J Korean Fract Soc.  2024 Jul;37(3):125-136. 10.12671/jkfs.2024.37.3.125.

Restoration of Lateral Tibial Plateau Widening and Articular Depression Is Necessary to Prevent Valgus Deformities after Arthroscopic Reduction and Internal Fixation in AO/OTA 41.B2 or B3 Fractures

• Kim JH
• Kim KI
• Lee SH
• Son G
• Kim MS

• KMID: 2558296
• DOI: http://doi.org/10.12671/jkfs.2024.37.3.125

Abstract

Purpose
This study examined the factors affecting valgus deformities after arthroscopic reduction and internal fixation (ARIF) in lateral joint-depression tibial plateau fractures.
Materials and Methods
Patients with lateral joint-depression tibial plateau fractures treated with ARIF were assessed retrospectively. The radiological evaluations included the articular depression distance (ADD) and the lateral plateau widening distance (LPWD) on preoperative and postoperative computed tomography. A postoperative valgus deformity was defined as valgus malalignment (mechanical axis ≥3°) and valgus deviation (Δmechanical axis of the operated knee from the healthy knee of ≥5°). Subgroup analyses based on a postoperative valgus deformity were performed to compare the clinical outcomes, including the range of motion, patient-reported outcomes measures, and failure and osteoarthritis progression. Furthermore, factors affecting the postoperative mechanical and Δmechanical axes were assessed.
Results
Thirty-nine patients were included with a mean follow-up of 44.6 months (range, 24-106 months). Valgus malalignment and valgus deviation were observed after ARIF in 10 patients (25.6%) and five patients (12.8%), respectively. The clinical outcomes were similar in patients with and without a postoperative valgus deformity. On the other hand, lateral compartment osteoarthritis progression was significantly higher in the valgus deformity group than in the non-valgus deformity group (valgus malalignment group: 50.0% vs 6.9%, p=0.007; valgus deviation group: 60.0% vs 11.8%, p=0.032). One patient with valgus deformity underwent realignment surgery at postoperative five years. The preoperative ADD and postoperative LPWD were significantly associated with the postoperative mechanical (both, p<0.001) and Δmechanical (ADD, p=0.001; LPWD, p=0.025) axes. Moreover, the lateral meniscectomized status during ARIF was significantly associated with the Δmechanical axis (p=0.019).
Conclusion
Osteoarthritis progression was highly prevalent in patients with postoperative valgus deformity. Thus, the restoration of lateral plateau widening and articular depression and preservation of the meniscus are necessary to prevent a valgus deformity after ARIF in lateral joint-depression tibial plateau fractures.

Keyword

Tibia plateau fracture; Schatzker type; Genu valgum; Osteoarthritis; Arthroscopy; Internal fixation; Plateau widening; Plateau depression