Deviated Patella: Understanding Maltracking, Causes, Symptoms, and Treatment

What is a Deviated Patella?

A deviated patella, often referred to as patellar maltracking, describes a condition where the kneecap moves abnormally within the trochlear groove of the thigh bone (femur) during knee flexion and extension, leading to pain and dysfunction.

Understanding the Patella and Its Role

The patella, commonly known as the kneecap, is a unique, triangular-shaped bone embedded within the quadriceps tendon. It serves as a crucial component of the knee extensor mechanism. As you bend and straighten your knee, the patella glides smoothly within a V-shaped groove at the end of the femur, called the trochlear groove.

The primary functions of the patella include:

• Leverage: It acts as a fulcrum, increasing the mechanical advantage of the quadriceps muscles, allowing them to exert greater force on the lower leg for extension.
• Protection: It shields the underlying knee joint from direct impact.
• Force Distribution: It helps distribute forces across the knee joint during movement.

For optimal knee function and pain-free movement, the patella must track precisely within its groove.

What Constitutes a "Deviated Patella"?

A "deviated patella" occurs when the kneecap does not follow its normal, central path within the trochlear groove. Instead, it shifts excessively to one side, most commonly laterally (outward), or, less frequently, medially (inward). This abnormal movement is known as patellar maltracking or patellofemoral malalignment.

Unlike a patellar dislocation, where the kneecap completely comes out of its groove, deviation implies a persistent, subtle misalignment or an irregular gliding pattern that can cause chronic irritation, inflammation, and pain within the patellofemoral joint. Over time, this can lead to patellofemoral pain syndrome (PFPS), sometimes called "runner's knee" or "jumper's knee," and contribute to accelerated cartilage wear.

Common Causes of Patellar Deviation (Patellar Maltracking)

Patellar deviation is rarely due to a single cause; it typically results from a combination of factors that disrupt the delicate balance required for proper patellar tracking. These factors can be broadly categorized as:

• Muscular Imbalances:
  • Weakness of the Vastus Medialis Obliquus (VMO): The VMO, an inner part of the quadriceps, is crucial for pulling the patella medially. If weak relative to the stronger vastus lateralis, the patella can be pulled outward.
  • Tightness of the Lateral Structures: A tight iliotibial (IT) band or lateral retinaculum (a band of connective tissue on the outer side of the patella) can exert an excessive pull, drawing the patella laterally.
  • Weak Hip Abductors and External Rotators: Muscles like the gluteus medius and minimus help stabilize the pelvis and femur. Weakness here can lead to excessive hip adduction and internal rotation during movement, causing the femur to rotate internally under the patella, effectively pushing the patella outward.
• Anatomical Factors:
  • Patella Alta: A high-riding patella, meaning it sits higher than normal in the trochlear groove, making it less stable and more prone to tracking issues.
  • Trochlear Dysplasia: A shallow or poorly formed trochlear groove on the femur provides less bony containment for the patella, increasing its tendency to deviate.
  • Increased Q-Angle: The Q-angle (quadriceps angle) is the angle formed by a line from the anterior superior iliac spine (ASIS) through the center of the patella, and a line from the center of the patella through the tibial tuberosity. A larger-than-normal Q-angle (common in individuals with wider hips) can increase the lateral pull on the patella.
  • Foot Pronation (Flat Feet): Excessive inward rolling of the foot during gait can lead to internal rotation of the tibia and femur, contributing to patellar maltracking.
• Biomechanical Factors:
  • Poor Movement Patterns: Incorrect technique during activities like squatting, lunging, or running, often characterized by knee valgus (knees caving inward), can exacerbate patellar deviation.
  • Overuse: Repetitive stress from activities that involve repeated knee bending (e.g., cycling, running, jumping) can irritate the patellofemoral joint if underlying biomechanical issues are present.
• Trauma: A direct blow to the knee or a twisting injury can sometimes disrupt patellar alignment or the soft tissue structures supporting it.

Signs and Symptoms

The symptoms of a deviated patella primarily revolve around pain and altered knee mechanics. Common indicators include:

• Anterior Knee Pain: Pain felt around or behind the kneecap, often described as a dull ache. This pain typically worsens with activities that load the patellofemoral joint, such as:
  • Climbing or descending stairs
  • Squatting or lunging
  • Running, especially downhill
  • Prolonged sitting with knees bent ("theater sign")
• Crepitus: A grinding, popping, or clicking sensation during knee movement, which may or may not be painful.
• Feeling of Instability or "Giving Way": A sensation that the knee might buckle or give out, especially when descending stairs or changing directions.
• Swelling: Mild swelling around the kneecap may occur, particularly after activity, due to inflammation.
• Tenderness: Pain upon palpation around the edges of the patella.
• Visual Observation: In some cases, a trained eye may observe the patella appearing to sit slightly off-center or shifting during knee motion.

