Trends in hip replacements between 1999 and 2012 in Sweden

Aspirin or enoxaparin for VTE prophylaxis after primary partial, total or revision hip or knee arthroplasty: A secondary analysis from the CRISTAL cluster randomized trial

BACKGROUND

This study compares aspirin to enoxaparin for symptomatic VTE prophylaxis within 90 days of any type of hip or knee arthroplasty performed for any diagnosis, in patients enrolled in the CRISTAL trial.

MATERIALS AND METHODS

CRISTAL was a cluster-randomised crossover, registry-nested non-inferiority trial across 31 hospitals in Australia. The primary publication was restricted to patients undergoing primary total hip or knee arthroplasty for a diagnosis of osteoarthritis. This report includes all enrolled patients undergoing hip or knee arthroplasty procedures (partial or total, primary or revision) performed for any indication. Hospitals were randomized to administer patients aspirin (100mg daily) or enoxaparin (40mg daily), for 35 days after hip arthroplasty and 14 days after knee arthroplasty. Crossover occurred after the patient enrolment target had been met for the first group. The primary outcome was symptomatic VTE within 90 days. Analyses were performed by randomization group.

RESULTS

Between April 20, 2019 and December 18, 2020, 12384 patients were enrolled (7238 aspirin group and 5146 enoxaparin). Of these, 6901 (95.3%) given aspirin and 4827 (93.8%) given enoxaparin (total 11728, 94.7%) were included in the final analyses. Within 90 days, symptomatic VTE occurred in 226 (3.27%) aspirin patients and 85 (1.76%) enoxaparin patients, significant for the superiority of enoxaparin (estimated treatment difference 1.85%, 95% CI 0.59% to 3.10%, p = 0.004). Joint-related reoperation within 90 days was lower in the enoxaparin group (109/4827 (2.26%) vs 171/6896 (2.47%) with aspirin, estimated difference 0.77%; 95% CI 0.06% to 1.47%, p = 0.03). There were no significant differences in the other secondary outcomes.

CONCLUSION

In patients undergoing hip or knee arthroplasty (of any type, performed for any indication) enrolled in the CRISTAL trial, aspirin compared to enoxaparin resulted in a significantly higher rate of symptomatic VTE and joint-related reoperation within 90 days. These findings extend the applicability of the CRISTAL trial results.

TRIAL REGISTRATION

Anzctr.org.au, identifier: ACTRN12618001879257.

The utility of cemented femoral stems in modern THA: a 10-year comparative analysis of the Charnley and Exeter stems

BACKGROUND

Total hip replacement (THR) is one of the most common surgical procedures performed worldwide. The controversy surrounding the relative merits of a cemented composite beam or cemented taper-slip stem in total hip replacement continues. Our aims primarily were to assess the 10-year outcomes of cemented stems using Charnley and Exeter prostheses with regional registry data and secondarily to assess the main predictors of revision.

METHODS

We prospectively collected registry data for procedures performed between January 2005 and June 2008. Only cemented Charnley and Exeter stems were included. Patients were prospectively reviewed at 6 months, 2, 5 and 10 years. The primary outcome measure was a 10-year all-cause revision. Secondary outcomes included 're-revision', 'mortality' and functional 'Western Ontario and McMaster Universities Osteoarthritis Index' (WOMAC) scores.

RESULTS

We recorded a total of 1351 cases in the cohort, 395 Exeter and 956 Charnley stems. The overall all-cause revision rate at 10 years was 1.6%. The revision rate for Charnley stem was 1.4% and 2.3% revision rate for all Exeter stems with no significant difference noted between the two cohorts (p = 0.24). The overall time to revision was 38.3 months. WOMAC scores at 10 years were found to be insignificantly higher for Charnley stems (mean 23.8, σ = 20.11) compared to Exeter stems (mean 19.78, σ = 20.72) (p = 0.1).

CONCLUSION

There is no significant difference between cemented Charnley and Exeter stems; they both perform well above the international average. The decline in the use of cemented THA is not fully supported by this regional registry data.

The True Dislocation Incidence following Elective Total Hip Replacement in Sweden: How Does It Relate to the Revision Rate?

