title: Greater trochanter pain syndrome: a descriptive MR imaging study.
abstract: OBJECTIVE
  Greater trochanter pain syndrome (GTPS) is a diverse clinical entity caused by a variety of underlying conditions. We sought to explore the impact of (1) hip morphology, namely the center-edge angle (CEa) and femoral neck-shaft (NSa) angle, (2) hip abductor tendon degeneration, (3) the dimensions of peritrochanteric edema and (4) bursitis, on the presence of GTPS, using MR imaging.
  
  
  METHODS
  The presence of pain was prospectively assessed blindly by the senior author. CEa and NSa were blindly measured in 174 hip MR examinations, after completion of the clinical evaluation by another evaluator. The existence and dimensions of T2 hyperintensity of the peritrochanteric soft tissues, the existence and dimensions of bursae, as well as degeneration and tearing of gluteus tendons were also recorded.
  
  
  RESULTS
  Out of 174 examinations, 91 displayed peritrochanteric edema (group A) and 34 bursitis, all with peritrochanteric edema (group B). A number of 78 patients from both A and B groups, showed gluteus medius tendon degeneration and one tendon tear. CEa of groups A and B were 6° higher than those of normals (group C, P=0.0038). The mean age of normals was 16.6 years less than in group A and 19.8 years less than in group B (P<0.0001). Bursitis was associated with pain with a negative predictive value of 97% (P=0.0003).
  
  
  CONCLUSIONS
  Acetabular morphology is associated with GTPS and the absence of bursitis was proved to be clinically relevant. Peritrochanteric edema alone was not associated with local pain.
authors.affiliation: Department of Medical Imaging, University Hospital of Heraklion and Radiology Section, Medical School University of Crete, Greece. Electronic address: miklontzas@gmail.com.
authors.forename: Michail E
authors.initials: ME
authors.lastname: Klontzas
authors.affiliation: Department of Medical Imaging, University Hospital of Heraklion and Radiology Section, Medical School University of Crete, Greece. Electronic address: akarantanas@gmail.com.
authors.forename: Apostolos H
authors.initials: AH
authors.lastname: Karantanas
mesh_terms: D000328:Adult; D018771:Arthralgia / Q000473:pathology*; D002062:Bursitis / Q000473:pathology; D004487:Edema / Q000473:pathology; D005260:Female; D006621:Hip Joint / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013577:Syndrome; D013708:Tendon Injuries / Q000473:pathology
keywords: Bursitis; CE angle; Gluteal tendinopathy; Greater trochanter pain syndrome; MR imaging