Association between fixation technique and revision risk in total hip arthroplasty patients younger than 55 years of age. Results from the Nordic Arthroplasty Register Association

The 'Japanese paradox' of total hip arthroplasty: where are we going?

INTRODUCTION

There is a worldwide trend toward 'revisiting' cemented total hip arthroplasty (THA). In Japan, however, cemented THAs accounts for 11%, and the percentage of cemented hemiarthroplasty is estimated to be less than 10%. This review was designed to reconsider the option of cemented THA and to encourage policy changes in Japan to support the best possible care for patients.

AREA COVERED

In this article, we reviewed the history of THA and the current situations of the world, based on past reports and nationwide registries. Merits and demerits of cemented THA were evaluated from various perspectives.

EXPERT OPINION

Cemented THA had great advantages, including establishment of the acetabular cup, diversity of the femoral stem, antibiotic-loaded acrylic cement, revision, low incidence of periprosthetic fracture, and hemiarthroplasty. In patients older than 75 years of age, cemented THA resulted in the lowest risk of revision. Guidelines for femoral neck fracture recommended the use of cemented hemiarthroplasty in many countries because of low incidence of periprosthetic fracture. Numerous contradictions regarding implant price and cost of operations have also been noted in Japan. For the patients, we need to rethink what is truth and what is fiction.

Association of osteotomy, age, and component fixation with the outcomes of total hip arthroplasty in patients with hip dysplasia: a Dutch population-based registry study

BACKGROUND AND PURPOSE

 Hip dysplasia can present challenges for total hip arthroplasty (THA) due to anatomic abnormalities. We aimed to assess the association of age, sex, osteotomies prior to THA, and fixation method on 5- and 10-year revision-free implant survival and patient-reported outcome measures (PROMs) of THAs in patients with hip dysplasia.

METHODS

Using Dutch Arthroplasty Register data, we studied hip dysplasia patients receiving primary THAs in 2007-2021 (n = 7,465). THAs were categorized by age, pelvic osteotomy prior to THA (yes/no), and fixation (cemented, uncemented, hybrid, reverse hybrid). Kaplan-Meier and multivariable Cox models were used to determine 5- and 10-year revision-free implant survival and adjusted hazard ratios including 95% confidence intervals (CIs). Reasons for revision and PROMs were compared within the categories.

RESULTS

 We found a 10-year revision-free implant survival of 94.9% (CI 94.3-95.5). Patients younger than 50 years had a 10-year implant survival of 93.3% (CI 91.9-94.7), Patients with prior pelvic osteotomy had a 10-year implant survival of 92.0% (CI 89.8-94.2). Fixation method and sex were not associated with implant survival. Patients with a prior pelvic osteotomy had more revisions due to cup loosening and reported lower PROM scores than patients without earlier osteotomy.

CONCLUSION

 5- and 10-year revision-free implant survival rates of THA for hip dysplasia are 96.4% and 94.9%. Age and prior osteotomies were associated with decreased implant survival rates in patients with hip dysplasia, while fixation method was not. Prior osteotomies were also associated with reduced PROM scores.

Increasing femoral head size from 32 mm to 36 mm does not increase the revision risk for total hip replacement: a New Zealand joint registry study

BACKGROUND

The use of larger femoral heads in total hip replacement (THR) has increased over the last decade. While the relationship between increasing head size and increased stability is well known, the risk of revision with increasing head size remains poorly understood. The aim of this study was to compare the outcome of total hip joint replacement with 32-mm and 36-mm heads.

METHODS

We carried out a 20-year retrospective analysis of prospective data from the New Zealand Joint Registry (NZJR). All primary total hip replacements registered between January 1999 and December 2018 were included. We compared the rate of revision of 32-mm and 36-mm heads in THR. Sub-group analysis included comparisons of bearing type and all-cause revision.

RESULTS

60,051 primary THRs met our inclusion criteria. The revision rate per 100 component years was significantly higher with a 36-mm head than with a 32-mm head (0.649 vs. 0.534, p < 0.001). Subgroup analysis of bearing type showed no significant differences in revision rates for all combinations of 36-mm heads when compared to 32-mm (p = 0.074-0.92), with the exception of metal-on-metal (MoM); p = 0.038. When MoM was removed there was no significant difference in revision rates per 100 component years between 32-mm and 36-mm heads, 0.528 versus 0.578 (p = 0.099).

CONCLUSIONS

Increasing head size from 32 mm to 36 mm results in no significant increase in revision in all bearing combinations except MoM.

A Scoping Review of Total Hip Arthroplasty Survival and Reoperation Rates in Patients of 55 Years or Younger: Health Services Implications for Revision Surgeries

Background

Total hip arthroplasty (THA) in younger patients is projected to increase by a factor of 5 by 2030 and will have important implications for clinical practice, policymaking, and research. This scoping review aimed to synthesize and summarize THA implants' survival, reoperation, and wear rates and identify indications and risk factors for reoperation following THA in patients ≤55 years old.

Material and methods

Standardized scoping review methodology was applied. We searched 4 electronic databases (Medline, Embase, CINAHL, and Web of Science) from January 1990 to May 2019. Selection criteria were patients aged ≤55 years, THA survival, reoperation, and/or wear rate reported, a minimum of 20 reoperations included, and minimum level III based on the Oxford Level of Evidence. Two authors independently reviewed the citations, extracted data, and assessed quality.

Results

Of the 2255 citations screened, 35 retrospective cohort studies were included. Survival rates for THA at 5 and 20 years were 90%-100% and 60.4%-77.7%, respectively. Reoperation rates at ≤5-year post THA ranged from 1.6% to 5.4% and increased at 10-20 years post THA (8.2%-67%). Common causes for reoperation were aseptic loosening of hip implants, osteolysis, wear, and infection. Higher reoperation and lower survival rates were seen with hip dysplasia and avascular necrosis than with other primary diagnoses.

Conclusions

Over time, THA prosthetic survival rates decreased, and reoperation increased in patients ≤55 years. Aseptic loosening of hip implants, osteolysis, wear, and infection were the most frequent reasons for the reoperation.

Revision Risk in a Cohort of US Patients Younger Than 55 Undergoing Primary Elective Total Hip Arthroplasty

BACKGROUND

As indications for elective total hip arthroplasty (THA) expand to younger patients, we sought to (1) compare revision risk following primary elective THA in patients <55 years at the time of their THA to patients aged ≥65 years and (2) identify specific risk factors for revision in patients <55 years.

METHODS

A Kaiser Permanente's total joint replacement registry was used to conduct a cohort study including primary elective THA patients aged ≥18 (2001-2018). In total, 11,671 patients <55 years and 53,106 patients ≥65 years were included. Multiple Cox regression was used to evaluate cause-specific revision risk, including septic revision, aseptic loosening, instability, and periprosthetic fracture. Stepwise Cox regression was used to identify patient and surgical factors associated with cause-specific revision in patients <55 years.

RESULTS

Patients <55 years had a higher risk of septic revision (hazard ratio [HR] = 1.30, 95% confidence interval [CI] = 1.02-1.66), aseptic loosening (HR = 2.60, 95% CI = 1.99-3.40), and instability (HR = 1.35, 95% CI = 1.09-1.68), but a lower risk of revision for periprosthetic fracture (HR = 0.36, 95% CI = 0.22-0.59) compared to patients aged ≥65 years. In the <55 age group, risk factors for septic revision included higher body mass index, drug abuse, and liver disease. Hypertension, anterior approach, and ceramic-on-ceramic were associated with aseptic loosening. White race, American Society of Anesthesiologists classification ≥3, smoker, paralysis, posterior approach, ceramic-on-ceramic, and smaller head diameter were associated with instability.

CONCLUSION

Identified risk factors varied depending on the cause for revision. Although septic revisions were related to patient characteristics, more modifiable factors, such as implant or surgical approach, were associated with revision due to aseptic loosening and instability.

LEVEL OF EVIDENCE

III.

Cemented Polished Tapered Stems Have Lower Revision Rates Than Commonly Used Cementless Implant up to 17 Years of Follow-Up: An Analysis of 201,889 Total Hip Replacements From the Australian Orthopedic Association National Joint Replacement Registry

BACKGROUND

Data assessing femoral stems may be influenced by grouping together matt and polished stems, despite their differing reported survivorship. The aim of this study is to assess the difference in revision rates between commonly used cemented and cementless stems when polished tapered stems are assessed independently of matt stems.

METHODS

Australian Orthopaedic Association National Joint Replacement Registry data from 1999 to 2019 were used to assess difference in revision rates between the 5 most commonly implanted femoral cemented and cementless stems for osteoarthritis. Cemented matt femoral stems, stems using line-to-line cementing techniques and procedures using non-cross-linked polyethylene, large head (>32 mm) metal-on-metal bearing surfaces or exchangeable necks were excluded. Cumulative percent revision was used to help compare survivorship between stems.

RESULTS

There were 201,889 total hip replacements meeting the inclusion criteria, of which 50.0% were cemented and 50.0% cementless. Cemented stems had a lower rate of revision at all time points compared to cementless stems. This was most significant during the first 2 weeks (hazard ratio 0.48, 95% confidence interval 0.40-0.58, P < .001) compared to 2 weeks postoperatively and onwards (hazard ratio 0.85, 95% confidence interval 0.81-0.90, P < .001). A subanalysis of head size, bearing type, and surgeon volume further supported the use of a cemented stem.

CONCLUSION

Commonly used cemented polished tapered stems have a lower revision rate when compared to commonly used cementless prostheses, and are recommended in all age groups for both low-volume and high-volume surgeons especially when head size 32 mm or smaller is used.

