Looking for advice on my boyfriend's hip pain

Hey guys! I'm looking for some advice on behalf of my boyfriend, he's been struggling with pain in his outer thigh and hip on his left leg for about 8 months. It feels worse when he does pivoting motions, specifically trying to turn it outwards at all. There is also a spot on his outer upper thigh that if you press lightly it feels a bit hollow compared to the surrounding areas. It seems like it could maybe be a muscle strain but it doesn't make sense that it would last this long... does anyone have experience with this type of thing? Can muscle strains last this long? Are there any other conditions that can cause this type of symptom? The only medical condition he may have that we know of is arthritis, and all he can remember is maybe falling on ice this past winter but he doesn't remember which side he fell on or if the timing of when the pain started lines up. Thank you for any help you might be able to provide!