Uncemented short stems in primary total hip arthroplasty: The state of the art

in EFORT Open Reviews
Authors:
Mattia Loppini Department of Biomedical Sciences, Humanitas University, Italy; Hip Diseases and Joint Replacement Surgery Unit, Humanitas Clinical and Research Center, Italy

Search for other papers by Mattia Loppini in
Current site
Google Scholar
PubMed
Close
and
Guido Grappiolo Hip Diseases and Joint Replacement Surgery Unit, Humanitas Clinical and Research Center, Italy

Search for other papers by Guido Grappiolo in
Current site
Google Scholar
PubMed
Close

M. Loppini, Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini snc, 20090 Pieve Emanuele, Milan, Italy. Email: mattia.loppini@hunimed.eu
Open access

  • Over the last two decades, several conservative femoral prostheses have been designed. The goals of conservative stems include: the spearing of the trochanteric bone stock; a more physiological loading in the proximal femur reducing the risk of stress shielding; and to avoid a long stem into the diaphysis preventing impingement with the femoral cortex and thigh pain.

  • All stems designed to be less invasive than conventional uncemented stems are commonly named ‘short stems’. However, this term is misleading because it refers to a heterogeneous group of stems deeply different in terms of design, biomechanics and bearing. In the short-term follow-up, all conservative stems provided excellent survivorship. However, variable rates of complications were reported, including stem malalignment, incorrect stem sizing and intra-operative fracture.

  • Radiostereometric analysis (RSA) studies demonstrated that some conservative stems were affected by an early slight migration and rotation within the first months after surgery, followed by a secondary stable fixation. Dual-energy x-ray absorptiometry (DEXA) studies demonstrated an implant-specific pattern of bone remodelling.

  • Although the vast majority of stems demonstrated a good osseointegration, some prostheses transferred loads particularly to the lateral and distal-medial regions, favouring proximal stress shielding and bone atrophy in the great trochanter and calcar regions.

Cite this article: EFORT Open Rev 2018;3:149-159. DOI: 10.1302/2058-5241.3.170052

Abstract

  • Over the last two decades, several conservative femoral prostheses have been designed. The goals of conservative stems include: the spearing of the trochanteric bone stock; a more physiological loading in the proximal femur reducing the risk of stress shielding; and to avoid a long stem into the diaphysis preventing impingement with the femoral cortex and thigh pain.

  • All stems designed to be less invasive than conventional uncemented stems are commonly named ‘short stems’. However, this term is misleading because it refers to a heterogeneous group of stems deeply different in terms of design, biomechanics and bearing. In the short-term follow-up, all conservative stems provided excellent survivorship. However, variable rates of complications were reported, including stem malalignment, incorrect stem sizing and intra-operative fracture.

  • Radiostereometric analysis (RSA) studies demonstrated that some conservative stems were affected by an early slight migration and rotation within the first months after surgery, followed by a secondary stable fixation. Dual-energy x-ray absorptiometry (DEXA) studies demonstrated an implant-specific pattern of bone remodelling.

  • Although the vast majority of stems demonstrated a good osseointegration, some prostheses transferred loads particularly to the lateral and distal-medial regions, favouring proximal stress shielding and bone atrophy in the great trochanter and calcar regions.

Cite this article: EFORT Open Rev 2018;3:149-159. DOI: 10.1302/2058-5241.3.170052

Introduction

In many countries, such as in North America, Australia and the southern region of Europe, cementless fixation represents the most common technique used in total hip arthroplasty (THA). 1,2 Although some authors have advocated the superiority of cemented fixation over uncemented fixation, 3,4 conventional uncemented stems have shown excellent results in the long term. 5,6 However, they could be associated with reduction of the trochanteric bone stock and thigh pain due to the invasion of the femoral shaft.

Over the last two decades, several conservative femoral prostheses have been designed and some authors advocated their use, particularly in young patients with high-activity recreational interests. 7,8 The goals of conservative stems include: the spearing of the trochanteric bone stock; a more physiological loading in the proximal femur reducing the risk of stress shielding; and to avoid a long stem into the diaphysis preventing impingement with the femoral cortex and thigh pain. 9,10

All stems designed to be less invasive than conventional uncemented stems are commonly named ‘short stems’. However, this term is misleading because it refers to a heterogeneous group of stems deeply different in terms of design, biomechanics, principles of fixation and bearing. In this respect, several classification systems for femoral stems have been developed, taking into account features such as length of the stem, location of loading, osteotomy level for the neck resection and implant fixation principles (Table 1). 1115 McTighe et al 11 proposed the term ‘short’ for stems that do not extend below the metaphyseal region of the proximal femur. In this respect, they proposed three types of stems: head stabilized (resurfacing); neck stabilized; and metaphyseal stabilized. Recently, Khanuja et al 12 classified short stems according to fixation principles and location of proximal loading. The authors distinguished four categories: femoral neck fixation; calcar loading; lateral flare and calcar loading; and shortened tapered stems. In this classification system, resurfacing was not included.

Table 1.

Classification systems for femoral stems

Authors (year) Classes Description Rationale
McTighe et al 11 (2013) • Head stabilized • Resurfacing. Assessment of length and method of achieving primary stability of the stem.
• Neck stabilized • Short curved neck-sparing stems, and standard-length stems preserving femoral neck, but engaging the neck, metaphysis and diaphysis.
• Metaphyseal stabilized • Short metaphyseal stems including anatomical, straight and tapered designs.
• Conventional (metaphyseal/diaphyseal) stabilized • Conventional stems engaging both metaphysis and diaphysis.
Feyen and Shimmin 14 (2014) • Type I • Resurfacing. Assessment of the osteotomy level for the neck resection and implant fixation principles.
• Type II • Mid-head resection stems.
• Type III • Short stems with subcapital (IIIA) or standard (IIIB) osteotomy.
• Type IV • Traditional stems.
• Type V • Diaphyseal fixation stems.
Van Oldenrijk et al 15 (2014) • Collum • Conical or cylindrical ultra-short stems, with complete anchorage in the femoral neck. Assessment of the osteotomy level for the neck resection and implant fixation principles.
• Partial collum • Partial femoral neck-sparing curved designs.
• Trochanter-sparing • Trochanter-sparing but not neck-sparing, and shortened tapered stems.
Khanuja et al 12 (2014) • Type I • Femoral neck fixation stems (from IA to IC according to the stem geometry). Assessment of location of loading and implant fixation principles.
• Type II • Calcar loading stems (from IIA to IID according to the stem geometry).
• Type III • Calcar loading with lateral flare stems.
• Type IV • Shortened tapered stems.
Falez et al 13 (2015) • Collum • Conical or cylindrical ultra-short stems, with complete anchorage in the femoral neck. Assessment of the osteotomy level for the neck resection and implant fixation principles.
• Partial collum • Partial femoral neck-sparing curved designs.
• Trochanter-sparing • Trochanter-sparing but not neck-sparing, and shortened tapered stems.
• Trochanter-harming • Short stems interrupting the circumferential integrity of the femoral neck section and violating trochanteric region.

The purpose of the present paper is to provide an overview of the most common conservative stems, describing their features and analysing their clinical and radiological results.

Inclusion criteria and study collection

A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar databases was performed, using various combinations of the following keywords: ‘short stem’; ‘conservative stem’; ‘metaphyseal’; ‘neck-sparing’; ‘trochanter-sparing’; ‘uncemented’; and ‘total hip arthroplasty’.

All peer-reviewed journals were considered and all articles reporting outcomes of primary total hip arthroplasty performed with short stems were analysed. A cross-reference research of the selected articles was also performed to obtain other relevant articles for the study. Finally, a search of every prosthesis according to the name of the implant was performed.

In the present review, we did not include all the conservative stems available for clinical practice. We defined as ‘short’ all the stems having fixation in the neck and engaging the metaphysis and diaphysis, or in the metaphysis with or without engagement of the proximal part of the diaphysis. Studies investigating hip resurfacing or femoral neck implants and stems with extramedullary anchorage systems such as the thrust-plate prosthesis were excluded.

To be included in this review, a study had to be published in a peer-reviewed journal, to investigate a short uncemented stem, to provide survivorship of the implant and report complications or revision rates, and to have a minimum follow-up of one year. Radiostereometric analysis (RSA) and dual-energy x-ray absorptiometry (DEXA) studies performed on short stems were also included.

Stem features and outcomes

Collum femoris preserving (CFP)

The CFP (Waldemar Link) is an uncemented neck-retaining stem (Fig. 1). It is made of a Tilastan® alloy with a 70-μm microporous surface provided with a 20-μm hydroxyapatite coating, but the distal third is smooth. The primary stability of the stem is achieved by the contact with the calcar and the lateral femoral cortex, and longitudinal ribs enhance the rotational stability.

Fig. 1
Fig. 1

CFP stem at ten years of follow-up.

