Arthroplasty implant registries over the past five decades: Development, current, and future impact

A practical guide to the development and deployment of deep learning models for the orthopaedic surgeon: Part III, focus on registry creation, diagnosis, and data privacy

Deep learning is a subset of artificial intelligence (AI) with enormous potential to transform orthopaedic surgery. As has already become evident with the deployment of Large Language Models (LLMs) like ChatGPT (OpenAI Inc.), deep learning can rapidly enter clinical and surgical practices. As such, it is imperative that orthopaedic surgeons acquire a deeper understanding of the technical terminology, capabilities and limitations associated with deep learning models. The focus of this series thus far has been providing surgeons with an overview of the steps needed to implement a deep learning-based pipeline, emphasizing some of the important technical details for surgeons to understand as they encounter, evaluate or lead deep learning projects. However, this series would be remiss without providing practical examples of how deep learning models have begun to be deployed and highlighting the areas where the authors feel deep learning may have the most profound potential. While computer vision applications of deep learning were the focus of Parts I and II, due to the enormous impact that natural language processing (NLP) has had in recent months, NLP-based deep learning models are also discussed in this final part of the series. In this review, three applications that the authors believe can be impacted the most by deep learning but with which many surgeons may not be familiar are discussed: (1) registry construction, (2) diagnostic AI and (3) data privacy. Deep learning-based registry construction will be essential for the development of more impactful clinical applications, with diagnostic AI being one of those applications likely to augment clinical decision-making in the near future. As the applications of deep learning continue to grow, the protection of patient information will become increasingly essential; as such, applications of deep learning to enhance data privacy are likely to become more important than ever before. Level of Evidence: Level IV.

Microsporidia (Encephalitozoon cuniculi) in Patients with Degenerative Hip and Knee Disease, Czech Republic

Total joint arthroplasty is a commonly used surgical procedure in orthopedics. Revision surgeries are required in >10% of patients mainly because of prosthetic joint infection caused by bacteria or aseptic implant loosening caused by chronic inflammation. Encephalitozoon cuniculi is a microsporidium, an obligate intracellular parasite, capable of exploiting migrating proinflammatory immune cells for dissemination within the host. We used molecular detection methods to evaluate the incidence of E. cuniculi among patients who had total hip or knee arthroplasty revision. Out of 49 patients, E. cuniculi genotypes I, II, or III were confirmed in joint samples from 3 men and 2 women who had implant loosening. Understanding the risks associated with the presence of microsporidia in periprosthetic joint infections is essential for proper management of arthroplasty. Furthermore, E. cuniculi should be considered a potential contributing cause of joint inflammation and arthrosis.

Thumb Arthroplasty as Reliable Long-term Solution for Trapeziometacarpal Osteoarthritis: A Minimum of 15 Years of Follow-up

BACKGROUND

In patients with symptomatic trapeziometacarpal (TMC) joint arthritis resistant to conservative treatment, surgical treatment can be advised. One of the many surgical treatment options is TMC arthroplasty. The Arpe prosthesis is one example of these TMC arthroplasties.

METHODS

This retrospective study evaluated patients who underwent TMC arthroplasty with the Arpe prosthesis after a minimum of 15 years of follow-up. Clinical, radiologic, and qualitative outcomes were assessed for 43 Arpe arthroplasties in 41 patients, of whom 2 had bilateral arthroplasties. The female to male ratio was 39:4. The mean follow-up time was 197 months (range = 180-225).

RESULTS

The cumulative survival rate after a mean of 16.5 years was 84%. Seven failures (16%) were registered, of which 5 during the first 3 years after primary surgery. All patients were successfully converted to a trapeziectomy. Quick Disabilities of the Arm, Shoulder and Hand score improved with 44.9 points and visual analogue pain score with 97% and 91% at rest and during exercise, respectively.

CONCLUSIONS

This series demonstrates that thumb arthroplasty is a reliable long-term solution for thumb base arthritis, with significant pain reduction and functional improvement, even after 15 years of follow-up.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

A Systematic Review of Data Collection by National Joint Replacement Registries: What Opportunities Exist for Enhanced Data Collection and Analysis?

BACKGROUND

National joint replacement registries assist surgeons and hospitals with guiding decision making and quality of care. The data points collected are essential to interpret and analyze data and to understand confounding variables and other sources of bias, which can impair retrospective observational research. The aim of this study was to review all national joint replacement registries to assess what data points are recorded, and in what manner, for primary and revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) so that improvements can be made to enhance data collection, interpretation, and analysis.

METHODS

All national registries were identified through Internet and publication search and contacted to invite participation. Data collection forms for both primary and revision THA and TKA were requested. Data collected were entered into an Excel spreadsheet.

RESULTS

The study group for primary and revision THA consisted of 28 national registries, with 26 agreeing to participate. The study group for primary TKA consisted of 27 national registries, with 24 agreeing to participate. Patient identification details were recorded uniformly. Only a minority recorded patient details beyond American Society of Anesthesiologists and body mass index. Most registries did not record surgeon variables: who actually performed or assisted the procedure and their level of training. There was variation in the degree of detail recorded for diagnosis, mostly regarding secondary causes of osteoarthritis and fracture. The details regarding case complexity were limited. Half recorded previous operations, and fewer recorded bone defects. The location of knee arthritis, preoperative limb alignment, and deformities were rarely recorded. Surgical approach and technological adjuncts were routinely collected, but few other details on the surgical technique were recorded. Implant details and fixation were uniformly collected, although a minority recorded specific details, including cement antibiotic or cementing technique. It was uncommon to record whether additional or adjunctive procedures were concurrently performed. Approximately half the registries lacked a revision specific form. The majority recorded reoperations in addition to revision procedures. Patient, surgeon, case, and postoperative details were recorded similar to primary procedures. There was variation in the degree of details recorded for the reasons underlying the revision +/- reoperation, with most recording greater detail for infection and fracture. Many included details on case complexity and bone defects, including the severity, classification, and how the defect was managed. The majority recorded the specific revision procedure that was performed (total or partial), the fixation used, and the components removed or revised. Other specific aspects of fixation including acetabular screws, cone or sleeve use, stems, and augments were less commonly recorded.

CONCLUSION

Substantial data are recorded by all registries, although each one is different. Data solicited lack many patient factors, surgeon variables, case complexity, and surgical techniques. Separate revision forms are not universal, and many registries do not record reoperation procedures, specific causes of revision, and the revision construct.

LEVEL OF EVIDENCE

Level II, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

National spine surgery registries' characteristics and aims: globally accepted standards have yet to be met. Results of a scoping review and a complementary survey

BACKGROUND

Surgery involving implantable devices is widely used to solve several health issues. National registries are essential tools for implantable device surveillance and vigilance. In 2017, the European Union encouraged Member States to establish "registries and databanks for specific types of devices" to evaluate device safety and performance and ensure their traceability. Spine-implantable devices significantly impact patient safety and public health; spine registries might help improve surgical outcomes. This study aimed to map existing national spine surgery registries and highlight their features and organisational standards to provide an essential reference for establishing other national registries.

METHODS

A scoping search was performed using the Embase, PubMed/Medline, Scopus, and Web of Science databases for the terms "registry", "register", "implantable", and all terms and synonyms related to spinal diseases and national registries in publications from January 2000 to December 2020. This search was later updated and finalised through a web search and an ad hoc survey to collect further detailed information.

