Query: Medial Malleolus Exostosis
A patient has an exostosis of the tibial
malleolus. The surgeon made a linear incision
through the capsular and periosteal structures
in the medial malleolar area, and excised a
large portion of the bone (exostosis) from the
tibial malleolus using an osteotome and mallet.
A rongeur was then used to removal any bony
projections and smooth the entire area.
Taber's Dictionary says an exostosis is a bony
growth that arises from the surface of a bone.
The description of this type of procedure
appears to be the chiseling off of the bony
protuberance (CPT 27635) and not an actual
craterization of the bone (CPT 27640).
Would this be best billed as CPT 27640 (partial
excision of bone, tibia), or CPT 27635 (excision
or curettage of bone cyst or benign tumor, tibia
or fibula)?
Deb Carr, CCS
Enola, PA
Codingline response: Based on the surgeon's
description, I believe that the best code for
removal of a tibial exostosis would be CPT 27640
(partial excision of bone, tibia). The location
of the exostosis on the tibia is not relevant. I
believe that specifically the diagnosis of
exostosis vs. bone cyst is the factor that makes
CPT 27640 the correct code.
Howard Zlotoff, DPM
Camp Hill, PA
