Design defects can also be part of a product liability case. In these cases the product itself is not defective, rather the design or the way it was supposed to be made ended up being dangerous and causing injury. These cases are typically more straightforward provided the item was being used for it intended use or a use that is reasonable, given the type of product.
Product liability lawyers aren't as common as personal injury lawyers, but you shouldn't have any problem compiling a nice list of potential candidates if you need one. That being the case, be sure you research each one carefully before they even go on the short list: you'll need to find the ones with the most experience, best educations, and best track records.