What is patella (knee cap) pain and subluxation?
The patella (kneecap) is a special bone positioned in the quadriceps tendon coming from the thigh. As the quadriceps muscle contracts, it pulls on the kneecap and the patellar tendon to extend or straighten the leg. Ligaments that surround the patella can be too tight or too loose. This causes the patella to be pulled to one side and results in misalignment and pain/swelling with repetitive movements. Patellar subluxation is the temporary dislocation of the kneecap from the femoral groove at the end of the femur.
How does knee cap pain and subluxation occur?
Repetitive movements of the knee can cause the tracking of the kneecap to be off. Factors such as a wider pelvis, a shallow groove for the knee cap, abnormalities in gait, and a misaligned patella put you at risk for a patellar subluxation. Traumatic events to the knee and hard twisting movements of the affected leg may be reported before you start dealing with this condition.
What are the symptoms of knee cap pain and subluxation?
Pain is usually well localized around the outer edge and front of the kneecap. You may see the kneecap pop in and out of the proper positioning as you bend and straighten your knee. The patella will usually subluxate to the lateral side. You may also experience stiffness in the affected leg and feel the knee catching.
How is knee cap pain and subluxation diagnosed?
A detailed history and physical will be performed. X-rays will be useful in determining the alignment of your kneecap at different points in your knee’s movement. An MRI may be ordered to evaluate the condition of soft tissues of the ligaments and tendons stabilizing the patella and the condition of the articular cartilage on the posterior surface of the patella.
How is knee cap pain and subluxation treated?
First, we must make sure your patella is not dislocated. If it is, reduction is the process in which we place your patella back into alignment. This prevents as much long-term damage to the bone and articular cartilage as we can at this time. Conservative therapy such as physical therapy, bracing, and better footwear will be attempted first. The goal is to strengthen your quadriceps and hip muscles and stabilize the patella to allow for proper patella alignment.
If conservative therapy fails, surgery by minimally invasive arthroscopic surgery is the best option to perform a lateral release. Small instruments are introduced around your knee to cut the lateral ligaments so that the pulling of your kneecap does not occur. Sometimes patients need an open procedure where the tissue is imbricated, or pulled back over with sutures, to realign the mal-tracking kneecap. Alternatively, the tibial tubercle osteotomy that involves taking the small bony portion of the tibia that the patella tendon connects to and moving it to a more medial and anterior position with sutures and anchors to allow for proper patella alignment.
What is the recovery time to knee cap pain and subluxation treatment?
Recovery time depends on the extent to which the patella has been damaged as a result of the subluxations and the individual patient’s healing process. Over several weeks, conservative therapy should help strengthen and stretch your muscles and ligaments so pain and swelling occurs less frequently. You should be able to start range of motion (ROM) exercises immediately after arthroscopy and be feeling much better after 2-3 months. Tibial tubercle osteotomies require longer recovery times because of the extent of the procedure, and you will be looking at 4-6 months until full activity is resumed.
Most of our patients are able to recover with our custom-tailored home exercise program which you will do on your own three times a day. You will be evaluated at your 2-week post-op appointment and outpatient physical therapy may be recommended at that time as an option to help speed the recovery process.
This is a unique condition which can be debilitating. Most common in young girls, it does require attention to rehabilitation activity levels. Surgery is a very effective end solution if conservative efforts fail.
We are here to help. If you believe you are suffering from knee cap pain and subluxation, we would love to deliver a diagnosis, get you treated and get you moving again.