Do you know about adult hip synovitis? When it comes to hip synovitis, most people think of pediatric temporary hip synovitis and pediatric transient hip synovitis, but few people think that adults can also suffer from hip synovitis. Until now, according to my personal review of the literature, there has not been a single monograph or journal that singles out adult hip synovitis as a disease name. Why is synovitis of the adult hip presented as a separate disease? A: Synovitis of the adult hip differs from synovitis of the child hip to varying degrees in its causes, predisposing factors, pathological mechanisms, diagnostic points and treatment methods. Hip joint pain, swelling, limping, pain in the ipsilateral inner thigh and knee joint, low fever and other discomfort are usually seen unilaterally or bilaterally, and the examination shows that the hip joint is in flexion, internal retraction and internal rotation with muscle spasm, pelvic tilt, unequal length of both lower limbs, positive “4” sign, occasionally positive Thomas sign, positive straight leg raise test. X-rays show obvious swelling of the hip capsule, widening of the joint space, but no bone destruction; MRI shows intracapsular synovial hypertrophy, roughness or entrapment, usually bilateral or unilateral, with pain in the groin, no obvious swelling, claudication or mild swelling, mild claudication, with mild restriction of limb movement, no hip flexion, inversion, internal rotation deformity and myospasm, no bilateral lower limb inequality and other signs The “4” sign was positive, the straight leg raise test was negative, and the Thomas sign was negative. The pelvic radiograph showed mild acetabular dysplasia without bone destruction; the MRI examination showed an increase in fluid in the hip joint cavity alone. Puncture examination The hip joint puncture examination is clear and negative for bacterial culture. Differentiation points All need to be differentiated from hip synovial tuberculosis, septic hip arthritis, ischemic necrosis of the femoral head, rheumatoid hip arthritis, hip osteoarthritis, sacroiliac arthritis, ankylosing spondylitis, and hip joint pigmented villous nodular synovitis.