Introduction. the aim of the study is to evaluate the clinical results of the shoulder prosthesis revision procedure to reverse implant without removing the humeral stem using a modular system (Lima LTD) and determine if this procedure is beneficial for the patients. Methods. e selected only the patients where a revision to reverse (RSA) of hemiarthroplasty (Hemi) originally implanted for fracture (Group I) and revision to reverse (RSA) of anatomical total prosthesis (TSA) were performed. From 2004 to 2009 26 cases responding to these parameters were identified: 18 cases in Group I (failed hemiarthroplasty for tuberosities resorptions or rotator cuff failure) and 8 in Group II (failed TSA for rotator cuff omplication). The mean follow-up was 32 months (min 18–max 76) and the mean age was 72 (min 65–max 80). Clinical assessment was performed with preoperative and postoperative Constant score rating scale (CS) and range of motion evaluation (ROM). Radiological assessment was performer by AP and Axial X-ray views. Operative time was calculated. Results. overall pre-op CS was 24 (min 18–max 30), post-op CS was 47,8 (min 35–max 60). In Group I the mean improvement of CS was 25,3; in Group II was 17. All patients had a clinical improvement of the range of motion. X-Rays study did not show radiolucent lines related to implant mobilization. No major complications were observed in all the cases. Discussion and Conclusion. Revision surgery for failed Hemi or TSA is commonly related to a relatively increase of complication and/or poorer out come if compared to a primary RSA implant. Our study results demonstrate that using a full modular system from the first implant allows to skip the humeral stem removal/reimplant step in case of conversion of a shoulder prosthesis to a reverse with good clinical result, no radiological signs of mobilization and non major complication probably related to a shorter and less aggressive operative time and procedure

Introduction. Numerous fixation modalities can be used for various indications, including deformity correction, trauma, infection, and non-union. The Modular Rail System (MRS) is a well-tolerated apparatus that is a viable option for patients who do not want a circular frame or for whom internal fixation is not appropriate due to poor soft tissues/co-morbidities. This case series evaluates the outcomes of the use of the MRS in our centre. Materials and Methods. Cases were identified from a prospectively gathered database. Data were collected including indication for treatment, frame duration, complications and treatment outcome. Eighteen eligible cases were identified (mean age 26, range 8–71). The MRS was sited in the femur in 14 cases, the tibia in three and the fibula in one. In nine cases, a circular frame was sited on the tibia below a femoral MRS. Frames were removed at an average of 20 weeks (range 7–31). Results. Eight complications occurred in six patients including fracture following removal (2), premature union (2), deep infection (1), scar complications (1), pin exchange (1) and non-union (1). 17/18 patients achieved their treatment goal and a satisfactory clinical outcome. Conclusions. We have demonstrated the use of the MRS in both trauma and elective practice and have found it to be well tolerated in our cohort of patients, particularly the paediatric and elderly populations. This case series demonstrates that, with the correct patient selection, the MRS is a versatile adjunct for use in limb reconstruction cases

We evaluated intermediate-term results of primary cementless Omniflex prostheses.

Forty-nine patients (57 hips) with a mean age of 44 years were observed for an average of 8.6 years.

These results were inferior to those using other recent cementless total hip systems. The increasing prevalence of loosening and osteolysis with time are problems related to this Omniflex femoral component. Although the implant design is unique, the authors no longer use this system.

