title: High tibial osteotomy for the treatment of medial osteoarthritis of the knee with new iBalance system: 2 years of follow-up.
abstract: BACKGROUND
  A new system for performing open-wedge high tibial osteotomy (HTO), the iBalance HTO System-Arthrex, has been recently developed in order to make the surgery more reproducible and safe. The aim of this study was to determine the short-term outcomes of the iBalance technique in medial compartment osteoarthritis and varus malalignment of the knee.
  
  
  METHODS
  Fifteen patients with a mean age of 50.7 years (SD 5.09), affected by symptomatic varus knee, with medial compartment osteoarthritis (1-2 Ahlbäck degree), were treated with iBalance HTO between July 2011 and February 2012 and evaluated retrospectively. Patients were assessed against the following benchmarks: subjective International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and VAS for pain and Tegner scores, along with X-rays and MRI, before surgery and after a 2-year follow-up.
  
  
  RESULTS
  No severe intraoperative complications or implant failures occurred. The mean preoperative scores were as follows: subjective IKDC 66.8 (SD 1.18), KOOS 61.3 (SD 0.86), Vas for pain 8.6 (SD 1.72) and Tegner 4.1 (SD 2.06), while at follow-up the scores were 73.6 (SD 1.01), 88.1 (SD 1.23), 2.9 (SD 2.35) and 3.1 (SD 1.83), respectively. Correction ranged between 3° and 8°. All patients showed complete articular recovery, no loss of correction, no substantial variation in A/P slope and no hardware problems.
  
  
  CONCLUSIONS
  iBalance proved to be effective and safe and produced good overall results. Consolidation and osseointegration of the system took place rapidly, while recovery was precocious, comparable with traditional methods and with no severe complications.
  
  
  METHODS
  Case series, Level IV.
authors.affiliation: San Marino ISS - State Hospital, Via Vittorio Scialoja no 40, 47893, Borgo Maggiore, CA, San Marino.
authors.forename: Diego
authors.initials: D
authors.lastname: Ghinelli
authors.affiliation: Rizzoli Orthopaedic Institute, Via Pupilli, 1, 40134, Bologna, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Parma
authors.affiliation: Rizzoli Orthopaedic Institute, Via Pupilli, 1, 40134, Bologna, Italy. dr.mbaldassarri@gmail.com.
authors.forename: Matteo
authors.initials: M
authors.lastname: Baldassarri
authors.affiliation: Rizzoli Orthopaedic Institute, Via Pupilli, 1, 40134, Bologna, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Olivieri
authors.affiliation: Rizzoli Orthopaedic Institute, Via Pupilli, 1, 40134, Bologna, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Mosca
authors.affiliation: Rizzoli Orthopaedic Institute, Via Pupilli, 1, 40134, Bologna, Italy.
authors.forename: Gherardo
authors.initials: G
authors.lastname: Pagliazzi
authors.affiliation: Rizzoli Orthopaedic Institute, Via Pupilli, 1, 40134, Bologna, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Buda
mesh_terms: D000328:Adult; D017760:Bone Malalignment / Q000150:complications*; D001860:Bone Plates; D000069343:Bone-Implant Interface; D005260:Female; D006801:Humans; D007558:Italy; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D010027:Osteotomy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000517:prevention & control; D011859:Radiography / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome
keywords: High tibial osteotomy; Open wedge; iBalance