A Comparative Analysis of Clinical Outcomes in Noninsertional Versus Insertional Tendinopathy Using PROMIS.

Background. Achilles tendinopathy is a common clinical disorder. Utilizing the Patient-Reported Outcomes Measurement Information System, we aim to determine clinical response to nonoperative achilles tendinopathy rehabilitative care of insertional achilles tendinopathy compared to non-insertional achilles tendinopathy. Methods. Prospective Patient-Reported Outcomes Measurement Information System Physical Function, Pain Interference, and Depression scores were collected for patients with achilles tendinopathy at presentation and following a standard course of nonoperative care. A distribution-based method was used to determine the minimal clinically important difference. Descriptive statistics were reported and bivariate analysis was used to compare insertional achilles tendinopathy and non-insertional achilles tendinopathy. Receiver operating characteristic curve analysis was used to predict clinical improvement. Results. A total of 102 patients with an average follow-up of 68 days were included. For the non-insertional achilles tendinopathy group: Fifteen (46%), 12 (36%) and 9 (27%) patients reached clinical improvement for Physical Function, Pain Interference and Depression, respectively. For the insertional achilles tendinopathy group: Seventeen (25%), 20 (29%) and 22 (32%) patients reached clinical improvement for Physical Function, Pain Interference and Depression, respectively. Physical Function scores improved more in non-insertional achilles tendinopathy patients (4.0 vs. -0.046; p = 0.035) and more patients clinically improved (45.5% vs. 24.6%; p = 0.034). Patients with non-insertional and insertional achilles tendinopathy clinically improved functionally when initial Physical Function scores were equal to or lower than 40.25 and 38.08, respectively. Conclusions. Nonoperative care in achilles tendinopathy is often successful. The Patient-Reported Outcomes Measurement Information System can be used to evaluate and help determine clinical success. Levels of Evidence: Level II: Prospective comparative study.