Aim. To evaluate outcome and complications of knee arthrodesis with a modular prosthetic system (MUTARS(r) Implantcast), as primary and revision implants in musculoskeletal oncology. Method. Between 1975 and 2009, 24 prostheses were used for knee arthrodesis. Nineteen in oncologic cases: 6 osteosarcomas, chondrosarcoma, synovial sarcoma and metastatic carcinoma 3 each, 2 pigmented villonodular synovitis (PVNS), malignant fibrous hystiocitoma and giant cell tumour 1 each. Patients were grouped into: A) primary implants, B) revision implants. Group A included 9 patients: 8 arthrodeses after extra-articular resection with major soft tissue removal, 1 after primary resection following multiple excisions of locally recurrent PVNS. Group B included 15 patients: 12 arthrodeses for infection (5 infected TKAs, 7 infected megaprostheses), 2 for failures of temporary arthodesis with Kuntscher nail and cement, 1 for recurrent chondrosarcoma in previous arthrodesis. Results. Oncologic outcome ata mean follow-up of 6 years (ranging 1 to 26), showed 13 NED (68.4%), 2 NED after treatment of relapse (10.5%), 1 alive with metastases (5.3%), 2 dead with disease (10.5%) and one dead of other disease (5.3%). Complications causing failure were observed in 12 patients (50%): 11 infections at mean of 14 months (6 in arthrodeses as revision for previous infections, 5 in group A), 1 femoral stem breakage at 4.8 years (in group B). Treatment of infections was: amputation in 6, “one stage” in 1, “two stage” with new arthrodesis in 4 (1 subsequently amputated for recurrent infection). The breakage was revised, had further traumatic breakage at 2 years and a second revision. Conclusion. Arthrodesis with modular prosthetic system is indicated after major extra-articular resection or in revisions of severely failed previous reconstructions. High infection rate should be prevented with good soft tissue coverage, by flaps if needed

Introduction and Aims: Difficult primary and revision total knee arthroplasty (TKA) with constrained knee systems is becoming more common. Modular systems are critical to success. A review of 457 consecutive cases with a single knee system for difficult primary and revision TKA provides an algorithm for good results. Method: Between July 1992 and December 2000, 457 consecutive TKA were performed at a single institution using a posterior-stabilised constrained (PSC) system. Ninety-seven cases were primary with ligamentous instability and 360 were revision cases with bone loss and instability. Sixty-two patients died during follow-up, seven were lost to follow-up. Results: Follow-up averaged 2.5 years. Pre-operative Knee Society (KSS) and Hospital for Special Surgery (HSS) scores averaged 47.3 and 60.0 respectively, and improved to 79.0 and 75.0 (p< 0.001). Range of motion improved significantly (p< 0.001). Incidence of manipulation was 9.4 percent. Infection necessitated debridement in 4.6 percent of cases. Extensor mechanism complications occurred in 2.2 percent. Excision of the patellar component without reinsertion was highest risk. There was a 2.2 percent aseptic loosening rate and 3.0 percent failure for instability. Conclusion: The authors describe an algorithm for long-term success using a PSC modular knee system based upon critical review of radiographic and clinical outcomes. Methods for achieving stability and fixation affect results. Appropriate augmentation for femoral and tibial deficits re-establishes the joint line and provides excellent range of motion. A step-wise approach to the patella provides durable results. Predictors of success including alignment, the joint line, managing bone loss, fixation, and extensor mechanism are reviewed

Introduction: The double threaded Cone Modular Hip Replacement System has been used in 114 patients as a primary prosthesis in over three years. No patient has been lost to follow up and all patients have been assessed postoperatively for the Harris Hip Score, Pain Score, Dexa analysis as well as plain X-rays. Method: 114 patients requiring primary hip replacement were entered into a prospective clinical trial over a three year period. The Harris Hip Score, Pain Score and Dexa analysis (Luna 2000 program) and X-rays were assessed at six weeks, three months, six months, twelve months, two years and three years and results were compared with the preoperative figures. Length of hospital stay, discharge details (home or rehabilitation unit) and physiotherapy assessment of time to independent stair climbing was prospectively assessed. Results: The Dexa analysis indicates a loss of bone at two years at Gruen’s zones one and seven of 25% and at zones two and six of approximately 20% with no increase or loss of bone in zones three, four and five. The Harris Hip Scores and Pain Scores show a significant improvement comparing preoperative with postoperative results in this series. One patient required revision of the femoral neck component for recurrent dislocation and three patients have significant rotational thigh pain due to varus implantation of the stem (the pilot has since been shortened and the diameter reduced by 1mm). Conclusion: The double threaded cone shaped modular hip prosthesis stem allows immediate full weight bearing postoperatively. No prosthesis has loosened or subsided and the locking mechanism has been shown to gain immediate and long term fixation as a primary prosthesis stem. Clinical assessment, X-rays and Dexa analysis indicate satisfactory results with good incorporation of the prosthesis by the bone

Purpose: To report a series of unexpected femoral neck failures in a series total hip replacement surgeries using a modular femoral component.

