Background: High tibial osteotomy (HTO) is a treatment option for relatively young patients with isolated medial compartment arthritis of the knee. Medial open wedge osteotomies allow easier control of correction, but can lead to patella infera as a result of distalization of the tibial tubercle. This retrospective study reports results of a biplanar tibial tubercle preserving HTO, designed to preserve patellar height.Methods: The study is a retrospective analysis of 12 consecutive patients (11 men, 1 woman) average age 39.6 years who underwent the procedure between 2009 and 2012. A biplanar open wedge tibial osteotomy was performed and stabilised with a medial locking plate. Patients were allowed full weight bearing at 6 weeks. Preoperative and postoperative function was recorded on the Oxford knee score, Lysholm score and Tegner activity scale. Minimum follow up was 26 months.Results: All patients had healing of the osteotomy with no delayed union. Eleven patients reported improvement in symptoms with an average preoperative Oxford score of 26 and postoperative score of 39 out of 48. The Lysholm score improved from 58 to 72 out of 100. There was one point improvement in Tegner activity scale. There was no statistical difference in patellar height before and one year after surgery. The correction in varus averaged 8.3°.Conclusion: The biplanar High tibial Osteotomy allows preservation of patellar height, while achieving desired varus correction. [ABSTRACT FROM AUTHOR]