What is the treatment for a high-grade partial thickness tear of the Achilles tendon?

Treatment for High-Grade Partial Thickness Tear of Achilles Tendon

High-grade partial thickness tears of the Achilles tendon should be considered for surgical treatment, as recent biomechanical evidence demonstrates that partial ruptures affecting even less than 50% of the tendon's width can progress to complete ruptures during functional rehabilitation protocols. 1

Critical Decision Point: Surgical vs. Conservative Management

The traditional "50% rule" (conservative management for tears <50% of tendon width) requires reconsideration based on current evidence:

• Biomechanical modeling shows that partial ruptures can progress to complete ruptures under loading conditions from functional rehabilitation, even when affecting less than 50% of tendon width 1
• This progression occurs regardless of subtendon twisting patterns and material properties (healthy vs. tendinopathic tissue) 1
• Approximately 25% of athletes with Achilles tendon overuse injuries ultimately require surgery, with frequency increasing with symptom duration and presence of tendinopathic changes 2

Surgical Approach (When Indicated)

For high-grade partial tears requiring surgery, percutaneous or limited open repair techniques are preferred over standard open repair:

Technique Selection

• Percutaneous repair results in significantly less wound breakdown/delayed healing and fewer scar adhesions compared to open repair 3
• Limited open repair allows faster return to normal walking, stair climbing, and sports compared to standard open repair 3
• Limited open repair has significantly fewer severe wound infections and superficial infections versus open repair 3
• Open repair carries higher rates of wound complications and infection 3

Post-Operative Protocol

• Begin early protected weight bearing within 2 weeks following repair 3
• Use a walking boot that limits dorsiflexion to protect the healing tendon 3
• Begin mobilization by 2-4 weeks using a protective device 3
• Early weight bearing (≤2 weeks) enables quicker return to activities during the first 6 months compared to traditional non-weight bearing protocols 3
• By 12 months, outcomes (pain and function) are similar regardless of early or delayed weight bearing protocols 3

Conservative Management (Selected Cases Only)

Conservative treatment may be attempted in lower-grade partial tears with close monitoring for progression:

Immobilization and Protection

• Progress to protected weight bearing within 2 weeks if possible 4
• Transition to a protective device that limits dorsiflexion after initial immobilization 4
• Begin mobilization by 2-4 weeks using a protective device 4, 5

Adjunctive Therapies

• Cryotherapy applied through wet towel for 10-minute periods provides acute pain relief 5
• NSAIDs (topical or systemic) for short-term pain relief, with topical formulations having fewer systemic side effects 5
• Eccentric strengthening exercises should be implemented as they may reverse degenerative changes 5

Emerging Biological Treatments

• Autologous platelet-rich plasma (PRP) injections may promote rapid tendon healing in partial tears, though this represents a less-established approach 6
• Case reports suggest multiple PRP injections (approximately 6.5 billion platelets, 3 times, 7 days apart) may accelerate tissue repair 6

Diagnostic Confirmation

MRI or ultrasound should be obtained to accurately characterize tear severity:

• MRI detects 26 of 27 cases of Achilles tendinosis and partial rupture with >90% sensitivity 7
• Ultrasound can differentiate full-thickness from partial-thickness tears with 92% accuracy 7
• Ultrasound has 100% sensitivity and 93% accuracy compared with surgical findings, though results are operator-dependent 7

Critical Monitoring and Complications

Rerupture Prevention

• Patient compliance with protective protocols is crucial to prevent rerupture 4, 3
• Non-compliance with protective devices significantly increases rerupture risk 5
• Conservative treatment of significant partial ruptures responds poorly and does not improve with time 2

Complications to Monitor

• Deep vein thrombosis requires monitoring regardless of treatment approach 4, 3, 5
• Residual tendon lengthening affecting function 4
• Sural nerve injuries can occur with both percutaneous and open surgical techniques 3
• Wound puckering occurs more frequently with percutaneous repair 3

Common Pitfalls

• Avoid relying solely on the "50% rule" for treatment decisions, as biomechanical evidence shows progression can occur with smaller tears 1
• Do not delay surgical consultation for chronic partial ruptures, as the best treatment for chronic partial rupture appears to be surgery 2
• Approximately 20% of injured athletes require re-operation for Achilles tendon overuse injuries 2
• About 3-5% of athletes are compelled to abandon their sports career despite treatment 2

Expected Outcomes

• Most patients with tendon injuries fully recover within 3-6 months with appropriate treatment 5
• Following surgery, approximately 70-90% of athletes have successful return to sport after Achilles tendon injury 2
• Surgery is required in about 25% of athletes with Achilles tendon overuse injuries 2