Method: A series of 443 hip replacement patients received modular necks as part of a non cemented hip replacement with ceramic articulations at the acetabulum and femoral head interface. The first implant of the device was on June 8, 2004 and the last on June 12, 2009. Ninety-one of those patients were enrolled in a RSA study of component stability within the proximal femur.

Results: The index fracture of a femoral neck occurred on March 8, 2009 when the patient (28 months post hip replacement) reported a fall. Subsequently five patients have had a fracture of the modular neck. There were five fractures within the RSA study group and one within the non study group (all occurred 17 months to 30 months post op). All fractures were long necks (10.5 mm). There was no difference in femoral component micromotion as measured with RSA between the fractured group and the unrevised group.

Conclusion: Initial non-destructive testing of one retrieval revealed fatigue failure of the femoral neck. An independent study of all relevant data was implemented which included destructive testing of the implants and clinical data with respect to patient activity. We report the outcome of all those investigations.

From 1992 on 2008, 615/515 patients underwent primary or revisional endoprosthetic replacement of major joints. In 51 patients (31 men & 20 women) modular system MUTARS (Implantcast, Germany) has been used. The median age was 23.3 years (15 to 52 years). MUTARS modular endoprosthesis has been used in 10 patients with deep infection of endoprosthetic bed as a revisional endoprosthetic replacement: 1 Total endoprosthetic replacement of femur, 5 Total knee joint replacement (2 for distal femoral defect and 3 for proximal tibial defect). In 3(27%) patients, we used newly patented silver ion coated MUTARS either after two stage treatment for infection of endoprosthetic bed or as a prophylaxis of endoprosthetic infection. In 1 patient (23 yrs), with 12cm limb length shortening, we used extensible MUTARS as a revisional endoprosthetic replacement. The following complications we observed: Instability of endoprosthesis – 3/51 (5.9%), deep endoprosthetic bed infection – 4/51 (7.8%). In comparison group, when using custom-made endoprosthesis, the frequency of infectious complications have made 60/574 (10.5 %), and instability of implants was observed in 79/574 (13.8 %) cases. Transition of using modular systems for primary and revisional endoprosthesis allows to reduce the level of instability from 13.8 % to 5.9 %. The quantity of infectious complications is also not great as in comparison with control group. For revisional endoprosthetic replacement, we think, the given modular system is optimal, for correcting limb length deficiency and restoration of basic function at patients. Use of silver ion coated modular implants is a promising method for treating deep endoprosthetic bed infection

Aims: To investigate adequacy of temporary ex-fix in grade III open fractures of the tibia, prior to definitive treatment by Flap & Frame at 2 UK trauma centres. Methods: Between 2000 and 2006 all open fractures of the tibia treated by the Ilizarov Method at our two institutions were entered onto the Flap & Frame database. The database was searched for all temporary external fixators placed prior to definitive Ilizarov fixation. Data collected – ex-fix type, whether revision was necessary, reasons for revision. Results:. 97 grade III open fractures in 95 patients. 64 required temporary spanning ex-fix: 23 applied at trauma centre/41 at DGH. 14/64 ex-fixes required revision (prior to definitive Ilizarov): poor plastics access(6)/instability(2)/both(6). All 14 revised had been applied in a DGH, i.e. 14/41 DGH ex-fix needed revision (34%). Ex fixes revised after application at trauma centre vs. DGH = 0/23 vs. 14/41, p< 0.01 ×2. Revision of Hoffman hybrid vs. monolateral ex fix = 4/4 vs. 10/60 p< 0.001 ×2. Non modular system (Orthofix) vs. modular systems (Hoffman II/AO) = 7/17 vs. 0/39 p< 0.001. Discussion: Recently Naique and Pearse showed a revision rate of skeletal fixation of 48% in grade IIIb open fractures referred to their tertiary centre. In our series 34% of temporary external fixators needed revision. Modular systems such as Hoffman II and AO required no revision, irrespective of whether they were applied at trauma centre or DGH. All Hoffman hybrids needed revision, due to both instability and plastics access. Significantly more non modular (Orthofix) ex-fixes required revision compared to modular (Hoffmann II/AO), due to poor plastics access. Conclusion: We recommend modular external fixation systems such as Hoffman II or AO if problems of temporary external fixation of open tibial fractures are to be avoided. Hybrid temporary external fixation should be abandoned as temporary fixation in such an injury

