hip dysplasia unfortunately is very common in the breed see the
stats But you don't here about it much. The reason is hip dysplasia is not nearly the debilating problem in bassets as it is for many of the larger breed dogs for the reason
Baseets carry less percentage of weight on the rear of any dog because the carry the heaviest percentage on the fron legs
The have the largest bone mass as compared to overall weight of any breed ie more bone. More bone means thicker bigger bones and joint area to cover there overall mass therefore less stress on the poor hips
Bassets have short leges, this mean exponentially less torque and stress on the hip as tall dogs.
Therefore many basset are dysplastic without showing any signs. You need to take these factors into consideration when weighing the surgical option. The surgery it self will cause some arthritis to form, will it be greater or less than that which will form in a "basset" hips because of the laxcitity in the joint often times surgery is not the best option, using chondroprotective compounds, antioxidents, moderate exersise and most important of all controling the dogs weight are often more effective. I would strongly recommend consulting with a orthopeadist that knows the breed well