Patella alta is a condition where the kneecap, or patella, sits unusually high within the thigh bone’s groove. This elevated position affects how the knee functions and can contribute to discomfort or instability. Understanding this anatomical variation is important for those with related knee issues.
What Patella Alta Is
The patella, a triangular bone at the front of the knee joint, connects to the quadriceps tendon above and the patellar tendon below, attaching to the shinbone (tibia). Normally, it glides within a shallow indentation on the femur, called the trochlear groove, as the knee bends and straightens.
In patella alta, the kneecap rests higher than its typical position in this groove. This altered position prevents the patella from fully engaging with the deeper, more stable part of the groove, especially during initial knee flexion. This reduces bony stability, making the kneecap more prone to shifting, instability, and increased joint pressure.
Signs and Causes of Patella Alta
Common symptoms of patella alta include pain around the kneecap, a feeling of instability, or the sensation of the knee “giving way.” Clicking or popping sounds during knee movement are also common. These symptoms frequently worsen with activities involving significant knee bending, such as stairs, squatting, or prolonged sitting.
Patella alta is often a developmental or congenital condition, resulting from an abnormally long patellar tendon that positions the kneecap higher. Genetic predispositions can play a role in this anatomical variation. It can also be acquired due to factors like repetitive stress, chronic conditions such as patellar tendinitis, or previous knee injuries or surgeries, such as a patellar tendon rupture.
Diagnosis and Management of Patella Alta
Diagnosing patella alta involves a thorough evaluation by a healthcare professional. A physical examination assesses the knee’s range of motion, stability, and patellar tracking. Specific tests may evaluate the kneecap’s position and movement.
Imaging studies confirm the diagnosis. X-rays, particularly a lateral view of the knee taken at 30-degree flexion, are commonly used. Healthcare providers measure patellar height using specific ratios, such as the Insall-Salvati ratio (ISI), where an ISI greater than 1.2 generally indicates patella alta. An MRI may also be ordered for detailed images of soft tissues like cartilage and tendons, assessing any associated damage.
Conservative methods are often the first treatment. Physical therapy is recommended, focusing on strengthening quadriceps, hamstring, and gluteal muscles to improve knee stability and alignment. Bracing or taping the patella can provide external support. Pain management, often involving non-steroidal anti-inflammatory drugs (NSAIDs), helps alleviate discomfort.
If conservative treatments do not provide sufficient relief, or for cases with severe instability or persistent pain, surgical intervention might be considered to realign the patella.