ABSTRACT
Background@#The number of revision total knee arthroplasty (TKA) has been increasing. Although many studies have analyzed the causes of revision TKA in Western countries, a limited number of studies have analyzed changes in causes of or trends in revision TKA in Asia. This study analyzed and determined the frequency and causes of failures after TKA in our hospital. We also analyzed the differences and trends over the past 17 years. @*Methods@#A total of 296 revision TKAs performed in a single institution from 2003 to 2019 were analyzed. During the 17-year study period, patients who had undergone primary TKA between 2003 and 2011 were classified into a past group, while those who had undergone primary TKA from 2012 to 2019 were classified into a recent group. A revision performed within 2 years after primary TKA was defined as early revision. Further, differences in causes of revision TKA according to the interval from primary TKA to revision TKA were determined. The causes of revision TKA were analyzed through a comprehensive analysis of patients’ medical records. @*Results@#Overall, infection was the most common cause of failure (151/296 cases, 51.0%). Compared to the past group, the recent group had a relatively higher proportion of patients undergoing revision TKA for mechanical loosening (past group, 19.1% vs.recent group, 31.9%) and instability (11.2% vs. 13.5%) and a relatively lower proportion of patients undergoing revision TKA for infection (56.2% vs. 48.8%), polyethylene (PE) wear (9.0% vs. 2.9%), osteolysis (2.2% vs. 1.9%), and malalignment (2.2% vs. 1.0%).On comparison according to the interval from primary TKA to revision TKA, the rate of infection relatively decreased, whereas the rate of mechanical loosening and instability relatively increased in the late revision TKA compared to the early revision TKA. @*Conclusions@#Infection and aseptic loosening were the most common reasons of revision TKA in both past and recent groups.Compared to the past, revision TKA due to PE wear has decreased significantly and revision TKA due to mechanical loosening has relatively increased recently. Orthopedic surgeons need to be aware of recent trends in mechanisms of failure and should try to recognize and address the probable causes in TKA
ABSTRACT
Background@#Revision total knee arthroplasty (RTKA) is a technically demanding procedure for failed primary TKA. Posterior-stabilized (PS) and constrained condylar knee (CCK) articulations are commonly used for RTKA, but comparison of these articulations in RTKA is scarce. The aim of this study was to compare survival rates and clinical outcomes of RTKAs using PS articulation and CCK articulation. @*Methods@#This study conducted a retrospective analysis of 86 RTKAs (PS, n = 41; CCK, n = 45) with a mean follow-up of 9.15 ± 2.79 years. Clinical outcomes were evaluated using the Hospital for Special Surgery score, Knee Society Score, and The Western Ontario and McMaster Universities Osteoarthritis Index at final follow-up. The survival rate of each group was analyzed by KaplanMeier survival analysis and Cox-hazard progression model. @*Results@#Clinical outcomes were improved in both groups without significant difference. Twelve patients had orthopedic complications (4 in PS group and 8 in CCK group). Eight of them underwent re-RTKA (3 in PS group and 5 in CCK group). The articulation design did not influence the failure. The estimated 10-year survival rate was 92.7% in the PS group and 88.2% in the CCK group with no significant difference (p = 0.60). Also in septic failure, there was no significant difference in survival rate (92.7% in PS group and 92.5% in CCK group, p = 0.87). The hazard ratio in the PS group was not significantly different (p = 0.607). @*Conclusions@#In RTKA, both PS and CCK showed similar survival rates and clinical outcomes at a mean follow-up of 9.2 years. Implant articulation did not affect the outcomes when properly indicated
ABSTRACT
Purpose@#This study aimed to evaluate and compare the accuracy of the size of the posterior malleolar fragment measured using lateral plain radiography and three-dimensional computed tomography (3DCT) in patients with ankle trimalleolar fractures. @*Materials and Methods@#This study enrolled 80 patients (80 ankles) with ankle trimalleolar fractures and analyzed the size of the posterior malleolar fragments using plain radiography and 3D-CT. The articular involvement of the posterior malleolar fragments was measured as a percentage of the articular surface in the sagittal length of the tibial plafond using lateral plain radiography, and the articular surface area was directly measured using 3D-CT. In addition, we classified the patients into three groups based on the morphology of the posterior malleolar fracture, according to the Haraguchi classification method, and evaluated and compared the accuracy of the size of the posterior malleolar fragments. @*Results@#The mean articular involvement of the posterior malleolar fragments on plain radiography was 27.6% (range, 6.0%-53.1%), which was significantly higher than the mean of 21.9% (range, 4.7%-47.1%) measured using 3D-CT (p=0.004). In the analysis, according to the fracture morphology, the mean difference between the two methods was the largest for type I fractures at 9.1% (range, 1.8%-19.5%) and the smallest for type II fractures at 1.1% (range, –7.7% to 8.8%). @*Conclusion@#The articular involvement of posterior malleolar fragments measured using plain radiography showed low accuracy and significantly higher values than the actual articular involvement. Therefore, careful evaluation using 3D-CT is crucial for accurate analysis and optimal treatment in patients with ankle trimalleolar fractures.
