title: Isolated talonavicular fusion with tension band for Müller-Weiss syndrome.
abstract: BACKGROUND
  There are still controversies with regard to the operative treatment in advanced Müller-Weiss syndrome (MWS), where the navicular undergoes avascular necrosis and the talonavicular (TN) joint becomes arthritic. Most authors advocate extended fusion, sacrificing hindfoot mobility. To restore TN alignment and to achieve stable fixation, we developed a new isolated TN fusion technique applying the principles of a static tension band. The aim of the present study was to report the midterm results of a preliminary series of patients and their clinical and radiographic outcomes.
  
  
  METHODS
  Ten feet (10 patients; 8 females, 2 males; age 63 ± 16.7 [range, 34-83] years) with advanced deformity of MWS (3 Maceira's stage III and 7 stage IV) were treated with isolated TN arthrodesis using the tension band technique. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was used to evaluate the functional outcome. Standard angles were measured to determine the amount of correction achieved through the operative treatment. The minimum follow-up was 24 (range, 24-43) months.
  
  
  RESULTS
  Trabeculation was seen to cross the fusion site on radiographs in 8 patients after 2 and in 1 patient after 3 months. One case needed revision after 13 months due to implant failure; after additional screw fixation, bony healing was achieved 2 months later. At last follow-up, all cases described a high level of satisfaction. Postoperatively, the AOFAS score improved from 33 (range, 18-48) to 88.3 (range, 79-100) (P < .0001) points, the AP talocalcaneal angle increased from 14.2 (range, 1-22) to 22.7 (range, 12-30) degrees (P = .0007), and the calcaneal pitch increased from 10.3 (range, 3-22) to 14.7 (range, 8-22) degrees (P = .0006).
  
  
  CONCLUSIONS
  The static tension band technique is a new, promising technique to treat MWS patients, providing stability against the counteracting deforming forces. Therefore, we consider this technique as our treatment of choice in patients with stage III and stage IV MWS.
  
  
  METHODS
  Level IV, prospective case series.
authors.affiliation: Clinic of Orthopaedic Surgery, Kantonsspital Wolhusen (LUKS), Wolhusen, Switzerland p.fornaciari.med@gmail.com.
authors.forename: Paolo
authors.initials: P
authors.lastname: Fornaciari
authors.affiliation: Clinic of Orthopaedic Surgery, Kantonsspital Baselland, Liestal, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Gilgen
authors.affiliation: Clinic of Orthopaedic Surgery, Kantonsspital Baselland, Liestal, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Zwicky
authors.affiliation: Clinic of Orthopaedic Surgery, Kantonsspital Baselland, Liestal, Switzerland.
authors.forename: Tamara
authors.initials: T
authors.lastname: Horn Lang
authors.affiliation: Clinic of Orthopaedic Surgery, Kantonsspital Baselland, Liestal, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Hintermann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001168:Arthritis / Q000000981:diagnostic imaging / Q000601:surgery; D001174:Arthrodesis / Q000295:instrumentation* / Q000379:methods; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009984:Orthopedic Fixation Devices; D010020:Osteonecrosis / Q000000981:diagnostic imaging / Q000601:surgery; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function; D018570:Risk Assessment; D012494:Sampling Studies; D013577:Syndrome; D013639:Tarsal Bones / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D013640:Tarsal Joints / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Müller-Weiss syndrome; arthrodesis; avascular necrosis; flatfoot; osteonecrosis; tarsal navicular; tension band; varus hindfoot