Resection of the proximal femur raises several challenges to the orthopedic oncology surgeon. Among these is the re-establishment of the abductor mechanism that might impacts on hip function. Extent of tumor resection and surgeons’ preferences dictate the reconstruction method of the abductors. While some surgeons advocate the necessity of greater trochanter (GT) preservation whenever possible, others attempt direct soft tissues reattachment to the prosthesis. Sparse data in the literature evaluated the outcomes of greater trochanter fixation to the proximal femur megaprosthesis. This is a retrospective monocentric study. All patients who received a proximal femoral replacement after tumor resection between 2005 and 2021 with a minimum follow-up of three months were included. Patients were divided into two groups: (1) those with preserved GT reattached to the megaprosthesis and (2) those with direct or indirect (tenodesis to fascia lata) abductor muscles reattachment. Both groups were compared for surgical outcomes (dislocation and revision rates) and functional outcomes (Trendelenburg gait, use of walking-assistive device and abductor muscle strength). Additionally patients in group 1 were subdivided into patients who received GT reinsertion using a grip and cables and those who got direct GT reinsertion using suture materials and studied for GT displacement at three, six and 12 months. Time to cable rupture was recorded and analyzed through a survival analysis. Fifty-six patients were included in this study with a mean follow-up of 45 months (3-180). There were 23 patients with reinserted GT (group 1) and 33 patients with soft tissue repair (group 2). Revision rate was comparable between both groups(p=0.23); however, there were more dislocations in group 2 (0/23 vs 6/33; p=0.037). Functional outcomes were comparable, with 78% of patients in group 1 (18/23) and 73% of patients in group 2 (24/33) that displayed a Trendelenburg gait (p=0.76). In group 1, 70% (16/23) used walking aids compared to 79% of group 2 (27/33) (p=0.34). Mean abductor strength reached 2.7 in group 1 compared to 2.3 in group 2 (p=0.06). In group 1, 16 of the 23 patients had GT reinsertion with grip and cables. Median survival of cables for these 16 patients reached 13 months in our series. GT displacement reached a mean of two mm, three mm, and 11 mm respectively at three, six and 12 months of follow-up in patients with grip and cables compared to 12 mm, 24 mm and 26 mm respectively at the same follow-up intervals in patients with GT stand-alone suture reinsertion(p<0.05). Although GT preservation and reinsertion did not improve functional outcomes after proximal femur resection and reconstruction with a megaprosthesis, it was significantly associated with lower dislocation rate despite frequent cable failure and secondary GT migration. No cable or grip revision or removal was recorded. Significantly less displacement was observed in patients for whom GT reattachment used plate and cables rather than sutures only. Therefore we suggest that GT should be preserved and reattached whenever possible and that GT reinsertion benefits from strong materials such as grip and cables

Aim. Megaprosthesis have become a standard option in limb preserving surgery after bone resection in musculoskeletal tumors. Recently they have also been used in complex revision arthroplasty in cases with massive bone loss. The aim of this study was to analyze the incidence of periprosthetic joint infection (PJI) both in primary oncology cases and aseptic revision cases and analyze which are the significant risk factors for PJI with a special interest on the use of prophylactic antibiotic loaded calcium sulfate beads. Method. All patients undergoing surgery with the use of megaprosthesis in our institution between January/2012 and December/2022 were retrospectively reviewed. Data was collected from electronic medical records. We identified 108 procedures involving megaprosthesis in 90 patients with an average follow-up of 37 months. Indications were 79 primary musculoskeletal tumors and 29 aseptic complex revision arthroplasty. Results. Table 1 shows relevant clinical information. No significant risk factor was found either in uni or multivariate analysis. PJI rate was 15% (12/79) for primary musculoskeletal surgery and 31% (9/29) for complex revision surgery. The use of antibiotic loaded calcium sulfate beads did not show an advantage – 22% (9/41) with vs. 18% (12/67) without. Conclusions. In this relatively small series it was not possible to show a significal association between PJI and certain known risk factors such as gender, ASA score, site of surgery (knee) and revision surgery. The use of antibiotic loaded calcium sulfate beads as prophylaxis was not beneficial in reducing PJI rates in our cohort. We acknowledge the limitations of our study: a small sample group, in a single institution with heterogeneity in terms of diagnosis and surgical site. We recognize the need for a multicentric study with a larger cohort to validate these findings. For any tables or figures, please contact the authors directly

