I have anterior knee pain below the patella without any trauma; what is the appropriate management?

Anterior Knee Pain Below the Patella Without Trauma

Start with acetaminophen up to 4g/day combined with a structured exercise program focusing on eccentric quadriceps strengthening, and obtain plain radiographs (AP, lateral, and tangential patellar views) if pain persists beyond 6 weeks. 1

Initial Clinical Assessment

Your presentation is most consistent with patellofemoral pain syndrome (PFPS), the most common cause of anterior knee pain in the outpatient setting, particularly affecting physically active individuals under 40 years with a lifetime prevalence of approximately 25%. 2, 3

Key diagnostic features to confirm:

• Pain location: Behind or around the patella, worsened by activities requiring knee flexion 3
• Provocative maneuvers: Anterior knee pain during squatting (91% sensitive, 50% specific for PFPS) 2
• Aggravating factors: Stair climbing, prolonged sitting, running 3, 4
• Physical examination: Assess patellar mobility (ranging from limited to hypermobile), perform decline squat test to reproduce pain 5, 3

Imaging Strategy

Do not obtain imaging initially unless specific red flags are present. 3

Radiographs are indicated only if:

• Pain persists beyond 6 weeks despite conservative treatment 1, 6
• History of trauma or prior knee surgery 3
• Joint effusion present on examination 1
• Age >50 years (to exclude osteoarthritis) 3

When imaging is needed, obtain three views: anteroposterior, lateral, and tangential patellar (Merchant/sunrise) 5, 6, 7

Reserve MRI for: Normal radiographs with persistent symptoms after 4-6 weeks of adequate conservative treatment, or when surgery is being considered 1, 6

First-Line Treatment Protocol

Pharmacologic Management

• Acetaminophen: Up to 4g/day as first-line oral analgesic due to superior long-term safety profile compared to NSAIDs 1
• Topical NSAIDs or capsaicin: Second-line if acetaminophen ineffective, offering excellent safety profiles 1
• Oral NSAIDs: Reserve for patients unresponsive to acetaminophen, with gastroprotection if GI risk factors present 1

Exercise Therapy (Most Critical Component)

Eccentric quadriceps strengthening is the cornerstone of treatment, with evidence showing effectiveness in reducing symptoms and promoting tendon healing. 5, 1

Progressive loading protocol:

• Begin eccentric exercises as pain allows 1
• Progress based on tissue tolerance using the "pacing principle" of "small amounts often" 1
• Incorporate hip strengthening if poor tolerance to loaded knee flexion 1
• Add balance, agility, and coordination exercises to improve functional performance 1

Adjunctive Interventions

• Manual therapy: May improve pain and function when combined with exercise, particularly when symptoms are severe 1
• Patellar taping: Effective when combined with strengthening exercises 3, 8
• Prefabricated foot orthoses: Consider if patient responds favorably to treatment direction tests 1
• Deep transverse friction massage: Recommended to reduce pain in patellar tendinopathy 5

Patient Education and Self-Management

• Explain the benign nature of PFPS and expected recovery timeline 1
• Address pain beliefs and behaviors affecting recovery 1
• Modify risk factors including overuse patterns and training errors 3, 8
• Promote autonomy in self-management skills 1

Reassessment Timeline

Reassess at 6 weeks if no favorable outcomes observed. 1

At 6-week follow-up:

• If no improvement, obtain plain radiographs if not yet done 1, 6
• Consider MRI if radiographs normal but symptoms persist 1
• Evaluate treatment adherence and exercise technique 1

When to Consider Specialty Referral

Surgical referral is indicated for:

• Persistent symptoms despite 6+ weeks of adequate conservative treatment with concerning MRI findings 1
• Radiographic evidence of structural pathology with refractory pain and disability 1
• Specific mechanical pathology identified requiring surgical intervention 1

Common Pitfalls to Avoid

• Do not order MRI without recent radiographs first, as approximately 20% of patients inappropriately receive MRI without prior plain films 7
• Avoid corticosteroid injections unless pain flare is accompanied by effusion 1
• Do not rely solely on NSAIDs without concurrent exercise therapy, as this addresses symptoms but not underlying biomechanical dysfunction 1, 3
• Surgery is rarely indicated and should only be considered after comprehensive rehabilitation program failure 3, 8