scholarly journals Clinical Validation of Computer-Assisted Navigation in Total Hip Arthroplasty

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Eric Beaumont ◽  
Pierre Beaumont ◽  
Daniel Odermat ◽  
Isabelle Fontaine ◽  
Herbert Jansen ◽  
...  

A CT-based navigation system is helpful to evaluate the reamer shaft and the impactor position/orientation during unilateral total hip arthroplasty (THA). The main objective of this study is to determine the accuracy of the Navitrack system by measuring the implant's true anteversion and inclination, based on pre- and postoperative CT scans (n=9patients). The secondary objective is to evaluate the clinical validity of measurements based on postop anteroposterior (AP) radiographs for determining the cup orientation. Postop CT-scan reconstructions and postop planar radiographs showed no significant differences in orientation compared to peroperative angles, suggesting a clinical validity of the system. Postoperative AP radiographs normally used in clinic are acceptable to determine the cup orientation, and small angular errors may originate from the patient position on the table.

2020 ◽  
Vol 31 (3) ◽  
pp. 211-217
Author(s):  
Rachel R. Mays ◽  
Jessica R. Benson ◽  
Jeffrey M. Muir ◽  
Morteza Meftah

10.29007/3lbz ◽  
2019 ◽  
Author(s):  
Morteza Meftah ◽  
Vinnay Siddappa ◽  
Jeffery Muir ◽  
Peter White

Computer-assisted navigation has the potential to improve the accuracy of cup positioning during total hip arthroplasty (THA) and prevent leg length discrepancy (LLD). The purpose of this study was to compare acetabular cup position and post- operative LLD after primary THA using posterolateral approach. Between August 2016 to December 2017, 57 THAs using imageless navigation were matched with 57 THA without navigation, based on age, gender and BMI. Post-operative weight-bearing radiographs were assessed using for anteversion, inclination and LLD. Goal for functional cup placement was 40° inclination and 20° anteversion based on preoperative weight bearing pelvic images. Functional LLD was measured as compared to pre- operative radiographs and contralateral side. Proportion of cups within Lewinnek’s safe zone, proximity to a pre-operative target of and the LLD >5 mm was assessed. The mean age was 54.9 ± 9.6 years (30 – 72) and 57.6 ± 12.5 years (20 – 85) in control and navigated groups, respectively. Mean cup orientation in the navigated group was 20.6°± 3.3° (17 - 25) of anteversion and 41.9°± 4.8° (30 - 51) of inclination, vs. 25.0°± 11.1° (10 - 31) and 45.7°± 8.7° (29 – 55) in control group, where were statistically significant (p=0.005 and p=0.0001), respectively. In the navigated group, significantly more acetabular cups were placed within Lewinnek’s safe zone (anteversion: 78% vs. 47%, p=0.005; inclination: 92% vs. 67%, p=0.002). There was no significant difference in mean LLD in navigation and control groups (3.1 ± 1.5 mm vs. 4.6 ± 3.4 mm, p=0.36), although fewer LLDs >5 mm were reported in the navigated group (7.1%) than in controls (31.4%, p=0.007). The use of this image-less computer-assisted navigation improved the accuracy with which acetabular cup components were placed and may represent an important method for limiting post-operative complications related to cup malpositioning and LLD.


2017 ◽  
Vol 01 (02) ◽  
pp. 105-111
Author(s):  
Jonathan Vigdorchik ◽  
MIchael Cross ◽  
Theodore Miller ◽  
Eric Bogner ◽  
Jeffrey Muir ◽  
...  

