What is Patellofemoral Instability?
Patellofemoral instability is a condition that impacts the knee, particularly how the kneecap (patella) glides over the thigh bone (femur). This instability happens when the patella shifts out of its usual trajectory during knee flexion and extension, often leading to dislocation or subluxation (partial dislocation). The condition can be triggered by an acute traumatic event or be a chronic issue due to anatomical anomalies or muscular imbalances.
Risk Factors for Patellofemoral Instability
Several factors can heighten the risk of developing patellofemoral instability. These include:
Anatomical Factors: Certain anatomical characteristics can predispose individuals to patellofemoral instability. These include a high-riding patella (patella alta), an abnormal shape of the patellar or trochlear groove, and excessive knee valgus (knock-knee).
Muscular Imbalances: Weakness or imbalance in the muscles surrounding the knee, especially the quadriceps, can lead to improper tracking of the patella.
Previous Dislocation: Individuals who have suffered a patellar dislocation are at higher risk of future episodes due to potential damage to the stabilising structures around the patella.
High-impact Sports: Engagement in high-impact sports that involve jumping, twisting, or sudden changes in direction can increase the risk of patellar instability incidents.
Hypermobility Syndromes: Conditions that result in increased joint laxity, such as Ehlers-Danlos syndrome, can contribute to the development of patellofemoral instability.
Symptoms of Patellofemoral Instability
The symptoms of patellofemoral instability can vary, depending on whether the condition is acute or chronic. Common symptoms include:
- Pain around the kneecap, particularly when bending the knee, climbing stairs, or after sitting for extended periods.
- A sensation of the knee "giving way" or instability.
- Swelling of the knee joint.
- Audible popping or clicking sounds during knee movement.
- Visible displacement of the kneecap, especially after a dislocation event.
Diagnosis of Patellofemoral Instability
Diagnosing patellofemoral instability involves a detailed medical history, physical examination, and imaging studies. During the physical examination, your Doctor or Orthopaedic Surgeon will assess for signs of patellar maltracking, muscle imbalances, and the knee's structural integrity. Imaging studies, such as X-rays and CT scans, can help identify any anatomical anomalies, while magnetic resonance imaging (MRI) is useful for evaluating the soft tissue structures around the patella, including the cartilage and ligaments.
Management of Patellofemoral Instability
The management of patellofemoral instability depends on the severity of the condition and whether it is an acute injury or a chronic issue.
Conservative Treatment: Initial treatment often involves conservative measures, such as rest, ice, compression, and elevation (RICE) to manage acute symptoms. Physiotherapy plays a crucial role in strengthening the quadriceps and other muscles around the knee to improve patellar tracking. Additionally, bracing or taping may be used to stabilise the patella during activities.
Medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) can be used to reduce pain and inflammation. Consideration of these being appropriate will be dependent on other medical comorbidities.
Surgical Treatment: Surgery may be considered for individuals who do not respond to conservative treatment or who experience recurrent dislocations. Surgical options aim to correct anatomical anomalies, repair or reconstruct ligaments, and realign the patellar tracking. The specific procedure is tailored to the patient's unique condition. Surgical options can include reconstructing ligaments such as the medial patellofemoral ligament (MPFL) or realigning the kneecap through various techniques depending on the patient's age, bone maturity, and specific anatomical issues.
Recovery and rehabilitation play critical roles in managing patellofemoral instability, emphasising the importance of following medical advice and engaging in recommended physical therapy to strengthen the knee and prevent future dislocations.
Patellofemoral instability is a multifactorial condition that requires a comprehensive approach for diagnosis and management. Recognising the risk factors and symptoms can aid in early detection and prevention of further knee damage. Through a combination of conservative treatment, physiotherapy, and possibly surgery, individuals with patellofemoral instability can achieve improved knee function and stability. It is vital for patients to collaborate closely with their medical team to develop a treatment plan that addresses their specific needs. I’m available to help and treat patients with patellofemoral instability. If you would like further advice and assistance in management, please contact my team and book an appointment to discuss this further.
