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Iliopsoas bursitis is inflammation of a bursa (synovial sac) lying between iliopsoas muscle and hip joint, lateral to femoral vessels. Pain is experienced over the same area and made worse by extension of hip joint.
References
Fauci, Anthony (2010). Harrison's Rheumatology, Second Edition. McGraw-Hill Professional Publishing; Digital Edition. p. 271. ISBN9780071741460.