Citation: EFORT Open Reviews 3, 5; 10.1302/2058-5241.3.170052

The CFP stem demonstrated a mean survivorship of 98.8% (95.8% to 100%) with aseptic loosening as the endpoint, at a mean follow-up of seven years (2 to 17) in 1657 hips. 1632 The mean Harris hip score (HHS) was 89 points (49 to 99) at the final follow-up assessment in 1024 hips, 16,18,2224,3032 while the mean incidence of thigh pain was 1.6% (0% to 11%) in 741 hips. 16,17,22,25,26,28,31 The mean intra-operative periprosthetic fracture rate was 3.3% (0% to 13.3%) in 1247 hips, whereas the mean coronal stem malalignment rate was 18.8% (5.2% to 60%) in 574 hips. The mean incidence of incorrect stem sizing was 10.4% (6.3% to 20%) in 596 hips. 16,22,23,28,31 The mean rate of > 2-mm stem subsidence was 5.3% (0% to 11%) in 444 hips 22,23,26,27,32 and the mean rate of stress shielding was 26.9% (5.2% to 66%) in 556 hips. 16,22,26,28,31

Metaphyseal total hip arthroplasty (METHA)

The METHA (Aesculap) is an uncemented neck-retaining monoblock or modular stem (Fig. 2). It is made of a titanium alloy with a proximal rough titanium, plasmasprayed, microporous surface coated with 20-μm dicalcium phosphate dihydrate (CaHPO4x2H2O). It has a proximal trapezoidal section providing a cortical multipoint contact. It loads medially on the calcar region and laterally on the proximal lateral cortex with its angulated distal end. This shape aims to enhance proximal load transfer in both medial and lateral sides.

Fig. 2
Fig. 2

METHA stem at eight years of follow-up.

Citation: EFORT Open Reviews 3, 5; 10.1302/2058-5241.3.170052

The METHA stem demonstrated a mean survivorship of 95.9% (92% to 98%) with stem revision as the endpoint, at a mean follow-up of 4.5 years (2.8 to 5.8) in 556 hips. 3336 Schnurr et al 37 investigated the METHA revision rate, distinguishing between monoblock and modular stems. In a population including 1090 monoblock stems, 314 modular stems with a titanium neck and 230 modular stems with a cobalt chrome neck, they reported a seven-year revision rate of 4.6% for both monoblock and modular cobalt chrome neck stems, and 7.5% for hips with modular titanium neck stems. The mean HHS at the final follow-up assessment was 92.2 points (89.9 to 97 points) in 632 hips with a mean follow-up of 4.1 years (2.7 to 5.8). In one study of 151 hips, 35 the authors evaluated the incidence of thigh pain, reporting no cases of severe or disabling thigh pain in the patient-administered questionnaire. The mean intra-operative peri-prosthetic fracture rate was 0.7% (0% to 2.4%) in 556 hips. 3336 In one study of 250 hips, 36 the authors evaluated the coronal stem malalignment reporting valgus position (> 140°) in 5.6% of the hips, and varus position (< 130°) in 19.8%. The mean rate of > 2-mm stem subsidence was 1.3% (0.4% to 3.9%) in 550 hips 3436,38 and the mean rate of stress shielding was 2.5% in 250 hips. 36

Shin et al 39 compared the METHA stem with a conventional-length femoral stem (BiCONTACT, Aesculap) including 50 hips in each group matched for age, sex, body mass index (BMI), height, surgical approach and surgeon. The authors did not find significant differences between the two groups in terms of post-operative radiographic outcomes, functional outcomes or complications. However, the short stem was associated with a higher incidence of malalignment (4% versus 2%) and subsidence (2% versus 0%) and a lower incidence of thigh pain (0% versus 4%) compared with a conventional-length femoral stem. No patient in either group underwent revision surgery for aseptic loosening with a mean follow-up of 58 months (36 to 83).

Mayo

The Mayo (ZimmerBiomet) is a short, double-tapered stem. Its design provides a four-point fixation in the metaphysis, loading the calcar region and the lateral cortex of the proximal femur. It is made of a Tivanium® alloy with fibre metal pads for biological ingrowth. It is also available with and without a Calcicoat Ceramic Coating (HA/TCP) in the proximal part.

The Mayo stem demonstrated a mean survivorship of 95.4% (92.3% to 100%) with aseptic loosening as the endpoint, at a mean follow-up of 4.7 years (2 to 7.9) in 592 hips. 7,8,4046 The mean HHS was 91 points (85 to 96) at the final follow-up assessment in 592 hips, 7,8,4046 while the mean incidence of thigh pain was 1.6% (0% to 2.7%) in 250 hips. 8,42,44 The mean intra-operative peri-prosthetic fracture rate was 6.8% (0% to 12.1%) in 529 hips. 7,8,40,42,4446 In two studies including 90 hips, 42,46 the authors evaluated the coronal stem malalignment reporting valgus position in 25.5% of the hips and varus position in 31.1%. The mean rate of > 2-mm stem subsidence was 3% (0% to 7%) in 302 hips 8,40,4244 and the mean rate of stress shielding was 5.6% (4.1% to 6.7%) in 238 hips. 7,8,42

Proxima

The Proxima (DePuy) is characterized by a tapered, trapezoidal geometry and lateral flare fitting with proximal femoral internal shape (Fig. 3). It is made of a titanium alloy with a rough titanium microporous surface coated with 30-μm thick hydroxyapatite except for the distal tip. It extends up to the junction between the metaphysis and diaphysis and provides a transfer load to the calcar and lateral cortex.

Fig. 3
Fig. 3

Proxima stem at five years of follow-up.

Citation: EFORT Open Reviews 3, 5; 10.1302/2058-5241.3.170052

In one study enrolling 129 hips, the prototype design demonstrated a survivorship of 100% with aseptic loosening as the endpoint, at a mean follow-up of eight years. 47 The mean HHS was 95 points with no patients complaining of thigh pain. The rate of incorrect sizing of the stem was 23%.

The Proxima stem demonstrated a mean survivorship of 100% at a mean follow-up of 4.2 years (1.7 to 6.5) in 749 hips, with aseptic loosening as the endpoint. 4855 The mean HHS was 92.2 points (86 to 98) at the final follow-up assessment in 749 hips, 4855 with no authors reporting cases of thigh pain. The mean intra-operative peri-prosthetic fracture rate was 1.8% (0% to 3%) and the mean coronal stem malalignment rate was 15.7% (5.4% to 32.3%) in 749 hips. 4855 The incidence of neck stress shielding was in the range of 50% to 100% in six of these studies. The mean rate of > 2-mm stem subsidence was 0.2% (0% to 0.8%). In one study including 65 hips, 53 the incidence of incorrect stem sizing was 53.8%.

Some authors compared this ultra-short stem with conventional uncemented stems, 50,56,57 including 354 hips in each group. At a mean follow-up of 5.9 years (1.5 to 11.8), the ultra-short stem showed no differences from conventional cementless stems in terms of validated functional outcomes scores or fixation, although lower risk of thigh pain and proximal stress shielding was reported. Some authors also compared the Proxima with a metaphyseal short stem 58 and an ultra-short non-anatomic stem. 59 In both studies, there were no significant differences between the two groups in terms of validated functional outcomes scores, incidence of thigh pain, revision rates, aseptic loosening rate and complication rates.

CUT

The CUT (ESKA Implants) is an uncemented neck-retaining modular stem (Fig. 4). It is made of a titanium alloy and its surface has a three-dimensional spongy metal structure (tripods). The shape of the prosthesis is straight and oval in the proximal part and curved in the distal part, becoming narrower at its tip in order to contact the calcar and the lateral femoral cortex.

Fig. 4
Fig. 4

CUT stem at three years of follow-up.

Citation: EFORT Open Reviews 3, 5; 10.1302/2058-5241.3.170052

The CUT stem demonstrated a mean survivorship of 96.4% (69.6% to 100%) at a mean follow-up of five years (3 to 8) in 690 hips, 6067 with aseptic loosening as the endpoint. The mean HHS was 92 points (85 to 98) at the final follow-up assessment in 690 hips, 6067 while the mean incidence of thigh pain was 2.9% (1% to 5.1%). The mean intra-operative peri-prosthetic fracture rate was 0.6% (0% to 2.4%) and the mean incidence of > 2-mm subsided stems was 3.4% (0.8% to 7.7%). Only the study performed by Steens et al 63 evaluated the coronal malalignment and the improper sizing of the stem resulting in 28% and 27.3% of the cases, respectively. On the other hand, only the study performed by Nieuwenhuijse et al 66 investigated the proximal stress shielding, reporting a rate of 12.8%.

Nanos

The Nanos stem (Smith&Nephew) is an uncemented neck-retaining stem (Fig. 5). It is made of a titanium alloy coated with calcium phosphate on approximately 75% of its surface. It is wedged in the sagittal and coronal plane with a curved distal end, providing a cortical multipoint contact and loading on both the calcar region and proximal lateral cortex.

Fig. 5
Fig. 5

Nanos stem at seven years of follow-up.