Aim. Periprosthetic joint infections are a devastating complication after modular endoprosthetic reconstruction following resection of a musculoskeletal tumour. Due to long operating times, soft tissue dissection and immunosuppression, the infection rate after limb salvage is high and ranges between 8% and 15%. The aim of this retrospective single centre study was to assess the reinfection and re-reinfection rate after septic complications of megaprostheses. Method. In this retrospective study, 627 patients with a primary replacement of a musculoskeletal tumour of the lower limb and reconstruction by a megaprosthesis were recorded from 1983 – 2016. 83 out of 621 patients available for follow-up experienced an infection (13.4%). Two patients were treated with debridement and removal of the mobile parts, 61 patients with a one-stage revision, 16 patients with a two-stage revision, and 4 patients with an amputation. The mean follow up was 133 months (range: 2 – 423 months). Results. The reinfection rates after debridement, one-stage revision, two-stage revision, and amputation were 100% (CI 95%: 20 −100%), 49% (CI 95%: 36 – 62%), 38% (CI 95%: 6 – 76%), and 0%, respectively. A reinfection occurred after a mean of 38,7 months (range: 0 to 201 months). The most commonly isolated microorganisms were coagulase negative Staphylococci, followed by Staphylococcus aureus. A re-reinfection occurred in 100% after debridement, in 44% (CI 95%: 22 – 69%) after one-stage revision, in 55% (CI 95%: 31 – 91%) after two-stage revision, and 0% after amputation. Regarding two-stage revision, there was a statistically significant difference in infection rates between patients treated with complete removal of the megaprosthesis and patients with at least one retained component (Fisher's exact test, p = 0.027). Conclusions. Septic failures after megaprosthesis reconstruction of a musculoskeletal tumour of the lower limb are difficult to treat and show high reinfection and re-reinfection rates. A two-stage revision with removal of all components showed the best results among limb salvage procedures for periprosthetic megaprosthesis infection

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. Materials and Methods. In total, we treated 58 patients with megaprosthesis mono-and bi-articular subdivided as follows: proximal femur, distal femur, proximal tibia and total femur. The mean follow-up of patients is about 24 months (5 yrs max, min 6 months) with clinical and serial radiographic revaluations with standard methods (X-ray in 45 days, 3–6-12-18-24 months) as well as monitoring of blood parameters of inflammation for at least 2 months. Results. Despite the follow up average is not so long, the first patients have now reached five years of monitoring and in all cases we have had encouraging clinical results with good articulation of the segments, no somato-sensory or motorial defict and acceptable functional recovery. During surgery and, even more, in the pre-operative planning much attention should be given to the evaluation of the extensor apparatus preserving it and, when necessary, reinforcing it with tendon substitutes. Discussion. Megaprosthesis in traumatic and prosthetic failures can therefore be considered, in extreme cases appropriately selected, as a solution available to the orthopedic surgeon? In oncological surgery the opportunity to regive a function, although not ad integrum, to the patient is certainly an element of great fascination for the surgeon and an opportunity for the patient. Unfortunately, the high mortality associated with this disease does not allow us to have long-term follow-up. This then creates a lack of certainty about the survival of this type of prosthesis and the medium and long-term complications that may occur. Nevertheless, the patients treated by us should be considered as a oncologic patient, not because of the disease but for the limited therapeutic options available. Conclusions. We can consider megaprosthesis as a valuable opportunity to restore functionality to patients who are, despite themselves, to deal with highly disabling diseases

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. MATERIAL AND METHOD. 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. RESULTS. We obtained good results from a clinical, laboratory and radiological point of view with restoration of the function of the affected limb. Only in 5/55 cases the infection recurred. All the Total Femur megaprosthesis implanted in a one step procedure healed without recurrence of infection. CONCLUSION. Megaprosthesis in severe septic bone loss can be considered, in extreme cases appropriately selected, as an available solution for the orthopedic surgeon. The two steps procedure gives the best results with safety and lower infection recurrence creating a membrane (Chamber Induction Technique) that can protect the prosthesis in a safe environment. We can perform a one step procedure only when all the infected segment is entirely removed. This type of complex surgery must be performed in specialized centers where knowledge and technologies are present