Introduction: To investigate adequacy of temporary ex-fix in grade III open fractures of the tibia, prior to definitive treatment by Flap & Frame at 2 UK trauma centres. Methods: From 2000 – 2006 all open fractures of the tibia treated by the Ilizarov Method at our two institutions were entered onto the Flap & Frame database. The database was searched for all temporary external fixators placed prior to definitive Ilizarov fixation. Data collected - ex-fix type, whether revision necessary, reasons for revision. Results:. - 97 grade III open fractures in 95 patients. - 64 required temporary spanning ex-fix:. - 23 applied at trauma centre / 41 at DGH. - 14/64 ex-fixes required revision (prior to definitive Ilizarov):. - poor plastics access (6) / instability (2) /both (6). - All 14 revised were applied in a DGH, i.e. 14/41 DGH ex-fix needed revision (34%). - Ex fixes revised after application at trauma centre vs. DGH = 0/23 vs. 14/41, p< 0.01 X. 2. - Revision of Hoffman hybrid vs. monolateral ex fix = 4/4 vs. 10/60 p< 0.001 X. 2. - Non modular system (Orthofix) vs. modular systems (Hoffman II / AO) = 7/17 vs. 0/39 (p< 0.001). Discussion: Naique and Pearse described a revision rate of skeletal fixation of 48% in grade IIIb open fractures referred to their tertiary centre. In our series 34% of temporary external fixators needed revision. Modular systems (Hoffman II and AO) required no revision, irrespective of application at a trauma centre or DGH. All Hoffman hybrids needed revision, due to instability and plastics access. Significantly more non modular (Orthofix) ex-fixes required revision compared to modular, for poor plastics access. We recommend modular external fixator application (Hoffman II or AO) to avoid problems with temporary external fixation of open tibial fractures. Hybrid temporary external fixation should be abandoned in such injuries

Corrosion in modular taper connections of total joint replacement has become a hot topic in the orthopaedic community and failures of modular systems have been reported. The objective of the present study was to determine in vivo titanium ion levels following cementless total hip arthroplasty (THA) using a modular neck system. A consecutive series of 173 patients who underwent cementless modular neck THA and a ceramic on polyethylene bearing was evaluated retrospectively. According to a standardized protocol, titanium ion measurements were performed on 67 patients using high-resolution inductively coupled plasma-mass spectrometry. Ion levels were compared to a control group comprising patients with non-modular titanium implants and to individuals without implants. Although there was a higher range, modular-neck THA (unilateral THA: 3.0 μg/L (0.8–21.0); bilateral THA: 6.0 μg/L (2.0–20.0)) did not result in significant elevated titanium ion levels compared to non-modular THA (unilateral THA: 2.7 μg/L (1.1–7.0), p = 0.821; bilateral THA: 6.2 μg/L, (2.3–8.0), p = 0.638). In the modular-neck THA group, patients with bilateral implants had significantly higher titanium ion levels than patients with an unilateral implant (p < 0.001). Compared to healthy controls (0.9 μg/L (0.1–4.5)), both modular THA (unilateral: p = 0.029; bilateral p = 0.003) and non-modular THA (unilateral: p < 0.001; bilateral: p < 0.001) showed elevated titanium ion levels. The data suggest that the present modular stem system does not result in elevated systemic titanium ion levels in the medium term when compared to non-modular stems. However, more outliner were seen in modular-neck THA. Further longitudinal studies are needed to evaluate the use of systemic titanium ion levels as an objective diagnostic tool to identify THA failure and to monitor patients following revision surgery