RESULTS

Sixty-two peer-reviewed articles were included, which were related to seven national spine registries, six of which were currently active. Three additional active national registries were found through the web search. The nine selected national registries were set up between 1998 and 2021. They collect data on the procedure and use patient-reported outcome measures (PROMs) for the follow-up.

CONCLUSION

Our study identified nine currently active national spine surgery registries. However, globally accepted standards for developing a national registry of spine surgery are yet to be established. Therefore, an international effort to increase result comparability across registries is highly advisable. We hope the recent initiative from the Orthopaedic Data Evaluation Panel (ODEP) to establish an international collaboration will meet these needs.

A Comprehensive Research on the Prevalence and Evolution Trend of Orthopedic Surgeries in Romania

Accurate knowledge of the prevalence and trends of orthopedic surgeries can facilitate the design of medical plans for effective treatments. The National Endoprosthetic Registry (NER) in Romania provides statistics on endoprosthetic activity (hip, knee), cases of fractures and bone tumors as a result of the legal obligations to report interventions performed by all orthopedic traumatology hospitals/wards in the country. The aim of this study is to describe the annual volumes of orthopedic surgeries between 2001 and 2022 in Romania and analyze the current and future evolution trends of the studied surgeries, gender differences and regional differences based on a complete survey carried out at a national level. For the period 2001-2022, we extracted from the NER the annual volumes of orthopedic interventions performed. With these data, we studied the prevalence and estimated, with the support of an original calculation methodology, the variation trends of orthopedic surgeries in two situations: over the entire 21-year period, respectively, and over the period 2001-2020, which does not include the pandemic period. For hip replacement surgery and knee replacement surgery, we showed the prevalence by subcategory of interventions, gender distribution, regional prevalence and regional density calculated by the annual averages of the total number of cases reported per 100,000 people in the 40 counties of the country and the capital, Bucharest. We also determined the variations in hip and knee arthroplasty revision burdens, calculated as a percentage between the number of revisions and the number of primary interventions in the same period. We determined the regional densities of revision burdens. The total number of orthopedic surgeries in the period 2001-2022 was 1,557,247, of which 189,881 were hip replacement surgeries; 51,035 were knee replacement surgeries; 11,085 were revision hip arthroplasty; 1497 were revision knee arthroplasty; 541,440 were operated fractures; and 16,418 were operated bone tumors. The growth rates of surgical interventions are hip replacement surgery, +8.19%; knee replacement surgery, +19.55%; revision hip arthroplasty, +9.43%; and revision knee arthroplasty, +28.57%. With these data, we have estimated a doubling of the volume of primary and revision interventions of the hip until 2034 and the knee until 2027, respectively. Operated bone tumors register an annual decrease of -4.52% thanks to modern treatments. There are clear gender differences; for primary hip interventions, the proportion of women is 58.82%, and for knee interventions, the proportion of women is 76.42%. This is the first research that, with the support of exhaustive data from the NER, analyzes for the period 2001-2022 the annual number of orthopedic surgeries in Romania. It allows knowledge of the large, anticipated increases in orthopedic surgery and provides a quantitative basis for future policy decisions related to the need for medical personnel and material resources.

The value of national arthroplasty registry data in 2023

The importance of registries has been brought into focus by recent UK national reports focusing on implant (Cumberlege) and surgeon (Paterson) performance. National arthroplasty registries provide real-time, real-world information about implant, hospital, and surgeon performance and allow case identification in the event of product recall or adverse surgical outcomes. They are a valuable resource for research and service improvement given the volume of data recorded and the longitunidal nature of data collection. This review discusses the current value of registry data as it relates to both clinical practice and research.

Outcomes and risk factors for failure after débridement, antibiotics, and implant retention for elbow periprosthetic joint infection

BACKGROUND

Evidence for the management of periprosthetic joint infection (PJI) after total elbow arthroplasty is sparse, particularly in regard to débridement, antibiotics, and implant retention (DAIR). This study explored the outcomes of DAIR and analyzed risk factors for failure.

METHODS

A retrospective cohort study of patients 18 years or older diagnosed with elbow PJI and managed with DAIR between January 1, 2003, and December 31, 2018, at a single institution was performed. Twenty-six elbows met the inclusion criteria during the study period. All DAIR procedures included in this study represented an attempt to manage an acute PJI with surgical irrigation and débridement without removal of the elbow arthroplasty components, followed by long-term systemic antimicrobial therapy. DAIR failure was defined as recurrence of PJI, unplanned re-operation for infection, or death secondary to infection. A Cox proportional hazards model was used to identify possible risk factors for failure.

RESULTS

DAIR failed in 17 cases of elbow PJI with a failure rate of 65% at 2 years (95% confidence interval: 41.3%-79.6%). The median time to failure from DAIR was 43 days (interquartile range: 27-114). We found that DAIR failed in all cases with sinus tracts or negative cultures. The group with favorable outcomes had a shorter median duration of symptoms (5 vs. 18 days, P = .65) and a higher proportion of monomicrobial infections (58.8% vs. 88.9%, P = .19) compared to those with unfavorable outcomes. However, with the numbers available, none of the possible risk factors analyzed for association with failure reached statistical significance.

CONCLUSION

DAIR for elbow PJI was associated with high rates of failure. Possible risk factors for failure may include the presence of sinus tract, longer duration of symptoms, and culture-negative infection. Although the relatively low morbidity of DAIR compared with total elbow arthroplasty implant resection for a one-stage or two-stage reimplantation is attractive, patients considered for DAIR must know that the chance of success is limited to approximately 35%.

Does Metabolic Syndrome Impact the Risk of Reoperation, Revision, or Complication After Primary Total Knee Arthroplasty?

BACKGROUND

Metabolic syndrome (MetS) is an increasingly frequent condition characterized by insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study evaluated implant survivorship, complications, and clinical outcomes of primary TKAs performed in patients who have MetS.

METHODS

Utilizing our institutional total joint registry, 2,063 primary TKAs were performed in patients with a diagnosis of MetS according to the World Health Organization criteria. MetS patients were matched 1:1 based on age, sex, and surgical year to those who did not have the condition. The World Health Organization's body mass index (BMI) classification was utilized to evaluate the effect of obesity within MetS patients. Kaplan-Meier methods were utilized to determine implant survivorship. Clinical outcomes were assessed with Knee Society scores. The mean follow-up was 5 years.

RESULTS

MetS and non-MetS patients did not have significant differences in 5-year implant survivorship free from any reoperation (P = .7), any revision (P = .2), and reoperation for periprosthetic joint infection (PJI; P = .2). When stratifying, patients with MetS and BMI >40 had significantly decreased 5-year survivorship free from any revision (95 versus 98%, respectively; hazard ratio = 2.1, P = .005) and reoperation for PJI (97 versus 99%, respectively; hazard ratio = 2.2, P = .02). Both MetS and non-MetS groups experienced significant improvements in Knee Society Scores (77 versus 78, respectively; P < .001) that were not significantly different (P = .3).

CONCLUSION

MetS did not significantly increase the risk of any reoperation after TKA; however, MetS patients with BMI >40 had a two-fold risk of any revision and reoperation for PJI. These results suggest that obesity is an important condition within MetS criteria and remains an independent risk factor.

