Reproducibly achieving proper implant alignment is a critical step in total hip arthroplasty procedures that has been shown to substantially affect patient outcome. In current practice, correct alignment of the acetabular cup is verified in C-arm x-ray images that are acquired in an anterior–posterior (AP) view. Favorable surgical outcome is, therefore, heavily dependent on the surgeon’s experience in understanding the 3-D orientation of a hemispheric implant from 2-D AP projection images. This work proposes an easy to use intraoperative component planning system based on two C-arm x-ray images that are combined with 3-D augmented reality (AR) visualization that simplifies impactor and cup placement according to the planning by providing a real-time RGBD data overlay. We evaluate the feasibility of our system in a user study comprising four orthopedic surgeons at the Johns Hopkins Hospital and report errors in translation, anteversion, and abduction as low as 1.98 mm, 1.10 deg, and 0.53 deg, respectively. The promising performance of this AR solution shows that deploying this system could eliminate the need for excessive radiation, simplify the intervention, and enable reproducibly accurate placement of acetabular implants.
Partly due to above drawbacks, surgeons who use the DAA often rely solely on fluoroscopic image guidance @cite_45 @cite_24 . These images, however, are a 2D representation of 3D reality and have inherent flaws that complicate the assessment. The challenges include finding the true anterior pelvic plane as well as eyeballing acetabular component position by eye on the image. Therefore, a technique that provides a quantitative and reliable representation of the pelvis and acetabular component intra-operatively without increasing neither radiation dose or cost while largely preserving the procedural workflow is highly desirable.
@cite_24 @cite_45
2010367405 119128115
Abstract Benefits of a direct anterior approach (DAA) versus a posterior-lateral (PA) approach to THA were assessed in a single-surgeon, IRB-approved, prospective, randomized clinical study. Subjects (43 DAA and 44 PA) were evaluated at 6weeks, and 3, 6 and 12months. The primary end point was ability to climb stairs normally and walk unlimited at each time point. Secondary end points included assessment by several outcome instruments. DAA subjects performed better during the immediate post-operative period; they had lower VAS pain scores on the first post-operative day, more subjects climbing stairs normally and walking unlimited at 6weeks, and higher HOOS Symptoms scores at 3months. There were no significant differences between groups at later time points. Findings confirm previous reports of benefits of DAA versus PA in early post-operative phases. Abstract The authors conducted a retrospective, multicenter cohort study of 1,152 patients across nine clinical sites across the United States, evaluating complications and function associated with the anterior approach to total hip arthroplasty using an orthopedic table. Eligible patients included those with primary diagnosis of hip arthritis. Outcomes included hospital stay, use of assistive devices, complications, and function. In the cohort of 1,152 patients treated with the anterior approach to total hip arthroplasty, the authors found (i) an acceptable complication profile with a very low dislocation rate, (ii) an early return to function, and (iii) a decline in complications in surgeons with greater than 100 case experiences.