scholarly journals Accuracy of Image-less Navigation for Functional Cup Positioning in Total Hip Arthroplasty

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.

2020 ◽  
Author(s):  
Xiangpeng Kong ◽  
Minzhi Yang ◽  
Xiang Li ◽  
Ming Ni ◽  
Guoqiang Zhang ◽  
...  

Abstract Background: The purpose of this study was to examine whether surgeon handedness could affect cup positioning in manual total hip arthroplasty (THA), and whether robot could diminish or eliminate the impact of surgeon handedness on cup positioning in robot-assisted THA.Methods: Fifty-three patients who underwent bilateral robot-assisted THA and sixty-two patients who underwent bilateral manual THA between August 2018 and July 2019 in our institute were respectively analyzed in this study. When the difference between the bilateral anteversion or inclination was greater than 5°, the patient was regarded as having different cup positioning between bilateral THA. Their demographics, orientation of acetabular cup and postoperative 3 month Harris hip score (HHS) were recorded for analysis. Results: There were no significant difference in the gender, age, BMI, diagnosis’s composition, preoperative and postoperative HHS between the robotic and manual group. Two left hips dislocated in the manual group. The anteversion of left hip was significantly larger than that of right hip (24.77±10.44 vs 22.44±8.67, p=0.043) in the manual group. There were no significant difference of cup positioning between bilateral robot-assisted THA. The patients in manual group were significantly more likely to have different cup positioning between bilateral hips than those in robotic group (77% vs 45%, p=0.000). More manual THA were located out of the target zone than robot-assisted THA (70% vs 48%, p=0.001). Conclusions: Surgeon’s handedness showed a trend towards an impact on cup positioning in manual THA and robot might help surgeon eliminate the adverse impact. However, the impact of handedness on the clinical outcomes still needs further observation.


10.29007/jn8x ◽  
2019 ◽  
Author(s):  
Rachel Mays ◽  
Jessica Benson ◽  
Jeffrey Muir ◽  
Peter White ◽  
Morteza Meftah

Proper positioning of the acetabular cup deters dislocation after total hip arthroplasty (THA). The concept of a safe zone (SZ) for acetabular component placement was first characterized by Lewinnek et al. and furthered by Callanan et al. The SZ concept remains widely utilized and accepted in contemporary THA practice; however, components positioned in this SZ still dislocate. This study sought to characterize current mass trends in cup position identified across a large study sample of THA procedures completed by multiple surgeons. This retrospective, observational study reviewed acetabular cup position in 1,236 patients who underwent THA using computer-assisted navigation between July 2015 and November 2017. The overall mean cup position of all recorded cases was 21.8° (±7.7°, 95% CI = 6.7°, 36.9°) of anteversion and 40.9° (±6.5°, 95% CI = 28.1°, 53.7°) of inclination. For both anteversion and inclination, 65.5% (809/1236) of acetabular cup components were within the Lewinnek SZ and 58.4% (722/1236) were within the Callanan SZ. Acetabular cups were placed a mean of 6.8° of anteversion (posterior/lateral approach: 7.0°, anterior approach: 5.6°) higher than the Lewinnek and Callanan SZs whereas inclination was positioned 0.9° higher than the reported Lewinnek SZ and 3.4° higher than the Callanan SZ. Our data shows that while the majority of acetabular cups were placed within the traditional SZs, the mean anteversion orientation is considerably higher than those suggested by the Lewinnek and Callanan SZs. The implications of this observation warrant further investigation.


2018 ◽  
Vol 26 (2) ◽  
pp. 230949901878075 ◽  
Author(s):  
Kwang Jun Oh ◽  
Byung Kag Kim ◽  
Myung Il Jo ◽  
Byung Mun Ahn

Introduction: The purpose of this study was to compare acetabular cup positioning using an imageless navigation-assisted total hip arthroplasty (THA) to a case-matched control group using the conventional technique in Asian physique. Methods: Case matching controlled study using retrospectively collected data for THAs was done. Matching criteria were gender, age ± 5 years, and body mass index ± 5 kg/m2. Thirty patients who had navigation THAs were manually matched to a conventional group of 30 patients. After measuring anteversion and inclination on 3-D CT, final cup anteversion was calculated using the mathematical formula (anteversion = arctan [tan (anatomic anteversion) × sin (inclination)]). Results: No significant difference was observed between mean inclination ( p = 0.420), anteversion ( p = 0.697), and the mean deviation from 15° for anteversion ( p = 0.649). However, there was a statistical significant difference for mean deviation from 40° for inclination ( p = 0.027). There was a significant difference in the percentage of correctly placed acetabular cup in safe zones with inclination ( p = 0.039). Conclusions: Although soft tissue overlying the pubic tubercle interfered with registration of the bony landmark and thereby induced inaccuracy of anteversion angles in the navigation group, the use of imageless navigation-assisted technique increases the placement within the safe zone for inclination and enhances the accuracy and the precision of inclination of the acetabular cup relative to the conventional THA rather than anteversion. This finding may be due to the effect of the patient’s physique on the anterior pelvic plane (APP)-based reference system of imageless navigation.


