title: Surgical correction of the ball and socket ankle joint in the adult associated with a talonavicular tarsal coalition.
abstract: BACKGROUND
  Ball and socket ankle (BASA) deformity is a rare condition. Little is known about outcomes and treatments in the adult population.
  
  
  METHODS
  Retrospective comparative review was performed of 13 patients treated for BASA with a minimum follow-up of 2.5 years. Evaluation included clinical and radiographic review, outcome scores, a questionnaire, and a subjective satisfaction survey.
  
  
  RESULTS
  Nine patients with correctable valgus deformity not associated with arthritis of the ankle joint underwent a supramalleolar osteotomy (SMO). Four patients underwent arthrodesis-2 a tibiotalocalcaneal (TTC) arthrodesis and 2 a pantalar arthrodesis. AOFAS scores improved from 30.1 to 77.6 (range, 16-82) (P < .05) in the SMO group. AOFAS scores improved from 24 to 60.5 (range, 16-66) (P < .05) in the arthrodesis group. Arthritis grade in the SMO patients was unchanged in 4 patients at final follow-up and worsened in 5 patients by only 1 grade. Nine patients reported good results (all 4 arthrodesis patients, 5 SMO patients) and 4 reported fair results (all SMO patients).
  
  
  CONCLUSIONS
  BASA deformity and dysfunction can be improved with corrective surgery.
  
  
  METHODS
  Level III, prospective comparative study.
authors.affiliation: OrthoCarolina, Foot and Ankle Institute, Charlotte, NC, USA.
authors.forename: J Kent
authors.initials: JK
authors.lastname: Ellington
authors.forename: Mark S
authors.initials: MS
authors.lastname: Myerson
mesh_terms: D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D001168:Arthritis / Q000601:surgery; D005260:Female; D005532:Foot Deformities, Congenital / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D011446:Prospective Studies; D011859:Radiography; D012189:Retrospective Studies; D013628:Talus / Q000002:abnormalities* / Q000601:surgery; D055815:Young Adult
keywords: ankle deformity; arthritis; arthrodesis; ball and socket ankle; osteotomy