The present case report concerns a 69-year-old male patient who was admitted to the department of traumatology and orthopaedic surgery. The patient was admitted in February 2014 after he had a bicycle accident. Standardized X-rays of the affected leg showed a periprosthetic fracture of the tibia and an upper fracture of the fibula which was negligible (Felix [Mayo] classification Type IIIa, ). In the medical history of the left knee, the patient underwent primary TKA in May 2004 due to osteoarthritis. Furthermore, revision surgery was performed with the implant changed to a constrained TKA system due to an aseptic loosening in October 2013. The patient reported a satisfying functional and subjective outcome of his left knee before the accident. We saw the patient with a painful leg but without any clinical signs of compartment syndrome. Diagnostics and pre-operative planning were completed with a computed tomography scan and laboratory counts. Primary care included stabilization with a knee joint bridging external fixator and a puncture of the knee. After soft tissue conditions were improved the external fixator was removed, andthe tibial fracture was stabilized with a plate and two wire cerclages (less invasive stabilization system [LISS], 13 screw holes, Synthes GmbH, Umkirchbei Freiburg, Germany) (). Inpatient care consisted of mobilization with two crutches and a partial weight bearing (20 kg). Microbiological examination of the initial joint puncture and all samples taking during the operation was negative. The patient was discharged with unremarkable wound conditions and normal blood counts. The patient was readmitted with persistent pain and serous secretion from a necrotic area of the distal wound 3months after discharge. Radiological examination showed a delayed union of the fracture. Immobilization in a cast and local resection of the necrosis could not prevent wound worsening within 1month. Therefore, revision surgery of the wound with a deep debridement had to be performed. Due to the missing wound consolidation, soft tissue debridement was performed in two more surgeries. The first procedure was completed with an extensive cleansing, insertion of a gentamicin-impregnated sponge, and an occlusive vacuum bandage. Antibiotic therapy was accomplished with a combination of cefuroxime (3 × 1.5 g i.v., Fresenius Kabi Austria GmbH, Graz, Austria) and clindamycin (2 × 600 mg, MIP Pharma GmbH, Blieskastel, Germany). This therapy was given in accordance with the spectrum of resistance of a multi-sensitiveStaphylococcus aureus and Enterobacter cloacae (wound sample) and S. aureus, Finegoldia magna, and Corynebacterium xerosis (fracture site samples). As there was no tendency toward healing, a further surgery with new lateral and medial plating was performed. The distal wound lesion was covered with a MESH graft. Post surgical therapy included mobilization with full weight bearing. In addition, osteoanabolic therapy with Teriparatide (250 µg/ml, Lilly Germany GmbH, Bad Homburg) to improve fracture healing was applied. Antibiotic treatment was continued for 6weeks. Histological examination confirmed an underlying chronic bone infection and the nonunion. The blood counts were normal when the patient was discharged after 27 days. 2 weeks after hospital discharge, the patient reported a sudden, atraumatic pain with immobilization. X-rays documented a fracture dislocation with the failure of the medial and lateral device and, in addition to these findings, a new distal fracture of the fibula (). There were no signs of consolidation at the former fracture site, and revision surgery was necessary. With the exception of two broken screw bodies, all devices were removed. A triple-plate reosteosynthesis was performed, including a 14-hole inverse LISS plate on the medial side, a 12-hole limited contact dynamic compression (LCDC) plate at the dorsal tibia aspect, and a 7-hole reconstruction plate at the new distal fibula fracture (all devices, Synthes GmBH, Umkirchbei Freiburg, Germany, ). The nonunion was resected, and the lesion was filled with an equilateral autologous spongiosa graft of the femur taken by a reamer-irrigator-aspirator system. A multidrug-resistant Staphylococcus epidermidis (MRSE) was isolated from the microbiological samples. Since the MRSE had also been isolated during prior surgeries, it was considered a major pathogen; therefore, antibiotic treatment with cefuroxime and clindamycin was changed to vancomycin (2 × 1 g, MIP Pharma GmbH, Blieskastel, Germany) and rifampicin (2 x 600 mg, Riemser Pharma GmbH, Greifswald, Germany). The patient was discharged with an oral combination of linezolid (2 × 600 mg, MIP Pharma GmbH, Blieskastel, Germany) and rifampicin (2 × 600 mg, Riemser Pharma GmbH, Greifswald, Germany) for additional 4weeks. Blood values were taken frequently, revealing normal WBC counts and regressive CRP values. A follow-up was planned at our outpatient clinic at the end of the period of unloaded mobilization 8weeks after surgery. The initial follow-up and subjective outcome were satisfactory at 8weeks postoperatively. There was no evidence of a persistent infection. The patient had completed 2months of mobilization without weight bearing and had started partial weight bearing without any problems a few days before. Therefore, slowly increasing weight bearing to improve inpatient rehabilitation and functional outcome of the affected limb was recommended. The patient was readmitted from rehabilitation to our department in January 2015 due to a progression of knee pain and moderately elevated paraclinical values of infection. Examination at admission showed normal wounds at the fracture site, but at the knee, the skin was irritated and swollen. X-rays showed a small amount of new bone formation at the medial and lateral side of the former tibial fracture, but a fracture union was still not present. A knee puncture was performed, and the microbiological assessment showed a known MRSE, previously of the fracture site, now with a limited spectrum of sensitivity. A bone and leukocyte scintigraphy showed a persistent (infectious) nonunion and aseptic loosening of the TKA due to ascending infection. With the additional septic focus, there was a need for complete removal of all implants. Therefore, a two-stage implant change was planned. After removal of all implants, a deep debridement