A dislocated knee occurs when the bones forming the knee joint move out of their normal alignment. This can involve the kneecap (patella) slipping out of its groove or, in more severe cases, the shinbone (tibia) separating from the thighbone (femur). This painful injury requires immediate medical attention. The joint disruption can damage surrounding ligaments, tendons, and potentially blood vessels or nerves.
Immediate Steps
If someone experiences a dislocated knee, urgent action is necessary before medical help arrives. The first step involves calling emergency services, such as 911 or your local equivalent, to ensure prompt transport. While waiting, keep the injured person calm and reassure them.
The injured leg should be stabilized immediately. Do not attempt to move, straighten, or force the knee back into place. Trying to “fix” the dislocation at home can cause further damage to the joint, ligaments, or surrounding tissues. Support the knee in the position it is found using pillows or rolled clothing to reduce movement.
Applying a cold pack or ice wrapped in a cloth to the injured area can help manage swelling and pain. Do not apply ice directly to the skin. Keeping the leg slightly elevated, if comfortable, can also reduce swelling.
Medical Treatment
Upon arrival at a medical facility, healthcare professionals will assess the injury through a physical examination. This includes checking for visible deformity, swelling, and pulses in the lower leg to identify any potential blood vessel or nerve damage. Prompt evaluation of neurovascular status is important due to the risk of complications.
Diagnostic imaging, such as X-rays, will be performed to confirm the dislocation and check for any associated fractures. An MRI scan may also be ordered to assess damage to ligaments, cartilage, and other soft tissues around the knee. In some cases, an arteriogram might be used to evaluate blood flow through the arteries.
The process of moving the knee back into its proper alignment is called reduction. This is typically done as a closed reduction, where a physician manually repositions the bones without surgical incisions. This procedure is usually performed under sedation or pain medication to ensure patient comfort. If closed reduction is unsuccessful or if there are complicating factors like trapped tissues, open reduction via surgery may be necessary.
Recovery and Long-Term Care
Once the knee has been reduced, post-reduction care focuses on stabilizing the joint and managing discomfort. The knee is typically immobilized using a brace or cast for several weeks to allow initial healing. Pain management often involves prescribed medications and continued application of ice to reduce swelling. Elevating the leg above the heart when resting can further help control swelling.
Physical therapy plays an important role in regaining full knee function. A tailored rehabilitation program will include exercises to restore range of motion, strengthen surrounding knee muscles, and improve stability. Adherence to the physical therapy regimen is important for recovery and to prevent stiffness.
The typical recovery timeline for a dislocated kneecap ranges from six to eight weeks for a return to normal daily activities. Full return to sports or higher impact activities might take three to four months. If surgery was required due to significant damage or recurring dislocations, the recovery period can extend to a year or longer, depending on the injury’s extent and repairs.
Preventing Recurrence
Minimizing the risk of future knee dislocations involves addressing contributing factors and implementing preventative measures. Causes can include direct trauma, excessive pressure from movement, or underlying anatomical predispositions like a shallow kneecap groove or ligamentous laxity. Individuals with weak leg muscles, wider hips (in women), or a history of previous dislocations may also be at higher risk.
Strengthening the muscles around the knee, particularly the quadriceps and hip muscles, helps provide stability to the joint. Engaging in physical therapy exercises regularly can help condition these muscles. Proper technique during sports and physical activities, especially those involving sudden changes in direction, can also reduce strain on the knee.
Wearing appropriate protective gear, such as knee support braces, may offer stability and protection against impacts. For individuals with chronic dislocations, surgical interventions might be considered to correct anatomical issues or reconstruct damaged ligaments, to reduce future episodes.