The knee joint is the biggest weight bearing joint in the body. It is a hinge joint which joins the round, bony ends of the thigh bone and the shin bone and in the front part it is bounded by the knee cap. Various ligaments, muscles and tendons allow joint motions to take place; whereas the menisci and cartilage cushions the joint against forces that the knee has to bear.
The knee pain is the most common musculoskeletal complaint. Although, the number of knee problems has increased, there are a number of causes and treatment options available to treat it. One such cause of discomfort in the knee is internal derangement of knee.
What is Internal Derangement of Knee?
The internal derangement of knee means an internal damage to the knee caused due to trauma. This damage can be due to injury or due to an overuse of the knee. The knee is usually resistant to vertical forces but sudden twisting and horizontal forces can cause injury to it. This damage results in certain disorders of joint which includes torn meniscus, loose bodies in the knee and damaged ligaments. Internal derangement of knee does not include chronic disorders such as osteoarthritis of the knee, chondromalacia patellae, discoid meniscus and meniscal cysts. Internal derangement of knee is also called as knee instability.
The knee has four major types of ligaments. These are the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL) and the lateral collateral ligament (LCL). They can move to only certain extent. When moved beyond these limits, it leads to damage in the form of ligament tear. The internal derangement can happen in any of these areas.
What Causes Internal Derangement of Knee?
The following are some of the causes of internal derangement of knee:
- Strenuous physical activities involved during sports, work-related activities and accidents can cause internal derangement of knee.
- A sudden stop while running
- A direct injury on the knee joint can also cause internal derangement of knee
- Ligament injuries occur while playing rugby and football
- Anterior cruciate ligament injuries occur in a gymnast
- Landing heavily on the flexed knee joints
- Elderly people (>60 years) are more prone to internal derangement of knee than young people.
Injuries to ligaments and menisci most often occur in middle aged adults. Females are more prone to patellar and lateral meniscus problems. Children experience more damage to the bones than to the ligaments of the knee joint.
Symptoms of Internal Derangement of Knee
The internal derangement of knee is associated with the following symptoms:
- A snapping or tearing sensation at the time of the injury can be a symptom of internal derangement of knee.
- The development of marked swelling within two hours which indicates bleeding of the joint
- An immediate sensation of instability can be a symptom of internal derangement of knee.
Prognosis of Internal Derangement of Knee
The internal derangement could be of different severities. Hence, prognosis depends on the severity of the condition, which treatment was given, the age and health status of an individual. The complications exist in case of internal derangement of the knee when one does not take proper rest and does not avoid further problem to the knee.
Diagnosis of Internal Derangement of Knee
The doctor performs the physical examination of the knee and checks for the signs and symptoms of the internal derangement of knee. He also records medical history of the patient.
- The imaging technique like X-ray is used but gives limited knowledge. Hence, MRI-scan is performed to view the ligaments, menisci and tendons; while CT scan is used to view bone fractures.
- Ultrasound is used to distinguish cysts, aneurysm and blood clots.
- An invasive surgical procedure such as arthroscopy is used. In this case a tiny camera is inserted into the knee joint for viewing the problem.
Treatment of Internal Derangement of Knee
Treatment for internal derangement of knee depends on the nature and the severity of the injury, age and health status of the patient.
- Mild internal derangement of knee can be treated at home as follows –
- One should rest the injured knee as much as possible
- Apply ice pack to ease the pain and swelling associated with internal derangement of knee
- Compression bandages to control swelling associated with internal derangement of knee
- While resting, one should place the legs and joint elevated on a pillow to reduce swelling
- Use of special knee braces
- Medications such as non-steroidal anti-inflammatory drugs can be taken to reduce symptoms of pain and swelling associated with internal derangement of knee.
- Some people may benefit from physical therapy and mild less strenuous exercises.
- In case of severe internal derangement of knee, surgery might be required.
Prevention of Internal Derangement of Knee
Prevention of internal derangement of knee is difficult as one cannot predict when accidents will occur! However, these are some of the precautions to be taken to minimize the chances of serious damage:
- Leg muscles should be kept strong by daily exercising
- The leg muscles should be always warmed up before embarking on strenuous activity
- Leg muscles should be stretched to maintain their flexibility
- The twisting movements should be performed properly to avoid knee injuries.
The internal derangement of the knee is a joint pathology. It is the result of an internal damage to the joint due to injury or overuse of the knee joint. Internal derangement of knee is commonly observed in the case of sport athletes. The mild forms of knee injury can be treated with home care remedies while the severe form requires surgical intervention.