A 52-year-old woman with a 10-year history of osteoarthritis of the right knee presents with progressive pain, morning stiffness lasting 30 minutes, and functional limitation affecting her activities of daily living. She has failed conservative management including NSAIDs, physiotherapy, and intra-articular corticosteroid injections over the past 6 months. On examination, she has varus deformity, crepitus, and restricted range of motion. Plain radiographs show Kellgren–Lawrence Grade 3 osteoarthritis. What is the most appropriate next step in management?

Explanation

## Management of End-Stage Knee Osteoarthritis **Key Point:** When conservative measures fail in symptomatic osteoarthritis with radiographic evidence of advanced disease (Kellgren–Lawrence Grade 3–4), orthopedic referral for surgical evaluation (total knee arthroplasty) is the appropriate next step. ### Kellgren–Lawrence Grading System | Grade | Radiographic Features | Clinical Correlation | |-------|----------------------|----------------------| | 0 | No osteoarthritis | Normal | | 1 | Doubtful narrowing, possible osteophytes | Minimal symptoms | | 2 | Definite osteophytes, possible narrowing | Mild symptoms | | 3 | Moderate narrowing, osteophytes, sclerosis | Moderate-to-severe symptoms, functional limitation | | 4 | Severe narrowing, large osteophytes, deformity | Severe symptoms, significant disability | ### Indications for Total Knee Arthroplasty (TKA) **High-Yield:** TKA is indicated when: 1. **Radiographic evidence** of advanced OA (Kellgren–Lawrence Grade 3–4). 2. **Failed conservative management** (NSAIDs, physiotherapy, intra-articular injections for ≥6 months). 3. **Significant functional impairment** affecting ADLs and quality of life. 4. **Patient motivation** and realistic expectations. 5. **Age typically ≥50 years** (though not absolute). This patient meets ALL criteria: Grade 3 OA, failed 6 months of conservative therapy, functional limitation, and age 52. ### Conservative-to-Surgical Progression ```mermaid flowchart TD A[Symptomatic knee OA]:::outcome --> B[NSAIDs, weight loss, physiotherapy]:::action B --> C{Response at 3 months?}:::decision C -->|Good| D[Continue conservative management]:::action C -->|Poor| E[Intra-articular corticosteroid injection]:::action E --> F{Response at 6 months?}:::decision F -->|Good| G[Repeat injections as needed, max 3-4/year]:::action F -->|Poor| H[Assess for viscosupplementation or TKA]:::decision H -->|KL Grade 1-2, young| I[Hyaluronic acid, continue conservative]:::action H -->|KL Grade 3-4, functional limitation| J[Orthopedic referral for TKA evaluation]:::action J --> K[TKA if patient suitable]:::action ``` **Clinical Pearl:** Intra-articular corticosteroid injections are typically limited to 3–4 per year because repeated injections may accelerate cartilage degeneration. This patient has already received injections over 6 months without sustained benefit, making her a candidate for definitive surgical management. **Warning:** Hyaluronic acid (viscosupplementation) is a bridge therapy for mild-to-moderate OA (KL Grade 1–2) or when patients are not yet ready for surgery. In Grade 3 OA with failed conservative management, it delays rather than replaces the need for TKA and is not the "next step" — orthopedic referral is.