LEVEL OF EVIDENCE

Level 3, Case-control study.

Innovative technologies for reverse total shoulder arthroplasty in Australia: Market access challenges and implications for patients, decision-makers, and manufacturers

PURPOSE

The success of reverse total shoulder arthroplasty (RTSA) has expanded its use for a broader range of shoulder indications worldwide. Evidence regarding the relative efficacy and long-term safety of medical technologies used in RTSA is subjected to rigorous assessment. Nonetheless, substantial challenges impede market access for innovative shoulder implant technologies for RTSA in Australia, resulting in delayed patient access.

APPROACH

This paper addresses the key challenges associated with generating evidence for the health technology assessments of innovative medical technologies for RTSA that are required for access to the Australian market. The transition to value-based care requires establishing a benchmarking reference that incorporates patient-reported outcome measures (PROMs) and combines revision outcomes with additional clinical outcomes to increase patient cohort sizes. Establishing the benchmark would require agreement on the outcome measures to be collected for each indication, and investment in reporting patient-reported outcomes for RTSA to the national orthopaedic registry.

IMPLICATIONS FOR PRACTICE

The need for increased flexibility in developing evidence for health technology assessment of RTSA medical technologies is required. Optimised approaches for benchmarking RTSA require extensive stakeholder discussions, including the agreement on evidence requirements and follow-up periods, selection of clinical outcomes, as well as pre-operative and post-operative PROMs as a value assessment.

Revision total knee arthroplasty for flexion instability : a concise follow-up of a previous report

AIMS

We have previously reported the mid-term outcomes of revision total knee arthroplasty (TKA) for flexion instability. At a mean of four years, there were no re-revisions for instability. The aim of this study was to report the implant survivorship and clinical and radiological outcomes of the same cohort of of patients at a mean follow-up of ten years.

METHODS

The original publication included 60 revision TKAs in 60 patients which were undertaken between 2000 and 2010. The mean age of the patients at the time of revision TKA was 65 years, and 33 (55%) were female. Since that time, 21 patients died, leaving 39 patients (65%) available for analysis. The cumulative incidence of any re-revision with death as a competing risk was calculated. Knee Society Scores (KSSs) were also recorded, and updated radiographs were reviewed.

RESULTS

The cumulative incidence of any re-revision was 13% at a mean of ten years. At the most recent-follow-up, eight TKAs had been re-revised: three for recurrent flexion instability (two fully revised to varus-valgus constrained implants (VVCs), and one posterior-stabilized (PS) implant converted to VVC, one for global instability (PS to VVC), two for aseptic loosening of the femoral component, and two for periprosthetic joint infection). The ten-year cumulative incidence of any re-revision for instability was 7%. The median KSS improved significantly from 45 (interquartile range (IQR) 40 to 50) preoperatively to 70 (IQR 45 to 80) at a mean follow-up of ten years (p = 0.031). Radiologically, two patients, who had not undergone revision, had evidence of loosening (one tibial and one patellar). The remaining components were well fixed.

CONCLUSION

We found fair functional outcomes and implant survivorship at a mean of ten years after revision TKA for flexion instability with a PS implant. Recurrent instability and aseptic loosening were the most common indications for re-revision. Components with increased constraint, such as a VVC or hinged, should be used in these patients in order to reduce the risk of recurrent instability.Cite this article: Bone Joint J 2022;104-B(10):1126-1131.

The Influence of Surgeon Sex on Adverse Events Following Primary Total Hip Arthroplasty: A Register-Based Study of 11,993 Procedures and 200 Surgeons in Swedish Public Hospitals

BACKGROUND

Stereotypes may prevail, but little is known about the influence that the sex of an orthopaedic surgeon may have on outcomes. In a recently published study, there were no differences in the rate of adverse events following total hip arthroplasties (THAs) performed by female or male orthopaedic surgeons. The objective of the present study was to investigate whether there was any difference in adverse events within 90 days following a primary THA performed by either a male or female surgeon in Sweden.

METHODS

A retrospective study was performed to evaluate primary THAs performed for osteoarthritis between 2008 and 2016 at 10 hospitals in western Sweden. Local hospital data were linked with the Swedish Hip Arthroplasty Register (SHAR) and with a regional patient register. Data collected from local hospitals and the SHAR included surgeon-related information (e.g., sex, annual volume, and level of training) and patient-related information (e.g., age, sex, and Elixhauser comorbidity index). Adverse events were retrieved from the regional patient register. The definition of adverse events followed the SHAR definition of adverse events. Mixed models were used to investigate the impact of surgeon sex on adverse events.

RESULTS

A total of 11,993 primary THAs were performed by 200 surgeons, of whom 17.5% were women. The proportions of adverse events within 90 days were similar for female (6%) and male (7%) surgeons. No association was found between surgeon sex and adverse events (adjusted odds ratio, 0.72; 95% confidence interval, 0.52 to 1.00) when all surgeons (both attendings and residents) were included in the analysis. A sensitivity analysis that included attendings only yielded similar results (adjusted odds ratio, 0.88; 95% confidence interval, 0.60 to 1.29).

CONCLUSIONS

Despite a small tendency toward lower rates of adverse events at 90 days after THAs performed by female surgeons, there was no significant association between surgeon sex and the risk of adverse events following THA.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Surgical therapy in osteoarthritis

OBJECTIVE

To provide an evidence-based overview of the different surgical procedures in osteoarthritis (OA).

DESIGN

This narrative review reports on surgical therapies (1) for severe, end stage OA and (2) of surgical options aiming to possibly reduce OA development earlier in the course of the disease.

RESULTS

Surgical practice guidelines provide evidence-based recommendations to assist in the clinical decision-making. Total joint arthroplasty represents the only valuable, established surgical option for severe, end stage OA. For hip and knee OA, it is by far the most common surgical procedure and provides considerable pain relief, functional restoration, and improved quality of life. Surgical therapy aiming to postpone OA essentially addresses extra- or intraarticular pre-osteoarthritic deformities, defined as congenital or acquired disturbances of the joint structure that adversely affect its function. Approaches in this category include osteotomies and different cartilage repair procedures such as osteochondral autograft and allograft transfer, marrow stimulation techniques, and autologous chondrocyte implantation. However, they are not only less commonly performed than arthroplasty, but the scientific clinical evidence in favour of this type of surgery to reduce the long-term risk of developing OA is considerably reduced.

CONCLUSION

Total knee and hip arthroplasty are two of the most successful procedures in all of medicine. As the progression of this insidious disease is often asymptomatic and slow, it is imperative to judge reparative procedures at their potential to reduce OA development at long-term, besides their primary clinical outcomes. Evidence-based guidelines provide a valuable tool for high-quality surgical decision making in OA.

Truth in DAIR: Duration of Therapy and the Use of Quinolone/Rifampin-Based Regimens following Debridement and Implant Retention for Periprosthetic Joint Infections

Background

The optimal duration of antibiotic therapy after debridement and implant retention (DAIR) for periprosthetic joint infections (PJIs) is debated. Furthermore, the best antibiotic regimens for staphylococcal PJI are also unclear. In this study, we evaluated the impact of antibiotic therapy duration on the risk of failure. We assessed the utility of rifampin-based regimens for staphylococcal PJI managed with DAIR.

