1) The correct answer is D.
According to the American College of Rheumatology's clinical criteria, hand osteoarthritis can be diagnosed if hand pain is accompanied by at least three of the following features:
- Hard tissue enlargement of 2 or more of 10 selected joints (second and third PIP and DIP as well as the first CMC joint of both hands)
- Hard tissue enlargement of 2 or more DIP joints
- Fewer than 3 swollen MCP joints
- Deformity of at least 1 of 10 selected joints
This classification method has a sensitivity of 94% and a specificity of 87%. Additional diagnostic testing is not warranted because it has no impact on disease management.
MRI can be used to detect soft tissue abnormalities such as tendonitis or early appearance of bony erosions but is not necessary to diagnose osteoarthritis.
Ultrasound-guided aspiration is useful to accurately obtain synovial fluid from small joints or in cases where the anatomy is obscure. In this patient, there is no evidence of effusion and so no need for attempted joint aspiration.
Serologic testing can be useful in the diagnosis of inflammatory arthritis such as rheumatoid arthritis, but in this patient with pain in the distribution of hand osteoarthritis and no alarm symptoms of inflammatory arthritis, is unnecessary.
Source: Altman R, Alarcón G, Appelrouth D, Bloch D, Borenstein D, Brandt K, et al. The American College of Rheumatology criteria for the classification and reporting of osteoarthritis of the hand. Arthritis Rheum 1990; 33:1601-10.
2) The correct answer is D.
These bony prominences at the DIP joints are commonly found on examination of the hands of patients with osteoarthritis. While Heberden's nodes may initially be associated with morning stiffness, erythema, and soft tissue swelling, this eventually subsides, leaving the patient with bony enlargement. Similar bony prominences at the PIP joints are known as Bouchard's nodes.
Tophi are deposits of monosodium urate crystals seen in people with high levels of serum uric acid, and are pathognomonic for gout. They can be seen at the joints but also in the soft tissue.
Boutonnière deformity refers to flexion of the PIP joint accompanied by hyperextension of the DIP joint. This can be seen in rheumatoid arthritis as well as other disease processes affecting the hands, such as tendon laceration, fracture, or dislocation.
Rheumatoid nodules are subcutaneous soft tissue swellings typically found over the elbows and fingers in patients with rheumatoid arthritis. Less commonly they can found in internal organs such as the lungs.
3) The correct answer is A.
Referral to an occupational therapist for splinting of the thumb. There are relatively few RCTs regarding interventions for hand OA in the literature. The American College of Rheumatology's 2012 recommendations for the use of non-pharmacologic and pharmacologic therapies in hand osteoarthritis suggests that splints for the first carpometacarpal (CMC) joint may alleviate some pain in patients with OA at the base of the thumb.
Wrist cock-up splints are typically used for carpal tunnel syndrome to relieve pressure on the median nerve as it passes through the carpal tunnel, which would not benefit thumb osteoarthritis.
There is limited evidence on intra-articular hyaluronic acid derivative injections in the first carpometacarpal joint and their use is not recommended.
Weekly low-dose oral methotrexate is used for the treatment of rheumatoid arthritis rather than osteoarthritis.
Source: Hochberg MC, Altman RD, April KT, et al., American College of Rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthritis Care Res. 2012 Apr;64(4):465-74.