Estimation of Patient Acceptable Symptom State (PASS) and Treatment Failure (TF) Threshold Values for the Achilles Tendon Total Rupture Score (ATRS) at 6 Months, 1 Year, and 2 Years After Acute Achilles Tendon Rupture

Abstract

Interpretation of the Achilles tendon Total Rupture Score (ATRS) is challenging because limited knowledge exists about at which score the patients consider the outcome of treatment as satisfactory. The aims of the study were (1) to describe the proportion of patients who find their symptom levels to be satisfactory, to reflect treatment failure or neither after acute Achilles tendon rupture (ATR), and (2) to estimate the Patient Acceptable Symptom State (PASS) and the Treatment Failure (TF) threshold values for the ATRS at 6 months, 1 year, and 2 years after ATR. The study was based on data extracted from the nationwide Danish Achilles tendon Database which includes patients treated operatively or nonoperatively after ATR. The PASS and TF threshold values for ATRS were estimated using the adjusted predictive modeling method. One hundred and sixty-six patients were included at 6 months, 248 patients at 1 year, and 287 patients at 2 years after ATR. The proportion of patients who considered their symptom level to be satisfactory was 61% at 6 months, 50% at 1 year, and 66% at 2 years, while 5% at 6 months, 11% at 1 year, and 10% at 2 years considered their symptom level to reflect treatment failure. The PASS threshold value for ATRS (95% confidence interval) was 49 (46-52) at 6 months, 57 (54-60) at 1 year, and 52 (49-55) at 2 years. The TF threshold value for ATRS was 30 (23-36) at 6 months, 33 (26-40) at 1 year, and 35 (29-39) at 2 years. The calculated PASS and TF threshold values can help interpret the outcome of ATR when measured with the ATRS. About 50% to 66% of the patients had a satisfactory symptom level after ATR.

Keywords: Achilles; Achilles tendon rupture; ankle; conservative; nonoperative; operative; outcome; patient-reported outcome measure; satisfaction; treatment.