[Effect of vancomycin-loaded polymethylmethacrylate on one-stage revision arthroplasty in treating experimental hemiprosthetic hip infections of rabbits].
OBJECTIVE
To study the effect of vancomycin-loaded polymethylmethacrylate (VCM-PMMA) in the treatment of an experimental hemiprosthetic hip infection of rabbits.


METHODS
The infected hemiprosthetic hip joints of the rabbits underwent debridement and one-stage revision arthroplasty. Requested by the "fixed" method, 24 rabbits were equally divided into 2 groups: the control group and the experimental group. The prostheses were fixed with PMMA in the control group, but with VCM-PMMA in the experimental group. X-ray films were taken immediately after operation, and then 4, 8, and 12 weeks after operation. The C reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) were measured before operation, then measured 1, 3, and 7 days after operation, and then 2, 4, 8, and 12 weeks after operation, i.e., they were measured at the above 8 time points. All the rabbits were sacrificed 12 weeks later. The cure rate of the infection was determined by the blood culture for the corresponding bacteria and the Rhodamine-labeled anti-Staphylococcus epidermidis immune serum staining.


RESULTS
The X-ray films revealed that 6 hemiprosthetic hip joints were dislocated in the control group, but 3 in the experimental group; 58.3% and 16.7% of the hemiprosthetic hip joints were reinfected in the control group and the experimental group, respectively. At 8 weeks in the control group, the serum CRP level decreased to a greater extent than that measured at the time of debridement, but in the experimental group just at 2 weeks (P < 0.01). ESR remained elevated in the control group, but at 4 weeks ESR were significantly lowered compared with that measured at the time of debridement (P < 0.01). The test results for the pathogenic organisms revealed that the re-infection incidences were respectively 58.3% (7/12) and 16.7% (2/12) in the control group and the experimental group, with the successful revision rates of 41.7% and 83.3% respectively in the above 2 groups. The light microscopy revealed that there was a heavy infiltration by the inflammatory cells in the re-infected tissues, but there was a proliferation of the fibrocytes in the tissues of the cured patients.


CONCLUSIONS
One-stage revision arthroplasty can significantly promote the control of the hemiprosthetic hip joint infection in rabbits by the use of VCM-PMMA.
Wang
Ziming
Z
Department of Orthopedic and Traumatic Surgery, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, 400042, PR China.
Wang
Aimin
A
Tang
Guiyang
G
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005270:Femur Head; D006622:Hip Prosthesis / Q000009:adverse effects; D019904:Polymethyl Methacrylate / Q000627:therapeutic use; D016459:Prosthesis-Related Infections / Q000188:drug therapy*; D011817:Rabbits; D014640:Vancomycin / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents; D014640:Vancomycin; D019904:Polymethyl Methacrylate