The knee is the largest joint in the body and is considered the most complicated one. It enables hinge and rotator movements as it forms the connection between the upper and lower leg. Sometimes, the function of the knee can be affected by metabolic disorders. A metabolic disorder occurs when there is an alteration in the normal metabolic process due to abnormal chemical reactions. This leads to an imbalance in the body's metabolism as you will have too much or too little of essential substances.
The actual causes of metabolic disorders that affect the knee are unknown. However, we can still seek to understand the signs and symptoms of these disorders.
Gout
It is a form of acute arthritis which causes severe pain and swelling in the joints such as the knee, ankle, and heel. It is an inflammatory condition that is characterized by intense pain, swelling, and redness of the knee joint. Gout develops due to increased levels of uric acid in the blood or hyperuricemia.
Symptoms
- Pain
- Tenderness
- Redness
- Warmth and swelling of the knee joint
- Inflammation (skin appears red, shiny, and dry)
- Mild fever
Osteomalacia
Osteomalacia is the softening of the bones that occur due to inadequate levels of phosphate, calcium, and vitamin D or resorption of calcium. Osteomalacia is commonly caused by vitamin D deficiency. The other two causes are insufficient calcium absorption from the intestine and phosphate deficiency caused by increased renal losses.
Sign and symptoms
- Diffused joint and bone pain
- Muscle weakness
- Difficult to walk
- Hypocalcemia
- Pelvic flattening
- Bending of the bones
Chondrocalcinosis
Chondrocalcinosis is characterized by deposits of calcium pyrophosphate dihydrate crystals in one or more joint cartilages resulting in damage to the joints. It commonly affects the knee. It occurs in a hereditary form associated with metabolic disorders.
Sign and symptoms
- Swelling
- Stiffness
- Pain
Paget’s disease
Paget’s disease occurs due to excessive breakdown or formation of bone. This causes the bone to grow larger and weaker than normal, leading to the risk of fracture. The disease may affect more than one bone and occurs commonly in the knees, skull, and hip joints, etc.
Signs and symptoms
Many people don’t have symptoms. When symptoms occur, the most common symptom of Paget’s disease is pain. The other symptoms include:
- Bending of the bones
- Tingling and weakness
It may also cause osteoarthritis.
Osteoporosis
Abnormalities in the levels of calcium, vitamin D, and phosphorous can lead to osteoporosis of the bones. It causes bones to become weak and brittle. It occurs when the creation of new bone does not keep up with the removal of old bone.
Signs and symptoms
In the early stage of bone loss, there are no specific symptoms. You may notice the symptoms, once the bones have been weakened by osteoporosis. They include:
- Back pain
- Loss of weight over time
- Stooped posture
- Bone fracture
Osteoarthritis
It is a common form of arthritis affecting millions of people. It occurs when the cartilage on the ends of the bones wears and tears away. It can damage any point in the joint mainly the knee, hip, and spine joints. When there is an error in metabolism due to diseases like Paget’s disease, it may lead to osteoarthritis.
Signs and symptoms
- Pain
- Tenderness
- Stiffness
- Loss of flexibility
- Grafting sensation
- Bone spurs (extended growth of the bone)
Metabolic disorders of the knee can be reduced by taking a proper diet. You need to consume foods containing abundant amounts of calcium, proteins, and vitamin D. Some metabolic disorders can be rectified by treatment and some by lifestyle changes.
You can also promote your bone health by maintaining a healthy weight, exercising regularly, and restricting alcohol and tobacco use. Seek your doctor’s help if you notice any symptoms and get it treated in the early stages.
