Rotating Around the Cuff of Shoulder Injuries

Shoulder injuries are a common yet complex presentation in emergency medicine, presenting a unique challenge due to the intricate anatomy and diverse range of potential pathologies, where imaging may not always be helpful. In this post, we will explore the various aspects of shoulder injuries from a clinical standpoint to help your bedside assessment; focusing on the rotator cuff, adhesive capsulitis, acromioclavicular joint injuries, clavicular fractures, and the utilization of shoulder injections in the emergency department. 

Shoulder Anatomy Review

The shoulder is an inherently unstable joint with a shallow glenoid fossa socket for the ball of the humeral head. The internal or static stabilizers of the joint include ligamentous complexes around the capsule consisting of the superior, middle, inferior, and spiral or transverse glenohumeral ligaments which attach to the labrum, which in turn is directly connected to the rim of the glenoid fossa. The labrum enlarges the diameter of that tee, the glenoid by close to 75%.

The external or dynamic stabilizers consist of the rotator cuff. Conceptually the function of the rotator cuff is to keep the humeral head in the glenoid fossa while allowing the arm to move freely.

Rotator Cuff

The interwoven nature of the rotator cuff tendons and muscular of the shoulder with their anatomical relationship to the capsule, ligaments, and bursa makes both the isolation of structures and the diagnosis of pathology extremely challenging with a high degree of variability. 

Supraspinatus

• Movement: abduction
• Testing:
  • Drop arm test (sp 90% for tear)
  • Resisted ER
  • Empty or full can test (Sn70% for tear)

Infraspinatus + Teres Minor

• Movement: External Rotation
• Testing:
  • External rotation lag sign/spring back sign (Sp 100% for tear)
  • Hornblower’s

Subscapularis

• Movement: internal Rotation
• Testing:
  • Lift-off Sign
  • Belly press
  • Bear hug

Rotator Cuff Injury Management

• Young pt with high suspicion for tear (weakness on testing):
  • Sling
  • Refer to Plaster Clinic
• Young pt with low suspicion for tear (pain without weakness):
  • Sling
  • Physio
  • Follow-up with sport med vs family MD
• Older pt with acute injury:
  • Sling
  • Physio
  • Follow-up with sport med vs family MD

Impingement

Narrowing of the subacromial space that causes pain. The exact pathophysiology of impingement is debated, likely multifactorial, and not the same for everyone. One cause could be from arthritic bony deformity narrowing the space. Another common mechanism purposed is an overuse injury and poor biomechanics causing tendinopathy and thickening of the supraspinatus tendon, which causes rotator cuff disfunction and migration of the humeral head into the subacromial space.

• Testing (cluster of three):
  • Painful arch (60-120 degrees of abduction)
  • Hawkins
  • Neer
• Management:
  • Activity medication
  • Analgesia – Tylenol, topical, consideration of injection
  • Physio
  • Consider sport medicine referral

Adhesive Capsulitis

An inflamed joint capsule becomes thick and stiff, develops adhesions, and decreases the amount of synovial fluid. Self-limiting disease course lasting 1-3 years.

• Risk factors:
  • Age 40-60
  • Women>men
  • Diabetes, thyroid disease, cardiac disease, Parkinson’s
• Three stages:
  • Freezing:
    • Pain increasing
    • Progressive loss of ROM (loosing ER first)
    • 6wks-9months
  • Frozen:
    • Minimal to no pain
    • No ROM
    • 4-6 months
  • Thawing:
    • Minimal to intermittent pain
    • ROM improving
    • 6months – 2 yrs
  • Management:
    • Diagnose + counsel on the expected course
    • Referral to sport medicine:
      • Freezing + frozen stages – cortisone +/- arthrodistension
    • Assisted ROM exercises at home
    • Physio for the thawing stage

Acromion clavicular joint injuries

• Mechanism: direct trauma to anterosuperior shoulder
• Testing (greatest diagnostic value with a combination of tests):
  • Palpation of joint (Sn96% Sp10%)
  • Cross body adduction (Sn77% Sp79%)
  • AC resisted extension (Sn72% Sp85%)
  • O’brien’s (Sn16% Sp90%)
  • Paxino (Sn79%)
• Dx on XR – Rockwood classification:

