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Skeletal Radiol (2008) 37:451455 DOI 10.1007/s00256-008-0450-7
SCIENTIFIC ARTICLE
MRI findings of prepatellar Morel-Lavalle effusions
Camilo G. Borrero & Norman Maxwell & Eoin Kavanagh
Received: 2 October 2007 /Revised: 9 December 2007 /Accepted: 26 December 2007 /Published online: 13 February 2008 # ISS 2008
AbstractObjective To describe MR imaging characteristics and treatment options for prepatellar closed degloving injuries or Morel-Lavalle effusions. Imaging features are discussed that may aid in the distinguishing of this entity from housemaid's knee or prepatellar bursitis.
Materials and methods MR images of four young wrestlers were reviewed by two attending radiologists and one fellow, and correlative clinical data were collected using the electronic medical database.
Results MR images in all cases showed a unilocular, T2 hyperintense prepatellar collection extending beyond the normal boundaries of the prepatellar bursa. No necrotic fat or blood products were identified in the collections. Surgical pathology proving the absence of synovial tissue was available for one case, and differentiation of the collection from the adjacent bursa was confirmed visually by the surgeon in a second case.
Conclusion Although prepatellar hemorrhagic bursitis and Morel-Lavalle effusions share many imaging features, making a specific diagnosis in most cases is not necessary, as treatment is often similar for both entities.
Keywords Knee . Morel-Lavalle degloving injury. MRI
Introduction
Closed degloving injuries of the soft tissues overlying the hip and pelvis were first described by the French physician Maurice Morel-Lavalle in 1853 [1, 2]. These injuries have
been reported to involve the soft tissues adjacent to the greater trochanter, lower back, and buttock regions [36]. Typically, these injuries are manifested as fluid collections at the interface between the subcutaneous fat and underlying fascia, with variable appearances on MRI [4]. Although Morel-Lavalle lesions (MLLs) have been described in the knee in the orthopedic literature [6], to our knowledge, a case series describing the imaging findings of MLLs of the knee has never been reported in the radiology literature.
We describe the MR imaging features of prepatellar collections in four young wrestlers, with two cases proven with surgical inspection and pathological analysis and two cases suggested by imaging alone. Imaging features that might aid in distinguishing between prepatellar bursitis and MLL are suggested.
Case reports
Case 1
An 18-year-old male presented with left knee pain...