The effect of porous coating and loading conditions on total hip femoral stem stability

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.

Download Full-text

The impact of reducing the femoral stem length in total hip arthroplasty during gait

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-021-03852-w ◽

2021 ◽

Author(s):

Anatole Vilhelm Wiik ◽

Adeel Aqil ◽

Bilal Al-Obaidi ◽

Mads Brevadt ◽

Justin Peter Cobb

Keyword(s):

Total Hip Arthroplasty ◽

Gait Analysis ◽

Hip Arthroplasty ◽

Femoral Stem ◽

Short Stem ◽

Stem Length ◽

Practical Consideration ◽

Total Hip ◽

Long Stem ◽

The Impact

Abstract Aim The length of the femoral stem in total hip arthroplasty (THA) is a practical consideration to prevent gait impairment. The aim of this study was to determine if reducing the femoral stem length in THA would lead to impaired gait biomechanics. Methods Patients uniformly with the same brand implant of differing lengths (100 mm vs 140–166 mm) were taken retrospectively from a prospective trial introducing a new short stem. Twelve patients without any other disorder to alter gait besides contralateral differing length stem THA were tested at differing gradients and speed on a validated instrumented treadmill measuring ground reaction forces. An anthropometrically similar group of healthy controls were analysed to compare. Results With the same posterior surgical approach, the offset and length of both hips were reconstructed within 5 mm of each other with an identical mean head size of 36 mm. The short stem was the last procedure for all the hips with gait analysis occurring at a mean of 31 and 79 months postoperatively for the short and long stem THA, respectively. Gait analysis between limbs of both stem lengths demonstrated no statistical difference during any walking condition. In the 90 gait assessments with three loading variables, the short stem was the favoured side 51% of the time compared 49% for the long stem. Conclusion By testing a range of practical walking activities, no lower limb loading differences can be observed by reducing the femoral stem length. A shorter stem demonstrates equivalence in preference during gait when compared to a reputable conventional stem in total hip arthroplasty.

Download Full-text

Long-Term Survivorship of Modular Cementless Femoral Stem in Complex Primary Total Hip Arthroplasty: A Concise Minimum 15 years Follow up Report

The Journal of Arthroplasty ◽

10.1016/j.arth.2021.05.004 ◽

2021 ◽

Author(s):

Rajesh Bawale ◽

Hosam E. Matar ◽

Felipe López Illanes ◽

Hugh U. Cameron

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Femoral Stem ◽

Total Hip ◽

Cementless Femoral Stem ◽

Primary Total Hip Arthroplasty

Download Full-text

Satisfactory Results of the Exeter Revision Femoral Stem Used for Primary Total Hip Arthroplasty

The Journal of Arthroplasty ◽

10.1016/j.arth.2016.07.051 ◽

2017 ◽

Vol 32 (2) ◽

pp. 494-498 ◽

Cited By ~ 1

Author(s):

Nicholas M. Desy ◽

Joshua D. Johnson ◽

Rafael J. Sierra

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Femoral Stem ◽

Total Hip ◽

Primary Total Hip Arthroplasty

Download Full-text

Hydroxyapatite porous coating and the osteointegration of the total hip replacement

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-006-0235-1 ◽

2006 ◽

Vol 127 (2) ◽

pp. 81-89 ◽

Cited By ~ 35

Author(s):

Ivan Landor ◽

Pavel Vavrik ◽

Antonin Sosna ◽

David Jahoda ◽

Henry Hahn ◽

...

Keyword(s):

Total Hip Replacement ◽

Hip Replacement ◽

Porous Coating ◽

Total Hip

Download Full-text

Variation in femoral anteversion in patients requiring total hip replacement

Hip International ◽

10.1177/1120700019848088 ◽

2019 ◽

Vol 30 (3) ◽

pp. 281-287

Author(s):

Jim W Pierrepont ◽

Ed Marel ◽

Jonathan V Baré ◽

Leonard R Walter ◽

Catherine Z Stambouzou ◽

...

Keyword(s):

Total Hip Replacement ◽

Hip Replacement ◽

Femoral Stem ◽

Femoral Anteversion ◽

Patient Specific ◽

3 Dimensional ◽

Total Hip ◽

Age Related ◽

Gender And Age ◽

Implant Alignment

Background: Optimal implant alignment is important for total hip replacement (THR) longevity. Femoral stem anteversion is influenced by the native femoral anteversion. Knowing a patient’s femoral morphology is therefore important when planning optimal THR alignment. We investigated variation in femoral anteversion across a patient population requiring THR. Methods: Preoperatively, native femoral neck anteversion was measured from 3-dimensional CT reconstructions in 1215 patients. Results: The median femoral anteversion was 14.4° (−27.1–54.5°, IQR 7.4–20.9°). There were significant gender differences (males 12.7°, females 16.0°; p < 0.0001). Femoral anteversion in males decreased significantly with increasing age. 14% of patients had extreme anteversion (<0° or >30°). Conclusions: This is the largest series investigating native femoral anteversion in a THR population. Patient variation was large and was similar to published findings of a non-THR population. Gender and age-related differences were observed. Native femoral anteversion is patient-specific and should be considered when planning THR.

Download Full-text