Aim. Rifampicin and fluoroquinolone based therapy is generally considered as first-choice targeted oral antimicrobial therapy for staphylococcal prosthetic joint infections (PJI) treated with debridement, antibiotics and implant retention (DAIR). Alternative equally effective antimicrobial strategies are urgently needed due to toxicity and drug-drug interactions that frequently occur with this strategy. Data from recent clinical studies suggests equipoise for other antimicrobial treatment regimens. The objective of the Rifampicin Combination Therapy versus Targeted Antimicrobial Monotherapy in the Oral Antimicrobial Treatment Phase of Staphylococcal Prosthetic Joint Infection (RiCOTTA)-trial is to evaluate whether monotherapy with clindamycin is non-inferior to rifampicin/fluoroquinolone combination therapy in patients with staphylococcal PJI that are treated with DAIR. Method. The RiCOTTA-trial is a multicenter, non-inferiority, open-label, randomized controlled trial evaluating clindamycin versus rifampicin/fluoroquinolone combination therapy in the oral treatment phase in patients with staphylococcal PJI managed with DAIR. The trial is performed in 16 hospitals in the Netherlands. Eligible patients are adults with staphylococcal knee or hip PJI managed by DAIR. Patients are included one to six days before antibiotic treatment is switched from intravenous to oral therapy. Patients with a contraindication for rifampicin, with a megaprosthesis or who receive intravenous antibiotics for more than three weeks after initial debridement are excluded. Primary outcome is treatment success one year after finishing antimicrobial treatment. Success is defined as the absence of: i. Infection related re-surgery, ii. New episode of antibiotic treatment for infection of the index joint after the initial treatment phase of 12 weeks, iii. Ongoing use of antibiotics for the index joint at the end of follow-up, iv. Death. The estimated treatment success of rifampicin combination therapy is 85% and the monotherapy strategy is considered not inferior when the difference in treatment success will be less than 10%. Enrolment of 158 patients per group (316 in total) is needed to confirm non-inferiority of monotherapy with a power of 80%. The trial is currently open for enrolment. The study is approved by the Medical Ethics Committee Leiden, the Hague, Delft, the Netherlands and registered under EU trial number 2022-501620-26-00 in Clinical Trial Information System. Conclusions. Currently, the RiCOTTTA study is the largest randomised clinical trial that compares targeted oral monotherapy with rifampicin combination treatment for staphylococcal PJI. Noninferiority of monotherapy would result in a change in national PJI guidelines and enable clinicians to use a more patient-tailored approach when considering antibiotics for patients during the oral treatment phase of PJI

The use of new megaprosthesis for massive bone loss is an option for the replacement of skeletal segments. There are several clinical scenarios that can be associated with this situation including severe trauma with multiple failed osteosynthesis with a non union or with a previous prosthetic replacement of a neighbouring joint; multiple revision of arthroplasty with or without infections or large resections of tumours. The aim of this work is to evaluate retrospectively both clinical and radiological outcomes and any complications in patients treated with megaprosthesis in SEPTIC BONE DEFECTS in our Hospital from February 2012 to January 2015. From February 2012 to January 2014 a total of 20 patients were treated with mono-and bi-articular megaprosthesis subdivided as follows: 4 proximal femur, 11 distal femur, 3 total femur, 1 total humerus and 1 proximal humerus. Clinical and serial radiographic evaluations were performed at 6 weeks, 3, 6, 12, 18 and 24 months. Blood parameters with CRP and ESR were monitored for at least 2 months. The mean follow-up of patients was about 24.4 months (range 5 months to 31 months). The mean age of the patients was 53 years (range 37–80years). Of the patients 20, 9 were female and 11 were male. The aetiology was: 11 septic non unions, 3 infected TKA, 4 infected THR and 2 infected tumor prostheses. We have evaluated retrospectively both clinical and radiological outcomes of 20 patients. They had large bone defects that threatened the viability of the limb. They were treated with megaprosthesis. Although the mean length of follow-up was only 24.4 months they showed encouraging clinical results, with good articulation of the segments, no somato-sensory or motor deficit and acceptable functional recovery. There were three cases of dislocation, one case with rifampicin toxicity, one case with acute prosthetic infection (case that needed debridement and one case with chronic oral antimicrobial. Megaprosthesis provides a valuable opportunity to restore functionality to patients with highly disabling diseases. The number of complications is not depreciable

