What is the appropriate management for a patient presenting with bumps on the knee and accompanying leg pain?

Management of Bumps on Knee with Leg Pain

Begin with plain radiographs (AP, lateral, tunnel, and tangential patellar views) as the first-line imaging for any patient presenting with knee pain, and initiate conservative management with acetaminophen or topical NSAIDs while excluding serious pathology. 1

Initial Clinical Assessment

The presentation of "bumps on knee" with leg pain requires systematic evaluation to distinguish between local knee pathology versus referred pain from the lumbar spine or hip:

• Determine pain distribution: Posterior leg pain radiating from the knee upward suggests L5 or S1 radiculopathy rather than primary knee pathology 2
• Assess for red flags: Progressive motor weakness, bladder/bowel dysfunction, saddle anesthesia, or severe bilateral leg weakness require urgent evaluation 2
• Evaluate mechanical symptoms: Locking, catching, popping, or giving way indicate possible meniscal pathology or loose bodies 1
• Check weight-bearing status: Inability to take 4 weight-bearing steps or flex the knee to 90° mandates immediate radiographs 1
• Palpate systematically: Joint line tenderness (83% sensitivity, 83% specificity for meniscal tears), patellar tenderness, and fibular head tenderness guide diagnosis 1, 3

Imaging Algorithm

Obtain radiographs first in all cases before considering advanced imaging:

• Plain radiographs are mandatory if age ≥45 years with chronic pain, isolated patellar or fibular head tenderness, inability to flex to 90°, or inability to bear weight 1
• MRI without contrast is appropriate only after radiographs are obtained and show normal findings or joint effusion, but pain persists despite 4-6 weeks of conservative treatment 1, 3
• Avoid premature MRI: Approximately 20% of patients inappropriately receive MRI without recent radiographs, leading to unnecessary costs and incidental findings 1

Initial Treatment Strategy

Start conservative management immediately while awaiting imaging results:

First-Line Non-Pharmacologic Treatment

• Exercise therapy including quadriceps strengthening is strongly recommended as first-line treatment 4, 3
• Weight reduction if overweight should be initiated as part of comprehensive management 4
• Continue activity as tolerated rather than bed rest, which reduces disability 2
• Self-management programs and patient education empower better symptom control 4, 3

First-Line Pharmacologic Treatment

• Acetaminophen is the oral analgesic to try first and is the preferred long-term option if successful 4, 1
• Topical NSAIDs are strongly recommended for knee pain as an alternative first-line option 4, 1
• Oral NSAIDs (ibuprofen 600-800mg three times daily) should be optimized if topical agents are insufficient 4, 2

Second-Line Options

• Intra-articular corticosteroid injection is indicated for acute exacerbation of knee pain, especially if accompanied by effusion 4
• Skeletal muscle relaxants are recommended as second-line treatment if first-line agents fail 2
• Duloxetine may be offered as alternative or adjunctive therapy for inadequate response to acetaminophen or NSAIDs 4

Reassessment Timeline

• Reevaluate at 4-6 weeks if symptoms persist without improvement despite conservative management 2, 3
• Earlier reassessment is warranted if neurological deficits develop, pain becomes severe and refractory, or red flag symptoms emerge 2
• Consider MRI at 4-6 weeks if conservative treatment fails and radiographs were non-diagnostic 1, 3

Critical Pitfalls to Avoid

• Do not prescribe prolonged bed rest: Maintaining activity reduces disability and improves outcomes 2
• Do not obtain routine imaging without clinical indication: This exposes patients to unnecessary radiation and identifies incidental findings that may not be clinically relevant 1
• Do not ignore referred pain sources: Lumbar spine and hip pathology frequently present as "knee pain" and are commonly overlooked 5
• Do not assume meniscal tears require surgery: Meniscal tears are incidental findings in the majority of patients >70 years and equally common in painful and asymptomatic knees in patients 45-55 years 1, 3
• Do not delay urgent evaluation: If cauda equina syndrome is suspected (saddle anesthesia, bowel/bladder dysfunction), this is a medical emergency requiring immediate MRI 2

Special Considerations for "Bumps"

If visible or palpable bumps are present on the knee:

• Osgood-Schlatter lesion (tibial apophysitis) is more likely in teenage boys and young men, presenting as a prominent tibial tubercle bump 6
• Bursitis may present as localized swelling and should be assessed for signs of infection versus inflammation 6
• Septic arthritis must be excluded in any patient with acute joint swelling, warmth, and erythema, requiring joint aspiration if suspected 4