Please cite this article in press as: Klontzas ME, Karantanas AH. Greater trochanter pain syndrome: A descriptive MR imaging study. Eur J Radiol (2014), http://dx.doi.org/10.1016/j.ejrad.2014.06.009 ARTICLE IN PRESS G Model EURR-6820; No. of Pages 6 European Journal of Radiology xxx (2014) xxx–xxx Contents lists available at ScienceDirect European Journal of Radiology j ourna l h om epage: www.elsevier.com/locate/ejrad Greater trochanter pain syndrome: A descriptive MR imaging study Michail E. Klontzas 1 , Apostolos H. Karantanas ∗ Department of Medical Imaging, University Hospital of Heraklion and Radiology Section, Medical School University of Crete, Greece a r t i c l e i n f o Article history: Received 15 January 2014 Received in revised form 8 April 2014 Accepted 16 June 2014 Keywords: Greater trochanter pain syndrome MR imaging CE angle Gluteal tendinopathy Bursitis a b s t r a c t 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. Materials and 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). Conclusion: 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. © 2014 Published by Elsevier Ireland Ltd. 1. Introduction Greater trochanter pain syndrome (GTPS) is characterized by pain and tenderness over the great trochanter. Its diagnosis is based on a combination of data from medical history, physical examina- tion and imaging findings. Female gender in the sixth decade, a femoral neck-shaft angle (NSa) less than 134 ◦ , and leg length dis- crepancies, have been described as risk factors for GTPS [1–3]. A variety of conditions, such as degenerative hip disease, femoroac- etabular impingement, femoral head avascular necrosis, infection and conditions that can modify hip biomechanics, such as knee osteoarthritis, iliotibial band syndrome and lumbar spine degen- erative disease, can clinically mimic GTPS, making the clinical differential diagnosis extremely complicated [4,5]. ∗ Corresponding author at: University of Crete, Department of Medical Imaging, University Hospital, Voutes 71110, Heraklion-Crete, Greece. Tel.: +30 2813392541; fax: +30 2813542095. E-mail addresses: miklontzas@gmail.com (M.E. Klontzas), akarantanas@gmail.com, karantanas@med.uoc.gr (A.H. Karantanas). 1 Address: Souliou 15 Poros, Heraklion, 71307 Crete, Greece. Tel.: +30 6977795314. Unlike the original belief that the term “GTPS” is synonymous to “trochanteric bursitis”, we nowadays accept that this syndrome may result not only by an inflamed bursa, but also by gluteus tendinopathy/tear and external coxa saltans, which refers to ili- otibial band snapping [6–8]. Other rare disorders may also result in GTPS [9–12]. Kong et al. described various findings associated with GTPS, as seen in hip MR imaging examinations and underlined the need of a specific diagnosis in order to optimize the treat- ment strategies [13]. Haliloglu et al. found that T2 peritrochanteric hyperintensity representing edema is by far the most common finding but is rarely related to clinical symptoms [14]. Various stud- ies have reported association between MR imaging findings and the presence of pain [1,15–17]. In the absence of peritrochanteric hyperintensity on fluid sensitive sequences, the GTPS is an unlike diagnosis [15]. On the other hand, large amounts of fluid within bursae, may correlate with clinical presentation [15,18]. No study, to the best of our knowledge, has compared patients with isolated peritrochanteric T2 hyperintensity in the absence of tendinous tears, with patients demonstrating bursitis. More- over, no study has evaluated the role of acetabular morphology in patients with GTPS. We sought to assess the relation of acetabular morphology and NSa with the presence of GTPS and to evaluate the association http://dx.doi.org/10.1016/j.ejrad.2014.06.009 0720-048X/© 2014 Published by Elsevier Ireland Ltd.