Introduction:. The development of new prostheses due to large resections has offered important opportunities to orthopedic surgeons mainly in oncology. A medline research can easily underline how poor is the international experience about this cases in nonunion: 75 results for megaprosthesis just 7 works in nonunion. It is proposed the experience of our department, which deals specifically with the treatment of nonunion, in cases of repeated failures to treatment. One of the most significant problems in the treatment of relapsing nonunion is the consequent worsening of joint function. Critical bone defects, sepsis, joint fractures and unclear relapsing nonunions are the most common cases for a megaprosthesis treatment. In these cases, even if it obtains the healing of nonunion the functional result would be presumptively poor. This radiological or clinical situation drove us, in such cases, to drastic solutions following the principles of cancer cases. We implanted megaprosthesis with either techniques: 1 stage or 2 stages depending on the clinical findings. In nonunion the main decision making was the septic or aseptic status. Materials and Methods:. we treated 32 patients with megaprosthesis replacing the nearest joint to the nonunion segment or both the proximal e distal one as follows: proximal femur, distal femur, proximal tibia, and total femur. The mean follow-up of patients is 12 months (2 yrs max, min 3 months). Clinical and serial radiographic evaluations with standard methods (RX in 45 days, 3-6-12-24 months) was performed; as well as monitoring of blood parameters for 2 months. Results:. Despite the average follow-up is not high, we do not aspect main differences to oncologic survival of the device, so our expectations and main interest to our experience is faced to the functional status of these patients and clinical evaluation in septic cases. In all cases, however, we get encouraging clinical results with such prosthesis. Complications: no neurologic defect was observed. The main surgical difficulty was the chronic reducing of the range of motion of the extending mechanism of the knee, usually not involved in such a way in oncologic cases. In these cases we were forced to reinforce mainly the patellar tendon with tendon substitutes. Discussion:. mega-prosthesis in post-traumatic cases can be considered, in extreme cases, as an available solution to the orthopedic surgeon. In oncological surgery the opportunity to get back to a good function although not a “restitution ad integrum” is a success, if it is possible to eradicate the tumor. Unfortunately, the high mortality associated with this disease does not allow us to have long-term follow-up due to the big amount of cases lost at the follow up. This situation creates a lack of certainty about the survival of this type of prosthesis and the medium-and long-term complications that may occur. Nevertheless, the patients treated by us should be considered oncological patients, not because of the disease but for the limited therapeutic options available. Conclusions:. We have to consider not mega-prosthesis more like a pipe dream, but rather, as a viable opportunity

