Wu, JoeyHenry, Arnold2021-07-202021-07-202021-01-23Wu, J., & Henry, A.. (2021, January 23). Avascular Necrosis of the Hip with Truvada Use [Poster presented]. 2021 APAMSA National Conference/Virtual, UA. USAWu, J., & Henry, A.. (2021, June 04). Avascular Necrosis of the Hip with Truvada Use [Poster presented]. IU School of Medicine Student Research Symposium/Indianapolis, IN, USA.https://hdl.handle.net/1805/26274https://doi.org/10.7912/gn4x-3q21Background and Introduction Tenofovir disoproxil fumarate (Truvada) is a common HIV Pre-exposure prophylaxis regimen. Rare side effects such as renal toxicity, bone mineral loss have been reported but well documented relationship between Truvada use and AVN has not been well reported. The patient reported in this case study has no additional risk factor or underlying conditions that predisposes him to AVN of the hip aside from Truvada use. Case presentation 37-year-old gay male who is HIV negative in a monogamous relationship with a male of undetectable HIV viral load on Truvada prophylaxis with goal of decreasing HIV transmission risk. He began taking Truvada in Jan of 2015 and was without complications until Apr 2018 when he presented with left hip/quadricep pain initially diagnosed with IT band syndrome. He failed to improve with multiple courses of physical therapy and pain has been recurrent. He received X-ray of pelvis, bilateral hips, and lumbar spine with 4 views in Jun 2019. Result was significant for avascular necrosis of the left hip. He has no other comorbidities and began taking NSAIDs for pain control. His Truvada was discontinued Jun 2019 and pt began Descovy (Tenofovir alafenamide fumarate) but his ROC visit/imaging in Aug 2020 shows worsening AVN and symptomatic pain. Physical exam also shows significant atrophy of left lower extremity muscle groups and antalgic gait. Conclusion Truvada has been associated with AVN in patients without previous health risks for decreased bone health/density. Previous research have identified improved bone mineral density with discontinuing Truvada and beginning Descovy. However, this patient fails to improve with Descovy and continues to have worsening AVN, perhaps suggesting AVN is not associated with bone mineral loss but possibly other occult reasons.en-USPoster10.7912/gn4x-3q21