(1) Background: The true dislocation incidence following THA is difficult to ascertain in population-based cohorts. In this study, we explored the cumulative dislocation incidence (CDI), the relationship between the incidence of dislocation and revision surgery, patient- and surgery-related factors in patients dislocating once or multiple times, and differences between patients being revised for dislocation or not. (2) Methods: We designed an observational longitudinal cohort study linking registers. All patients with a full dataset who underwent an elective unilateral THA between 1999 and 2014 were included. The CDI and the time from the index THA to the first dislocation or to revision were estimated using the Kaplan-Meier (KM) method, giving cumulative dislocation and revision incidences at different time points. (3) Results: 136,810 patients undergoing elective unilateral THA were available for the analysis. The 30-day CDI was estimated at 0.9% (0.9-1.0). The revision rate for dislocation throughout the study period remained much lower. A total of 51.2% (CI 49.6-52.8) suffered a further dislocation within 1 year. Only 10.9% of the patients with a dislocation within the first year postoperatively underwent a revision for dislocation. (4) Discussion: The CDI after elective THA was expectedly considerably higher than the revision incidence. Further studies investigating differences between single and multiple dislocators and the criteria by which patients are offered revision surgery following dislocation are urgently needed.

Management of acetabular bone loss in revision total hip replacement: a narrative literature review

Background and Objective

Due to growing numbers of primary total hip replacement (THR), the revision THR burden is also increasing. Common indications for revision are osteolysis, infection, instability, and mechanical failure of implants, which can cause acetabular bone loss. Massive acetabular bone defects and pelvic discontinuity are extremely challenging problems. Many techniques have been utilized to address bone loss while maintaining a stable revision THR. Structural allografts, cemented prosthesis, reconstruction cages, and custom triflanged implants have all been used successfully albeit with relatively high complications rates. We have tried to highlight emerging trends to utilize Custom Made Monoflange or Triflange Acetabular Components to reconstruct massive acetabular defects with favourable midterm implant survival, better functional outcomes, relatively lesser complications, and almost similar cost of prosthesis as compared to conventional reconstruction techniques. However, long-term data and study is still recommended to draw a definitive conclusion.

Methods

In this narrative review article, we searched PubMed and Cochrane for studies on managing acetabular bone loss in revision THR with a focus on recent literature for mid to long-term outcomes and compared results from various studies on different reconstruction methods.

Key Content and Findings

Hemispherical cementless acetabular prosthesis with supplemental screws are commonly utilized to manage mild to moderate acetabular bone loss. Recent trends have shown much interest and paradigm shift in patient specific custom triflange acetabular components (CTAC) for reconstructing massive acetabular defects and pelvic discontinuity. Studies have reported high patient satisfaction, improved patient reported daily functioning, high mid-term implant survival, similar complications, and encouraging all cause re-revision rate. However, more prospective and quality studies with larger sample sizes are needed to validate the superiority of CTACs over conventional acetabular implants.

Conclusions

There is no consensus regarding the best option for reconstructing massive acetabular defects. Thorough preoperative workup and planning is an absolute requirement for successful revision THR. While most of the moderate acetabular bone loss can be managed with cementless hemispherical acetabular shells with excellent long-term outcomes, reconstructing massive acetabular bone defects in revision THR remains a challenge. Depending on the size and location of the defect, various constucts have demonstrated long-term success as discussed in this review, but complications are not negligible. CTACs provide a treatment for massive bone loss that may be otherwise difficult to achieve anatomic stability with other constructs. Although long-term data is sparse, the cost and complication rate is comparable to other reconstruction methods.

Effect of Aspirin vs Enoxaparin on 90-Day Mortality in Patients Undergoing Hip or Knee Arthroplasty: A Secondary Analysis of the CRISTAL Cluster Randomized Trial

Importance

Ischemic heart disease remains the leading cause of mortality following hip and knee arthroplasty. Due to its antiplatelet and cardioprotective properties, aspirin has been proposed as an agent that could reduce mortality when used as venous thromboembolism (VTE) prophylaxis following these procedures.

Objective

To compare aspirin with enoxaparin in reducing 90-day mortality for patients undergoing hip or knee arthroplasty procedures.

