Difference in the anterior displacement of the tibial tuberosity relative to the proximal tibial fragment between opening wedge and closed wedge high tibial osteotomies.

Introduction: This study aimed to investigate the anterior-posterior (AP) displacement of the tibial tuberosity (TT) and to assess the difference between closed wedge and opening wedge high tibial osteotomies (OWHTO and CWHTO).

Methods: One hundred consecutive knees with osteoarthritis that underwent OWHTO (50 knees) or CWHTO (50 knees) were investigated retrospectively. The femorotibial angle (FTA) was measured on AP radiographs of the knee. AP displacement of the TT, posterior tibial slope (PTS), the modified Blackburne-Peel index (mBPI), and the modified Caton-Deschamps index (mCDI) were measured on lateral radiographs of the knee.

Results: Patients had a mean correction angle of 12.58 ± 2.84° and 18.98 ± 5.14° (P < 0.001), with a mean AP displacement of TT of 0.84 ± 2.66 mm and 7.78 ± 3.41 mm (P < 0.001) in OWHTO and CWHTO, respectively. The AP displacement of the TT per correction of 1° was significantly greater in CWHTO than in OWHTO (P < 0.001). A significant correlation was found between the correction angle and AP displacement of the TT in CWHTO (r = -0.523, P < 0.001), but not in OWHTO. The change of PTS per correction of 1° was significantly greater in OWHTO than in CWHTO (P < 0.001). The changes of mBPI and mCDI per correction of 1° were significantly greater in CWHTO than in OWHTO (P < 0.001 and P < 0.001, respectively).

Conclusions: There was greater anterior displacement of the TT in CWHTO than in OWHTO, which was correlated with the correction angle. The results suggested that CWHTO would be better than OWHTO when a concomitant anteriorization of TT is required.