Primary total hip arthroplasty with an uncemented femoral component: two- to seven-year results

RADIOGRAPHIC EVALUATION OF OSSEOINTEGRATION OF UNCEMENTED TARGOS® STEMS. A 5-YEAR FOLLOW-UP

Introduction

Total hip arthroplasty is a widespread treatment and is considered the gold standard in cases of hip osteoarthritis, with high rates of success in improving pain and function when well performed. After five years of follow-up, this study evaluates the osseointegration of uncemented Targos® collared stems in arthroplasties.

Methods

Observational study of 182 total hip arthroplasties performed in 2014 with Targos® cementless collared femoral stems (Lepine). Bone quality was assessed according to the Dorr scale and osseointegration according to the Engh score.

Results

The overall mean age was 56.5 years, consisting of 104 men (57.1%) and 103 women (56.6%). The osseointegration rate of the stems (total Engh>0) was 100%. There was no statistical difference between groups concerning age (p=0.262), gender (p=0.463), primary diagnosis (p=0.585), affected side (p=0.459), and degree of Dorr (p=0.857).

Conclusion

Targos® cementless collared femoral stems showed excellent osseointegration in all patients evaluated, regardless of age, gender, and preoperative bone quality. Moreover, spot welds observed on preoperative radiographs have the best association with implant osseointegration. Level of evidence IV, case series .

Femoral prosthesis neck fracture following total hip arthroplasty - a systematic review

PURPOSE

Head-neck modularity was introduced into total hip arthroplasty to provide more intraoperative surgical options. However, modularity led to new problems, such as trunnionosis and fractures of the femoral prosthesis neck. The purpose of this study was to identify risk factors for hip neck fractures and to provide recommendations to prevent damage and fractures of the neck.

METHODS

A systematic review of the literature was performed according to the PRISMA guidelines.

RESULTS

Thirty-three case studies were included. Methodologically, most included studies were of moderate or good quality. The 80 neck fractures included in the review took place, on average, 7 years after stem placement. Male gender, high body weight, obesity, previous revision surgery, mixing components from different manufacturers, use of long skirted heads, cobalt-chromium (large size) heads were identified as potential risk factors.

CONCLUSION

Hip neck fractures occur on average 7 years after stem placement. The etiology of hip neck fractures is multifactorial. This review revealed several preventable implant- and surgeon-related risk factors.

The Effect of Hot Working on the Mechanical Properties of High Strength Biomedical Ti-Nb-Ta-Zr-O Alloy

Beta titanium alloy Ti-35Nb-6Ta-7Zr-0.7O (wt%) was developed as a material intended for the manufacturing of a stem of a hip joint replacement. This alloy contains only biocompatible elements and possesses a very high yield strength already in the cast condition (900 MPa). However, the porosity, large grain size and chemical inhomogeneity reduce the fatigue performance below the limits required for utilization in the desired application. Two methods of hot working, die forging and hot rolling, were used for processing of this alloy. Microstructural evolution, tensile properties and fatigue performance of the hot worked material were investigated and compared to the cast material. Microstructural observations revealed that porosity is removed in all hot-worked conditions and the grain size is significantly reduced when the area reduction exceeds 70%. Static tensile properties were improved by both processing methods and ultimate tensile strength (UTS) of 1200 MPa was achieved. Fatigue results were more reproducible in the hot rolled material due to better microstructural homogeneity, but forging leads to an improved fatigue performance. Fatigue limit of 400 MPa was achieved in the die-forged condition after 70% of area reduction and in the hot rolled condition after 86% of area reduction.

Functional and radiological outcome of uncemented total hip arthroplasty in young adults - 5 year follow-upollow-up

Background

End stage arthritis in young patients requires surgical intervention. THA remains the treatment of choice for restoring function and activity in end stage hip arthritis. The medium term outcome of uncemented THA in Indian population is less studied. Hence this study was taken up with aim to study clinical and radiological outcome of uncemented THA in patients with age less than 40 years.

