title: Efficacy of periprosthetic erythromycin delivery for wear debris-induced inflammation and osteolysis.
abstract: OBJECTIVE
  We have reported that oral erythromycin (EM) inhibits periprosthetic tissue inflammation in a group of patients with aseptic loosening. The purpose of this study was to assess the efficacy of local, periprosthetic EM delivery in a rat model.
  
  
  METHODS
  Uncoated Ti pins were press-fit into the right tibia of fourteen Sprague-Dawley rats following an intramedullar injection of UHMWPE (ultra high molecular weight polyethylene) particles. Revision surgeries were performed 2 months after the primary surgery. EM was applied to the Peri-Apatite™ (PA) layer of the titanium (Ti) pins. The previously implanted Ti pins were withdrawn and replaced with Ti pins coated either with (n = 7) or without (n = 7) EM. The rats were killed 1 month after "revision surgery". The EM efficacy was evaluated by (MicroCT) μCT and histology.
  
  
  RESULTS
  μCT analysis showed that bone volume percentage (BV/TV) was significantly higher in the EM-treated group compared to the untreated group (p < 0.05). Histological analysis showed that EM treatment inhibits UHMWPE particle-induced periprosthetic tissue inflammation compared to the untreated group.
  
  
  CONCLUSIONS
  This study demonstrated that periprosthetic EM delivery reduced periprosthetic inflammation and improved the quality of surrounding bone.
authors.affiliation: Department of Orthopaedic Surgery, Detroit Medical Center and Providence Hospital Orthopaedic Residency, Detroit, MI, USA. wren@med.wayne.edu
authors.forename: Weiping
authors.initials: W
authors.lastname: Ren
authors.forename: Renwen
authors.initials: R
authors.lastname: Zhang
authors.forename: Monica
authors.initials: M
authors.lastname: Hawkins
authors.forename: Tong
authors.initials: T
authors.lastname: Shi
authors.forename: David C
authors.initials: DC
authors.lastname: Markel
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D020099:Coated Materials, Biocompatible / Q000378:metabolism; D004917:Erythromycin / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D020007:Implants, Experimental; D007249:Inflammation / Q000188:drug therapy / Q000209:etiology / Q000473:pathology; D010014:Osteolysis / Q000188:drug therapy / Q000209:etiology / Q000473:pathology; D011095:Polyethylenes / Q000378:metabolism; D011475:Prosthesis Failure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013977:Tibia / Q000473:pathology; D014025:Titanium / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene; D004917:Erythromycin; D014025:Titanium