Osteochondroma of the Tibial Tubercle Masquerading as Osgood-Shlatter Disease: A Case Report

BACKGROUND: Osteochondromas are a relatively common primary bone tumor, which may share common clinical features with Osgood-Schlatter disease (OSD). A limited number of cases have described tumors misdiagnosed as OSD. CASE PRESENTATION: We report the case of an 11-year-old male with a sessile osteochondroma of the tibial tubercle and concomitant involvement of the distal extension and attachment of the patellar tendon into the tibial periosteum. A prior diagnosis OSD had been made. The lesion was resected and repair of the extensor mechanism was required at the time of surgery. The patient was followed for 20 months postoperatively and had restoration of knee function with minimal pain, as demonstrated by a PEDI-IKDC score of 94.6 at 19-month. CONCLUSION: This is a rarely reported case of benign tumor masquerading as OSD requiring excisional biopsy with extensor mechanism repair.