Acoustic-Based Spatio-Temporal Learning for Press-Fit Evaluation of Femoral Stem Implants

2021 ◽  
pp. 447-456
Author(s):  
Matthias Seibold ◽  
Armando Hoch ◽  
Daniel Suter ◽  
Mazda Farshad ◽  
Patrick O. Zingg ◽  
...  
Keyword(s):  
Femoral Stem ◽  
Press Fit ◽  
Spatio Temporal ◽  
Temporal Learning

scholarly journals Spatio-Temporal Learning of Basketball Offensive Strategies

2015 ◽  
Author(s):  
Ching-Hang Chen ◽  
Tyng-Luh Liu ◽  
Yu-Shuen Wang ◽  
Hung-Kuo Chu ◽  
Nick C. Tang ◽  
...  
Keyword(s):  
Spatio Temporal ◽  
Temporal Learning ◽  
Offensive Strategies

The Shape and Size of the Frmoral Canal in the Korean for Press Fit Femoral Stem

1994 ◽  
Vol 29 (5) ◽  
pp. 1475
Author(s):  
Jin Hwan Ahn ◽  
Dae Kyung Bae ◽  
Myung Chul Yoo ◽  
Ki Tack Kim ◽  
Kyung Nam Ryu ◽  
...  
Keyword(s):  
Femoral Stem ◽  
Press Fit ◽  
Shape And Size

scholarly journals Effect of altered proximal femoral geometry on predicting femoral stem anteversion in patients with developmental dysplasia of the hip

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Chenhui Huang ◽  
Haitao Tan ◽  
Willem Alexander Kernkamp ◽  
Rongshan Cheng ◽  
Junjie Liang ◽  
...  
Keyword(s):  
Femoral Stem ◽  
Femoral Anteversion ◽  
Developmental Dysplasia ◽  
Prediction Errors ◽  
Strong Positive Correlation ◽  
Positive Correlation ◽  
Press Fit ◽  
Preoperative Ct ◽  
Dysplasia Of The Hip ◽  
Anatomical Parameters

Abstract Background The deformity of the proximal femur and acetabular in patients with developmental dysplasia of the hip (DDH) renders an intraoperative decision for ideal component placement challenging. We hypothesized that the altered morphology of calcar femorale (CF) in DDH patients changed the fixation mechanism of the cementless metaphyseal-filling stem and aimed to predict stem anteversion using proximal femoral anatomical parameters from preoperative CT. Methods Preoperative and postoperative CT scans of 34 DDHs with a metaphyseal-filling stem in THA were retrospectively analyzed. Proximal femoral anatomical parameters, including the femoral anteversion (FA) and the CF angles at the low femoral neck (LFN) and the center of the lesser trochanter (CLT) levels (FA-LFN, FA-CLT, CF-LFN, and CF-CLT) were measured. The dysplastic hips were divided into the CF group (n = 21) and the non-CF group (n = 13) according to the presence of the CF-LFN. The association between the anatomical parameters and the postoperative stem anteversion was statistically analyzed, and the predicted stem anteversion was compared with postoperative stem anteversion. Results In the CF group, the combination of the CF-LFN and FA-CLT exhibited a strong positive correlation (R = 0.870, p < 0.001) with the postoperative stem anteversion. In the non-CF group, only the FA-LFN had a strong positive correlation (R = 0.864, p < 0.001). Average prediction errors were 5.9° and 6.4° in the CF and non-CF groups. Conclusions The presence of CF-LFN is related to the press-fit mechanism of the metaphyseal-filling stem, and the preoperative measurements from CT images can be employed as a tool to predict postoperative stem anteversion in DDH patients.

Failure of an Uncemented Press-Fit Acetabular Cup in Primary Total Hip Arthroplasty

2002 ◽  
Vol 12 (4) ◽  
pp. 371-377 ◽  
Author(s):  
N. Rama Mohan ◽  
P. Grigoris ◽  
D.L. Hamblen
Keyword(s):  
Femoral Stem ◽  
Acetabular Cup ◽  
Total Hip ◽  
Press Fit ◽  
Total Hip Replacements ◽  
Locking Mechanism ◽  
Hip Replacements ◽  
The Mean ◽  
Open Position ◽  
Primary Total Hip Arthroplasty

We reviewed fifteen primary total hip replacements performed using the uncemented, non-porous coated press-fit AcSys Shearer Cup. A modular titanium straight femoral stem with a 32mm head was used in all cases. The mean age of the group containing five males and 10 females was 66 years. Eight cups have been revised for aseptic loosening at a mean of seven years and the remaining four cups are radiologically loose. At revision surgery none of the cups showed any evidence of bony ingrowth. Our 10-year results with this cup indicate an unacceptably high failure rate of 80%. Absence of bony ingrowth and the lack of a secure locking mechanism between the polyethylene liner and the metal shell are the most important causes of failure. The use of a 32mm diameter head and implantation of the cup in an open position contributed to this failure. Even though this cup is no longer manufactured, our experience suggests that all non-porous coated cups should be closely followed up.

scholarly journals Adversarial Spatio-Temporal Learning for Video Deblurring

2019 ◽  
Vol 28 (1) ◽  
pp. 291-301 ◽  
Author(s):  
Kaihao Zhang ◽  
Wenhan Luo ◽  
Yiran Zhong ◽  
Lin Ma ◽  
Wei Liu ◽  
...  
Keyword(s):  
Spatio Temporal ◽  
Temporal Learning

Immediate Changes of Bone Density Caused by the Implantation of a Femoral Stem - A Dexa Study

2011 ◽  
Vol 21 (6) ◽  
pp. 706-712 ◽  
Author(s):  
Ulf G. Leichtle ◽  
Jeremi Leasure ◽  
Franz Martini ◽  
Carmen I. Leichtle
Keyword(s):  
Bone Density ◽  
Bone Loss ◽  
Femoral Stem ◽  
Periprosthetic Bone ◽  
Experimental Conditions ◽  
Press Fit ◽  
Custom Made ◽  
Femoral Stems ◽  
Cementless Prosthesis ◽  
Post Implantation

Considerable immediate periprosthetic bone density changes after implantation of femoral stems have been observed comparing DEXA measurements taken pre- and post-operatively. This is important in relation to the interpretation of DEXA studies. We analysed these density changes under standardised experimental conditions. Five human femora were implanted with a custom made femoral stem and ten femora with a standard cementless prosthesis. Densitometry was performed at various stages of implantation. Following rasping only slight density changes were noted (–2.7% to +0.7%). Comparing post-implantation and pre-operative measurements, all custom made stems with a proximal press-fit demonstrated clear increases in proximal periprosthetic bone density of +11% and +14%. In contrast, the standard prosthesis with a distal press-fit showed a loss of –5% and –2% in the proximal zones. Measurements following removal of the implants demonstrated hardly any density changes (0% to –4%) compared to the pre-operative measurements. We concluded that compacting of trabecular bone or bone loss due to rasping are not the main causes of density changes. Substantial measuring errors exist. For examination of periprosthetic bone density changes, pre-operative initial measurements should not be used as a baseline for comparison. Studies should commence with an immediate postoperative measurement.

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