2018 ◽  
Vol 12 (1) ◽  
pp. 389-395 ◽  
Author(s):  
Alexander Christ ◽  
Danielle Ponzio ◽  
Michael Pitta ◽  
Kaitlin Carroll ◽  
Jeffrey M. Muir ◽  
...  

Background: Computer-assisted navigation has proven effective at improving the accuracy of component placement during Total Hip Arthroplasty (THA); however, the material costs, line-of-site issues and potential for significant time increases have limited their widespread use. Objective: The purpose of this study was to investigate the impact of an imageless navigation device on surgical time, when compared with standard mechanical guides. Methods: We retrospectively reviewed prospectively collected data from 61 consecutive primary unilateral THA cases (posterior approach) performed by a single surgeon. Procedural time (incision to closure) for THA performed with (intervention) or without (control) a computer-assisted navigation system was compared. In the intervention group, the additional time associated with the use of the device was recorded. Mean times were compared using independent samples t-tests with statistical significance set a priori at p<0.05. Results: There was no statistically significant difference between procedural time in the intervention and control groups (102.3±28.3 mins vs. 99.1±14.7 mins, p=0.60). The installation and use of the navigation device accounted for an average of 2.9 mins (SD: 1.6) per procedure, of which device-related setup performed prior to skin incision accounted for 1.1 mins (SD: 1.1) and intra-operative tasks accounted for 1.6 mins (SD: 1.2). Conclusion: In this series of 61 consecutive THAs performed by a single surgeon, the set-up and hands-on utilization of a novel surgical navigation tool required an additional 2.9 minutes per case. We suggest that the intraoperative benefits of this novel computer-assisted navigation platform outweigh the minimal operative time spent using this technology.


2018 ◽  
Vol 26 (3) ◽  
pp. 230949901880664 ◽  
Author(s):  
Junya Yoshitani ◽  
Takuya Nakamura ◽  
Yoshinobu Maruhashi ◽  
Noriyuki Hashimoto ◽  
Takeshi Sasagawa ◽  
...  

Purpose: Cup setting with only an alignment guide has been reported to be inaccurate in the lateral decubitus position in total hip arthroplasty (THA). We assessed the accuracy of cup positioning using only the alignment guide technique via a modified Watson Jones approach in the lateral decubitus position. Methods: Two hundred hips of 189 patients underwent THA from October 2014 to September 2016 via a modified Watson Jones approach. In the final sample, 181 hips of 171 patients (35 males, 136 females) were included in this investigation. The alignment of the cup was evaluated by an anteroposterior radiograph of the pelvis 1 week after surgery. Measurements were divided into safe zone determined by Callanan and Lewinnek. Results: There were 168 (92.8%) acetabular cups that were placed within the safe zone for both inclination and anteversion based on the safe zones defined by Lewinnek, and 134 (74%) acetabular cups that were placed within the safe zone defined by Callanan. Multiple logistic analysis showed that the laterality and the addition of the confirmation method were indicators for malpositioning of combined inclination and anteversion. Conclusion: Our data suggested that even if special tools were not used in the lateral decubitus position, using only the alignment guide enabled cup positioning to be achieved with 92.8% accuracy in the Lewinnek safe zone and 74% accuracy in the Callanan safe zone. Multiple logistic analysis showed that the laterality and the addition of a confirmation alignment guide influenced the accuracy of cup positioning.


2020 ◽  
Vol 9 (6) ◽  
pp. 1620
Author(s):  
Richard Lass ◽  
Boris Olischar ◽  
Bernd Kubista ◽  
Thomas Waldhoer ◽  
Alexander Giurea ◽  
...  

The purpose of this study is to compare computer-assisted to manual implantation-techniques in total hip arthroplasty (THA) and to find out if the computer-assisted surgery is able to improve the clinical and functional results and reduce the dislocation rate in short-terms after THA. We performed a concise minimum 2-year follow-up of the patient cohort of a prospective randomized study published in 2014 and evaluated if the higher implantation accuracy in the navigated group can be seen as an important determinant of success in total hip arthroplasty. Although a significant difference was found in mean postoperative acetabular component anteversion and in the outliers regarding inclination and anteversion (p < 0.05) between the computer-assisted and the manual-placed group, we could not find significant differences regarding clinical outcome or revision rates at 2-years follow-up. The implantation accuracy in the navigated group can be regarded as an important determinant of success in THA, although no significant differences in clinical outcome could be detected at short-term follow-up. Therefore, further long-term follow-up of our patient group is needed.


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

2015 ◽  
Vol 30 (12) ◽  
pp. 2204-2207 ◽  
Author(s):  
Asheesh Gupta ◽  
John M. Redmond ◽  
Jon E. Hammarstedt ◽  
Alexandra E. Petrakos ◽  
S. Pavan Vemula ◽  
...  

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