Improving the Fit of Press-Fit Hip Stems

Robertson, Douglas D.; Walker, Peter S.; Hirano, Sandra K.; Zhou, Xuan; Granholm, John W.; Poss, Robert

doi:10.1097/00003086-198803000-00020

Cited by 38 publications

(12 citation statements)

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“…Another technique used now to improve the intimate contact between the prosthesis and bone is called 'press-fit', in which the femoral instrumentation used to achieve an intimate fit between bone and prosthesis can be undersized compared with the real prosthesis depending on the hip system used (Amstutz et al, 1991;Otani et al, 1995;Robertson et al, 1988;Robinson and Clark, 1996). This technique appears to help bony ingrowth into the prosthesis and is accepted by many orthopaedic surgeons.…”

Section: Discussionmentioning

confidence: 99%

The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty

Hahne

Hassenpflug

2004

J. Zheijang Univ.-Sci.

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Abstract:Objective: To observe the accuracy of femoral preparation and the position of the cementless prosthesis in femoral cavity, and to compare the results between the computer-assisted surgical group (CASPAR) and the conventional group. Methods: Ten femoral components were implanted either manually or by CASPAR in cadaver femurs. The specimens were cut to 3 mm thick slices. Microradiograms of every slice were sent to a computer for analysis with special software (IDL). The gaps and the medullary cavities between component and bone, the direct bone contact area of the implant surface, the gap width and the percentage of gap and bone contact area were measured in every slice. Results: In the proximal implant coated with HA of the CASPAR group, the average percentage of bone contact reached 93.2% (ranging from 87.6% to 99.7%); the average gap percentage was 2.9% (ranging from 0.3% to 7.8%); the maximum gap width was 0.81 mm and the average gap width was only 0.20 mm. While in the conventional group, the average percentage of bone contact reached 60.1% (ranging from 49.2% to 70.4%); the average gap percentage was 32.8% (ranging from 25.1% to 39.9%); the maximum gap width was 2.97 mm and the average gap width was 0.77 mm. The average gap around the implant in the CASPAR group was only 9% of that in the manual group; the maximum and average gap widths were only about 26% of those in the manual group. On the other hand, the CASPAR group showed 33% higher bone contact than the manual group. Conclusion: With the use of robotics-assisted system, significant progress can be achieved for femoral preparation in total hip arthroplasty.

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Section: Discussionmentioning

confidence: 99%

The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty

Hahne

Hassenpflug

2004

J. Zheijang Univ.-Sci.

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“…9,2~ To improve the steminner cortex fit in these patients will require one of the following: (1) the use of an individual stem, 1,18,24,25,26 (2) the use of a modular system, 5,14,29 or (3) the development of a new stem design. 19,2~176…”

Section: Choice Of Cementless Stems For Secondary Osteoarthritismentioning

confidence: 99%

Fit and fill analysis of a newly designed femoral stem in cementless total hip arthroplasty for patients with secondary osteoarthritis*

Imura

Omori

et al. 1997

Journal of Orthopaedic Science

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“…Predecessors of this method have been primarily based upon 'fit and fill' strategies that sought to optimise variables for position, orientation and shape of the component to achieve maximum cavity fill and contact with an extracted description of the endosteum. ROBERTSON et al (1989) developed a model for determining the best 3D prosthesis shape to maximise contact between the femoral component and inner cortical bone, while preserving contact in areas of load transfer, simultaneously confirming that the component was surgically insertable. The optimisation started with an implant that matched the exact canal shape and was modified as it was extracted from the canal, giving priority to maintaining stem areas for contact at the prioritised regions.…”

Section: Introductionmentioning

confidence: 99%

Periprosthetic modelling of femoral component fit using computed tomography data for total hip arthroplasty: A feasibility study

Hauser-Kara

Bartel

2002

Med. Biol. Eng. Comput.

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The aim of the work was to create a new three-dimensional periprosthetic multi-criteria optimisation technique to identify the best six degrees of freedom transform to position a porous-coated anatomic cementless femoral component for three factors, including: first, maximisation of the degree of contact achieved between designated bone ingrowth surfaces and the periprosthetic bone; secondly, minimisation of the bone mass to be removed to accommodate the component and thirdly, the extreme constraint of the component to be positioned so that it does not project beyond the periosteum. Discrete integrals were computed over regions of interest derived from the polyhedral component mesh in transaxial CT scan planes, using a polygon scan-conversion algorithm. A new biomedical imaging volume rendering technique utilising dynamic virtual textures was developed to visualise the design trade-offs. Pareto-optima were identified for four femora that matched an average-sized component. The non-linear, multi-modal fit metric was quadratic near minima, with a narrow trough of equivalent fit values within 3mm of translation and 3 degrees of rotation with respect to the canal axis, and possessed a dependence most pronounced for distal-directed insertion against varus/valgus rotation. The study gives previously unavailable data on the three-dimensional femoral component fit and is the first report that demonstrates that fitting the implant using several design criteria in a multi-criteria optimisation scheme is feasible.

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Improving the Fit of Press-Fit Hip Stems

Cited by 38 publications

References 0 publications

The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty

The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty

Fit and fill analysis of a newly designed femoral stem in cementless total hip arthroplasty for patients with secondary osteoarthritis*

Periprosthetic modelling of femoral component fit using computed tomography data for total hip arthroplasty: A feasibility study

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