Chapter 16

Arthroscopic Treatment of Scapulothoracic Disorders

Michael J. Huang and Peter J. Millett

DEFINITION

• Several terms have been used to describe the elements of scapulothoracic bursitis and crepitus, such as snapping scapula, washboard syndrome, scapulothoracic syndrome, and rolling scapula.

• The first description of scapulothoracic crepitus is credited to Boinet in 1867.1

• By 1904, Mauclaire5 had described three subclasses— froissement, frottement, and craquement—depending on the loudness and character of the sound.

• Milch6 and then Kuhn et al4 added to the understanding by differentiating sounds of soft tissues (frottement) from those arising from an osseous lesion (craquement or crepitus).

  ANATOMY

• Major bursae

  • Infraserratus bursa located between the serratus anterior muscle and the chest wall

  • Supraserratus bursa located between the subscapularis and the serratus anterior muscles

• Minor bursae

  • Not consistently identified on cadaveric or clinical studies

  • Adventitial in nature; thought to arise secondary to abnormal biomechanics of the scapulothoracic joint

  • Superomedial angle of the scapula

    • Infraserratus

    • Supraserratus

  • Spine of scapula

    • Trapezoid

  • Inferior angle of scapula

    • Infraserratus

      PATHOGENESIS

• Scapulothoracic bursitis can be caused by atrophied or fibrotic muscle, anomalous muscle insertions, or elastofibroma (rare benign soft tissue tumor located on the chest wall).

• Osteochondromas and malunited fractures of the ribs or scapula can also cause pathology in this articulation.

• Infectious causes include tuberculosis or syphilis.

• The tubercle of Luschka is a prominence at the superomedial aspect of the scapula that can be excessively hooked and can cause altered biomechanics.

• Scoliosis or thoracic kyphosis can contribute to scapulothoracic crepitus.

• Unrelated disorders include cervical radiculopathy, glenohumeral pathology, and periscapular strain.

  NATURAL HISTORY

• Scapulothoracic disorders are often associated with repetitive overhead activities or with a history of trauma.

• Constant motion leads to inflammation and a cycle of chronic bursitis and scarring.

   

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• Mechanical impingement and pain with motion are a result of tough fibrotic tissue, furthering the inflammatory cycle.

  PATIENT HISTORY AND PHYSICAL FINDINGS

• Repetitive overhead activities or trauma

• Palpable or audible crepitus over the involved area

• Occasionally bilateral or positive family history

• Localized tenderness over the inflamed area is most common.

  • Superomedial border is the most commonly affected area.

  • Inferior pole is also a common site of pathology.

• Pseudowinging (nonneurologic etiology) may result from fullness over the involved area and compensation of scapular mechanics due to pain.

• Crepitus alone, without pain, may be physiologic and not warrant treatment.

  IMAGING AND OTHER DIAGNOSTIC STUDIES

• Tangential scapular views to identify bony anomalies

• Computed tomography is controversial but can be helpful if osseous lesions are suspected and plain radiographs are normal.

• Magnetic resonance imaging (MRI) is also controversial but can identify the size and location of bursal inflammation.

• Injection of a corticosteroid and local anesthetic is helpful to confirm the diagnosis.

  DIFFERENTIAL DIAGNOSIS

• Atrophied, fibrotic muscle or anomalous muscle

• Malunited rib or scapular fracture

• Mass (eg, elastofibroma, osteochondroma)

• Infection (ie, tuberculosis, syphilis)

• Scoliosis or kyphosis

• Cervical spine radiculopathy

• Glenohumeral disease

  NONOPERATIVE MANAGEMENT

• Rest

• Nonsteroidal anti-inflammatory

• Activity modification

• Physical therapy

  • Local modalities

  • Periscapular strengthening, emphasizing subscapularis and serratus anterior

  • Postural training

• Figure 8 harness for kyphosis

• Injection may be of benefit for both diagnosis and treatment.

  SURGICAL MANAGEMENT

• Indicated for patients who have failed to respond to conservative therapy

• Open treatment

   

   

   

  Chapter 16 ARTHROSCOPIC TREATMENT OF SCAPULOTHORACIC DISORDERS 135

   

   

   

   

  FIG 1 • The arm behind the back in extension and internal rotation: the “chicken wing” position.

  • Has been used successfully in treatment of both bursitis7,9 and crepitus6,8

  • Requires fairly large exposure and subperiosteal dissection of the medial musculature, with repair back to bone after débridement of pathologic tissue is accomplished

• Arthroscopic treatment

  • Minimizes morbidity of the exposure and facilitates early rehabilitation and return to function

    Preoperative Planning

• If a bony mass is detected, computed tomography findings will help guide the planned resection.

Positioning

• The patient is placed in the prone position, with the arm behind the back in extension and internal rotation (the so-called chicken wing position; FIG 1).

  Approach

• Decisions regarding open versus arthroscopic treatment for these disorders should be based on surgeon experience and comfort level.

