Smooth knee movement can be affected by this condition. Please find out more about what it means and how to treat it.
Knee movement is typically smooth, with the kneecap (patella) gliding within a V-shaped groove at the end of the thigh bone, called the trochlea. This stable movement allows you to stand, walk, and run without issues as the patella moves up and down as you bend and straighten your knee.
However, for some individuals, this smooth movement is disrupted. Think of the patella as a train and the trochlear groove as the track. For patients with patellar dislocation, the train (patella) comes off the track, leading to knee instability, pain, and swelling.
Complete vs. Partial Dislocation
In a complete dislocation, the kneecap moves entirely out of the groove. Some people may experience partial dislocation, or subluxation, where the kneecap moves but does not fully dislocate. This can cause pain, swelling, stiffness, and sensations of popping or cracking, though the recovery time is generally shorter than that of a complete dislocation.
Regardless of whether the dislocation is partial or complete, injury to the surrounding ligaments and cartilage often occurs. When the medial patellofemoral ligament (MFPL), which stabilizes the kneecap, is damaged, the risk of repeated dislocation increases.
Recognizing a Dislocated Patella
With a partial dislocation, symptoms may be subtle, such as pain around the kneecap or a sensation of it popping in and out. A complete dislocation is usually more noticeable, with the knee buckling and an inability to bear weight. Swelling, pain, and stiffness are common, and even if the kneecap returns to its proper place on its own, lingering pain and swelling can persist.
Who Is at Risk?
Patellar dislocations can affect anyone, but they are most common in young women, especially in their teens or early twenties. Risk factors include abnormal trochlear shape, looseness in soft tissues, or a high-riding kneecap, conditions that may only be identified by a doctor.
Diagnosis of a Dislocated Patella
Doctors begin diagnosing patellar instability by listening to how the injury occurred and conducting a physical exam. This exam includes observing the knee’s movement and applying slight pressure on the kneecap, which can be uncomfortable for those with instability. X-rays and MRIs are commonly used to assess bone alignment and check for damage to ligaments and cartilage.
Can Patellar Dislocation Happen Again?
Adults over 25 who experience their first patellar dislocation typically have a low risk of recurrence with proper treatment, including bracing, crutches, and physical therapy. Younger patients, particularly those with a shallow trochlea, are more likely to experience repeated dislocations, potentially requiring surgery.
Treatment Options
If the kneecap does not realign itself after dislocation, a doctor will manually reduce the dislocation by applying gentle pressure. Rest, bracing, and crutches help the knee recover, while physical therapy strengthens the surrounding muscles to prevent future dislocations.
If imaging shows damage to the bone or cartilage, or if dislocations continue, surgery may be necessary. Arthroscopic surgery can repair the damage; in cases of repeated dislocation, reconstructive surgery to repair the torn ligament may be needed. Sometimes, a tibial tubercle osteotomy, a procedure to realign the bone, is performed alongside ligament surgery. Surgical success rates are high, with most patients avoiding further dislocations and returning to previous activity levels.
Precision Pain Care and Rehabilitation has two convenient locations in Richmond Hill – Queens, and New Hyde Park – Long Island. Call the Queens office at (718) 215-1888 or (516) 419-4480 for the Long Island office to arrange an appointment with our Interventional Pain Management Specialists, Dr. Jeffrey Chacko or Dr. Sonny Ahluwalia.
