Patellofemoral instability (dislocating kneecap)
Patellofemoral instability refers to a condition in which the patella (kneecap) does not properly track or move within the femoral groove (thigh bone) during knee flexion and extension. This can result in a range of symptoms, including pain, swelling, stiffness, and a sensation of the knee "giving way" or feeling unstable.
There are several potential causes of patellofemoral instability, including:
Anatomy: Certain anatomical factors, such as a shallow femoral groove or a high-riding patella, can increase the risk of patellar instability.
Trauma: A traumatic injury to the knee, such as a dislocated patella or a medial patellofemoral ligament tear, can lead to patellar instability.
Hyperlaxity or hypermobility (elastic collagen).
Muscle imbalances: Weakness or imbalance in the muscles surrounding the knee can affect the patella's alignment and stability.
Overuse: Repeated stress on the knee joint with hyperlaxity, such as from running or jumping, can lead to patellar instability over time.
Treatment for patellofemoral instability depends on the underlying cause and the severity of symptoms. Options may include physiotherapy to strengthen the muscles around the knee, bracing or taping to stabilize the patella, and in some cases, surgery to correct anatomical abnormalities or repair damaged ligaments
Medial Patellofemoral/MPFL reconstruction
Medial patellofemoral ligament (MPFL) reconstruction is a surgical procedure used to treat recurrent patellar instability, a condition where the kneecap (patella) dislocates or subluxates frequently. The MPFL is a ligament that helps to stabilize the kneecap as it moves along the femur bone in the thigh. When the MPFL is damaged or torn, the kneecap can become unstable and move out of its normal position.
kneecap instability (the “inverse J” sign)
During the MPFL reconstruction procedure, the damaged or torn ligament is replaced with a new one made from a tendon or ligament from another part of the body, or from a donor.
Small incisions are made around the knee and the kneecap is anchored (either with implants or with a tunnel through its substance) to the thigh bone to prevent dislocation, rather like the reigns of a horse holding it back from bolting. This stabilizes the kneecap and prevents it from dislocating or subluxing.
Recovery from MPFL reconstruction surgery usually takes several months, and patients will need to undergo physiotherapy to regain strength and mobility in the knee. They may also need to wear a brace or use crutches for 4-6 weeks after the surgery to protect the knee and allow it to heal properly.
Like any surgery, MPFL reconstruction carries risks, including infection, bleeding, nerve or vessel damage, a 2-5% risk of recurrent instability (higher in hyperlaxity) and complications from anaesthesia. However, the procedure is generally considered safe and effective for treating recurrent patellar instability.
Return to work depends on the patient's occupation; people with sedentary or office based work could return to work after one week but may need to adjust their seating positions, and may be distracted by postop pain medications.
People who work in heavy manual professions may require through 2-3 months off work depending on pain stiffness and strength of muscles.
Kneecap moving in straight line after MPFL reconstruction
Tibial tubercle transfer (bony relignment)
Tibial tubercle transfer is a surgical procedure that involves moving the bony prominence located on the front of the tibia (the tibial tubercle) to a new location on the bone. This procedure is typically performed in individuals who have a condition called patellar malalignment with a “raised tibial tubercle-trochlear groove distance TTTG”, or a high kneecap, which causes the kneecap to move out of place.
During the procedure, the surgeon makes an incision in the skin over the tibial tubercle and carefully detaches it from the underlying bone. The tubercle is then moved to a new location on the tibia and secured in place using screws or other fixation devices. This new position is intended to realign the patella and improve its stability within the knee joint.
Rehabilitation following tibial tubercle transfer typically involves a period of restricted movement in a brace for 4-6 weeks, followed by physiotherapy to help restore strength and range of motion in the knee.
Patients may need to wear a brace or use crutches for several weeks after the surgery to protect the healing bone and promote proper alignment of the patella.
Return to work depends on the patient's occupation; people with sedentary or office based work could return to work after one week but may need to adjust their seating positions, and may be distracted by postop pain medications.
People who work in heavy manual professions may require through 2-3 months off work depending on pain stiffness and strength of muscles.
As with any surgical procedure, there are risks associated with tibial tubercle transfer, including infection, bleeding, and nerve damage. Patients should discuss the potential benefits and risks of the procedure with their surgeon to determine if it is the right choice for them
Trocheloplasty of the high bone/femur
Trochleoplasty is a surgical procedure used to treat recurrent patellar dislocation, a condition in which the kneecap (patella) slips out of its normal position. The procedure involves reshaping the groove at the end of the thigh bone (femur) where the patella sits, known as the trochlea.
During trochleoplasty, the surgeon makes an incision in the knee to access the trochlea. They may use a variety of techniques to reshape the groove, such as removing bone, deepening the groove, or creating a new groove. The goal is to create a more stable and secure channel for the patella to move within, reducing the risk of dislocation.
Trochleoplasty is typically considered a complex and technically demanding surgery and is not recommended for all patients with recurrent patellar dislocation. The procedure carries risks, including infection, bleeding, nerve damage, and a potential decrease in range of motion or strength in the knee. Recovery time can vary but generally involves several weeks of rest and rehabilitation exercises to regain strength and mobility in the knee.