Comparison of the outcomes between two different target points after open wedge high tibial osteotomy: The Fujisawa point versus the lateral tibial spine.

BACKGROUND

The purpose of this study was to compare the clinical, radiographic and arthroscopic outcomes after open wedge high tibial osteotomy (OWHTO) aiming either at the Fujisawa point (group F) or the lateral tibial spine (LTS, group L).

METHODS

Between January 2011 and May 2017, 89 cases underwent implant removal procedures with second-look arthroscopy at 19.8 months after OWHTO with first-look arthroscopy. Among them, 24 and 65 cases were enrolled in groups F and L, respectively. Outcomes included clinical (evaluated using the Western Ontario and McMaster Universities Osteoarthritis index and the International Knee Documentation Committee subjective score), radiographic (observation of the mechanical axis (MA) and tibial slope), and arthroscopic (including chondral lesions of the medial femoral condyle (MFC), trochlea, and patella scored according to the International Cartilage Repair Society grading) measures, investigated at index surgery and implant removal surgery. Outcomes were compared between two groups.

RESULTS

Preoperative clinical characteristics and postoperative outcomes were similar between both groups. The mean postoperative MA was significantly lower in group F compared with group L (-3.9° vs. -1.6°, respectively; P < 0.001). Similar MFC cartilage grading changes from index surgery to second look surgery were shown; however, further progression of patellofemoral grading was shown in group F.

CONCLUSIONS

OWHTO aimed at the LTS has similar clinical outcomes to Fujisawa point. Surgery aimed at the LTS was slightly less corrected. Targeting the LTS could be an option after consideration of joint geometry and patellofemoral joint problems.