A 56-year-old man was referred after unplanned excision of an infrapatellar 35-mm nodule. The pathological diagnosis was clear cell sarcoma. After pre-operative radiotherapy, the same area as in patient 1 was removed because of similar tumor location, BPTB allograft was fashioned to fit the defect, and the allograft was covered by the free contralateral ALT flap. Post-operative course was uneventful. Post-operative management was similar to Patient 1, with the reduced period of the knee brace maintained in straight of 8 weeks, reflecting on the slightly limited ROM in the previous case. Bone union was completed 1 year after surgery. At 48 months post-operatively, the patient was continuously free of disease and his knee function was satisfactory, with minor knee extension lag (<5 ), knee flexion of 145 , full muscle strength and MSTS score of 30/30.