It sounds more like the possibility of Ehlers Danlos Syndrome than OA or general hypermobile syndrome.
I have EDS type 3 with a cross of 1. It is a genetic disorder, meaning someone in your family history must have had it. Basically it is caused by defunct collagen. You will need to see a geneticist in order to get a proper diagnosis, it's not something any doctor can do since they do a skin biopsy. Most people are not properly diagnosed with EDS and most doctors are uneducated in the this field or area of medicine.
There are 6 types of EDS, 2 of which are fatal, the remainders are not. It is believed that it is possible to have cross types. It is characterized by soft velvety skin, easy bruising and tearing, inability to heal, hypermobile joints, elastic or very stretchy skin, severe scarring, poor wound healing and debilitating musculoskeletal pain. Other types such as vascular have issues with internal organs and mitral valve prolapse. Hip displaysia and scoliosis can be common in many at birth. Early onset of OA is very common due the sublexation and dislocation of joints. Each type of EDS also has their own set of different symptoms and finding out which type someone has is very important.
I had doctors tell me for years they didn't know what was wrong with me when I had the classical symptoms. It wasn't until I was 30 before I was proper diagnosed. There are a few other symdromes that do have hypermobility as a key symptom and a geneticist will be able to determine exactly what may be going on.
Good luck and feel free to ask any questions.
Barbie