Introduction. Systemic metal ion monitoring (Co;Cr) has proven to be a useful screening tool for implant performance to detect failure at an early stage in metal-on-metal hip arthroplasty. Several clinical studies have reported elevated metal ion levels after total knee arthroplasty (TKA), with fairly high levels associated with rotating hinge knees (RHK) and megaprostheses. 1. In a knee simulator study, Kretzer. 2. , demonstrated volumetric wear and corrosion of metallic surfaces. However, prospective in vivo data are scarce, resulting in a lack of knowledge of how levels evolve over time. The goal of this study was to measure serum Co and Cr levels in several types TKA patients prospectively, evaluate the evolution in time and investigate whether elevated levels could be used as an indicator for implant failure. Patients and Methods. The study was conducted at Ghent University hospital. 130 patients undergoing knee arthroplasty were included in the study, 35 patients were lost due to logistic problems. 95 patients with 124 knee prostheses had received either a TKA (primary or revision) (69 in 55 patients), a unicompartimental knee arthroplasty (7 UKA), a RHK (revision −7 in 6 patients) or a megaprosthesis (malignant bone tumours − 28 in 27 patients) (Fig 1). The TKA, UKA and RHK groups were followed prospectively, with serum Co and Cr ions measured preoperatively, at 3,6 and 12 months postoperatively. In patients with a megaprosthesis, metal ions were measured at follow-up (cross-sectional study design). Results (Fig 2 and 3). In primary knees, we did not observe an increase in serum metal ion levels at 3, 6 or 12 months. Two patients with a hip arthroplasty had elevated preTKA Co and Cr levels. There was no difference between unilateral and bilateral knee prostheses. In the revision group, elevated pre-revision levels were found in 2 failures for implant loosening. In both cases, ion levels decreased postoperatively. In revisions with a standard TKA, there was no significant increase in metal ions compared to primary knee arthroplasty. RHK were associated with a significant increase in Co levels even at short-term (3–12 months). The megaprosthesis group had the highest metal ion levels and showed a significant increase in Co and Cr with time in patients followed prospectively. With the current data, we could not demonstrate a correlation between metal ion levels, size of the implant or length of time in situ. Discussion. In primary knee arthroplasty with a standard TKA or UKA, metal ion levels were not elevated till one year postoperatively. This suggests a different mechanism of metal ion release in comparison to metal-on-metal hip arthroplasties. In two cases of revision for implant loosening, pre-revision levels were elevated, possibly associated with component wear, and decreased after revision. With RHK, slightly elevated ion levels were found prospectively. Megaprostheses had significantly elevated Co and Cr levels, due to corrosion of large metallic surfaces and/or wear of components which were not perfectly aligned during difficult reconstruction after tumour resection. Further research is needed to assess the clinical relevance of metal ion levels in knee arthroplasty. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

Introduction. Bone loss management represents one of the most challenging issues for the orthopaedic surgeon. In most cases, stems, structural allograft, TMcones, and sleeves are adequate to allow optimal implant stability and durable fixation. In selected cases of wide metadiaphyseal bone defects, these devices do not provide proper intraoperative stability. In such scenarios, further steps are needed and include complex modular reconstruction, substitution with megaprosthesis (exposing patients at high risk of early failure) or joint arthrodesis that can yield unacceptable results. The aim of this paper is to present early results obtained with a new custom-made implant for complex metadiaphyseal bone defects management in knee revision surgery. By means of case presentations the authors would highlight the possibilities and technical notes of this novel device in complex knee revision surgery. Methods. Since2015, 8 custom-made porous titanium devices were implanted for massive bone defect management in 6 knee arthroplasty revision procedures. Five patients were staged revision for periprosthetic joint infection (PJI) and one patient underwent a staged revision for post-traumatic septic arthritis. Main demographic and surgical data were collected. Clinical (Range of Movement [ROM], Knee Society Score [KSS] and Oxford Knee Score [OKS]), radiological findings and complications were recorded at different time points and statistically evaluated. Mean follow up was 19.5 ± 9.6months. Results. The study group included 4 males and 2 females with a mean age of 63.7 ± 5.5 years and a mean Body Mass Index of 29.3 ± 4.1. Globally, the mean number of previous surgeries was 4.8 ± 2.7. The custom made device was combined with a hinged prosthesis in 5 cases and with a constrained condylar implant in 1 patient. Hybrid fixation was used in all cases. The mean KSS and OKS of the entire population improved significantly from 35.3 ±6.5 and 19.2 ±3.5 preoperatively to 85.8 ±4.0 and 39.3 ±3.1 at the time of last follow-up evaluation (p<0.01). The range of motion improved from 46.7 ±9.8 of mean preoperative flexion and 7.8 ±6.8 of mean preoperative flexion contracture to 93.3 ±10.3 and 1.2 ±2.9 respectively (p<0.01). Radiological analysis showed no migration or implant loosening. No intraoperative or postoperative complication was recorded. One patient required a prolonged antibiotic therapy for positive culture samples of sonication of the retrieved spacer. No implant mismatch between the preoperative planning and the final implant was reported. Conclusion. The presented custom-made implant showed promising early clinical and radiological results. In extremely selected cases, this new device can be considered a safe and effective surgical step between “off the shelf” reconstruction implants and knee substitution with a tumor megaprosthesis. Accurate surgical planning and intraoperative management of soft tissues and residual bone stock are of paramount importance

