What is the rate of developing ankle arthritis or needing ankle replacement after the Osteochondral Autograft Transfer System (OATS) procedure at the talus?

Rate of Ankle Arthritis and Ankle Replacement After OATS Procedure at the Talus

Long-term data following OATS procedure at the talus shows good clinical outcomes with an average 84-month follow-up, though specific rates of progression to ankle arthritis or ankle replacement are not well-documented in the available evidence.

Clinical Outcomes After Talar OATS

The most relevant long-term study of talar OATS procedures demonstrates:

• Significant clinical improvement with AOFAS scores increasing from 50 to 78 points at average 84-month follow-up (range 53-124 months) 1
• Pain reduction with VAS decreasing from 7.8 to 1.5 postoperatively 1
• Functional improvement with Tegner scores increasing from 3.1 to 3.7 1
• 81% of patients showed normal integration or minor incongruity of the transplant on MRI, which correlated with significantly better clinical outcomes 1

Risk Factors for Worse Outcomes

Patients undergoing OATS as a revision procedure (second surgical intervention) had significantly worse clinical outcomes compared to those receiving OATS as primary treatment, with lower AOFAS and Tegner scores plus higher pain scores 1. This suggests that early intervention with OATS, rather than after failed prior procedures, yields superior results.

Context: Ankle Arthritis Progression Rates

While specific data on progression to arthritis after OATS is limited, comparative data from other ankle procedures provides context:

• Post-traumatic ankle OA represents 78% of all end-stage ankle arthritis cases, with secondary arthritis at 13% and primary OA at only 9% 2
• After total ankle arthroplasty (a procedure for end-stage arthritis), adjacent joint progression is modest: 27% advanced 1 grade at the subtalar joint and 31% at the talonavicular joint over 6.5 years, with 60-66% showing no progression 3
• The Agility total ankle replacement series showed 19% progressive subtalar arthritis and 15% progressive talonavicular arthritis at 9-year follow-up, with revision rates of 11% 4

Clinical Implications

The available evidence suggests OATS provides durable symptom relief without documented high rates of progression to ankle replacement, though long-term arthritis development rates are not explicitly quantified in the literature. The procedure appears most effective when:

• Performed as the primary surgical intervention rather than after failed prior procedures 1
• Transplant integration is successful on imaging (81% achieve normal or minor incongruity) 1
• Patients are appropriately selected for the procedure 1

Important Caveats

• MRI surveillance is not routinely indicated unless clinical symptoms persist, as imaging findings do not always predict clinical outcomes 1
• The lack of specific long-term data on arthritis progression or conversion to ankle replacement after OATS represents a gap in the literature
• Given that trauma is the primary cause of ankle OA (78% of cases) 2, the underlying cartilage injury itself—rather than the OATS procedure—may be the primary determinant of long-term arthritis risk