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Basics ⬇

Author(s): AndrewCheung, DO and Mark E.Lavallee, MD, CSCS, FACSM

Description

  • Repetitive shoulder activity causes breakdown in the rotator cuff muscles from tensile overload and results in tendinopathy.
  • Weakness in the rotator cuff muscles (supraspinatus, infraspinatus, teres minor, or subscapularis) results in loss of effective dynamic glenohumeral movement.
  • This causes impingement of the cuff muscles under the acromion, enhancing the pain and inflammation.
  • Synonym(s): subacromial bursitis; shoulder impingement syndrome

Epidemiology

  • Very common in athletes, especially in those with repetitive motion of the arms (i.e., throwing, racquet sports, swimming, weight lifting)
  • In individuals <25 yr of age, impingement is usually related to laxity caused by instability.
  • In those 25 to 40 yr of age, impingement is usually due to overuse of the rotator cuff.
  • In those >40 yr of age, impingement is caused by use of the cuff muscles over threshold. This may result in partial- or full-thickness tears in addition to impingement.

Risk-Factors

  • Weight lifting (Olympic style) and CrossFit
  • Throwing or racquet sports
  • “Industrial” athletics (repetitive, overhead motion)
  • Shoulder instability
  • Previous shoulder surgery or trauma (to ipsilateral or contralateral shoulder)
  • Individuals with more “hooked” acromial morphology (type III > type II > type I)
  • Smoking
  • Diabetes

Commonly Associated Conditions

Diagnosis ⬆ ⬇

History

  • Rule out cervical spine disease, neck pain.
  • Symptoms: weakness, crepitation, numbness, “slipped out,” night pain, dead arm
  • Exacerbation: Pain presents more at rest or with activity.
  • Duration: chronic (overuse) versus acute (traumatic)
  • Activation: right or left handed, type of job, sports, hobby
  • History of previous trauma or surgery

Physical Exam

  • Shoulder pain with overhead activity
  • Weakness in the shoulder musculature
  • Crepitus
  • Numbness/paresthesias (usually between the lateral neck to the elbow)
  • Night pain
  • Pain at rest (usually in more severe cases)
  • Medial upper scapular border or medial upper trapezius pain
  • Observation:
    • How the athlete carries arm/shoulder (e.g., recent dislocation, guarding, obvious asymmetry)
    • Deltoid atrophy (i.e., C5 plexus injury)
    • Scapular winging (i.e., long thoracic nerve palsy, cranial nerve XI palsy)
    • Infraspinatus fossa scalloping (inferior branch of the suprascapular nerve)
  • Palpation:
    • Cervical spinous process: Rule out cervical neck pathology as cause of shoulder pain.
    • Subacromial bursa: distal to acromion
    • Biceps tendon (long head)/bicipital groove
    • Insertion of the deltoid on the humerus: pain at site but no pain with palpation; axillary nerve pain referral site
    • Coracoid process: pain referral site for impingement
  • Range of motion (ROM):
    • Abduction (0 to 180 degrees)
    • Adduction (0 to 50 degrees)
    • Flexion: forward (0 to 180 degrees) and horizontal (0 to 130 degrees)
    • Extension (0 to 90 degrees)
    • Internal rotation (0 to 100 degrees) (adduction and internal rotation: “bra strap”)
    • External rotation (0 to 60 degrees) (abduction and external rotation: “shampoo hair”)
  • Manual muscle testing:
    • Deltoid: full abduction, resist at 90 degrees
    • Supraspinatus: abduction to 90 degrees forward flexion to 30 degrees, resist downward pressure (empty can/Jobe test)
    • Infraspinatus and teres minor: arm at side, 90 degrees at elbow, resist external rotation (i.e., “opening the door”)
    • Subscapularis: hand on lower back, push against resistance; Gerber lift-off test
  • Special tests:
    • Hawkins test: 90 degrees of forward flexion at the shoulder and elbow, support elbow, pain with internal rotation of arm
    • Arc test: Shoulder abduction gets “stuck” or painful at 60 to 120 degrees.
    • Infraspinatus test: 90 degrees of flexion at the elbow; elbow held against body while patient attempts to externally rotate arm against examiner’s resistance, pain in shoulder with external rotation
    • Neer test: arm straight, thumb down, passive forward flexion (pain at 60 to 120 degrees)
    • Impingement test: Inject subacromial bursa with lidocaine; helps to differentiate between impingement and tear; after injection, pain, ROM, and strength should improve if impingement and not a tear.
    • Drop arm test: Patient cannot hold arm at 90 degrees of abduction; indicates cuff tear
    • Speed test: arm straight, forward flexion to 90 degrees, palm up, resisted downward pressure; palpate the bicipital tendon at groove; pain indicates bicipital tendonitis.