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. Objectives. The aim of this study is to perform a review of the literature about Silver coated implants in Orthopaedics and Trauma and to analyze our cases treated with this implants in order to measure their efficacy and the ion dispersion in urine and blood. Methods. We performed a literature review using the universally validated search engines in the biomedical field: PubMed / Medline, Google Scholar, Scopus, EMBASE. The keywords used were: “Silver”, “Silver coating”, “Silver surface”, “were crossed with “Prosthesis”, “Megaprosthesis”, “Infection”, “Sepsis”, “Revision”. We also analized all our patients treated with Silver coated implants measuring Silver dose in blood and urine before implantation, 1 day after implantation and then after 15 days, 3,6,12,24,36 months. Results. The search led to 468 items, of these were considered only article in English with full text available. We found 1 in vitro study, 1 animal study and 2 human studies. The animal study showed a reduction in periprosthetic infection from 47% to 7%, 1 human study in Oncology application of megaprosthesis showed a reduction of septic complications from 17,6% to 5,9%. Te other human study demonstrated that Silver surface implants don't have toxicity cause the blood level of silver Ions were only 56,4 parts per billion. The analysis of our casuistry is giving good results with low level of Silver in the blood and urine, lower concentrations are observed in patients treated with the 2 steps-CIT technique. Conclusions. The use of silver-coated prosthesis can reduce the infection rate in the medium-long term with no toxicity for the patients. Further studies with longer term follow-up periods and larger numbers of patients are warranted in order to confirm these encouraging results most of all in the patients treated with the 2 steps procedure in order to better understand the role of the membrane and of the Chamber Induction Technique in Silver ions dispersions

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. Objectives. The purpose of this study is to evaluate retrospectively the outcome after the implantation of megaprosthesis of the lower limbs in prosthetic infected revision. Methods. We have retrospectively evaluated all the patients we have treated with implantation of megaprosthesis in septic prosthesis revision. Between January 2008 and January 2014 we have treated 25 patients: 18 cases of hip revision and 7 cases of knee revision. All patients were treated with a two steps procedure. Results. We obtained good results from a clinical, laboratory and radiological point of view with restoration of the function of the affected limb in 22/25 cases. In 3/25 cases the infection recurred and an additional surgery was necessary. Conclusions. Megaprosthesis in large septic revision can be considered, in extreme cases appropriately selected, an available solution for the orthopedic surgeon able to restore function to the patient. The two steps procedure gives the best results with safety and lower infection recurrence creating a membrane (Chamber Induction Technique) that can protect the prosthesis in a safe environment. This type of complex surgery must be performed in specialized centers where knowledge and technologies are present

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. Objectives. The purpose of this study is to evaluate retrospectively the early outcome after the implantation of this megaprosthesis of the lower leg in infected post-traumatic bone defects and septic peri-device bone loss. We registered all the complications and infection recurrence. Methods. Between January 2013 today we have developed this system following the chamber induction technique (C.I.T.). We perform a 2 steps procedure: 1° step: resection, debridement, devices removal and bi-antibiotic spacer implantation; 2° step: spacer removal and megaprosthesis implantation. Results. Our first 10 patients with lower leg septic critical size bone defect were post-traumatic, 3 have ended the C.I.T. procedure with good clinical result and return to function. Conclusions. The background experience in orthopaedic oncology, has allowed to develop megaimplants to break the vicious cycle of osteomyelitis and restore an optimal performance of the affected segment. We can perform a one step procedure only when all the infected segment is entirely removed, in other partial resections is better to follow a two steps procedure. In the development of this project will be possible to connect to a Megasystem C; this system will then be able to replace from the hip to the foot in the most complex cases. We also concluded that this type of complex surgery must be performed in specialized centers where knowledge and technologies are present

