You can get around it by reverse engineering it as long as what's sold doesn't violate that patent. Many companies have had to reverse engineer an existing patent to figure out what they can do instead.

https://en.wikipedia.org/wiki/Design_around

> Design-arounds are considered to be one of the benefits of patent law. By providing monopoly rights to inventors in exchange for disclosing how to make and use their inventions, others are given both the information and incentive to invent competitive alternatives that design around the original patent. In the field of vaccines, for example, design-arounds are considered fairly easy. It is often possible to use the original patent as a guide for developing an alternative that does not infringe the original patent.