title: Rate of Malunion Following Bi-plane Chevron Medial Malleolar Osteotomy.
abstract: BACKGROUND
  Access to the medial half of the talus can be challenging even with an osteotomy. Although several techniques are presented in the literature, critical evaluation of fixation, union, and alignment is lacking. The chevron medial malleolar osteotomy provides advantages of perpendicular instrumentation access and wide exposure to the medial talus. Postoperative displacement resulting in malunion, and possibly provoking ankle osteoarthritis, is a known complication. The present study describes our experience with the osteotomy.
  
  
  METHODS
  A consecutive series cohort of 50 bi-plane chevron osteotomies performed from 2004 to 2013 were evaluated. Forty-six were secured using 2 lag screws, and 4 were secured using 2 lag screws and a medial buttress plate. Radiographic studies performed at 2, 6, and 12 weeks and at final follow-up were analyzed for postoperative displacement, malunion, non-union, and hardware-related complications.
  
  
  RESULTS
  At initial postoperative follow-up, 47 of 50 had adequate radiographs for review, and 18 of 47 (38.3%) showed some displacement when compared to the initial osteotomy fixation position. By final follow-up, 15 of 50 (30.0%) had measurable incongruence. Hardware removal was performed in 13 (26.0%) cases at an average of 2.4 years postoperation.
  
  
  CONCLUSIONS
  Bi-plane medial malleolar chevron osteotomy fixed with 2 lag screws showed a 30.0% malunion rate with an average of 2 mm of incongruence on final follow-up radiographs, which is higher than what has been reported in the literature. In our practice, we now use a buttress plate and more recently have eliminated postoperative osteotomy displacement.
  
  
  METHODS
  Level IV, retrospective case series.
authors: Orthopedic Foot and Ankle Center, Westerville, OH, USA.
authors: Patrick E
authors: PE
authors: Bull
authors: Orthopedic Foot and Ankle Center, Westerville, OH, USA ofacresearch@orthofootankle.com.
authors: Gregory C
authors: GC
authors: Berlet
authors: LECOM Bradenton College of Osteopathic Medicine, Bradenton, FL, USA.
authors: Cameron
authors: C
authors: Canini
authors: Orthopedic Foot and Ankle Center, Westerville, OH, USA.
authors: Christopher F
authors: CF
authors: Hyer
mesh_terms: D000843:Ankle Joint / Q000503:physiopathology / Q000601:surgery*; D001863:Bone Screws; D004838:Epiphyses / Q000502:physiology / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D010027:Osteotomy / Q000379:methods*; D011859:Radiography / Q000379:methods*; D012189:Retrospective Studies; D013628:Talus / Q000473:pathology / Q000601:surgery*
keywords: ankle; medial malleolus; medial tibial osteotomy; osteochondral lesion of the talus; surgical approach; talar osteochondral defect