Favorable Midterm Results of Total Hip Arthroplasties with a Lateral Flare Uncemented Stem

Leali, Alex; Fetto, Joseph; Insler, Harvey

doi:10.1097/01.blo.0000214410.60722.b1

Cited by 10 publications

(5 citation statements)

References 34 publications

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“…However, it is difficult to compare the incidence of thigh pain in various studies since the recording has not been standardized.Since no cases of aseptic loosening were recorded at the 7- and 10-year follow-up, it appears that an individual design contributes to safe fixation of the stem. Similar findings have been reported from other groups using custom stems (Wettstein et al 2005, Leali et al 2006, Akbar et al 2009). During the past 10–15 years, however, the rate of aseptic loosening has also been substantially reduced in standard uncemented stems.…”

Section: Discussionsupporting

confidence: 91%

Uncemented custom femoral components in hip arthroplasty

Benum¹,

Aamodt²

2010

Acta Orthopaedica

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Background and purposeWe have developed an individually designed, uncemented femoral component for achievement of improved strain distribution and fixation to the bone, to make uncemented stems more applicable in femurs of abnormal size and shape, and to improve the joint mechanics. Here we describe the design of the implant and present the results of a prospective clinical study with at least 7 years of follow-up.Patients and methodsThe prostheses are produced by CAD-CAM technique. The design of the stem is based on CT information, and the neck design is based on the surgeon's planning of the center of rotation, femoral head offset, and leg length correction. The first-generation stem produced before 2001 had a proximal HA coating and a sand-blasted distal part that was down-scaled to avoid contact with compact bone. The second-generation stem had a porous coating beneath the HA layer and the distal part of the stem was polished.The implant was used in 762 hips (614 patients) from 1995 until 2009. 191 of these hips were followed for 7 years and 83 others were followed for 10 years, and these hips are included in the present study. Mean age at surgery was 48 (20–65) years. Congenital dysplasia of the hip was the reason for osteoarthritis in 46% and 57% of the hips in respective groups. Merle d'Aubigné score was recorded in 152 and 75 hips in the two groups. Prostheses followed for 10 years, and almost all in the 7-year group, were first-generation stems.ResultsThe 7- and 10-year cumulative revision rates were 1.1% and 2.4%, respectively, with stem revision for any reason as endpoint. The clinical results were similar at 7 and 10 years, with Merle d'Aubigné scores of 17. Intraoperative trochanteric fissures occurred in 2 of the 191 operations (1.0%); both healed after wiring. In hips followed for 7 years, 2 periprosthetic fractures occurred; exchange of the stem was necessary in both. One additional fracture occurred between 7 and 10 years, and it was treated successfully with osteosynthesis. The rate of dislocation was 1.6% and 2.4%, respectively. There was no radiographic loosening at follow-up.InterpretationUse of a custom femoral stem gives a reliable fixation and promising medium-term clinical results in femurs of normal and abnormal shape and dimension. The individual design, which enables optimized joint mechanics, gives a low risk of mechanical complications.

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Section: Discussionsupporting

confidence: 91%

Uncemented custom femoral components in hip arthroplasty

Benum¹,

Aamodt²

2010

Acta Orthopaedica

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“…The so-called lateral-flare stem was first custom manufactured beginning in 1992, and its clinical results in the young population are reported elsewhere [16] . The lateral flare stem was made available as a standardized off-theshelf prosthesis in 1997.…”

Section: Introductionmentioning

confidence: 99%

Promising mid-term results of total hip arthroplasties using an uncemented lateral-flare hip prosthesis: a clinical and radiographic study

