I got a memory foam topper for my bed as the mattress is so hard and it has made a difference.

I had a 4 inch memory foam mattress topper on my old be and that allowed me to sleep without the extreme hip pain. I used a total of 4 pillows to sleep at night.
Recently, just bought an adjustable Casper bed and I sleep with 1 pillow, and that is under my head! I love the zero gravity and fall asleep in this position, then lower the feet to turn side to side. I still have some breakthrough hip pain, but am thinking of getting another foam mattress topper for that. Greatest investment!

I have now settled with a memory foam mattress with a good quality topper. Strange combo but works for me. I would recommend spend as much as you can afford for your topper as I've used cheaper ones to no effect.

The one I got has a cover that is like a fitted sheet which is excellent, I think it came from Scott’s of Stowe. I got one for my son when he came back from Uni, just fibre filled, and that one only had elastic at the corners to hook under the mattress which pop out easily. He says it helps and was certainly cheaper than the memory foam.

Thanks I have been thinking of buying a topper for my bed but I thought I get some insight. You've been helpful