THE CONDITION
The MPFL is the ligament that attaches the kneecap to the inner part of the knee. It helps stabilise the kneecap as the knee moves.
It is most commonly injured during traumatic dislocation of the patella caused by twisting injuries to knee when it is straight. Patients that have ligamentous laxity or weak musculature are at an increased risk of MPFL injury as are those with underlying abnormalities within the knee such as a high riding patella meaning the kneecap is easily dislocated.
THE DIAGNOSIS
The history taking and examination that will take place during your consultation will help with diagnosis. Tenderness on the inside of the knee and patella apprehension will be apparent further confirming the diagnosis. Imaging such as X-rays and MRI scans would be used to assess the MPFL and identify which part is ruptured. They would also identify any other knee problems such as loose fragments as a result of the dislocation.
THE SYMPTOMS
Patients commonly report an episode, or multiple episodes, of their kneecap dislocating. Often these episodes would have required relocation by a healthcare professional. When the MPFL is ruptured, there is apprehension when the kneecap is moved to the outside of the knee. This patella apprehension causes the patient pain. If there has been a recent dislocation the knee may be swollen.
THE TREATMENT
Most first time dislocations (and the associated MPFL injuries) are treated conservatively with a period of immobilisation – usually 2-4 weeks – followed by physiotherapy to strengthen the muscles around the knee. If the MPFL is too damaged to heal itself then surgery would be required. If scans have shown loose fragments of bone or cartilage in the knee then an arthroscopy would be performed to remove them. Surgery would involve either repairing the MPFL or using grafts to reconstruct it. Grafts would be taken from other ligaments within the patient’s own body.
THE PROGNOSIS
Most people can return to sports within 3 months after surgery.