Methods

This study was conducted during January 2013 to December 2013. Overall 66 patients with 74 arthritic hips were operated by single surgeon (1st Author) with Uncemented THA. All patients were either unilateral or bilateral arthritis of hip less than 40 years of age. Patients were evaluated preoperatively and postoperatively. After discharge patients were followed up at regular intervals. Activity level and Harris Hip score was calculated. Radiological evaluation was done with anteroposterior and lateral X-rays.

Results

Total 50 patients (56 hips) followed up at five year follow-up. Clinical and radiological evaluation was done during follow-up. Most common etiology was avascular necrosis of hip (56.6%). None of the patients had any major complications. Mean Harris Hip score improved from 36 to 92. The activity level was assessed at five year follow-up with maximum patients in moderate manual labor category. Bony ingrowth with no evidence of loosening was seen consistently both on femoral and acetabular side in all patients on X-ray. No statistically significant association was found between initial alignment of the femoral component and clinical outcome.

Conclusion

Uncemented THA can be used in young patients with excellent to good functional and radiological outcome at midterm follow-up, high satisfaction rate and lower rate of complications.

The Accolade TMZF stem fulfils the demands of modern stem design: Minimum 5-year survival in a cohort of 937 patients

PURPOSE

Modern hip stem design includes a prosthesis that has a predictable outcome in all total hip arthroplasty (THA) patients, regardless of approach, surgeon or patient characteristics. Introduction without a learning curve and, in cases of problems, the possibility for a simple revision are other prerequisites. The purpose of this study is to evaluate whether the Accolade TMZF stem (Stryker Orthopedics, Mahwah, New Jersey, USA) is suitable to fulfil these demands. We report our mid-term survival of the Accolade TMZF hip stem in all patients from the first implantation at our institute.

METHODS

From the start of using the Accolade TMZF stem (March 2009) until February 2011, 937 THA were performed by 12 surgeons using a posterolateral or anterolateral approach. Survival of the stem was calculated using Kaplan-Meier analysis. Effect of approach, patient age and comorbidity were analysed with a Cox proportional hazards' model. The learning effect was determined by comparing the number of revisions in the surgeons' first 20 THAs with their next 30 THAs and the subsequent THAs.

RESULTS

At 5 years, cumulative stem survival was 97.9% based on revisions for all reasons and 98.8% with aseptic loosening as endpoint. We found no effect of surgical approach, patient age or comorbidity on stem survival. No learning effect was found.

CONCLUSION

The Accolade TMZF stem fulfilled the demands of modern stem design.

Total hip arthroplasty with accolade/trident through the direct minimally invasive anterior approach without traction table: Learning curve and results after a minimum of 5 years

BACKGROUND

The direct minimally invasive anterior approach (DMIAA) in total hip arthroplasty (THA) is widely accepted. In our department the DMIAA according to Rachbauer together with the Trident cup and Accolade stem was introduced in 2004. The purpose of the study was to demonstrate the five-year results and to analyze the learning curve of a new introduced approach.

PATIENTS AND METHODS

Between July 2004 and May 2006, a consecutive series of 151 THA in 147 patients was retrospectively analyzed. All patients were planned to received a THA with the Accolade/Trident implant system using the DMIAA without traction table. Clinical and radiographic data, complications and survivorship were documented with a follow-up of at least 5 years.

RESULTS

Regarding cup implantation, there were 11 (7.3%) failed intentions to treat due to missing pressfit (8 cases) and acetabular floor perforation (3 cases). No failed intentions to treat occurred during stem implantation. Total implant survival after 5 years follow-up after exclusion of 11 cases with failed intention to treat (N=140) was 96.9% (SD 1.4; CI 94.3-99.6). After exclusion of the failed intentions to treat (N=140, N=4 in the first 20 cases), there was significant (p<0.001) difference between the first 16 implants with a 5 year-survival of 83.2% (SD 8.6; CI 66.4-100) and 95.7% (SD 0.9; CI 93.9-97.5) for the following 124 implants. Radiolucent lines were observed in Gruen zone 1 in 3.3% and in Gruen zone 1 and 2 in 1.1%.