Design, Setting, and Participants

This study was a planned secondary analysis of the CRISTAL cluster randomized, crossover, registry-nested trial performed across 31 participating hospitals in Australia between April 20, 2019, and December 18, 2020. The aim of the CRISTAL trial was to determine whether aspirin was noninferior to enoxaparin in preventing symptomatic VTE following hip or knee arthroplasty. The primary study restricted the analysis to patients undergoing total hip or knee arthroplasty for a diagnosis of osteoarthritis only. This study includes all adult patients (aged ≥18 years) undergoing any hip or knee arthroplasty procedure at participating sites during the course of the trial. Data were analyzed from June 1 to September 6, 2021.

Interventions

Hospitals were randomized to administer all patients oral aspirin (100 mg daily) or subcutaneous enoxaparin (40 mg daily) for 35 days after hip arthroplasty and 14 days after knee arthroplasty procedures.

Main Outcomes and Measures

The primary outcome was mortality within 90 days. The between-group difference in mortality was estimated using cluster summary methods.

Results

A total of 23 458 patients from 31 hospitals were included, with 14 156 patients allocated to aspirin (median [IQR] age, 69 [62-77] years; 7984 [56.4%] female) and 9302 patients allocated to enoxaparin (median [IQR] age, 70 [62-77] years; 5277 [56.7%] female). The mortality rate within 90 days of surgery was 1.67% in the aspirin group and 1.53% in the enoxaparin group (estimated difference, 0.04%; 95% CI, -0.05%-0.42%). For the subgroup of 21 148 patients with a nonfracture diagnosis, the mortality rate was 0.49% in the aspirin group and 0.41% in the enoxaparin group (estimated difference, 0.05%; 95% CI, -0.67% to 0.76%).

Conclusions and Relevance

In this secondary analysis of a cluster randomized trial comparing aspirin with enoxaparin following hip or knee arthroplasty, there was no significant between-group difference in mortality within 90 days when either drug was used for VTE prophylaxis.

Trial Registration

http://anzctr.org.au Identifier: ACTRN12618001879257.

The impact of femoral bone quality on cementless total hip pre-operative templating

INTRODUCTION

Accurate templating is an integral part of pre-operative planning for total hip arthroplasty (THA). Templating of cementless implant accuracy has been average. The aim of this study was to assess the impact of Dorr femoral classification on the accuracy of pre-operative digital templating.

PATIENTS AND METHODS

This was a retrospective study of cementless THA pre-operative planning using one implant design. A total of 210 primary THA were reviewed. A total of 102 cementless THAs matched the exclusion and inclusion criteria, using one implant combination, were analyzed by an orthopaedic resident and a fellowship trained arthroplasty surgeon. Each x-ray was evaluated and assigned a femoral Dorr classification. Accuracy of templating was determined by comparing the templated size with the actual implant size both for the femoral and acetabular components.

RESULT

Out of the 102 cases, exact templating size was achieved in 35.3% for the acetabulum, 25.5% for the femur, and only in 9.8% for both components. Reasonable templating, ± one of the actual size, was achieved in 78.4% for the acetabulum, 74.5% for the femur, and 60.8% for both components. Use of Dorr femoral type classification did not result in better templating accuracy.

CONCLUSION

Pre-operative hip cementless templating using digital x-rays with double marker method do not improve accuracy compared to other methods available for templating. Accounting for bone quality using the Dorr femoral classification did not improve accuracy.

Failure analysis of articulating polymethyl methacrylate spacers in two-stage revision total hip arthroplasty

Aims

Two-stage exchange revision total hip arthroplasty (THA) performed in case of periprosthetic joint infection (PJI) has been considered for many years as being the gold standard for the treatment of chronic infection. However, over the past decade, there have been concerns about its safety and its effectiveness. The purposes of our study were to investigate our practice, collecting the overall spacer complications, and then to analyze their risk factors.

Methods

We retrospectively included 125 patients with chronic hip PJI who underwent a staged THA revision performed between January 2013 and December 2019. All spacer complications were systematically collected, and risk factors were analyzed. Statistical evaluations were performed using the Student's t-test, Mann-Whitney U test, and Fisher's exact test.

