Patella Alta: Understanding, Untreated Consequences, and Management

What Happens if Patella Alta Goes Untreated?

Patella alta, characterized by an abnormally high-riding kneecap, can lead to a cascade of biomechanical issues if left untreated, significantly increasing the risk of chronic pain, instability, and degenerative changes within the knee joint.

Understanding Patella Alta

Patella alta is a condition where the patella (kneecap) sits higher than its normal anatomical position relative to the trochlear groove of the femur (thigh bone). This superior displacement is typically measured using radiographic indices, such as the Insall-Salvati ratio or Blackburne-Peel ratio.

Anatomy and Biomechanics: In a healthy knee, the patella glides smoothly within the trochlear groove during knee flexion and extension, distributing forces evenly across its articular cartilage. This engagement provides bony stability and optimizes the mechanical advantage of the quadriceps muscle. With patella alta, the patella enters the trochlear groove later in knee flexion. This delayed engagement means the patella is less stable in early flexion and can experience altered contact pressures and tracking issues, which forms the basis of many untreated consequences.

Causes: While often congenital or developmental, patella alta can also be influenced by factors such as quadriceps muscle imbalances (e.g., tightness of the rectus femoris), patellar tendon length, or previous knee trauma.

The Cascade of Untreated Patella Alta: Immediate and Long-Term Consequences

If patella alta is left unaddressed, the altered biomechanics exert detrimental effects on the patellofemoral joint and surrounding structures, leading to a progressive decline in knee health and function.

• Altered Patellar Tracking and Increased Stress: The primary consequence is improper patellar tracking. Because the patella sits high, it may not engage the trochlear groove effectively, particularly in the early phases of knee flexion. This often leads to the patella tracking laterally (towards the outside of the knee). This abnormal movement increases localized stress and pressure on specific areas of the articular cartilage, rather than distributing it evenly.
• Patellofemoral Pain Syndrome (PFPS): This is one of the most common presenting symptoms. The increased, uneven pressure on the articular cartilage, coupled with potential irritation of the retinaculum and synovial tissues, results in anterior knee pain. This pain is typically exacerbated by activities that load the patellofemoral joint, such as climbing or descending stairs, squatting, running, or prolonged sitting with the knees bent ("movie-goer's sign").
• Increased Risk of Patellar Dislocation/Subluxation: The high-riding patella has less bony constraint from the trochlear groove, especially in knee extension and early flexion. This significantly increases the risk of the patella partially (subluxation) or fully (dislocation) slipping out of the groove, usually laterally. Each episode can damage the articular cartilage and supporting ligaments, making subsequent events more likely.
• Chondromalacia Patellae and Osteoarthritis: The chronic, abnormal loading and friction on the patellar and femoral articular cartilage lead to its softening and degeneration, a condition known as chondromalacia patellae. Over time, this progressive cartilage damage can advance to full-blown patellofemoral osteoarthritis, characterized by joint space narrowing, bone spurs (osteophytes), and chronic pain, significantly limiting mobility and quality of life.
• Quadriceps Dysfunction and Weakness: The altered mechanics can lead to inhibition and weakness of the quadriceps muscles, particularly the vastus medialis obliquus (VMO), which is crucial for medial patellar stabilization. This weakness further exacerbates tracking issues and can lead to a vicious cycle of pain, disuse, and muscle atrophy.
• Compensatory Movement Patterns: To avoid pain or instability, individuals may adopt compensatory movement patterns. This could involve altering gait, avoiding deep knee flexion, or shifting weight, potentially leading to secondary issues in the hip, ankle, or even the lower back due to altered kinetic chain mechanics.
• Impact on Activity and Quality of Life: Untreated patella alta can progressively limit participation in physical activities, sports, and even daily tasks requiring knee flexion, such as walking, stair climbing, or standing from a seated position. This can lead to a sedentary lifestyle, contributing to other health concerns and a reduced overall quality of life.

Diagnosis and Management Principles

Diagnosis of patella alta typically involves a thorough clinical examination, including palpation, range of motion assessment, and specific tests for patellar mobility and tracking. Radiographic imaging (X-rays, MRI) is crucial to confirm the diagnosis and assess the degree of patellar elevation and any associated cartilage damage.

Conservative Management: Early and consistent conservative management is the cornerstone of treatment for patella alta and its related symptoms. This typically includes:

• Physical Therapy: A structured program focusing on strengthening the quadriceps (especially VMO), hip abductors and external rotators (e.g., gluteus medius), and core muscles. Flexibility exercises for tight structures like the quadriceps, hamstrings, and IT band are also vital. Proprioceptive training and gait analysis may also be incorporated.
• Activity Modification: Temporarily reducing or avoiding activities that aggravate symptoms, such as deep squats, lunges, or prolonged knee flexion.
• Orthotics/Bracing: Custom or off-the-shelf orthotics can help address foot biomechanics that may contribute to knee issues, while patellar stabilizing braces can offer support during activities.

Surgical Intervention: In cases of severe patellar instability (recurrent dislocations) that fail to respond to comprehensive conservative treatment, surgical options may be considered. These can range from soft tissue procedures (e.g., medial patellofemoral ligament reconstruction) to bony procedures (e.g., tibial tubercle osteotomy) aimed at realigning the patella.

The Importance of Early Intervention

The progressive nature of patella alta's complications underscores the importance of early diagnosis and intervention. Proactive management can significantly reduce the risk of developing chronic pain, degenerative arthritis, and recurrent instability. By addressing the biomechanical issues early, individuals can preserve knee joint health, maintain an active lifestyle, and prevent the severe long-term consequences associated with untreated patella alta.