title: Total Arthroplasty of the Metatarsophalangeal Joint of the Hallux.
abstract: BACKGROUND
  The current gold standard in the treatment of severe hallux rigidus is arthrodesis of the first metatarsophalangeal (MTP-I) joint. We present the results of a new 3-component MTP-I prosthesis. We determined (1) the intraoperative and perioperative complications; (2) survivorship of prosthesis components and rate of secondary surgeries for any reason; (3) prosthetic component stability and radiographic alignment; (4) the degree of pain relief; and (5) the midterm functional outcomes including radiographic range of motion (ROM).
  
  
  METHODS
  From 2008 to 2010, we prospectively included 29 MTP-I prostheses in 25 patients. The average age of the patients was 63.1 years (range, 48-87 years). The average follow-up was 49.5 months (range, 36-62 months). We observed complications and reoperations. A visual analog scale for pain and the American Orthopaedic Foot & Ankle Society (AOFAS) forefoot score were obtained pre- and postoperation. Component stability and alignment were assessed using weight-bearing radiographs. Fluoroscopy was used to determine radiographic MTP-I ROM.
  
  
  RESULTS
  Seven (24.1%) patients underwent 1 or more secondary surgeries. Four cases (13.7%) eventually had a conversion to MTP-I arthrodesis. Two patients (3 cases) died from causes not related to the procedure. This left 22 feet in 19 patients for final follow-up. All but 3 remaining prostheses showed stable osteointegration and no migration, but MTP-I alignment showed high variability. The average pain score decreased from 5.9 (range, 3-9) to 1.2 (range, 0-5). The average AOFAS forefoot score increased from 55 (range, 0-80) to 83.5 (range, 58-95). Range of motion initially increased from 37.8 degrees (range, 0-60 degrees) to 88.6 degrees (range, 45-125 degrees) intraoperatively and decreased to 29.0 degrees (range, 11-52 degrees) at latest follow-up.
  
  
  CONCLUSIONS
  Our data suggest that total arthroplasty of MTP-I leads to a high amount of revision surgeries, but the remaining patients had significant pain relief at midterm follow-up. However, we observed high variability regarding the prosthesis component alignment and poor range of motion.
  
  
  METHODS
  Level IV, prospective cohort study.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Basel, Basel, Switzerland monika.horisberger@usb.ch.
authors.forename: Monika
authors.initials: M
authors.lastname: Horisberger
authors.affiliation: Department of Orthopaedic Surgery, University Hospital of Basel, Basel, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Haeni
authors.affiliation: Department of Orthopaedics, Harold K. Dunn Orthopaedic Research Laboratory, University of Utah, Salt Lake City, UT, USA.
authors.forename: Heath B
authors.initials: HB
authors.lastname: Henninger
authors.affiliation: Department of Orthopaedics and Traumatology, Schmerzklinik Basel, Basel, Switzerland.
authors.forename: Victor
authors.initials: V
authors.lastname: Valderrabano
authors.affiliation: Department of Orthopaedics, University of Utah, Salt Lake City, UT, USA.
authors.forename: Alexej
authors.initials: A
authors.lastname: Barg
mesh_terms: D019643:Arthroplasty, Replacement / Q000379:methods*; D006214:Hallux / Q000601:surgery*; D020859:Hallux Rigidus / Q000601:surgery*; D006801:Humans; D007595:Joint Prosthesis / Q000592:standards*; D008683:Metatarsophalangeal Joint / Q000601:surgery*; D010147:Pain Measurement; D017060:Patient Satisfaction; D011446:Prospective Studies; D011859:Radiography / Q000379:methods*; D016059:Range of Motion, Articular; D016474:Weight-Bearing
keywords: hallux rigidus; metatarsophalangeal joint; prosthesis