Peri-prosthetic fractures above a TKA are becoming increasingly more common, and typically occur at the junction of the anterior flange of the femoral component and the osteopenic metaphyseal distal femur. In the vast majority of cases the TKA is well fixed and has been functioning well prior to fracture. For loose components, revision is typically indicated. Typically a megaprosthesis is required. Well-fixed components, internal fixation is preferred. Fixation options include retrograde nailing or lateral plating. Nails are typically considered in arthroplasties that allow intercondylar access (“open box PS” or CR implants) and have sufficient length of the distal fragment to allow multiple locking screws to be used. This situation is rare, as most distal fragments are quite short. If a nail is chosen, use of a long nail is preferred, since it allows the additional fixation and alignment that diaphyseal fill affords. Short nails should be discouraged since they can “toggle” in the meta-diaphysis and do not engage the diaphysis to improve coronal alignment. Plates can be used with any implant type and any length of distal fragment. The challenge with either fixation strategy is obtaining stable fixation of the distal fragment while maintaining length, alignment, and rotation. Fixation opportunities in the distal fragment can be limited due to obstacles caused by femoral component lugs, boxes, stems, cement mantles, and areas of stress shielding or osteolysis. Modern lateral locked plates can be inserted in a biologically friendly submuscular extra-periosteal fashion. More recent developments with polyaxial locked screws (that allow angulation prior to end-point locking) may offer even more versatility when distal fragment fixation is challenging. The goal of fixation is to obtain as many long locked screws in the distal fragment as possible. High union rates have been reported with modern locked plating techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension

Peri-prosthetic fractures above a total knee arthroplasty (TKA) are becoming increasingly more common, and typically occur at the junction of the anterior flange of the femoral component and the osteopenic metaphyseal distal femur. In the vast majority of cases the TKA is well-fixed and has been functioning well prior to fracture. For loose components, revision is typically indicated. Typically a megaprosthesis is required. For well-fixed components, internal fixation is preferred. Fixation options include retrograde nailing or lateral plating. Nails are typically considered in arthroplasties that allow intercondylar access (“open box PS” or CR implants) and have sufficient length of the distal fragment to allow multiple locking screws to be used. This situation is rare, as most distal fragments are quite short. If a nail is chosen, use of a long nail is preferred, since it allows the additional fixation and alignment that diaphyseal fill affords. Short nails should be discouraged since they can “toggle” in the meta-diaphysis and do not engage the diaphysis to improve coronal alignment. Plates can be used with any implant type and any length of distal fragment. The challenge with either fixation strategy is obtaining stable fixation of the distal fragment while maintaining length, alignment, and rotation. Fixation opportunities in the distal fragment can be limited due to obstacles caused by femoral component lugs, boxes, stems, cement mantles, and areas of stress shielding or osteolysis. Modern lateral locked plates can be inserted in a biologically friendly submuscular extra-periosteal fashion. More recent developments with polyaxial locked screws (that allow angulation prior to end-point locking) may offer even more versatility when distal fragment fixation is challenging. The goal of fixation is to obtain as many long locked screws in the distal fragment as possible. High union rates have been reported with modern locked plating techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension

Despite our best efforts, occasionally, certain patients will have multiply operated, failed reconstructions after TKA. There are situations where further attempts at arthroplasty are unwise, for example, chronic infections with multiple failed staged reconstructions. A careful pre-operative evaluation of the patient is critical to guide decision-making. An assessment of medical comorbidity, functional demands, and expectations is important. Regarding the extremity, the severity of bone loss, soft tissue defects, ligamentous competency, and neurovascular status is important. The next step is to determine whether the knee is infected. The details of such a workup are covered in other lectures, however, the author prefers to aspirate all such knees and obtain C reactive protein and sedimentation rates. For equivocal cases, PCR may be helpful. If no infection is present, complex reconstruction is considered. Segmental megaprosthesis and hinged prostheses may be helpful. Often, soft tissue reconstruction with an extensor mechanism allograft or muscle flap is required. Obviously, these are massive undertakings and should be done by experienced surgeons. If a prosthesis is not a good option, other options include definitive resection, knee arthrodesis, or above knee amputation. A careful discussion with the patient about the pros and cons is necessary to allow them to partner with the surgeon in the decision-making. Definitive resections are reserved for minimal to non-ambulators with significant comorbidity that do not desire an AKA. AKA is often the best option, however, it should be noted that the majority of these patients will never ambulate with a prosthesis due to the energy requirements necessary to do so. High complication rates and reoperation rates have been reported with AKA after TKA. Functional outcome studies have generally shown better function with arthrodesis than with AKA. Arthrodesis can be effective and can be accomplished with several methods. If active infection is present, an external fixator is typically chosen. If no infection is present then plating or long intramedullary nailing is considered. Plating requires healthy anterior soft tissues due to the bulk associated with double plating techniques. The highest union rates have been reported with long nails. The author therefore prefers to use long nails after eradicating infection with a staged procedure (interval spacer) rather than to use an external fixator. Union rates are higher with nails, but the risk of re-infection is slightly higher as well. Careful attention to detail is necessary to minimise complications