Citation: EFORT Open Reviews 3, 5; 10.1302/2058-5241.3.170052

The Nanos stem demonstrated a survivorship of 100% with stem revision for any reason as the endpoint, at a mean follow-up of 4.4 years (2.3 to 5.6) in 193 hips. 6870 The mean HHS at the final follow-up assessment was 93.6 points (90 to 97 points) in 193 hips. 6870 In two studies including 109 hips, 69,70 the authors investigated the incidence of thigh pain reporting two cases (1.8%) of slight non-disabling pain, and the coronal stem malalignment reporting valgus and varus position in 1.8% of the hips, respectively. The mean intra-operative peri-prosthetic fracture rate was 1.5% (0% to 3.6%) in 193 hips. 6870 Only one study including 37 hips 70 investigated the proximal stress shielding, reporting a rate of 27%.

Tri-Lock bone preservation system (BPS)

The Tri-Lock BPS (DePuy) is a short tapered-wedge stem. It is made of a titanium alloy with a highly porous and roughened coating (Gription®) in the proximal part.

The Tri-Lock stem demonstrated a mean survivorship of 99.5% (99.2% to 100%) with femoral revision as the endpoint, at a mean follow-up of 3.4 years (2.3 to 5) in 475 hips. 7173 The mean HHS was 86.5 points (85 to 88) at the final follow-up assessment, while the mean incidence of thigh pain was 12.3% (1.6% to 16%). In two studies including 415 hips, 72,73 the mean intra-operative peri-prosthetic fracture rate was 0.5% (0% to 1.6%) and the coronal stem alignment was valgus and varus in 20.5% and 7.5% of the hips, respectively. Amendola et al 73 also investigated the onset of cortical hypertrophy and femoral stress shielding, reporting an incidence of 2% and 64.5%, respectively. On the other hand, Albers et al 72 investigated the onset of stem subsidence, reporting an incidence of 39.8% with an average of 1.04 mm (0.5 to 5).

Global tissue sparing (GTS)

The GTS (ZimmerBiomet) is an uncemented monoblock stem (Fig. 6). It is made of a titanium-based alloy with a rough surface to promote bone ingrowth. The metaphyseal anchorage and rotational stability are provided by the tapered elliptic-octagonal cross-section of the stem, longitudinal anterior and posterior fins, and femoral bone compaction.

Fig. 6
Fig. 6

GTS stem at seven years of follow-up.

Citation: EFORT Open Reviews 3, 5; 10.1302/2058-5241.3.170052

The GTS stem demonstrated a survivorship of 100% with femoral revision for any cause as the endpoint, at a mean follow-up of 1.9 years (1.4 to 2.3) in 229 hips. 74,75 The mean Merle d’Aubigné clinical score was 17.5 points at the final follow-up assessment. The intra-operative peri-prosthetic fracture rate was 0.9% in 229 hips. The coronal stem malalignment consisted in the varus position in 4.3% of the hips. In both studies, no cases of stem subsidence and proximal stress shielding were reported.

Fitmore

The Fitmore (ZimmerBiomet) is an uncemented monoblock stem (Fig. 7). It is made of a titanium alloy with a proximal rough titanium, plasma-sprayed, porous coating to promote the bone ingrowth. It was designed to achieve a more physiological proximal load transfer with the main amount of loading force focused on the calcar region.

Fig. 7
Fig. 7

Fitmore stem at seven years of follow-up.

Citation: EFORT Open Reviews 3, 5; 10.1302/2058-5241.3.170052

The Fitmore stem demonstrated a survivorship of 100% with femoral revision for loosening as the endpoint, at a mean follow-up of 1.3 years in 500 hips. 76 The intra-operative peri-prosthetic fracture rate was 0.2%. In the first 100 cases, the authors reported > 2-mm stem subsidence in 34% of the hips and diaphyseal cortical hypertrophy in 29% of the hips.

Radiostereometric analysis

RSA is the gold-standard measure for the assessment of early migration because of its accuracy and predictive value. 77 It requires prospective planning, implantation of tantalum markers and special stereoradiographs. 78 In patients undergoing conventional THA, early implant migration represents the best predictor of mechanical failure and, therefore, it is an important factor impairing the long-term survival of the prosthesis. 79

Acklin et al 80 conducted a prospective cohort study of 34 patients undergoing THA with Fitmore to measure the stem migration at 3, 6, 12 and 24 months post-operatively. At three months, the mean subsidence was -0.39 mm (95% confidence interval (CI) -0.60 to -0.18) and it was stable at two years, while the mean internal rotation along the longitudinal axis was 1.09° (95% CI 0.52 to 1.66) at two years. Budde et al 81 evaluated the migration of Nanos short-stem implants in 14 patients at 3, 6, 12 and 24 months post-operatively. The highest value of mean subsidence along the proximo-distal axis was –0.22 ± 0.39 mm at three months, while the highest value of mean rotational migration along the longitudinal axis was 0.8° ± 3.2 at 12 months. The mean total migration was 0.46 ± 0.31 mm at 12 months, but the greatest proportion occurred within three months after surgery (0.40 ± 0.34 mm). According to these studies, 80,81 Fitmore and Nanos short stems seem to be affected by an early slight migration and rotation within three months after surgery, followed by a secondary stable fixation.

McCalden et al 82 performed a randomized controlled trial (RCT) comparing the patterns of migration of a short modular stem with metaphyseal fixation (SMF; Smith&Nephew) in 22 patients with those of a standard-length stem with metaphyseal fixation (Synergy, Smith&Nephew) in 21 patients. At 24 months after surgery, there was no statistically significant difference in mean migration between the groups: total migration was 1.09 ± 1.74 mm and 0.73 ± 0.72 mm, respectively. The vast majority of stems in both groups had a total migration < 0.6 mm, subsidence < 0.5 mm and rotation < 1.0°. In the group with SMF, three of them had an early migration > 1.0 mm which then stabilized within six months, and one of them had an early progressive migration requiring revision three years after surgery.

Röhrl et al 27 investigated the migration of CFP in 26 hips followed for two years post-operatively. The stem demonstrated a good early fixation, as shown by the low mean subsidence (0.05 ± 0.06 mm) and the low mean varus-valgus tilting (0.03 ± 0.01). However, the stem reported an early retroversion movement (0.6 ± 0.3), which stabilized within the first year after surgery.

Nieuwenhuijse et al 66 evaluated the migration of CUT in 39 hips followed up to five years after surgery, taking into account mediolateral, craniocaudal and anteroposterior (AP) migration. The median total tip migration was 0.42 mm (0.09 to 9.36) at six weeks and 0.89 mm (0.13 to 6.39) at five years. Although 74% of stems had a migration > 1 mm in the mediolateral or craniocaudal or AP direction, only 10% were considered loose. One of them showed a rapid initial migration without any tendency to stabilize; the remaining three showed continuous excessive migration continuing after two years of follow-up.

Mahmoud et al 83 investigated the migration of Proxima in 28 hips followed for two years after surgery. The mean subsidence and varus tilt were low, such as 0.22 ± 0.28 mm and 1.04 ± 0.81. In all stems, the migration and rotation occurred within three months after surgery and resulted in a secondary stable fixation. No cases of loosening were reported.

Einzel-Bild-Roentgen-Analyse femoral component analysis (EBRA-FCA)

EBRA-FCA is a non-invasive method characterized by the retrospective analysis of routinely taken AP view radiographs. Its sensitivity and specificity for detecting an implant migration of 1 mm are 78% and 100%, respectively. 84 Moreover, some authors demonstrated that an axial subsidence > 1.5 mm measured with the EBRA method at two years from THA with conventional cementless straight-stem is predictive for late aseptic loosening and, therefore, a potential cause of revision of the prosthesis. 85

Schmidutz et al 86 performed an EBRA-FCA assessment of 80 of the first 100 consecutive hips receiving a METHA available as a monoblock or as a modular implant with cone adapters. After an average follow-up of 2.7 years (2.0 to 4.2), the average subsidence of the stems was 0.7 ± 1.8 mm with no implants requiring revision surgery. The vast majority of the implants (92.5%) were primarily stable with a mean migration of -0.2 ± 0.35 mm. The 5% of the stems showed a secondary stabilization within two months after an initial subsidence. Finally, 2.5% of the stems showed a continuous subsidence. For this reason, the authors concluded that the METHA short stem provides a high degree of stability after two years.

Kutzner et al 87 investigated the migration of metaphyseal-anchoring, calcar-guided short stem (Optimys, Mathys Ltd.) in 202 hips for a two-year follow-up period. The average axial subsidence of the stems was 1.43 ± 1.45 mm with no implants requiring revision surgery. In all stems, the subsidence was pronounced in the first post-operative months followed by secondary stabilization. The authors also demonstrated that age, BMI and different offset versions did not affect the amount of implant migration. In another study including 216 hips undergoing THA with the Optimys stem, Kutzner et al 88 investigated the relationship between varus and valgus positioning and stem stability. The authors divided the hips into five groups according to the mean value of the caput-collum-diaphyseal (CCD) angle (123.3°, 128.0°, 132.4°, 137.5° and 142.5°, respectively). After two years, the axial subsidence and the mean varus/valgus tilt were significantly increased in stems with valgus alignment. However, none of the stems required revision for loosening.

