Scapulothoracic Arthroscopy for Snapping Scapula Syndrome

Abstract

Background:

Snapping scapula syndrome (SSS) is a disruption of the normal smooth motion of the scapulothoracic joint leading to clicking or “snapping” which can be painful or painless. There are a variety of etiologies with first-line treatment being conservative. If patients fail extensive nonoperative treatments, then surgery may be considered. Although technically challenging, arthroscopic treatment is recommended due to its decreased morbidity and improved cosmesis.

Indications:

We present a 21-year-old man with a 2-year history of mechanical popping and crepitus with overhead and scapulothoracic motion of his left arm. After failing an extensive trial of conservative therapy, the patient underwent scapulothoracic arthroscopy with bursectomy and partial resection of the superomedial border of the scapula.

Technique Description:

The patient is positioned prone with the operative arm behind the back to elevate the medial border off the chest wall. The scapula is outlined. Two arthroscopic portals are used; the superior portal is 3 cm medial to the medial border of the scapula at the level of the scapular spine and the inferior portal is 4 cm inferior to this at the inferomedial angle of the scapula. Viewing is typically done from the inferior portal, and the superior portal is used for resection of the bursa and superomedial border of the scapula. A shaver and ablator are used to perform a bursectomy and expose the superomedial border of the scapula. An arthroscopic bur is used to partially resect the superomedial border of the scapula at approximately 3.5 cm wide and 2 cm deep.

Results:

Although there are limited studies examining outcomes after scapulothoracic arthroscopy, the current literature suggests that scapulothoracic arthroscopy is effective in improving crepitus, pain, and clinical outcome scores.

Discussion/Conclusion:

In cases of SSS which have failed exhaustive conservative therapy, arthroscopic bursectomy and partial bony resection can be an effective treatment option with minimal invasiveness, improved cosmesis, and early return to activities. Proper patient positioning and careful portal placement are critical to avoid iatrogenic injury, particularly to neurologic structures.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

Scapulothoracic Arthroscopy for Snapping Scapula Syndrome presented by Dr James Bradley, clinical professor of Orthopedic Surgery, University of Pittsburgh Medical Center, and head team physician for the Pittsburgh Steelers, along with Michael Nammour, Orthopedic Sports Medicine Fellow.

These are our disclosures.

Snapping scapula syndrome is caused by disruption of the normal smooth motion of the scapulothoracic joint. ¹ The etiology can be divided broadly into 4 categories: first, bony causes such as osteophytes, a prominence of the superior medial border of the scapula known as Luschka tubercle, malunion of rib fractures, abnormal scapula curvature, or benign or malignant bone tumors, such as osteochondromas or sarcomas.^1,6,7 Second, soft tissue causes most commonly including bursitis, muscular asymmetry or weakness, as well as soft tissue masses such as elastofibromas.^1,6,7 Third, postural causes such as kyphosis or scoliosis and finally, neurologic causes such as abnormalities of cranial nerve 11 or the long thoracic nerve and associated scapular winging patterns.^1,6,7

The presentation of snapping scapula syndrome is typically associated with pain with overhead activities, especially with repetitive activities as seen in swimmers and throwers.^2,4,8 This can be associated with popping or snapping with active range of motion. ⁸ Patients may present with tenderness over the superomedial border of the scapula or paraspinal muscles, along with palpable or audible crepitus with shoulder abduction.^1,7 It is always important to assess for scapular winging because when present, it raises concern for an underlying mass or neurologic condition. Imaging is necessary to rule out bony or soft tissue abnormalities such as masses.^5,7 Plain x-ray views include AP, scapular, and axillary views. Computed tomography (CT) scans, particularly those with 3D reconstructions, are helpful in evaluating the complex anatomy of the scapular pathology. Magnetic resonance imaging scans are most useful for identifying soft tissue masses and bursitis. ⁷

Management of snapping scapula syndrome begins with a trial of nonoperative treatment, including rest, activity modification, nonsteroidal anti-inflammatory medications, scapulothoracic injections, and physical therapy focusing on scapulothoracic muscle and postural training.^6,7,8 Patients with soft tissue or bony pathology are less likely to be successfully treated nonoperatively.^2,4,8 Operative management is appropriate after the failure of nonoperative treatment. Both open and arthroscopic approaches have been described with favorable results.^2-5,8

The major benefits of arthroscopic treatment include decreased morbidity and improved cosmesis, although this method can be technically challenging.^2-5,8 Dr Millett ⁵ published a case series of 74 scapulae which had undergone arthroscopic treatment with a minimum 2-year follow-up. In this study, there was significant improvement in all outcome scores; however, 10.9% failed initial surgical management because of recurrent pain and underwent revision surgery. They found that greater age, lower preoperative psychological scores, and longer duration of symptoms before surgery correlated with lower postoperative outcome scores. This study concluded that arthroscopic surgery is an effective treatment for snapping scapula syndrome in both primary and revision cases as there was significant improvement in all postoperative outcome scores. ⁵

