Compliance with off-label Losartan use after hip arthroscopy is poor and subsequent clinical and functional outcomes are not significant. A prospective study

Background: One of the reasons for revision surgery post-hip arthroscopy (HA) is adhesions. Losartan displays inhibitory effects on transforming growth factor beta (TGF-β) and has been used to mitigate the impact of scar tissue formation and adhesions. This study aimed to assess the compliance of patients undergoing HA with Losartan off-label use, the reasons for non-compliance, and the subsequent short-term patient-related outcomes. Methods: A prospective clinical study evaluated compliance amongst 177 consecutive patients prescribed off-label Losartan for 2 weeks post-HA. A novel questionnaire was developed for patients to complete at their 6-week follow-up to assess compliance and identify reasons for non-compliance. Clinical and functional outcomes were assessed at 1-year follow-up and compared between Losartan-compliant and Losartan-non-compliant patients. Results: The compliance rate was 54%. There were 14.6% (n = 14) who experienced adverse effects in the ‘compliant’ group and 13.6% (n = 11) in the ‘non-compliant’ group. The main reasons for non-compliance were avoiding side effects (55%), forgetting to take the medication (30%), and insufficient education (25%). The patient activation measure (PAM) score correlated compliance directly to a patient activation measure (P-value < 0.0001). Conclusion: No demographic or surgical factors were predictive of adherence. The only significant association with adherance was with lower PAM scores, (95% confidence interval, P-value < 0.0001), highlighting the importance of patient education in optimizing adherence. No early differences in clinical or functional outcomes were found between the groups, raising questions about the short-term benefit of Losartan. Its favourable safety profile and potential to reduce revision risk, as reported in large-scale studies, warrant further investigation.