Dual-energy x-ray absorptiometry (DEXA) analysis

Some authors investigated the bone remodelling characteristics of the femur after THA with a METHA stem by using DEXA assessment and adapting Gruen zones (R1 to R7) to the short stem design. 8992 In all studies including 176 hips with at least one year of follow-up, the bone mineral density (BMD) significantly increased in the lateral regions (R2 and R3) and significantly decreased in the proximal regions (R1 and R7). On the other hand, changes in distal (R4), distal-medial (zone 5) and lesser trochanter (R6) regions were less relevant and reliable across the analysed studies. These results suggest a good osseointegration of the stem, but the load transfer seems to occur particularly in the lateral and distal-medial regions, favouring proximal stress shielding and bone atrophy in the great trochanter and calcar regions.

Zeh et al 93 investigated the bone remodelling with the Nanos stem in 25 hips up to 12 months post-operatively. The DEXA scan demonstrated a significant increase in BMD in R6 according to Gruen (12%) and a significant decrease in R1 (-15%), R2 (-5%) and R7 (-12%), suggesting a load transfer in the medial-distal part of the femoral metaphysis. In a previous study including 36 hips, Götze et al 94 reported a decrease of BMD in R1 (-6.4%) and R7 (-7.2%) but demonstrated an increase of BMD in R2 (9.7 %) due to bone ingrowth in the lateral-distal region at one year follow-up. The authors concluded that a proper proximal load transfer could not be achieved with this stem, resulting in proximal stress shielding.

Logroscino et al 95 compared the bone remodelling around the Nanos stem (12 hips) with that around the Proxima stem (19 hips), reporting an increase of peri-prosthetic BMD with both implants. In the Nanos group, BMD values were significantly higher in the R3 and R4 zones, whereas there were no differences in the R1, R2 and R5 zones. No cases of stress shielding were reported in either group. On the other hand, Brinkmann et al 96 performed a DEXA prospective RCT comparing the Nanos stem (26 hips) with METHA stem (24 hips). At 12 months, the DEXA scans showed a decrease of BMD in the R1 zone for both METHA and Nanos stems (-8% and -14%, respectively) and an increase of BMD in R6 zone (9%) for the METHA stem.

Gasbarra et al 97 evaluated bone remodelling around the Fitmore stem in 33 hips. At one year follow-up, a greater BMD increase was reported in R7 (8.3%). Positive changes of BMD values were also reported in the R1, R3 and R5 zones (1.7%, 4.1% and 2.1%, respectively), whereas negative changes were reported in the R2 and R4 zones (-4.8% and -1.8%, respectively). These findings suggest a significant load transfer in the medial proximal region of the femur, preventing its bone resorption as reported with other short stems. Moreover, Freitag et al 98 compared the bone remodelling around the Fitmore stem (57 hips) with that around a cementless straight stem (CLS, ZimmerBiomet) (81 hips) at one year follow-up. The authors demonstrated a more significant proximal load transfer with the short stem, as shown by the most pronounced peri-prosthetic BMD changes in the proximal medial region R7 (-17.2% versus -16.7%). Finally, the BMD reduction in R6 zone was less relevant with the short stem (-4.7% versus -10.8%).

Chen et al 99 performed a DEXA study including 29 hips undergoing THA with the Mayo stem, with an average follow-up of 5.7 years (1 to 12). Compared with the contralateral side, the greater decrease in the BMD values was reported in the proximal zones (-14.4% in R1, -14.4% in R6 and -17.9% in R7). On the other hand, a significant increase in BMD values was demonstrated in the lateral side zones (R2 9.2% in R2 and 20.9% in R3).

Lazarinis et al 100 performed a prospective cohort study enrolling 30 hips receiving the CFP stem. The DEXA analysis was performed in 27 hips and showed a significant decrease of BMD values in R7 (-31%), R6 (-19%) and R2 (-13%) zones at one year follow-up. Two years after surgery, the bone loss in these regions did not recover, whereas the less relevant bone loss in the R1, R3 and R5 zones partially recovered. According to these results, the CFP stem seems to transfer loads distally leading to proximal peri-prosthetic bone loss.

Finally, Salemyr et al 101 performed a RCT comparing Proxima (26 hips) with a conventional tapered titanium stem (Bi-metric, Biomet) (25 hips) in terms of changes in peri-prosthetic BMD in Gruen zones 1 and 7, two years after surgery. The authors concluded that the ultra-short stem provided lower peri-prosthetic bone loss with a mean difference of 18% (95% CI -27 to -10) in R1 and 5% (95% CI -12 to -3) in R7.

Conclusions

Conservative stems included in this review showed a survivorship in the range of 96% to 100% in the short term, despite the fact that they can be associated with complications such as stem malalignment, incorrect stem sizing and intra-operative fracture. The vast majority of stems demonstrated a good osseointegration, but some prostheses transferred loads particularly to the lateral and distal-medial regions favouring proximal stress shielding and bone atrophy in the great trochanter and calcar regions. Finally, some conservative stems were affected by an early slight migration and rotation within the first months after surgery, followed by a secondary stable fixation.

Although the clinical and radiological outcomes of some conservative stems are promising, their use in clinical practice needs careful indications and proper surgical technique. Because no studies with long-term follow-up are currently available in the literature, comparative studies with a longer follow-up are strongly recommended to demonstrate that conservative stems can provide long-term results comparable to well-established conventional uncemented stems.

Open access

This article is distributed under the terms of the Creative Commons Attribution-Non Commercial 4.0 International (CC BY-NC 4.0) licence (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed.

ICMJE Conflict of interest statement

G. Grappiolo declares consultancy, royalties and payment for lectures from Zimmer Biomet, activities outside the submitted work.

Funding statement

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

References

  • 1.

    Dunbar MJ . Cemented femoral fixation: the North Atlantic divide. Orthopedics 2009;32:32.

  • 2.

    Australian Orthopaedic Association National Joint Replacement Registry. Annual Report. Adelaide: AOA; 2014.

  • 3.

    Morshed S , Bozic KJ , Ries MD , Malchau H , Colford JM Jr . Comparison of cemented and uncemented fixation in total hip replacement: a meta-analysis. Acta Orthop 2007;78:315-326.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4.

    Troelsen A , Malchau E , Sillesen N , Malchau H . A review of current fixation use and registry outcomes in total hip arthroplasty: the uncemented paradox. Clin Orthop Relat Res 2013;471:2052-2059.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Spotorno L , Romagnoli S , Ivaldo N et al.. The CLS system. Theoretical concept and results. Acta Orthop Belg 1993;59(suppl 1):144-148.

  • 6.

    Grappiolo G , Blaha JD , Gruen TA , Burastero G , Spotorno L . Primary total hip arthroplasty using a grit-blasted, press-fit femoral prosthesis.Long-term results with survivorship analysis. Hip Int 2002;12:55-72.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 7.

    Goebel D , Schultz W . The Mayo cementless femoral component in active patients with osteoarthritis. Hip Int 2009;19:206-210.

  • 8.

    Morrey BF , Adams RA , Kessler M . A conservative femoral replacement for total hip arthroplasty. A prospective study. J Bone Joint Surg [Br] 2000;82-B:952-958.

  • 9.

    Rometsch E , Bos PK , Koes BW . Survival of short hip stems with a “modern”, trochanter-sparing design - a systematic literature review. Hip Int 2012;22:344-354.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10.

    Banerjee S , Pivec R , Issa K et al.. Outcomes of short stems in total hip arthroplasty. Orthopedics 2013;36:700-707.

  • 11.

    McTighe TSS , Keppler L , Keggi J et al.. A classification system for short stem uncemented total hip arthroplasty. Bone Joint J 2013;95:260.

  • 12.

    Khanuja HS , Banerjee S , Jain D , Pivec R , Mont MA . Short bone-conserving stems in cementless hip arthroplasty. J Bone Joint Surg [Am] 2014;96:1742-1752.

  • 13.

    Falez F , Casella F , Papalia M . Current concepts, classification, and results in short stem hip arthroplasty. Orthopedics 2015;38 (suppl):S6-S13.

  • 14.

    Feyen H , Shimmin AJ . Is the length of the femoral component important in primary total hip replacement? Bone Joint J 2014;96-B:442-448.

  • 15.

    van Oldenrijk J , Molleman J , Klaver M , Poolman RW , Haverkamp D . Revision rate after short-stem total hip arthroplasty: a systematic review of 49 studies. Acta Orthop 2014;85:250-258.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Nowak M , Nowak TE , Schmidt R et al.. Prospective study of a cementless total hip arthroplasty with a collum femoris preserving stem and a trabeculae oriented pressfit cup: minimun 6-year follow-up. Arch Orthop Trauma Surg 2011;131:549-555.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17.

    Pipino FML , Molfetta L , Grandizio M . Preservation of the femoral neck in hip arthroplasty: results of a 13-17 year follow-up. J Orthop Traumatol 2000;1:31-39.

  • 18.

