title: Precise and feasible measurements of lateral calcaneal lengthening osteotomies by radiostereometric analysis in cadaver feet.
abstract: OBJECTIVE
  Lengthening osteotomies of the calcaneus in children are in general grafted with bone from the iliac crest. Artificial bone grafts have been introduced, however, their structural and clinical durability has not been documented. Radiostereometric analysis (RSA) is a very accurate and precise method for measurements of rigid body movements including the evaluation of joint implant and fracture stability, however, RSA has not previously been used in clinical studies of calcaneal osteotomies. We assessed the precision of RSA as a measurement tool in a lateral calcaneal lengthening osteotomy (LCLO).
  
  
  METHODS
  LCLO was performed in six fixed adult cadaver feet. Tantalum markers were inserted on each side of the osteotomy and in the cuboideum. Lengthening was done with a plexiglas wedge. A total of 24 radiological double examinations were obtained. Two feet were excluded due to loose and poorly dispersed markers. Precision was assessed as systematic bias and 95% repeatability limits.
  
  
  RESULTS
  Systematic bias was generally below 0.10 mm for translations. Precision of migration measurements was below 0.2 mm for translations in the osteotomy.
  
  
  CONCLUSIONS
  RSA is a precise tool for the evaluation of stability in LCLO. Cite this article: Bone Joint Res 2015;4:78-83.
authors.affiliation: Department of Children's Orthopaedics, Aarhus University Hospital, Nørrebrogade 44, Building 1A, 2nd floor, 8000, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Martinkevich
authors.affiliation: Department of Children's Orthopaedics, Aarhus University Hospital, Nørrebrogade 44, Building 1A, 2nd floor, 8000, Denmark.
authors.forename: O
authors.initials: O
authors.lastname: Rahbek
authors.affiliation: Department of Children's Orthopaedics, Aarhus University Hospital, Nørrebrogade 44, Building 1A, 2nd floor, 8000, Denmark.
authors.forename: B
authors.initials: B
authors.lastname: Møller-Madsen
authors.affiliation: Aarhus University Hospital, Tage-Hansens Gade 4, 8000 Aarhus C, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Søballe
authors.affiliation: Aarhus University Hospital, Palle Juul-Jensens Boulevard 82, 8200 Aarhus N, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Stilling
keywords: Flatfoot; Calcaneal osteotomy; Radiostereometric analysis; precision