Spread of infection, in an animal model, after intramedullary nailing of an infected external fixator pin track

Abstract

Implant sepsis, due to previous external fixator pin track infection, is the most common complication of secondary intramedullary (IM) nailing of the tibia. We have developed an animal model, which allows different treatment methods to be studied. Using an established ovine model of a pin track infection, Stuphylococcus uureus was used to infect the external fixator pins, two weeks prior to reamed IM nailing. In the control group, the animals were killed at a mean of 10.5 days following nailing, when widespread infection was evident, with septic arthritis, abscess formation, and infection of the entire length of the tibia in all six animals. In the treatment group, before IM nailing, the pin sites were dkbrided, and both local and systemic antibiotics were administered. All surgical wounds healed without evidence of infection, 4 of the 6 animals survived for 38 days, and bacteria were only isolated from 1 of the 6 implants. Treatment was successful at reducing, but not eliminating, infection after secondary nailing. 0 2001 Published by

Vancomycin-Modified Implant Surface Inhibits Biofilm Formation and Supports Bone-Healing in an Infected Osteotomy Model in Sheep

“…Orthopaedic models utilizing sheep and goats 37,38 are well accepted because their larger bone and medullary canal sizes allow evaluation of fixation devices (e.g., external fixators and intramedullary nails) that otherwise would need to be modified for use in smaller animals such as rabbits or rats. Establishment of infection has been achieved by either direct inoculation 37 or hematogenous spread 36 . In our model, we consistently achieved infection and a resulting nonunion of the osteotomized tibia in 100% of the control animals.…”

Axial Correction of Pes Varus by Transverse-Opening Wedge Osteotomy and T-Plate Fixation with Beta-Tricalcium Phosphate (.BETA.-TCP) Transplantation in Dachshunds

“…External fixation is widely performed because the procedures involved are relatively simple. However, because the clamps and bars that hold the pins inserted into the bones are outside the body, postoperative management can be complicated and infection at the junction between the skin and the fixation devices becomes an important issue [1,4]. Moreover, as with pes varus, when the bone fragments after osteotomy are small in volume, the thickness and number of pins that can be inserted into the bone fragments are limited, making it difficult to achieve a high degree of fixation strength.…”

Application of locked intramedullary nails in the treatment of complications after distraction osteogenesis

“…17 In an animal experiment in which pin-track infection was followed by reamed intramedullary nailing, the infection was controlled in the group which was managed by debridement and local and systemic administration of antibiotics before nailing, but in the group without such treatment infection spread to the bone marrow and soft tissue. 18 In our series, two patients had infection around half pins at the proximal femur. The pins were removed, the pin-tracks treated and parenteral antibiotics were administered for two weeks before nailing was undertaken.…”