A Comparison of Risks and Benefits Regarding Hip Arthroplasty Fixation

Since the field-changing invention of noncemented hip arthroplasty fixation in the 1980s, noncemented fixation has been progressively replacing cemented fixation. However, analyses of fixation frequencies reveal new patterns in cement versus noncemented preferences. Although cementation is again gaining ground in the United States, noncemented models remain the dominant fixation mode, seen in more than 90% of all hip arthroplasties. This stark preference is likely driven by concerns regarding implant durability and patient safety. Although advances in surgical techniques, intensive perioperative care, and improved instrument have evolved in both methods, data from large arthroplasty registries reveal shifting risks in contemporary hip arthroplasty, calling the use of noncemented fixation into question. Varying risk profiles regarding sex, age, or health comorbidities and morphological and functional differences necessitate personalized risk assessments. Furthermore, certain patient populations, based on the literature and data from large registries, have superior outcomes from cemented hip arthroplasty techniques. Therefore, we wanted to critically evaluate the method of arthroplasty fixation in primary hip arthroplasties for unique patient populations.

Review of total hip arthroplasty in patients younger than 30 years: mid- to long-term results

BACKGROUND

Data on the outcome of THA in patients under the age of 30 years is sparse. There is a perceived reluctance to offer surgery to young patients on the basis of potential early failure of the implant. The aim of this study was to review clinical and radiological outcomes of THA in patients under the age of 30 years in a high-volume specialist arthroplasty unit.

METHODS

A retrospective review of patients between 1989 and 2009 was undertaken. 95 patients (118 THAs) were identified but 17 patients were excluded for lack of clinical records or for follow-up under 5 years. Clinical records were reviewed for demographics, underlying pathology, details of operation and failures. Radiographs were reviewed for evidence of loosening and wear of the components. Functional assessment was carried out using the modified Hip disability and Osteoarthritis Outcome Score, Oxford Hip Score and EQ-5D-5L.

RESULTS

Mean age was 25 (16-30) years and 65% patients were females. The most common underlying pathologies were development dysplasia of the hip (29%) and juvenile rheumatoid arthritis (25%). Mean follow-up was 12.6 (5-24) years, during which 19 patients (25%) were revised. The majority of the revisions were for aseptic loosening of the acetabular component.

CONCLUSIONS

Surgeons are cautious when considering THA in very young patients despite the significant documented improvement in function and quality of life after THA. This study reports on the mid- to long-term results of THA which will be valuable when advising young patients on the prospects of revision surgery at the time of primary THA.

Long-term survival after cemented versus uncemented total hip arthroplasty for treatment of acute femoral neck fracture: a retrospective study with a mean 10-year follow-up

Objective

To compare the long-term survivorship and Harris hip scores (HHSs) between cemented total hip arthroplasty (CTHA) and uncemented total hip arthroplasty (UTHA) for treatment of acute femoral neck fractures (FNFs).

Methods

Data of 224 hips (CTHA, n = 112; UTHA, n = 112) that underwent primary surgery in our medical institution from 2005 to 2017 were retrospectively analysed. The primary endpoint was the risk of all-cause revision. The difference in the risk of all-cause revision between the two groups was assessed by Kaplan–Meier survival analysis with a log-rank test and Cox regression analysis.

Results

The mean postoperative follow-up was 10 years (range, 3–13 years). The Kaplan–Meier estimated 10-year implant survival rate was significantly higher in the CTHA than UTHA group (98.1% vs. 96.2%, respectively). The adjusted Cox regression analysis demonstrated a significantly lower risk of revision in the CTHA than UTHA group. At the final follow-up, the mean HHS was significantly higher in the CTHA than UTHA group (85.10 vs. 79.11, respectively).

Conclusion

This retrospective analysis demonstrated that CTHA provided higher survival, lower revision risk, and higher functional outcome scores than UTHA. Further follow-up is necessary to verify whether these advantages of CTHA persist over time.

Risk factors for a radiolucent line around the acetabular component with an interface bioactive bone cement technique after primary cemented total hip arthroplasty

Aims

The main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA.

Methods

A retrospective review was undertaken of 980 primary cemented THAs in 876 patients using cemented acetabular components with the IBBC technique. The outcome variable was any RLLs that could be observed around the acetabular component at the first year after THA. Univariate analyses with univariate logistic regression and multivariate analyses with exact logistic regression were performed to identify risk factors for any RLLs based on radiological classification of hip osteoarthritis.

Results

RLLs were detected in 27.2% of patients one year postoperatively. In multivariate regression analysis controlling for confounders, atrophic osteoarthritis (odds ratio (OR) 2.17 (95% confidence interval (CI), 1.04 to 4.49); p = 0.038) and 26 mm (OR 3.23 (95% CI 1.85 to 5.66); p < 0.001) or 28 mm head diameter (OR 3.64 (95% CI 2.07 to 6.41); p < 0.001) had a significantly greater risk for any RLLs one year after surgery. Structural bone graft (OR 0.19 (95% CI 0.13 to 0.29) p < 0.001) and location of the hip centre within the true acetabular region (OR 0.15 (95% CI 0.09 to 0.24); p < 0.001) were significantly less prognostic. Improvement of the cement-bone interface including complete disappearance and poorly defined RLLs was identified in 15.1% of patients. Kaplan-Meier survival analysis for the acetabular component at ten years with revision of the acetabular component for aseptic loosening as the end point was 100.0% with a RLL and 99.1% without a RLL (95% CI 97.9 to 100). With revision of the acetabular component for any reason as the end point, the survival rate was 99.2% with a RLL (95% CI 97.6 to 100) and 96.5% without a RLL (95% CI 93.4 to 99.7).

Conclusion

This study demonstrates that acetabular bone quality, head diameter, structural bone graft, and hip centre position may influence the presence of the any RLL.

Cite this article: Bone Joint Open 2021;2(5):278–292.

Uncemented or cemented stems in first-time revision total hip replacement? An observational study of 867 patients including assessment of femoral bone defect size

Background and purpose - Uncemented stems are gradually replacing cemented stems in hip revision surgery. We compared the risk of re-revision between uncemented and cemented revision stems and assessed whether the different fixation methods are used in similar femoral bone defects.Patients and methods - 867 patients operated on with uncemented or cemented stems in first-time hip revision surgery due to aseptic loosening performed 2006-2016 were identified in the Swedish Hip Arthroplasty Register. Preoperative femoral bone defect size was assessed on radiographs of all patients. Cox regression models were fitted to estimate the adjusted risk of re-revision during different postoperative time periods. Re-revision of any component for any reason, and stem re-revision, as well as risk of cause-specific re-revision was estimated.Results - Most patients in both fixation groups had Paprosky class IIIA femoral bone defects prior to surgery, but there were more severe bone defects in the cemented group. The adjusted risk of re-revision of any component for any reason was higher in patients with uncemented compared with those with cemented revision stems during the first 3 years after index surgery (hazard ratio [HR] 4, 95% confidence interval [CI] 2-9). From the 4th year onward, the risk of re-revision of any component for any reason was similar (HR 0.5, CI 0.2-1.4). Uncemented revision stems conferred a higher risk of dislocation compared with cemented stems (HR 5, CI 1.2-23) during the first 3 years.Interpretation - Although not predominantly used in more complex femoral defects, uncemented revision stem fixation confers a slightly higher risk of re-revision during the first years, but this risk is attenuated after longer follow-up.

Minimum 5 year follow-up of clinical and radiographic results of cemented acetabular components with an interface bioactive bone cement technique in primary cemented total hip arthroplasty

INTRODUCTION

A well-fixed cement-bone interface is a crucial factor for acetabular and femoral components in cemented total hip arthroplasty (THA). The aim of the present study was to evaluate the middle-term clinical and radiological results of fixing the acetabular component with an interface bioactive bone cement (IBBC) technique in primary cemented THA.

MATERIALS AND METHODS

We undertook a retrospective review was undertaken of 193 primary cemented THAs in 174 patients using acetabular components cemented with an IBBC technique and followed for a minimum of 5 years (mean 8.3 years; range 5-17 years). Baseline data, clinical and radiological outcomes were evaluated.

RESULTS

Japanese Orthopedic Association hip score and modified Harris hip scores demonstrated significant clinical improvement in all patients (p < 0.001). Radiolucent lines were detected in 15 hips (7.8%) at the first year and 24 hips (12.4%) at the final post-operative follow-up. The Kaplan-Meier survivorship with radiographic loosening as the end point was 97.8% [95% confidence interval (CI) 95.2-100]. With revision of the acetabular component for aseptic loosening as the end point, component survival was 99.0% (95% CI 97.5-100). With revision of the acetabular component for any reason as the end point, component survival was 97.0% (95% CI 93.9-100).

CONCLUSIONS

Clinical and radiological results of the acetabular component with the IBBC technique in primary cemented THA were excellent.

What Is the Long-term (27- to 32-year) Survivorship of an Uncemented Tapered Titanium Femoral Component and Survival in Patients Younger Than 50 Years?

BACKGROUND

Uncemented femoral components in primary THA are in widespread use, especially in patients younger than 50 years, but few studies have evaluated their survival into the late third and early fourth decade.

QUESTIONS/PURPOSES

We evaluated (1) survivorship using femoral revision for any reason as the endpoint, (2) survivorship using femoral revision for aseptic loosening as the endpoint, (3) survival in patients younger than 50 years, (4) cumulative incidence of stem revision for periprosthetic femoral fracture and (5) the overall risk of revision (change of any part of the implanted components) at a minimum of 27 years of follow-up with an uncemented tapered titanium stem still in clinical use today.

