Systemic Lupus Erythematosus or SLE is an autoimmune disease in which the immune system attacks its own tissues, causing chronic inflammation and tissue damage in the affected organs across the body, including joints, skin, brain, lungs, kidneys and blood vessels. Although SLE can affect people of all ages, it typically strikes females at far greater rates than males, particularly in younger age groups. Among other medications, oral corticosteroids are main therapeutic agents predominantly used to control systemic inflammations. Nevertheless, these drugs pose some undesired effects including early hip osteoarthritis. 

Get to know SLE

Systemic Lupus Erythematosus or SLE is an autoimmune disease occurs when the body’s immune system attacks its own tissues and organs. Since the inflammation is systematic, SLE can affect different systems in the body, including joints, skin, kidneys, blood cells, brain, heart and lungs. Clinical manifestations widely vary among individuals which may come on suddenly or develop gradually. Most common signs and symptoms of SLE are fever, fatigue, butterfly-shaped rash, loss of appetite, headache and joint or muscle pain accompanied by stiffness and swelling. If the inflammation caused by SLE involves the musculoskeletal system, the most affected parts are wrist, finger, ankle, knee and hip. 

Depending signs and symptoms, the medications often used to control inflammation include non-steroidal anti-inflammatory drugs (NSAIDs), immunosuppressants and corticosteroids.  

Regardless of doses, long-term use corticosteroids can substantially increase the risk of avascular necrosis (or osteonecrosis) of the hip which is the death of bone tissue due to a lack or disruption of blood supply to the head of femur. Therefore, SLE does not seem to be the causative factor of hip osteonecrosis directly, instead, long-term use of steroid drugs as a main therapy of SLE can potentially induce hip osteonecrosis. Nevertheless, the risk of developing hip osteoarthritis hinges upon overall health status of each individual. 

Signs and symptoms of hip osteoarthritis

Hip osteonecrosis induced by SLE can be classified into 4 stages, based on severity levels and impacts on daily life:

• Stage 1: Mild hip pain, throbbing pain in the hip-groin region while moving hip joints. Walking ability is not usually limited due to hip pain.  
• Stage 2: Moderate and constant hip pain whenever move. Walking ability is not usually limited due to hip pain.  
• Stage 3:  Femoral head collapses due to avascular necrosis and causes walking difficulty with unequal leg length, poor gait and severe pain that interrupts sleep at night.
• Stage 4: The acetabulum, the socket of the hip joint where the head of the femur meets with the pelvis becomes damaged, leading to the hip arthritis with severe hip pain and inability to walk.

Treatments of hip osteonecrosis

Once hip osteonecrosis develops, it cannot be reversed. Treatments are aimed to reduce pain and improve mobility while preserving patient’s quality of life. Treatment options of hip osteonecrosis induced by SLE are primarily determined by symptoms severity. Treatments include: 

1. Non-surgical approach: During the early stages, pain relievers, e.g. non-steroidal anti-inflammatory drugs (NSAIDs) can help alleviate hip pain. In some cases, physiotherapy might be suggested in conjunction with oral analgesics.   
2. Surgical approach: Surgery is often considered in patients who develop hip deformity or experience severe hip pain that limits their daily lives and activities. Surgical techniques used to treat hip osteoarthritis are as follows: 

• • Core decompression: This is a surgical procedure that involves surgical drilling into the area of dead bone near the joint to reduce pressure, allowing for the extra space within the bone. Besides reducing hip pain, this procedure increases blood flow and stimulates the production of healthy bone tissue, resulting in slows or stops bone and joint destruction.
  • Hip replacement surgery using The direct anterior approach (DAA): If the hip bone has collapsed, the orthopedic surgeon might recommend hip surgery to replace the damaged parts of hip joint with prosthetic implant. Due to the advancements in orthopedic surgery, the direct anterior approach provides the direct access to the anterior aspect of the hip without detaching any muscles and tendons. Considered as a minimally invasive surgery, this approach involves a 3-to 4-inch incision on the front of the hip through the bikini line that allows the joint to be replaced by moving muscles aside along their natural tissue planes, while preserving surrounding tissues and tendons. Unlike traditional approaches, both hips can be simultaneously operated at the same time using DAA technique, ensuring equal leg length after surgery. Superior advantages over previous techniques include smaller incision leading to less pain, less blood loss and fewer postoperative complications.  Due to no muscle detachment, it results in faster recovery time and shorter hospital stay. On average, hospitalization after DAA hip replacement surgery requires only 1-2 days. These benefits enable patients to live more active lives with a better quality of life. 

Corticosteroids and hip osteoarthritis

Corticosteroids are a type of anti-inflammatory drug. They are typically prescribed to treat a wide range of conditions, such as SLE, sudden sensorineural hearing loss, asthma, neuromyelitis optica spectrum disorder, glomerulonephritis and other inflammatory diseases. The appropriate dosage regimens for each condition are determined by the specialists. Corticosteroids do not tend to cause significant side effects if they are only taken for a short time or at a low dose. However, they might induce hip osteonecrosis in which its occurrence appears to be irrelevant to administered dose and duration, but individual’s response and overall health status.