  POSTOPERATIVE CARE

• Sling for comfort

• Gentle passive motion immediately

• Active and active-assisted motion and isometric exercises are started at 4 weeks postoperatively.

• Periscapular strengthening starts at 8 weeks postoperatively.

  OUTCOMES

• No large series of arthroscopic treatment have been published.

• Several smaller series have reported favorable outcomes after arthroscopic surgery.2,3

  COMPLICATIONS

• Pneumothorax

• Infection

• Inadequate resection, recurrence of symptoms

   

   

  ARTHROSCOPIC PORTALS

  • The initial “safe” portal is 2 cm medial to the medial scapular edge at the level of the scapular spine, between the chest wall and serratus anterior (TECH FIG 1A).

    • Avoids dorsal scapular nerve and artery

    • The space is distended with 150 mL saline via spinal needle and then the portal is created.

  • After insertion of a 4.0-mm 30-degree arthroscope into the first portal, a second “working” portal is established under direct visualization (TECH FIGS 1B and 1D).

     

  • It is placed about 4 cm inferior to the first portal.

    TECHNIQUES

     

  • A 6-mm cannula is inserted into this portal.

• An additional superior portal can be placed as described by Chan et al1 (TECH FIG 1C).

  • Portals superior to the scapular spine place the dorsal scapular neurovascular structures, accessory spinal nerve, and transverse cervical artery at risk, however.

A B C

TECH FIG 1 • Placement of the first arthroscopic portal (A), the second “working” arthroscopic portal (B), and the optional superior portal (C).

D D. Arthroscopic view from the first portal.

136 Part 1 SPORTS MEDICINE • Section I SHOULDER

TECHNIQUES

RESECTION

• A methodical approach to resection is needed because there are minimal anatomic landmarks.

• Radiofrequency ablation and motorized shaving are used (TECH FIG 2A,B).

• The surgeon proceeds medial to lateral and inferior to superior.

• Spinal needles can be used to outline the medial border of the scapula (TECH FIG 2C,D).

• Switching portals and the use of a 70-degree arthroscope may be necessary (TECH FIG 2E,F).

   

• The superomedial angle of the scapula is identified by palpation through the skin.

• Radiofrequency is used to detach the conjoined insertion of the rhomboids, levator scapulae, and supraspinatus from the bone.

• A partial scapulectomy is performed using a motorized shaver and burr.

• The arm should then be placed through a range of motion to assess the resection.

A B

C D

TECH FIG 2 • A,B. Resection and débridement of the scapula. C,D. The spinal needle is used as a guide to the medial border of the scapula. E,F. Final

E F débridement.

PEARLS AND PITFALLS

Portal placement

Visualization

Bursectomy

Partial scapulectomy

• The surgeon should consider the neurovascular structures and the thoracic structures.

• The surgeon should enter parallel to the ribs and use a spinal needle to localize the portals.

• More inferiorly placed portals are safer because the dorsal scapular nerve arborizes terminally.

• Predistention

• Epinephrine for vasoconstriction

• Appropriate pump pressure

• The surgeon should work expeditiously.

• Inadvertent thoracotomy is avoided.

• A complete bursectomy is performed.

• The surgeon should avoid perforating the subscapularis muscle medially (bleeding).

• Preoperative planning with computed tomography or three-dimensional computed tomography

• Anatomy is localized with a spinal needle.

• Adequate resection is performed.

Chapter 16 ARTHROSCOPIC TREATMENT OF SCAPULOTHORACIC DISORDERS 137

REFERENCES

1. Chan BK, Chakrabarti AJ, Bell SN. An alternative portal for scapulothoracic arthroscopy. J Shoulder Elbow Surg 2002;11:235–238.

2. Ciullo J, Jones E. Subscapular bursitis: conservative and endoscopic treatment of “snapping scapula” or “washboard syndrome.” Orthop Trans 1993;16:740.

3. Harper GD, McIlroy S, Bayley JI, et al. Arthroscopic partial resection of the scapula for snapping scapula: a new technique. J Shoulder Elbow Surg 1999;8:53–57.

4. Kuhn JE, Plancher KD, Hawkins RJ. Symptomatic scapulothoracic crepitus and bursitis. J Am Acad Orthop Surg 1998;6:267–273.

    

5. Mauclaire M. Craquements sous-scapulaires pathologiques traits par l’interposition musculaire interscapulothoracique. Bull Mem Soc Chir Paris 1904;30:164–168.

6. Milch H. Partial scapulectomy for snapping of the scapula. J Bone Joint Surg Am 1950;32A:561–566.

7. Nicholson GP, Duckworth MA. Scapulothoracic bursectomy for snapping scapula syndrome. J Shoulder Elbow Surg 2002;11:80–85.

8. Richards RR, McKee MD. Treatment of painful scapulothoracic crepitus by resection of the superomedial angle of the scapula: a report of three cases. Clin Orthop Relat Res 1989;247:111–116.

9. Sisto DJ, Jobe FW. The operative treatment of scapulothoracic bursitis in professional pitchers. Am J Sports Med 1986;14:192–194.