METHODS

We reviewed the clinical and radiographic results of 326 THAs performed in 326 patients (for 28 patients with bilateral THA, only the first hip was included in the analysis to ensure independent observations) using an uncemented grit-blasted, tapered collarless titanium alloy (TiAl6Nb7) stem between January 1985 and December 1989. In that same timeframe, we performed 1038 primary THAs. During that time, we used cementless stems in patients without severe femoral canal deformity and adequate bone stock for uncemented femoral fixation as determined by using the indication criteria described by the developer. In all, 34% (354 of 1038) were cementless; all cementless stems implanted during that time were the stem being studied here. No others were used. The mean (range) age at the time of surgery was 56 years (13-81 years). Sixty-seven patients were younger than 50 years at the time of primary THA. A competing risk survivorship analysis was used to estimate long-term survival. The minimum follow-up was 27 years (mean 28 years; range 27-32 years); at that time, 169 patients had died, and four patients were lost to follow-up.

RESULTS

Survivorship at 28 years with revision of the femoral component for any reason as the endpoint was 87% (95% CI 83 to 90). Survivorship for femoral revision for aseptic loosening as the endpoint was 94% at 28 years (95% CI 90 to 96). Survival in patients younger than 50 years at the time of primary THA was 89% (95% CI 78 to 95) and 95% (95% CI 86 to 98) at 28 years for the endpoints of all stem revisions and aseptic stem loosening, respectively. The overall cumulative incidence of stem revision for periprosthetic femoral fracture was 4% (95% CI 2 to 7) at 28 years. The overall THA survival rate at 28 years with revision for any reason as the endpoint was 57% (95% CI 51 to 62).

CONCLUSIONS

Uncemented femoral fixation of a tapered collarless titanium alloy stem was reliable into the early fourth decade, especially in patients younger than 50 years. Late stem failures in the third and early fourth decade were mainly because of periprosthetic femoral fracture, while aseptic loosening occurred in undersized stems during the early second decade.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Global trends in indications for total elbow arthroplasty: a systematic review of national registries

National registries provide useful information in understanding outcomes of surgeries that have late sequelae, especially for rare operations such as total elbow arthroplasty (TEA).A systematic search was performed and data were compiled from the registries to compare total elbow arthroplasty outcomes and evaluate trends. We included six registries from Australia, the Netherlands, New Zealand, Norway, the United Kingdom and Sweden.Inflammatory arthritis was the most common indication for total elbow arthroplasty, followed by acute fracture and osteoarthritis. When comparing 2000-2009 to 2010-2017 data, total elbow arthroplasty for inflammatory arthritis decreased and total elbow arthroplasty for fracture and osteoarthritis increased. There was an increase in the number of revision TEAs over this time period.The range of indications for total elbow arthroplasty is broadening; total elbow arthroplasty for acute trauma and osteoarthritis is becoming increasingly more common. However, inflammatory arthritis remains the most common indication in recent years. This change is accompanied by an increase in the incidence of revision surgery. Cite this article: EFORT Open Rev 2020;5:215-220. DOI: 10.1302/2058-5241.5.190036.

Hybrid Fixation for Total Hip Arthroplasty Showed Improved Survival Over Cemented and Uncemented Fixation: A Single-Center Survival Analysis of 2156 Hips at 12-18 Years

BACKGROUND

Despite increased use of uncemented and hybrid fixation, there is little evidence of their superiority over cemented implants. The aim of this study is to compare the long-term survivorship of cemented, hybrid and uncemented total hip arthroplasty (THA) at varying ages.

METHODS

A total of 2156 hips (1315 cemented, 324 uncemented, and 517 hybrid) were performed in a single center between 1999 and 2005 with follow-up through to 2017. Registry and local databases were used to determine revision rates and cause. Unadjusted and adjusted competing risk survival analysis was performed.

RESULTS

The cumulative incidence of all-cause revision at 18 years was cemented 10.9%, uncemented 8.9%, and hybrid 6.5%. Cemented fixation had a statistically significant higher risk of all-cause revision than hybrid in the adjusted model for all ages to 65 years (subhazard ratios [SHRs], 2.28-4.67) and a higher risk of revision for loosening, wear, or osteolysis at all ages (SHRs, 3.25-6.07). Uncemented fixation showed no advantage over hybrid fixation at any age, but did show advantages over cemented at younger ages (≤60 years) for all-cause revision (SHRs, 2.3-4.3).

CONCLUSION

Hybrid fixation with conventional polyethylene shows an advantage over cemented hips at all ages. Uncemented THA showed improved survival over cemented only at younger ages and no advantage over hybrid THA.

Fixation, sex, and age: highest risk of revision for uncemented stems in elderly women - data from 66,995 primary total hip arthroplasties in the Norwegian Arthroplasty Register

Background and purpose - There is no consensus on best method of fixation in hip arthroplasty. We investigated different modes of fixation in primary total hip arthroplasty (THA) and the influence of age and sex, to assess need for a differentiated approach.Patients and methods - The study was based on data from the Norwegian Arthroplasty Register in the period 2005-2017. Included were all-cemented, all-uncemented, reverse hybrid (uncemented stem and cemented cup), and hybrid (cemented stem and uncemented cup) THA designs that were commonly used, contemporary and well documented, using different causes of revision as endpoints.Results - From the included 66,995 primary THAs, 2,242 (3.3%) were revised. Compared with all-cemented THAs, all-uncemented had a higher risk of revision due to any cause (RR 1.4; CI 1.2-1.6), mainly due to an increased risk of periprosthetic fracture (RR 5.2; CI 3.2-8.5) and dislocation (RR 2.2; CI 1.5-3.0). Women had considerably higher risk of revision due to periprosthetic fracture after all-uncemented THA (RR 12; CI 6-25), compared with cemented. All-uncemented THAs in women of age 55-75 years (RR 1.3; CI 1.0-1.7) and over 75 years of age (RR 1.8; CI 1.2-2.7), and reverse hybrid THAs in women over the age of 75 (RR 1.5; CI 1.1-1.9) had higher risk of revision compared with cemented. Hybrid THAs (RR 1.0; CI 0.9-1.2) and reverse hybrid THAs (RR 1.0; CI 0.7-1.3) had similar risk of revision due to any cause as cemented THAs.Interpretation - Uncemented stems (all-uncemented and reverse hybrid THAs) had increased risk of revision in women over 55 years of age, mainly due to periprosthetic fracture and dislocation, and should probably not be used in THA in these patients.

To cement or not to cement acetabular cups in total hip arthroplasty: a systematic review and re-evaluation

INTRODUCTION

Total Hip Arthroplasty (THA) in the treatment of primary osteoarthritis of the hip has evolved to a very safe and cost-effective intervention with revision rates below 5% after 10 years. To this day, however, controversy remains on whether or not to cement the acetabular cup.

METHODS

A comprehensive PubMed search of the English literature for studies published between 2007 and 2018 was performed. Studies comparing the clinical (revision rate, functionality), radiological (wear) or economic (cost) differences between cemented (cemented stem with cemented cup) and hybrid (cemented stem with uncemented cup) prostheses for primary osteoarthritis of the hip were identified as eligible.

RESULTS

A total of 1032 studies were identified whereof twelve were included for qualitative synthesis. All studies concerning the risk of revision were based on registry data, covering a total of 365,693 cups. Cemented prostheses had a similar or lower risk of revision compared to hybrid prostheses in every study, but performed slightly worse on functionality and quality of life. While cemented prostheses were the cheapest option, hybrids were the most cost-effective.

DISCUSSION

The widespread preference for cementless fixation of the acetabulum cannot be explained by a superior survival of cementless or hybrid models. Irrespective of age, cemented fixation of the acetabulum remains the gold standard to which other techniques should be compared.

The what, when and how of orthopaedic registers: an introduction into register-based research

Establishment of orthopaedic registers started in 1975 and many registers have been initiated since. The main purpose of registers is to collect information on patients, implants and procedures in order to monitor and improve the outcome of the specific procedure.

Data validity reflects the quality of the registered data and consists of four major aspects: coverage of the register, registration completeness of procedures/patients, registration completeness of variables included in the register and accuracy of registered variables.

Survival analysis is often used in register studies to estimate the incidence of an outcome. The most commonly used survival analysis is the Kaplan–Meier survival curves, which present the proportion of patients who have not experienced the defined event (e.g. death or revision of a prosthesis) in relation to the time. Depending on the research question, competing events can be taken into account by using the cumulative incidence function. Cox regression analysis is used to compare survival data for different groups taking differences between groups into account.

When interpreting the results from observational register-based studies a number of factors including selection bias, information bias, chance and confounding have to be taken into account. In observational register-based studies selection bias is related to, for example, absence of complete follow-up of the patients, whereas information bias is related to, for example, misclassification of exposure (e.g. risk factor of interest) or/and outcome.

The REporting of studies Conducted using Observational Routinely-collected Data guidelines should be used for studies based on routinely-collected health data including orthopaedic registers.

Linkage between orthopaedic registers, other clinical quality databases and administrative health registers may be of value when performing orthopaedic register-based research.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180097

The benefits of collaboration: the Nordic Arthroplasty Register Association

The Nordic Arthroplasty Register Association (NARA) was established in 2007 by arthroplasty register representatives from Sweden, Norway and Denmark with the overall aim to improve the quality of research and thereby enhance the possibility for quality improvement with arthroplasty surgery. Finland joined the NARA collaboration in 2010.

