First Metatarsophalangeal Joint Injection

Other Names

• Metatarsophalangeal Joint Injection
• 1st MTPJ Joint Injection
• Gout Injection
• Podagra Injection
• Metatarsophalangeal Joint Aspiration

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Background

Right

Demonstration of palpation guided approach (not recommended)

Key Points

• Transducer: high frequency, linear
• Needle: 25 gauage, 1.5 inch
• Dorsomedial approach is optimal
• Although you can inject/aspirate any joint, the 1st MTP joint is the most common by far

Anatomy of the Metatarsophalangeal Joint (MTPJ)

• Condyloid joint consisting of articulating of metatarsals and proximal phalanges
• Stabilizers: extensor tendons, lateral collateral ligaments, heavy plantar ligaments
• Plantar ligaments and metatarsal heads stabilized by deep transverse metatarsal ligaments
• At the first MTPJ, the two sesaamoid bones within the Flexor Hallucis Longus help stabilize the Plantar Plate
• Movements are primarily flexion/extension, limited abduction/adduction

Palpation Guidance vs Ultrasound Guidance

• Palpation guided injection of the 1st MTPJ has been described
• Ultrasound guidance has been shown to have a success rate of 100%
• Balint et al showed US guided aspiratoin was 97% while landmark guided aspiration was only 32%
• Raza et al found 96% accuracy with US guided injections, 59% accuracy with palpation guided injections

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Indications

• Gout
• Recalcitrant MTPJ pain

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Contraindications

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

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Procedure

Out-of-plane, medial-to-lateral needle approach to first (MTP) metatarsophalangeal joint.

Long-axis imaging over the first metatarsophalangeal joint shows the metatarsal head (open arrow), metatarsophalangeal (MTP) joint space (asterisk), and proximal phalanx (thin arrow)

n-plane, proximal to distal needle approach to first metatarsophalangeal joint.

63-year-old male diagnosed presenting recently with 5 days’ history of 1st MTP joint pain, for steroid injection. a, b Graphic illustration (a) and long-axis US image (b) demonstrate insertion of the needle (arrows in B) from a proximal to distal direction using a long-axis, in-plane approach (PP = proximal phalanx; MT = metatarsal)

Equipment

• Sterile prep (i.e. chloraprep, chlorhexidine, iodine, etc)
• Gloves
• Needle: typically 21-25 gauge, 1.5 inch
• Syringe: 5-10 mL
• Gauze
• Ethyl Chloride
• Bandage
• Injectate
  • Local anesthetic
  • Corticosteroid
• Sterile probe cover

Ultrasound Findings

• Best visualized in long axis
• Common findings
  • Cortical irregularities
  • Joint space narrowing
  • Osteophytes and calcifications
  • Synovial hypertrophy
  • Joint effusion

Ultrasound Guided Technique: Long Axis, Out of Plane

• Patient Position
  • The patient is supine
  • Foot flat on table with knee flexed
• Transducer Position
  • Dorsomedial to the MTPJ of interest
  • Anatomic, sagittal/ long axis to the joint
• Needle Approach/ Orientation
  • Out of plane
  • Lateral to medial or medial to lateral using a step-wise approach
• Target
  • Dorsomedial aspect of the MTP joint
• Pearls and Pitfalls
  • Dorsal approach helps avoid the medial/lateral digital nerves
  • Avoid the extensor tendons

Ultrasound Guided Technique: Long Axis, In Plane

• Patient Position
  • The patient is supine
  • Foot flat on table with knee flexed
• Transducer Position
  • Dorsomedial to the MTPJ of interest
  • Anatomic, sagittal/ long axis to the joint
• Needle Approach/ Orientation
  • Out of plane
  • Proximal to distal
• Target
  • Dorsomedial aspect of the MTP joint
• Pearls and Pitfalls
  • Dorsal approach helps avoid the medial/lateral digital nerves
  • Technically more difficult than the short axis approach

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Aftercare

• Motor exam should be intact
• No major restrictions in most cases
• Can augment with ice, NSAIDS

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Complications

• Infection
• Damage to surrounding tissue

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See Also

Internal

• Procedures Main
• Ultrasound Main
• Ankle Pain Main

External

• https://www.sportsmedreview.com/blog/performing-an-ultrasound-guided-first-mtp-joint-injection/

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