Diagnosis

Diagnosing a deviated patella requires a thorough evaluation by a healthcare professional, such as an orthopedic surgeon, sports medicine physician, or physical therapist. The diagnostic process typically includes:

• Detailed History: Gathering information about the onset of pain, aggravating and relieving factors, and activity levels.
• Physical Examination:
  • Observation: Assessing patellar position at rest and during movement.
  • Palpation: Checking for tenderness around the patella.
  • Range of Motion: Evaluating knee flexion and extension.
  • Strength Testing: Assessing the strength of the quadriceps, hip abductors, hip external rotators, and core muscles.
  • Flexibility Assessment: Checking for tightness in the quadriceps, hamstrings, IT band, and hip flexors.
  • Special Tests: Performing specific maneuvers to assess patellar tracking and stability (e.g., patellar apprehension test, Q-angle measurement).
• Imaging Studies:
  • X-rays: To assess bony alignment, patellar height (patella alta), and the shape of the trochlear groove.
  • MRI (Magnetic Resonance Imaging): To visualize soft tissues (cartilage, tendons, ligaments) and assess for cartilage damage or other internal derangements.
  • CT Scan (Computed Tomography): Can provide detailed cross-sectional images for precise measurement of patellar tilt and rotation, especially useful in complex cases.
• Gait Analysis: Observing walking and running patterns to identify biomechanical abnormalities that contribute to the deviation.

Management and Treatment Strategies

Treatment for a deviated patella is overwhelmingly conservative and focuses on addressing the underlying causes of maltracking. Surgical intervention is typically reserved for severe, persistent cases that do not respond to extensive conservative management.

Conservative Management (Primary Approach)

The cornerstone of treatment for a deviated patella involves physical therapy and lifestyle modifications:

• Rest and Activity Modification: Temporarily reducing or avoiding activities that exacerbate pain allows inflammation to subside. Gradually reintroducing activities is crucial.
• Pain and Inflammation Control:
  • RICE Protocol: Rest, Ice, Compression, and Elevation can help manage acute pain and swelling.
  • NSAIDs: Over-the-counter non-steroidal anti-inflammatory drugs (e.g., ibuprofen, naproxen) may be recommended for short-term pain relief.
• Physical Therapy: A structured rehabilitation program is critical. This typically includes:
  • Strengthening Exercises:
    • Vastus Medialis Obliquus (VMO): Exercises like terminal knee extensions, inner range quadriceps exercises, and specific VMO activation drills.
    • Hip Abductors and External Rotators: Exercises targeting the gluteus medius and minimus (e.g., clam shells, side-lying leg lifts, band walks) to improve hip stability.
    • Core Strength: Strengthening the abdominal and back muscles to improve trunk stability.
  • Stretching Exercises: Addressing tightness in the quadriceps, hamstrings, IT band, and hip flexors.
  • Manual Therapy: Techniques such as patellar mobilization to improve mobility and reduce stiffness.
  • Neuromuscular Retraining: Improving proprioception (body awareness) and control during functional movements.
  • Gait and Movement Pattern Retraining: Correcting faulty mechanics during activities like squatting, lunging, and running.
• Patellar Taping or Bracing: Kinesiology tape or specialized patellar braces can help provide temporary support and guide the patella into better alignment during activity, reducing pain.
• Orthotics: Custom or over-the-counter shoe inserts can correct excessive foot pronation, which can influence knee alignment.
• Patient Education: Understanding the condition, identifying aggravating factors, and learning proper body mechanics are vital for long-term management.

Surgical Intervention (Less Common)

Surgery is considered only when conservative measures have failed to provide relief after an extended period (typically 6-12 months) and when significant anatomical abnormalities or recurrent instability are present. Surgical procedures aim to realign the patella and improve its tracking:

• Lateral Retinacular Release: Cutting the tight lateral retinaculum to reduce the outward pull on the patella.
• Medial Patellofemoral Ligament (MPFL) Reconstruction: Reconstructing the MPFL, a key ligament that stabilizes the patella medially, often performed for recurrent patellar dislocations.
• Tibial Tubercle Osteotomy: Repositioning the bony attachment of the patellar tendon (tibial tubercle) to alter the angle of pull on the patella.
• Trochleoplasty: Reshaping a shallow trochlear groove to provide better containment for the patella.

Prevention

While not all cases of patellar deviation are preventable, especially those due to significant anatomical factors, many can be mitigated or avoided by focusing on:

• Balanced Strength Training: Incorporating exercises that strengthen all aspects of the quadriceps, as well as the hip and core musculature.
• Flexibility: Regular stretching to maintain adequate flexibility in the quadriceps, hamstrings, IT band, and hip flexors.
• Proper Biomechanics: Learning and applying correct form during all exercises and functional movements, especially squats, lunges, and running.
• Gradual Progression: Slowly increasing the intensity, duration, or frequency of physical activities to allow the body to adapt.
• Appropriate Footwear: Wearing supportive shoes that fit well and are appropriate for the activity. Considering orthotics if foot overpronation is an issue.
• Listening to Your Body: Addressing minor aches and pains early before they develop into chronic conditions.

Conclusion

A deviated patella, or patellar maltracking, is a common condition characterized by the abnormal movement of the kneecap within its femoral groove. While it can cause significant anterior knee pain and functional limitations, it is highly manageable with a comprehensive, evidence-based approach. Understanding the intricate interplay of muscular imbalances, anatomical predispositions, and biomechanical factors is key to effective treatment. For individuals experiencing symptoms, consulting with a qualified healthcare professional is crucial for accurate diagnosis and the development of a tailored rehabilitation plan focused on restoring proper patellar tracking and alleviating pain.