NARA minimal hip, knee and shoulder datasets were created with variables that all countries can deliver. They are dynamic datasets, currently with 25 variables for hip arthroplasty, 20 for knee arthroplasty and 20 for shoulder arthroplasty.

NARA has published statistical guidelines for the analysis of arthroplasty register data. The association is continuously working on the improvement of statistical methods and the application of new ones.

There are 31 published peer-reviewed papers based on the NARA databases and 20 ongoing projects in different phases. Several NARA publications have significantly affected clinical practice. For example, metal-on-metal total hip arthroplasty and resurfacing arthroplasty have been abandoned due to increased revision risk based on i.a. NARA reports. Further, the use of uncemented total hip arthroplasty in elderly patients has decreased significantly, especially in Finland, based on the NARA data.

The NARA collaboration has been successful because the countries were able to agree on a common dataset and variable definitions. The collaboration was also successful because the group was able to initiate a number of research projects and provide answers to clinically relevant questions. A number of specific goals, set up in 2007, have been achieved and new one has emerged in the process.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180058

No Increase in Survival for 36-mm versus 32-mm Femoral Heads in Metal-on-polyethylene THA: A Registry Study

BACKGROUND

During the past decade, the 32-mm head has replaced the 28-mm head as the most common head size used in primary THA in many national registries, and the use of 36-mm heads has also increased. However, it is unclear whether 32-mm and 36-mm heads decrease the revision risk in metal-on-polyethylene (MoP) THA compared with 28-mm heads.

QUESTIONS/PURPOSES

(1) In the setting of the Nordic Arthroplasty Register Association database, does the revision risk for any reason differ among 28-, 32-, and 36-mm head sizes in patients undergoing surgery with MoP THA? (2) Does the revision risk resulting from dislocation decrease with increasing head diameter (28-36 mm) in patients undergoing surgery with MoP THA in the same registry?

METHODS

Data were derived from the Nordic Arthroplasty Register Association database, a collaboration among the national arthroplasty registries of Denmark, Finland, Norway, and Sweden. Patients with primary osteoarthritis who had undergone primary THA with a 28-, 32-, or 36-mm MoP bearing from 2003 to 2014 were included. Patients operated on with dual-mobility cups were excluded. In patients with bilateral THA, only the first operated hip was included. After applying the inclusion criteria, the number of patients and THAs with a complete data set was determined to be 186,231, which accounted for 51% of all hips (366,309) with primary osteoarthritis operated on with THA of any head size and bearing type during the study observation time. Of the included patients, 60% (111,046 of 186,231) were women, the mean age at surgery was 70 (± 10) years, and the median followup was 4.5 years (range, 0-14 years). A total of 101,094 patients had received a 28-mm, 57,853 a 32-mm, and 27,284 a 36-mm head with 32 mm used as the reference group. The revision of any component for any reason was the primary outcome and revision for dislocation was the secondary outcome. Very few patients are estimated to be lost to followup because emigration in the population of interest (older than 65-70 years) is rare. A Kaplan-Meier analysis was used to estimate THA survival for each group, whereas Cox regression models were fitted to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for THA revision comparing the 28- and 36-mm head diameters with the 32-mm head diameters adjusting for age, sex, year of surgery, type of cup and stem fixation, polyethylene type (crosslinked versus conventional), and surgical approach.

RESULTS

In the adjusted Cox regression model, there was no difference in the adjusted risk for revision for any reason between patients with 28-mm (HR, 1.06; 95% CI, 0.97-0.16) and 32-mm heads, whereas the risk of revision was higher for patients with 36-mm heads (HR, 1.14; 95% CI, 1.04-1.26) compared with patients with 32-mm heads. Patients with 28-mm heads had a higher risk of revision for dislocation (HR, 1.67; 95% CI, 1.38-1.98) compared with 32 mm, whereas there was no difference between patients with 36-mm (HR, 0.85; 95% CI, 0.70-1.02) and 32-mm heads.

CONCLUSIONS

After adjusting for relevant confounding variables, we found no benefits for 32-mm heads against 28 mm in terms of overall revision risk. However, when dislocation risk is considered, 32-mm heads would be a better option, because they had a lower risk of revision resulting from dislocation. There were no benefits with the use of 36-mm heads over 32 mm, because the transition from 32 to 36 mm was associated with a higher risk of revision for all reasons, which was not accompanied by a decrease in the risk of revision resulting from dislocation. The use of 32-mm heads appears to offer the best compromise between joint stability and other reasons for revision in MoP THA. Further studies with longer followup, especially of 36-mm heads, as well as better balance of confounders across head sizes and better control of patient-related risk factors for THA revision are needed.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Acetabular Subchondral Bone Decortication and Its Role in the Outcome of Cemented Total Hip Replacement in Young Patients

Purpose

Long-term fixation of cemented acetabular components can be problematic in younger active patients. Our technique is put forward to improve outcomes and maximize implant survivorship in this particular patient population.

Materials and Methods

We report on a cohort of young adult patients (less than 55 years old) with cemented total hip replacement (THR) using a novel technique in preparing and cementing the acetabulum with a minimum follow-up of 10 years (mean follow-up, 14 years). Retrospectively collected data on clinical and radiological outcomes were reviewed.

Results

Sixty-five THRs were performed with the minimum study follow-up period. Average age for patients was 44 years old (range, 19–55 years). The mean Hip Disability and Osteoarthritis Outcome Score for patients at final appointment was 92.7. Radiographs taken at an average of 14 years after operation showed 63 of 65 hips showed no evidence of any radiological loosening. Cup survivorship was 100% at the end of the study period.

Conclusion

Our technique of preparing the acetabulum in combination with cement fixation is reproducible with excellent results in a cohort of patients prone to early aseptic loosening of the acetabular component.

Hip fractures in the non-elderly-Who, why and whither?

Nonelderly hip fracture patients have gathered little scientific attention, and our understanding of the group may be biased by patient case-mix and lack of follow-up. Preconceptions may thwart adequate investigation of bone health and other comorbidities. This literature review focusses on who these patients between 20 and 60 years are, how to treat them and how to evaluate the outcome. 2-11% of the hip fractures occur in non-elderly, equally common in men and women. Every second to forth patient smoke, have chronic diseases, and abuse alcohol. Poor self-rated health, sleep disturbances, low cognitive function and education are associated with increased hip fracture risk in young adults. Bone health is poorly investigated, but literature suggest young patients to have lower bone mineral density regardless of trauma mechanism. Studies contradict on whether surgery within 8-12 h reduce the risk of avascular necrosis in femoral neck fractures (FNF). Based on rationality, surgery ought to be performed promptly, in order to reduce pain and permit rehabilitation. There is no convincing support from the existing literature to use open reduction. Good reduction is mandatory, preferably using a closed reduction technique. The failure rate following internal fixation of displaced FNF in younger patients can be as high as 59%. In some cases a displaced FNF is better treated with a primary arthroplasty; in case of rheumatoid arthritis or osteoarthritis for example. Complications after extracapsular fractures vary from 6 to 23%. The relatively few studies looking at functional outcome in non-elderly use a multitude of outcome measures, precluding comparisons. Many non-elderly patients seem not to fully recover. While some non-elderly hip fracture patients are healthy individuals sustaining high energy trauma, others have low-energy fractures and comorbidities including reduced bone strength (either as a primary or secondary condition). i.e. non-delaying medical optimization, proper surgical technique, bone health investigation and secondary fracture prevention is necessary. Younger hip fracture patients are at risk of permanent loss of function, and negative socioeconomic and psychological consequences. High-energy trauma does not exclude the presence of osteopenia. A hip fracture in adulthood and middle-age is very seldom caused by bad luck only!

A Randomized Seven-Year Study on Performance of the Stemmed Metal M2a-Magnum and Ceramic C2a-Taper, and the Resurfacing ReCap Hip Implants

BACKGROUND

The large-diameter metal-on-metal hip prostheses were expected to have low wear and reduced dislocation rate compared to the traditional metal-on-polyethylene implants. We compare 2 such prostheses, the ReCap resurfacing implant and the M2a-Magnum stemmed implant, with the C2a ceramic-on-ceramic stemmed implant as to clinical performance, serum concentrations of prosthesis metals, and the durability of the implants in a randomized, controlled clinical trial at 7 years of follow-up.

METHODS

All included patients had osteoarthritis. Preoperatively, the size of the implants was estimated from a magnetic resonance imaging (MRI) scan. Follow-up data included serum cobalt and chromium concentrations, Oxford and Harris Hip Scores, leg press and abduction force, 6-minute walk distance, WOMAC and SF-36 self-assessment scores, and from the 7th postoperative year also ultrasonography (US) examination of the soft tissue adjacent to the implant as well as MRI with metal artifact reduction sequence (MARS-MRI) when indicated.

RESULTS

One hundred fifty-two hips in 146 patients were included. The serum cobalt and chromium concentrations were significantly higher for the 2 metal-on-metal prostheses than for the ceramic-on-ceramic, with the M2a-Magnum as the highest. No significant difference was found between the groups concerning physical performance measurements and scores as well as dislocations and prosthesis survival. Five revisions were done and concerned all groups, for reasons of pain, high serum cobalt and chromium concentrations, cystic fluid collection around the joint, and infection. Metal concentrations, US, and MARS-MRI contributed to the decision making regarding prosthesis revision.

CONCLUSION

Metal concentrations were significantly higher for the metal-on-metal prostheses than for the ceramic-on-ceramic. The clinical performance was good in all 3 prosthesis groups. Metal concentrations, US, and MARS-MRI findings were of use to identify hips needing revision. ID Number in ClinicalTrials.gov PRS: NCT00284674.

