title: An expandable prosthesis with dual cage-and-plate function in a single device for vertebral body replacement: the clinical experience on 14 consecutive cases with vertebral tumors.
abstract: OBJECTIVE
  The aim of this paper was to test the hypothesis that an expandable prosthesis with dual cage-and-plate function can provide immediate and durable spine stabilization after corpectomy.
  
  
  METHODS
  We designed an expandable vertebral body prosthesis with dual cage-and-plate function in a single device (JR-prosthesis). Anatomical studies were performed to design a titanium-made prosthesis. Cadaver assays were done with a stainless steal device to test fixation and adequacy to the human spine anatomy. Then, 14 patients with vertebral tumors (8 metastatic) underwent corpectomy and vertebral body replacement with the JR-prosthesis.
  
  
  RESULTS
  All patients had neurological deficit, severe pain and spine instability (mean follow-up: 25.4 months). Mean pain score before surgery in a visual analog scale improved from 7.6 to 3.0 points after operation (P=0.002). All patients achieved at least one grade of improvement in the Frankel score (P=0.003), excepting the 3 patients with Frankel grade A presurgery. Two patients with renal cell carcinoma died during the following 4 days after surgery (renal failure and massive bleeding), the rest attained a painless and stable spine immediately and maintained for long periods. No significant infections or implant failures were registered. A non-fatal case of inferior vena cava surgical injury was observed (repaired during surgery without further complications).
  
  
  CONCLUSIONS
  The JR-prosthesis stabilizes the spine immediately after surgery and for the rest of the patients' life. To our knowledge, this is the first report on the clinical experience of any expandable vertebral body prosthesis with dual cage-and-plate function in a single device. These observations await confirmation in different scenarios.
authors.affiliation: Department of Orthopedics, Guadalajara University, Jalisco, Mexico. rajj0709@hotmail.com
authors.forename: J J
authors.initials: JJ
authors.lastname: Ramírez
authors.forename: J J
authors.initials: JJ
authors.lastname: Ramírez
authors.forename: E
authors.initials: E
authors.lastname: Chiquete
authors.forename: E
authors.initials: E
authors.lastname: Gómez-Limón
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery; D000328:Adult; D000368:Aged; D001860:Bone Plates; D001943:Breast Neoplasms / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000601:surgery; D002648:Child; D017586:Diskectomy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012516:Osteosarcoma / Q000601:surgery; D010954:Plasmacytoma / Q000601:surgery*; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000379:methods*; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D013125:Spinal Neoplasms / Q000601:surgery*; D014025:Titanium; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014025:Titanium