Hip dysplasia and a weird crawl

[LetTheRiverAnswer]

My ds3 had Developmental Hip Dysplasia and wore a harness from 10 weeks old, until the ultrasound scan showed his hip socket had developed to the normal depth at around 5 months old. He's now 9 months old and when he crawls he does an odd thing with his right leg (the one affected by the dysplasia). He sort of keeps it straight and swings it around, rather than keeping it in the usual crawling position. Up until a few weeks ago he did a bum shuffle/crawl combination so it wasn't so obvious.
When I asked the consultant if there was anything I should keep an eye out for at his last appointment, I was told no, but he does want to see him again when he is walking, around 14 months, due to my family history of hip dysplasia. Does anyone have any experience of this sort of problem? I can't decide if its a 'normal odd' or related to his hip and should get him checked again.