Results

Our staged exchange practice shows poor results, which means a 42% mechanical spacer failure rate, and a 20% recurrent infection rate over the two years average follow-up period. Moreover, we found a high rate of spacer dislocation (23%) and a low rate of spacer fracture (8%) compared to the previous literature. Our findings stress that the majority of spacer complications and failures is reflecting a population with high comorbid burden, highlighted by the American Society of Anesthesiology grade, Charlson Comorbidity Index, and Lee score associations, as well as the cardiac, pulmonary, kidney, or hepatic chronic conditions.

Conclusion

Our experience of a two-stage hip exchange revision noted important complication rates associated with high failure rates of polymethylmethacrylate spacers. These findings must be interpreted in the light of the patient’s comorbidity profiles, as the elective population for staged exchange has an increasing comorbid burden leading to poor results. In order to provide better results for this specific population, our conclusion suggests that comparative strategy studies are required to improve our therapeutic indication.

Cite this article: Bone Jt Open 2022;3(6):485–494.

Extended trochanteric osteotomy: improving the access and reducing the risk in revision THA

This review article presents a comprehensive literature review regarding extended trochanteric osteotomy (ETO).

The history, rationale, biomechanical considerations as well as indications are discussed.

The outcomes and complications as reported in the literature are presented, discussed and compared with our own practice.

Based on the available evidence, we present our preferred technique for performing ETO, its fixation, as well as post-operative rehabilitation.

The ETO aids implant removal and enhanced access. Reported union rate of ETO is high. The complications related to ETO are much less frequent than in cases when accidental intra-operative femoral fracture occurred that required fixation.

Based on the literature and our own experience we recommend ETO as a useful adjunct in the arsenal of the revision hip specialist.

Cite this article: EFORT Open Rev 2020;5:104-112. DOI: 10.1302/2058-5241.5.190005

ASA class is associated with early revision and reoperation after total hip arthroplasty: an analysis of the Geneva and Swedish Hip Arthroplasty Registries

Background and purpose - Data from several joint replacement registries suggest that the rate of early revision surgery after primary total hip arthroplasty (THA) is increasing. The ASA class, now widely recorded in arthroplasty registries, may predict early revision. We investigated the influence of ASA class on the risk of revision and other reoperation within 3 months and within 5 years of primary THA. Patients and methods - We used data from the Geneva and Swedish Hip Arthroplasty Registries, on primary elective THAs performed in 1996-2016 and 2008-2016, respectively. 5,319 and 122,241 THAs were included, respectively. Outcomes were all-cause revision and other reoperations evaluated using Kaplan-Meier survival and Cox regression analyses. Results - Within 3 months after surgery, higher ASA class was associated with greater risk of revision and other reoperation. 3-month cumulative incidences of revision by ASA class I, II, and III-IV respectively, were 0.6%, 0.7%, and 2.3% in Geneva and 0.5%, 0.8%, and 1.6% in Sweden. 3-month cumulative incidences of other reoperation were 0.4%, 0.7%, and 0.9% in Geneva and 0.2%, 0.4%, and 0.7% in Sweden. Adjusted hazard ratios (ASA III-IV vs. I) for revision within 3 months were 2.7 (95% CI 1.2-5.9) in Geneva and 3.3 (CI 2.6-4.0) in Sweden. Interpretation - Assessment of ASA class of patients prior to THA will facilitate risk stratification. Targeted risk-reduction strategies may be appropriate during the very early postoperative period for patients identified as at higher risk. Systematically recording ASA class in arthroplasty registries will permit risk adjustment and facilitate comparison of revision rates internationally.

Registry stakeholders

Clinical registries are health information systems, which have the mission to collect multidimensional real-world data over the long term, and to generate relevant information and actionable knowledge to address current serious healthcare problems.

This article provides an overview of clinical registries and their relevant stakeholders, focussing on registry structure and functioning, each stakeholder’s specific interests, and on their involvement in the registry’s information input and output.

Stakeholders of clinical registries include the patients, healthcare providers (professionals and facilities), financiers (government, insurance companies), public health and regulatory agencies, industry, the research community and the media.

The article discusses (1) challenges in stakeholder interaction and how to strengthen the central role of the patient, (2) the importance of adding cost reporting to enable informed value choices, and (3) the need for proof of clinical and public health utility of registries.

