What is Patellar Tracking?
Patellar tracking refers to the motion of the patella (kneecap) relative to the femoral groove during knee flexion and extension, and abnormalities in this tracking pattern (maltracking) are associated with patellofemoral pain and dysfunction in geriatric patients with osteoarthritis. 1
Biomechanical Definition
The patella functions as a complex lever that magnifies the moment arm of the knee extensor mechanism, with its contact area shifting along a proximodistal axis through the knee's range of motion 2
During normal tracking, the patella translates medially in early knee flexion and then shifts laterally as flexion progresses 1
The tracking pattern results from an interplay between quadriceps muscle forces, patellofemoral ligaments, trochlear groove geometry, and the quadriceps angle 2
Clinical Significance in Geriatric Osteoarthritis
Abnormal patellar tracking (maltracking) can increase patellofemoral contact pressures, potentially accelerating cartilage degeneration and causing anterior knee pain 3
In geriatric patients with suspected osteoarthritis, patellar maltracking often manifests as anterior knee pain, crepitus, and functional limitations with activities like stair climbing or rising from chairs 4
The American College of Radiology emphasizes that functional limitations and pain should be the primary focus of evaluation, rather than tracking abnormalities alone, as many elderly patients have asymptomatic tracking variations 4
Assessment Considerations
Accurate measurement of patellar tracking remains challenging, as results are affected by coordinate system definitions, muscle loading patterns, knee motion range and direction, and measurement technique (static versus dynamic) 1
The American College of Radiology recommends that if radiographs show only joint effusion but pain persists, MRI without IV contrast may be indicated for detecting underlying pathology 4
A critical pitfall is overreacting to tracking abnormalities or crepitus alone without considering functional status and pain severity, which can lead to unnecessary imaging and interventions 4
Management Implications
When patellar maltracking contributes to symptomatic osteoarthritis, the American Geriatrics Society recommends first-line non-pharmacological management including quadriceps strengthening exercises, which directly improve patellar tracking mechanics 5, 4
Orthotic devices such as patella tape or knee bracing may provide mechanical support to optimize tracking in patients with significant functional impairment 5
The American Academy of Orthopaedic Surgeons recommends tibiofemoral knee braces when disease significantly impacts ambulation, joint stability, or pain, as these can influence patellar tracking mechanics 6