Comparative study of medial opening-wedge high tibial osteotomy using 2 different implants.

PURPOSE

The purpose of this study was to perform a retrospective clinical and radiographic evaluation after opening-wedge high tibial osteotomy (HTO) using a short spacer plate (Aescula; B. Braun Korea, Seoul, South Korea) and rigid long plate (TomoFix plate; Mathys, Bettlach, Switzerland) at follow-up 2 years postoperatively.

METHODS

We performed 94 opening-wedge HTOs with the Aescula plate (group I) and 92 HTOs with the TomoFix plate (group II). Patients underwent clinical and radiographic evaluations preoperatively and at 2 years postoperatively. Clinical evaluations were performed with Knee Society scores. Radiographic analysis included the mechanical tibiofemoral angle (mTFA) and the slope of the tibia angle with preoperative and postoperative full weight-bearing anteroposterior whole-leg views, as well as anteroposterior, lateral, and Merchant views of the knee. We measured the mTFA. In addition, we evaluated the complications in each group. The follow-up period was 2 years.

RESULTS

At follow-up 2 years postoperatively, we observed an overall complication rate of 38% in group I and 26% in group II (P = .083). We found plate-related complication rates of 20% in group I and 9% in group II (P = .039). Plate-related complications included loss of correction, fracture of the tibial plateau, screw failure, malunion, and fracture of the lateral cortical bone. The mean mTFA was -6.0° ± 3.2° in group I and -4.6° ± 2.8° in group II preoperatively (P = .262). The mean mTFA was 1.0° ± 3.1° in group I and 1.5° ± 2.3° in group II at the latest follow-up (P = .034). In group I, the mean Knee Society knee score and function score were 60.0 ± 12.9 and 57.9 ± 26.8, respectively, preoperatively. They improved to 92.1 ± 8.1 and 89.0 ± 15.1, respectively, at follow-up (P = .001 and P = .001, respectively). In group II, the mean Knee Society knee score and function score were 57.5 ± 14.8 and 57.4 ± 22.1, respectively, preoperatively. They improved to 95.5 ± 5.4 and 95.0 ± 7.6, respectively, at follow-up (P = .001 and P = .001, respectively). In addition, the mean postoperative knee score and function score in group II were higher than those in group I (P = .001 and P = .001, respectively).

CONCLUSIONS

We have shown a high plate-related complication rate and a significant loss of correction during a short-term follow-up period (2 years) after opening-wedge HTO using the new short spacer HTO plate compared with the rigid long plate.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.