DISCUSSION

THA with Accolade/Trident using the DMIAA without traction table according to Rachbauer temporary exposed patients to a higher risk of implant revisions, which was normalized after the first 20 cases. Results of the learning curve are comparable to other techniques using an orthopaedic traction table. After the typical learning curve, the rate of 5 years implant failure is in accordance with the registry data for non-cemented implants. The Accolade stem showed minimal radiographic signs of radiolucency.

LEVEL OF EVIDENCE

IV, retrospective, consecutive case series.

The effect of flexion alignment in total hip arthroplasty with a cementless tapered-wedge femoral stem

INTRODUCTION

The influence of stem sagittal alignment on clinical outcomes is unclear in total hip arthroplasty (THA). The purpose of this study is to assess the relationship between stem sagittal alignment and clinical and radiographic outcomes using 3D-CT.

MATERIALS AND METHODS

We performed 370 consecutive primary THAs between 2009 and 2013. After exclusion, 102 hips in 89 patients using single tapered-wedge stem were included. Mean follow-up was 4.7 years. Stem sagittal alignment was measured using CT, and patients were divided into flexion and neutral alignment groups. Clinical and radiographic outcomes were compared between two groups. Furthermore, we evaluated the anterior femoral offset and initial contact state.

RESULTS

There were no significant differences in clinical or radiographic outcomes between two groups. CT data analysis and multiple regression analysis showed flexion alignment increased anterior femoral offset (AFO) and Gruen zone 4 contact area.

CONCLUSIONS

There was no significant difference in clinical or radiographic outcomes between flexion and neutral alignment of the tapered-wedge stem at an average of 4.7 years of follow-up. The increase of AFO and distal contact area in flexion alignment could affect the improvement of impingement-free range of flexion and intraoperative fracture.

A Prospective Randomized Trial of Mini-Incision Posterior and 2-Incision Total Hip Arthroplasty: Minimum 5-Year Follow-Up

BACKGROUND

We previously described the results of a randomized controlled trial of mini-posterior vs 2-incision total hip arthroplasty and were unable to demonstrate significant differences in early outcomes. As less-invasive anterior approaches remain popular, the purpose of this report was to re-examine the outcomes at a minimum 5-year follow-up.

METHODS

Seventy-two patients undergoing primary total hip arthroplasty were randomized to a mini-posterior or 2-incision approach. Complications, revisions, and clinical outcome measures were compared. Radiographs were reviewed for implant loosening. A power analysis using a minimal clinically important difference value of 6 points for the Harris hip score revealed 28 patients required per group.

RESULTS

At a mean of 8.2 years (range, 5-10 years), 6 patients died without revision surgery and 63 of 66 living patients were reviewed. There were 6 total failures, 3 in each group. For unrevised patients, there were no significant differences between groups (posterior vs 2-incision) in the Harris hip score (95.5 ± 3.5 vs 95.7 ± 6.3; P = .88), 12-item Short Form Survey physical composite score (50.5 ± 8.5 vs 49.0 ± 9.1; P = .53), 12-item Short Form Survey mental composite score (57.3 ± 4.1 vs 55.4 ± 8.0; P = .25), or single assessment numeric evaluation score (97.1 ± 3.7 vs 97.8 ± 5.2; P = .55).

CONCLUSION

We found no differences in midterm outcomes between the 2 approaches. Given the increased complexity, operative time, and need for fluoroscopy with the 2-incision approach combined with equivalent early and midterm outcomes, the 2-incision approach has been abandoned in the senior author's practice.

Preoperative Planning and Operative Techniques of the Shorter Tapered Stem Compared to the Metaphyseal Fit Stem in Cementless Total Hip Arthroplasty

BACKGROUND

In order to prevent postoperative dislocation due to prosthetic impingement as a result of total hip arthroplasty (THA), the combined anteversion (CA) theory, which combines the anteversion of the femoral stem and the acetabular socket, has been revised in recent years. Particularly, it is necessary to keep CA within the target zone.

METHODS

The aim of this study was to investigate whether postoperative CA can be kept within the target zone while using the operative technique which prepares the socket first in cementless THA, by estimating the anteversion of the metaphyseal fit stem or the shorter, tapered wedge stem using preoperative 3-dimensional computerized planning, and by adjusting the anteversion of the socket using a navigation system that considers CA. One hundred fourteen patients (118 hips) were recruited for the study.

