Knee Osteoarthritis
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Direct answer
Knee osteoarthritis is the commonest form of joint disease seen in Indian orthopaedic practice, producing activity-related pain, short-lived morning stiffness, crepitus, swelling and progressive difficulty with squatting, cross-legged sitting and stairs. The medial compartment usually wears first, driving the bow-legged varus deformity. Diagnosis is clinical with weight-bearing radiographs showing joint space narrowing, osteophytes, subchondral sclerosis and cysts, and management climbs a stepwise ladder from education, weight loss and quadriceps exercises through analgesics and injections to osteotomy or joint replacement for end-stage disease.
What you must remember
- Symptom signature: pain worsened by use and relieved by rest, stiffness lasting under half an hour, crepitus, effusion and functional loss — squatting and toilet activities suffer early in Indian patients.
- Deformity direction: medial tibiofemoral compartment disease collapses into varus (bow-legged, more common); lateral disease produces valgus (knock-kneed).
- Radiographic quartet: joint space narrowing, marginal osteophytes, subchondral sclerosis and subchondral cysts — graded by the Kellgren-Lawrence system, with osteophytes as its hallmark feature.
- Stepwise care: education, weight reduction, quadriceps strengthening and aerobic exercise are the foundation for every patient and genuinely reduce pain.
- Pharmacotherapy: paracetamol first, then topical non-steroidal anti-inflammatory gels, then oral NSAIDs with gastroprotection chosen for the individual patient; intra-articular corticosteroid gives short-term relief especially with effusion, and repeated injections are discouraged.
- What does not work: arthroscopic lavage for pure osteoarthritis, oral steroids, and unproven supplements — evidence for glucosamine remains weak.
- Surgery: total knee replacement for end-stage tricompartmental disease; high tibial osteotomy to correct varus in the young, active patient with isolated medial disease; unicompartmental replacement in selected medial disease.
Common confusion
Osteoarthritis is confused with inflammatory arthritis: osteoarthritic stiffness is brief, rest eases pain and the erythrocyte sedimentation rate is normal, while inflammatory disease stiffens the joint for over an hour and leaves it hot and swollen. Within osteoarthritis itself, the varus knee is misattributed — it is mechanical collapse of the medial compartment, corrected by osteotomy or replacement rather than any medicine. And a degenerate meniscal tear in an osteoarthritic knee without true locking belongs to physiotherapy, not the arthroscope.
Exam-focused takeaway
NEET-PG asks knee osteoarthritis as an image-plus-management subject. Radiograph stems show a narrowed medial joint space with sclerotic margins and osteophytes and ask for the diagnosis, the grading system (Kellgren-Lawrence) or the deformity (varus). Stepwise-treatment vignettes begin with weight loss, quadriceps exercises and walking aids before drugs, and test steroid injection as short-term therapy for effusion rather than a repeated measure. Surgical stems contrast high tibial osteotomy for the young varus knee with total knee replacement for end-stage disease in the elderly, and a negative-stem asks which option is not indicated — arthroscopic washout for established osteoarthritis. Squatting and cross-legged sitting are frequently written into Indian vignettes.
Frequently asked questions
What are the characteristic X-ray changes of knee osteoarthritis?
Joint space narrowing, marginal osteophytes, subchondral sclerosis and subchondral cysts on weight-bearing films, graded by the Kellgren-Lawrence system.
Why does the osteoarthritic knee become bow-legged?
The medial tibiofemoral compartment bears more load and wears first, so the leg collapses into varus — the commonest deformity of advanced disease.
What is the first-line management of knee osteoarthritis?
Education, weight loss, quadriceps strengthening and aerobic exercise, with paracetamol and topical anti-inflammatory gels before oral NSAIDs.
Do steroid injections help knee osteoarthritis?
They give short-term relief, particularly with an effusion, but repeated injections are discouraged and they do not alter the disease.
When is surgery offered?
High tibial osteotomy for the young active patient with isolated medial disease, and total knee replacement for end-stage painful disease failing conservative care.