Introduction

A systematic review by D'Souza [1] shows that certain parameters are associated with an increased risk for the occurrence and progression of knee osteoarthritis (KOA). This can be shown in the gait pattern by means of three-dimensional gait analysis. Parameters such as peal KAM (maximum knee adduction moment), KAM impulse or varus thrust are values that are analysed in the gait pattern and can be associated with KOA. Furthermore, the forces in the medial-lateral compartment can be calculated from the data of the three gait analyses using musculoskeletal modelling. Changes in the gait pattern can influence these parameters (KAM). Clinical movement analysis can provide feedback on the altered gait pattern and indicate whether the load is actually changed as a result. Changes such as reduced gait speed, reduced cadence, reduced flexion in the stance phase as well as the reduction of hip adduction moment contribute to the lowering of the increased adduction moment in medial knee joint arthrosis [2][3][4][5][6]. Lateral raising of the edge of the shoe or orthoses can also have a positive influence on the load situation in the knee joint. In particular, the first peak in the KAM can be reduced by raising the lateral edge of the shoe in patients with KOA [7].

Content

Using the inverse approach, the load in the medial and lateral compartments can be calculated by means of musculoskeletal modelling. Zhao et al. [8] demonstrated that KAM correlates highly with the contact force in the medial compartment and the ratio of medial to total force during walking. Van Rossom et.al. [9] used musculoskeletal modelling to show that tibial slop, frontal leg alignment and rotational malalignment at the tibia contribute to changes in knee joint forces. A combination of a varus malalignment and an internal rotation malalignment further increases the KAM. However, if the varus malalignment is combined with external rotation, the KAM is normalised. Vice versa for the valgus malalignment.

These observations were also made by the research group around Farr et.al. [10 ] in adolescents who had a valgus deformity in the knee. In patients with a valgus deformity, the tibial rotation has a major influence on the KAM in addition to the frontal deformity. Although the frontal leg axis could be corrected by correcting the axis with tension band plating, the postoperative result of the 3-dimensional gait analysis showed a much higher adduction moment in those patients with a reduced tibial external rotation than in the normal group [11]. Preoperatively, the group with valgus malalignment and rotational malalignment showed an almost normal KAM. In contrast, the valgus-only group showed a greatly reduced KAM.

Musculoskeletal modelling can also be used to investigate which exercises in the rehabilitation phase place more strain on the medial or lateral compartment and thus create targeted planning of the therapy programme.

The three-dimensional clinical gait analysis makes it possible to gain an insight into the prevailing forces on the knee joint and shows an objective picture of the load situation. With the additional use of musculoskeletal modelling, it is also possible to analyse the load distribution in the knee joint more precisely. However, the creation of a patient-specific biomechanical model is currently still quite time-consuming.

References

[1] D’Souza u. a., „Are Biomechanics during Gait Associated with the Structural Disease Onset and Progression of Lower Limb Osteoarthritis?“

[2] Guo, Axe, und Manal, „The Influence of Foot Progression Angle on the Knee Adduction Moment during Walking and Stair Climbing in Pain Free Individuals with Knee Osteoarthritis“.

[3] Mills, Hunt, und Ferber, „Biomechanical Deviations during Level Walking Associated with Knee Osteoarthritis“.

[4] Mündermann u. a., „Potential Strategies to Reduce Medial Compartment Loading in Patients with Knee Osteoarthritis of Varying Severity“.

[5] Chang u. a., „The Relationship between Toe-out Angle during Gait and Progression of Medial Tibiofemoral Osteoarthritis“.

[6] Andrews u. a., „Lower Limb Alignment and Foot Angle Are Related to Stance Phase Knee Adduction in Normal Subjects“.

[7] Fantini Pagani, Hinrichs, und Brüggemann, „Kinetic and Kinematic Changes with the Use of Valgus Knee Brace and Lateral Wedge Insoles in Patients with Medial Knee Osteoarthritis“.

[8] Zhao u. a., „Correlation between the Knee Adduction Torque and Medial Contact Force for a Variety of Gait Patterns“.

[9] Van Rossom u. a., „The Influence of Knee Joint Geometry and Alignment on the Tibiofemoral Load Distribution“.

[10] Farr u. a., „Functional and radiographic consideration of lower limb malalignment in children and adolescents with idiopathic genu valgum“.

[11] Farr u. a., „Rotational gait patterns in children and adolescents following tension band plating of idiopathic genua valga“.