Heterotopic Ossification in the Posterior Septum of the Knee Excised by an Arthroscopic Dual Portal Technique: A Case Report.

CASE: We present a 15-year-old adolescent girl with acute onset knee pain and a lesion in the posterior septum (PS) believed to be an infectious process on initial investigations. This was excised successfully using a combination of transseptal and transnotch portals and proven to be a case of heterotopic ossification (HO) within the PS with an excellent outcome within 4 weeks. Our case is unique for the pathology that occurred and the technique of excision. CONCLUSION: HO in the PS is a rare pathology that can be treated arthroscopically using a combination of portals. Removal causes complete resolution of symptoms.