title: Feasibility of four-dimensional preoperative simulation for elbow debridement arthroplasty.
abstract: BACKGROUND
  Recent advances in imaging modalities have enabled three-dimensional preoperative simulation. A four-dimensional preoperative simulation system would be useful for debridement arthroplasty of primary degenerative elbow osteoarthritis because it would be able to detect the impingement lesions.
  
  
  METHODS
  We developed a four-dimensional simulation system by adding the anatomical axis to the three-dimensional computed tomography scan data of the affected arm in one position. Eleven patients with primary degenerative elbow osteoarthritis were included. A "two rings" method was used to calculate the flexion-extension axis of the elbow by converting the surface of the trochlea and capitellum into two rings. A four-dimensional simulation movie was created and showed the optimal range of motion and the impingement area requiring excision. To evaluate the reliability of the flexion-extension axis, interobserver and intraobserver reliabilities regarding the assessment of bony overlap volumes were calculated twice for each patient by two authors. Patients were treated by open or arthroscopic debridement arthroplasties. Pre- and postoperative examinations included elbow range of motion measurement, and completion of the patient-rated questionnaire Hand20, Japanese Orthopaedic Association-Japan Elbow Society Elbow Function Score, and the Mayo Elbow Performance Score.
  
  
  RESULTS
  Measurement of the bony overlap volume showed an intraobserver intraclass correlation coefficient of 0.93 and 0.90, and an interobserver intraclass correlation coefficient of 0.94. The mean elbow flexion-extension arc significantly improved from 101° to 125°. The mean Hand20 score significantly improved from 52 to 22. The mean Japanese Orthopaedic Association-Japan Elbow Society Elbow Function Score significantly improved from 67 to 88. The mean Mayo Elbow Performance Score significantly improved from 71 to 91 at the final follow-up evaluation.
  
  
  CONCLUSIONS
  We showed that four-dimensional, preoperative simulation can be generated by adding the rotation axis to the one-position, three-dimensional computed tomography image of the affected arm. This method is feasible for elbow debridement arthroplasty.
authors.affiliation: Department of Hand Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan. michi-ya@med.nagoya-u.ac.jp.
authors.forename: Michiro
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of Hand Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Yukimi
authors.initials: Y
authors.lastname: Murakami
authors.affiliation: Department of Hand Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Iwatsuki
authors.affiliation: Department of Hand Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kurimoto
authors.affiliation: Department of Hand Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hirata
mesh_terms: D000368:Aged; D001178:Arthroplasty / Q000009:adverse effects / Q000379:methods*; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D003646:Debridement / Q000009:adverse effects / Q000379:methods*; D004551:Elbow Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D005240:Feasibility Studies; D005260:Female; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications / Q000209:etiology; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome
keywords: Debridement arthroplasty; Elbow osteoarthritis; Four-dimensional simulation