Cemented compared to uncemented femoral stems in total hip replacement for displaced femoral neck fractures in the elderly: study protocol for a single-blinded, randomized controlled trial (CHANCE-trial).

BACKGROUND: Total hip replacement (THR) is the preferred method for the active and lucid elderly patient with a displaced femoral neck fracture (FNF). But controversy still exists regarding using cemented or uncemented stem in these patients. The aim of this study is to compare a cemented and uncemented femoral stem in patients 65-79 years treated surgically with THR for displaced FNF. METHODS/DESIGN: In a single-centre, single-blinded, randomized controlled trial, we will include 140 patients aged 65-79 years with an acute displaced FNF and randomize them in a 1:1 ratio to a cemented tapered or a uncemented tapered hydroxyapatite - coated femoral stem. A cemented cup will be used in both groups. The patients will be blinded for allocation. The primary endpoints will be the incidence of all hip-related complications and health-related quality of life evaluated with EuroQol-5D (EQ-5D) index up to 2 years after surgery. Secondary outcomes will be overall mortality, general medical complications and hip function. The follow-up will be at 3 months, 1 and 2 years. Further follow-ups after end of study will be at 4 and 10 years. Results will be analysed using 95 % CI's for the effect size. A regression model will also be used to adjust for stratification factor. DISCUSSION: The ethical committee at Karolinska Institutet has approved the study. An interim analysis on the primary endpoints will be performed when half the sample size is included. The results from the study will be disseminated to the medical community via presentations and publications in relevant medical journals. The study will provide evidence if a cemented or uncemented femoral stem is preferable in THR for elderly patients with a displaced FNF. TRIAL REGISTRATION: The trial is registered at clinicaltrials.gov ( NCT02247791 ), October 21, 2013.

Denosumab for treating periprosthetic osteolysis; study protocol for a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Wear-induced osteolysis is the main factor in reducing the longevity of total hip arthroplasty (THA). The transmembrane Receptor Activator of Nuclear Factor κ B (RANK) and its corresponding ligand RANKL is an important regulator of osteoclast activity and bone resorption and is associated with osteolysis around implant. Inhibiting RANKL with denosumab is effective in vivo in preventing osteoporosis-related fractures. In vitro, osteoclasts can be blocked in animal models of osteolysis. We hypothesize that denosumab is effective in reducing wear-induced osteolysis around uncemented acetabular implants in THA. METHODS/DESIGN: A randomized, double-blind, placebo-controlled trial will be conducted. We will include 110 patients, 40-85 years of age, with a known osteolytic lesion around an uncemented acetabular component ≥7 years after the primary operation. The patients will be randomized in a 1:1 ratio to subcutaneous injections of 60 mg denosumab or placebo for a total of 6 doses with start on day one and every 6 months with last treatment at 30 months. The primary endpoint will be the change in volume of the osteolytic lesion at 3 years measured with three-dimensional computed tomography (3D-CT). Secondary endpoints include functional outcome scores, change in bone mineral density of the lumbar spine, serological markers of bone turnover and adverse events. DISCUSSION: In vitro results of both bisphosphonates and RANKL inhibitors have been promising, showing reduced osteolysis with treatment. This is, to our knowledge, the first clinical trial testing the efficacy of denosumab in reducing wear-induced osteolysis. The study is an academic, phase II trial from an independent center and is designed to demonstrate efficacy in reducing volume of osteolytic lesions around a total hip arthroplasty. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02299817) 2014-11-20.

HOPE-trial: hemiarthroplasty compared to total hip arthroplasty for displaced femoral neck fractures in the elderly-elderly, a randomized controlled trial.

BACKGROUND: A femoral neck fracture (FNF) is a common cause of suffering and premature death in the elderly population. Optimizing the treatment for improved outcome and a reduced need for secondary surgery is important both for the patient and the society. The choice of primary total or hemiarthroplasty in patients over eighty years are controversial. We hypothesized that total hip arthroplasty has an equal or better outcome in patient-reported outcome compared with hemiarthroplasty. METHODS/DESIGN: A prospective, randomized, single-blinded trial will be conducted. We will include 120 patients, 80 years of age and over with an acute (<36 h) displaced femoral neck fracture. The patients will be randomized in a 1:1 ratio to either total hip arthroplasty or hemiarthroplasty. The primary endpoints are Harris hip Score and EQ-5D. Secondary endpoints include pain measured with visual analogue scale, surgical time, reoperations, complications and radiological measurement of erosion in patients operated with hemiarthroplasty. Follow-up will be performed postoperatively after three months, 1, 2, 4 and 10 years. DISCUSSION: To our knowledge, this is the first randomized controlled trial comparing total hip arthroplasty and hemiarthroplasty for displaced femoral neck fracture in patients age 80 years and over. TRIAL REGISTRATION: Clinicaltrial.gov: NCT02246335.