Long-term follow-up of 1217 consecutive short-stem total hip arthroplasty (THA): a retrospective single-center experience

BACKGROUND

An arthroplasty registry in Germany has been recently established but long-term results for most short-stem innovations are missing. Short-stem hip arthroplasty is usually indicated in young active patients. Our indication was extended to older age groups, femoral neck fractures (FNF), and dysplasia. We evaluated all total hip arthroplasties (THAs) in this population with a collum femoris preserving stem (CFP) performed from 2003 to 2013.

METHODS

A consecutive cohort of 1217 CFP THAs with a mean age of 68.7 years was followed retrospectively for a median of 4.8 years (patient follow-up interquartile range from 3.0 to 6.9 years). A questionnaire, which we used in two previous studies, was answered by 89.15% of patients and included information regarding complaints, grade of satisfaction, re-operations, and dislocation. Of the 1217 patients, 77 had died. Survival of the stem and the cup was assessed using a competing risks approach according to an Aalen-Johanson estimator with revision for septic or aseptic loosening or death as a competing endpoint.

RESULTS

Of the patients who answered the questionnaire, 92.5% had no complaints related to the procedures. In all 1217 patients, there were 43 revisions (4.2%) as follows: stem and cup revisions due to aseptic loosening of the stem (n = 10), infections (n = 6), pain (n = 4), or trauma (n = 3); cup revisions due to aseptic loosening (n = 3), dislocation (n = 5), and offset revisions (n = 12). Survivorship was 96% for the stem and 99% for the cup 9 years postoperatively. Statistical analysis confirmed a higher risk for revision in patients with a younger age (p = 0.033), male sex (p = 0.040), dysplasia (p = 0.032), and undersized or extra-large stems for stem revisions (p = 0.001) and female sex (p = 0.036) for cup revisions. FNF (p > 0.20) and age ≥ 80 years (p = 0.114) had no higher risk for loosening of the stem. Our data is also compared with the current literature, especially with the available CFP studies.

CONCLUSION

The survival rate of the CFP stem was as high as 96% after 9 years of followup which compares well-to-previously published long-term survival rates. There is no higher risk for revision in patients 80 years old or older and in cases with femoral neck fractures. The CFP preserves also allowed using standard stems in the rare cases of revision.

Trends in hip replacements between 1999 and 2012 in Sweden

National Registers document changes in the circumstance, practice, and outcome of surgery with the passage of time. In the context of total hip replacement (THR), registers can help elucidate the relevant factors that affect the clinical outcome. We evaluated the evolution of factors related to patient, surgical procedure, socio-economy, and various outcome parameters after merging databases of the Swedish Hip Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare. Data on 193,253 THRs (164,113 patients) operated between 1999 and 2012 were merged. We studied the evolution of surgical volume, patient demographics, socio-economic factors, surgical factors, length-of-stay, mortality rate, adverse events, re-operation and revision rates, and Patient Reported Outcome Measures (PROMs). Throughout this time period the majority of patients were operated on with a diagnosis of primary osteoarthritis. Comorbidity indices increased each year observed. The share of all-cemented implants has dropped from 92% to 68%. More than 88% of the bearings were metal-on-polyethylene. Length-of-stay decreased by 50%. There was a reduction in 30- and 90-day mortality. Re-operation and revision rates at 2 years are decreasing. The post-operative PROMs improved despite the observation of worse pre-operative pain scores getting over time. The demographics of patients receiving a THR, their comorbidities, and their primary diagnosis are changing. Notwithstanding these changes, outcomes like mortality, re-operations, revisions, and PROMs have improved. The practice of hip arthroplasty has evolved, even in a country such as Sweden that is considered to be conservative with regard taking on new surgical practices. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 36:432-442, 2018.

[Bernese periacetabular osteotomy. : Indications, technique and results 30 years after the first description]

The Bernese periacetabular osteotomy (PAO) is a surgical technique for the treatment of (1) hip dysplasia and (2) femoroacetabular impingement due to acetabular retroversion. The aim of the surgery is to prevent secondary osteoarthritis by improvement of the hip biomechanics. In contrast to other pelvic osteotomies, the posterior column remains intact with this technique. This improves the inherent stability of the acetabular fragment and thereby facilitates postoperative rehabilitation. The birth canal remains unchanged. Through a shortened ilioinguinal incision, four osteotomies and one controlled fracture around the acetabulum are performed. The direction of acetabular reorientation differs for both indications while the sequence of the osteotomies remains the same. This surgical approach allows for a concomitant osteochondroplasty in the case of an aspherical femoral head-neck junction. The complication rate is relatively low despite the complexity of the procedure. The key point for a successful long term outcome is an optimal reorientation of the acetabulum for both indications. With an optimal reorientation and a spherical femoral head, the cumulative survivorship of the hip after 10 years is 80-90 %. For the very first 75 patients, the cumulative 20-year survivorship was 60 %. The preliminary evaluation of the same series at a 30-year follow-up still showed a survivorship of approximately 30 %. The PAO has become the standard procedure for the surgical therapy of hip dysplasia in adolescents and adults.

The Corail stem as a reverse hybrid - survivorship and x-ray analysis at 10 years

BACKGROUND

The use of a cemented cup together with an uncemented stem in total hip arthroplasty (THA) has become popular in Norway and Sweden during the last decade. The results of this prosthetic concept, reverse hybrid THA have been sparsely described.We report our experience of reverse hybrid THA, using the Elite plus polyethylene cemented cup together with the Corail fully hydroxyapatite-coated uncemented stem and a 28-mm alumina ceramic head.

PATIENTS AND METHODS

132 consecutive reverse hybrid hip arthroplasties were performed from January 2000 to December 2003 in 126 patients with a mean age of 54.3 years (28-65). All patients were routinely reviewed at 3 months, 1, 5, 7 and 10 years postoperatively. At each follow-up patients were seen either by a consultant orthopaedic surgeon or a senior trainee. Anteroposterior pelvic and lateral x-rays of the hip were taken at each visit. To estimate the survival of the THAs we used the Kaplan-Meier method with 95% confidence interval (CI). Logistic regression analysis was performed to determine which factors affected the presence of radiolucency around the femoral stem.

RESULTS

The mean follow-up was 11.1 years (9.0-14.2). 1 patient was lost to follow-up, and 7 patients were deceased at the time of 10-year follow up. At 10 years 7 patients have had further surgery. 5 for infection, 1 periprosthetic femoral fracture and 1 heterotopic bone formation. All stems were classified as well fixed. 2 cups were defined as loose at 10 years. 1 patient is scheduled for revision the other refused revision. The clinical outcome and radiological findings were assessed in 123 hips. The mean Harris Hip Score was 94 (35-100) at 10 years and the mean WOMAC score was 89 (30.2-100).

CONCLUSIONS

We report good results with respect to clinical outcome and survival of the reverse hybrid concept in patients younger than 65. A successful outcome depends on meticulous preoperative planning, use of modern cementing techniques in the acetabulum and experience in implanting an uncemented stem.

Reverse hybrid total hip arthroplasty

Background and purpose - The use of a cemented cup together with an uncemented stem in total hip arthroplasty (THA) has become popular in Norway and Sweden during the last decade. The results of this prosthetic concept, reverse hybrid THA, have been sparsely described. The Nordic Arthroplasty Register Association (NARA) has already published 2 papers describing results of reverse hybrid THAs in different age groups. Based on data collected over 2 additional years, we wanted to perform in depth analyses of not only the reverse hybrid concept but also of the different cup/stem combinations used. Patients and methods - From the NARA, we extracted data on reverse hybrid THAs from January 1, 2000 until December 31, 2013. 38,415 such hips were studied and compared with cemented THAs. The Kaplan-Meier method and Cox regression analyses were used to estimate the prosthesis survival and the relative risk of revision. The main endpoint was revision for any reason. We also performed specific analyses regarding the different reasons for revision and analyses regarding the cup/stem combinations used in more than 500 cases. Results - We found a higher rate of revision for reverse hybrids than for cemented THAs, with an adjusted relative risk of revision (RR) of 1.4 (95% CI: 1.3-1.5). At 10 years, the survival rate was 94% (CI: 94-95) for cemented THAs and 92% (95% CI: 92-93) for reverse hybrids. The results for the reverse hybrid THAs were inferior to those for cemented THAs in patients aged 55 years or more (RR =1.1, CI: 1.0-1.3; p < 0.05). We found a higher rate of early revision due to periprosthetic femoral fracture for reverse hybrids than for cemented THAs in patients aged 55 years or more (RR =3.1, CI: 2.2-4.5; p < 0.001). Interpretation - Reverse hybrid THAs had a slightly higher rate of revision than cemented THAs in patients aged 55 or more. The difference in survival was mainly caused by a higher incidence of early revision due to periprosthetic femoral fracture in the reversed hybrid THAs.

Clinical epidemiology in the era of big data: new opportunities, familiar challenges

Routinely recorded health data have evolved from mere by-products of health care delivery or billing into a powerful research tool for studying and improving patient care through clinical epidemiologic research. Big data in the context of epidemiologic research means large interlinkable data sets within a single country or networks of multinational databases. Several Nordic, European, and other multinational collaborations are now well established. Advantages of big data for clinical epidemiology include improved precision of estimates, which is especially important for reassuring (“null”) findings; ability to conduct meaningful analyses in subgroup of patients; and rapid detection of safety signals. Big data will also provide new possibilities for research by enabling access to linked information from biobanks, electronic medical records, patient-reported outcome measures, automatic and semiautomatic electronic monitoring devices, and social media. The sheer amount of data, however, does not eliminate and may even amplify systematic error. Therefore, methodologies addressing systematic error, clinical knowledge, and underlying hypotheses are more important than ever to ensure that the signal is discernable behind the noise.

