title: Mega-granuloma After Using the Universal Clamp for Adolescent Idiopathic Scoliosis: What Is It and Can It Be Prevented?
abstract: METHODS
  Clinical case series.
  
  
  OBJECTIVE
  To characterize the postoperative course and histopathology of peri-implant tissue of adolescent idiopathic scoliosis patients who experienced postoperative development of an aseptic soft tissue reaction, with granulomas adjacent to the sublaminar polyethylene terephthalate strap-titanium clamp used in Zimmer's Universal Clamp (UC) spinal fixation system after spinal surgery.
  The UC was designed for use with spinal deformity procedures in place of pedicle screws, hooks, or sublaminar wiring in fusion constructs. Recent studies of the UC lack emphasis on implant-related postoperative complications.
  
  
  METHODS
  A total of 26 consecutive patients who underwent spinal deformity correction for scoliosis were reviewed for implant-related postoperative complications. Histology, scanning electron microscopy with energy-dispersive X-ray spectroscopy, fractional culture/biopsy, and Gram stain examination of the peri-implant tissue of patients with complications was performed.
  
  
  RESULTS
  The authors reviewed 26 cases for correction of scoliosis. Two patients with adolescent idiopathic scoliosis who used the UC experienced implant-related complications with development of an aseptic soft tissue reaction with granulomas adjacent to the sublaminar polyethylene terephthalate straps-titanium clamp mechanism of the UC 8 months after AIS correction surgery. There were no signs or symptoms of wound infection. Gram stain revealed no organisms. There were many neutrophils and the surface of the wound revealed rare Staphylococcus aureus but the deep portions of the wounds were negative for organisms. Histopathology revealed extensive granulation tissue and histiocytes with engulfed birefringent particles or debris, and scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis revealed macrophages containing many particles identified as titanium.
  
  
  CONCLUSIONS
  adolescent idiopathic scoliosis patients who use the novel UC construct may develop postoperative foreign-body reaction.
authors.affiliation: California Spine, 711 West College Street, Suite 625, Los Angeles, CA 90012, USA. Electronic address: rbailey@jhsph.edu.
authors.forename: Richard Anthony
authors.initials: RA
authors.lastname: Bailey
authors.affiliation: Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, 711 West College Street, Suite 625, Los Angeles, CA 90012, USA.
authors.forename: Jan William
authors.initials: JW
authors.lastname: Duncan
authors.affiliation: Department of Plastic and Reconstructive Surgery, White Memorial Medical Center, 1720 East Cesar Chavez Avenue, Los Angeles, CA 90033, USA.
authors.forename: Alan T
authors.initials: AT
authors.lastname: Tran
authors.affiliation: Department of Pathology, College of Medicine, State University of New York, Upstate Medical University, 750 E. Adams Street, Syracuse, NY 13210, USA.
authors.forename: Jerrold L
authors.initials: JL
authors.lastname: Abraham
keywords: Adolescent idiopathic scoliosis; Granuloma; Polyethylene terephthalate; Titanium implant debris; Universal clamp