Polvilumpu

Polvilumpu, or patella, is the small, flat bone located at the front of the knee joint. It lies within the quadriceps tendon and connects inferiorly to the tibia via the patellar tendon. The posterior surface carries articular cartilage and articulates with the femur in the trochlear groove, forming the patellofemoral joint. It is the largest sesamoid bone in the human body.

Anatomically, the patella serves as part of the knee’s extensor mechanism by increasing the leverage of the quadriceps muscle during straightening of the leg. It is typically a single bone, though it can show normal variations such as an accessory piece at birth that fuses with the main bone later. The patellofemoral joint allows smooth gliding of the patella over the femur during knee movement.

Functionally, the patella improves the quadriceps’ mechanical advantage, enhancing knee extension power and protecting the knee joint from direct impact. By increasing the angle of pull of the quadriceps tendon, it reduces wear on the tendon itself and contributes to efficient movement.

Common conditions affecting the polvilumpu include patellofemoral pain syndrome, patellar dislocation or subluxation, and patellar tendonitis (jumper’s knee). Fractures of the patella can occur after direct trauma. Diagnosis typically involves clinical examination and imaging, with X-ray as a primary tool and MRI or CT used for detailed assessment.

Treatment ranges from conservative approaches—rest, ice, nonsteroidal anti-inflammatory drugs, and physical therapy focusing on quadriceps and hip stabilizers—to bracing or taping. In dislocations, fractures, or persistent instability, surgical options such as realignment procedures or patellar tendon repair may be considered. Rehabilitation usually aims to restore strength and proper patellar tracking to prevent recurrence.