Patellar instability in skeletally immature patients must be approached with concern of potential damage to physcs. In this article, we present a case of combined knee deformity consisting of genu recurvatum, genu valgum and patella baja which arose subsequent to a pediatric tibial tubercle ventromedialization. Patient was a female who was 22 years old upon first admission. After confirming cartilage to be in good health, the deformity was corrected with a single supratubercular posteriorly and medially based proximal tibial closing wedge osteotomy. At the seventh year follow-up, patient was pain free, functionally satisfied and radiographic evaluation showed correct alignment. This case illustrates the consequent difficulties faced if physeal damage occurs during treatment of patellar instability as well as effectiveness of a single well-planned supratubercular proximal tibial osteotomy treating combined genu recurvatum, genu valgum and patella baja deformities; although anatomic and clinical studies are required to generalize its use.