Leali

Fetto

2007

International Orthopaedics (SICO

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The clinical results after total hip replacements using noncemented stems have shown considerable variability over the years; the design and characteristics of the implant seemed to play a role in explaining this fact. The purpose of this paper is to report the clinical, radiographic and densitometry results of total hip arthroplasties using a stem designed for noncemented implantation and to engage and load the femur proximally. Fifty-eight consecutive patients (62 hips) followed for an average of 4.3 years (range 36-70 months) were clinically and radiographically followed up at three weeks, three months, six months, one year, and yearly thereafter. The average pre-operative Harris hip score was 49 increasing to 98 at the latest follow-up. There were no cases of aseptic or septic loosening. The average subsidence at three years was 0.45 mm (SD±0.36 mm). Radiographically all hips were classified as stable, and evident changes compatible with new bone apposition were observed in 64% of the cases. The extended proximal geometry of the device seems to favour initial and secondary stability as reflected by the low subsidence values over time. The maintenance of periprosthetic bone stock and the absence of stress shielding can be explained by the predominantly proximal loading pattern of the stem.Résumé Les résultats cliniques des arthroplasties totales de hanche utilisant des tiges non-cimentées ont été très variables au cours des années, les caractéristiques de l'implant semblant jouer un rôle important. Le but de ce travail est de rapporter les résultats cliniques et radiologiques d'arthroplasties avec une tige non-cimentée avec appui proximal. 58 patients consécutifs (62 hanches) suivi en moyenne pendant 4,3 ans (36 à 70 mois) étaient étudiés à 3 semaines, 3 mois, 6 mois, 1 an puis tous les ans. Le score moyen de Harris pré-opératoire était de 49, augmentant à 98 au dernier examen. Il n'y avait pas de descellement aseptique ou septique. L'enfoncement moyen à 3 ans était de 0,45 mm (SD 0,36 mm). Radiologiquement toutes les hanches étaient stables et des modifications compatibles avec une ostéoformation était visible dans 64% des cas. La géométrie proximale de la tige semble favoriser la stabilité initiale et secondaire comme le montre le faible enfoncement au fil du temps. La conservation du stock osseux et l'absence de déviation des contraintes peuvent s'expliquer par la mise en charge proximale de la prothès.

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“…Stem designs focused on a lateral enlargement of the proximal portion have been described for human use, and these were created to maximize the proximal adjustment and the filling of the medullary canal, providing greater torsional and axial stability 14 - 17 . This design potentially increases the contact of the implant in the metaphyseal region, thus increasing the cross-sectional diameter of the stem, allowing the stem to have a broader base of metaphysical support 25 , 26 . As a result, there is a better distribution of endosteal compressive forces, which can potentially reduce complications such as subsidence and aseptic loosening 25 .…”

Section: Discussionmentioning

confidence: 99%

“…This design potentially increases the contact of the implant in the metaphyseal region, thus increasing the cross-sectional diameter of the stem, allowing the stem to have a broader base of metaphysical support 25 , 26 . As a result, there is a better distribution of endosteal compressive forces, which can potentially reduce complications such as subsidence and aseptic loosening 25 .…”

Section: Discussionmentioning

confidence: 99%

Biomechanical evaluation of a new femoral stem design for total hip replacement in a canine model

et al. 2021

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Purpose To evaluate the biomechanical properties of a novel total hip replacement femoral stem. Methods Eight pairs of femurs from dog cadavers were used. The femurs were separated into different groups. A novel femoral stem with a convex proximal portion (Stem B) was biomechanically evaluated and compared to awell-known veterinary collared stem (Stem A). Femoral stems were inserted into the contralateral femurs from the same dog, forming 16 constructs. A flexo-compression load was applied on the axial axis of each sample. Maximum strength, deflection, stiffness, and energy absorption were analysed. Results Group B constructs showed significantly higher values (p ? 0.05) for the variables, except stiffness. The mean maximum strength was 1,347 ± 357 N for Group A and 1,805 ± 123 N for Group B (p ? 0.0069). The mean deflection was5.54 ± 2.63 mm for Group A and 10.03 ± 3.99 mm for Group B (p ? 0.0056). For the energy variable, the force was 6,203 ± 3,488 N/mm for Group A and 12,885 ± 5,056 N/mm for Group B (p ? 0.0054). Stem B had greater maximum strength, deflection, and energy. Conclusions The new stem was effective in neutralizing the impact of axial flexion-compression stresses during biomechanical tests in cadaveric models.

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Favorable Midterm Results of Total Hip Arthroplasties with a Lateral Flare Uncemented Stem

Abstract: Therapeutic study, Level IV (case series).

Cited by 10 publications

References 34 publications

Uncemented custom femoral components in hip arthroplasty

Uncemented custom femoral components in hip arthroplasty

Promising mid-term results of total hip arthroplasties using an uncemented lateral-flare hip prosthesis: a clinical and radiographic study

Biomechanical evaluation of a new femoral stem design for total hip replacement in a canine model

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