Patella instability and dislocations

The patellofemoral joint (PFJ) is a joint composed of the patella, often referred to as the kneecap, and the distal part of the femur which is constituted by the trochlea, a sulcus or groove where the patella makes contact and slides during motion. Optimal balance and sliding of the patella are maintained by several structures, divided into active (muscles) and passive (e.g., ligaments, joint morphology, etc.) stabilizers. Patellar instability is a generic term that includes a spectrum of conditions ranging from occasional subluxation to more severe dislocation. Patellar dislocation typically occurs as a result of direct trauma to the knee or a non-contact twisting motion, however, some individuals may be more prone to this type of condition due to certain predisposing factors (anatomical and physiological) such as ligamentous laxity or a shallow femoral trochlea ( a lateral “barrier” that contains the patella during knee motion). Patella dislocations tend to occur in the lateral direction, mainly due to the structure and mechanics of the knee. During the dislocation event, the patient often reports hearing and feeling a “pop” that is usually due to the dislocation event itself and the rupture of the medial patellofemoral ligament. After dislocation, patients usually present with temporary deformity, pain, swelling, inflammation, and reduced knee function.

Management

After a primary dislocation, the risk of recurrence increases significantly, and rehabilitation after patellar dislocation plays a key role in the management of these injuries. In most cases, these injuries can be managed conservatively by acting on modifiable factors that can reduce the likelihood of this event recurring. Ensuring optimal knee joint mobility, recovering muscle strength, restoring balance between active and passive stabilizers, and optimizing the patient’s quality of motion will decrease the overall load directed at the knee joint and the lateral forces acting on the patella, thereby reducing the potential risk of recurrence. At Isokinetic, our medical team will create a personalized rehabilitation program based on your condition to achieve your goals and minimize the risk of recurrence.

Surgical management

Some individuals with significant structural damage to passive stabilizers, anatomical and physiological aspects that predispose them to dislocation, or associated injuries that need to be stabilized (e.g., fractures, cartilage damage, etc.), may be potential candidates for a surgical approach. In cases where rehabilitation alone is considered insufficient and a surgical procedure is deemed necessary, our excellent relationships with orthopedic surgeons will enable us to refer you promptly to them for surgical advice. The main goal of the surgical procedure is to restore static and dynamic alignment and balance of the patella during movement. Several procedures (such as medial patellofemoral ligament repair or reconstruction, lateral release, distal realignment, trochleoplasty, etc.) could be implemented during surgery and are always discussed in detail with patients and the medical-surgical team. Importantly, despite the restoration of optimal sliding of the patella and patella stabilizers by surgery, a prolonged period of rehabilitation is strongly recommended to ensure optimal long-term results and prevent any re-injury and symptom episodes. The surgical team will provide specific post-operative guidance regarding immobilization, use of crutches, braces, etc., and our medical team will always work with the surgeon to optimize results.