The knee has three compartments, the patellofemoral compartment, which is located at the front of the knee, the medial compartment, which is on the inside portion of the knee, and the lateral compartment, which is on the outside portion.
What causes the patellofemoral instability is the misalignment of the kneecap from its normal pattern. This can damage structures such as the muscles and the ligaments that literally keep the knee together and in place.
Causes of Patellofemoral Instability
Patellofemoral instability is a result of variations in the shape of the patella, which moves up and down within the trochlear groove when you bend or straighten the knee. Patellofemoral instability is when the patella moves partially or completely outside of the trochlear groove.
Here’s a list of factors that can cause this:
- Anatomical defects such as flat feet, fallen arches, or congenital abnormalities in the patella bone.
- When the angle between the hips and knees, known as Q angle, is abnormally high, it can damage the patella.
- Damage or stretching of the soft tissue that supports the patella or femur
- Patellofemoral arthritis can also lead to patellofemoral instability because this causes articular cartilage loss on the back of the kneecap.
- Improper muscle balance is also a common cause. Weak quadriceps can lead to the subluxation, or dislocation, of the patella.
Patellofemoral Instability Symptoms
Patellofemoral instability causes pain when you stand up and the feeling that your knee can buckle or give way. It can also cause severe swelling and bruising, visible deformity, and loss of knee function. Patients can also experience numbness or partial paralysis, causes by the pressure put upon nerves and blood vessels.
Patellofemoral Instability Diagnosis
Proper and thorough diagnostic efforts are absolutely necessary in the field of orthopedic medicine. Not only are injuries significant, but treatments can be complex and will require a clear and absolute understanding of the severity and location of the patient’s condition.
Doctors can diagnose your patellofemoral instability by taking a look at your medical history and performing a physical examination. They can also use Xrays, MRI scans, and CT scans to determine your condition.
If the kneecap dislocation is only partial, non-surgical treatments might be enough to solve the issue. Among such treatments, we have the use of pain medications, rest, physical therapy, ice, orthotics, and knee-bracing.
If the dislocation is complete, it can be repositioned with a process called closed reduction.
Surgery is necessary when non-surgical methods fail to realign the kneecap and decrease the Q angle. Among the surgical options we have patellar realignment, proximal realignment, and distal realignment.
If the dislocation is truly severe, it’s necessary to perform a tibial tubercle transfer, where a section of bone is removed, shifted, then realigned with the patella, and reattached to the tibia with screws.
Possible risks and complications include loss of ability to extend the knee fully, recurrent dislocations or subluxations, arthrofibrosis, and persistent pain.
By working with a confident and proven team of orthopedic surgeons, you limit your risks that can result from surgery. With a thorough diagnostic process and history of success performing complex surgeries, patients should rarely experience adverse effects from surgery, especially effects that outweigh the benefits provided by the operation.
Other Spine List
- Normal Anatomy of the Knee Joint
- Knee Arthritis
- Knee Fracture
- Anterior Cruciate Ligament (ACL) Tears
- Meniscus Tear
- Arthroscopy of the Knee Joint
- Total Knee Replacement (TKR)
- ACL Reconstruction Hamstring Tendon
- ACL Reconstruction Patellar Tendon
- Uni Condylar Knee Replacement
- Meniscus Repair
- Anterior Cruciate Ligament ACL Reconstruction