Initial Treatment for Partial Thickness Intrasubstance Achilles Tendon Tear
Conservative management with relative rest, activity modification, eccentric strengthening exercises, and progressive tendon loading is the recommended initial treatment for partial thickness intrasubstance Achilles tendon tears. 1
Immediate Management Approach
Activity Modification and Rest
- Implement relative rest by reducing activities that provoke pain while avoiding complete immobilization to prevent muscle atrophy and deconditioning 1
- Weight-bearing should be modified based on pain tolerance, as complete immobilization leads to muscular atrophy 1
Pain Management
- Apply cryotherapy (ice) through a wet towel for 10-minute periods to provide short-term pain relief 1
- Avoid corticosteroid injections directly into the tendon substance, as they inhibit healing, reduce tensile strength, and may predispose to spontaneous rupture 1
Progressive Rehabilitation Protocol
Eccentric Strengthening (Cornerstone of Treatment)
- Eccentric strengthening exercises are the primary therapeutic intervention to reduce symptoms, increase strength, and promote tendon healing 1
- Tensile loading stimulates collagen production and guides normal alignment of newly formed collagen fibers 1
- Deep transverse friction massage may be combined with eccentric exercises to help reduce pain 1
Treatment Duration and Monitoring
- Conservative management should be continued for 3-6 months before considering surgical intervention if treatment fails 1
- A 12-week course of conservative treatment including exercise, tendon loading, electrical stimulation, and photobiomodulation has shown effectiveness in returning athletes to pre-injury activity levels 2
Critical Pitfalls and Considerations
The "50% Rule" May Be Inadequate
- Recent biomechanical evidence suggests that partial ruptures affecting less than 50% of tendon width may still progress to complete ruptures during functional rehabilitation 3
- This challenges the traditional conservative approach for tears under 50% and suggests closer monitoring is essential 3
When Conservative Treatment Fails
- Significant partial ruptures may respond poorly to conservative measures and do not improve with time 4
- Persistent pain despite 3-6 months of conservative treatment indicates the need for surgical evaluation 1
- Surgical excision of degenerated tissue leads to complete pain relief and full restoration of function with long-standing effects in most cases of persistent symptoms 4
Diagnostic Confirmation
- MRI is the gold standard with 95% sensitivity and specificity for detecting partial tears and chronic degenerative changes 5
- Physical examination should include Thompson test, assessment of plantar flexion strength, palpation for gaps, and comparison of passive dorsiflexion 6, 5
- Partial tears may present with less pronounced weakness, ability to perform single heel raise with pain, and minimal palpable defect 5
Alternative Biological Approaches
While not standard first-line treatment, autologous platelet-rich plasma (PRP) injections have shown promise in case reports for promoting rapid tendon healing and swift return to competitive sports activity 7. However, this remains investigational and should not replace standard conservative management as initial treatment.