Clinical and Radiological Outcomes of Double-Level Osteotomy Versus Open-Wedge High Tibial Osteotomy for Bifocal Varus Deformity

Abstract

Background: In bifocal varus deformity, double-level osteotomy (DLO) is advocated to treat lower limb alignment to prevent an adverse increase in joint line obliquity.

Purpose/hypothesis: The purpose of this study was to compare the clinical and radiological results after DLO and open-wedge high tibial osteotomy (OWHTO) in patients with combined varus deformity. It was hypothesized that DLO would improve clinical results without increasing the complication rate compared with OWHTO.

Study design: Cohort study; Level of evidence, 3.

Methods: Inclusion criteria were medial tibiofemoral compartment pain, varus knee deformity with an abnormal medial proximal tibial angle <84° and a lateral distal femoral angle >90°, a functional anterior cruciate ligament, failure of nonoperative treatment, and a minimum 2-year follow-up with all clinical and radiological data. The rate of return to work or sports; the Knee injury and Osteoarthritis Outcome Score (KOOS); the University of California, Los Angeles (UCLA) activity score; and patient satisfaction were assessed at a minimum of 2 years of follow-up. Statistical comparison of the 2 groups was made using the chi-square or Student t test.

Results: A total of 69 consecutive patients were analyzed, of whom 38 underwent OWHTO and 31 underwent DLO surgery. A significant between-group difference was found for all radiological parameters; in particular, there was less joint line obliquity after DLO compared with OWHTO (1.7° vs 5.6°; P < .001). DLO provided better outcomes compared with OWHTO regarding the UCLA score (4.3 vs 6.7; P < .001) and patient satisfaction (2.6 vs 3.9; P < .001), but no significant difference in KOOS or return to work or sports was observed. The OWHTO group had more hinge fractures than the DLO group (34.2% vs 12.9%; P < .001).

Conclusion: For combined tibial and femoral varus deformity, DLO produced more physiologic joint line obliquity with slightly improved UCLA and patient satisfaction scores. A greater incidence of hinge fracture was observed after isolated OWHTO compared with DLO due to a larger tibial correction; however, this had little effect on clinical results at the 2-year follow-up.

Keywords: clinical outcome; complications; double-level osteotomy; joint line obliquity; open-wedge high tibial osteotomy.

Figure 1.

Flowchart of patient inclusion in the study. DLO, double-level osteotomy; OWHTO, open-wedge high tibial osteotomy.

Figure 2.

Measurements as shown on preoperative weightbearing long-leg and sagittal view radiographs. (A) Hip-knee-ankle angle (HKA), medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA). (B) Joint line convergence angle (in yellow), joint line obliquity (in white). (C) Posterior proximal tibial angle.

Figure 3.

Bilateral double-level osteotomy in 2 sessions. (A) Image obtained in a patient with a combined preoperative femoral and tibial varus deformity on both sides. (B) First, a lateral closing distal femoral osteotomy was performed. (C) Then, the mechanical axis still passing through the medial tibial plateau was shifted laterally by the open-wedge high tibial osteotomy, (D) with the goal to obtain a mechanical axis crossing the tibial plateau from 50% to 55% of the medial tibial border. (E and F) Postoperative results showed a joint line obliquity parallel to the ground with a bilateral neutral mechanical axis.

Figure 4.

Postoperative hinge fracture after isolated OWHTO in a patient with both femoral and tibial varus deformity. (A) Image obtained in a patient with a combined preoperative femoral and tibial varus deformity. (B) An isolated OWHTO was performed with an overcorrection at the tibial side resulting in a joint line obliquity of 4° with a perioperative hinge fracture (asterisk on the anteroposterior view). An iatrogenic excessive slope can also be seen on the lateral view. OWHTO, open-wedge high tibial osteotomy.