Methods

We performed a retrospective cohort study of patients 18 years and older diagnosed with hip and knee PJI who underwent DAIR between January 1, 2008 and 31 December 31, 2018 at Mayo Clinic, USA. The outcome was failure of DAIR. For statistical analysis, joint-stratified Cox regression models adjusted for age, sinus tract, symptom duration, and primary/revision arthroplasty were performed.

Results

We examined 247 cases of PJI with a median follow-up of 4.4 years (interquartile range [IQR], 2.3–7) after DAIR. The estimated 5-year cumulative incidence of failure was 28.1% (n = 65). There was no association between the duration of intravenous (IV) antibiotics (median 42 days; IQR, 38–42) and treatment failure (P = .119). A shorter duration of subsequent oral antibiotic therapy was associated with a higher risk of failure (P = .005; eg, 90-day vs 1-year duration; hazard ratio [HR], 3.50; 95% confidence interval [CI], 1.48–8.25). For staphylococcal knee PJI, both the use and longer duration of a rifampin-based regimen were associated with a lower risk of failure (both P = .025). There was no significant association between fluoroquinolone (FQ) use and failure (HR, 0.62; 95% CI, .31–1.24; P = .172).

Conclusions

The duration of initial IV antibiotic therapy did not correlate with treatment failure in this cohort of patients. Rifampin use is recommended for staphylococcal knee PJI. There was no apparent benefit of FQ use in staphylococcal PJI.

Disability, Health-Related Quality of Life and Mortality in Lumbar Spine Fusion Patients-A 5-Year Follow-Up and Comparison With a Population Sample

STUDY DESIGN

Prospective follow-up study.

OBJECTIVES

We aimed to assess the effect of lumbar spine fusion (LSF) on disability, health-related quality of life and mortality in a 5-year follow-up, and to compare these results with the general population.

METHODS

523 consecutive LSF operations were included in a prospective follow-up. Disability was assessed by the Oswestry Disability Index (ODI), and HRQoL by the 36-item Short Form (SF-36) questionnaire using the physical and mental summary scores (PCS and MCS). The patients were compared with an age-, sex-, and residential area matched general population cohort.

RESULTS

The preoperative ODI in the patients was 46 (SD 16), and the change at 5 years was -26 (95% CI: -24 to -28), p < 0.001. In the population, ODI (baseline 13, SD 16) remained unchanged. The preoperative PCS in the patients was 27 (SD 7), in the population 45 (SD 11), and the increase in the patients at 5 years was 8 (95% CI: 7 to 9), p < 0.001. The patients did not reach the population in ODI or PCS. The baseline MCS in the patients was 47 (SD 13), and the change at 5 years 4 (95% CI: 3 to 7), p < 0.001. MCS of the females reached the population at 5-year follow-up. When analyzing short and long fusions separately, comparable changes were seen in both subgroups. There was no difference in mortality between the patients (3.4%) and the population (4.8%), hazard ratio (HR) 0.86.

CONCLUSIONS

Although the patients who had undergone LSF benefited from surgery still at 5 years, they never reached the physical level of the population.

Computer-Assisted Surgery Enables Beginner Surgeons, Under Expert Guidance, to Achieve Long-Term Clinical Results not Inferior to Those of a Skilled Surgeon in Knee Arthroplasty

PURPOSE

The purpose of this study is to determine whether the use of a surgical navigation system in total knee replacement (TKR) enables beginner and intermediate surgeons to achieve clinical PROM outcomes as good as those conducted by expert surgeons in the long term.

METHODS

We enrolled 100 consecutive patients whose total navigated knee arthroplasty (TKA) was performed in our institution from 2008 to 2010. According to the principal surgeon's surgical experience, the patients were divided into three groups: (1) beginner surgeons, with no more than 30 previous knee replacement performances, (2) intermediate surgeons, with more than 30 but not more than 300, and (3) expert surgeons, with more than 300 knee replacements. Demographic data collected on the cohort included gender, laterality, age, and body mass index (BMI). The outcome measures assessed were Forgotten Joint Score (FJS), implant positioning, limb alignment, and prosthesis survival rate. A margin of equivalence of ± 18.5 points in the FJS scale was prespecified in terms of the minimal clinically important difference (MCID) to compare the FJS results obtained in the long period between the groups of interest.

RESULTS

The mean follow-up was 11.10 ± 0.78, 10.86 ± 0.66, and 11.30 ± 0.74 years, respectively, for each of the groups. The long-term FJS mean score was 80.86 ± 21.88, 81.36 ± 23.87, and 90.48 ± 14.65 for each group. The statistical analysis proved noninferiority and equivalence in terms of the FJS results reported in the long term by patients in Groups 1 or 2 compared to those in Group 3. More specifically, it has been proved that the mean difference between groups is within the interval of equivalence defined in terms of the MCID. The overall prostheses survival rate was 93.7%.

CONCLUSION

Navigated assisted TKA, under expert guidance, can be as effective when performed by beginner or intermediate surgeons as performed by senior surgeons regarding the accuracy of implant positioning, limb alignment, and long-term clinical outcome.

The Legal, Ethical, and Scientific Considerations for Returning Explanted Orthopaedic Hardware to the Patient

Orthopaedic hardware explantation is a multifaceted topic with complex legal, ethical, and scientific aspects that require thorough exploration. Issues of device ownership, explant-induced disease propagation, and potential device resale pose legal risks to providers and health-care institutions. Ethically, implant removal highlights the potential that performing procedures at the request of the patient will incentivize patient compliance and strengthen the patient-surgeon relationship. However, the return of explanted hardware to patients could hinder scientific study and innovation, ultimately limiting advancement in risk reduction and patient outcomes. Continued research into these topics remains paramount to ensure that clinicians and institutions deliver optimal patient care while abiding with legal and ethical imperatives. This article addresses the legal, ethical, and scientific issues that are pertinent to returning an explanted orthopaedic implant to the patient and the potential ramifications of such practice.

Orthopaedic surgeons' perceptions of the changing burden of revision joint replacement surgery in Australia: A qualitative study

BACKGROUND

Studies examining trends in revision joint replacement surgery have been quantitative in their design. A qualitative research approach could provide detailed insights into the changing burden of revision surgery from an important stakeholder perspective. This study aimed to investigate orthopaedic surgeons' perceptions around the burden of revision hip and knee replacement surgery in Australia.

METHODS

A descriptive qualitative study design was used. Highly experienced Australian orthopaedic surgeons specialising in primary and/or revision hip and knee replacement surgery were purposely sampled. Interviews covered the perceived burden of revision joint replacement, factors contributing to revision burden and anticipated future burden. Deductive and inductive coding techniques were used to identify themes.

RESULTS

Semi-structured interviews were conducted with 14 orthopaedic surgeons, who had substantial consultant experience (range 15-30 years) and largely high-volume practices. Five key themes were identified: (1) Revision burden has decreased over time; (2) Changes in clinical indications; (3) Perceived lack of policies focused on minimising revision surgery; (4) Role of the national registry and (5) Future trends and opportunities.

CONCLUSION

The main indications for revision joint replacement surgery were perceived to have changed over time, moving away from implant failure-related causes towards infection and periprosthetic fracture. Most participants considered that formal policies designed to reduce revision rates did not exist but acknowledged the positive role of the national registry, particularly within an international context. The improving evidence base and provision of registry feedback on surgeon and implant performance was expected to reduce the proportion of revision procedures.