Periprosthetic fractures involving the femoral meta/diaphysis can be treated in various fashions. The overall incidence of those fractures after primary total knee arthroplasties (TKA) ranges from 0.3 to 2.5%, however, can increase above 30% in revision TKA, especially in older patients with poorer bone quality. Various classifications suggest treatment algorithms. However, they are not followed consequently. Revision arthroplasty becomes always necessary if the implant becomes loose. Next, it should be considered in case of an unhappy TKA prior to the fracture rather than going for an osteosynthesis. Coverage of the associated segmental bone loss in combination with proximal fixation, can be achieved in either cemented or non-cemented techniques, with or without the combination of osteosynthetic fracture stabilization. Severe destruction of the metaphyseal bone, often does not allow adequate implant fixation for the revision implant and often does not allow proper anatomic alignment. In addition the destruction might include loss of integrity of the collaterals. Consequently standard or even revision implants might not be appropriate. Although first reports about partial distal femoral replacement are available since the 1960´s, larger case series or technical reports are rare within the literature and limited to some specialised centers. Most series are reported by oncologic centers, with necessary larger osseous resections of the distal femur. The implantation of any mega prosthesis system requires meticulous planning, especially to calculate the appropriate leg length of the implant and resulting leg length. After implant and maybe cement removal, non-structural bone might be resected. Trial insertion is important due to the variation of overall muscle tension and recreation of the former joint line. So far very few companies offer yet such a complete, modular system which might also be expanded to a total femur solution. Furthermore it should allow the implantation of either a cemented or uncemented diaphyseal fixation. In general, the fracture should be well bridged with a longer stem in place. At least 3 cm to 5 cm of intact diaphysis away to the fracture site is required for stable fixation for both cemented and cementless stems. Application of allograft struts and cables maximises the biomechanical integrity of the fracture zone to promote fracture repair and implant fixation. Modular bridging systems do allow centimeter wise adaption distally, to the knee joint. Consequently in modern systems fully hinged or rotational hinge knee systems can be coupled, and adjusted accordingly to the patellar tracking and joint line. Fixation of the tibial component can be achieved in uncemented and cemented techniques. We still prefer the latter. Although a reliable and relatively quick technique, frequent complications for all mega systems have been described. These usually include infections, rotational alignment and loosening of the femoral fixation or subsequent proximal femoral fractures. Infections usually can be related to large soft tissue compromise or extensive exposure or longer procedure times. Thus implantation of such reconstruction systems should be reserved to specialised centers, with adequate facilities experience, in order to minimise complications rates and optimise patients function postoperative

Modern hip implants feature a modular design, whereby the individual components of the implant are assembled during the surgery. Increased reported failure rates associated with the utilization of modular junctions have raised many clinical concerns about the increased release of metal ions/debris leading to adverse local tissue reactions. Implant materials are subject to a myriad of mechanical motion and forces, and varying electrochemical conditions and pH changes from the surrounding environment. To date, no studies have attempted to model the collected data in order to predict the performance of the materials so that precautions can be taken before the problem reaches the critical stage. This study reports the effects of pH variation, displacement variation, and load variation on the mechanical and corrosion behavior of the hip implant modular junction system, tested with a custom-built fretting-corrosion apparatus. The main objective of this study is to combine the complete data set of the in-vitro experiments to create fretting-corrosion wear maps that can predict the dangerous domains of the hip implant modular system. For each test, the flat portions of two CoCrMo pins were loaded perpendicularly against a Ti6Al4V Rod (Ti alloy) in a Flat-on-flat configuration in a simulated synovial fluid in order to simulate the modular hip implant system. A schematic diagram of contact conditions is presented in Figure 1. A sinusoidal displacement was applied onto the rod, which articulated against the CoCrMo alloy pins, at a frequency of 1Hz. The experiential data from the fretting-corrosion tests has been used to create fretting-corrosion maps. The variables incorporated into the maps include: total mass loss, electrochemical destabilization, pH variation, load variation, displacement variation, and visual examination of the wear features of the contact zone. Total mass loss has been estimated via measurement of the simulator fluid by ICP-MS technique. Electrochemical destabilization was evaluated by a single parameter (V. Drop. ). The electrochemical destabilization of the tribosystem was evaluated by measuring the drop in potential, V. Drop. (V vs. SCE), resultant from the initiation of the fretting phase. The V. Drop. refers to the initial cathodic drop in potential in response to the initial onset of fretting motion. The data from the in vitro fretting-corrosion experiments has been combined to create four fretting-corrosion maps (Figures 2A–3D). Partial slip wear features and mechanical behavior was observed at 25µm displacement. 25–150µm displacement amplitudes showed gross slip behavior. Anything larger than 150µm displayed wear features that were indistinguishable from sliding wear. In general, total mass loss and V. Drop. increased with increasing displacement. Samples that were tested at pH 6.0 or higher showed signs of material transfer and higher V. Drop. Finally, there was a general decrease in V. Drop. with increased applied load and pH. In general, the wears maps were able to offer some predictive validity, however, there were some discrepancies between visual observations and the observed damage parameters. It is possible that other parameters could offer better correlation. Future studies will be conducted to measure other parameters. For figures/tables, please contact authors directly.