Dr Bradley, the senior author of this video, has experienced similar outcomes with his patients. We present here the case of a 21-year-old man with a 2-year history of painless but bothersome snapping of his scapula with range of motion of his left shoulder. He has trialed a physical therapy program without relief. His examination is positive for palpable crepitus of the superior medial border of the scapula with range of motion along with scapular dyskinesis. He has no winging or neurovascular abnormalities. Radiographs, including AP and scapular Y view are generally unremarkable, but a concern for prominence of the superior medial border of the scapula prompted the CT scan, which reveals an internal scapular angle of 50° and a prominence of the superior medial border of the scapula consistent with Luschka tubercle. The patient desired surgical resolution of this condition.

Therefore, we decided to proceed with scapulothoracic arthroscopy with bursectomy and resection of the superior medial border of the scapula. The patient is placed under general anesthesia and preoperative antibiotics are given. The patient is positioned prone on the operative table, and all bony prominences are well padded. The operative shoulder is propped up on a bump and is manipulated by an assistant during the case to open the scapulothoracic space; the arm is maximally internally rotated to elevate the superomedial border of the scapula from the thoracic wall.

The operative site is prepped and draped, including the entire operative extremity to allow for intraoperative manipulation. The scapulothoracic area is preinjected with local anesthetic and saline to expand the space and provide hemostasis. The borders of the scapula are marked and the incisions are localized. We use 2 portals to access the scapulothoracic joint. The superior portal is located 3 cm medial to the medial border of the scapula at the level of the scapula spine, the inferior portal is located 4 cm inferior to this. Placement of the portals, at least 3 cm medial to the medial border of the scapula, minimizes risk to the spinal accessory and dorsal scapular nerves.

The room setup consists of the operative surgeon standing on the opposite side of the patient with the arthroscopic tower positioned on the pathologic side. An assistant is positioned to manipulate the extremity and distract the scapulothoracic space. The portals are established with blunt dissection following skin incision. Pump pressures are regulated between 50 and 60 to allow for visualization without overdistension. We typically view from the inferior portal and instrument through the superior portal. This provides the most direct line for resection of the superior medial border of the scapula.

We begin with the 30° arthroscope through the inferior portal to visualize the under surface of the scapula. An arthroscopic shaver is used to perform a bursectomy to aid in visualization. Care is taken to avoid placing the shaver superolateral and risk injury to the suprascapular neurovascular bundle at the suprascapular notch. An electrocautery device is used to resect highly vascular tissue, including muscular attachments and the periosteum of the under surface of the scapula.

The superomedial border of the scapula is completely clear to muscular and bursal tissue with a shaver and electrocautery device. A shaver followed by an arthroscopic bur is then used to carefully resect the prominent superomedial border of the scapula.

The superomedial scapular resection is typically 3½ cm wide and 2½ cm deep.

Care should be taken to smoothly contour the resection with the arthroscopic bur so as to not cause any iatrogenic bony ridges.

A 70° arthroscope can then be used to evaluate the adequacy of the resection and identify areas of residual prominence.

We then use a measuring device to ensure an adequate resection.

In this case, our resection was 3 to 3½ cm wide and 1½ to 2 cm deep, corresponding with our preoperative plan.

Following resection, the scapulothoracic space is thoroughly irrigated, and all debris is removed. The portals are closed, and sterile dressing is applied. The postoperative plan consists of a sling for comfort for 24 hours. Passive range of motion is initiated at 24 hours. At 1 week, full range of motion and physical therapy are started. Physical therapy should focus on scapular control periscapular strengthening and postural retraining. Strength and exercises are continued until full function resumes around 4 weeks postoperatively. Return to sport is limited until 10 to 12 weeks postoperatively.

In closing, this slide highlights the senior author’s most important technical pearls to avoid complications with patient positioning and portal placement being the most critical aspects. After the patient is in the prone position, elevate the operative arm with a bump and maximally internally rotate to open the scapulothoracic space. Identify the relevant anatomy of the scapula including the superomedial border and the medial border of the scapula, as well as the scapular spine. Ensure that the superior working and inferior viewing portals are 3 cm medial to the medial border of the scapula to minimize risk to the neurovascular structures. Visualize the superomedial aspect of the scapula and confirm adequate bony resection which is typically 2 cm in depth and 3 to 3½ cm in width.

These are our references.