Heterotopic ossification within an arthroscopic portal after uneventful partial meniscectomy.

We report the case of a 44-year-old man who underwent a partial medial meniscectomy for a meniscal tear whose postoperative course was complicated by the development of heterotopic ossification (HO) within the medial arthroscopic portal. Following a routine initial procedure, the patient presented with ongoing pain and a palpable, painful lump around the previous medial arthroscopy portal. Plain radiographs and MRI were suggestive of a bony structure within the soft tissues.