Why Gait Assessment is Critical in Knee Varus Deformity
Gait assessment in individuals with knee varus deformity is essential because abnormal loading patterns during walking directly cause progressive cartilage damage, predict surgical complexity, and identify biomechanical dysfunction that impacts both treatment planning and long-term outcomes.
Abnormal Mechanical Loading During Gait Drives Disease Progression
Varus deformity creates excessive medial compartment forces during weight-bearing that accelerate cartilage destruction. As the varus angle increases, there is significant increase in peak stress concentration in the medial compartment, with varus angles exceeding 6° associated with substantially higher risk of cartilage damage 1.
The mechanical axis shifts medially with increasing varus deformity, causing abnormal force distribution across the knee joint during each step of the gait cycle 1.
Varus thrust—a dynamic worsening of varus alignment visible during the stance phase of gait—represents a particularly destructive biomechanical pattern that indicates severe medial compartment overload and is associated with accelerated disease progression 2.
Gait Analysis Reveals Functional Impairment Beyond Static Measurements
Static radiographic measurements alone cannot capture the dynamic mechanical dysfunction that occurs during walking. Gait observation and analysis systems assess the actual loading patterns, step patterns, and compensatory mechanisms patients develop 3.
Varus thrust during gait is present in approximately 22% of patients with knee osteoarthritis and represents a dynamic instability pattern not visible on standing radiographs 2.
Patients with varus thrust demonstrate 3.6-fold higher risk of moderate-to-severe low back pain, indicating that abnormal knee mechanics during gait create compensatory loading patterns throughout the kinetic chain 2.
Gait Assessment Guides Surgical Planning and Predicts Complexity
The degree of varus deformity correlates with operative time, technical difficulty, and residual alignment after surgery. Patients with severe varus deformity (≥20°) require an average of 30 minutes longer operative time and demonstrate greater variability in postoperative outcomes 4.
Nearly half (48%) of patients with mild coronal deformity (stage I) can still have severe intra-articular disease (grade C), meaning static alignment measurements underestimate surgical complexity without functional gait assessment 5.
One in seven patients with varus osteoarthritis has extra-articular deformity that requires different surgical approaches, which may not be apparent without comprehensive evaluation including gait analysis 5.
Gait Evaluation Identifies Specific Biomechanical Targets for Intervention
Gait analysis systems can diagnose pressure areas, identify abnormal walking patterns, and evaluate therapeutic interventions in patients with lower extremity deformities 3.
Assessment of walking ability and gait patterns helps quantify functional consequences of deformity on mobility and quality of life, guiding decisions about timing and type of intervention 3.
Correcting foot balance and eliminating areas of abnormal weight-bearing during gait reduces pain and improves function, demonstrating the therapeutic value of addressing gait abnormalities 3.
Common Pitfalls to Avoid
Do not rely solely on standing radiographs to assess severity—static images miss dynamic instability patterns like varus thrust that significantly impact prognosis 2.
Do not assume mild deformity angles indicate simple surgical cases—nearly half of patients with limited coronal deformity have severe intra-articular disease requiring complex reconstruction 5.
Do not ignore the kinetic chain—abnormal knee mechanics during gait create compensatory patterns affecting the spine and other joints, requiring comprehensive biomechanical assessment 2.
Recognize that varus deformity leads to medial soft tissue contractures, lateral soft tissue lengthening, and potential bone defects that all influence surgical approach and cannot be fully appreciated without understanding how the patient actually walks 6.