From the Guidelines
Hip synovitis in a 21-year-old female is most likely caused by trauma, infection, or autoimmune conditions, and a thorough diagnostic approach is necessary to determine the specific cause and guide treatment. The causes of hip synovitis can be diverse, including:
- Trauma, which can result from direct injury, overuse during physical activities, or repetitive motions that strain the joint 1
- Infectious causes, such as bacterial infections (septic arthritis), viral infections, or Lyme disease
- Autoimmune conditions like rheumatoid arthritis, juvenile idiopathic arthritis, or systemic lupus erythematosus, which can trigger synovitis even in young adults 1
- Other potential causes, including transient synovitis (often following an upper respiratory infection), femoroacetabular impingement, or inflammatory bowel disease, which can have extra-intestinal manifestations affecting joints
- Less common causes, such as pigmented villonodular synovitis (a benign tumor-like condition) or crystal deposition diseases
According to the EULAR recommendations for the management of early arthritis, clinical examination is the method of choice for detecting synovitis, and in doubtful cases, ultrasound, power Doppler, and MRI might be helpful to detect synovitis 1. Additionally, exclusion of diseases other than rheumatoid arthritis requires careful history taking and clinical examination, and ought to include at least the following laboratory tests: complete blood cell count, urinary analysis, transaminases, antinuclear antibodies 1. Referral for specialist opinion is recommended for anyone with suspected persistent synovitis of undetermined cause, even if blood tests show a normal acute-phase response or negative rheumatoid factor 1.
From the Research
Causes of Hip Synovitis
The causes of hip synovitis in a 21-year-old female can be attributed to various factors, including:
- Infection: Septic arthritis is a possible cause of hip synovitis, which can be caused by bacteria, viruses, fungi, or mycobacterium 2, 3.
- Transient synovitis: Although rare in adults, transient synovitis is a benign, self-limiting condition that can cause hip pain and synovitis, and is largely believed to be viral in nature 4, 5.
- Synovial diseases: Pigmented villonodular synovitis (PVNS) and synovial chondromatosis (SC) are rare synovial diseases that can induce joint destruction and cause hip synovitis 6.
- Trauma: Traumatic injury to the hip joint can also cause synovitis.
- Autoimmune disorders: Certain autoimmune disorders, such as rheumatoid arthritis, can increase the risk of developing hip synovitis 3.
Risk Factors
Risk factors for hip synovitis include:
- Age: Although septic arthritis is more common in older adults, it can occur at any age 3.
- Recent joint surgery or hip or knee prosthesis: Increases the risk of septic arthritis 3.
- Immunocompromised state: Increases the risk of septic arthritis 3.
- Skin infection: Increases the risk of septic arthritis 3.