Porous titanium construct cup compared to porous coated titanium cup in total hip arthroplasty. A randomised controlled trial.

PURPOSE: The purpose of this study was to determine if a new titanium cup with increased porosity resulted in different periacetabular bone loss and migration compared to a porous coated cup. METHODS: Fifty-one patients with primary hip osteoarthritis were randomized to either a cup with porous titanium construct backside (porous titanium group, n = 25) or a conventional porous coated titanium cup (control group, n = 26). The primary outcome variable was change in periacetabular bone mineral density two years after surgery measured with dual energy X-ray absorptiometry (DXA). Secondary outcomes were implant fixation measured with radiostereometry (RSA) and clinical outcome scores. RESULTS: The pattern of bone remodelling was similar in the two groups with almost complete restoration to baseline values. BMD diminished in the two proximal zones and increased in the two distal zones. After minimal migration up to six months all implants in both groups became stable. We found no difference between the two groups in clinical outcome scores. CONCLUSIONS: In this prospective, randomized, controlled trial on a new porous titanium cup we found, compared to the control group, no clinically relevant differences regarding periacetabular bone preservation, implant fixation or clinical outcome up to two years postoperatively.

Vitamin-E diffused highly cross-linked polyethylene liner compared to standard liners in total hip arthroplasty. A randomized, controlled trial.

PURPOSE: We hypothesized that a vitamin E-treated polyethylene articulating liner had lower femoral head penetration than a conventional liner. METHODS: Fifty-one patients with primary hip osteoarthritis were randomized to an uncemented cup with either vitamin E-treated highly cross-linked polyethylene (HXLPE) (vitamin-e group, n = 25) or a standard HXLPE liner (control group, n = 26) and followed for two years after surgery. The outcome variable was polyethylene (PE) linear head penetration, measured with radiostereometry (RSA). RESULTS: The head penetration in x- (medial/lateral) and y- (vertical) axes was significantly lower for the vitamin E-treated liner up to two years with a mean difference between the groups of 0.10 mm (95 % CI 0.04-0.18) and 0.08 mm (95 % CI 0.01-0.15), respectively. The initial total penetration was lower for the vitamin-E group but did not reach statistical significance at two years with a mean difference between the groups of 0.07 mm (95 % CI -0.001 to 0.15, p = 0.09). We found no differences in clinical outcome between the groups. CONCLUSIONS: In this prospective, randomized, controlled trial on a new vitamin-E diffused HXLPE liner we found, compared to a conventional HXLPE liner, lower initial head penetration and lower superior and medial wear. A longer follow-up than two years is necessary to demonstrate lower overall head penetration in vitamin-E liners compared to contemporary highly cross-linked PE.

Lower periprosthetic bone loss and good fixation of an ultra-short stem compared to a conventional stem in uncemented total hip arthroplasty.

BACKGROUND AND PURPOSE: We hypothesized that an ultra-short stem would load the proximal femur in a more physiological way and could therefore reduce the adaptive periprosthetic bone loss known as stress shielding. PATIENTS AND METHODS: 51 patients with primary hip osteoarthritis were randomized to total hip arthroplasty (THA) with either an ultra-short stem or a conventional tapered stem. The primary endpoint was change in periprosthetic bone mineral density (BMD), measured with dual-energy x-ray absorptiometry (DXA), in Gruen zones 1 and 7, two years after surgery. Secondary endpoints were change in periprosthetic BMD in the entire periprosthetic region, i.e. Gruen zones 1 through 7, stem migration measured with radiostereometric analysis (RSA), and function measured with self-administered functional scores. RESULTS: The periprosthetic decrease in BMD was statistically significantly lower with the ultra-short stem. In Gruen zone 1, the mean difference was 18% (95% CI: -27% to -10%). In zone 7, the difference was 5% (CI: -12% to -3%) and for Gruen zones 1-7 the difference was also 5% (CI: -9% to -2%). During the first 6 weeks postoperatively, the ultra-short stems migrated 0.77 mm more on average than the conventional stems. 3 months after surgery, no further migration was seen. The functional scores improved during the study and were similar in the 2 groups. INTERPRETATION: Up to 2 years after total hip arthroplasty, compared to the conventional tapered stem the ultra-short uncemented anatomical stem induced lower periprosthetic bone loss and had equally excellent stem fixation and clinical outcome.