• Management:
  • Type I:
    • Sling (brief immobilization max 1 wk) – range the elbow 5x daily!
    • Early ROM -> strengthening with physio guidance
    • Return to play once non tender, full pain-free ROM – usually ~3wks
  • Type II:
    • Sling immobilization – range the elbow 5x daily!
    • Early ROM -> strengthening with physio guidance
    • Return to play once non tender, full pain-free ROM – usually ~6 wks
  • Type III-VI:
    • Sling immobilization
    • Refer to ortho – plaster clinic vs in ED (neurovascular compromise, open injuries, potential for skin breakdown)
    • Non-operative return to play in 6-12wks

Clavicle Fractures

• Mechanism: lateral shoulder trauma > direct clavicle trauma.
• XR view: upright AP or Zanca (15 degree cephalic tilt)
• Midshaft fractures are the most common (75-80% of clavicle fractures)
• Distal clavicle fractures classification:

• Management:
  • Consult ortho in the ED if:
    • Open fracture
    • Skin tenting
    • Floating shoulder (associated scapular neck fracture)
    • Neurovascular compromise
  • Midshaft fracture follow-up in plaster clinic if:
    • >2cm displaced
    • >2cm shortened
    • Seizure disorder
    • Brachial plexus injury
    • Athlete
  • Midshaft fracture without the above features:
    • Sling for pain control (1-2 wks)
    • Physio guided return to work and play:
      • 2wks ROM exercises
      • 6 wks begin strengthening
      • 4-6 months unrestricted return once full ROM and strength
    • Follow-up with family physician if possible
  • Distal clavicle fractures should ALL be referred to plaster clinic for follow-up due to the high rate of symptomatic non union.

Shoulder Injections:

Cortisone injections are for pain control that may last 3-6 months in hopes of getting them moving better and potentially participating in physiotherapy. Cortisone in the ED should not be injected into an area with an acute injury.

• Indications:
  • AC osteoarthritis
  • Glenohumeral osteoarthritis
  • Impingement
  • Adhesive capsulitis
  • Chronic tendinopathy without full tear of rotator cuff
• Contraindications:
  • Septic joint
  • Overlying cellulitis
  • Endocarditis
  • Osteochondral fracture
  • Joint prosthesis
  • Local anesthetic allergy
• Risks:
  • Pain flare (5-10% of pts)
  • Infection
  • Bleeding
  • Skin or fat atrophy
  • Nerve injury
  • Tendon rupture
  • Allergic reaction
  • Transient hyperglycemia
• Alternatives:
  • Analgesia
  • Hyaluronic acid injections
  • Possibly surgery

AC Joint Injection

• We can landmark the AC joint by finding the ends of the clavicle and acromion, using a sterile or no touch technique the needle should drop easily into the joint
• 20-40mg of steroid (0.5cc of volume) + 0.5cc of lidocaine

Subacromial Space/Bursa

• With sterile or no touch technique you will insert your needle roughly 1cm below posterior aspect of acromion border into the soft spot directing it superiorly and medially to target the underside of the acromion process. It should be easy to inject, if there is resist you are in likely in a tendon, reposition until it flows smoothly.
• 40-80mg of steroid (1-2cc of volume) + 1cc of lidocaine

Glenohumeral Joint

• To landmark guide this joint injection it is a similar approach to the subacromial space with locating the posterior border of the acromion process inserting the needle into the soft spot slightly more inferior but this time directing it anteriorly and medially towards the coracoid process. You are likely to hit or reach the humeral head, once you do, back out slightly and inject, again this should flow easily.
• 40-80mg of steroid (1-2cc of volume) + 1cc of lidocaine

Shoulder Dislocation; Post-Reduction Care

• (For more on dislocation management, click here)
• Post-reduction XR – true axillary or velpeau view
• Assess the rotator cuff – complete tears in young patients will be managed surgically
• Sling for comfort (1-2 weeks)
• Progressive ROM exercises
• Physio for strengthening and guiding return to play
• Refer to ortho/plaster clinic if:
  • Fracture
  • Recurrent dislocation
  • Athlete
  • Unsure of their stability/rotator cuff integrity
  • No one else to follow-up with

Click here for a Shoulder handout with ROM + strengthening exercises.