One-third of Hips After Periacetabular Osteotomy Survive 30 Years With Good Clinical Results, No Progression of Arthritis, or Conversion to THA

BACKGROUND

Since its first description in 1984, periacetabular osteotomy (PAO) has become an accepted treatment for hip dysplasia. The 30-year survivorship with this procedure has not been reported. Because these patients are often very young at the time of surgery, long-term followup and identification of factors associated with poor outcome could help to improve patient selection.

QUESTIONS/PURPOSES

Looking at the initial group of patients with hip dysplasia undergoing PAO at the originator's institution, we asked: (1) What is the cumulative 30-year survival rate free from conversion to THA, radiographic progression of osteoarthritis, and/or a Merle d'Aubigné-Postel score < 15? (2) Did hip function improve and pain decrease? (3) Did radiographic osteoarthritis progress? (4) What are the factors associated with one or more of the three endpoints: THA, radiographic progression of osteoarthritis, and/or Merle d'Aubigné-Postel score < 15?

METHODS

We retrospectively evaluated the first 63 patients (75 hips) who underwent PAO for hip dysplasia between 1984 and 1987. At that time, hip dysplasia was the only indication for PAO and no patients with acetabular retroversion, the second indication for a PAO performed today, were included. During that period, no other surgical treatment for hip dysplasia in patients with closed triradiate cartilage was performed. Advanced osteoarthritis (≥ Grade 2 according to Tönnis) was present preoperatively in 18 hips (24%) and 22 patients (23 hips [31%]) had previous femoral and/or acetabular surgery. Thirty-nine patients (42 hips [56%]) were converted to a THA and one patient (one hip [1%]) had hip fusion at latest followup. Two patients (three hips [4%]) died from a cause unrelated to surgery 6 and 16 years after surgery with an uneventful followup. From the remaining 21 patients (29 hips), the mean followup was 29 years (range, 27-32 years). Of those, five patients (six hips [8%]) did not return for the most recent followup and only a questionnaire was available. The cumulative survivorship of the hip according to Kaplan-Meier was calculated if any of the three endpoints, including conversion to THA, progression of osteoarthritis by at least one grade according to Tönnis, and/or a Merle d'Aubigné-Postel score < 15, occurred. Hip pain and function were assessed with Merle d'Aubigné-Postel score, Harris hip score, limp, and anterior and posterior impingement tests. Progression of radiographic osteoarthritis was assessed with Tönnis grades. A Cox regression model was used to calculate factors associated with the previously defined endpoints.

RESULTS

The cumulative survivorship free from conversion to THA, radiographic progression of osteoarthritis, and/or Merle d'Aubigné-Postel score < 15 was 29% (95% confidence interval, 17%-42%) at 30 years. No improvement was found for either the Merle d'Aubigné-Postel (15 ± 2 versus 16 ± 2, p = 0.144) or Harris hip score (83 ± 11 versus 85 ± 17, p = 0.602). The percentage of a positive anterior impingement test (39% versus 14%, p = 0.005) decreased at 30-year followup, whereas the percentage of a positive posterior impingement test (14% versus 3%, p = 0.592) did not decrease. The percentage of positive limp decreased from preoperatively 66% to 18% at 30-year followup (p < 0.001). Mean osteoarthritis grade (Tönnis) increased from preoperatively 0.8 ± 1 (0-3) to 2.1 ± 1 (0-3) at 30-year followup (p < 0.001). Ten factors associated with poor outcome defined as THA, radiographic progression of osteoarthritis, and/or Merle d'Aubigné-Postel score < 15 were found: preoperative age > 40 years (hazard ratio [HR] 4.3 [3.7-4.9]), a preoperative Merle d'Aubigné-Postel score < 15 (HR 4.1 [3.5-4.6]), a preoperative Harris hip score < 70 (HR 5.8 [5.2-6.4]), preoperative limp (HR 1.7 [1.4-1.9]), presence of a preoperative positive anterior impingement test (HR 3.6 [3.1-4.2]), presence of a preoperative positive posterior impingement test (HR 2.5 [1.7-3.2]), a preoperative internal rotation of < 20° (HR 4.3 [3.7-4.9]), a preoperative Tönnis Grade > 1 (HR 5.7 [5.0-6.4]), a postoperative anterior coverage > 27% (HR 3.2 [2.5-3.9]), and a postoperative acetabular retroversion (HR 4.8 [3.4-6.3]).

CONCLUSIONS

Thirty years postoperatively, 29% of hips undergoing PAO for hip dysplasia can be preserved, but more than 70% will develop progressive osteoarthritis, pain, and/or undergo THA. Periacetabular osteotomy is an effective technique to treat symptomatic hip dysplasia in selected and young patients with closed triradiate cartilage. Hips with advanced joint degeneration (osteoarthritis Tönnis Grade ≥ 2) should not be treated with PAO. Postoperative anterior acetabular overcoverage or postoperative acetabular retroversion were associated with decreased joint survival.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Survival of uncemented cups from a single manufacturer implanted from 1985 to 2013: Finnish Arthroplasty Register data

INTRODUCTION

Total hip arthroplasty (THA) with uncemented implants has been a relatively common procedure in Finland during the recent decades. The most common brand of uncemented implants was chosen for further analysis to study the survivorship of this uncemented cup design in comparison to cemented references.

PATIENTS, MATERIALS AND METHODS

Since 1980, The Finnish Arthroplasty Register has collected information on THAs on a national level. This study was based on information of THAs recorded in the Finnish Arthroplasty Register from 1985 to 2013. If patient had undergone bilateral THA, only the first one was included. Altogether, 49,289 THAs were included.

RESULTS

The overall 10-year implant survivorship of uncemented implants was 84.3% (95% CI 83.5-85.0%) and of cemented implants 90.6% (90.2-90.0%). The 10-year survival of the contemporary uncemented implants was 90.8% (94.0-95.5%) and 88.5% (84.2-91.7%). The most recently introduced uncemented cup designs had good survivorship rates at 5 years; 10-year survival data are not yet available.

CONCLUSIONS

We found that modern uncemented cup designs may provide good long-term survivorship rates comparable with the gold standard of cemented cups. However, polyethylene wear, liner problems and periosthetic osteolysis may still occur, also with modern uncemented acetabular components.

Perioperative Periprosthetic Fractures Associated With Primary Total Hip Arthroplasty

BACKGROUND

Periprosthetic fracture (PPF) is a rare but devastating complication of primary total hip arthroplasty (THA). While PPF is associated with increased morbidity and mortality, early revision rate, and poor patient outcome, there is a paucity of data on patient and hospital-dependent risk factors. Using a large administrative database, we investigated epidemiology and the risk factors associated with perioperative PPF after primary THA.

METHODS

We performed a retrospective review of the National Inpatient Sample records from 2006 to 2011 and identified 1062 PPFs of 1,187,969 patients using International Classification of Diseases, Ninth Revision code for PPF (996.44). We then analyzed sociodemographic characteristics, comorbidities, and hospital characteristics of our study population.

RESULTS

The overall incidence of PPF in National Inpatient Sample database was 0.089% (8.9 per 10,000 THAs). Patient-dependent risk factors were: female (odds ratio [OR] 1.93, 95% confidence interval [CI] 1.67-2.22), low household income (OR 1.4, 95% CI 1.18-1.65), Medicaid (OR 1.89, 95% CI 1.39-2.57), and uninsured (OR 2.74, 95% CI 1.63-4.61). Patients with malnutrition and hemiparesis/hemiplegia were associated 10-fold and 6-fold risk of PPF. Nonteaching hospitals (OR 1.15, 95% CI 1.01-1.32), hospitals in northeast (OR 1.29, 95% CI 1.04-1.59), and rural hospitals (OR 1.27, 95% CI 1.06-1.53) had higher incidence of PPF.

CONCLUSION

Our study demonstrates that the incidence of PPF was low in our study population, and greater awareness is needed when performing primary THAs in patients with risk factors identified in our study to prevent PPF.

A decade of the Catalonian Arthroplasty Register (RACat): Variability, exhaustivity, and survival of prostheses between 2005 and 2014

BACKGROUND AND AIM

The Catalonian Arthroplasty Register (RACat) is a public health-based population register used to analyse and evaluate hip and knee replacements in Catalonia. The aim of this study is to present the outcomes after 10 years in operation (January 2005-December 2014).

METHODOLOGY

Using the information from the RACat and the minimum basic data set at hospital discharge, an analysis was made of the quality and exhaustivity of the data, as well as a descriptive analysis of the patients, prostheses, and care process. Survival was also analysed by calculating the accumulated incidence of revisions (according to the cause of intervention in hip replacements and conservation or sacrifice of the posterior cruciate ligament in knee replacement). The relationship between revision risk and the fixation technique of the prosthesis is also analysed, using competitive risk models adjusted for gender, age, and comorbidities.

RESULTS

The main reason for the primary hip and knee replacement surgery was arthrosis. The accumulated incidence of revisions at 10 years was 3.9% in hip replacements caused by arthrosis, and 2.3% in those caused by fracture. Conservation of the posterior cruciate ligament was achieved in 4.4% of knee replacements, with sacrifice in 5.1%.

DISCUSSION

The RACat is consolidated as a tool for the evaluation of joint replacements, with great potential in the analysis of medium and long-term efficacy, the study of the variability in clinical practice, and post-marketing surveillance.