In its best form, a registry is a mission-driven, independent stakeholder–registry team collaboration that enables rapid, transparent and open-access knowledge generation and dissemination.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180077

Association between patient survival following reoperation after total hip replacement and the reason for reoperation: an analysis of 9,926 patients in the Swedish Hip Arthroplasty Register

Background and purpose - The association between long-term patient survival and elective primary total hip replacement (THR) has been described extensively. The long-term survival following reoperation of THR is less well understood. We investigated the relative survival of patients undergoing reoperation following elective THR and explored an association between the indication for the reoperation and relative survival. Patients and methods - In this observational cohort study we selected the patients who received an elective primary THR and subsequent reoperations during 1999-2017 as recorded in the Swedish Hip Arthroplasty Register. The selected cohort was followed until the end of the study period, censoring or death. The indications for 1st- and eventual 2nd-time reoperations were analyzed and the relative survival ratio of the observed survival and the expected survival was determined. Results - There were 9,926 1st-time reoperations and of these 2,558 underwent further reoperations. At 5 years after the latest reoperation, relative survival following 1st-time reoperations was 0.94% (95% CI 0.93-0.96) and 0.90% (CI 0.87-0.92) following 2nd-time reoperations. At 5 years patients with a 1st-time reoperation for aseptic loosening had higher survival than expected; however, reoperations performed for periprosthetic fracture, dislocation, and infection had lower survival. Interpretation - The relative survival following 1st- and 2nd-time reoperations in elective THR patients differs by reason for reoperation. The impact of reoperation on life expectancy is more obvious for infection/dislocation and periprosthetic fracture.

Impact of hip arthroplasty registers on orthopaedic practice and perspectives for the future

Total hip arthroplasty (THA) registers are established in several countries to collect data aiming to improve the results after THA. Monitoring of adverse outcomes after THA has focused mainly on revision surgery, but patient-reported outcomes have also been investigated.Several surgery-related factors influencing the survival of the THA have been thoroughly investigated and have changed clinical practice. These factors include surgical approach, specific implants, the size of the components, type of fixation and different bone cements.Register data have been used to examine the risk of venous thromboembolism and bleeding after THA. These investigations have resulted in shorter duration of thromboprophylaxis and a reduced frequency of blood transfusion.Registers may provide specific information to surgeons on the outcome of all THAs that they have performed with a detailed analysis of revisions rates and reasons for the revisions.A number of other stakeholders can use register data to provide benchmarks. The National Joint Registry for England, Wales, Northern Ireland and the Isle of Man supplies data to the Orthopaedic Device Evaluation Panel (ODEP), which provides benchmarks at 3, 5, 7, 10, and 13 years graded from A*, A, B and C.Future perspectives: National registers have to play a major role in documenting the quality of THA in order to describe best practice and report implant outliers. The registers have to be used for research and post-market surveillance and register data may be a source for intelligent decision tools. Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180091.

Risk of further surgery on the same or opposite side and mortality after primary total hip arthroplasty: A multi-state analysis of 133,654 patients from the Swedish Hip Arthroplasty Register

Background and purpose - The hip-related timeline of patients following a total hip arthroplasty (THA) can vary. Ideally patients will live their life without need for further surgery; however, some will undergo replacement on the contralateral hip and/or reoperations. We analyzed the probability of mortality and further hip-related surgery on the same or contralateral hip. Patients and methods - We performed a multi-state survival analysis on a prospectively followed cohort of 133,654 Swedish patients undergoing an elective THA between 1999 and 2012. The study used longitudinally collected information from the Swedish Hip Arthroplasty Register and administrative databases. The analysis considered the patients' sex, age, prosthesis type, surgical approach, diagnosis, comorbidities, education, and civil status. Results - During the study period patients were twice as likely to have their contralateral hip replaced than to die. However, with passing time, probabilities converged and for a patient who only had 1 non-revised THA at 10 years, there was an equal chance of receiving a second THA and dying (24%). It was 8 times more likely that the second hip would become operated with a primary THA than that the first hip would be revised. Multivariable regression analysis reinforced the influence of age at operation, sex, diagnosis, comorbidity, and socioeconomic status influencing state transition. Interpretation - Multi-state analysis can provide a comprehensive model of further states and transition probabilities after an elective THA. Information regarding the lifetime risk for bilateral surgery, revision, and death can be of value when discussing the future possible outcomes with patients, in healthcare planning, and for the healthcare economy.