No effect of risedronate on femoral periprosthetic bone loss following total hip arthroplasty. A 4-year follow-up of 61 patients in a double-blind, randomized placebo-controlled trial.

BACKGROUND AND PURPOSE: We have previously shown that during the first 2 years after total hip arthroplasty (THA), periprosthetic bone resorption can be prevented by 6 months of risedronate therapy. This follow-up study investigated this effect at 4 years. PATIENTS AND METHODS: A single-center, double-blind, randomized placebo-controlled trial was carried out from 2006 to 2010 in 73 patients with osteoarthritis of the hip who were scheduled to undergo THA. The patients were randomly assigned to receive either 35 mg risedronate or placebo orally, once a week, for 6 months postoperatively. The primary outcome was the percentage change in bone mineral density (BMD) in Gruen zones 1 and 7 in the proximal part of the femur at follow-up. Secondary outcomes included migration of the femoral stem and clinical outcome scores. RESULTS: 61 of the 73 patients participated in this 4-year (3.9- to 4.1-year) follow-up study. BMD was similar in the risedronate group (n = 30) and the placebo group (n = 31). The mean difference was -1.8% in zone 1 and 0.5% in zone 7. Migration of the femoral stem, the clinical outcome, and the frequency of adverse events were similar in the 2 groups. INTERPRETATION: Although risedronate prevents periprosthetic bone loss postoperatively, a decrease in periprosthetic BMD accelerates when therapy is discontinued, and no effect is seen at 4 years. We do not recommend the use of risedronate following THA for osteoarthritis of the hip.

Reduced dislocation rate after hip arthroplasty for femoral neck fractures when changing from posterolateral to anterolateral approach.

BACKGROUND AND PURPOSE: Recent studies have shown that compared to the posterolateral approach, the anterolateral approach reduces the risk of dislocation after hip arthroplasty in patients with femoral neck fractures. We have therefore started to use the anterolateral approach on these patients and we now report the consequences of this change for the dislocation rate. PATIENTS AND METHODS: We chose two 1-year time periods, 2007 (n = 199) and 2008 (n = 173), the former being before and the latter after the implementation of the anterolateral approach as the standard incision for hip arthroplasties in patients with femoral neck fractures. During 2007, 77% of the hips were operated on with the posterolateral approach and in 2008, 78% of the hips were operated on using the anterolateral approach. RESULTS: The dislocation rate was reduced from 8% (16/199) in 2007 to 2% (3/173) in 2008. A multivariable logistic regression analysis showed that the posterolateral approach was the only factor associated with an increased risk of dislocation, with an odds ratio of 8 (2­35). Age, sex, ASA classification, type of arthroplasty, cognitive dysfunction, or the experience of the surgeon had no effect on the risk of dislocation. INTERPRETATION: Since most of our surgeons had earlier used the posterolateral approach when performing hip arthroplasties in patients with a femoral neck fracture, this study shows our surgical learning curve. We conclude that a collective policy change regarding surgical approach for these patients is both feasible and to be recommended, as it leads to a substantial reduction in dislocation rate.

Large femoral bone loss after hip revision using the uncemented proximally porous-coated Bi-Metric prosthesis: 22 hips followed for a mean of 6 years.