RESULTS

Postoperative CA in THA using the metaphyseal fit stem was kept within the target zone for 56 of the 60 hips (93.3%). Using the shorter, tapered wedge stem, 49 of the 58 hips (84.4%) were within the target zone. No postoperative dislocations were observed in any hips.

CONCLUSION

We found that the metaphyseal fit stem worked better than the shorter, tapered wedge stem in terms of meeting the planned CA. The shorter, tapered wedge stems were flexible in rotation according to the anatomical configuration of the proximal femur. Therefore, the stem could be placed second with the metaphyseal fit stem, but we recommend placing the stem first with the shorter, tapered wedge stem.

Cementless Tapered Wedge Femoral Stems Decrease Subsidence in Obese Patients Compared to Traditional Fit-and-Fill Stems

BACKGROUND

Femoral component stability and resistance to subsidence is critical for osseointegration and clinical success in cementless total hip arthroplasty. The purpose of this study was to radiographically evaluate the anatomic fit and subsidence of 2 different proximally tapered, porous-coated modern cementless femoral component designs.

METHODS

A retrospective cohort study of 126 consecutive cementless total hip arthroplasties was performed. Traditional fit-and-fill stems were implanted in the first 61 hips with the remaining 65 receiving morphometric tapered wedge stems. Preoperative bone morphology was radiographically assessed by the canal flare index. Canal fill in the coronal plane, subsidence, and the sagittal alignment of stems was measured digitally on immediate and 1-month postoperative radiographs.

RESULTS

Demographics and canal flare indices were similar between groups. The percentage of femoral canal fill was greater in the tapered wedge compared to the fit-and-fill stem (P = .001). There was significantly less subsidence in the tapered wedge design (0.3 mm) compared to the fit-and-fill design (1.1 mm) (P = .001). Subsidence significantly increased as body mass index (BMI) increased in the fit-and-fill stems, a finding not observed in the tapered wedge design (P = .013).

CONCLUSION

An anatomically designed morphometric tapered wedge femoral stem demonstrated greater axial stability and decreased subsidence with increasing BMI than a traditional fit-and-fill stem. The resistance to subsidence, irrespective of BMI, is likely due to the inherent axial stability of a tapered wedge design and may be the optimal stem design for obese patients.

Distal femoral cortical hypertrophy after hip arthroplasty using a cementless doubletapered femoral stem

PURPOSE

To review 437 hips in 404 patients who underwent total hip arthroplasty (THA) or hemiarthroplasty using the Accolade TMZF stem to determine the incidence and risk factors of distal femoral cortical hypertrophy (DFCH).

METHODS

Records of 437 hips in 169 men and 235 women aged 26 to 100 (mean, 65.7) years who underwent THA (n=293) or hemiarthroplasty (n=144) using the Accolade TMZF femoral stem by 2 senior surgeons and were followed up for a mean of 54.7 months were reviewed. Clinical outcome was assessed using the modified Harris Hip Score and visual analogue score for pain. Proximal femoral geometry and canal flare index were assessed on preoperative radiographs, and DFCH, stem position, subsidence, loosening, and stress shielding were assessed on postoperative radiographs according to the Gruen zone.

RESULTS

Of 437 hips, 27 (6.2%) developed DFCH and 410 did not. Hips with DFCH had a higher incidence of thigh pain (18.5% vs. 2.2%, p<0.001) and earlier onset of thigh pain (12.3 vs. 20.8 months, p=0.015), compared with those without. Nonetheless, all femoral stems were well-fixed, and no osteolysis or loosening was detected. The 2 groups achieved comparable clinical outcome in terms of Harris Hip Score and pain. The mean canal flare index was higher in hips with than without DFCH (3.706 vs. 3.294, p=0.002). The mean vertical subsidence of the femoral stem was lower in hips with than without DFCH (1.5 vs. 3.4 mmp<0.001). Subsidence negatively correlated with the canal flare index (correlation coefficient= -0.110, p=0.022). The incidence of the DFCH increased with each unit of increment in canal flare index (odds ratio [OR]=1.828, p=0.043) and each year younger in age (OR=0.968, p=0.015).

