Association between clinical symptoms and lateral thrust 12 months after high tibial osteotomy

Abstract

[Purpose] This study aimed to assess the correlation between lateral thrust and clinical symptoms after high tibial osteotomy and determine lower limb alignments that may decrease lateral thrust. [Participants and Methods] We included 54 patients (73 knees) who underwent high tibial osteotomy. Clinical symptoms, including the Japanese Orthopaedic Association score and the hip-knee-ankle angle measured via radiography, were assessed 12 months postoperatively. Lateral thrust was measured using three-dimensional motion analyses. Logistic regression was used to calculate the cut-off values with good Japanese Orthopaedic Association score and lateral thrust as dependent variables and both lateral thrust and hip-knee-ankle angle as independent variables. [Results] The lateral thrust cut-off was 3.1° (sensitivity: 0.83; specificity: 0.74; area under the curve: 0.76), while that of the hip-knee-ankle angle was 1.9° of valgus (sensitivity: 0.71; specificity: 0.81; area under the curve: 0.72). [Conclusion] Good clinical outcomes after high tibial osteotomy can be expected with a lateral thrust of ≤3.0°, indicating that the target hip-knee-ankle angle should be 2.0° valgus. In cases where valgus alignment is insufficient, lateral thrust may develop, which should be assessed using gait analysis.

Keywords: Alignment; Gait; High tibial osteotomy.

Fig. 1.

Flowchart for selection of research participants. We included 320 patients who underwent HTO for KOA with Kellgren & Lawrence classification grade I or higher at our hospital between 2017 and 2021. Patients who did not provide their informed consent to participate in the study; those with a history of surgery on lower limbs (the measuring limb), a musculoskeletal or neurological disease that inhibited them from walking alone for >10 m, or a ligament injury and joint instability; and highly obese patients with a body mass index (BMI) of >35 were excluded. HTO: high tibial osteotomy; KOA: knee osteoarthritis.

Fig. 2.

Cut-off values for LT with low impact on JOA score failure. Logistic regression analysis with JOA as the dependent variable showed a cut-off value for LT of 3.1° (sensitivity: 0.83; specificity: 0.74; AUC: 0.76). LT: lateral thrust: JOA: Japanese Orthopaedic Association.

Fig. 3.

Cut-off value of HKA angle at which LT does not appear. The logistic regression analysis revealed a significant positive association with HKA, with a cut-off value of −1.90° (sensitivity: 0.69; specificity: 0.83; AUC 0.71). HKA: hip–knee–ankle; LT: lateral thrust; AUC: area under the curve.