Is a steroid injection a suitable treatment option for a patient with potential second metatarsophalangeal (MTP) joint issues?

Steroid Injection for Second Metatarsophalangeal Joint Issues

Intra-articular steroid injection is conditionally recommended for second metatarsophalangeal (MTP) joint issues when conservative treatments have failed, but should not be used as first-line therapy due to potential long-term risks.

Diagnostic Considerations Before Injection

Before considering steroid injection for second MTP joint issues:

1. Rule out contraindications:

   • Presence of intra-articular foreign body
   • Active infection
   • Fracture
   • Planned joint replacement surgery within 3 months 1, 2

2. Confirm diagnosis:

   • Complete imaging studies (X-ray, ultrasound, or MRI) to evaluate joint structure
   • Joint aspiration if infection is suspected
   • Assess for positive "Lachman" test of the MTP joint (indicating instability) 3

Treatment Algorithm

First-Line Treatments (Try before steroid injection)

• Oral NSAIDs on a scheduled basis 1
• Rocker-sole shoe modifications to limit MTP joint dorsiflexion 4
• Activity modification
• Physical therapy

Second-Line Treatment: Intra-articular Steroid Injection

When first-line treatments fail after 4-8 weeks:

1. Injection technique:

   • Strict aseptic technique is mandatory 5
   • Dosage: 2.5-5 mg triamcinolone for smaller joints like MTP 5
   • Consider aspiration if excessive synovial fluid is present 5

2. Post-injection care:

   • Avoid strenuous activity on the joint for 24 hours 2
   • Continue wearing appropriate footwear with rocker-sole modification

Efficacy and Risks

Efficacy

• Studies show 60% of MTP joint synovitis cases become asymptomatic and 33% show significant improvement with intra-articular steroid injection combined with footwear modification 4

Risks and Considerations

• Long-term joint health: Recent evidence suggests corticosteroid injections may accelerate cartilage loss and potentially increase the risk of requiring joint replacement in weight-bearing joints 6
• Temporary relief: Effects are time-limited without long-term improvement at 2-year follow-up 1
• Hammertoe deformity: 29% of MTP joints not initially associated with hammertoe may develop mild deformity after treatment 4

Special Considerations

• Skeletal maturity: In skeletally immature patients, intra-articular glucocorticoid injection is not recommended as first-line management 1
• Repeated injections: Should be avoided due to potential negative effects on bone health, joint structure, and cartilage thickness 1
• Monitoring: Follow up within 4-6 weeks after injection to assess response

When to Consider Surgery

Consider surgical consultation if:

• Persistent pain despite conservative treatment and steroid injection
• Progressive deformity (subluxation or dislocation)
• Significant functional limitation
• Advanced arthrosis on imaging 3

Steroid injection should be viewed as a temporary measure to provide symptom relief while addressing underlying biomechanical issues, rather than a definitive treatment for second MTP joint pathology.