BACKGROUND AND PURPOSE: Periprosthetic bone loss after uncemented femoral hip revision is a matter of concern. We have used a proximally porous- and hydroxyapatite-coated prosthesis (Bi-Metric) in revision since 1989 and now we report the bone changes. This prosthesis is intended to distribute the forces more evenly and to avoid proximal femoral unloading. METHODS: 22 patients were unilaterally reoperated because of aseptic loosening. Only patients with a healthy contralateral hip were included. Mean age at revision was 69 (55-80) years. Bone defects were graded by Gustilo-Pasternak and Endo-Klinik classifications. Clinical assessment was performed with Harris hip score. We used radiographs and dual-energy X-ray absorptiometry to evaluate migration, femoral remodeling, and bone mineral density after 72 (30-158) months. RESULTS: The mean Harris hip score was 74 (30-100) points at follow-up. Mild thigh discomfort was present in 1 patient and moderate thigh pain in 3 patients. There was no loosening or subsidence. Osteolysis seen at revision had diminished in 19 of the 22 hips at follow-up. We noted a large reduction in bone mineral density. It was most pronounced in Gruen regions 1, 2, 6, and 7. INTERPRETATION: Revision with this stem is a reliable procedure; however, we noted a large degree of proximal bone loss that could lead to later mechanical complications or fractures.

A randomized double-blind noninferiority trial, evaluating migration of a cemented vitamin E-stabilized highly crosslinked component compared with a standard polyethylene component in reverse hybrid total hip arthroplasty.

AIMS: Radiostereometric analysis (RSA) studies of vitamin E-doped, highly crosslinked polyethylene (VEPE) liners show low head penetration rates in cementless acetabular components. There is, however, currently no data on cemented VEPE acetabular components in total hip arthroplasty (THA). The aim of this study was to evaluate the safety of a new cemented VEPE component, compared with a conventional polyethylene (PE) component regarding migration, head penetration, and clinical results. PATIENTS AND METHODS: We enrolled 42 patients (21 male, 21 female) with osteoarthritis and a mean age of 67 years (sd 5), in a double-blinded, noninferiority, randomized controlled trial. The subjects were randomized in a 1:1 ratio to receive a reverse hybrid THA with a cemented component of either argon-gas gamma-sterilized PE component (controls) or VEPE, with identical geometry. The primary endpoint was proximal implant migration of the component at two years postoperatively measured with RSA. Secondary endpoints included total migration of the component, penetration of the femoral head into the component, and patient-reported outcome measurements. RESULTS: In total, 19 control implants and 18 implants in the VEPE group were analyzed for the primary endpoint. We found a continuous proximal migration of the component in the VEPE group that was significantly higher with a difference at two years of a mean 0.21 mm (95% confidence interval (CI) 0.05 to 0.37; p = 0.013). The total migration was also significantly higher in the VEPE group, but femoral head penetration was lower. We found no difference in clinical outcomes between the groups. CONCLUSION: At two years, this cemented VEPE component, although having a low head penetration and excellent clinical results, failed to meet noninferiority compared with the conventional implant by a proximal migration above the proposed safety threshold of RSA. The early proximal migration pattern of the VEPE component is a reason for continued monitoring, although a specific threshold for proximal migration and risk for later failure cannot be defined and needs further study. Cite this article: Bone Joint J 2019;101-B:1192-1198.

Good results with an uncemented proximally HA-coated stem in hip revision surgery: 62 hips followed for 2-13 years.

BACKGROUND AND PURPOSE: Proximal bone loss due to stress-shielding is a matter of concern after uncemented femoral hip revision. We have used short, proximally hydroxyapatite-coated prostheses in revision since 1989, and we now report the results. METHODS: 60 patients (62 hips) were revised because of aseptic loosening. Bone defects prior to revision were mostly of type II according to the Gustilo-Pasternak and Endo-Klinik classifications. Follow-up time was 73 (24-161) months. 9 patients had died before follow-up; 8 of these still had the stem in place. Clinical assessment was performed with the Harris hip score. Radiographs were evaluated for bone defects at revision, postoperative stem fixation, and periprosthetic bone remodeling. RESULTS: Mean Harris hip score was 75 (30-100) points. There was no stem loosening or progressive subsidence. 8 patients had mild to moderate thigh pain. Osteolysis, present at revision, had diminished, partially or completely, in four-fifths of the hips at follow-up. 4 hips had required re-revision due to fracture or dislocation. The 6-year prosthesis survival rate was 95% (95% CI: 0.83-0.98). INTERPRETATION: Uncemented revision with a short, proximally hydroxyapatite-coated prosthesis is a reliable procedure with encouraging results in the medium term if bone defects at revision are moderate.

