Common Flexor Tendon Injection

Other Names

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

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Background

Anatomy of the common flexor tendon

Key Points

• This page refers to injections of the Common Flexor Tendon
• The best approach is ultrasound guided, long-axis, in-plane

Anatomy

• Common Flexor Tendon
  • Composed of attachments of Pronator Teres (PT), Flexor Digitorum Superficialis (FDS), Flexor Carpi Ulnaris (FCU)
  • Common origin is the medial epicondyle of the distal humerus
  • Function is wrist flexion, forearm pronation

Palpation vs Ultrasound Guidance

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

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Indications

• Medial 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

Needle and probe position for long axis, in plane approach

Long-axis, in plane technique showing (A) ultrasound and needle position and (B) needle in plane

Probe and needle position for short axis, in plane technique

Short axis, in-plane approach of CFT injection anterior to posterior. Needle trajectory depicted by arrow, CFT (common flexor tenodn) and medial epicondyle (ME).

Needle and injection location marked for 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

• Common ultrasound findings include:
  • Cortical irregularities
  • Focal loss of visualization
  • Generalized hypoechogenicity
  • Thickening of the tendon
• Can compare to contralateral elbow

Ultrasound Guided: Long Axis, In-Plane

• Patient Position
  • The patient is seated or supine
  • The arm is externaly rotated, elbow in varying degrees of flexion
  • Medial compartment faces the proceduralist
• Probe Position and Needle Orientation
  • Transducer is in long axis to the common flexor tendon
  • Needle is in-plane, distal to proximal
  • Target is CFT and medial epicondyle
• Pearls and Pitfalls
  • Try to keep steroids superficial to the common flexor tendon

Ultrasound Guided: Short Axis, In-Plane

• Patient Position
  • The patient is seated or supine
  • The arm is externaly rotated, elbow in varying degrees of flexion
  • Medial compartment faces the proceduralist
• Probe Position and Needle Orientation
  • Transducer is in short axis to the common flexor tendon
  • Needle is in-plane, anterior to posterior
  • Target is superficial to the common extensor tendon at the interface of the lateral epicondyle
• Pearls and Pitfalls
  • Trauma to normal tissue may be reduced

Palpation Guided

• Patient Position
  • The patient is supine or seated
  • Arm is externally rotated, exposing the medial elbow
• 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 injecta

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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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