CASE 1
1) The most characteristic clinical complaints for OA of the hands are the short duration of morning stiffness, and the distribution of joints involved: the distal finger joints and base of the thumb, with sparing of the MCPs.
2) The key distinguishing feature of OA is the lack of synovitis. Bony joint enlargement is characteristic of OA. The distribution again is more characteristic of OA than rheumatoid arthritis (RA).
3) Radiographs were not necessary in order to make the diagnosis. Joint space narrowing with osteophyte formation is characteristic for OA.
4) No laboratory studies are indicated for making a diagnosis of OA, unless other diagnoses are in your differential. Baseline laboratory measurement of blood counts, and liver and kidney function should be considered depending on what medications are instituted as therapy.
The patient is begun on daily acetaminophen and referred to occupational therapy for evaluation both for hand exercise and adaptive equipment. She is also given a splint for the carpometacarpal joint of the thumb of the dominant hand.
5) Other oral medications that could be tried include non-steroidal anti-inflammatory drugs (NSAIDs) and pain medications. Some patients respond to local injections to the thumb joints. Rarely is surgical intervention warranted.
CASE 2
1) Secondary osteoarthritis is dominant in the differential. Other considerations would include infection, crystal disease and active RA.
2) Joint aspiration of the involved knee for fluid analysis would be the most helpful.
- Sterile joint aspiration of the right knee is performed and 35 cc of yellow fluid is obtained. Analysis of the fluid demonstrates a white blood cell (wbc) count of 750/cu mm and only 50 rbc/cu mm. Crystal examination, gram stain and culture are all negative. Radiographs of the knee demonstrate marked narrowing of the medial joint space with moderate sclerosis of the adjacent bony margins on the right knee and lateral joint space loss with bony sclerosis in the left knee. A diagnosis of secondary OA is made.
- For treatment, he is given an intra-articular injection of steroids and started on a daily non-steroidal anti-inflammatory along with a proton-pump inhibitor for gastric protection and referred to physical therapy for quadriceps strengthening. His prednisone dose is decreased to 5 mg a day. Over the next month, he notes marginal improvement in the pain and swelling. He continues to have a significant functional loss related to problems with the right knee and is unable to return to work. A referral to orthopedics is made for consideration of a right knee replacement.
3) The joint fluid is non-inflammatory, with a low total wbc. In general, wbc counts less than 3000/cu mm in synovial fluid are considered non-inflammatory.
4) Asymmetrical joint space narrowing, along with bony sclerosis are characteristic of OA. Other characteristic findings include osteophytes.
5) Joint injections with both depot corticosteroid and hyaluronate preparations have been shown to be beneficial. Oral therapies including acetaminophen and several NSAIDs have demonstrated benefit. It is not possible to have a study comparing joint replacement with a sham operation but surgical intervention in those patients who have failed all alternative treatments is generally acknowledged as providing improved mobility and pain relief.