CONCLUSION

The incidence of DFCH in hips withthe Accolade TMZF stem was 6.2%. Patients with a higher canal flare index and younger age had a higher incidence of DFCH. Nonetheless, DFCH did not affect clinical outcome or femoral stem stability.

Does the Canal Fill Ratio and Femoral Morphology of Asian Females Influence Early Radiographic Outcomes of Total Hip Arthroplasty With an Uncemented Proximally Coated, Tapered-Wedge Stem?

BACKGROUND

Noncement femoral fixation in total hip arthroplasty (THA) has been gaining popularity. However, owing to the numerous varieties of uncemented stems and differing types of femoral stem morphology, it is unclear whether the clinical outcomes of all uncemented stems are equal. The aim of this study was to investigate the relationships between canal fill ratio and femoral morphology and early radiologic outcomes in Japanese patients who underwent THA with an uncemented proximally hydroxyapatite-coated, tapered-wedge stem.

METHODS

We retrospectively reviewed 103 patients who had undergone THA using a single proximally coated tapered-wedge stem. The relationships between canal fill ratio and femoral morphology and early radiologic outcomes after THA with those stem were investigated.

RESULTS

Eighty-one hips were analyzed after inclusion and exclusion criteria were applied. Failed osteointegration proximally was observed in 4 hips (4.9%). Canal flare index was significantly greater in hips with failed osteointegration than in those with successful osteointegration (P = .009). Distal hypertrophy was observed in 14 hips (17.3%). Proximal-distal matching ratio was significantly lower in hips with distal hypertrophy than in those without (P = .01). Canal fill ratio at 2 cm above the lesser trochanter was smaller in hips with failed osteointegration and distal hypertrophy than in those without (P = .02).

CONCLUSION

Suboptimal radiologic changes were seen with greater distal fill with smaller proximal fill and with a narrow femoral canal. It is important to select the stem that can achieve the original concept of intended primary and secondary fixation areas.

WOMAC and SF-36: instruments for evaluating the health-related quality of life of elderly people with total hip arthroplasty. A descriptive study

CONTEXT AND OBJECTIVES

Quality-of-life results have increasingly been evaluated among patients undergoing joint replacements. The objective of this study was to compare two assessment instruments for health-related quality of life (one generic and the other specific), among elderly patients undergoing total hip arthroplasty.

DESIGN AND SETTING

Cross-sectional descriptive study in a reference hospital in the region of Campinas.

METHODS

The subjects were 88 elderly outpatients aged 60 years or over who underwent primary total hip arthroplasty. Two instruments for assessing health-related quality of life were applied: the generic Medical Study 36-item Short-Form Health Survey (SF-36) and the specific Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Cronbach's alpha and the ceiling and floor effects of the instruments were evaluated.

RESULTS

The scores from both instruments showed that issues of a physical nature affected these elderly people's quality of life most. The pain and stiffness dimensions of WOMAC showed ceiling effects and only the functional capacity and pain dimensions of the SF-36 did not show the ceiling effect. The SF-36 presented floor effects in the dimensions of physical and emotional aspects. Cronbach's alpha was considered satisfactory in both instruments (α > 0.70).

CONCLUSIONS

The floor and ceiling effects that were observed suggest that these instruments may present some limitations in detecting changes to the majority of the SF-36 dimensions, except for functional capacity and pain, and to the pain and stiffness dimensions of WOMAC, when applied to elderly people with total hip arthroplasty.

Radiographic fit and fill analysis of a new second-generation proximally coated cementless stem compared to its predicate design

The purpose of this study was to compare in vivo fit and fill analysis of a new second-generation proximally coated cementless stem compared to its predicate design. This prospective trial of 100 total hip arthroplasties compared specific radiographic "Fit and Fill" parameters between the two designs. Fit type was assessed by comparing the type of canal fill. Post-operative fill parameters such as mean stem-to-canal ratios and mean minimum and maximum gaps between the stems to the cortical bone in different sections and areas were compared. A significantly higher proportion of the second-generation stems had Type I fit (82% vs. 54%), had better stem to canal fill ratio in the middle (90.6% vs. 85.3%) and distal sections (88.1% vs. 78.6%) compared to the older design. The new second-generation stem design had a significantly better canal fit and distal canal fill in the medial and lateral portions.

