INTRODUCTION

Recently the evolution of prosthesis technology allows the surgeon to replace entire limbs. These special prostheses or megaprostheses were born for the treatment of severe oncological bone loss. Recently, however, the indications and applications of these devices are expanding to other orthopaedic and trauma situations. Since some years we are implanting megaprostheses in non-oncological conditions such as septic post-traumatic failures represented by complex non-unions and critical size bone defects.

The purpose of this study is to retrospectively evaluate the clinical outcome of this treatment and register all the complications and infection recurrence.

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.

Introduction

Our department is responsible specifically for complex cases resulting from trauma. Our experience does not want to add what has been clearly demonstrated by multicenter studies on the efficacy of rivaroxaban but aims to demonstrate how the use of this molecule was effective also in mega-prosthesis and how it has proven to be flexible and safe in dealing with difficulties and surgical complications more common in such difficult cases.

Introduction

The development of new megaprosthesis for the treatment of large bone defects has offered important opportunities to orthopedic oncologic surgeons for the replacement of skeletal segments such as the long bones of the upper and lower limbs and the relative joints. Our experience, treating non union and severe bone loss, has brought us, sometimes, to be confronted with the reality of some failures after unsuccessful attempts to reconstruct. Faced with certain radiological and / or clinical drastic situations we wanted to apply the principles of Biological Chamber and oncologic surgery with megaprosthetic replacement solutions. We implanted megaprosthesis with either 1 step or 2 steps (previous antibiotated spacer) technique depending on the septic patient conditions. The aim of this study is to retrospectively evaluate both clinical and radiological outcomes in patients underwented to a lower limb megaprosthesis implant and complications were recorded.

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.

Femoral fracture non-unions are considered to be rare, and are usually treated successfully with exchange nailing. However, recalcitrant aseptic cases often require additional bone grafting. The efficacy of BMP-7 in the treatment of recalcitrant aseptic femoral non-unions was studied.

Since 2003 a multicenter registry (bmpusergroup.co.uk) was created collecting details of BMP7 application in general, between different university hospitals across Europe. Demographic data, intraoperative details, complications, clinical outcome parameters, radiological healing, VAS pain score, EuroQol-5D, and return-to-work were prospectively recorded. Radiological healing was defined as the presence of callous in two planes over 3 cortices. The minimum follow up was 12 months.

Seventeen patients, who had undergone a median of 1(1 to 4) prior revision operations, over a median period from the injury of 17 months(9 to 42), were included in this observational study. In 76.4%(13/17) the BMP7 was combined with revision of the fixation. Non-union healing was verified in 14/17 cases(82.3%) in a median period of 6.5 months(3–15). Over 80% of these patients returned to their pre-injury level of activities, the median overall health state score was 82.5(35 to 100). No adverse events or complications were associated with the BMP7 application over the median follow-up of 24 months(12–68).

Purpose: Femoral fracture non-unions are considered to be rare, and are usually treated successfully with exchange nailing. However, recalcitrant aseptic cases often require additional bone grafting procedures. The purpose of this study was to investigate the efficacy of BMP-7 (biological enhancement) in the treatment of recalcitrant aseptic femoral non-unions.

Material & Methods: Since 2003 a multicenter registry (bmpusergroup.co.uk) was created to collect details of BMP7 application in general, between different university hospitals across Europe. Demographic data, intraoperative details, complications, clinical outcome parameters, radiological healing, VAS pain score, EuroQol-5D, and return-to-work were prospectively recorded. Radiological healing was defined as the presence of callous in two planes over 3 cortices. The minimum follow up was 12 months.

Results: Thirty patients, who had undergone a median of 1 (1 to 5) prior revision operations, over a median period from the injury of 24 months (9 to 65), were included in this observational study. In 76.7% (23/30) the application of BMP7 was combined with a revision of the fixation. Non-union was verified in 26/30 cases (86.7%) in a median period of 6 months (range 4–10). Over 70% of these patients returned to their preinjury level of activities, the median overall health state score was 82.5 (45 to 95). No adverse events or complications were associated with the BMP7 application over the median follow-up of 30 months (12–68).

Discussion/Conclusion: This case series has verified the safety and efficacy of the use of BMP7 in a manner comparable to the scarce existing evidence on femoral non-unions. The establishment of multicenter networks and the systematic and long-term follow-up of these patients are expected to provide further information and significantly improve our understanding on this promising osteoinductive bone substitute.

Aims: The treatment of long bone non-union now days finds its gold standard in autologous bone grafting. Since this technique is affected by a high morbidity rate of the donor site, many studies tried to find valid alternatives to this procedure, but during the last few years the advances made in tissue engineering techniques opened new frontiers.

In this study BMPs/AGFs were used in posttraumatic long bone non-union and osseous defects to test their clinical and radiological effectiveness in order to find a valid alternative to autologous bone grafting.

Methods: The cases selected can be divided in two groups. Group A: Patients affected by long bones Non Union, 9 months minimum duration, who are judged not to heal by simply changing the osteosynthesis device. Group B: Patients with non neoplastic, posttrauma or post-resection osseous defects of a critical size that will probably not heal using traditional surgical techniques or for which such techniques are considered to be unsuitable.

Moreover, the overall recruitment period is 3 years during which 40 patients/year will be enrolled up to a total of 120 cases; half of these will be treated with rhBMP-7 and the other half with PRP.

Results: Only 66 patients can be evaluated as they have completed the minimum follow-up period of 9 months, 35 of whom have been treated with rhBMP-7 and 31 treated with PRP. Advanced results indicate the RX Healing rate was 85% for BMP-7 and 68% for PRP with a Clinical Healing rate of 88.5% and 68%; therefore a higher efficiency of BMP-7 over PRP was found, confirmed by a significant failure rate of 15% versus 32,3% between BMP-7 and PRP, respectively.

Conclusions: According to our results, the use of growth factors showed a similar effectiveness to autologous bone grafting with better tolerability, moreover, a relevant difference in healing/failure rate between rhBMP-7 and PRP is observed.