Microbiology of hip and knee periprosthetic joint infections: a database study

OBJECTIVES

Knowledge of the microbiological aetiology of periprosthetic joint infection (PJI) is essential to its management. Contemporary literature from the United States on this topic is lacking. This study aimed to identify the most common microorganisms associated with types of arthroplasty, the timing of infection, and clues to polymicrobial infection.

METHODS

We performed an analytical cross-sectional study of patients 18 years of age or older with hip or knee PJI diagnosed at our institution between 2010 and 2019. PJI was defined using the criteria adapted from those of the Musculoskeletal Infection Society. Cases included PJI associated with primary or revision arthroplasty and arthroplasty performed at our institution or elsewhere.

RESULTS

A total of 2067 episodes of PJI in 1651 patients were included. Monomicrobial infections represented 70% of episodes (n = 1448), with 25% being polymicrobial (n = 508) and the rest (5%, n = 111) culture-negative. The most common group causing PJI was coagulase-negative Staphylococcus species (other than S. ludgunensis) (37%, n = 761). The distribution of most common organisms was similar regardless of arthroplasty type. The S. aureus complex, Gram-negative bacteria, and anaerobic bacteria (other than Cutibacterium species) were more likely to be isolated than other organisms in the first year following index arthroplasty (OR 1.7, 95%CI 1.4-2.2; OR 1.5, 95%CI 1.1-2.0; and OR 1.5, 95%CI 1.0-2.2, respectively). The proportion of culture-negative PJIs was higher in primary than revision arthroplasty (6.5% versus 3%, p 0.0005). The presence of a sinus tract increased the probability of the isolation of more than one microorganism by almost three-fold (OR 2.6, 95%CI 2.0-3.3).

CONCLUSIONS

Joint age, presence of a sinus tract, and revision arthroplasties influenced PJI microbiology.

Is American Joint Replacement Registry Data Representative of National Data? A Comparative Analysis

INTRODUCTION

The American Academy of Orthopaedic Surgeons American Joint Replacement Registry (AJRR) is the largest registry of total hip and knee arthroplasty (THA and TKA) procedures performed in the United States. The purpose of this study was to examine whether AJRR data are representative of the national experience with hip and knee arthroplasty as represented in the National (Nationwide) Inpatient Sample (NIS).

METHODS

All patients undergoing a THA or TKA procedure between 2012 to 2018 (AJRR) and 2012 to 2016 (NIS) were identified. Cohen d effect sizes were computed to ascertain the magnitude of differences in demographics, hospital volume (in 50 patient increments), and geographic characteristics between the AJRR and NIS databases.

RESULTS

The study included (NIS: 2,316,345 versus AJRR: 557,684) primary THA and (NIS: 3,417,700 versus AJRR: 809,494) TKA procedures. The magnitude of distribution, as determined by the Cohen d effect size, showed that the proportions of AJRR and NIS patients were similar based on overall sex (THAs [d = 0.03] and TKAs [d = 0.02]) and age (THAs [d = 0.17] and TKAs [d = 0.12]). Similarly, only small differences (d = 0.34 or less) were identified between databases considering hospital volume and geography. The AJRR was underrepresented in Southern regions and hospitals with low procedure volume and overrepresented in Northern hospitals and those with larger volume. Both the NIS and the AJRR followed a similar overall trend, with most procedures performed at hospitals with <50 cases per year.

DISCUSSION

Distributions across hospital volume, age, and geography were proportionally similar between the AJRR and NIS databases, supporting the generalizability of AJRR findings to the larger US cohort.

Assessment of the Value of Registries in Shoulder Arthroplasty Using Reverse Arthroplasty as an Example

INTRODUCTION

As a consequence of the Swedish model, endoprosthesis registers have become increasingly important worldwide. Due to the increasing number of joint replacements at the shoulder, these are being increasingly included in the register databases - in addition to interventions at the hip and knee joint. In this study, the value of endoprosthesis registers is investigated, using the example of shoulder endoprosthetics and including a comparison with clinical studies.

MATERIAL AND METHODS

The annual reports of 32 different endoprosthesis registers with data on hip, knee and/or shoulder arthroplasty were analysed. The number of operations and demographic patient data for all areas of endoprosthetics were examined. In addition, a more detailed consideration of variables such as the primary diagnosis, the cause of the revision, the revision rate depending on risk factors and patient-reported outcome measures (PROM scores) was carried out exclusively for the shoulder joint endoprostheses. Using the example of the inverse shoulder prosthesis, clinical studies were compared to registry data with special regard to the revision rate.

RESULTS

A total of 20 endoprosthesis registers could be included, 9 of these collected data on shoulder arthroplasty. The main primary diagnoses were osteoarthritis (40.6%), rotator cuff defect arthropathy (30.2%) and fractures (17.6%). The most commonly used shoulder joint endoprosthesis was the inverse prosthesis (47.3%). The proportion of revision surgeries in total shoulder arthroplasty operations was less than 10% in all registers. In addition to the revision rate, the PROM scores were sometimes used in the registers to evaluate the success of the prosthesis. Compared to registry data, clinical studies showed more heterogeneous data with a significantly higher revision rate of over 10% in long-term follow-up - using the example of the inverse shoulder prosthesis.

CONCLUSION

Register data are a valuable source of information in shoulder arthroplasty and can make a significant contribution to the quality assurance of endoprosthetic treatments. Compared to clinical studies, they primarily provide data on durability of different endoprosthesis and give lower revision rates. Clinical studies use PROM scores and clinical and radiological examinations to focus only on individual implants and surgical centres on the one hand and much more on the functional results on the other.

Registries: Big data, bigger problems?

Patient registries have grown in size and number along with general computing power and digitization of the healthcare world. In contrast to databases, registries are typically patient data systematically created and collected for the express purpose of answering health-related questions. Registries can be disease-, procedure-, pathology-, or product-based in nature. Registry-based studies typically fit into Level II or III in the hierarchy of evidence-based medicine. However, a recent advent in the use of registry data has been the development and execution of registry-based trials, such as the TASTE trial, which may elevate registry-based studies into the realm of Level I evidence. Some strengths of registries include the sheer volume of data, the inclusion of a diverse set of participants, and their ability to be linked to other registries and databases. Limitations of registries include variable quality of the collected data, and a lack of active follow-up (which may underestimate rates of adverse events). As with any study type, the intended design does not automatically lead to a study of a certain quality. While no specific tool exists for assessing the quality of a registry-based study, some important considerations include ensuring the registry is appropriate for the question being asked, whether the patient population is representative, the presence of an appropriate comparison group, and the validity and generalizability of the registry in question. The future of clinical registries remains to be seen, but the incorporation of big data and machine learning algorithms will certainly play an important role.

The First Report of the International Cartilage Regeneration and Joint Preservation Society's Global Registry

OBJECTIVE

The International Cartilage Regeneration and Joint Preservation Society's (ICRS's) global registry, aims to be the best source of information for patients and an unbiased resource of evidence-based medicine for scientists and clinicians working to help those unfortunate enough to suffer the pain and disability associated with articular cartilage lesions. This article constitutes the scientific summary of the reports' main findings.