was performed, and a hand-formed bone cement knee spacer including antibiotics (Copal G+C 1 × 40 mg, Heraeus Medical GmbH, Wehrheim, Germany) was implanted. Microbiological and histological samples taken during surgery confirmed the chronic bone infection and septic TKA. An antibiotic treatment was started perioperatively and was given for 6weeks with a combination of vancomycin (2 × 1 g, MIP Pharma GmbH, Blieskastel, Germany) and rifampicin (2 × 600 mg, Riemser Pharma GmbH, Greifswald, Germany) followed by an oral mono-therapy with linezolid (2 × 600 mg, PHARMACIA GmbH, Karlsruhe, Germany). The mobilization was performed with full weight bearing using an individual constructed lower limb load-relieving orthosis by Allgöwer. After an antibiotic-free interval of 2 weeks, the patient was admitted for a diagnostic joint puncture. However, the knee puncture again showed purulent synovial fluid with the isolation of the prior known MRSE. The remaining broken screws and a bone abscess close to the former nonunion was removed within revision surgery. A tibial nail (T2, 315 × 10 mm, Stryker Trauma GmbH, Schönkirchen, Germany) was used for temporary intramedullary splinting and to provide further consolidation of the circumferential callus bone. Furthermore, a new bone cement spacer (Palacos R+G, 2× 40 mg, Heraeus Medical GmbH, Wehrheim, Germany) with two additional antibiotic-impregnated chains (2 × 30, Biomet Deutschland GmbH, Berlin, Germany) was implanted (). MRSE was ascertained everywhere except for the distal femur. In accordance with the pathogen’s spectrum of resistance, a new 6-week course of therapy with vancomycin (2 × 1 g, MIP Pharma GmbH, Blieskastel, Germany) was begun and switched to oraltherapy with linezolid (2 × 600 mg, PHARMACIA GmbH, Karlsruhe, Germany) only. The previous mobilization using the orthesis was continued. In August 2015, a puncture of the knee joint after an antibiotic-free interval showed no pathogens. Clinical examination was without any signs of persistent infection. X-rays showed only a partial consolidation of the fracture at the tibia, but the fibula was consolidated. Therefore, reimplantation of a special revision TKA, also addressing the tibial fracture was scheduled. Revision surgery included removing the nail and all other foreign bodies and an extensive debridement with reaming of the intramedullary cavity of the tibia. The surgery was completed by a partial replacement of the distal femur due to bone loss and a modular revision TKA was implanted (Mega C, modular tibia with a 14/280 mm cementless tibia stem, modular femur condyle with a 16/100 mm cemented stem, Waldemar Link GmbH and Co. KG, Hamburg, Germany; ). The tibial fracture site was splinted stable with the long cementless stem by the means of a press fit. Intraoperative range of motion of the knee joint was extension/flexion of 0/0/100. The patient underwent full weight bearing using two crutches and patient’s orthosis for 8weeks postoperatively. Post-operative X-rays showed no malalignment of the TKA and good fracture stabilization by the tibial stem. Laboratory counts and infectious values normalized, and there was a remarkable improvement in the patient’s quality of life. A new rehabilitation was scheduled after the inpatient time of 3weeks. The patient was discharged with an active ROM of 90° in flexion. He was able to exercise on an even track for more than 20 min. The patient underwent 4months of follow-up after successfully completing rehabilitation. The patient was able to walk under full weight bearing with the aid of two crutches. Occasionally, the orthosis is carried for long distances. He reported an intermittent pain at the superficial goose’s foot in cases of higher stress. There was a temporary relief after a local anesthetic infiltration, but the pain, in general, was described as moderate. All wounds were dry and without any signs of infection. The active range of motion was tested with flexion of 0/0/90°. The patient was seen for the last follow-up 15 months after revision TKA with only moderate pain at the medial knee site. Mobilization was performed with the use of one crutch, and knee flexion is limited to 80°, which is described as acceptable for patient’s daily activities. The patient is confident with the functional outcome and quality of life.removing the nail and all other foreign bodies and an extensive debridement with reaming of the intramedullary cavity of the tibia. The surgery was completed by a partial replacement of the distal femur due to bone loss and a modular revision TKA was implanted (Mega C, modular tibia with a 14/280 mm cementless tibia stem, modular femur condyle with a 16/100 mm cemented stem, Waldemar Link GmbH and Co. KG, Hamburg, Germany; ). The tibial fracture site was splinted stable with the long cementless stem by the means of a press fit. Intraoperative range of motion of the knee joint was extension/flexion of 0/0/100. The patient underwent full weight bearing using two crutches and patient’s orthosis for 8weeks postoperatively. Post-operative X-rays showed no malalignment of the TKA and good fracture stabilization by the tibial stem. Laboratory counts and infectious values normalized, and there was a remarkable improvement in the patient’s quality of life. A new rehabilitation was scheduled after the inpatient time of 3weeks. The patient was discharged with an active ROM of 90° in flexion. He was able to exercise on an even track for more than 20 min. The patient underwent 4months of follow-up after successfully completing rehabilitation. The patient was able to walk under full weight bearing with the aid of two crutches. Occasionally, the orthosis is carried for long distances. He reported an intermittent pain at the superficial goose’s foot in cases of higher stress. There was a temporary relief after a local anesthetic infiltration, but the pain, in general, was described as moderate. All wounds were dry and without any signs of infection. The active range of motion was tested with flexion of 0/0/90°. The patient was seen for the last follow-up 15 months after revision TKA with only moderate pain at the medial knee site. Mobilization was performed with the use of one crutch, and knee flexion is limited to 80°, which is described as acceptable for patient’s daily activities. The patient is confident with the functional outcome and quality of life.