Femoral anteversion, femoral offset, and abductor lever arm after total hip arthroplasty using a modular femoral neck system

2002 ◽  
Vol 7 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Takashi Sakai ◽  
Nobuhiko Sugano ◽  
Kenji Ohzono ◽  
Takashi Nishii ◽  
Keiji Haraguchi ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Femoral Neck ◽  
Hip Arthroplasty ◽  
Femoral Anteversion ◽  
Femoral Offset ◽  
Total Hip ◽  
Lever Arm ◽  
Abductor Lever Arm ◽  
Modular Femoral Neck System

Optimizing femoral anteversion and offset after total hip arthroplasty, using a modular femoral neck system: an experimental study

2000 ◽  
Vol 5 (5) ◽  
pp. 489-494 ◽  
Author(s):  
Takashi Sakai ◽  
Nobuhiko Sugano ◽  
Takashi Nishii ◽  
Keiji Haraguchi ◽  
Takahiro Ochi ◽  
...  
Keyword(s):  
Experimental Study ◽  
Total Hip Arthroplasty ◽  
Femoral Neck ◽  
Hip Arthroplasty ◽  
Femoral Anteversion ◽  
Total Hip ◽  
Modular Femoral Neck System

scholarly journals Pre- and postoperative offset and femoral neck version measurements and validation using 3D computed tomography in total hip arthroplasty

2020 ◽  
Vol 9 (10) ◽  
pp. 205846012096491
Author(s):  
Mats Geijer ◽  
Sverrir Kiernan ◽  
Martin Sundberg ◽  
Gunnar Flivik
Keyword(s):  
Total Hip Arthroplasty ◽  
Femoral Neck ◽  
Hip Arthroplasty ◽  
Intraclass Correlation ◽  
Hip Osteoarthritis ◽  
Data Sets ◽  
Femoral Offset ◽  
Total Hip ◽  
Femoral Neck Anteversion ◽  
Before And After

Background Restoration of a correct biomechanical situation after total hip arthroplasty is important. Purpose To evaluate proximal femoral symmetry of acetabular and femoral offset and femoral neck anteversion pre- and postoperatively in hip arthroplasty by semi-automated 3D-CT and to validate the software measurements by inter- and intraobserver agreement calculations. Material and Methods In low-dose CT on 71 patients before and after unilateral total hip arthroplasty, two observers used a digital 3D templating software to measure acetabular offset, true and functional femoral offset, and femoral neck anteversion. Observer agreements were calculated using intraclass correlation. Hip measurements were compared in each patient and between pre- and postoperative measurements. Results Preoperatively, acetabular offset (2.4 mm), true (2.2 mm), and functional global offset (2.7 mm) were significantly larger on the osteoarthritic side without side-to-side differences for true and functional femoral offset or femoral neck anteversion. Postoperatively, acetabular offset was significantly smaller on the operated side (2.1 mm) with a concomitantly increased true (2.5 mm) and functional femoral offset (1.5 mm), resulting in symmetric true and functional global offsets. There were no differences in postoperative femoral neck anteversion. Inter- and intraobserver agreements were near-perfect, ranging between 0.92 and 0.98 with narrow confidence intervals (0.77–0.98 to 0.94–0.99). Conclusion Acetabular and concomitantly global offset are generally increased in hip osteoarthritis. Postoperative acetabular offset was reduced, and femoral offset increased to maintain global offset. 3D measurements were reproducible with near-perfect observer agreements. 3D data sets should be used for pre- and postoperative measurements in hip arthroplasty.

Contact force path in total hip arthroplasty: effect of cup medialisation in a whole-body simulation

2020 ◽  
pp. 112070002091732
Author(s):  
Enrico De Pieri ◽  
Federica Atzori ◽  
Stephen J Ferguson ◽  
Sebastian Dendorfer ◽  
Michael Leunig ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Contact Force ◽  
Hip Arthroplasty ◽  
Whole Body ◽  
Anatomical Reconstruction ◽  
Femoral Offset ◽  
Total Hip ◽  
Lever Arm ◽  
Press Fit ◽  
Force Magnitude

Background: Cup medialisation down to the true acetabular floor in total hip arthroplasty with a compensatory femoral offset increase seems to be mechanically advantageous for the abductor muscles due to the relocation of the lever arms (body weight lever arm decreased, abductor lever arm increased). However, limited information is currently available about the effects of this reconstruction type at the head cup interface, compared to an anatomical reconstruction that maintains the natural lever arms. Through a whole-body simulation analysis, we compared medialised versus anatomical reconstruction in THA to analyse the effects on: (1) contact force magnitude at the head cup interface; (2) contact force path in the cup; and (3) abductor activity. Methods: Musculoskeletal simulations were performed to calculate the above-mentioned parameters using inverse dynamics analysis. The differences between the virtually implanted THAs were calculated to compare the medialised versus anatomical reconstruction. Results: Cup medialisation with compensatory femoral offset increase led to: (1) a reduction in contact force magnitude at the head cup interface up to 6.6%; (2) a similar contact force path in the cup in terms of sliding distance and aspect ratio; and (3) a reduction in abductor activity up to 17.2% (gluteus medius). Conclusions: In our opinion, these potential biomechanical gains do not generally justify a fully medialised reconstruction, especially in younger patients that are more likely to undergo revision surgery in their lifetime. Cup medialisation should be performed until sufficient press fit and bony coverage of a properly sized and oriented cup can be achieved.