Differential Diagnosis

  • Rotator cuff tear (partial or full thickness)
  • Adhesive capsulitis
  • Acromioclavicular sprain/injury
  • Labral tear
  • Bicipital tendonitis
  • Thoracic outlet syndrome
  • Brachial plexus injury
  • Fracture: clavicle, humerus, scapula
  • Subluxation of glenohumeral joint
  • Axillary nerve entrapment
  • Pancoast tumor
  • Bankart lesion (avulsion fracture of glenoid labrum)
  • Hill-Sachs lesion (impact fracture of humeral head)
  • Septic arthritis
  • Glenohumeral arthritis
  • Thrombosis of subclavian or brachial artery

Diagnostic Tests & Interpretation

  • Imaging is often not needed in light of good history and physical exam and a straightforward case.
  • Radiography (1,2):
    • Anteroposterior (AP) view and axillary (transscapular) views bare minimum to order; radiographs helpful for acute injuries to rule out fractures, dislocations; with impingement, may be helpful to get additional views
    • Internal and external AP rotational views help to visualize humerus (i.e., Hill-Sachs lesions).
    • Stryker notch view helps to visualize posterolateral humeral head deformity (i.e., Hill-Sachs lesions).
    • West Point (modified axillary) view allows visualization of the anterior/inferior glenoid (i.e., Bankart lesions).
    • Outlet or Alexander view allows for visualization of subacromial space; helpful in elderly patients with severe impingement
    • Calcification on the tendon is associated with bicipital tendonitis or severe impingement.
  • Ultrasound (US) (3):
    • Dependent on skill and comfort of practitioner, can be cost-effective in-office imaging choice for static and dynamic view of soft tissue structures of the shoulder (i.e., rotator cuff muscles, biceps tendons, subacromial bursa, calcification in tendons)
    • Also, can be used to guide injections into biceps tendon sheath, subacromial bursa, or intra-articular area
  • Magnetic resonance imaging (MRI):
    • In severe or confusing cases, MRI is helpful in diagnosis of rotator cuff tears, labrum tears, biceps tendon rupture as well as assessing volume and capsule thickening in adhesive capsulitis (1).
    • An MRI arthrogram is often useful to further displace a torn labrum, thus improving visualization of the anatomy.
  • Electromyography/nerve conduction study: helpful if there is weakness in addition to an altered neurologic exam (sensation, reflexes); has the highest sensitivity when symptoms have persisted >3 wk

Treatment ⬆ ⬇

Medication

  • Oral analgesia: nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, tramadol; in severe cases, short-term pain relief with narcotics. Prednisone: short course of 40 mg daily for 5 days
  • Dermal: topical cream or transdermal patches (NSAID or lidocaine based)
  • Injectable: subacromial bursa injection (5 to 10 mL 2:2:1 mixture of lidocaine/bupivacaine, corticosteroid; use a 22- to 25-gauge, 1.5-inch-long needle)

