scholarly journals Trends In Cup Position Utilizing Computer-Assisted Navigation During Total Hip Arthroplasty

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.

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.


2002 ◽  
Vol 43 (5) ◽  
pp. 517-527 ◽  
Author(s):  
L. Olivecrona ◽  
J. Crafoord ◽  
H. Olivecrona ◽  
M. E. Noz ◽  
G. Q. Maguire ◽  
...  

Purpose: To develop a non-invasive method for detection of acetabular cup migration after total hip arthroplasty (THA) with a higher degree of accuracy than routine plain radiography. Material and Methods: Two CT examinations, 10 min apart, were obtained from each of 10 patients that had undergone THA. Using an in-house developed semiautomated program for volume merging, the pelves in the two examinations were fused and the acetabular cup was visually and numerically evaluated to test the method's accuracy in detecting migration. Results: In the visual evaluation of the best match a 1-mm translation of the cup was detectable. The numerical evaluation, comparing landmarks placed in the images of the acetabular cup and the head of the femur component in the two examinations, showed the mean difference in orientation of acetabular axes to be 2.5°, the mean distance between centre of cup face to be 2.5 mm and the mean distance between centre of the head of the prosthetic femoral component to be 1 mm. Conclusion: This method has a significantly higher accuracy than routine plain radiography in detecting acetabular cup migration and could be used in clinical practice. It gives both a visual and a numerical correlate to migration.


2016 ◽  
Vol 88 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Kurt G Seagrave ◽  
Anders Troelsen ◽  
Henrik Malchau ◽  
Henrik Husted ◽  
Kirill Gromov

2020 ◽  
Author(s):  
Sang Min Lee ◽  
Kuen Tak Suh ◽  
Won Chul Shin ◽  
Young Kwang Oh ◽  
Seung Hun Woo

Abstract Background Although hip arthroplasty has become increasingly common, its radiological and clinical outcomes in chronic renal failure patients remain unclear. This study analyzed the outcomes of hip arthroplasty in patients with chronic renal failure undergoing dialysis. Methods Of 2,364 hips undergoing total hip arthroplasty or bipolar hemiarthroplasty between January 2003 and December 2017, data pertaining of 37 hips of patients with chronic renal failure undergoing dialysis (16 men, 21 women) were retrospectively examined. We analyzed the radiological and clinical outcomes of hip arthroplasty, as well as the occurrence of local and general complications (particularly the time of their occurrence) during follow-up and their association with dialysis duration. Results The mean patient age was 60.6 ± 13.5 years, and the mean follow-up duration was 36.6 ± 27.2 months. The mean T-value indicating bone mineral density was -2.62 ± 1.15, with osteoporosis noted in 20 cases. Except for 1 case with infection-induced change in acetabular cup tilt, all cases of total hip arthroplasty with cementless acetabular cup implant exhibited excellent radiographic outcomes. The cementless proximally coated femoral stem was used in all 25 cases of total hip arthroplasty and 7 out of 12 cases of bipolar hemiarthroplasty. Changes in the alignment of femoral stems, subsidence, osteolysis, and loosening were not observed. On clinical assessment, 33 patients received an “excellent” or “good” Harris hip score. Within 1 year postoperatively, complications developed in 18 patients, and some patients exhibited more than 1 complication. More than 1 year after surgery, general complications developed in 12 patients; however, no patient experienced local complications.Conclusions Hip arthroplasty in chronic renal failure patients on dialysis showed excellent radiological and satisfactory clinical outcomes; however, it may be associated with various postoperative complications. Therefore, meticulous preoperative treatment planning and overall postoperative management are required to reduce the risk of complications.


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.


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.


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