Survival, Clinical and Radiological Outcomes of Total Ankle Arthroplasty With Lateral Transfibular Approach With a Minimum 10 Years Follow up (ZTM10)

Ankle osteoarthritis is a disabling condition that can significantly impair the quality of life of affected patients. Ankle arthrodesis has historically represented the gold standard for treating this condition, but technological advancements achieved with fourth-generation prostheses have considerably improved implant survival and clinical outcomes, making them a viable alternative. Prosthetic implants are mainly categorized into anterior and lateral access approaches; for the latter, short- and medium-term data in the literature are encouraging, but long-term studies (over 10 years) are lacking. The present study aims to determine whether the results recorded so far remain stable in the long term.

The objective of the present study is to evaluate the long-term survival, clinical, and radiological outcomes (minimum 10-year follow-up) of total ankle replacements.

The protocol involves the collection of clinical and radiological data analyzed over the years during outpatient evaluations. Specifically, the evaluations are structured as follows:

1. Evaluation of implant survival at a minimum 10-year follow-up and monitoring of any complications and reoperations using the COFAS Reoperation Coding System (CROCS).

2. Evaluation of clinical outcomes using:

   1. AOFAS Questionnaire (Italian version): a specific clinical score for foot and ankle pathologies; despite its limitations, it is used in the majority of similar studies.
   2. Visual Analog Scale (VAS) for pain assessment to quantify the intensity of pain perceived by the patient.
   3. Ankle joint Range of Motion (ROM).

   All the above data will be collected at two follow-up time points: immediately preoperatively and at the latest follow-up visit (at least 10 years after surgery).

3. Radiological evaluation using weight-bearing X-rays of the operated ankle (AP, ML, and 20° Saltzman views) taken at 6 months postoperatively and at the latest follow-up. This will allow the evaluation of:

   1. Aseptic loosening.
   2. Periprosthetic cyst formation.
   3. Implant subsidence.
   4. Heterotopic ossification.
   5. Osteoarthritis in adjacent joints.
4. Any potential correlation between radiological and clinical data will then be evaluated.
5. Finally, demographic and biometric parameters of the patients will be recorded (sex, age at the time of surgery, BMI), along with any associated surgical procedures performed concurrently with the total ankle replacement using a transfibular approach.