Treatment of a Recurrent Periprosthetic Joint Infection with an Intramedullary Knee Arthrodesis System with Low-Amount Metallic Silver Coating

Therapy of a Chronically Infected Total Femur Prothesis in a 40-year-old Patient

We report a case of a patient who was treated in 1999 at the age of 19 years with a proximal femur replacement due to Ewing sarcoma. After several infection-associated exchange procedures, the patient presented with a fistula and chronic infection of a total femur prosthesis in August 2019 at the age of 40 years. Interdisciplinary treatment with a 3-stage exchange procedure and implantation of a silver-coated total femur prosthesis was successfully performed and hip disarticulation could be avoided. After a follow-up of 2 years, the patient showed uneventful wound healing and full weight bearing without crutches.

Treatment of a Gustilo-Anderson type II open tibia shaft fracture with an ultrathin silver plasma-coated plate: A case report

The treatment of open tibia fractures with plate fixation bears a high risk for the development of a fracture-related infection. Here we present a case of an 80-year-old female with a Gustilo-Anderson type II open distal tibial shaft fracture with an indwelling knee prosthesis. The case was successfully treated with a 2-stage procedure with initial external fixation and subsequent open reduction and plate fixation with a custom-made ultrathin silver plasma-coated locking plate. Plate fixation was the preferred method as the indwelling knee prosthesis prevented the use of a standard intramedullary tibia nail. The fracture healed uneventfully without any signs of infections and the patient achieved full weight-bearing with a normal gait and without any pain after three months. Radiographical full bridging of the initial fracture area was seen after 5 months without any signs of infection or fracture healing disturbances. After an overall follow-up of 12 months, there were no signs of silver associated or other adverse events. Thus, ultrathin silver plasma coating seems to be helpful in the treatment open fractures with plate fixation to prevent fracture-related infections.

Treatment of an infected nonunion with additional fresh fracture of the femur with a silver-coated intramedullary nail: A case report

Infected non-unions of the femur can be difficult to treat with a high risk of reinfection and persisting nonunion. Here we demonstrate a case of a 66-year-old female with a chronic infected nonunion of the left femur. The patient fell during temporary external fixation of the infected nonunion and sustained an additional proximal femur shaft fracture. The case was successfully managed with a low-amount silver coating of a long proximal femur nail and an additional augmentation locking plate along with local and systemic antibiotics. After a follow-up of 26 months, both the fracture and also the infected nonunion healed completely without recurrence of infection and without any signs of adverse events in response to the silver coating. In conclusion, silver coated fracture fixation devices can be helpful in difficult to treat infection cases without adverse events.

Low complication rate and better results for intramedullary nail - arthrodesis for infected knee joints compared to external fixator-a series of one hundred fifty two patients

PURPOSE

Arthrodesis of the knee joint is still a salvage procedure after recurrent prosthetic joint infections (PJI) of total knee arthroplasties (TKA) with substantial bone loss and seems to be a good solution to avoid amputation. Until now, intramedullary arthrodesis has increasingly been performed; no study has yet been published to compare these techniques after septic removal of TKA in terms of functional assessment and quality of daily life.

METHODS

In a single-centre retrospective setting, clinical and radiographic evaluation of consecutive patients after knee arthrodesis using intramedullary and external fixation for infected knee joints was performed. All patients were evaluated clinically, with x-ray and questionnaire including analysis regarding any complications at latest follow-up of a minimum 12 months postoperatively.

RESULTS

We included 152 patients (75 females, 77 males) in this study. The mean age of the patients at surgery was 63.6 years (range 12 to 90 years). The minimum follow-up was 12 months (mean 3.1 years, range 12 to 49 months). Arthrodesis with external fixator (83 patients, 52.2%) showed less blood loss and less peri-operative complications (1.6%) but a high rate of post-operative, pin-track infections (35.5%); loose pins (12.7%); and pin fractures (4.8%), and therefore risk factors for instability and nonunion (30.9%). Revision rate was 22.6% for arthrodesis with external fixator, and the primary union rate was 65.6%. Intramedullary arthrodesis (69 patients, 43.4%) showed a similar re-infection rate to external fixation (16.1% and 15.9%, respectively) but a significantly lower revision rate (5.4%, p < 0.001). Eighty percent of patients with intramedullary arthrodesis showed very good patient-related outcomes regarding pain, function and daily life activities in the questionnaire.

CONCLUSION

Despite similar results regarding patient satisfaction and everyday competences in questionnaires, intramedullary arthrodesis of the knee is superior to the external fixator, as it results in fewer complications, lower revision rate, and union rates/loosening.

Antimicrobial Silver Multilayer Coating for Prevention of Bacterial Colonization of Orthopedic Implants

Due to increasing rates of periprosthetic joint infections (PJI), new approaches are needed to minimize the infection risk. The first goal of this study was to modify a well-established infection model to test surface-active antimicrobial systems. The second goal was to evaluate the antimicrobial activity of a silver multilayer (SML) coating. In vitro tests with SML items showed a >4 Log reduction in a proliferation assay and a 2.2 Log reduction in an agar immersion test (7 d). In the in vivo model blank and SML coated K-wires were seeded with ~2 × 104 CFU of a methicillin-sensitive Staphylococcus epidermidis (MSSE) and inserted into the intramedullary tibial canal of rabbits. After 7 days, the animals were sacrificed and a clinical, microbiological and histological analysis was performed. Microbiology showed a 1.6 Log pathogen reduction on the surface of SML items (p = 0.022) and in loosely attached tissue (p = 0.012). In the SML group 7 of 12 SML items were completely free of pathogens (cure rate = 58%, p = 0.002), while only 1 of 12 blank items were free of pathogens (cure rate = 8%, p = 0.110). No silver was detected in the blood or urine of the SML treated animals and only scarcely in the liver or adjacent lymph nodes. In summary, an in vivo infection model to test implants with bacterial pre-incubation was established and the antimicrobial activity of the SML coating was successfully proven.