Migration and head penetration of Vitamin-E diffused cemented polyethylene cup compared to standard cemented cup in total hip arthroplasty: study protocol for a randomised, double-blind, controlled trial (E1 HIP).

INTRODUCTION: In vitro, Vitamin-E-diffused, highly cross-linked polyethylene (PE) has been shown to have superior wear resistance and improved mechanical properties when compared to those of standard highly cross-linked PE liners used in total hip arthroplasty (THA). The aim of the study is to evaluate the safety of a new cemented acetabular cup with Vitamin-E-doped PE regarding migration, head penetration and clinical results. METHODS AND ANALYSIS: In this single-centre, double-blinded, randomised controlled trial, we will include 50 patients with primary hip osteoarthritis scheduled for THA and randomise them in a 1:1 ratio to a cemented cup with either argon gas-sterilised PE (control group) or Vitamin-E-diffused PE (vitamin-e group). All patients and the assessor of the primary outcome will be blinded and the same uncemented stem will be used for all participants. The primary end point will be proximal migration of the cup at 2 years after surgery measured with radiostereometry. Secondary end points include proximal migration at other follow-ups, total migration, femoral head penetration, clinical outcome scores and hip-related complications. Patients will be followed up at 3 months and at 1, 2, 5 and 10 years postoperatively. RESULTS: Results will be analysed using 95% CIs for the effect size. A regression model will also be used to adjust for stratification factors. ETHICS AND DISSEMINATION: The ethical committee at Karolinska Institutet has approved the study. The first results from the study will be disseminated to the medical community via presentations and publications in relevant medical journals when the last patient included has been followed up for 2 years. TRIAL REGISTRATION NUMBER: NCT02254980.

Larger femoral periprosthetic bone mineral density decrease following total hip arthroplasty for femoral neck fracture than for osteoarthritis: a prospective, observational cohort study.

Studies on patients with degenerative joint disease of the hip show that femoral periprosthetic bone mineral decreases following total hip arthroplasty. Scarcely any osteodensitometric data exist on femoral neck fracture (FNF) patients and periprosthetic bone remodelling. In two parallel cohorts we enrolled 87 patients (mean age, 72 ± 12 years; male:female ratio, 30:57) undergoing total hip arthroplasty for either primary osteoarthritis (OA) of the hip (n = 37) or for an acute FNF (n = 50) and followed them for a mean of 5.4 years. Outcomes were bone mineral density (BMD) changes in the periprosthetic Gruen zones 1-7, the incidence of periprosthetic fractures and clinical outcome. The bone mineral loss in the fracture group was more than twice that of the osteoarthritis group, -16.9% versus -6.8% (p = 0.004). The incidence of periprosthetic fractures was 12% (6/50) in the fracture cohort compared with none (0%) in the OA cohort (p = 0.03). Periprosthetic bone mineral loss following total hip arthroplasty is significantly greater in patients who are treated for acute FNF than in OA patients. This decrease of BMD follows a different pattern with the FNF patients losing larger proportions of bone in Gruen zones 1, 2, 6, and 7 while the OA patients tend to have larger losses only in zones 1 and 7.

The effect of weekly risedronate on periprosthetic bone resorption following total hip arthroplasty: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Bone loss leading to late-occurring periprosthetic femoral fracture is a mode of failure in cementless total hip arthroplasty. The aim of this trial was to investigate the effect of a bisphosphonate, risedronate, on femoral periprosthetic bone resorption following total hip arthroplasty in patients with osteoarthritis of the hip. METHODS: We enrolled seventy-three patients between the ages of forty and seventy years who were scheduled to undergo total hip arthroplasty in a single-center, randomized, double-blind, placebo-controlled trial. Subjects were randomly assigned to receive either 35 mg of risedronate (n = 36) or a placebo (n = 37) orally once weekly for six months. The primary end point was the change in bone mineral density in Gruen femoral zones 1 and 7. Bone mineral density scans were made preoperatively and at two days and three, six, twelve, and twenty-four months postoperatively. Secondary end points included migration of the femoral stem and clinical outcome. RESULTS: Seventy of the seventy-three patients (thirty-three in the risedronate group and thirty-seven in the placebo group) were analyzed for the primary end point. The mean bone mineral density in zone 1 was 9.2% higher (95% confidence interval [CI], 4.2% to 14.1%) in the risedronate group than in the placebo group at six months postoperatively and 7.2% higher (95% CI, 1.0% to 13.3%) at one year. The mean bone mineral density in zone 7 was 8.0% higher (95% CI, 2.7% to 13.4%) in the risedronate group than in the placebo group at six months postoperatively and 4.3% higher (95% CI, -1.5% to 10.1%) at one year. Migration of the femoral stem, the clinical outcome, and the frequency of adverse events did not differ between the groups. CONCLUSIONS: Risedronate taken once weekly for six months following total hip arthroplasty was effective in reducing periprosthetic bone resorption around an uncemented femoral stem up to one year after surgery but had no discernible effect on implant migration or clinical outcome. Future studies of bisphosphonate treatment following total hip arthroplasty should focus on clinically relevant end points such as the risks of fracture and revision arthroplasty.