    Kendoff DO , Citak M , Egidy CC , O’Loughlin PF , Gehrke T . Eleven-year results of the anatomic coated CFP stem in primary total hip arthroplasty. J Arthroplasty 2013;28:1047-1051.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19.

    Kress AM , Schmidt R , Nowak TE et al.. Stress-related femoral cortical and cancellous bone density loss after collum femoris preserving uncemented total hip arthroplasty: a prospective 7-year follow-up with quantitative computed tomography. Arch Orthop Trauma Surg 2012;132:1111-1119.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20.

    Ghera S , Bisicchia S . The collum femoris preserving stem: early results. Hip Int 2013;23:27-32.

  • 21.

    Li M , Hu Y , Li K et al.. [Mid-term effectiveness of total hip arthroplasty with collum femoris preserving prosthesis]. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2012;26:897-901.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 22.

    Molfetta L , Capozzi M , Caldo D . Medium term follow up of the Biodynamic neck sparing prosthesis. Hip Int 2011;21:76-80.

  • 23.

    Briem D , Schneider M , Bogner N et al.. Mid-term results of 155 patients treated with a collum femoris preserving (CFP) short stem prosthesis. Int Orthop 2011;35:655-660.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24.

    Ding S , Zheng K . [Artificial total hip arthroplasty with collum femoris preserving for treating hip joint]. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2010;24:1-4.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 25.

    Shang XF , He R , Lu YF et al.. [Total hip replacement with collum femoris preserving for the treatment of advanced stage of femoral head necrosis of young patients: a report of results of more than five years follow-up]. Zhonghua Wai Ke Za Zhi 2010;48:1298-1300.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 26.

    Gill IR , Gill K , Jayasekera N , Miller J . Medium term results of the collum femoris preserving hydroxyapatite coated total hip replacement. Hip Int 2008;18:75-80.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 27.

    Röhrl SM , Li MG , Pedersen E , Ullmark G , Nivbrant B . Migration pattern of a short femoral neck preserving stem. Clin Orthop Relat Res 2006;448:73-78.

  • 28.

    Pons M . Learning curve and short-term results with a short-stem CFP system. Hip Int 2010;20(suppl 7):S52-S57.

  • 29.

    Pipino F . CFP prosthetic stem in mini-invasive total hip arthroplasty. J Orthop Traumatol 2004;5:165-171.

  • 30.

    You RJ , Zheng WZ , Chen K et al.. Long-term effectiveness of total hip replacement with the collum femoris preserving prosthesis. Cell Biochem Biophys 2015;72:43-47.

  • 31.

    Li M , Hu Y , Xie J . Analysis of the complications of the collum femoris preserving (CFP) prostheses. Acta Orthop Traumatol Turc 2014;48:623-627.

  • 32.

    Hutt J , Harb Z , Gill I et al.. Ten year results of the collum femoris preserving total hip replacement: a prospective cohort study of seventy five patients. Int Orthop 2014;38:917-922.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 33.

    Chammaï Y , Brax M . Medium-term comparison of results in obese patients and non-obese hip prostheses with Metha® short stem. Eur J Orthop Surg Traumatol 2015;25:503-508.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 34.

    Floerkemeier T , Tscheuschner N , Calliess T et al.. Cementless short stem hip arthroplasty METHA® as an encouraging option in adults with osteonecrosis of the femoral head. Arch Orthop Trauma Surg 2012;132:1125-1131.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 35.

    Thorey F , Hoefer C , Abdi-Tabari N et al.. Clinical results of the metha short hip stem: a perspective for younger patients? Orthop Rev (Pavia) 2013;5:e34.

  • 36.

    Wittenberg RH , Steffen R , Windhagen H , Bücking P , Wilcke A . Five-year results of a cementless short-hip-stem prosthesis. Orthop Rev (Pavia) 2013;5:e4.

  • 37.

    Schnurr C , Schellen B , Dargel J et al.. Low short-stem revision rates: 1-11 year results from 1888 total hip arthroplasties. J Arthroplasty 2017;32:487-493.

  • 38.

    Schmidutz F , Grote S , Pietschmann M et al.. Sports activity after short-stem hip arthroplasty. Am J Sports Med 2012;40:425-432.

  • 39.

    Shin YS , Suh DH , Park JH , Kim JL , Han SB . Comparison of specific femoral short stems and conventional-length stems in primary cementless total hip arthroplasty. Orthopedics 2016;39:e311-e317.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 40.

    Falez F , Casella F , Panegrossi G , Favetti F , Barresi C . Perspectives on metaphyseal conservative stems. J Orthop Traumatol 2008;9:49-54.

  • 41.

    Gagała J , Mazurkiewicz T . [Early experiences in the use of Mayo stem in hip arthroplasty]. Chir Narzadow Ruchu Ortop Pol 2009;74:152-156.

  • 42.

    Gilbert RE , Salehi-Bird S , Gallacher PD , Shaylor P . The Mayo Conservative Hip: experience from a district general hospital. Hip Int 2009;19:211-214.

  • 43.

    Zeh A , Weise A , Vasarhelyi A , Bach AG , Wohlrab D . [Medium-term results of the Mayo™ short-stem hip prosthesis after avascular necrosis of the femoral head]. Z Orthop Unfall 2011;149:200-205.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 44.

    Cruz-Vázquez FJ , De la , Rosa-Aguilar M , Gómez-López CA . [Evaluation of the uncemented Mayo femoral stem. The first 10 years]. Acta Ortop Mex 2011;25:108-113.

  • 45.

    Martins LG , Garcia FL , Picado CH . Aseptic loosening rate of the Mayo femoral stem with medium-term follow up. J Arthroplasty 2014;29:2122-2126.

  • 46.

    Arnholdt J , Gilbert F , Blank M et al.. The Mayo conservative hip: complication analysis and management of the first 41 cases performed at a University level 1 department. BMC Musculoskelet Disord 2017;18:250.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 47.

    Santori FS , Santori N . Mid-term results of a custom-made short proximal loading femoral component. J Bone Joint Surg [Br] 2010;92:1231-1237.

  • 48.

    Kim YH , Kim JS , Park JW , Joo JH . Total hip replacement with a short metaphyseal-fitting anatomical cementless femoral component in patients aged 70 years or older. J Bone Joint Surg [Br] 2011;93:587-592.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 49.

    Kim YH , Park JW , Kim JS . Is diaphyseal stem fixation necessary for primary total hip arthroplasty in patients with osteoporotic bone (Class C bone)? J Arthroplasty 2013;28:139-46.e1.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 50.

    Kim YH , Oh JH . A comparison of a conventional versus a short, anatomical metaphyseal-fitting cementless femoral stem in the treatment of patients with a fracture of the femoral neck. J Bone Joint Surg [Br] 2012;94:774-781.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 51.

    Kim YH , Kim JS , Joo JH , Park JW . A prospective short-term outcome study of a short metaphyseal fitting total hip arthroplasty. J Arthroplasty 2012;27:88-94.

  • 52.

    Tóth K , Mécs L , Kellermann P . Early experience with the Depuy Proxima short stem in total hip arthroplasty. Acta Orthop Belg 2010;76:613-618.

  • 53.

    Ghera S , Pavan L . The DePuy Proxima hip: a short stem for total hip arthroplasty. Early experience and technical considerations. Hip Int 2009;19:215-220.

  • 54.

    Malhotra R , Kumar V . Mid-term outcome of total hip arthroplasty using a short stem. J Orthop Surg (Hong Kong) 2016;24:323-327.

  • 55.

    Choi YW , Kim SG . The short-term clinical outcome of total hip arthroplasty using short metaphyseal loading femoral stem. Hip Pelvis 2016;28:82-89.

  • 56.

    Kim YH , Park JW , Kim JS . Ultrashort versus conventional anatomic cementless femoral stems in the same patients younger than 55 years. Clin Orthop Relat Res 2016;474:2008-2017.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 57.

    Henry BM , Wrażeń W , Hynnekleiv L et al.. Health-related quality-of-life and functional outcomes in short-stem versus standard-stem total hip arthroplasty: an 18-month follow-up cohort study. Med Sci Monit 2016;22:4406-4414.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 58.

    Kim YH , Park JW , Kim JS . Metaphyseal engaging short and ultra-short anatomic cementless stems in young and active patients. J Arthroplasty 2016;31:180-185.

  • 59.

    Kim YH , Park JW , Kim JS . Short-term results of ultra-short anatomic vs ultra-short non-anatomic proximal loading uncemented femoral stems. J Arthroplasty 2018;33:149-155.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 60.

    Ender SA , Machner A , Hubbe J , Pap G , Neumann HW . [Medium-term results of the cementless femoral neck prosthesis CUT]. Z Orthop Ihre Grenzgeb 2006;144:477-483.

  • 61.

    Ender SA , Machner A , Pap G , Grasshoff H , Neumann HW . [The femoral neck prosthesis CUT. Three- to six-year results]. Orthopade 2006;35:841-847.

  • 62.

    Ender SA , Machner A , Pap G et al.. Cementless CUT femoral neck prosthesis: increased rate of aseptic loosening after 5 years. Acta Orthop 2007;78:616-621.