INTRODUCTION. Managing severe periacetabular bone loss during revision total hip arthroplasty (THA) is a challenging task. Multiple treatment options have been described. Delta Revision Trabecular Titanium™ (TT) cup is manufactured by Electron Beam Melting (EBM) technology that allows modulating cellular solid structures with an highly porous structure were conceived to rich the goals of high bone ingrowth and physiological load transfer. The caudal hook and fins ensure additional stability and the modular system allows the surgeon to treat bone defects in the most complex revisions. Entirely modular, the system can meet all intra-operative needs thanks to a customized implant construction. The aim of this prospective study is to evaluate the short to mid-term clinical and radiographic outcomes of this acetabular revision cups. MATERIALS AND METHODS. We prospectively assessed clinical and radiographic results of 31 cases of acetabular revisions that were performed from June 2007 and March 2012 by Delta TT Lima Revision system. The mean age of patients was 69.5 years (range 29–90). The causes of revision were aseptic loosening in 22 cases (71.0%), periprosthetic acetabular fractures in 4 cases (13.0%), multiple dislocation of the primary implant in 3 cases (9.6%) and outcome of infection in 2 cases (6.4%). Stem revision was performed in 11 cases (35,4%). In 24 cases bone impaction grafting was used to fill cavitary defects (Paprosky 2B-3A); in 7 cases TT augments were used with the same aim. The average follow-up was 32 months (range 12–69). RESULTS AND CONCLUSIONS. No major complications were observed. The mean HHS significantly increased from 39.9 (range 17–60) preoperatively to 86.5 (range 65–100) at the last follow-up examination. The implanted cups were radiographically stable at the last follow-up visit without radiolucent lines or periprosthetic osteolysis. Trabecular Titanium showed a high capacity of osseointegration, providing excellent results in short to mid-term follow-up. The impaction grafting has demonstrated effective restoration of bone stock and no radiographic evidence bone resorption (Fig. 1). DISCUSSION. Delta Revision TT is a good solution for acetabular revision surgery even when there are cavitary and segmental bone defects. It is possible to restore muscle tension and correct anatomical impairments, while enhancing implant stability and minimising the risk of dislocation

Aims

Custom-made partial pelvis replacements (PPRs) are increasingly used in the reconstruction of large acetabular defects and have mainly been designed using a triflange approach, requiring extensive soft-tissue dissection. The monoflange design, where primary intramedullary fixation within the ilium combined with a monoflange for rotational stability, was anticipated to overcome this obstacle. The aim of this study was to evaluate the design with regard to functional outcome, complications, and acetabular reconstruction.

Aims

The proximal tibia (PT) is the anatomical site most frequently affected by primary bone tumours after the distal femur. Reconstruction of the PT remains challenging because of the poor soft-tissue cover and the need to reconstruct the extensor mechanism. Reconstructive techniques include implantation of massive endoprosthesis (megaprosthesis), osteoarticular allografts (OAs), or allograft-prosthesis composites (APCs).

