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. The balance and optimal patellar gliding are maintained by several structures, divided into active (muscles) and passive (e.g.: ligaments, joint morphology, etc.) stabilisers. Patellar instability is an umbrella term that includes a spectrum of conditions from an occasional subluxation to a more severe dislocation. Patellar dislocations typically happen as a consequence of direct trauma to the knee or a non-contact twisting motion of the joint, however, some individuals can be more prone to these types of injuries due to some anatomical and physiological predisposing factors such as generalized ligament laxity or a shallow femoral trochlea (lateral “barrier” that contains the patella during knee motion). Kneecap dislocations tend to happen towards the lateral direction, mainly because of the knee structure and mechanics. During the dislocation event, the patient often reports hearing and feeling a “pop” which usually is due to the dislocation event itself and the rupture of the medial patellofemoral ligament (MPFL). After the dislocation, patients typically present with temporary deformity, pain, swelling, inflammation and decreased knee functioning.

Management

After a primary dislocation, the risk of relapse significantly increases, and rehabilitation plays a vital role in the management of these injuries. In most cases, these injuries can be managed conservatively by addressing the modifiable factors that can decrease the likelihood of this event reoccurring. Ensuring an optimal range of motion of the knee joint, muscle strength, balance between active and passive stabilisers and optimal movement quality will decrease the overall load directed to the knee joint and the lateral forces acting on the kneecap, reducing therefore the potential risk of relapse. In Isokinetic, our medical team will tailor a specific rehabilitation programme based on your needs to achieve your goals and minimise the risk of re-injury.

Surgical management

Some individuals with important structural damages to the passive stabilisers, anatomical and physiological aspects that predispose them to dislocation, or associated injuries that need to be addressed (e.g.: fractures, cartilage damage, etc.), may be potential candidates for surgical approach. In cases where rehabilitation alone is considered insufficient and a surgical procedure is deemed necessary, our excellent relationships with Orthopaedic Surgeons will allow us to promptly refer you to them for a surgical opinion. The main goal of the surgical procedure is to restore the static and dynamic alignment and balance of the kneecap during motion. Different procedures (such as MPFL repair or reconstruction, lateral release, distal realignment, trochleoplasty, etc.) could be implemented during surgery and are always discussed in detail with the patients and the medical-surgical team. It is important to stress that, despite restoring the optimal tracking and stabilisers of the kneecap through surgery, an extended period of rehabilitation is strongly recommended to ensure optimal long-term outcomes and prevent any relapse and symptoms. Specific post-surgical indications will be provided by the surgical team regarding immobilisation, use of crutches, bracing, etc., and our medical team will always work with the surgeon to optimise your outcomes.

Patella instability and dislocations