considerations

Contraindications for rotator cuff repair include distorted anatomy that hinders proper portal placement for arthroscopy and infection at the site of portals. Special care must be taken when performing arthroscopies on patients with severely increased body mass index.¹³ Other contraindications include patients who are unable to follow the postoperative rehabilitation protocol such as immobilization and physical therapy.¹⁴ Complications from a rotator cuff repair include shoulder stiffness, neurovascular injury, swelling, and infection.¹⁵

Discussion

Advancements in shoulder arthroscopy have improved the treatment options for rotator cuff tears and largely replaced open shoulder repairs. In this cadaver shoulder case, we repair a full-thickness rotator cuff tear in the beach chair position using a posterior portal for visualization and a superior lateral portal for anchor placement. The two common patient positionings for arthroscopy are the lateral decubitus and beach chair positions. Advantages of the beach chair position include ease of examination under anesthesia due to upright anatomic position, decreased neovascularization during portal placement, and reduced surgical time.¹² Some disadvantages to the beach chair position include increased vascular resistance and increased risk of hypotension and bradycardia.¹² Regional anesthesia is the preferred method of anesthetizing the patient and peripheral nerve blocks can be used to reduce the risk of postoperative complications.⁹ 

The posterior portal is the first portal developed in shoulder arthroscopy and enters the soft spot between the humeral head and the glenoid.¹² This allows for proper visualization of the entire shoulder joint and the ability to look for any concomitant pathology present with the rotator cuff tear. It is also used to characterize the shape and size of the tear. In this case, we found a full-thickness tear of the supraspinatus that extended 3 cm into the infraspinatus. A tear of this size usually requires three anchor placements, but we placed one for teaching purposes. The anchors were drilled and sutured to the bone using a superior lateral portal.

One of the most common complications associated with rotator cuff repair is shoulder stiffness with reported rates ranging from 5–30%.¹⁶ Risk factors associated with the development of shoulder stiffness after arthroscopy include calcific tendinitis, concurrent labral repair, tear size less than 3 cm, and limited preoperative range of motion.¹⁷ A recent review paper concluded that there were no differences in functional outcomes and risk of re-tears between an accelerated versus conservative rehabilitation protocol following rotator cuff repair.¹⁸ Future studies need to examine the rate of shoulder stiffness using a rehabilitation protocol that limits immobilization and encourages an early range of motion exercises. A few studies have also attempted to inject anti-adhesive agents to decrease the postoperative stiffness with inconclusive results.^19-21 Future advancements in arthroscopy will require implementing new and improved techniques to reduce the risk of postoperative shoulder stiffness following rotator cuff repair.

Equipment

No special equipment used.

Disclosures

Nothing to disclose.