  • 63.

    Steens W , Skripitz R , Schneeberger AG et al.. [Cementless femoral neck prosthesis CUT–clinical and radiological results after 5 years]. Z Orthop Unfall 2010;148:413-419.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 64.

    Rudert M , Leichtle U , Leichtle C , Thomas W . [Implantation technique for the CUT-type femoral neck endoprosthesis]. Oper Orthop Traumatol 2007;19:458-472.

  • 65.

    Thomas W , Lucente L , Mantegna N , Grundei H . [ESKA (CUT) endoprosthesis]. Orthopade 2004;33:1243-1248.

  • 66.

    Nieuwenhuijse MJ , Valstar ER , Nelissen RG . 5-year clinical and radiostereometric analysis (RSA) follow-up of 39 CUT femoral neck total hip prostheses in young osteoarthritis patients. Acta Orthop 2012;83:334-341.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 67.

    Ishaque BA , Gils J , Wienbeck S et al.. [Results after replacement of femoral neck prostheses - thrust plate prosthesis (TPP) versus ESKA cut prosthesis]. Z Orthop Unfall 2009;147:79-88.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 68.

    Stadler N , Lehner J , Abbas R , Trieb K . Prospective mid-term results of a consecutive series of a short stem. Acta Orthop Belg 2016;82:372-375.

  • 69.

    Ettinger M , Ettinger P , Lerch M et al.. The NANOS short stem in total hip arthroplasty: a mid term follow-up. Hip Int 2011;21:583-586.

  • 70.

    Capone A , Bienati F , Torchia S , Podda D , Marongiu G . Short stem total hip arthroplasty for osteonecrosis of the femoral head in patients 60 years or younger: a 3- to 10-year follow-up study. BMC Musculoskelet Disord 2017;18:301.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 71.

    Sperati G , Ceri L . Total hip arthroplasty using TRI-LOCK® DePuy bone preservation femoral stem: our experience. Acta Biomed 2014;85(suppl 2):66-70.

  • 72.

    Albers A , Aoude AA , Zukor DJ et al.. Favorable results of a short, tapered, highly porous, proximally coated cementless femoral stem at a minimum 4-year follow-up. J Arthroplasty 2016;31:824-829.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 73.

    Amendola RL , Goetz DD , Liu SS , Callaghan JJ . Two- to 4-year followup of a short stem THA construct: excellent fixation, thigh pain a concern. Clin Orthop Relat Res 2017;475:375-383.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 74.

    Morales de Cano JJ , Gordo C , Illobre JM . Early clinical results of a new conservative hip stem. Eur J Orthop Surg Traumatol 2014;24:359-363.

  • 75.

    Morales de Cano JJ , Gordo C , Canosa Areste J . Short femoral stem in total hip arthroplasty: stable fixation and low complication rates in elderly patients. Hip Int 2017;27:311-316.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 76.

    Gustke K . Short stems for total hip arthroplasty: initial experience with the Fitmore stem. J Bone Joint Surg [Br] 2012;94 (suppl A):47-51.

  • 77.

    Hurschler C , Seehaus F , Emmerich J , Kaptein BL , Windhagen H . Accuracy of model-based RSA contour reduction in a typical clinical application. Clin Orthop Relat Res 2008;466:1978-1986.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 78.

    Kärrholm J , Herberts P , Hultmark P et al.. Radiostereometry of hip prostheses. Review of methodology and clinical results. Clin Orthop Relat Res 1997;(344):94-110.

  • 79.

    Kärrholm J . Radiostereometric analysis of early implant migration - a valuable tool to ensure proper introduction of new implants. Acta Orthop 2012;83:551-552.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 80.

    Acklin YP , Jenni R , Bereiter H , Thalmann C , Stoffel K . Prospective clinical and radiostereometric analysis of the Fitmore short-stem total hip arthroplasty. Arch Orthop Trauma Surg 2016;136:277-284.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 81.

    Budde S , Seehaus F , Schwarze M et al.. Analysis of migration of the Nanos® short-stem hip implant within two years after surgery. Int Orthop 2016;40:1607-1614.

  • 82.

    McCalden RW , Korczak A , Somerville L , Yuan X , Naudie DD . A randomised trial comparing a short and a standard-length metaphyseal engaging cementless femoral stem using radiostereometric analysis. Bone Joint J 2015;97-B:595-602.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 83.

    Mahmoud AN , Kesteris U , Flivik G . Stable migration pattern of an ultra-short anatomical uncemented hip stem: a prospective study with 2 years radiostereometric analysis follow-up. Hip Int 2017;27:259-266.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 84.

    Biedermann R , Krismer M , Stöckl B et al.. Accuracy of EBRA-FCA in the measurement of migration of femoral components of total hip replacement. Einzel-Bild-Röntgen-Analyse-femoral component analysis. J Bone Joint Surg [Br] 1999;81:266-272.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 85.

    Krismer M , Biedermann R , Stöckl B et al.. The prediction of failure of the stem in THR by measurement of early migration using EBRA-FCA. Einzel-Bild-Roentgen-Analyse-femoral component analysis. J Bone Joint Surg [Br] 1999;81:273-280.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 86.

    Schmidutz F , Graf T , Mazoochian F et al.. Migration analysis of a metaphyseal anchored short-stem hip prosthesis. Acta Orthop 2012;83:360-365.

  • 87.

    Kutzner KP , Kovacevic MP , Freitag T et al.. Influence of patient-related characteristics on early migration in calcar-guided short-stem total hip arthroplasty: a 2-year migration analysis using EBRA-FCA. J Orthop Surg Res 2016;11:29.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 88.

    Kutzner KP , Freitag T , Donner S , Kovacevic MP , Bieger R . Outcome of extensive varus and valgus stem alignment in short-stem THA: clinical and radiological analysis using EBRA-FCA. Arch Orthop Trauma Surg 2017;137:431-439.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 89.

    Fischer M , Beckmann NA , Simank HG . Bone remodelling around the Metha®short stem implant - Clinical and dual-energy x-ray absorptiometry (DXA) results. J Orthop 2017;14:525-529.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 90.

    Jahnke A , Engl S , Altmeyer C et al.. Changes of periprosthetic bone density after a cementless short hip stem: a clinical and radiological analysis. Int Orthop 2014;38:2045-2050.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 91.

    Lerch M , von der Haar-Tran A , Windhagen H et al.. Bone remodelling around the Metha short stem in total hip arthroplasty: a prospective dual-energy X-ray absorptiometry study. Int Orthop 2012;36:533-538.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 92.

    Synder M , Krajewski K , Sibinski M , Drobniewski M . Periprosthetic bone remodeling around short stem. Orthopedics 2015;38(suppl):S40-S45.

  • 93.

    Zeh A , Pankow F , Röllinhoff M , Delank S , Wohlrab D . A prospective dual-energy X-ray absorptiometry study of bone remodeling after implantation of the Nanos short-stemmed prosthesis. Acta Orthop Belg 2013;79:174-180.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 94.

    Götze C , Ehrenbrink J , Ehrenbrink H . [Is there a bone-preserving bone remodelling in short-stem prosthesis? DEXA analysis with the Nanos total hip arthroplasty]. Z Orthop Unfall 2010;148:398-405.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 95.

    Logroscino G , Ciriello V , D’Antonio E et al.. Bone integration of new stemless hip implants (proxima vs. nanos). A DXA study: preliminary results. Int J Immunopathol Pharmacol 2011;24(suppl 2):113-116.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 96.

    Brinkmann V , Radetzki F , Delank KS , Wohlrab D , Zeh A . A prospective randomized radiographic and dual-energy X-ray absorptiometric study of migration and bone remodeling after implantation of two modern short-stemmed femoral prostheses. J Orthop Traumatol 2015;16:237-243.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 97.

    Gasbarra E , Celi M , Perrone FL et al.. Osseointegration of Fitmore stem in total hip arthroplasty. J Clin Densitom 2014;17:307-313.

  • 98.

    Freitag T , Hein MA , Wernerus D , Reichel H , Bieger R . Bone remodelling after femoral short stem implantation in total hip arthroplasty: 1-year results from a randomized DEXA study. Arch Orthop Trauma Surg 2016;136:125-130.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 99.

    Chen HH , Morrey BF , An KN , Luo ZP . Bone remodeling characteristics of a short-stemmed total hip replacement. J Arthroplasty 2009;24:945-950.

  • 100.

    Lazarinis S , Mattsson P , Milbrink J , Mallmin H , Hailer NP . A prospective cohort study on the short collum femoris-preserving (CFP) stem using RSA and DXA. Primary stability but no prevention of proximal bone loss in 27 patients followed for 2 years. Acta Orthop 2013;84:32-39.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 101.

    Salemyr M , Muren O , Ahl T et al.. Lower periprosthetic bone loss and good fixation of an ultra-short stem compared to a conventional stem in uncemented total hip arthroplasty. Acta Orthop 2015;86:659-666.

    • PubMed
    • Search Google Scholar
    • Export Citation

 

  • Collapse
  • Expand
  • 1.