Additional Therapies

  • Management of acute phase (4):
    • Relative rest: Decrease use of affected shoulder.
    • Home exercise program (HEP): exercise done daily, three sets per exercise
    • ROM: dangling arm circles, finger wall-walking, broom-handle exercises
    • Strengthening: sword-from-sheath exercises, posterior dumbbell raises, proprioceptive neuromuscular facilitation (PNF), augmented soft tissue mobilization (ASTM), scapular stabilizing exercises using light weights or flexible elastic cords
  • Rehabilitation for long-term treatment:
    • Formal physical therapy: pain relief via contrast baths, hydrocollator, ice, mobilization/manipulation, modalities (e.g., electrostimulation, US therapy)
    • ROM strengthening: deltoid, rotator cuff musculature, scapular stabilizers, biceps
    • ROM flexibility: biceps, triceps, glenohumeral joint
    • Transmembrane corticosteroid (i.e., phonophoresis, iontophoresis)
    • Return to normal function.
    • Sports-specific retraining
  • In the younger athlete, impingement is often due to another underlying problem (i.e., instability, scapular dyskinesis [5], muscular imbalance).
  • Certain athletes (i.e., mentally challenged, unmotivated, etc.) may need assistance of formal physical therapy without a trial of HEP.

Surgery/Other Procedures

  • Anterior acromioplasty: The acromion is “shaved” to allow more space for the rotator cuff. It is used only if conservative measures fail. There is a less favorable outcome in younger (50% success rate) than older athletes.
  • Surgical débridement/repair of rotator cuff: often accompanies an anterior acromioplasty
  • Surgical débridement/repair of labrum

COMPLEMENTARY & ALTERNATIVE MEDICINE

Mentioned in literature for recalcitrant cases: prolotherapy, platelet-rich plasma (PRP) injections, acupuncture, dry needling, autologous stem cell therapy, and topical nitrates

Ongoing Care ⬆ ⬇

Follow-up Recommendations

  • Presence of a fever and a tense joint capsule (i.e., a potentially septic joint, orthopedic surgical emergency)
  • Severe disease that is refractory to physical therapy, modalities, and steroid injections
  • Rotator cuff tear, full or partial thickness, nonresponsive to conservative care
  • Cervical rib, causing shoulder symptoms
  • superior labrum anterior and posterior (SLAP)
  • Gross instability of shoulder not improved with physical therapy

Additional Reading ⬆ ⬇

Monica J, Vredenburgh Z, Korsh J, et al. Acute shoulder injuries in adults. Am Fam Physician. 2016;94(2):119–127.

References ⬆ ⬇

  1. Corpus KT, Camp CL, Dines DM, et al. Evaluation and treatment of internal impingement of the shoulder in overhead athletes. World J Orthop. 2016;7(12):776–784.
  2. Parker B, Zlatkin M, Newman J, et al. Imaging of shoulder injuries in sports medicine: current protocols and concepts. Clin Sports Med. 2008;27(4):579–606.
  3. Iannotti JP, Ciccone J, Buss DD, et al. Accuracy of office-based ultrasonography of the shoulder for the diagnosis of rotator cuff tears. J Bone Joint Surg Am. 2005;87(6):1305–1311.
  4. Steuri R, Sattelmayer M, Elsig S, et al. Effectiveness of conservative interventions including exercise, manual therapy and medical management in adults with shoulder impingement: a systematic review and meta-analysis of RCTs. Br J Sports Med. 2017;51(18):1340–1347.
  5. Burn MB, McCulloch PC, Lintner DM, et al. Prevalence of scapular dyskinesis in overhead and nonoverhead athletes: a systematic review. Orthop J Sports Med. 2016;4(2):2325967115627608.

Clinical Pearls ⬆

  • If caught early with no other shoulder pathology and treated with aggressive conservative therapy, many athletes are able to return to their prior level of competition.
  • With subacromial injections, often pain relief is immediate, due to the analgesia (i.e., lidocaine/bupivacaine). This will wear off. Corticosteroid injections may have a delay in onset of up to 3 days.
  • If no other shoulder pathology is present, and the injury is treated with aggressive conservative therapy, most athletes respond well and are able to avoid surgery.