DESIGN

The article outlines the historical precedents in the development of orthopedic registries from the earliest tumor registries, then local arthroplasty databases that led ultimately to international collaborations between national arthroplasty and soft tissue registries. The ICRS global cartilage registry was designed from the outset as a GDPR (General Data Protection Regulation) compliant, multilingual, multinational cooperative system. It is a web-based user-friendly, live in 11 languages by end 2019, which can be accessed via https://cartilage.org/society/icrs-patient-registry/. Patients and clinicians enter data by smartphone, tablet, or computer on any knee cartilage regeneration and joint preservation treatment, including the use of focal arthroplasty. Knee Injury and Osteoarthritis Outcome Score and Kujala patient-reported outcome measures are collected preoperatively, 6 months, 12 months, and annually for ten years thereafter. EQ-5D data collection will allow cost-effectiveness analysis. Strengths, weaknesses, and future plans are discussed.

RESULTS

Since inception the registry has 264 users across 50 countries. Major findings are presented and discussed, while the entire first ICRS global registry report is available at https://cartilage.org/society/icrs-patient-registry/registry-annual-reports/. Conclusion. A measure of the maturity of any registry is the publication of its findings in the peer reviewed literature. With the publication of its first report, the ICRS global registry has achieved that milestone.

The rise of registry-based research: a bibliometric analysis

Background and purpose - The main purpose of arthroplasty registries is to collect information on patients, techniques, and devices to monitor and improve the outcome of the specific procedure. This study analyses the role played by registries in the orthopedic research community and describes publication trends, characteristics, and patterns of this field of research.Patients and methods - A descriptive-bibliometric review was conducted. Scopus was the database used for the research. All articles published from 1991 to December 2020 containing keywords related to registries and arthroplasty were considered. In particular, the following dimensions were analyzed in detail: (i) papers/year; (ii) journals; (iii) countries; (iv) research growth rate; (v) collaboration among countries. VOSviewer software was used to perform the bibliometric analysis. Finally, the 50 most cited papers of the last 10 years were briefly analyzed.Results - 3,933 articles were identified. There has been growing interest in the topic since 2010. Acta Orthopaedica ranked first for the number of articles published. The country with the largest number of articles citing registries was the United States, followed by the United Kingdom and Sweden. The relative number of articles per 100,000 inhabitants is 0.60 for Europe and 0.38 for the United States. The literature in this research area has an average yearly growth rate of 28%.Interpretation - The publication rate in the field of arthroplasty registries is constantly growing with a noteworthy impact in the evolution of this research and clinical area. The growth rate is significantly higher than that of arthroplasty literature (28% vs. 10%) and the collaboration among countries is strong and increasing with time.

The Fragility of Statistically Significant Findings From Randomized Controlled Trials in Hip and Knee Arthroplasty

BACKGROUND

The Fragility Index (FI) is a method for evaluating the robustness of statistically significant findings from randomized controlled trials (RCTs) beyond the P value in trials with dichotomous outcomes. The FI is defined as the number of patients in one arm of a trial that would have to have a different outcome to change the results of the trial from statistically significant to nonsignificant. This review assessed the FI in arthroplasty RCTs.

METHODS

A systematic search was conducted in MEDLINE, Embase, and Web of Science for RCTs related to primary total joint arthroplasty (TJA) from 2010 to 2020. Trials with a statistically significant dichotomous primary outcome were included. The FI was calculated using Fisher's exact test to determine how many events would need to be reversed to change a study from statistically significant to nonsignificant.

RESULTS

A total of 34 RCTs were included. The median sample size was 103 patients (range 24-791). The median FI was 1 (range 0-45), meaning that reversing the outcome of just one patient in either treatment group of each trial would change it from a significant to a nonsignificant result.

CONCLUSION

Hip and knee arthroplasty RCTs with statistically significant dichotomous outcomes in TJA are fragile. The median FI in TJA is lower than the FI in any of the other previously reported orthopedic subspecialties. Fragility is another reason to be cautious when conducting or interpreting small trials, and to continue to strive toward large trials to answer important questions in TJA.

LEVEL OF EVIDENCE

Level I.

Medico-Legal Issues Related to Hip and Knee Arthroplasty: A Literature Review Including the Indian Scenario

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are commonly performed surgeries worldwide. The number of joint replacement surgeries being performed has increased considerably over the past two decades, but it has also seen an increase in litigation associated with it. The purpose of our study was to review and consolidate literature regarding medico-legal issues pertaining to THA and TKA cases. We looked at the causes of litigation, medico legal aspects of pre-operative requirements, optimisation of medical condition, indications and contraindications for arthroplasty, informed consent, implants, mixing of components from different manufacturers and post-operative rehabilitation. We also wanted to analyse available literature and legal proceedings regarding these cases in India specifically.

Development of a multivariable prediction model for early revision of total knee arthroplasty - The effect of including patient-reported outcome measures

Background

Revision TKA is a serious adverse event with substantial consequences for the patient. As revision is becoming increasingly common in patients under 65 years, the need for improved preoperative patient selection is imminently needed. Therefore, this study aimed to identify the most important factors of early revision and to develop a prediction model of early revision including assessment of the effect of incorporating data on patient-reported outcome measures (PROMs).

Material and methods

A cohort of 538 patients undergoing primary TKA was included. Multiple logistic regression using forward selection of variables was applied to identify the best predictors of early revision and to develop a prediction model. The model was internally validated with stratified 5-fold cross-validation. This procedure was repeated without including data on PROMs to develop a model for comparison. The models were evaluated on their discriminative capacity using area under the receiver operating characteristic curve (AUC).

Results

The most important factors of early revision were age (OR 0.63 [0.42, 0.95]; P = 0.03), preoperative EQ-5D (OR 0.07 [0.01, 0.51]; P = 0.01), and number of comorbidities (OR 1.01 [0.97, 1.25]; P = 0.15). The AUCs of the models with and without PROMs were 0.65 and 0.61, respectively. The difference between the AUCs was not statistically significant (P = 0.32).

Conclusions

Although more work is needed in order to reach a clinically meaningful quality of the predictions, our results show that the inclusion of PROMs seems to improve the quality of the prediction model.

The case for an academic discipline of medical device science

Medical devices are a very important but largely under-recognized and fragmented component of healthcare.The limited regulation of the past and the lack of systematic rigorous evaluation of devices leading to numerous high-profile failures will now be replaced by stricter legal requirements and more transparent evaluation processes.This constitutes an unprecedented opportunity, but it also uncovers urgent needs in landscaping, methodology development, and independent comprehensive assessment of device risks and benefits for individual patients and society, especially in the context of increasingly complex devices.We argue that an academic discipline of 'medical device science' is well placed to lead and coordinate the efforts necessary to achieve much needed improvement in the medical device sector.Orthopaedics and traumatology could contribute and benefit considerably as one of the medical specialties with the highest use of medical devices. Cite this article: EFORT Open Rev 2021;6:160-163. DOI: 10.1302/2058-5241.6.200094.

Direct anterior approach versus posterior approach in primary total hip replacement: comparison of minimum 2-year outcomes

INTRODUCTION

The direct anterior approach (DAA) has gained popularity in recent years for total hip arthroplasty (THA). Several authors reported significantly better early outcomes when compared to the posterior approach (PA). Nevertheless, controversy exists regarding longer-term benefits of the DAA.

