Patellofemoralleddet

Patellofemoralleddet is the articulation between the patella (kneecap) and the femoral trochlea (groove at the distal femur). It is a synovial joint formed by the posterior surface of the patella and the trochlear cartilage of the femur, and it is integral to knee extension mechanics. The joint is stabilized by the quadriceps tendon, patellar tendon, medial and lateral retinacula, and the medial patellofemoral ligament (MPFL).

Functionally, the patellofemoral joint increases the mechanical advantage of the quadriceps by acting as a pulley, distributes compressive forces across the anterior knee, and guides patellar tracking during flexion and extension. Patellar tracking depends on bone geometry (trochlear depth, patellar shape), soft tissue balance (muscle strength, retinacular tension), and lower-limb alignment.

Clinically, the patellofemoral joint is commonly involved in disorders such as patellofemoral pain syndrome, chondromalacia patellae, and patellar instability or dislocation. Contributing factors include muscle imbalance (particularly weakened vastus medialis obliquus), patellar malalignment, trochlear dysplasia, patella alta, and increased Q-angle. Symptoms often include anterior knee pain, crepitus, swelling, and episodes of giving way.

Diagnosis is based on history and physical examination, with imaging (weight-bearing radiographs, skyline views, and MRI) used to assess alignment, cartilage, and soft tissues. Management typically begins with conservative measures—activity modification, targeted physiotherapy, patellar taping or bracing, and orthotics—while refractory or structural cases may require surgical options such as MPFL reconstruction, realignment procedures, or trochleoplasty.