title: [Recurrent hematomas of the iliopsoas muscle after total hip replacement as a differential diagnosis for chronic groin pain: case series report].
abstract: BACKGROUND
  Chronic and atraumatic groin pain may be due to a variety of pathologies local to and distal from the hip joint. Aside from frequent entities, such as inguinal hernia, impingement of the iliopsoas muscle by the anterior rim of the acetabular component leading to a hematoma can be a potential cause after total hip replacement (THR).
  
  
  METHODS
  This article presents three cases of delayed groin pain after THR received due to osteoarthrosis of the hip joint several years prior to the onset of symptoms. In all three cases the patient suffered from chronic groin pain aggravated by active flexion without direct trauma. After thorough clinical, laboratory and radiological (ultrasound, x-ray, computed tomography) examination a hematoma of the iliopsoas muscle was detected. Furthermore, in all three cases the acetabular component appeared to be slightly malpositioned. Considering the least invasive procedure all cases were treated with an excavation of the hematoma. After recurrence the indications for revision of the malpositioned acetabular component were present.
  
  
  RESULTS
  All patients clearly showed a reduction of pain after operative revision. There have been no further hematomas and the patients could be easily and rapidly remobilized.
  
  
  CONCLUSIONS
  Persistent atraumatic groin pain connected to a deficit in hip flexion after THR needs thorough investigation by the treating physician. The differential diagnosis of a delayed hematoma due to impingement of the iliopsoas muscle is a rare but more complex entity. After careful consideration of the perioperative risks an early indication for revision of a malpositioned acetabular component is promising.
authors.affiliation: Klinik und Poliklinik für Unfallchirurgie, Klinikum Rechts der Isar, Technische Universität München. karl.braun@mri.tum.de
authors.forename: K F
authors.initials: KF
authors.lastname: Braun
authors.forename: S
authors.initials: S
authors.lastname: Siebenlist
authors.forename: G
authors.initials: G
authors.lastname: Sandmann
authors.forename: F
authors.initials: F
authors.lastname: Martetschläger
authors.forename: T
authors.initials: T
authors.lastname: Kraus
authors.forename: S
authors.initials: S
authors.lastname: Ehnert
authors.forename: M
authors.initials: M
authors.lastname: Neumaier
authors.forename: T
authors.initials: T
authors.lastname: Freude
authors.forename: U
authors.initials: U
authors.lastname: Stöckle
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018771:Arthralgia / Q000175:diagnosis* / Q000209:etiology*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D003937:Diagnosis, Differential; D005260:Female; D006119:Groin; D006406:Hematoma / Q000175:diagnosis* / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000175:diagnosis* / Q000209:etiology*