Is it feasible to merge data from national shoulder registries? A new collaboration within the Nordic Arthroplasty Register Association

BACKGROUND

The Nordic Arthroplasty Register Association was initiated in 2007, and several papers about hip and knee arthroplasty have been published. Inspired by this, we aimed to examine the feasibility of merging data from the Nordic national shoulder arthroplasty registries by defining a common minimal data set.

METHODS

A group of surgeons met in 2014 to discuss the feasibility of merging data from the national shoulder registries in Denmark, Norway, and Sweden. Differences in organization, definitions, variables, and outcome measures were discussed. A common minimal data set was defined as a set of variables containing only data that all registries could deliver and where consensus according to definition of the variables could be made.

RESULTS

We agreed on a data set containing patient-related data (age, gender, and diagnosis), operative data (date, arthroplasty type and brand), and data in case of revision (date, reason for revision, and new arthroplasty brand). From 2004 to 2013, there were 19,857 primary arthroplasties reported. The most common indications were osteoarthritis (35%) and acute fracture (34%). The number of arthroplasties and especially the number of arthroplasties for osteoarthritis have increased in the study period. The most common arthroplasty type was total shoulder arthroplasty (34%) for osteoarthritis and stemmed hemiarthroplasty (90%) for acute fractures.

CONCLUSION

We were able to merge data from the Nordic national registries into 1 common data set; however, the set of details was reduced. We found considerable differences between the 3 countries regarding incidence of shoulder arthroplasty, age, diagnoses, and choice of arthroplasty type and brand.

Implant survival of the most common cemented total hip devices from the Nordic Arthroplasty Register Association database

Background and purpose - According to previous Nordic Arthroplasty Register Association (NARA) data, the 10-year implant survival of cemented total hip arthroplasties (THAs) is 94% in patients aged 65-74 and 96% in patients aged 75 or more. Here we report a brand-level comparison of cemented THA based on the NARA database, which has not been done previously. Patients and methods - We determined the rate of implant survival of the 9 most common cemented THAs in the NARA database. We used Kaplan-Meier analysis with 95% CI to study implant survival at 10 and 15 years, and Cox multiple regression to assess survival and hazard ratios (HRs), with revision for any reason as endpoint and with adjustment for age, sex, diagnosis, and femoral head material. Results - Spectron EF THA (89.9% (CI: 89.3-90.5)) and Elite THA (89.8% (CI: 89.0-90.6)) had the lowest 10-year survivorship. Lubinus (95.7% survival, CI: 95.5-95.9), MS 30 (96.6%, CI: 95.8-97.4), and C-stem THA (95.8%, CI: 94.8-96.8) had a 10-year survivorship of at least 95%. Lubinus (revision risk (RR) = 0.77, CI: 0.73-0.81), Müller (RR =0.83, CI: 0.70-0.99), MS-30 (RR =0.73, CI: 0.63-0.86), C-stem (RR =0.70, CI: 0.55-0.90), and Exeter Duration THA (RR =0.84, CI: 0.77-0.90) had a lower risk of revision than Charnley THA, the reference implant. Interpretation - The Spectron EF THA and the Elite THA had a lower implant survival than the Charnley, Exeter, and Lubinus THAs. Implant survival of the Müller, MS 30, CPT, and C-stem THAs was above the acceptable limit for 10-year survival.

[Predictive factors of aseptic loosening of cemented total hip prostheses]

Introduction

Le descellement aseptique constitue la principale complication à long terme et signe la faillite de la prothèse totale de hanche. Les causes de descellement aseptique sont multiples et souvent intriquées. Le mal positionnement des implants reste le facteur le plus incriminé. D’autres facteurs liés au patient et à la prothèse prédisposent également au descellement mais à des degrés divers.

Méthodes

A travers une étude rétrospective portant sur 64 descellements aseptiques de prothèse totale de hanche, nous avons tenté d’individualiser les facteurs de descellement lié au patient, au type d’implant et à la technique chirurgicale et d’en dégager les recommandations visant à minimiser ce risque. Il s’agissait d’une étude rétrospective analytique portant sur 64 descellements aseptiques. La classification utilisée est celle de la Société Française de Chirurgie Orthopédique et Traumatologique.

Résultats

La moyenne d’âge au moment de la première arthroplastie était de 40 ans. Elle était de 62 au moment du descellement. La tige type Charnley a été implantée dans 55 cas, celle de type Muller dans 9 cas. La pièce cotyloïdienne a été bien positionnée dans 69% des cas avec une inclinaison moyenne de 47,8°. Les tiges étaient remplissantes dans 86% des cas avec un cimentage Grade A dans 60% des cas. Le délai moyen de la survenue du descellement était de 12 ans. 72% des prothèses avaient une survie supérieure à 10 ans. L’analyse statistique des résultats a individualisé les facteurs de risque du descellement que sont: L’âge, l’indexe de masse corporelle, le niveau d’activité, l’inclinaison de la cupule, le déport fémoral et la qualité du cimentage.

Conclusion

Une réduction significative des descellements aseptiques des prothèses totales de hanche ne pourra être obtenue que par une plus grande rigueur dans la sélection des patients, une plus grande sûreté dans l’acte technique et un meilleur choix de l’implant à poser.

Cementless Total Hip Arthroplasty With Metasul Bearings Provides Good Results in Active Young Patients: A Concise Followup

BACKGROUND

A primary concern of younger, more active patients who have undergone total hip arthroplasty (THA) is the longevity of the implant. Cementless fixation and hard-on-hard bearings are recognized as options to enhance THA durability. Earlier, we published a series of 83 cementless primary THAs using 28-mm metal-on-metal (MoM) bearings in patients aged 50 years or younger; here we provide concise followup on that same group after an additional 8-year survey period.

QUESTIONS/PURPOSES

(1) What is the long-term survivorship of cementless primary THA using 28-mm MoM bearings in patients aged 50 years or younger? (2) What are the clinical and radiographic results of cementless THA in this active patient population? (3) Can any of the observed implant failures or adverse events be attributed to the metallic nature of the bearing couple?

METHODS

We retrospectively reviewed 83 cementless THAs performed in three institutions over a decade (1995-2004) in 68 patients with 28-mm MoM articulation. All patients (15 bilateral) had a median age of 42 years (range, 24-50 years) at the time of the index procedure and 56 of them (82% [70 hips]) had activity level graded Devane 4 or 5 before significant hip pain. A 28-mm Metasul™ articulation was used with an Alloclassic-SL™ cementless stem in all cases paired with three different cementless titanium acetabular components (one threaded and two press-fit cups) from the same manufacturer. Survivorship analysis was calculated according to Dobbs life table, patient clinical results were evaluated with use of the Postel-Merle d'Aubigné scoring system, radiographic analysis was performed by independent observers, and cobalt level was determined in whole blood.

RESULTS

The 15-year survivorship (33 hips at risk) for revision for any reasons (four hips) and for aseptic loosening (one hip) was 96% (95% confidence interval [CI], 81%-99%) and 99% (95% CI, 85%-99.9%), respectively. The median Merle d'Aubigné-Postel score remained stable at 17 points (range, 10-18). Thus far, we have not observed pseudotumors or other adverse reactions to metallic debris. Eight hips have undergone reoperation: trochanteric suture removal (one), psoas tendon impingement (two), and five revisions for periprosthetic fracture (one), late infection (two), acetabular osteolysis (one, as a result of polyethylene backside wear), and one hydroxyapatite-coated cup for aseptic loosening. None of the complications, failures, or revisions observed so far could directly be related to the metallic nature of the 28-mm Metasul bearings used in this selected group of patients.

CONCLUSIONS

The current survey at 13-year median followup has not yet indicated any long-term deleterious effects related to dissemination of metallic ions. Two senior authors continue to use 28- or 32-mm Metasul™ bearings with cementless THA components in young and active patient populations. Longer followup with a more sophisticated imaging study is necessary to confirm this so far positive report.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Functional outcomes of total hip arthroplasty in patients aged 30 years or less: a systematic review and meta-analysis

INTRODUCTION

Young adult hip surgery is a growing subspecialty. Increasingly total hip arthroplasty (THA) is offered to patients aged 30 or less suffering from end-stage hip arthropathy from a variety of congenital, developmental and acquired conditions. There is a paucity of evidence to advise such patients and surgeons alike on the functional outcomes of THA in this age group, as individual studies tend to include small cohorts.

METHODS

A systematic review and meta-analysis was performed to assess whether THA in patients aged 30 years or less provides significant functional improvement. The primary outcome measure was change in Harris Hip Score. Secondary outcome measures were implant survivorship and the effect of fixation type and bearing surface.

RESULTS

The results of 743 primary THA procedures were included. Weighted mean patient age was 22.7 years. Harris Hip Score improved by a weighted mean difference of 42.17 points out of 100 (95% confidence interval, 36.48-47.86 points, p&lt;0.001) after THA at a weighted mean follow-up of 8.4 years. Pooled revision rate was 5.0% for the same time period.

CONCLUSIONS

This is the largest review to date of THA in patients aged 30 or less. The results show significant functional improvement measured by Harris Hip Score. The revision rate of 5% at 8.4 years is comparable to the general THA population. This contrasts high revision rates reported in older reviews of the literature, suggesting adoption of improved techniques and implants in the more recent literature.

Association between hospital procedure volume and risk of revision after total hip arthroplasty: a population-based study within the Nordic Arthroplasty Register Association database

OBJECTIVE

Outcome after total hip arthroplasty (THA) depends on several factors related to the patient, the surgeon and the implant. It has been suggested that the annual number of procedures per hospital affects the prognosis. We aimed to examine if hospital procedure volume was associated with the risk of revision after primary THA in the Nordic countries from 1995 to 2011.

