title: Acute lateral dislocation of the patella: correlation of ultrasound scanning with operative findings.
abstract: Acute lateral dislocation of the patella has been associated with disruption of the medial restraints of the patella. Following non-operative management there is a re-dislocation rate of up to 44%. The purpose of this study was to test whether sonography is a reliable method of assessing the medial retinaculum after acute dislocation of the patella. Ten patients following acute patellar dislocation had an ultrasound scan (USS) performed by an experienced musculoskeletal radiologist. Each patient subsequently had an examination under anaesthetic, arthroscopy, and repair of the ruptured structures. The ultrasound reports were compared to the surgical findings to determine the accuracy of this investigation. USS located deficiencies in the ligamentous attachments to the medial border of the patella and the presence of avulsed bony fragments, all of which were confirmed at operation. The sonographic diagnosis of haematoma or torn fibres in the vastus medialis obliquus (VMO) corresponded with our operative findings. The most significant findings were the correlation of free fluid around the medial collateral ligament (MCL) with avulsion of the femoral attachment of the medial patellofemoral ligament (MPFL) and the presence of avulsed fragments of bone from the medial border of the patella.
authors.affiliation: Department of Orthopaedic Surgery, Kingston NHS Trust, Surrey, UK. ptrikha@doctors.org.uk
authors.forename: S P
authors.initials: SP
authors.lastname: Trikha
authors.forename: D
authors.initials: D
authors.lastname: Acton
authors.forename: M
authors.initials: M
authors.lastname: O'Reilly
authors.forename: M J
authors.initials: MJ
authors.lastname: Curtis
authors.forename: J
authors.initials: J
authors.lastname: Bell
mesh_terms: D000293:Adolescent; D000328:Adult; D001182:Arthroscopy / Q000379:methods; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D010329:Patella / Q000000981:diagnostic imaging / Q000293:injuries*; D017847:Patellar Ligament / Q000000981:diagnostic imaging; D014463:Ultrasonography