2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress Paper


Compliance With off Label Losartan use After Hip Arthroscopy is Poor and Subsequent Clinical and Functional Outcomes are not Significant a Prospective Study

Caterina Nicolaou , MBBCH(Wits), FCORth(SA), MMED (Wits) SOUTH AFRICA
Jurek R. T. Pietrzak, MBBCh, FCS(SA)Orth, London UNITED KINGDOM

University of WItwatersrand, Johannesburg, Gauteng, SOUTH AFRICA

The FDA has not cleared the following pharmaceuticals and/or medical device for the use described in this presentation. The following pharmaceuticals and/or medical device are being discussed for an off-label use: Merck, Losartan

Summary

Losartan use and compliance post Hip-Arthroscopy and its relation to post surgical outcomes

Abstract

Background

Hip arthroscopy (HA) is an internationally fast-growing hip preservation procedure. One of the causes of failed HA or the need for revision surgery is adhesions. Losartan is an angiotensin receptor blocker with inhibitory effects on transforming growth factor beta (TGF-b) 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 the off-label use of this medication, reasons for non-compliance and the subsequent short-term patient-related outcomes for both compliant and non-compliant patients.

Methods

A prospective clinical study evaluated the compliance of 177 consecutive patients prescribed off-label Losartan for two weeks postoperatively after HA. All patients underwent HA by a single high-volume hip surgeon for FAI with, at a minimum, intra-operative labral repair. All patients received standard peri-operative education and counselling for Losartan and were prescribed Losartan 25mg twice daily. A novel questionnaire was created for patients to complete at their 6-week follow-up to ascertain compliance and reasons for non-compliance. Clinical and functional outcomes were assessed at a one-year follow-up and outcomes were compared between Losartan compliant and Losartan non-compliant patients. Revision HA and conversion to THA were endpoints.

Results

Age, gender, BMI, ASA Tonnis grade, number of comorbidities and surgical interventions did not influence compliance with off-label Losartan prescription. Compliance rate was 54% and 13.6% of patients (24) experienced side effects. The most common side effects reported were fatigue, weakness, dizziness, headache, nausea and chest pain. Post-operative satisfaction rate at a minimum of 1 year was 96.54% and 97,7% for Losartan-compliant and non-compliant patients respectively. Revision rate, reoperation rate and conversion to THA were zero overall for all 177 patients.

Conclusion

Compliance with post-operative off-label Losartan was poor. Non-compliance cannot be attributed to the side effects. A similar number of patients experienced side effects in the compliant and non-compliant groups (13.6% in the non-compliant group and 14.6% in the compliant group). The main reasons for non-compliance were wanting to avoid side effects (55%), forgetting to take the medication (30%), insufficient education(25%) and polypharmacy(24%). The clinical and functional outcomes were equivalent at a minimum of one year follow-up irrespective of Losartan use and compliance. This brings into question the early short-term value of Losartan post-operatively demonstrated by Su et al. at longer-term follow-up. Further clinical studies are required, and a longer follow-up of this patient cohort may further strengthen the evidence on Losartan use to prevent adhesions.