Results of a tapered proximally-coated primary cementless stem for revision hip surgery

Nineteen patients (nineteen hips) who had undergone revision total hip arthroplasties using a proximally-coated primary cementless stem were evaluated to determine if a subset of revision arthroplasty patients could be identified where the use of this stem would be appropriate. Of these 19 revisions, 15 were performed for the second stage treatment of infection. The femoral bone deficiency was classified as Paprosky Type I in 6 hips and Type II in 13 hips. At a mean follow-up of 49 months, aseptic stem survivorship was 95% with one revision due to aseptic stem failure. The mean Harris hip scores had improved from a mean of 44 points pre-operatively to 89 points post-operatively. Intra-operatively, there was one complication which included a peri-prosthetic fracture distal to the stem which was treated with an allograft strut with cerclage wires. The authors believe that in type I or II femoral defects, the use of this specific cementless stem may be beneficial in the setting of a revision total hip arthroplasty.

Four- to six-year follow-up of primary THA using contemporary titanium tapered stems

Tapered cementless femoral components have been used in total hip arthroplasty constructs for more than 20 years. In the past 5 to 10 years, these stems have gained popularity in the United States. The purpose of this study was to evaluate the results of the authors’ initial experience using a contemporary tapered, proximally porous-coated, titanium femoral component at 4 to 6 years of follow-up. Eighty-eight patients underwent 100 total hip arthroplasties using the Summit stem (DePuy, Warsaw, Indiana) and a cementless acetabular component. Average age at the time of surgery was 61.6 years. Patients were prospectively followed for 4 to 6 years or until death. Patients were evaluated clinically using Harris Hip Scores and the need for revision. Radiographs were evaluated for femoral loosening and osteolysis. At final follow-up, no hips had been revised for femoral or acetabular loosening. Two hips required revision for dislocation and 1 for early femoral fracture. Bony ingrowth was seen in all but 2 femoral components. There was 1 instance of proximal femoral osteolysis and none distally on radiographs (cross-linked polyethylene was used in 73% of cases). There were 2 cases of severe stress shielding. One percent of cases had an early fracture (too tight) and 1% subsided without ingrowth (too loose). One patient reported significant thigh pain that did not limit activity. At final follow-up, the Summit femoral component demonstrated durable results at 4 to 6 years. Stability of the implant without femoral fracture is paramount.

Minimum 5-year follow-up for primary THA using a tapered, proximally coated cementless stem

The purpose of this study was to assess the survivorship of a proximally coated, cementless femoral stem used for total hip arthroplasty at a minimum 5-year follow-up by assessing clinical outcomes and implant survival. A total of 936 primary total hip arthroplasties were performed in 854 patients by 3 high-volume surgeons between 2001 and 2007. Patients included 385 men and 469 women with a mean age of 56 years (range, 20-88 years) and a mean follow-up of 7 years (range, 5-11 years). The aseptic revision rate related to the femoral component was 0.3%. Three patients underwent revision of the femoral component. Mean postoperative Harris Hip Score improved to 91 points (range, 70-100 points). When stratified by primary cause of total hip arthroplasty, no differences were found in implant survivorship or postoperative Harris Hip Scores. With the exception of the 3 patients who underwent revision surgery, postoperative radiographic evaluation of the stems demonstrated no progressive radiolucencies, component malalignment, change in component position, or implant subsidence at most recent follow-up.These results are encouraging and indicate a 0.3% revision rate for the femoral component. The cause of primary total hip arthroplasty did not affect the clinical outcomes. These types of prostheses will provide patients with a stable implant that is expected to have excellent durability and longevity.

Bipolar hemiarthroplasty for femoral neck fracture using the direct anterior approach

AIM: To evaluate whether walking ability recovers early after bipolar hemiarthroplasty (BHA) using a direct anterior approach.

