What is the version of the following sentence with correct punctuation?

In the case when joint injuries or diseases occur the pain begins to limit the mobility of the patient and thus the comfort of his life is worse One of the most disturbing joints causeing much trouble is the knee joint
In the case when joint injuries or diseases occur, the pain begins to limit the mobility of the patient and thus the comfort of his life is worse. One of the most disturbing joints, causeing much trouble is the knee joint.