Fluoroscopic Intraoperative Images Produce Higher Image Quality and Decrease Total Radiation Exposure Compared to Radiographic X-ray Images in Patients After Primary Total Knee Arthroplasty

Abstract

Background/Aim: Proper radiographic documentation of implant alignment is needed to analyse malrotation and malpositioning. We examined whether intraoperative fluoroscopic images can achieve more accurate image quality than postoperative radiographic Xray images. Patients and Methods: We prospectively analysed 30 consecutive patients after total knee arthroplasty (TKA). We compared intraoperative fluoroscopic images with postoperative radiographic X-ray images. Radiation exposure was documented. Results: Fluoroscopic anteriorposterior images could achieve accurate image quality in 77% compared to 60% in radiographic images (p=0.016) and 54% compared to 34% on lateral view, respectively (p=0.008). Very good intra-observer correlation for fluoroscopic images could be achieved for femoral α angle with 0.84. Radiation exposure was 0.087+/-0.128 mGy. Conclusion: We observed significantly better image quality in fluoroscopic images than in radiographic X-ray images. The observed radiation exposure is lower than those expected for radiographic X-ray images. We conclude that fluoroscopic images can produce higher image quality and decreased radiation exposure. Exact component fixation and alignment of total knee arthroplasty (TKA) is imperative to reduce postoperative pain and obtain patient satisfaction and good clinical function (1-4). Therefore proper radiographic documentation of coronal and sagittal implant alignment is needed to analyse malrotation and malpositioning (5, 6). Due to a lack of consistency in roentgenographic reporting of findings, rating systems have been described (2, 5, 7). The original Knee Society Clinical Rating System had been described in 1989 by Ewald et al. and has been adapted by Meneghini et al. They intended to modernized and updated the radiographic evaluation system as a rising diversity and complexity in implant design came up. Therfore they aimed to accumulate radiographic data in a standardized manner (5, 7, 8). In addition, a well aligned postoperative image is inevitable for compareability to detect implant loosening over time. However, accurate and precise radiographic images are difficult to obtain as they depend on several parameters. Using either standing or portable radiographs for the measurement of the knee joint centre gives significant different values due to changes in the rotation of the knee in the presence of knee flexion (9). Limb rotation and knee flexion of 10˚, either alone or in combination, has a significant effect on measured values of the anatomic alignment (10-13). Further patients' specific parameters like pain and casts can make proper radiograph acquisition challenging. Looking for improvement of measured parameter reliability and reproducibility, the use of 3D-CT has shown better reliability than 2D-CT. However, radiation exposure is much higher compared to radiographic X-ray images (1, 14). The use of intraoperative fluoroscopy of the anaesthetized patient reduces the patient's incompliances due to pain and 2521 This article is freely accessible online.

Computed tomography and fluoroscopy versus radiographic guidance for internal fixation of simulated dorsomedial‐plantarolateral central tarsal bone fractures in nonracehorses

“…In the population of nonracehorses at this institution, CT has identified comminution in several cases in which screw insertion based on the radiographic appearance alone may have resulted in worsening of the fracture. Additionally, when fluoroscopy is used for intraoperative guidance, there is the potential for lower cumulative radiation doses compared to digital radiography 16 depending on the unit type, settings, and number of images taken. Unfortunately, CT and fluoroscopy are not available to every practitioner.…”