From the Guidelines
For suspected synovitis of the first metatarsophalangeal (MTP) joint and interphalangeal joint, I strongly recommend a thorough evaluation to rule out underlying conditions such as rheumatoid arthritis (RA), using the 2010 ACR/EULAR Classification Criteria for Rheumatoid Arthritis as a guideline 1. When evaluating a patient with suspected synovitis, it is crucial to consider the criteria for joint involvement, serologic findings, acute phase reactants, and duration of symptoms to determine the likelihood of RA or other conditions.
- The 2010 ACR/EULAR Classification Criteria for Rheumatoid Arthritis provide a score-based algorithm to classify RA, with a score of 6/10 or higher indicating definite RA 1.
- Joint involvement is assessed based on the number and location of swollen or tender joints, with small joints such as the metacarpophalangeal joints, proximal interphalangeal joints, and second through fifth metatarsophalangeal joints being more indicative of RA than large joints 1.
- Serologic findings, including rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA), can also support a diagnosis of RA, with high positive results being more indicative of the disease than low positive or negative results 1.
- Acute phase reactants, such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), can also be elevated in RA, and their levels can be used to support a diagnosis 1.
- The duration of symptoms is also an important consideration, with symptoms lasting 6 weeks or longer being more indicative of RA than shorter durations 1. In terms of treatment, a combination of rest, anti-inflammatory medication, and appropriate footwear is recommended, with oral NSAIDs such as ibuprofen 400-600mg three times daily with food for 7-10 days, or naproxen 500mg twice daily, being a reasonable starting point.
- Applying ice to the affected area for 15-20 minutes several times daily can help reduce inflammation, and rest and avoiding activities that exacerbate pain can also help alleviate symptoms.
- Wearing wide, supportive shoes with a stiff sole can minimize joint movement and reduce pressure on the inflamed joints, and using a metatarsal pad or orthotic insert can redistribute pressure away from the painful area. If symptoms persist beyond 2 weeks despite these measures, seeking medical evaluation for potential corticosteroid injections, such as methylprednisolone 40mg mixed with lidocaine, may be necessary.
- Physical therapy focusing on gentle range of motion exercises can help maintain joint mobility once acute inflammation subsides. It is essential to note that synovitis can be a precursor to conditions like hallux rigidus or may be associated with conditions like gout, RA, or osteoarthritis, which may require additional specific treatments if identified.
From the Research
Suspected Synovitis of the 1st MTP Joint and Interphalangeal Joint
- The 1st MTP joint is a common site for synovitis, with various studies investigating its diagnosis and treatment 2, 3, 4, 5, 6.
- Synovitis of the 1st MTP joint can be caused by various factors, including osteoarthritis, rheumatoid arthritis, and pigmented villonodular synovitis (PVNS) 2, 3, 6.
- Diagnosis of synovitis of the 1st MTP joint can be made using various imaging modalities, including ultrasonography and magnetic resonance imaging (MRI) 5, 6.
- Treatment options for synovitis of the 1st MTP joint include nonoperative management, such as intra-articular corticosteroid injections and orthoses, as well as surgical excision in cases of PVNS 2, 3, 4.
Imaging Modalities
- Ultrasonography is a valuable tool for diagnosing synovitis of the small joints, including the 1st MTP joint, and can be accurately performed by rheumatologists with minimal experience 5.
- MRI is also a useful imaging modality for characterizing the pathology of 1st MTP joint osteoarthritis, and can help identify characteristic features such as osteophytes, bone marrow lesions, and cartilage loss 6.
Treatment Options
- Nonoperative management of 1st MTP joint synovitis can be effective, with a study showing that 60% of patients were asymptomatic at follow-up evaluation 2.
- Surgical excision is a treatment option for PVNS of the 1st MTP joint, but may require repeat procedures in cases of recurrence 3.
- Podiatrists and physical therapists use a range of assessment and treatment approaches for 1st MTP joint osteoarthritis, including orthoses, exercise therapy, and medication, although the evidence for their clinical utility is limited 4.