An unstable patella occurs when the kneecap is not as secure as it should be. As a result, the patella (kneecap) shifts out of place from the groove at the femur end, which secures it firmly in place. Usually, the patella moves regularly in an up and down motion within a notch, similar to a V-shape, also known as the trochlear groove. However, considering how unstable the patella may be, it may not shift into the groove as it should.
Instability of the patella is most often caused by a dislocation, which causes the kneecap to slip out of place, usually to the outside of the knee, and, as a result, the medial patellofemoral ligament (MPFL) tears. A knee dislocation may be partial (subluxation) or complete. A complete dislocation occurs when the ligaments that secure the kneecap firmly in position stretch. As a result, these ligaments move toward the outside of the knee, along with the patella. In contrast, a partial knee dislocation occurs when the kneecap does not move entirely out of position. While this kind of injury can be treated without surgery in many cases, some patients require a surgical treatment known as MPFL reconstruction. During the procedure, I will take the patient’s hamstring tendon to reconstruct the ligament. The graft is then placed in the anatomical position for stability through a full range of motion.
MPFL reconstruction is a surgical procedure that develops a newly-formed medial patellofemoral ligament to secure the knee and safeguard the site from additional damage.
Typically, the kneecap is likely to dislocate during contact sports while pivoting or tackling. The ligament around the kneecap will tear, and surgery is the only means of correcting this. The MPFL is similar to a strong, flexible rubber band, stabilising and strengthening the knee joint. Additionally, the MPFL, the ligament travelling from the femur to the patella's centre, prevents dislocation. Reconstruction of the ligament using a graft is ideal for recreating the MPFL to ensure knee stability.
Most candidates eligible for MPFL reconstruction are those who sustain repeat knee dislocations. Usually, the medial patellofemoral ligament is prone to injury, particularly during intense, high impact sports.
No, MPFL reconstructive surgery is considered an outpatient procedure, so you can ask someone to drive you home after surgery, generally two hours after the procedure. The recovery after MPFL reconstruction does take weeks to months.
An untreated MPFL can heal on its own. However, when the ligament is left to heal, it does so unusually, losing its laxity.