METHODS: Between 2008 and 2010, 81 patients with femoral neck fracture underwent BHA using the direct anterior approach (DAA) or the posterior approach (PA). The mean observation period was 36 mo. The age, sex, body mass index (BMI), time from admission to surgery, length of hospitalization, outcome after discharge, walking ability, duration of surgery, blood loss and complications were compared.

RESULTS: There was no significant difference in the age, sex, BMI, time from admission to surgery, length of hospitalization, outcome after discharge, duration of surgery and blood loss between the two groups. Two weeks after the operation, assistance was not necessary for walking in the hospital in 65.0% of the patients in the DAA group and in 33.3% in the PA group (P < 0.05). As for complications, fracture of the femoral greater trochanter developed in 1 patient in the DAA group and calcar crack and dislocation in 1 patient each in the PA group.

CONCLUSION: DAA is an approach more useful for BHA for femoral neck fracture in elderly patients than total hip arthroplasty in terms of the early acquisition of walking ability.

Total hip arthroplasty at the rothman institute

BACKGROUND

Total hip arthroplasty (THA) is one of the most successful surgical interventions devised in modern times. Attempts to change the current THA procedure with unproven innovations bring the risk of increased failure rates while trying to improve the benefit of the surgery.

QUESTIONS/PURPOSES

This manuscript examines the evolution of THA at the Rothman Institute illustrating the key elements that lead the success of this procedure at this institution. These key elements include femoral stem design, use of highly crossed-linked polyethylene and use of pain and rehabilitation protocols. We attempted to describe the long-term results regarding safety, effectiveness, and durability of specific THA implant designs used at this institution drawing on reported evidence in the literature.

METHODS

The authors performed a review of peer-reviewed articles related to the Rothman Institute's experience with THA.

RESULTS

Total hip arthroplasty is an efficient, safe, and durable procedure. It is a highly successful operation to restore function and improve pain. The survivorship of THA procedures at the Rothman Institute is higher than 99% at 10 years based on mechanical failure. The use of collarless, tapered wedge femoral stem, highly crossed-linked polyethylene, and improved pain rehabilitation protocols have contributed to this success.

CONCLUSIONS

There is a well-documented long-term survivorship after THA. Future innovation in THA should address new challenges with younger and more demanding patients, rather than change current methods that have a proven good survivorship. This innovation depends mainly upon improvements in the bearing surfaces and advances in pain control and rehabilitation.

Use of cementless, tapered femoral stems in patients who have a mean age of 20 years

Young patients who undergo total hip arthroplasty are a unique group who has been challenging to successfully treat; however, newer prosthetic materials and designs have the potential to increase implant longevity. Fifty-three hips (40 patients who had a mean age of 20 years) underwent a total hip arthroplasty using a cementless, proximally hydroxyapatite-coated, tapered, femoral stem and a cementless acetabular cup. There was a 96% overall survivorship at approximately 5 years of mean follow-up (range, 2-7 years) with no femoral side failures. Younger patients undergoing total hip arthroplasty with newer component designs and materials may have similar excellent outcomes to older patients.

High incidence of migration with poor initial fixation of the Accolade stem

BACKGROUND

Numerous cementless femoral stem design variations are in clinical use. Because initial implant instability and micromotion are associated with aseptic loosening of the femoral component, migration analysis provides an early assessment of implant survivorship.

QUESTIONS/PURPOSES

We determined the (1) migration pattern of the Accolade cementless femoral stem; (2) clinical factors predisposing to stem migration; (3) self-reported patient outcomes; and (4) our current rate of aseptic stem loosening.

METHODS

We retrospectively analyzed 81 femoral stems for aseptic migration using Ein-Bild-Roentgen-Analyse-femoral component analysis. Postoperatively, patients completed the WOMAC and SF-12 questionnaires. We assessed radiographic factors potentially associated with subsidence: indices of bone shape and quality, canal fill of the implant, and radiographic signs of loosening. Minimum followup was 24 months (mean, 29 months; range, 24-48 months).

