How should patellar tendinitis (jumper’s knee) be evaluated and managed in a young active athlete?

Patellar Tendinitis (Jumper's Knee): Evaluation and Management

Initial Evaluation

Begin with a structured physical examination focusing on pain at the inferior pole of the patella during resisted leg extension with the knee fully extended, and perform a decline squat test to reproduce symptoms by loading the patellar tendon. 1, 2

Key Clinical Features to Identify:

• Pain location: Tenderness specifically at the inferior pole of the patella where the tendon inserts 2
• Pain pattern: Activity-related anterior knee pain that worsens with jumping, navigating stairs, and prolonged sitting 1, 2
• Provocative testing: The decline squat test places increased load on the patellar tendon and typically reproduces the patient's pain 1, 2

Diagnostic Imaging:

• Ultrasonography is 94% specific, showing tendon thickening, decreased echogenicity, and calcification 2
• MRI is 78% sensitive and 86% specific, useful for visualizing chronic degenerative changes and ruling out other pathology 2

First-Line Conservative Management (3-6 Months)

Eccentric strengthening exercises are the gold standard treatment and should be implemented immediately, achieving full recovery in approximately 80% of patients within 3-6 months. 2

Structured Exercise Protocol:

• Eccentric quadriceps strengthening: Train 2-3 days per week at 60-70% of one-repetition maximum for 8-12 repetitions across 2-4 sets, with at least 48 hours rest between sessions 3
• Progression: Advance to heavy slow resistance training (≥80% of 1RM) as strength improves and tolerance increases 3
• Include both hip and knee-targeted exercises, with the balance determined by tolerance to loaded knee flexion 3
• Complementary stretching: Hamstring and quadriceps stretching 2-3 days per week, holding static stretches for 10-30 seconds after warming up 3

The mechanism is that eccentric exercises stimulate collagen production and guide normal alignment of newly formed collagen fibers 2

Activity Modification:

• Relative rest: Reduce or eliminate pain-provoking activities (particularly repetitive jumping and loading), but continue activities that don't worsen symptoms to prevent muscular atrophy 3, 2
• Allow low-impact aerobic activities like cycling or swimming to maintain cardiovascular fitness 3
• Avoid complete immobilization, which causes deconditioning 2

Adjunctive Pain Management:

• Deep transverse friction massage is recommended to reduce pain 1, 3
• Topical NSAIDs are preferred over oral NSAIDs to eliminate gastrointestinal hemorrhage risk while providing pain relief 3, 2
• Cryotherapy: Apply ice through a wet towel for 10-minute periods for acute pain relief after activity 3, 2
• Medially directed patellar taping for short-term pain relief and improved function, particularly during rehabilitation exercises 3

Critical Caveat:

Never inject corticosteroids into the patellar tendon, as this inhibits healing, reduces tensile strength, and predisposes to spontaneous rupture. 3 While corticosteroid iontophoresis (non-invasive delivery) has been shown effective for patellar tendinosis pain 1, direct injection is contraindicated.

Surgical Intervention

Surgery should be reserved exclusively for patients who have failed conservative therapy for 3-6 months and continue to experience significant pain affecting quality of life or inability to return to desired activity level. 4, 5

Surgical Indications:

• Conservative treatment failure after 3-6 months 4
• Persistent significant pain affecting quality of life 4
• Inability to return to desired activity level despite appropriate non-surgical management 4

Surgical Approach:

Arthroscopic treatment is the preferred surgical method over open procedures, with a 91% success rate compared to 87% for open surgery, and significantly faster return to sporting activities (8-12 weeks versus 8-12 months). 6, 5

The arthroscopic technique includes:

• Debridement of soft tissue at the lower patellar pole 6
• Resection of the bony lower patellar pole if prominent 6
• Excision of abnormal tendon tissue 4
• Longitudinal tenotomies to release areas of scarring and fibrosis 4

Surgical Outcomes:

Arthroscopic treatment leads to excellent clinical results comparable to open treatment but provides the benefits of a minimally invasive procedure with faster recovery 6, 5. Most athletes return to their previous level of sports 8-12 weeks after arthroscopic surgery 7, 6, compared to 8-12 months after open surgery 5.

Patient Education

Explain that pain doesn't necessarily correlate with tissue damage, set realistic expectations for a 3-6 month recovery timeline with conservative treatment, and promote autonomy to reduce fear of movement. 3 For overweight patients, weight loss counseling should be included as part of the comprehensive treatment plan 3.