METHODS

Data was prospectively collected and retrospectively reviewed for primary THAs conducted between July 2008 and July 2016. Patients who underwent DAA and PA with minimum 2-year follow-up for Harris Hip Score (HHS), Forgotten Joint Score-12 (FJS-12), Veteran RAND 12 Mental (VR-12 Mental), Veteran RAND 12 Physical (VR-12 Physical), 12-Item Short Form Survey Mental (SF-12 Mental), 12-Item Short Form Survey Physical (SF-12 Physical), visual analogue scale, and patient satisfaction were included. Propensity score matching was performed on the DAA and PA cohorts (1:1) based on the following variables: age, sex, body mass index, and laterality.

RESULTS

205 DAA hips were satisfactorily matched to 205 PA hips. The DAA group had higher scores at final follow-up for VR-12 Mental (p = 0.0145), VR-12 Physical (p = 0.0236), SF-12 Mental (p = 0.0393), and SF-12 Physical (p = 0.0391). The DAA and PA groups had comparable HHS (p = 0.0737) and FJS-12 (p = 0.2900).

CONCLUSIONS

Although the DAA and PA groups had different follow-up periods, both the DAA and PA groups reported favourable outcomes at minimum 2-year follow-up. While both groups achieved comparable scores for the majority of PROs including VAS and patient satisfaction, the DAA group achieved superior quality of life outcomes when compared with a propensity score matched group of PA surgeries.

Trends in Knee and Hip Arthroplasty in Chile Between 2004 and 2019

Introduction

The purpose of this study is to describe the incidence rate (IR) per 100,000 inhabitants of arthroplasty in Chile between 2004 and 2019, emphasizing knee and hip arthroplasty.

Methods

This is a cross-sectional study. Patients who underwent arthroplasty between 2004 and 2019 were identified in the free access database of the Chilean Department of Statistics and Health Information (DEIS), which depends directly on the Ministry of Health. This register stores all hospital discharges of the country from private or public health centers. The trend during the period of study was analyzed using Spearman's correlation.

Results

From a total of 111,303 patients, 133,518 arthroplasties were performed. Hip arthroplasty (HA) accounted for 73.35%, followed by knee arthroplasty (KA) (23,92%). A significant upward trend was found in HA (rho=0.95, p<0.000) and KA (rho=0.98, p<0.000). Most of the surgeries were done within the Public Health Network (61,6%), but 20% of patients affiliated with public insurance underwent arthroplasty in a private center. Patients above 60 years of age affiliated with private insurance underwent 1.8 HA and 2.5 KA for every one HA and KA undergone by patients of the same age group who were affiliated with public insurance.

Conclusion

HA was more frequent than KA. A significant gap was found in the incidence of arthroplasty as compared to countries belonging to the Organization for Cooperation and Economic Development, given by a less aged population and by inequity in health access. Wider coverage and a national registry for arthroplasty must be considered in Chilean health policies.

Completeness and capture rate of publicly funded arthroplasty procedures in the New Zealand Joint Registry

BACKGROUND

Registry-based studies have become more common due to the availability of a large study cohort. However, the validity of findings is dependent on the completeness of the registry. This study aimed to validate the capture rate of the New Zealand Joint Registry (NZJR) by matching procedures that have been recorded separately via clinical coding by the New Zealand Government's National Surgical Site Infection Improvement Programme (SSIIP).

METHODS

The National Health Index, a unique identification code for all patients, was combined with the arthroplasty procedure performed (primary total knee arthroplasty (TKA), primary total hip arthroplasty (THA), revision TKA or revision THA) and operation side. Publicly funded procedures recorded in the NZJR were matched with procedures recorded by the SSIIP on a record-by-record basis. This identified the total number of arthroplasty procedures performed in New Zealand, which was used as the denominator value to calculate the procedure capture rate of the NZJR.

RESULTS

Between 2013 and 2018, 24 556 primary TKA, 28 970 primary THA, 2107 revision TKA and 4263 revision THA procedures were recorded by both datasets. The NZJR recorded 95.5% of primary TKA procedures, 96.3% of primary THA procedures, 97.1% of revision TKA procedures and 95.2% of revision THA procedures.

CONCLUSION

The NZJR recorded >95% of publicly funded arthroplasty procedures. In contrast, there were inaccuracies in clinical coding by hospitals, particularly with revision procedures, demonstrating the benefits of an arthroplasty registry. However, data recorded by an infection surveillance programme may supplement arthroplasty registry data to strengthen the quality of research.

A small number of surgeons outside the control-limit: an observational study based on 9,482 cases and 208 surgeons performing primary total hip arthroplasties in western Sweden

Background and purpose - Feedback programs relating to surgeon levels have been introduced in some orthopedic quality registers around the globe. The aim of an established surgeon feedback program is to help surgeons understand their practice and enable an analysis of their own results. There is no surgeon feedback program in Sweden in the orthopedic quality registers and there is a fear that a feedback system might pinpoint surgeons as poor performers, partly due to patient case mix. As a step prior to the introduction of a future possible feedback program in Sweden, we assessed the variation in the occurrence of adverse events (AE) within 90 days and reoperations within 2 years between surgeons in western Sweden and explored the number of surgeons outside the control-limit following primary total hip arthroplasties (THAs).Patients and methods - Patient data, surgical data, and information on the surgeons, relating to surgeries performed in 2011-2016, were retrieved from 9 publicly funded hospitals in western Sweden. Data from medical hospital records, the Swedish Hip Arthroplasty Register (SHAR) and a regional patient register located in western Sweden were linked to a database. Funnel plots with control-limits based on upper 95% and 99.8% confidence intervals (CI) were used to illustrate the variation between surgeons in terms of the outcome and to explore the number of surgeons outside the control-limit. Both observed and standardized proportions are explored. The definition of surgeons outside the control-limit in the study is a surgeon above the upper 95% CI.Results - The study comprised 9,482 primary THAs due to osteoarthritis performed by 208 surgeons, where 91% of the included primary THAs were performed by orthopedic specialists and 9% by trainees. The mean overall annual volume for all surgeons was 27. The observed overall mean rate for AEs within 90 days for all surgeons was 6.2% (5.8-6.7) and for reoperations within 2 years 1.8% (1.7-2.2). The proportion of surgeons outside the 95% CI was low for both AEs (0-5%) and reoperations within 2 years (0-1%) in 2011-2016. The corresponding numbers were even lower for AEs (0-3%) but similar for reoperations (0-1%) after standardization for differences in case mix. In a sub-analysis when the number of surgeries performed was restricted to more than 10 primary THAs annually to being evaluated, almost half or more of all the surgeons were excluded from the annual analysis. The result of this restriction was that all surgeons outside the control-limit disappeared after standardization for both AEs and reoperations for all the years investigated. Considering the complete period of 6 years, less than 1% (1 high-volume surgeon for AEs and 2 high-volume surgeons for reoperations) after risk adjustments were outside the 95% CI, and no surgeons were outside the 99.8% CI.Interpretation - In a Swedish setting, the variation in surgeon performance, as measured by AEs within 90 days and reoperations within 2 years following primary THA, was small and 3% or less of the surgeons were outside the 95% CI for the investigated years after adjustments for case mix. The risk for an individual surgeon to be regarded as having poor performance when creating surgeon-specific feedback in the SHAR is very low when volume and patient risk factors are considered.