RESULTS

The average subsidence at 24 months was 1.3 mm (range, 0-1.5 mm). In the first 2 years, 36% of stems subsided more than 1.5 mm. Large stem size was associated with subsidence. Radiolucent lines (> 1.5 mm in three zones) were present in 10% of stems and associated with lower questionnaire scores. The 5-year survivorship for aseptic loosening of the 367 stems was 97% with revision as end point and 95% for radiographic failure.

CONCLUSIONS

The high incidence of migration and stems with radiographic failure raises concerns about patient clinical function and long-term survivorship of this stem design. This migration pattern may be due to poor initial stability with a subsequent lack of osseointegration. Our results differ from radiographic findings and clinical durability of other similar cementless stem designs.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Primary total hip arthroplasty with an uncemented femoral component five- to nine-year results

This study reports the outcome of total hip arthroplasty with use of an uncemented, tapered stem with a 5- to 9-year follow-up. The first 200 consecutive patients (214 hips) undergoing total hip arthroplasty with the Accolade TMZF stem (Stryker Orthopaedics, Mahwah, NJ) were enrolled prospectively. Follow-up for these patients averaged 7.6 years and encompassed review of clinical records as well as review of serial anteroposterior and lateral radiographs. There were 5 revision surgeries for aseptic loosening, 2 cases of infection, instability, and polyethylene wear. Our failure rate, defined as hips needing revision, was 2.6%, and the failure rate due to aseptic loosening of the femoral component was 0.6%. These results demonstrate the high success rate of this implant providing support for its continued use.

The Bicontact cementless primary total hip arthroplasty: long-term results

We report on a prospective series of 201 primary uncemented total hip arthroplasties with a Bicontact prosthesis at a mean follow-up of 12.9 years. The mean Harris hip score improved from 41 before surgery to 89 at final follow-up. Two femoral stems, one each for infection and fracture, and 12 cups were revised. The mean number of years to revision post-primary surgery was 8.7 years (six months to 16 years). The cumulative survival of the prosthesis was 95.42% for any cause at ten years and 93.57% at 12 years. Survivorship for aseptic loosening of the femoral stem was 100%. In our series, the Bicontact uncemented total hip arthroplasty stem without hydroxyapatite coating showed excellent survival and the cup survival was comparable to other leading series.

Hip resurfacing arthroplasty for ankylosing spondylitis

We compared the results of the metal-on-metal hip resurfacing with the ceramic-on-ceramic total hip arthroplasty (THA) in 2 groups. The preoperative and postoperative ranges of motion (ROMs) were recorded. At the latest follow-up, both of the groups make satisfactory clinical and radiographic results. There was no significant difference in Harris hip score of the 2 groups, but the ROM of the hips in hip resurfacing group was significantly wider than THA group (P < .01). Hip resurfacing has better ROM improvement than THA, with the same pain relief. Its high stability and low dislocation rate allow patients to do early function exercises, which is important for ankylosing spondylitis (AS) patients to avoid reankylosis. Hip resurfacing may be a reasonable option for young AS population.

Mid-term results of the modular ANCA-Fit femoral component in total hip replacement

We report the minimum five-year follow-up of 352 primary total hip replacements using the uncemented hydroxyapatite-coated ANCA-Fit femoral component with a modular neck and head. The series comprised 319 patients (212 men, 107 women) with a mean age at operation of 64.4 years (28 to 97). The principal diagnosis was osteoarthritis. A total of 18 patients (21 hips) died before their follow-up at five years, nine patients (11 hips) were lost to follow-up, and four (four hips) declined further follow-up. Patient-reported outcomes have been recorded for 288 patients (316 hips).

Their mean Oxford Hip Score improved significantly from 41 points (16 to 57) pre-operatively to 20 points (12 to 44) at five-year follow-up. Radiological assessment showed good bony stability in 98% of implants. There were two cases of aseptic loosening of the femoral component. There were no clinical or radiological complications related to modularity. In our series we did not see the high rate of intra-operative fracture previously reported for this implant.

This medium-term follow-up study demonstrates that the clinical outcome of the ANCA-Fit femoral component is, to date, comparable with that of other metaphyseal loading femoral components.