Introduction

Various anti-infective agents can be added to the surface of orthopaedic implants to actively kill bacteria and prevent infection. Silver (Ag) is a commonly used agent in various anti-infective applications. Silver disrupts bacterial membranes and binds to bacterial DNA and to the sulfhydryl groups of metabolic enzymes in the bacterial electron transport chain, thus inactivating bacterial replication and key metabolic processes. Recently we are implanting Silver coated megaprosthesis for the treatment of post-traumatic septic non unions/bone defects and for infected hip or knee prosthesis revision. We treat these complications utilizing a two steps procedure: 1° step: devices removal, resection, debridment and antibiotic spacer implantation; 2° step: spacer removal and megaprosthesis implantation. This technique produce a reactive pseudosynovial membrane, well known in traumatology (Masquelet technique), following the Chamber Induction Technique principles. This chamber creates the perfect environment in which implant the prosthesis with safety. We are nowadays investigating if this membrane could optimize the Silver antimicrobical effects reducing the Silver ions dispersion and reducing toxicity on the human body.

Introduction

Throughout the world the number of large joint arthroprosthetic implants continues to increase and consequently the number of septic complications with prosthesis mobilizations, periprostehtic bone loss or non-unions. The implant of large resection prosthesis (megaprosthesis) in selected patients could be a good solution both in hip and knee infected prosthesis with bone defects.

The two stage techniques with a first operation to debride, prosthesis components removal and antibiotic spacer implantation followed by a subsequent final prosthetic implant offer great results even in highly complex patients.

Introduction

In orthopaedics one of the most common complications is infection. The occurrence of a postoperative infection significantly increases the failure rate; both in the case of prosthetic and trauma surgery. Some patients despite a meticulous antiseptic procedures, a close monitoring of controls peri- and post-operative undergo the development of infection of the fixation devices with the risk of developing osteomyelitis. This risk is highly increased in the distal leg because of the known problems with blood supply and poor muscle coverage. The functionality of the affected segment is impaired, quoad fuctionem, with increased risk of amputation and sometimes with poor prognosis, quoad vitam. The therapeutic strategy proposed by our group is to treat an osteomyelitic site as a pseudo-tumor with a megaimplant following a ladder strategy driven by the NUSS classification. This work shows our experience with a developing system by Waldemar-LINK highlighting critical issues and preliminary results.

INTRODUCTION

The hip arthroplasty implant is currently growing up both in orthopedic and trauma practice. This increases the frequency of prosthesis revision due to implant loosening often associated with periprosthetic osteolysis that determine the failure and lead to a loss of bone substance. Nowadays there are numerous biotechnologies seeking to join or substitute the autologous or omologous bone use. These biotechnologies (mesenchymal stromal cells, growth factors and bone substitutes) may be used in such situations, however, the literature doesn't offer class 1 clinical evidences in this field of application.