title: Invasiveness Reduction of Recent Total En Bloc Spondylectomy: Assessment of the Learning Curve.
abstract: METHODS
  Case-control study.
  
  
  OBJECTIVE
  To evaluate the surgical magnitude and learning curve of "second-generation" total en bloc spondylectomy (TES).
  
  
  BACKGROUND
  In June 2010, we developed second-generation TES combined with tumor-induced cryoimmunology, which does not require autograft harvesting.
  
  
  METHODS
  TES was performed in 63 patients between June 2010 and September 2013. Three groups of patients were evaluated: 20 undergoing surgery in the first year of development of second-generation TES (group I), 20 in the second year (group II), and 23 in the third year (group III). Patient backgrounds showed no remarkable differences. Operating time, intraoperative blood loss, blood transfusion, and postoperative C-reactive protein and creatine phosphokinase were compared among the groups.
  
  
  RESULTS
  Mean±standard deviation operating time was 486±130 minutes in group I, 441±85 minutes in group II, and 396±75 minutes in group III. The time was significantly shorter in group III than in group I (p<0.05). Intraoperative blood loss was 901±646 mL in group I, 433±177 mL in group II, and 411±167 mL in group III. Blood loss was significantly lower in groups II and III than in group I (p<0.01). Transfusion was not required in 20 of 23 patients in group III, and mean C-reactive protein levels on postoperative day 3 were significantly lower in this group than in group I (6.12 mg/L vs. 10.07 mg/L; p<0.05). Postoperative creatine phosphokinase levels did not differ among the groups.
  
  
  CONCLUSIONS
  TES is associated with a significant learning curve. Thus, second-generation TES can no longer be considered highly invasive.
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ishii
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Murakami
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Demura
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kato
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Katsuhito
authors.initials: K
authors.lastname: Yoshioka
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Moriyuki
authors.initials: M
authors.lastname: Fujii
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Igarashi
authors.affiliation: Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuchiya
keywords: Learning curve; Total en bloc spondylectomy