Focused examination for knee osteoarthritis including alignment assessment, compartmental involvement, effusion detection, and functional evaluation.
Knee OA examination requires systematic assessment of alignment, compartmental involvement, and functional status. Examiners expect you to identify the pattern of arthritis (medial, lateral, or patellofemoral), assess severity, and evaluate the patient's suitability for different treatment options.
High-Yield Exam Summary
Tibiofemoral OA:
Patellofemoral OA:
Tricompartmental OA:
Alignment and Arthritis:
Alignment determines which compartment wears first and guides treatment options.
Front View:
Lateral View:
Behind (With Patient Walking):
Clinical Assessment (Standing):
Inter-condylar Distance:
Inter-malleolar Distance:
Weight-Bearing Assessment:
Antalgic Gait:
Varus Thrust:
Valgus Thrust:
Trendelenburg:
Stiff Knee Gait:
Bony Landmarks:
Effusion Assessment:
Temperature:
Patellofemoral:
Detect moderate to large knee effusion
Patella 'clicks' against femoral trochlea (floating on fluid)
Moderate to large knee effusion (greater than 30mL typically)
Ability to detect true positives
Ability to exclude false positives
Detect small knee effusion
Wave of fluid returns to medial side
Small knee effusion (more sensitive than ballottement)
Ability to detect true positives
Ability to exclude false positives
Extension:
Flexion:
Assessment Technique:
Record as: 0° to 130° (normal) or 15° to 110° (FFD to max flexion)
Functional ROM Requirements:
A patient with 0-90° ROM can walk and climb stairs but may struggle with deep bending.
Why Important in OA:
Tests:
Correctable vs Fixed Deformity:
Patellofemoral OA/chondromalacia
Pain with compression or contraction
Patellofemoral joint pathology (OA, chondromalacia)
Ability to detect true positives
Ability to exclude false positives
Patellofemoral pathology
Pain or inability to contract due to pain
Patellofemoral pathology (note: high false positive rate)
Ability to detect true positives
Ability to exclude false positives
Observation:
Palpation:
Functional:
Gait Assessment:
Stairs:
Rising from Chair:
ADLs:
Document Pain:
| severity | rom | alignment | effusion | function |
|---|---|---|---|---|
| Mild | Full or near full | Minimal deformity | None or minimal | Mild limitation |
| Moderate | Some limitation | Obvious varus/valgus | May be present | Moderate limitation |
| Severe | Significantly limited | Fixed deformity | Often present | Significant disability |
| End-stage | Marked limitation, FFD | Severe fixed deformity | Variable | Unable to function normally |
Conservative Treatment Indicators:
Osteotomy Consideration (HTO/DFO):
Unicompartmental Knee Replacement:
Total Knee Replacement:
"68-year-old man with progressive right knee pain over 5 years, now affecting sleep."
High-Yield Exam Summary