AbstractInaccurate placement of components during total hip arthroplasty (THA) can lead to significant postoperative complications including revision surgery. Traditionally, surgeons grossly estimate component positioning intraoperatively using anatomical landmarks; however, evidence indicates that this surgeon assessment may not be reliable. The purpose of this study was to determine the accuracy of surgeon estimates of component position as compared with imaging (radiographs and computed tomography [CT] scan) and a new surgical navigation system. Three board-certified orthopaedic surgeons each performed four THA procedures on six cadavers (12 hips). Radiographs and CT scans were obtained postoperatively. The “gold standard” measurements of implanted cup anteversion and inclination were derived from three-dimensional renderings created from postoperative CTs. A reference value for cup position was created by aligning the anterior pelvic plane in each rendering coplanar with the CT table. Following each procedure, surgeons provided their estimate of acetabular cup component orientation. Surgeon estimates were compared with data gathered from postoperative radiographs, CT scans, and the navigation device. Surgeon estimates of anteversion and inclination were within 10 degrees of reference values in 64% (7/11) and 82% (9/11) of cases, respectively. Surgeon estimates of anteversion differed from reference values by a mean of 7.6 ± 5 degrees, whereas inclination differed from reference values by a mean of 6.1 ± 5.1 degrees (all means absolute). Radiographic measurements differed from reference values by 7.8 ± 4.3 degrees (p > 0.05) and 2.7 ± 2.3 degrees (p = 0.06) for anteversion and inclination, respectively, whereas CT values differed by 2.5 ± 1.6 degrees (p = 0.004) and 2.3 ± 2.1 degrees (p = 0.04). The navigation system differed from reference values by 4 ± 4 degrees (p = 0.08) and 4.2 ± 3.2 degrees (p = 0.31). Surgeons underestimated anteversion and inclination by 7.7 ± 4.8 degrees and 6.9 ± 4.8 degrees, respectively. Surgeon underestimation was observed in 8/11 (73%) cases, with anteversion underestimated by > 5 degrees in 5/8 (62%) cases and inclination underestimated by > 5 degrees in 4/8 (50%) cases. Our findings suggest that surgeons tend to underestimate both anteversion and inclination and that the accuracy of their estimates is similar to that of radiographs. CT scans and the navigation system were able to provide more accurate measurements of cup position.


Author(s):  
Jonathan M. Vigdorchik ◽  
Peter K. Sculco ◽  
Allan E. Inglis ◽  
Ran Schwarzkopf ◽  
Jeffrey M. Muir

2020 ◽  
Author(s):  
Kentaro Iwakiri ◽  
Yoichi Ohta ◽  
Yohei Ohyama ◽  
Yukihide Minoda ◽  
Akio Kobayashi ◽  
...  

Abstract Background Background: Stem anteversion is important in reducing postoperative complications in total hip arthroplasty (THA). THA utilizing the combined-anteversion theory requires stem anteversion angle (SAA) measurement intraoperatively; however, intraoperative SAA estimation is difficult for surgeons without computer-assisted navigation system. We evaluated the accuracy of the SAA measured intraoperatively using a newly developed device by comparing the three-dimensional measurements using postoperative computed tomography (CT).Materials & Methods In 127 hips in 127 patients who underwent unilateral THA at our hospital, we used our newly developed device that can be easily attached to rasping broach handles for measuring the SAA intraoperatively, which required the addition of the correction angle obtained in the preoperative epicondylar view. Postoperative SAA and its discrepancies from the measured intraoperative SAA with or without adding the correction angle were compared between the groups to evaluate the usefulness of the device.Results The intraoperative SAA measured by the device was 17.93 ± 7.53°. The true SAA measured on postoperative CT was 26.40 ± 9.73°. The discrepancy between the intraoperative SAA and true SAA was 8.94 ± 5.44° (without the correction angle), and 4.93 ± 3.85° (with the correction angle). Accuracy with a discrepancy of <5 degrees was achieved in 77 (60.6%) and <10 degrees was achieved in 113 (89.0%). The accuracy was unaffected by the stem placement angle (varus/valgus, or flexion/extension), or ipsilateral knee osteoarthritis.Conclusion The SAA measuring device, easily attachable to various rasping handles, is useful to measure the intraoperative SAA in a simple, economical, and noninvasive manner during THA.Level of Evidence Therapeutic Level IV.


Sign in / Sign up

Export Citation Format

Share Document