DESIGN

The Nordic Arthroplasty Register Association database provided information about primary THA, revision and annual hospital volume. Hospitals were divided into five volume groups (1-50, 51-100, 101-200, 201-300, >300). The outcome of interest was risk of revision 1, 2, 5, 10 and 15 years after primary THA. Multivariable regression was used to assess the relative risk (RR) of revision.

RESULTS

417,687 THAs were included. For the 263,176 cemented THAs no differences were seen 1 year after primary procedure. At 2, 5, 10 and 15 years the four largest hospital volume groups had a reduced risk of revision compared to group 1-50. After 10 years RR was for volume group 51-100 0.79 (CI 0.65-0.95), group 101-200 0.76 (CI 0.61-0.95), group 201-300 0.74 (CI 0.57-0.96) and group >300 0.57 (CI 0.46-0.71). For the uncemented THAs an association between hospital volume and risk of revision were only present for hospitals producing 201-300 THAs per year, beginning at years 2 through 5 and in all subsequent time intervals to 15 years.

CONCLUSION

Hospital procedure volume was associated with a long term risk of revision after primary cemented THA. Hospitals operating 50 procedures or less per year had an increased risk of revision after 2, 5, 10 and 15 years follow up.

Do Rerevision Rates Differ After First-time Revision of Primary THA With a Cemented and Cementless Femoral Component?

BACKGROUND

Worldwide use of cementless fixation for total hip arthroplasty (THA) is on the rise despite some evidence from the world's registries suggesting inferior survivorship compared with cemented techniques. The patterns of bone loss associated with failed cementless and cemented THAs may prejudice the results of future revision procedures; however, this has not been documented.

QUESTIONS/PURPOSES

The purpose of this study was to compare (1) the risk for rerevision of first revision THA; (2) the patterns of femoral bone loss at the time of first revision of primary THA; (3) the reasons for first revision of primary THA; and (4) the time to first revision of primary THA between primary cementless and cemented femoral components.

METHODS

Primary THAs with cemented (n = 1791) and uncemented (n = 805) femoral components that subsequently sustained first revision of the femoral component were identified from the Danish Hip Arthroplasty Registry (DHR). As of 2012, 120,988 primary THAs and 19,282 revisions were registered in the DHR with completeness of 97% and 90% for primary and revision THA, respectively. Median followup for revisions of primary THA with cemented and cementless femoral component was 4 years (range, 0-17 years) and 2 years (range, 0-16 years), respectively. Survival of first revision THA, with second revision of the femur as outcome, was evaluated using hazard ratios (HRs) with 95% confidence interval (CI) adjusting for potential confounding. All patient- and surgery-related data are collected from Danish medical databases. Recording of bone defects in the DHR is based on surgeons' intraoperative findings.

RESULTS

With the numbers studied, we found no differences in the risk of second revision between the overall cohort between cementless and cemented techniques (HR, 1.32; 95% CI, 0.97-1.80; p = 0.076); however, a second revision for any reason was more likely in patients < 70 years old in whom the index arthroplasty was performed using a cementless technique (HR, 1.48; 95% CI, 1.01-2.17; p = 0.046). Increasingly severe femoral bone defects of type II (30% [532 of 1791] versus 13% [104 of 805]; p < 0.001) type III (11% [200 of 1791] versus 2% [12 of 805]; p < 0.001) and type IV (1% [26 of 1791] versus 0.4% [three of 805]; p = 0.016) were more frequent at revisions of cemented femoral components compared with cementless femoral components. Indications for first revision differed between primary cemented and uncemented femoral components, because a larger proportion of cemented femoral components was revised as a result of aseptic loosening compared with cementless femoral components (74% [1329 of 1791] versus 25% [197 of 805]; p < 0.001), whereas a larger proportion of cementless femoral components was revised as a result of a fracture compared with cemented femoral components (46% [371 of 805] versus 10% [168 of 1791]; p < 0.001). Failure before 5 years was more likely in cementless femoral components than cemented femoral components (91% [733 of 805] versus 44% [749 of 1791], p < 0.001).

CONCLUSIONS

We found no differences in the risk of second revision in the overall cohort between cementless and cemented techniques; however, we observed an increased risk for rerevision THA performed on patients < 70 years whose index THAs were performed using cementless components when looking at all causes for revision, even after adjusting for the most likely confounding factors. Our data suggest that increased use of cementless fixation in primary THA may lead to inferior survivorship of first revision THA.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Are younger patients undergoing THA appropriately characterized as active?

BACKGROUND

Surgeons perform THA to address a variety of conditions in younger patients, including osteoarthritis (OA), osteonecrosis, inflammatory arthritis, and congenital deformities. Younger patients aged 50 years or younger have been characterized as active in the literature, but a direct relationship between age and activity level has not been well substantiated. Younger patients with OA may engage in higher activity levels; however, associated medical conditions in patients with other surgical indications may not support a generalization that age is a surrogate for activity level. We recently evaluated these issues in younger patients undergoing total knee arthroplasty (TKA) and noted that the majority would not be considered active. Given this observation, we considered whether younger patients undergoing THA are characterized by high activity levels, which is relevant to understanding the long-term risk of wear-related failures.

QUESTIONS/PURPOSES

(1) Do demographic features of younger patients undergoing THA support high activity expectations? (2) Do preoperative or postoperative functional activity measures support projections that younger patients are active after THA?

METHODS

We retrospectively compared demographic characteristics and functional activity profiles (as determined by preoperative and postoperative UCLA activity scores, Harris hip scores [HHS], and SF-12 and WOMAC physical function subscores) of 704 patients who had undergone THA and were aged younger than 50 years (822 hips) with those of 484 patients (516 hips) aged between 65 and 75 years, who had undergone THA, with a minimum followup at 1 year after surgery (range, 12-160 months).

RESULTS

Compared with patients aged 65 to 75 years, younger patients undergoing THA were more often men (51%, 95% confidence interval [CI], 48.8%-53.2% versus 40%, 95% CI, 37.1%-42.9% women; p < 0.01) or had undergone surgery for osteonecrosis (29% versus 4%; 95% CI, 2.8%-5.2%; p < 0.001). Postoperative HHS, SF-12, and WOMAC scores were not appreciably different between the two patient groups. Compared with older patients, younger patients with OA had higher preoperative (5.0 ± 2.5 versus 3.9 ± 2.0, p < 0.001) and postoperative UCLA activity scores (6.8 ± 2.1 versus 5.3 ± 1.9, p < 0.001). Younger patients with diagnoses other than OA had slightly higher mean postoperative UCLA activity scores than older patients (6.0 ± 2.3 versus 5.3 ± 1.9; p < 0.001). Two hundred fifty-nine of 704 younger patients undergoing THA (37%; 95% CI, 34.9%-39.1%) returned to impact activity compared with 75 of 484 older patients undergoing THA (15.5%; 95% CI, 13.3%-17.7%) (p < 0.001).

CONCLUSIONS

Younger patients with OA are likely to return to high levels of activity after surgery, which may impact long-term wear-related implant survivorship. High activity levels are less common among younger patients with diagnoses other than OA. Age is not the ideal surrogate for activity level in patients considering THA; instead, specific activity-level measures should be used when discussing patient expectations pertaining to postoperative activity levels after arthroplasty.

LEVEL OF EVIDENCE

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

Systematic review of literature of cemented femoral components: what is the durability at minimum 20 years followup?

BACKGROUND

Cemented femoral total hip arthroplasty may be one of the most successful surgical interventions of all time. However, although results are very encouraging over the early to mid-term followup, relatively few studies have analyzed the durability of these implants beyond 20 years followup. To evaluate the performance of contemporary implants, it is important to understand how previous implants perform at 20 or more years of followup; one way to do this is to aggregate the available data in the form of a systematic review.

QUESTIONS/PURPOSES

(1) How durable is cemented femoral fixation in the long term (minimum 20-year followup) with respect to aseptic loosening? (2) Is the durability of cemented femoral fixation dependent on age of the patient? (3) Are the long-term results of the cemented femoral fixation dependent on any identifiable characteristics of the prosthesis such as surface finish?

METHODS

A systematic review was performed to identify long-term studies of cemented femoral components. After application of inclusion and exclusion criteria to 1228 articles found with a search in PubMed and EMBASE, 17 studies with a minimum of 20-year followup on cemented femoral components were thoroughly analyzed in an attempt to answer the questions of this review. The quality of the studies reviewed was assessed with the Methodological Index for Nonrandomized Studies (MINORS) instrument. All studies were case series and cohort sizes ranged from 110 to 2000 hips for patients older than 50 years of age and 41 to 93 hips for patients younger than 50 years at the time of surgery.

RESULTS

Among the six case series performed in patients older than 50 years of age, survivorship for aseptic loosening of the femoral component ranged from 86% to 98% at 20 years followup. There were no obvious differences for younger patients when analyzing the five studies in patients younger than age 50 years in which survivorship free from aseptic loosening for these studies ranged from 77% at 20 years in one study and 68% to 94% at 25 years in the other studies. Although data pooling could not be performed because of heterogeneity of the studies included here, it appeared that stems with a rougher surface finish did not perform as well as polished stems; survivorship of stems with rougher surface finishes varied between 86% and 87%, whereas those with smoother finishes ranged between 93.5% and 98% at 20 years.

CONCLUSIONS

Excellent long-term fixation in both older and younger patients can be obtained with cemented, polished femoral stems. These results provide material for comparison with procedures performed with newer cementing techniques and newer designs, both cemented and cementless, at this extended duration of followup.