When treating periprosthetic femur fractures (PPFFs) around total hip arthroplasty (THA)], determining implant fixation status preoperatively is important, since this guides treatment regarding ORIF versus revision. The purpose of this study was to determine the accuracy of preoperative implant fixation status determination utilizing plain films and CT scans. Twenty-four patients who underwent surgery for Vancouver B type PPFF were included in the study. Two joint surgeons and two traumatologists reviewed plain films alone and made a judgment on fixation status. They then reviewed CT scans and fixation status was reassessed. Concordance and discordance were recorded. Interobserver reliability was assessed using Kendall's W and intraobserver reliability was assessed using Cohen's Kappa. Ultimately, the “correct” response was determined by intraoperative findings, as we routinely test the component intraoperatively. Fifteen implants were found to be well-fixed (63%) and 9 were loose. Plain radiographs alone predicted correct fixation status in 53% of cases. When adding the CT data, the correct prediction only improved to 55%. Interestingly, concordance between plain radiographs and CT was noted in 82%. In concordant cases, the fixation status was found to be correct in 55% of cases. Of the 18% of cases with discordance, plain films were correct in 43% of cases, and the CT was correct in 57%. Interobserver reliability demonstrated poor agreement on plain films and moderate agreement on CT. Intraobserver reliability demonstrated moderate agreement on both plain films and CT. The ability to determine fixation status for proximal PPFFs around uncemented femoral components remains challenging. The addition of routine CT scanning did not significantly improve accuracy. We recommend careful intraoperative testing of femoral component fixation with surgical dislocation if necessary, and the surgeon should be prepared to revise or fix the fracture based on those findings.
Periprosthetic infection is a challenging complication of total knee arthroplasty (TKA) which reported incidence varies from 1 to 2% in primary TKA and 3–5% in revision TKA. Persistent infection of TKA may benefit from knee arthrodesis when all reconstruction options have failed. Knee arthrodesis also demonstrated better functional results and pain relief than other salvage procedures such as above-knee amputation. The purpose of this study was to analyze treatment results in patients who underwent knee arthrodesis following infected TKA. Retrospective study with review of the data of all patients treated in our department with knee arthrodesis for chronic infection of knee arthroplasty between 2009 and 2014. Clinical and radiographic data were evaluated as well as several variables: technique used, fusion rate, time to fusion, need for further arthrodesis and complications. Patients with less than 8 months of follow-up were excluded from this study. 46 patients were treated with knee arthrodesis in our department from 2009 to 2014 for chronic infection of total knee arthroplasty. The sample included 26 (57%) women and 20 (43%) men, median age of 70 years. In 45 patients, the technique used was compressive external fixation, while an intramedullary modular nail was used in 1 patient. Mean follow-up of these patients was 35 months (8–57). Primary knee fusion was obtained in 32 (70%) patients with a mean time to fusion of 5,8 months (4–9). 9 (20%) patients needed rearthrodesis and 7 (15%) ultimately achieved fusion. 33 (72%) patients underwent knee arthrodesis in a single surgical procedure, while 13 (28%) firstly removed knee arthroplasty and used a spacer before arthrodesis. Overall complication rate was 35%; 7 (15%) patients experienced persistent infection and 4 (9%) of these undergone above knee amputation. Treatment of septic total knee replacement is a surgical challenge. Compressive external fixation was the method of choice to perform knee arthrodesis following chronic infected TKA. Although complication rate was worrisome, overall fusion rate was satisfactory and this arthrodesis method can be safely performed in one stage.
