In which situation would the code M77.31 be used?

The code M77.31 specifically refers to a condition involving a calcaneal spur on the right foot. This classification is part of the broader coding framework that distinguishes between various anatomical locations and specific types of bone spurs.

When coding conditions like these, it's essential to accurately represent the location of the health issue, as it influences treatment and insurance processes. M77.31 denotes a right-sided calcaneal spur, making it critical to select this code when documenting or billing for diagnoses related specifically to a spur on the right calcaneus (heel bone).

The other options refer to different locations (left calcaneal spur, right knee spur, left knee spur), which do not align with the coding description of M77.31. Therefore, the choice of the code is essential for correct and precise medical coding in relation to the patient’s specific diagnosis.