Imageless versus image-based registration in navigated arthroscopy of the hip: a cadaver-based assessment.
ABSTRACT The aim of this study was to determine the accuracy of registration and the precision of the resection volume in navigated hip arthroscopy for cam-type femoroacetabular impingement, using imageless and image-based registration. A virtual cam lesion was defined in 12 paired cadaver hips and randomly assigned to either imageless or image-based (three-dimensional (3D) fluoroscopy) navigated arthroscopic head-neck osteochondroplasty. The accuracy of patient-image registration for both protocols was evaluated and post-operative imaging was performed to evaluate the accuracy of the surgical resection. We found that the estimated accuracy of imageless registration in the arthroscopic setting was poor, with a mean error of 5.6 mm (standard deviation (sd) 4.08; 95% confidence interval (CI) 4.14 to 7.19). Because of the significant mismatch between the actual position of the probe during surgery and the position of that probe as displayed on the navigation platform screen, navigated femoral osteochondroplasty was physically impossible. The estimated accuracy of image-based registration by means of 3D fluoroscopy had a mean error of 0.8 mm (sd 0.51; 95% CI 0.56 to 0.94). In terms of the volume of bony resection, a mean of 17% (sd 11; -6% to 28%) more bone was resected than with the virtual plan (p = 0.02). The resection was a mean of 1 mm deeper (sd 0.7; -0.3 to 1.6) larger than on the original virtual plan (p = 0.02). In conclusion, given the limited femoral surface that can be reached and digitised during arthroscopy of the hip, imageless registration is inaccurate and does not allow for reliable surgical navigation. However, image-based registration does acceptably allow for guided femoral osteochondroplasty in the arthroscopic management of femoroacetabular impingement.
SourceAvailable from: Vikas Khanduja[Show abstract] [Hide abstract]
ABSTRACT: The technical advances in arthroscopic surgery of the hip, including the improved ability to manage the capsule and gain extensile exposure, have been paralleled by a growth in the number of conditions that can be addressed. This expanding list includes symptomatic labral tears, chondral lesions, injuries of the ligamentum teres, femoroacetabular impingement (FAI), capsular laxity and instability, and various extra-articular disorders, including snapping hip syndromes. With a careful diagnostic evaluation and technical execution of well-indicated procedures, arthroscopic surgery of the hip can achieve successful clinical outcomes, with predictable improvements in function and pre-injury levels of physical activity for many patients.This paper reviews the current position in relation to the use of arthroscopy in the treatment of disorders of the hip.Cite this article: Bone Joint J 2013;95-B:10-19.01/2013; 95-B(1):10-9. DOI:10.1302/0301-620X.95B1.29608
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ABSTRACT: Successful outcomes after orthopedic surgical procedures are believed to be highly dependent on reproducible anatomic accuracy. Immediate intraoperative feedback helps surgeons to achieve this accuracy as has been demonstrated with the use of fluoroscopy. Non-image-based computer navigation has been used in joint arthroplasty, anterior cruciate ligament reconstruction, high tibial osteotomy, and cartilage procedures along with applications in hip and shoulder arthroscopy. Most short-term studies have demonstrated superior accuracy when compared with conventional techniques; however, very few studies have shown better clinical outcomes. Robotic-assisted surgery has been most popular in total and unicompartmental arthroplasty, which again has greater accuracy but similar clinical outcomes when compared with conventional techniques. Economic analyses indicate that these high-cost technologies may only be cost-effective in high-volume centers. Other studies have shown that computer navigation improves the accuracy of lower volume surgeons to a greater degree than higher volume surgeons allowing the former to have results similar to the latter.
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ABSTRACT: In recent years, robots have become commonplace in surgical procedures due to their high accuracy and repeatability. The Acrobot Sculptor is an example of such a robot that can assist with unicompartmental knee replacement. In this study, we aim to evaluate the accuracy of the robot (software and hardware) in a clinical setting. We looked at (1) segmentation by comparing the segmented data from Sculptor software to other commercial software, (2) registration by checking the inter- and intraobserver repeatability of selecting set points, and finally (3) sculpting (n = 9 cases) by evaluating the achieved implant position and orientation relative to that planned. The results from segmentation and registration were found to be accurate. The highest error was observed in flexion extension orientation of femoral implant (0.4 ± 3.7°). Mean compound rotational and translational errors for both components were 2.1 ± 0.6 mm and 3 ± 0.8° for tibia and 2.4 ± 1.2 mm and 4.3 ± 1.4° for the femur. The results from all processes used in Acrobot were small. Validation of robot in clinical settings is highly vital to ensure a good outcome for patients. It is therefore recommended to follow the protocol used here on other available similar products.09/2013; 2013:194683. DOI:10.1155/2013/194683