Management of Unstable Patella
Patellar Instability
This is one of my favourite subjects because of the sheer complexity and variability in its causes and management. Many times the problem is multifactorial and requires a detailed clinical and radiological assessment. I have a special interest in managing patellar instability and have performed multiple surgeries for unstable patella, including publishing articles on this topic.
Special Interest Area
Recurrent patellar instability is often complex, and treatment must be tailored carefully after understanding the exact anatomical and biomechanical cause.
Advanced Surgical Expertise
Complex surgeries such as trochleoplasty, derotation osteotomy, tibial tubercle transfer, and MPFL reconstruction may be required either alone or in combination.
Detailed Evaluation
Thorough clinical examination and imaging are essential because multiple factors often contribute to recurrent kneecap dislocation or maltracking.
Individualised Management
Treatment may range from physiotherapy and bracing to complex reconstructive procedures depending on the nature and severity of the problem.
Causes
The kneecap connects the muscles in the front of the thigh to the shinbone. As you bend or straighten your leg, the kneecap moves up and down. The thighbone has a V-shaped groove on the front, called the femoral groove, which accommodates this movement. In a normal knee, the kneecap fits and tracks smoothly within this groove.
If the groove is uneven or too shallow, the kneecap may slide out of place, resulting in a partial or complete dislocation. A sudden direct blow to the kneecap, such as during a fall, can also force the kneecap out of position.
Patellar instability is often not caused by a single issue. It may result from a combination of bony shape, soft tissue weakness, malalignment, and abnormal pull on the kneecap.
Symptoms
- Knee buckles and cannot support body weight properly
- Kneecap slips off to the side
- Knee catches during movement
- Pain in the front of the knee that increases with activity
- Pain while sitting for long periods
- Stiffness in the knee joint
- Creaking or cracking sounds during movement
- Swelling around the knee
Non-Surgical Treatment
- Reduction if the kneecap is completely dislocated
- Exercises to strengthen thigh muscles and improve alignment
- Cycling as part of physical therapy
- Use of a stabilising brace when required
- Gradual return to normal activities within 1 to 3 months in suitable cases
Treatment Approach
If the kneecap has completely dislocated out of its groove, the first step is to return it to its proper place. This is called reduction. Sometimes this happens spontaneously, while in other cases gentle assistance is needed to reposition the kneecap.
A dislocation can often damage the underside of the kneecap and the end of the thighbone, which may lead to additional pain and arthritis. Arthroscopic surgery can help address these associated injuries.
If the kneecap is only partially dislocated, nonsurgical treatment may be recommended initially. Exercises help strengthen the muscles in the thigh so the kneecap stays aligned better. A stabilising brace may also be prescribed, with the aim of returning the patient to normal activities within 1 to 3 months.
Surgical Treatment
Surgical planning is extremely important because recurrent patellar instability is often caused by multiple contributing factors. Depending on the anatomy and severity of the problem, one or more procedures may be required.
MPFL Reconstruction
The medial patellofemoral ligament, which helps hold the kneecap in position, is reconstructed using one of the extra tendons from the inner thigh through an arthroscopy-assisted minimally invasive procedure.
Trochleoplasty
This groove-deepening procedure is used when the femoral groove is too shallow. Bone is reshaped carefully to deepen the native groove while preserving the cartilage, allowing the kneecap to track more normally.
Derotation DFO
If rotational malalignment is contributing to the instability, this complex osteotomy helps correct the anatomy and improve patellar stability.
Tibial Tubercle Transfer
If the attachment of the patellar tendon on the shin bone is causing excessive outward pull on the kneecap, the tibial tubercle can be shifted medially to improve alignment.
These surgeries may be required in isolation or in combination, depending on the exact cause, severity, and structural abnormalities involved in the instability.