    Dunbar MJ . Cemented femoral fixation: the North Atlantic divide. Orthopedics 2009;32:32.

  • 2.

    Australian Orthopaedic Association National Joint Replacement Registry. Annual Report. Adelaide: AOA; 2014.

  • 3.

    Morshed S , Bozic KJ , Ries MD , Malchau H , Colford JM Jr . Comparison of cemented and uncemented fixation in total hip replacement: a meta-analysis. Acta Orthop 2007;78:315-326.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4.

    Troelsen A , Malchau E , Sillesen N , Malchau H . A review of current fixation use and registry outcomes in total hip arthroplasty: the uncemented paradox. Clin Orthop Relat Res 2013;471:2052-2059.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5.

    Spotorno L , Romagnoli S , Ivaldo N et al.. The CLS system. Theoretical concept and results. Acta Orthop Belg 1993;59(suppl 1):144-148.

  • 6.

    Grappiolo G , Blaha JD , Gruen TA , Burastero G , Spotorno L . Primary total hip arthroplasty using a grit-blasted, press-fit femoral prosthesis.Long-term results with survivorship analysis. Hip Int 2002;12:55-72.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 7.

    Goebel D , Schultz W . The Mayo cementless femoral component in active patients with osteoarthritis. Hip Int 2009;19:206-210.

  • 8.

    Morrey BF , Adams RA , Kessler M . A conservative femoral replacement for total hip arthroplasty. A prospective study. J Bone Joint Surg [Br] 2000;82-B:952-958.

  • 9.

    Rometsch E , Bos PK , Koes BW . Survival of short hip stems with a “modern”, trochanter-sparing design - a systematic literature review. Hip Int 2012;22:344-354.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10.

    Banerjee S , Pivec R , Issa K et al.. Outcomes of short stems in total hip arthroplasty. Orthopedics 2013;36:700-707.

  • 11.

    McTighe TSS , Keppler L , Keggi J et al.. A classification system for short stem uncemented total hip arthroplasty. Bone Joint J 2013;95:260.

  • 12.

    Khanuja HS , Banerjee S , Jain D , Pivec R , Mont MA . Short bone-conserving stems in cementless hip arthroplasty. J Bone Joint Surg [Am] 2014;96:1742-1752.

  • 13.

    Falez F , Casella F , Papalia M . Current concepts, classification, and results in short stem hip arthroplasty. Orthopedics 2015;38 (suppl):S6-S13.

  • 14.

    Feyen H , Shimmin AJ . Is the length of the femoral component important in primary total hip replacement? Bone Joint J 2014;96-B:442-448.

  • 15.

    van Oldenrijk J , Molleman J , Klaver M , Poolman RW , Haverkamp D . Revision rate after short-stem total hip arthroplasty: a systematic review of 49 studies. Acta Orthop 2014;85:250-258.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16.

    Nowak M , Nowak TE , Schmidt R et al.. Prospective study of a cementless total hip arthroplasty with a collum femoris preserving stem and a trabeculae oriented pressfit cup: minimun 6-year follow-up. Arch Orthop Trauma Surg 2011;131:549-555.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17.

    Pipino FML , Molfetta L , Grandizio M . Preservation of the femoral neck in hip arthroplasty: results of a 13-17 year follow-up. J Orthop Traumatol 2000;1:31-39.

  • 18.

    Kendoff DO , Citak M , Egidy CC , O’Loughlin PF , Gehrke T . Eleven-year results of the anatomic coated CFP stem in primary total hip arthroplasty. J Arthroplasty 2013;28:1047-1051.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19.

    Kress AM , Schmidt R , Nowak TE et al.. Stress-related femoral cortical and cancellous bone density loss after collum femoris preserving uncemented total hip arthroplasty: a prospective 7-year follow-up with quantitative computed tomography. Arch Orthop Trauma Surg 2012;132:1111-1119.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20.

    Ghera S , Bisicchia S . The collum femoris preserving stem: early results. Hip Int 2013;23:27-32.

  • 21.

    Li M , Hu Y , Li K et al.. [Mid-term effectiveness of total hip arthroplasty with collum femoris preserving prosthesis]. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2012;26:897-901.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 22.

    Molfetta L , Capozzi M , Caldo D . Medium term follow up of the Biodynamic neck sparing prosthesis. Hip Int 2011;21:76-80.

  • 23.

    Briem D , Schneider M , Bogner N et al.. Mid-term results of 155 patients treated with a collum femoris preserving (CFP) short stem prosthesis. Int Orthop 2011;35:655-660.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24.

    Ding S , Zheng K . [Artificial total hip arthroplasty with collum femoris preserving for treating hip joint]. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi 2010;24:1-4.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 25.

    Shang XF , He R , Lu YF et al.. [Total hip replacement with collum femoris preserving for the treatment of advanced stage of femoral head necrosis of young patients: a report of results of more than five years follow-up]. Zhonghua Wai Ke Za Zhi 2010;48:1298-1300.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 26.

    Gill IR , Gill K , Jayasekera N , Miller J . Medium term results of the collum femoris preserving hydroxyapatite coated total hip replacement. Hip Int 2008;18:75-80.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 27.

    Röhrl SM , Li MG , Pedersen E , Ullmark G , Nivbrant B . Migration pattern of a short femoral neck preserving stem. Clin Orthop Relat Res 2006;448:73-78.

  • 28.

    Pons M . Learning curve and short-term results with a short-stem CFP system. Hip Int 2010;20(suppl 7):S52-S57.

  • 29.

    Pipino F . CFP prosthetic stem in mini-invasive total hip arthroplasty. J Orthop Traumatol 2004;5:165-171.

  • 30.

    You RJ , Zheng WZ , Chen K et al.. Long-term effectiveness of total hip replacement with the collum femoris preserving prosthesis. Cell Biochem Biophys 2015;72:43-47.

  • 31.

    Li M , Hu Y , Xie J . Analysis of the complications of the collum femoris preserving (CFP) prostheses. Acta Orthop Traumatol Turc 2014;48:623-627.

  • 32.

    Hutt J , Harb Z , Gill I et al.. Ten year results of the collum femoris preserving total hip replacement: a prospective cohort study of seventy five patients. Int Orthop 2014;38:917-922.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 33.

    Chammaï Y , Brax M . Medium-term comparison of results in obese patients and non-obese hip prostheses with Metha® short stem. Eur J Orthop Surg Traumatol 2015;25:503-508.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 34.

    Floerkemeier T , Tscheuschner N , Calliess T et al.. Cementless short stem hip arthroplasty METHA® as an encouraging option in adults with osteonecrosis of the femoral head. Arch Orthop Trauma Surg 2012;132:1125-1131.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 35.

    Thorey F , Hoefer C , Abdi-Tabari N et al.. Clinical results of the metha short hip stem: a perspective for younger patients? Orthop Rev (Pavia) 2013;5:e34.

  • 36.

    Wittenberg RH , Steffen R , Windhagen H , Bücking P , Wilcke A . Five-year results of a cementless short-hip-stem prosthesis. Orthop Rev (Pavia) 2013;5:e4.

  • 37.

    Schnurr C , Schellen B , Dargel J et al.. Low short-stem revision rates: 1-11 year results from 1888 total hip arthroplasties. J Arthroplasty 2017;32:487-493.

  • 38.

    Schmidutz F , Grote S , Pietschmann M et al.. Sports activity after short-stem hip arthroplasty. Am J Sports Med 2012;40:425-432.

  • 39.

    Shin YS , Suh DH , Park JH , Kim JL , Han SB . Comparison of specific femoral short stems and conventional-length stems in primary cementless total hip arthroplasty. Orthopedics 2016;39:e311-e317.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 40.

    Falez F , Casella F , Panegrossi G , Favetti F , Barresi C . Perspectives on metaphyseal conservative stems. J Orthop Traumatol 2008;9:49-54.

  • 41.

    Gagała J , Mazurkiewicz T . [Early experiences in the use of Mayo stem in hip arthroplasty]. Chir Narzadow Ruchu Ortop Pol 2009;74:152-156.

  • 42.

    Gilbert RE , Salehi-Bird S , Gallacher PD , Shaylor P . The Mayo Conservative Hip: experience from a district general hospital. Hip Int 2009;19:211-214.

  • 43.

    Zeh A , Weise A , Vasarhelyi A , Bach AG , Wohlrab D . [Medium-term results of the Mayo™ short-stem hip prosthesis after avascular necrosis of the femoral head]. Z Orthop Unfall 2011;149:200-205.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 44.

    Cruz-Vázquez FJ , De la , Rosa-Aguilar M , Gómez-López CA . [Evaluation of the uncemented Mayo femoral stem. The first 10 years]. Acta Ortop Mex 2011;25:108-113.

  • 45.

    Martins LG , Garcia FL , Picado CH . Aseptic loosening rate of the Mayo femoral stem with medium-term follow up. J Arthroplasty 2014;29:2122-2126.

  • 46.