Total hip arthroplasty with an uncemented hydroxyapatite-coated tapered titanium stem: results at a minimum of 10 years' follow-up in 104 hips.

BACKGROUND: The purpose of this study was to evaluate the minimum 10-year results of primary total hip arthroplasty using an uncemented, hydroxyapatite-coated tapered stem. Radiological signs of bone remodeling are also presented. METHODS: We followed a consecutive series of 105 patients (115 hips), who had had an uncemented, proximally hydroxyapatite-coated Bi-Metric femoral component for a mean of 12.2 years (range 10.0-14.9 years). The average age at operation was 52 years. Detailed clinical and radiological analyses were performed after a minimum of 5 and 10 years. Eight patients (10 hips) had died, and one patient was lost to follow-up, leaving 104 hips for final evaluation. The clinical result was evaluated by the Harris Hip Score, complications, and thigh pain. RESULTS: All patients still had their femoral components in place at the final follow-up. The average Harris Hip Score after 10 years was 92 (range 50-100) with no deterioration over time. Radiologically, several signs of progressive remodeling were identified, but no stem showed signs of loosening. CONCLUSIONS: The intermediate clinical and radiological results with this stem are encouraging. In the hands of various surgeons, the stem has performed well in a young, high-risk population.

Periprosthetic proximal bone loss after uncemented hip arthroplasty is related to stem size: DXA measurements in 138 patients followed for 2-7 years.

BACKGROUND: Periprosthetic bone loss occurs around uncemented femoral stems and may be influenced by the stem size. PATIENTS AND METHODS: We studied 138 consecutive patients, 3 (2-7) years on average after a total hip arthroplasty operation (THA) for unilateral osteoarthritis with the Bi-Metric uncemented femoral stem. We analyzed Harris hip score and bone mineral density. RESULTS: The mean Harris hip score was 97 at follow-up. Bone mineral density decreased proximally by 19% in both Gruen zones 1 and 7. Bone loss in zones 1, 2, 6, and 7 was significantly associated with stem size. Distally, a small gain in bone mass was found in zones 3 and 5 for medium femoral sizes. INTERPRETATION: We found a marked proximal BMD loss, especially for the larger stems, which may be specific for this particular implant. Long-term studies should reveal whether this proximal bone loss will affect the longevity of the THA.

Continuous bone loss around a tapered uncemented femoral stem: a long-term evaluation with DEXA.

BACKGROUND: Periprosthetic bone loss is a well-documented phenomenon after uncemented total hip arthroplasty (THA); however, little is known about how bone mineral density (BMD) changes after 2 years. PATIENTS AND METHODS: 14 patients with hip arthrosis (group A) were operated with a proximally porous- and hydroxyapatite-coated stem and followed for 10 years with DEXA, radiographs and Harris hip score (HHS). Another group of 14 patients (group B) was evaluated at 6 and 14 years using the same prosthesis and protocol. RESULTS: No stem was revised and all stems were well-Fixed. At final follow-up, HHS was 97 points in group A after 10 years and 94 points in group B after 14 years. Bone mineral changes in group A were greatest in Gruen zones 1 and 7, where the losses were 31% and 26%, respectively, after 2 years on the operated side. The decrease in BMD continued after 2 years and in Gruen zone 7 it was faster than the rate of bone loss on the control side. In group B, the annual change in BMD on the operated side was not significantly different from the bone loss in group A. INTERPRETATION: Up to 14 years after implantation of a tapered uncemented stem, the BMD in the calcar region continues to decrease faster than would be expected from normal ageing.