A 70-year-old female patient presents with a complaint of left knee pain with weight-bearing activities. She is also developing pain at rest, pain with stair climbing, and start-up pain.

What ICD-10-CM code(s) is/are reported for left knee pain secondary to underlying primary degenerative arthritis?

a) M17.11
b) M17.10
c) M17.12
d) M17.13

The appropriate ICD-10-CM code for left knee pain secondary to primary degenerative arthritis is M17.12, indicating primary osteoarthritis of the left knee.

Explanation:

The correct ICD-10-CM code that should be reported for left knee pain secondary to underlying primary degenerative arthritis is M17.12. The code M17.12 stands for primary osteoarthritis of the left knee. Osteoarthritis is a type of degenerative joint disease that involves the degradation and eventual loss of cartilage in joints, which can lead to symptoms like pain, stiffness, and reduced function. In the case of the 70-year-old female patient, her symptoms of pain in weight-bearing activities, pain at rest, and difficulty with stair climbing are consistent with this diagnosis. When assigning ICD-10-CM codes, it's essential to be as specific as possible regarding the location and nature of the condition being treated, which is why M17.12 is appropriate as it specifies the condition as affecting the left knee.