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. Between January 2008 and January 2016 we have treated 55 patients with septic post-traumatic bone defects In 48/55 cases we perform a 2 steps procedure: 1° step: resection, debridment, devices removal and antibiotic spacer implantation; 2° step: spacer removal and megaprosthesis implantation. In 7/55 patients in whom all the femur was infected, we performed a one step procedure by the complete removal of the femur and a megaprosthesis (Total Femur) implantation.INTRODUCTION
MATERIAL AND METHOD
After a few years from its introduction, the limits of the THA became evident, mainly due to high rates of mobilization for polyethylene wear and to the release of metal ions from MOM and MOP couplings. Ceramic bearings were thus introduced in surgery to obtain lower levels of friction and wear. These issues have now been well recognized by several studies, which show that ceramic-on-ceramic joint has the lowest wear rate among various articulations and that ceramic particles induce less macrophage reaction and decrease cytokine secretion, allowing to have little periprosthetic osteolysis. After the first results in the late 70′s and early 80′s, the mechanical reliability was improved due to the manufacturers' efforts to reduce the ceramic fragility evolving average grain microstructure and lowering the degree of impurity. Betterment and standardization of production have led to 3rd generation alumina, Biolox Forte in 1994, that achieved a lower incidence of fracture. The purpose of our study has been to assess long-term follow-up results of alumina-on-alumina 3rd generation ceramic total hip cementless arthroplasty performed at our institution from January 1995 to December 2000. We prospectively followed more than 200 patients operated of THA for primary or secondary hip osteoarthritis analyzing clinical and radiographs features. In this period, the total hip replacement were performed by a single surgeon, who is the senior author (A.T.) in our Institution. All patients were clinically examined to confirm the diagnosis and all of them were checked with a standard plain radiographs in two projections and, when necessary, the radiographic examination was completed by CT scans. The same prosthesis was used in all patients, a 3rd generation alumina COC articulation, composed of a hemispherical titanium alloy cup and a 28-mm alumina ceramic femoral head. The modular ceramic head was fixed to a 12/14 taper cone. Proximally plasma-spray hydroxyapatite coated Ti alloy stems completes the implant features. Modular necks were used in retro or anteversion and varus or valgus offset, allowing changes in neck-shaft angle and giving a perfect intraoperative stability. Clinical assessment was performed using the Merle-D'Aubigne and Postel hip score. Each patient was assessed before surgery, after 30 days, afterwards at 4 months and annually after surgery. The mode of femoral component fixation was radiographically classified as bone ingrowth fixation, stable fibrous fixation or unstable fixation, according to the criteria Engh-Bobyn. Osteolysis was evaluated on the femoral side at each Gruen zone. Osteolysis on the acetabular side was evaluated by DeLee and Chanley zone. Our study has concluded that cementless modular hip arthroplasty with 3rd generation ceramic-on-ceramic bearing, with a 13 to 18 years follow-up, shows an excellent survivorship, in particular for the very low volume release of microparticles during friction, which consequently reduction of cytokine release, thus diminishing the risk of periprosthetic osteolysis and loosening of implant components.
In Total Knee Arthroplasty (TKA) a proper choice of the implant size is mandatory in order to guarantee the success of the prosthesis, although the tribological behavior TKA is strongly influenced by the implant design. Retrieval analysis of failed total knee prosthesis is essential to investigate the wear mechanism leading to osteolysis and loosening of the implant. Assessments from retrieval studies constitute crucial information in the effort to improve prosthesis functionality and reduce the risk of revision. The aim of the present study was to investigate the correlation among different implant sizes of retrieved TKA and patients' variables such as Body Mass Index (BMI) in terms of surface modifications and morphology change, in order to examine prosthesis properties and performances. In particular, this study can improve the understanding of the tribological behavior of total knee prosthesis and it can help the surgeon to select the best implant size of TKA considering patient's variables. Twelve retrieved total knee prostheses of the same design but with different sizes were investigated. These prostheses were all cemented, fixed and posterior stabilized. These prostheses were explanted from 12 patients after a mean of 3.2 years (from 1.1 to 7.4 years). These patients had undergone a primary TKA at our hospital between 2005 and 2010; there were 10 women and 2 men with a mean age of 68 years (ranging from 48 to 77 years) at implantation. A qualitative assessment of wear patterns and surface damages was performed on femoral components and polyethylene inserts. Roughness analyses were obtained on femoral components to assess surface modifications. Surface roughness of the metallic femoral components was performed with a contact rugosimeter. Following an internal protocol, thirty measurements were acquired from each condyle. Two roughness parameters were take into account: Ra (the Mean Roughness, i.e. the arithmetical mean value of the deviations of the roughness profile about the centre line) and Rsk. (i.e. the skewness, indicates the prevalence of peaks or valleys and quantifies the asymmetry of the profile variation from the mean line). Prostheses time in-vivo and patient details were known.Introduction
Methods
Despite progress in surgical methods, the clinical results of spine fusion are still not satisfactory, although success rate is certainly higher than in the past, some patients require multiple surgeries to treat a spinal disorder. There are many reasons for which a revision surgery may be necessary: for failure of spinal previous fusion, as pseudarthrosis, for junctional failure or for decompensation of previous fusion. This is a review of 54 patients who underwent revision spine fusion between ’96 and 2000: they were 20 males (37%) and 34 females (53%), in 9 (17%) cases was interested cervical segment, in 9 (17%) thoracic, in 10 (18%) thoracolumbar, in 26 (48%) lumbar; in 29 (54%) patients, previous fusion was performed for a fracture, in 23 (42%) for degenerative pathology (in 17 (31%) was made a postero-lateral fusion, in 4 (7%) cases postero-lumbar interbody fusion and in 2 (3%) cases anterior fusion), in 1 (2%) case for degenerative scoliosis and in 1 (2%) case for a tumour excision. Revision surgery had to be performed in 28 (52%) patients for a mechanical complication, in 14 (26%) for instability of device, in 7 (13%) for wound infection and in 5 (9%) for pseudoarthrosis. Revision procedures were in 37 (68%) cases a new spinal fusion (17 (31%) postero-lateral, 7 (13%) postero-lumbar interbody, 7 (13%) anterior fusion and in 6 (11%) cases both anterior in 7 (13%) removal of mechanical devices, in 7 (13%) cleaning of wound and in 3 (5%) elongation of devices. We have performed a clinical and radiological evaluation with al least 2 years of follow-up. From our analysis of results of the present study, it appears that the rates of improvement after a second operation is lower than that after an initial operation and the rates of complication are significantly higher. This is probably relates to the greater complexity of revision surgery, the more invasive nature of procedure and the longer duration. and posterior fusion).