Aims

The objectives of this study were to investigate the patient characteristics and mortality of Vancouver type B periprosthetic femoral fractures (PFF) subgroups divided into two groups according to femoral component stability and to compare postoperative clinical outcomes according to treatment in Vancouver type B2 and B3 fractures.

Aims

The objective of this study was to compare simulated range of motion (ROM) for reverse total shoulder arthroplasty (rTSA) with and without adjustment for scapulothoracic orientation in a global reference system. We hypothesized that values for simulated ROM in preoperative planning software with and without adjustment for scapulothoracic orientation would be significantly different.

Aim. Prosthetic joint infections (PJI) after failed knee arthroplasty, especially in complicated courses with persisting or recurrent infections, may result in a considerable destruction of bone substance, the extensor apparatus and the surrounding soft tissue. In these cases reconstruction of a proper knee function may be impossible and the only solutions are: knee arthrodesis or above-the-knee amputation (AKA). However, both methods are associated with considerable functional deficits and high complication rates. The primary aim of the current study is to analyse the clinical course, outcome and complications in patients with knee arthrodesis and AKA after PJI and to compare these two methods in terms of the analysed parameters. Method. Patients treated with a knee arthrodesis or AKA after PJI in an 11-year time period were included in this study. Demographic data, comorbidities, infecting characteristics and operative procedures were recorded. Patients were seen in regular intervals and underwent physical and radiographic examination. Major complications such as: re-infection, implant-failure, revision surgeries or stump healing disorders were recorded. Functional outcome with use of the Lower-Extremity-Functional-Score was assessed and the patients reported general health status (SF-12-questionnaire) was recorded. Results. In total 87 patients with a knee arthrodesis and 32 patients with an AKA after PJI were included. Knee arthrodesis was performed in 81 patients with a modular system and in six cases with bone fusion. Re-arthrodesis had to be performed in 21 cases. Survival rate of knee arthrodesis was 86% after one year, 71% after five and 61% after ten years. Major complications such as recurrence of infection (n=16) implant loosening (n=12), implant failure (n=3) or per-implant fracture (n=5) occurred in 30% of the patients. In seven patients an amputation after failed arthrodesis had to be performed. In patients with AKA after PJI a similar complication rate of 34% (p=0.64) was seen. Recurrence of infection was diagnosed in nine patients and a re-amputation had to be performed in four cases. The final functional examination was assessed after a mean interval of 48 month and revealed comparably in both cohorts a comparable limitation of functionality (p=0.181) and a slightly worse physical quality of life after knee arthrodesis compared to patients with AKA (p=0.08). Conclusions. Knee arthrodesis or above the knee amputation after PJIshow similar functional limitations and comparably high complication rates. The patients have to be supervised by an interdisciplinary team to avoid complications and regain quality of life

The purpose of the following study was to present the general strategy for preserving the lower extremity by knee arthrodesis and to analyze the outcome of knee arthrodeses performed by a special modular system. Between 2009 and 2014 35 knee arthrodeses were performed. 23 patients were male, 12 female. The average age was 66 years (42 to 83 years). The patients underwent an average of 6 operations because of infected knee arthroplasties previous to the knee arthrodesis. The main pathogen was S. epidermidis followed by MRSA. The arthrodeses system included a non cemented femoral and tibial stem (press fit application plus two static locking screws). These were connected by a special stem to stem clamp. Immediate postoperative full weight-bearing was possible in 32 of 35 patients. We saw 4 recurrent infections (all connected to the patients, who did not show a full weight bearing after knee arthrodesis). In two cases re-revision surgery was successful and lead to a sufficient re-arthrodesis. In two cases above-knee-amputation was necessary. Peri-implant fractures were detected in 3 cases. All of them could be cured by changing the arthrodesis stem and to a longer one bridging the fracture. In one case a stem loosening was seen. This was as well addressed by the use of a longer stem. Knee arthrodesis by a modular non cemented system is a god alternative in order to preserve the weight-bearing lower extremity. The complication rate is rather high due to the fact, that this procedure presents the final alternative to do so in patients, who are in extremis in terms of a long lasting aggressive peri-arthroplasty infection the lead to massive destruction of the soft tissue around the knee and a significant loss of function