Despite our best efforts, occasionally, certain patients will have multiply operated, failed reconstructions after TKA. There are situations where further attempts at arthroplasty are unwise, for example, chronic infections with multiple failed staged reconstructions. A careful preoperative evaluation of the patient is critical to guide decision-making. An assessment of medical comorbidity, functional demands, and expectations is important. Regarding the extremity, the severity of bone loss, soft tissue defects, ligamentous competency, and neurovascular status is important. The next step is to determine whether the knee is infected. The details of such a workup are covered in other lectures, however, the author prefers to aspirate all such knees and obtain C reactive protein and Sedimentation Rates. For equivocal cases, PCR may be helpful. If no infection is present, complex reconstruction is considered. Segmental megaprosthesis and hinged prostheses may be helpful. Often, soft tissue reconstruction with an extensor mechanism allograft or muscle flap is required. Obviously, these are massive undertakings and should be done by experienced surgeons. If a prosthesis is not a good option, other options include definitive resection, knee arthrodesis, or above knee amputation. A careful discussion with the patient about the pros and cons is necessary to allow them to partner with the surgeon in the decision-making. Definitive resections are reserved for minimal to non-ambulators with significant co-morbidity that do not desire an AKA. AKA is often the best option, however, it should be noted that the majority of these patients will never ambulate with a prosthesis due to the energy requirements necessary to do so. High complication rates and reoperation rates have been reported with AKA after TKA. Functional outcome studies have generally shown better function with arthrodesis than with AKA. Arthrodesis can be effective and can be accomplished with several methods. If active infection is present, and external fixator is typically chosen. If no infection is present then plating or long intramedullary nailing is considered. Plating requires healthy anterior soft tissues due the bulk associated with double plating techniques. The highest union rates have been reported with long nails. The author therefore prefers to use long nails after eradicating infection with a staged procedure (interval spacer) rather than to use an external fixator. Union rates are higher with nails, but the risk of re-infection is slightly higher as well. Careful attention to detail is necessary to minimise complications

Purpose. Durable fixation may be difficult to achieve when significant bone loss is present, as it occurs in pelvic sarcoma resection and revision surgery of tumor implants. Purpose of this study was to review clinical results of primary and revision surgery of the pelvis and lower extremity in the setting of severe bone loss following limb salvage procedures for bone sarcoma using modular porous tantalum implants. Method. Retrospective study of 15 patients (nine females, six males) undergoing primary or revision pelvic reconstruction (five patients) or revision surgery of a tumor implant of the hip (five patients), knee (four patients), and ankle (one patient) using porous tantalum implants was undertaken. Reason for the tumor implant was resection of bone sarcoma in 13 cases and tumor-like massive bone loss in the remaining two cases. Cause for revision was aseptic failure (nine patients) or deep infection (six patients); average age at the time of surgery was 31 years (16–61 yrs). Revision was managed in a staged fashion in all the six infected cases. All patients presented severe combined segmental and cavitary bone defects. Bone loss was managed in all patients using porous tantalum implants as augmentation of residual bone stock and associated with a megaprosthesis in eight cases (five proximal femur, two distal femur, one proximal tibia). Average follow-up was 4.5 years for hip/knee implants and 2.5 yrs for pelvic reconstructions (range 1–6.8 yrs). Minimum follow-up of two years was available in 11 cases. Results. Infection recurred in one of the six cases managed for infection, requiring further treatment but allowing retention of the porous tantalum implant. All the patients showed well-fixed and functioning implants at latest follow-up. Conclusion. Porous tantalum has been very successful at early follow-up in patients with severe bone loss following primary and revision tumor-related surgery of the pelvis and lower extremity. Longer follow-up is required to appreciate long-term shortcomings