title: Computer tomography prototyping and virtual procedure simulation in difficult cases of hip replacement surgery.
abstract: Each year approximately 1 million total hip replacements (THR) are performed worldwide. A percentage of failure due to surgical approach and imprecise implant placement still exists. These result in several serious complications. We propose an approach to plan, to simulate, and to assist prosthesis implantation for difficult cases of THR based on 3-D virtual models, generated by segmenting patients' CT images, 3-D solid models, obtained by rapid prototyping (RP), and virtual procedure simulation. We carried out 8 THR with the aid of 3-D reconstruction and RP. After each procedure a questionnaire was submitted to the surgeon to assess the perceived added value of the technology. In all cases, the surgeon evaluated the 3-D model as useful in order to perform the planning. The clinical results showed a mean increase in the Harris Hip Score of about 42.5 points. The mean time of prototyping was 7.3 hours, (min 3.5 hours, max 9.3 hours). The mean surgery time was 65 minutes (min 50 minutes, max 88 minutes). Our study suggests that meticulous preoperative planning is necessary in front of a great aberration of the joint and in absence of normal anatomical landmarks, CT scan is mandatory, and 3-D reconstruction with solid model is useful.
authors: 1st Orthopaedic Department University of Pisa, Pisa, Italy.
authors: Paolo Domenico
authors: PD
authors: Parchi
authors: EndoCAS Center for Computer Assisted Surgery University of Pisa, Pisa, Italy.
authors: Vincenzo
authors: V
authors: Ferrari
authors: 1st Orthopaedic Department University of Pisa, Pisa, Italy.
authors: Nicola
authors: N
authors: Piolanti
authors: 1st Orthopaedic Department University of Pisa, Pisa, Italy.
authors: Lorenzo
authors: L
authors: Andreani
authors: EndoCAS Center for Computer Assisted Surgery University of Pisa, Pisa, Italy.
authors: Sara
authors: S
authors: Condino
authors: 1st Orthopaedic Department University of Pisa, Pisa, Italy.
authors: Gisberto
authors: G
authors: Evangelisti
authors: Chief of the 1st Orthopaedic Department of Pisa University of Pisa, Pisa, Italy.
authors: Michele
authors: M
authors: Lisanti
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D003198:Computer Simulation; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008954:Models, Biological; D011300:Preoperative Care / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D014584:User-Computer Interface