Author's reply

Sir,

Thank you for your interest in our article entitled “A retrospective analysis of medial opening wedge high tibial osteotomy for varus osteoarthritic knee.”¹ According to your concern about our technique,² medial opening wedge high tibial osteotomy (MOWHTO) using a Tomofix plate without any bone graft or substitute, we corrected the larger series of 68 patients who underwent 81 osteotomies with the use of this technique.³ Non-united osteotomies and recurrent varus deformity were found to be 2.4% and 1.4%, respectively. No implant breakage was detected in our study. Although Miller et al.⁴ reported the high rate of complications (36.9%) with this technique. Their study used Puddu plate or VS osteotomy plate fixation with autograft or allograft insertion. We thought that these kinds of two plates had too short lever arm to withstand the load. Several studies also confirmed that the use of Puddu plates had a higher complication rate (37.7-55%)^5–7 than using locking or non-locking T-plates (1.9-8.6%).^8–10 Additionally, the recent finite element analysis demonstrated that the Tomofix plate produces superior stability for bony fixation in MOWHTO procedures than the Puddu plate.¹¹ Therefore, type of implant had the significant effect to complication rate. Because of our concern about the disadvantages of bone substitute¹²,¹³ (including delayed incorporation into bone, soft tissue irritation, and infections) and the donor site morbidity from harvesting iliac bone graft, we purposed the technique of using a Tomofix plate without interposition materials, which has been previously recommended in several studies.^14–18 Our study shows satisfactory outcome with the same bone healing time as using bone substitute (within 8-12 weeks).¹⁹ Finally, we appreciate the results of your technique that used tricalcium phosphate substitute alone and hope that results of it would be published for the benefit of other readers.