Pathology/Lab Coding Alert

Question: Our pathologist received a container labeled "bone and tissue, left hip." It consisted of one femoral head with a focal erosion area and multiple irregular bone fragments and a fibrous tissue fragment. After decalcification, the pathologist's final diagnosis was "bone and adjacent articular cartilage with changes of degenerative joint disease." How should we code the case?

Iowa Subscriber

Answer: The correct coding is 88304 (Level III -- Surgical pathology, gross and microscopic examination, femoral head, other than fracture) and +88311 (Decalcification procedure [List separately in addition to code for surgical pathology examination]). The correct diagnosis code is 715.95 (Osteoarthrosis, unspecified whether localized or generalized, pelvic region and thigh).

Although the specimen is almost certainly from hip replacement surgery, you should not use the code for joint resection (88305, Level IV -- Surgical pathology, gross and microscopic examination, joint, resection).

Here's why: Unlike a knee replacement, which involves bone from both sides of the joint, a hip replacement specimen typically involves only the femoral head, not the acetabelum. In your case, it is true that the specimen did not include the acetabelum. That said, CPT provides more specific coding options than "joint resection." In fact, CPT provides two codes for femoral head based on whether the specimen involves a fracture: 88304 or 88305 (Level IV--Surgical pathology, gross and microscopic examination, femoral head, fracture). In your case, the pathology report did not identify a fracture, so you should use 88304.

Don't forget decalcification: You should use add-on code +88331 to capture the specimen decalcification that preceded the pathology exam.

Use unspecified Dx: Because the pathologist bases the diagnosis on findings limited to the femoral head specimen, you should be careful not to generalize about the patient's overall joint conditions. That's why you should select 715.9 instead of the more specific codes such as 715.0 (Osteoarthritis, generalized) or 715.1 (Osteoarthrosis, localized, primary). Don't forget to select the fifth digit based on the site -- in this case, 715.95 for pelvic region.