Common Extensor Tendon Injection

Other Names

• Common Extensor Tendon Peritendinous Injection
• Tennis Elbow Injection
• Common Extensor Tendon Injection

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Background

Illustration of the 4 muscles of the common extensor tendon

Key Points

• The most common extensor tendinopathy occurs in the extensor carpi radialis brevis tendon, deep to extensor digitorum
• The recommended and optimal approach is ultrasound guided long axis, in-plane
• Although corticosteroids have been used historically, this is typically more of a degenerative process than an inflammatory one

Anatomy

• Common Extensor Tendon
  • Composed of extensor carpi radialis brevis, extensor digitorum communis, extensor digiti minimi, extensor carpi ulnaris
  • Common origination at the lateral epicondyle of the distal humerus
  • ECRB tendon is most anterior
  • Function is wrist extension, radial/ulnar abduction

Palpation vs Ultrasound Guidance

• To date, there are no studies comparing ultrasound-guided and palpation-guided approaches

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Indications

• Lateral Epicondylitis

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Contraindications

• Absolute
  • Anaphylaxis to injectates
  • Overlying cellulitis, skin lesion or systemic infection
• Relative
  • Can be treated with less invasive means
  • Tendon tear or rupture
  • Hyperglycemia or poorly controlled diabetes
  • Lack of symptom improvement with previous injection

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Procedure

Transducer and needle position for long axis, in-plane approach

Long axis, in-plane view from distal to proximal. Arrow indicates needle tract in the peritendinous region. CET (common extensor tendon), LE (lateral epicondyle), RCJ (radiocapitellar joint)

Transducer and needle position for short axis, in-plane approach

Short axis, in-plane view from lateral to medial. Arrow indicates needle tract in the peritendinous region. CET (common extensor tendon), LE (lateral epicondyle)

Picture of palpation guided approach

Equipment

• Sterile including chloraprep, chlorhexadine, iodine
• Ultrasound with sterile probe cover
• Gloves
• Needle: typically 21-25 gauge, 1.5 inch
• Syringe: 5-10 mL
• Gauze
• Ethyl Chloride
• Bandage
• Injectate
  • Local anesthetic
  • Corticosteroid/ injectate

Ultrasound Findings

• Best visualized with a high frequency linear probe
• Depth is usually 2 to 3 cm
• Examine the tendon in long and short axis
• Common ultrasound findings include:
  • Cortical irregularities
  • Focal loss of visualization
  • Generalized hypoechogenicity
  • Thickening of the tendon
• Consider comparison to the contralateral/ unaffected elbow

Ultrasound Guided: Long Axis, In-Plane

• Patient Position
  • The patient is seated or supine
  • The arm is wresting in a neutral position, elbow flexed to 90°, wrist pronated
  • Lateral compartment faces the proceduralist
• Probe Position and Needle Orientation
  • Transducer is in long axis to the common extensor tendon
  • Needle is in-plane, distal to proximal
  • Target is superficial to the common extensor tendon at the interface of the lateral epicondyle
• Pearls and Pitfalls
  • Try to keep steroids superficial to the common extensor tendon

Ultrasound Guided: Short Axis, In-Plane

• Patient Position
  • The patient is seated or supine
  • The arm is wresting in a neutral position, elbow flexed to 90°, wrist pronated
  • Lateral compartment faces the proceduralist
• Probe Position and Needle Orientation
  • Transducer is in short axis to the common extensor tendon
  • Needle is in-plane, lateral to medial
  • Target is superficial to the common extensor tendon at the interface of the lateral epicondyle
• Pearls and Pitfalls
  • Try to keep steroids superficial to the common extensor tendon

Palpation Guided

• Patient Position
  • The arm is wresting in a neutral position, elbow flexed to 90°, wrist pronated
• Landmarks
  • Palpate the lateral epicondyle and identify the center
  • The point of maximal tenderness may be useful
• Procedure
  • Advance the needle either perpendicular to the skin or at a 45°
  • The depth is typically betwenen 0.5 and 1.5 cm
  • If resistance is met, the needle is too deep and within the body of the tendon
  • Inject slowly while withdrawing slowly until flow of the injectate is easy
  • This suggests the needle is now in the peritendinous area

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Aftercare

• No major restrictions in most cases
• Can augment with ice, NSAIDS

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Complications

• Skin: Subcutaneus fat atrophy, skin atrophy, skin depigmentation
• Painful local reaction
• Infection
• Hyperglycmia
• Tendon, nerve or blood vessel injury
• Tendon rupture
  • Frequency unknown
  • Using ultrasound guidance, the tendon should never be injected

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See Also

• Procedures Main
• Ultrasound Main
• Elbow Pain Main

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