Patella instability (dislocation):
The joint between the kneecap (patella) and the thigh bone (trochlea) can be injured during sports and exercise resulting in dislocation of the patella or damage to the joint surface.
Dislocation of the patella can also occur with minimal trauma in certain individuals. The reason for this can be a small or high patella, abnormal alignment of the tendons of the patella or a shallow groove (trochlea) in the thigh bone. Often it is a combination of these acting together. The initial treatment of patella instability is physiotherapy to target the inside muscles of the leg including the quadriceps (Vastus medialis) gluteal muscles and hamstrings, this is often the only treatment necessary. If physiotherapy does not help the problem then surgery may be indicated. Individuals who suffer from patella dislocations are often predisposed to this by some anatomical variations. Depending on the cause of the dislocations you may require a reconstruction of the ligament on the inside of the patella, an operation to realign the patella tendon or an operation to deepen the groove in the trochlea. Often a combination of these operations is needed.
Tibial tubercle transfer for instability
Bearing surface damage on the patella
Damage or wear to the bearing surface of the patellofemoral joint can cause pain at the front of the knee along with a sensation of grinding/crunching/grating at the front of the knee. The pain is usually worse going down hills and stairs. This can often be treated without surgery. The factors that increase the load on the kneecap joint are poor muscle strength in the quadriceps (thigh) muscles and being overweight or obese. Targeted physiotherapy, exercise and weigh loss (where appropriate) can normally settle the pain from the patellofemoral joint without surgery.
If a 12 week course of physiotherapy does not settle the pain then arthroscopic surgery may be indicated.
The pain is the main thing we aim to cure and patients will often still feel some grinding even after surgery.