Discussion of the case
A 47-year-old female agriculturist, with a 9-year history of low-grade pain in knees and ankles, presented with worsening pain over the past 6 months and its progression to elbows and shoulders.
She had no significant wrist stiffness and limitation of movements of knees. Inflammatory parameters were normal and radiography of both hands and knees showed grade 3 osteoarthritis changes. Â The other diagnoses to be considered are rheumatoid arthritis and seronegative spondyloarthropathy.
The Kellgren and Lawrence system is a common method of classifying the severity of osteoarthritis (OA) using five grades1.
| Classification
·     Grade 0 (none): definite absence of x-ray changes of osteoarthritis
·     Grade 1 (doubtful): doubtful joint space narrowing and possible osteophytic lipping
·     Grade 2 (minimal): definite osteophytes and possible joint space narrowing
·     Grade 3 (moderate): moderate multiple osteophytes, definite narrowing of joint space and some sclerosis, and possible deformity of bone ends
·     Grade 4 (severe): large osteophytes, marked narrowing of joint space, severe sclerosis, and definite deformity of bone ends |
As per ACR criteria (Table 1) for diagnosing osteoarthritis (OA) of the knee, the age of the patient is generally 50 years, but there is no age specification for hand OA (Table 2). The current patient had symptoms since the age of 37 and the joints involved were the knees and ankles. The pain had recently progressed to elbows and shoulders. The X-ray of knee joints was suggestive of radiological features of OA. The involvement of elbows and shoulders in OA is rare, hence the possibility of RA should be considered. The inflammatory parameters could be normal in the early stages of RA or with very low disease activity. To confirm the diagnosis, the patient was evaluated for anti-CCP and the result was negative. In India, the onset of OA is early and has been reported even in youngsters of ≤40 years of age. The patient is an agriculture labourer and the postures of work include cross-leg and squatting, the chance of OA is higher and occurs at an early age.
Table 1: American College of Rheumatology (ACR) classification criteria for knee OA2
| Clinical and laboratory |
Clinical and radiographic |
Clinical |
| Knee pain |
Knee pain |
Knee pain |
| + at least 5 of 9: |
+ at least 1 of 3: |
+ at least 3 of 6: |
| Â Â Â - Age > 50 years |
   - Age > 50 years |
   - Age > 50 years |
| Â Â Â - Morning Stiffness <30 minutes |
   - Morning Stiffness <30 minutes |
   - Morning Stiffness <30 minutes |
| Â Â Â -Â Crepitus on knee motion |
   - Crepitus on knee motion |
   - Crepitus on knee motion |
| Â Â Â - Bony Tenderness |
|
   - Bony tenderness |
| Â Â Â - Bony enlargement |
|
   - Bony enlargement |
| Â Â Â - No palpable warmth |
|
   - No palpable warmth |
| Â Â Â -Â ESRÂ <40 mm/hour |
|
|
| Â Â Â -Â RFÂ <1:40 |
|
|
| Â Â Â - Synovial fluid compatible with OA |
|
|
| 92% sensitive |
91% sensitive |
95% sensitive |
| 75% specific |
86% specific |
69% specific |
*ESR = erythrocyte sedimentation rate (Westergren); RF = rheumatoid factor; SF OA = synovial fluid signs of OA (clear, viscous, or white blood cell count <2,000/mm3). †Alternative for the clinical category would be 4 of 6, which is 84% sensitive and 89% specific.
Table 2: Classification criteria for OA of hand3
| Hand pain, aching or stiffness, and 3 or 4 of the following features:
·        Hard tissue enlargement of 2 or more of 10 selected hand joints*
·        Hard tissue enlargement of 2 or more distal interphalangeal joint joints
·        Fewer than 3 swollen metacarpophalangeal joints
·        Deformity of at least 1 of 10 selected hand joints
Â
* The 10 selected joints are the second and third distal interphalangeal (DIP), the second and third proximal interphalangeal, and the first carpometacarpal joints of both hands. This classification method yields a sensitivity of 94% and a specificity of 87%. |
The patient's inflammatory parameters were normal, and the stiffness also did not qualify for inflammatory arthritis. In India, the incidence of OA is noted in younger patients and in such patients, all the parameters including anti-CCP may appear normal. In such cases, the possibility of OA primary should be considered. Â Since the patient had symptoms on both knee and hand joints, primary rather than secondary OA should be considered. Moreover, the agricultural occupation would have caused secondary stress on the joints. Early-onset and involvement of DIP indicate the primary variant of OA.
Final diagnosis
Primary Osteoarthritis
Treatment course
Exercise, calcium supplementation, and symptomatic therapy helped to alleviate the symptoms.
Learning points
- OA may show polyarticular presentation.
- It is necessary to exclude other possibilities.
- In India, early presentation of OA is noted.
Reference
- Luijkx T, Pai V. Kellgren and Lawrence system for classification of osteoarthritis of the knee. Dostupno na adresi: http://radiopaedia. org/articles/kellgren-and-lawrencesystem-for-classification-of-osteoarthritis-of-knee. Datum pristupa. 2016;7(6).
- Salehi-Abari I. 2016 ACR revised criteria for early diagnosis of giant cell (temporal) arteritis. Autoimmune Dis Ther Approaches Open Access. 2016;3:1-4.
- Altman, AlarcĂ³n 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 Nov;33(11):1601-10.
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