title: Talofibular Bony Impingement in the Ankle.
abstract: BACKGROUND
  Talofibular bony impingement has not previously been reported, since it is difficult to detect on plain radiograph, similar to the spur on the anterior border of the medial malleolus and anterior portion of the medial talar facet. We hypothesized that talofibular bony impingement can cause limited dorsiflexion of the ankle. The aim of this study was to evaluate talofibular bony impingement as a distinct form of impingement that limits dorsiflexion of the ankle.
  
  
  METHODS
  This study included 20 consecutive patients (21 ankles) with talofibular impingement and 19 consecutive patients (19 ankles) with lateral ankle instability without talofibular impingement. Presence or absence of talofibular impingement was confirmed under direct intraoperative visualization. Dorsiflexion before and after excision of the impinging spurs was measured. Findings on plain radiographs and computed tomography were compared between the groups. Pre- and postoperative clinical assessments were done with Foot Function Index, visual analog scale for pain, and American Orthopaedic Foot & Ankle Society ankle-hindfoot score at a mean follow-up of 1.4 years.
  
  
  RESULTS
  After removal of the bony impingement, the range of dorsiflexion increased by a mean 7.9 degrees (range, 2.5 to 11.0 degrees) in the impingement group. The mean distance between the fibula and lateral process of the talus on weight- bearing anteroposterior radiograph of the ankle was 1.2 mm (range, 0 to 4.5) in the impingement group and 3.2 mm (range, 1 to 4.5) in the control group. On axial computed tomography image, bony protrusion of the lateral process of the talus was frequently present in the impingement group, and the mean amount of protrusion was more than that of the control group. Clinical findings improved overall.
  
  
  CONCLUSIONS
  Talofibular impingement was a cause of limited dorsiflexion, and the diagnosis was confirmed intraoperatively.
  
  
  METHODS
  Level III, retrospective comparative study.
authors.affiliation: Department of Orthopaedic Surgery, Uijeongbu St Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijenong bu si, Gyeonggi-do, Republic of Korea.
authors.forename: Ji-Yong
authors.initials: JY
authors.lastname: Ahn
authors.affiliation: Department of Orthopaedic Surgery, Haeundae Paik Hospital, Inje University, Busan, South Korea.
authors.forename: Hong-Joon
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Department of Orthopaedic Surgery, Seoul Paik Hospital, Institute for Research of Foot and Ankle Diseases, Inje University, Seoul, South Korea leewoochun@gmail.com.
authors.forename: Woo-Chun
authors.initials: WC
authors.lastname: Lee
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D005360:Fibula / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology / Q000601:surgery*; D017844:Lateral Ligament, Ankle / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D019637:Orthopedic Procedures / Q000379:methods; D054850:Osteophyte / Q000000981:diagnostic imaging / Q000601:surgery*; D010147:Pain Measurement; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function; D013628:Talus / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult
keywords: ankle; computed tomography; limited dorsiflexion; plain radiographs; talofibular impingement