Management of Mild Extensor Mechanism Tendinosis with Knee Pain Post-Arthroplasty
For this patient with mild extensor mechanism tendinosis following knee arthroplasty, initiate eccentric strengthening exercises as the primary treatment, combined with short-term NSAIDs for pain control and relative rest from aggravating activities. 1
First-Line Treatment Approach
Eccentric Strengthening Exercises (Cornerstone of Treatment)
- Eccentric exercises are the most evidence-based intervention for extensor mechanism tendinosis, reducing symptoms, increasing strength, and promoting tendon healing by stimulating collagen production and guiding normal alignment of newly formed collagen fibers. 1
- Prescribe quadriceps and surrounding muscle group training 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. 1
- Allow 2-3 minutes rest between sets to optimize strength gains. 1
- Heavy slow resistance training (≥80% of 1RM) is an effective alternative approach for long-term improvements in knee function. 1
Activity Modification
- Implement relative rest by reducing repetitive loading activities that reproduce pain, particularly jumping and stair navigation. 1
- Critical pitfall: Never prescribe complete immobilization, as this causes muscular atrophy and deconditioning. 1
Pain Management
- Use oral or topical NSAIDs for short-term pain relief, though they do not affect long-term outcomes. 1, 2
- Topical NSAIDs are preferable as they eliminate the increased risk of gastrointestinal hemorrhage associated with oral formulations. 1, 2
- Apply cryotherapy through a wet towel for 10-minute periods for effective acute pain relief. 1
Adjunctive Therapies
Manual Therapy
- Deep transverse friction massage reduces pain and may provide additional benefit when combined with other interventions. 1
Complementary Exercises
- Perform stretching exercises for the quadriceps and hamstrings 2-3 days per week, holding static stretches for 10-30 seconds, with daily stretching providing the greatest gains. 1
- Warm muscles through light aerobic activity before stretching for optimal effectiveness. 1
- Incorporate low-impact aerobic exercises such as walking or cycling for 30-60 minutes per day at moderate intensity on most days to maintain cardiovascular fitness and support tendon health. 1
Secondary Treatment Options (If First-Line Fails)
- Corticosteroid iontophoresis is effective for treating patellar tendon pain and improving function. 1
- Critical pitfall: Never inject corticosteroids directly into the tendon substance, as this inhibits healing, reduces tensile strength, and predisposes to spontaneous rupture. 1
Patient Education
- Explain that the condition represents chronic tendinosis rather than acute inflammation. 1
- Address hypersensitivity and build confidence by emphasizing that pain doesn't necessarily correlate with tissue damage. 1
- Set realistic expectations: approximately 80% of patients recover completely within 3-6 months with appropriate conservative treatment. 1
Progression Strategy
- Gradually increase resistance and/or repetitions per set and/or frequency as strength improves. 1
- Progress from basic strengthening to sport-specific exercises as symptoms improve. 3
- If favorable outcomes are not observed after a realistic trial period, reassess the intervention strategy. 1
When to Consider Surgery
- Surgery is justified only after 3-6 months of well-managed conservative treatment has failed. 1
- Surgical options include open or arthroscopic excision of abnormal tendinous tissue and longitudinal tenotomies to release areas of scarring and fibrosis. 1
Special Considerations for Post-Arthroplasty Patients
Given the MRI limitations from arthroplasty artifacts, clinical examination and functional assessment become paramount for monitoring progress. The finding of only mild tendinosis is reassuring and suggests excellent prognosis with conservative management. 1