scholarly journals Value of 3D Preoperative Planning for Primary Total Hip Arthroplasty Based on Biplanar Weightbearing Radiographs

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Y. Knafo ◽  
F. Houfani ◽  
B. Zaharia ◽  
F. Egrise ◽  
I. Clerc-Urmès ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Preoperative Planning ◽  
Femoral Stem ◽  
Leg Length ◽  
Femoral Offset ◽  
Postoperative Result ◽  
Total Hip ◽  
Planning Software ◽  
Navigated Surgery

Two-dimensional (2D) planning on standard radiographs for total hip arthroplasty may not be sufficiently accurate to predict implant sizing or restore leg length and femoral offset, whereas 3D planning avoids magnification and projection errors. Furthermore, weightbearing measures are not available with computed tomography (CT) and leg length and offset are rarely checked postoperatively using any imaging modality. Navigation can usually achieve a surgical plan precisely, but the choice of that plan remains key, which is best guided by preoperative planning. The study objectives were therefore to (1) evaluate the accuracy of stem/cup size prediction using dedicated 3D planning software based on biplanar radiographic imaging under weightbearing and (2) compare the preplanned leg length and femoral offset with the postoperative result. This single-centre, single-surgeon prospective study consisted of a cohort of 33 patients operated on over 24 months. The routine clinical workflow consisted of preoperative biplanar weightbearing imaging, 3D surgical planning, navigated surgery to execute the plan, and postoperative biplanar imaging to verify the radiological outcomes in 3D weightbearing. 3D planning was performed with the dedicated hipEOS® planning software to determine stem and cup size and position, plus 3D anatomical and functional parameters, in particular variations in leg length and femoral offset. Component size planning accuracy was 94% (31/33) within one size for the femoral stem and 100% (33/33) within one size for the acetabular cup. There were no significant differences between planned versus implanted femoral stem size or planned versus measured changes in leg length or offset. Cup size did differ significantly, tending towards implanting one size larger when there was a difference. Biplanar radiographs plus hipEOS planning software showed good reliability for predicting implant size, leg length, and femoral offset and postoperatively provided a check on the navigated surgery. Compared to previous studies, the predictive results were better than 2D planning on conventional radiography and equal to 3D planning on CT images, with lower radiation dose, and in the weightbearing position.

Combination of CRP with NLR is a sensitive tool for screening fixation-related infection in patients undergoing conversion total hip arthroplasty after failed internal fixation for femoral neck fracture

2021 ◽  
pp. 1-7
Author(s):  
Hong Xu ◽  
Jin-Wei Xie ◽  
Li Liu ◽  
Duan Wang ◽  
Ze-Yu Huang ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Femoral Neck ◽  
Internal Fixation ◽  
Femoral Neck Fracture ◽  
Sensitivity And Specificity ◽  
Hip Arthroplasty ◽  
Lymphocyte Ratio ◽  
Total Hip ◽  
Sensitive Tool ◽  
Neck Fracture

Aims Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture. Methods We retrospectively included 340 patients who underwent conversion THA after internal fixation for femoral neck fracture from January 2008 to September 2020. Those patients constituted two groups: noninfected patients and patients diagnosed with FRI according to the 2013 International Consensus Meeting Criteria. Receiver operating characteristic (ROC) curves were used to determine maximum sensitivity and specificity of these two preoperative ratios. The diagnostic performance of the two ratios combined with preoperative CRP or ESR was also evaluated. Results The numbers of patients with and without FRI were 19 (5.6%) and 321 (94.4%), respectively. Areas under the ROC curve for diagnosing FRI were 0.763 for MLR, 0.686 for NLR, 0.905 for CRP, and 0.769 for ESR. Based on the Youden index, the optimal predictive cutoffs were 0.25 for MLR and 2.38 for NLR. Sensitivity and specificity were 78.9% and 71.0% for MLR, and 78.9% and 56.4% for NLR, respectively. The combination of CRP with MLR showed a sensitivity of 84.2% and specificity of 94.6%, while the corresponding values for the combination of CRP with NLR were 89.5% and 91.5%, respectively. Conclusion The presence of preoperative FRI among patients undergoing conversion THA after internal fixation for femoral neck fracture should be determined. The combination of preoperative CRP with NLR is sensitive tool for screening FRI in those patients.

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