    Arnholdt J , Gilbert F , Blank M et al.. The Mayo conservative hip: complication analysis and management of the first 41 cases performed at a University level 1 department. BMC Musculoskelet Disord 2017;18:250.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 47.

    Santori FS , Santori N . Mid-term results of a custom-made short proximal loading femoral component. J Bone Joint Surg [Br] 2010;92:1231-1237.

  • 48.

    Kim YH , Kim JS , Park JW , Joo JH . Total hip replacement with a short metaphyseal-fitting anatomical cementless femoral component in patients aged 70 years or older. J Bone Joint Surg [Br] 2011;93:587-592.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 49.

    Kim YH , Park JW , Kim JS . Is diaphyseal stem fixation necessary for primary total hip arthroplasty in patients with osteoporotic bone (Class C bone)? J Arthroplasty 2013;28:139-46.e1.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 50.

    Kim YH , Oh JH . A comparison of a conventional versus a short, anatomical metaphyseal-fitting cementless femoral stem in the treatment of patients with a fracture of the femoral neck. J Bone Joint Surg [Br] 2012;94:774-781.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 51.

    Kim YH , Kim JS , Joo JH , Park JW . A prospective short-term outcome study of a short metaphyseal fitting total hip arthroplasty. J Arthroplasty 2012;27:88-94.

  • 52.

    Tóth K , Mécs L , Kellermann P . Early experience with the Depuy Proxima short stem in total hip arthroplasty. Acta Orthop Belg 2010;76:613-618.

  • 53.

    Ghera S , Pavan L . The DePuy Proxima hip: a short stem for total hip arthroplasty. Early experience and technical considerations. Hip Int 2009;19:215-220.

  • 54.

    Malhotra R , Kumar V . Mid-term outcome of total hip arthroplasty using a short stem. J Orthop Surg (Hong Kong) 2016;24:323-327.

  • 55.

    Choi YW , Kim SG . The short-term clinical outcome of total hip arthroplasty using short metaphyseal loading femoral stem. Hip Pelvis 2016;28:82-89.

  • 56.

    Kim YH , Park JW , Kim JS . Ultrashort versus conventional anatomic cementless femoral stems in the same patients younger than 55 years. Clin Orthop Relat Res 2016;474:2008-2017.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 57.

    Henry BM , Wrażeń W , Hynnekleiv L et al.. Health-related quality-of-life and functional outcomes in short-stem versus standard-stem total hip arthroplasty: an 18-month follow-up cohort study. Med Sci Monit 2016;22:4406-4414.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 58.

    Kim YH , Park JW , Kim JS . Metaphyseal engaging short and ultra-short anatomic cementless stems in young and active patients. J Arthroplasty 2016;31:180-185.

  • 59.

    Kim YH , Park JW , Kim JS . Short-term results of ultra-short anatomic vs ultra-short non-anatomic proximal loading uncemented femoral stems. J Arthroplasty 2018;33:149-155.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 60.

    Ender SA , Machner A , Hubbe J , Pap G , Neumann HW . [Medium-term results of the cementless femoral neck prosthesis CUT]. Z Orthop Ihre Grenzgeb 2006;144:477-483.

  • 61.

    Ender SA , Machner A , Pap G , Grasshoff H , Neumann HW . [The femoral neck prosthesis CUT. Three- to six-year results]. Orthopade 2006;35:841-847.

  • 62.

    Ender SA , Machner A , Pap G et al.. Cementless CUT femoral neck prosthesis: increased rate of aseptic loosening after 5 years. Acta Orthop 2007;78:616-621.

  • 63.

    Steens W , Skripitz R , Schneeberger AG et al.. [Cementless femoral neck prosthesis CUT–clinical and radiological results after 5 years]. Z Orthop Unfall 2010;148:413-419.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 64.

    Rudert M , Leichtle U , Leichtle C , Thomas W . [Implantation technique for the CUT-type femoral neck endoprosthesis]. Oper Orthop Traumatol 2007;19:458-472.

  • 65.

    Thomas W , Lucente L , Mantegna N , Grundei H . [ESKA (CUT) endoprosthesis]. Orthopade 2004;33:1243-1248.

  • 66.

    Nieuwenhuijse MJ , Valstar ER , Nelissen RG . 5-year clinical and radiostereometric analysis (RSA) follow-up of 39 CUT femoral neck total hip prostheses in young osteoarthritis patients. Acta Orthop 2012;83:334-341.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 67.

    Ishaque BA , Gils J , Wienbeck S et al.. [Results after replacement of femoral neck prostheses - thrust plate prosthesis (TPP) versus ESKA cut prosthesis]. Z Orthop Unfall 2009;147:79-88.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 68.

    Stadler N , Lehner J , Abbas R , Trieb K . Prospective mid-term results of a consecutive series of a short stem. Acta Orthop Belg 2016;82:372-375.

  • 69.

    Ettinger M , Ettinger P , Lerch M et al.. The NANOS short stem in total hip arthroplasty: a mid term follow-up. Hip Int 2011;21:583-586.

  • 70.

    Capone A , Bienati F , Torchia S , Podda D , Marongiu G . Short stem total hip arthroplasty for osteonecrosis of the femoral head in patients 60 years or younger: a 3- to 10-year follow-up study. BMC Musculoskelet Disord 2017;18:301.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 71.

    Sperati G , Ceri L . Total hip arthroplasty using TRI-LOCK® DePuy bone preservation femoral stem: our experience. Acta Biomed 2014;85(suppl 2):66-70.

  • 72.

    Albers A , Aoude AA , Zukor DJ et al.. Favorable results of a short, tapered, highly porous, proximally coated cementless femoral stem at a minimum 4-year follow-up. J Arthroplasty 2016;31:824-829.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 73.

    Amendola RL , Goetz DD , Liu SS , Callaghan JJ . Two- to 4-year followup of a short stem THA construct: excellent fixation, thigh pain a concern. Clin Orthop Relat Res 2017;475:375-383.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 74.

    Morales de Cano JJ , Gordo C , Illobre JM . Early clinical results of a new conservative hip stem. Eur J Orthop Surg Traumatol 2014;24:359-363.

  • 75.

    Morales de Cano JJ , Gordo C , Canosa Areste J . Short femoral stem in total hip arthroplasty: stable fixation and low complication rates in elderly patients. Hip Int 2017;27:311-316.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 76.

    Gustke K . Short stems for total hip arthroplasty: initial experience with the Fitmore stem. J Bone Joint Surg [Br] 2012;94 (suppl A):47-51.

  • 77.

    Hurschler C , Seehaus F , Emmerich J , Kaptein BL , Windhagen H . Accuracy of model-based RSA contour reduction in a typical clinical application. Clin Orthop Relat Res 2008;466:1978-1986.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 78.

    Kärrholm J , Herberts P , Hultmark P et al.. Radiostereometry of hip prostheses. Review of methodology and clinical results. Clin Orthop Relat Res 1997;(344):94-110.

  • 79.

    Kärrholm J . Radiostereometric analysis of early implant migration - a valuable tool to ensure proper introduction of new implants. Acta Orthop 2012;83:551-552.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 80.

    Acklin YP , Jenni R , Bereiter H , Thalmann C , Stoffel K . Prospective clinical and radiostereometric analysis of the Fitmore short-stem total hip arthroplasty. Arch Orthop Trauma Surg 2016;136:277-284.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 81.

    Budde S , Seehaus F , Schwarze M et al.. Analysis of migration of the Nanos® short-stem hip implant within two years after surgery. Int Orthop 2016;40:1607-1614.

  • 82.

    McCalden RW , Korczak A , Somerville L , Yuan X , Naudie DD . A randomised trial comparing a short and a standard-length metaphyseal engaging cementless femoral stem using radiostereometric analysis. Bone Joint J 2015;97-B:595-602.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 83.

    Mahmoud AN , Kesteris U , Flivik G . Stable migration pattern of an ultra-short anatomical uncemented hip stem: a prospective study with 2 years radiostereometric analysis follow-up. Hip Int 2017;27:259-266.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 84.

    Biedermann R , Krismer M , Stöckl B et al.. Accuracy of EBRA-FCA in the measurement of migration of femoral components of total hip replacement. Einzel-Bild-Röntgen-Analyse-femoral component analysis. J Bone Joint Surg [Br] 1999;81:266-272.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 85.

    Krismer M , Biedermann R , Stöckl B et al.. The prediction of failure of the stem in THR by measurement of early migration using EBRA-FCA. Einzel-Bild-Roentgen-Analyse-femoral component analysis. J Bone Joint Surg [Br] 1999;81:273-280.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 86.

    Schmidutz F , Graf T , Mazoochian F et al.. Migration analysis of a metaphyseal anchored short-stem hip prosthesis. Acta Orthop 2012;83:360-365.

  • 87.

    Kutzner KP , Kovacevic MP , Freitag T et al.. Influence of patient-related characteristics on early migration in calcar-guided short-stem total hip arthroplasty: a 2-year migration analysis using EBRA-FCA. J Orthop Surg Res 2016;11:29.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 88.

    Kutzner KP , Freitag T , Donner S , Kovacevic MP , Bieger