Association between surgical volume and failure of primary total hip replacement in England and Wales: findings from a prospective national joint replacement register

OBJECTIVE

To investigate the association of volume of total hip arthroplasty (THA) between consultants and within the same consultant in the previous year and the hazard of revision using multilevel survival models.

DESIGN

Prospective cohort study using data from a national joint replacement register.

SETTING

Elective THA across all private and public centres in England and Wales between April 2003 and February 2017.

PARTICIPANTS

Patients aged 50 years or more undergoing THA for osteoarthritis.

INTERVENTION

The volume of THA conducted in the preceding 365 days to the index procedure.

MAIN OUTCOME AND MEASURE

Revision surgery (excision, addition or replacement) of a primary THA.

RESULTS

Of the 579 858 patients undergoing primary THA (mean baseline age 69.8 years (SD 10.2)), 61.1% were women. Multilevel survival found differing results for between and within-consultant effects. There was a strong volume-revision association between consultants, with a near-linear 43.3% (95% CI 29.1% to 57.4%) reduction of the risk of revision comparing consultants with volumes between 1 and 200 procedures annually. Changes in individual surgeons (within-consultant) case volume showed no evidence of an association with revision.

CONCLUSION

Separation of between-consultant and within-consultant effects of surgical volume reveals how volume contributes to the risk of revision after THA. The lack of association within-consultants suggests that individual changes to consultant volume alone will have little effect on outcomes following THA.These novel findings provide strong evidence supporting the practice of specialisation of hip arthroplasty. It does not support the practice of low-volume consultants increasing their personal volume as it is unlikely their results would improve if this is the only change. Limiting the exposure of patients to consultants with low volumes of THA and greater utilisation of centres with higher volume surgeons with better outcomes may be beneficial to patients.

Can Machine-learning Algorithms Predict Early Revision TKA in the Danish Knee Arthroplasty Registry?

BACKGROUND

Revision TKA is a serious adverse event with substantial consequences for the patient. As the demand for TKA rises, reducing the risk of revision TKA is becoming increasingly important. Predictive tools based on machine-learning algorithms could reform clinical practice. Few attempts have been made to combine machine-learning algorithms with data from nationwide arthroplasty registries and, to the authors' knowledge, none have tried to predict the likelihood of early revision TKA.

QUESTION/PURPOSES

We used the Danish Knee Arthroplasty Registry to build models to predict the likelihood of revision TKA within 2 years of primary TKA and asked: (1) Which preoperative factors were the most important features behind these models' predictions of revision? (2) Can a clinically meaningful model be built on the preoperative factors included in the Danish Knee Arthroplasty Registry?

METHODS

The Danish Knee Arthroplasty Registry collects patients' characteristics and surgical information from all arthroplasties conducted in Denmark and thus provides a large nationwide cohort of patients undergoing TKA. As training dataset, we retrieved all preoperative variables of 25,104 primary TKAs from 2012 to 2015. The same variables were retrieved from 6170 TKAs conducted in 2016, which were used as a hold-out year for temporal external validation. If a patient received bilateral TKA, only the first knee to receive surgery was included. All patients were followed for 2 years, with removal, exchange, or addition of an implant defined as TKA revision. We created four different predictive models to find the best performing model, including a regression-based model using logistic regression with least shrinkage and selection operator (LASSO), two classification tree models (random forest and gradient boosting model) and a supervised neural network. For comparison, we created a noninformative model predicting that all observations were unrevised. The four machine learning models were trained using 10-fold cross-validation on the training dataset after adjusting for the low percentage of revisions by over-sampling revised observations and undersampling unrevised observations. In the validation dataset, the models' performance was evaluated and compared by density plot, calibration plot, accuracy, Brier score, receiver operator characteristic (ROC) curve and area under the curve (AUC). The density plot depicts the distribution of probabilities and the calibration plot graphically depicts whether the predicted probability resembled the observed probability. The accuracy indicates how often the models' predictions were correct and the Brier score is the mean distance from the predicted probability to the observed outcome. The ROC curve is a graphical output of the models' sensitivity and specificity from which the AUC is calculated. The AUC can be interpreted as the likelihood that a model correctly classified an observation and thus, a priori, an AUC of 0.7 was chosen as threshold for a clinically meaningful model.

RESULTS

Based the model training, age, postfracture osteoarthritis and weight were deemed as important preoperative factors within the machine learning models. During validation, the models' performance was not different from the noninformative models, and with AUCs ranging from 0.57 to 0.60, no models reached the predetermined AUC threshold for a clinical useful discriminative capacity.

CONCLUSION

Although several well-known presurgical risk factors for revision were coupled with four different machine learning methods, we could not develop a clinically useful model capable of predicting early TKA revisions in the Danish Knee Arthroplasty Registry based on preoperative data.

CLINICAL RELEVANCE

The inability to predict early TKA revision highlights that predicting revision based on preoperative information alone is difficult. Future models might benefit from including medical comorbidities and an anonymous surgeon identifier variable or may attempt to build a postoperative predictive model including intra- and postoperative factors as these may have a stronger association with early TKA revisions.

Development and early findings of a semiautomated arthroplasty registry in a multi-institutional healthcare network

AIMS

The primary aim of this paper was to outline the processes involved in building the Partners Arthroplasty Registry (PAR), established in April 2016 to capture baseline and outcome data for patients undergoing arthroplasty in a regional healthcare system. A secondary aim was to determine the quality of PAR's data. A tertiary aim was to report preliminary findings from the registry and contributions to quality improvement initiatives and research up to March 2019.

METHODS

Structured Query Language was used to obtain data relating to patients who underwent total hip or knee arthroplasty (THA and TKA) from the hospital network's electronic medical record (EMR) system to be included in the PAR. Data were stored in a secure database and visualized in dashboards. Quality assurance of PAR data was performed by review of the medical records. Capture rate was determined by comparing two months of PAR data with operating room schedules. Linear and binary logistic regression models were constructed to determine if length of stay (LOS), discharge to a care home, and readmission rates improved between 2016 and 2019.

RESULTS

The PAR captured 16,163 THAs and TKAs between April 2016 and March 2019, performed in seven hospitals by 110 surgeons. Manual comparison to operating schedules showed a 100% capture rate. Review of the records was performed for 2,603 random operations; 2,298 (88.3%) had complete and accurate data. The PAR provided the data for three abstracts presented at international conferences and has led to preoperative mental health treatment as a quality improvement initiative in the participating institutions. For primary THA and TKA surgeries, the LOS decreased significantly (p < 0.001) and the rate of home discharge increased significantly (p < 0.001) between 2016 and 2019. Readmission rates did not correlated with the date of surgery (p = 0.953).

CONCLUSION

The PAR has high rates of coverage (the number of patients treated within the Partners healthcare network) and data completion and can be used for both research purposes and quality improvement. The same method of creating a registry that was used in the PAR can be applied to hospitals using similar EMR systems. Cite this article: Bone Joint J 2020;102-B(7 Supple B):90-98.

RSA-tested TKA Implants on Average Have Lower Mean 10-year Revision Rates Than Non-RSA-tested Designs

BACKGROUND

The number of revisions after TKA is expected to rise because of aging populations in many countries and because patients are undergoing TKA at younger ages. Aseptic loosening is a major reason for late revision, which can be predicted by radiostereometric analysis (RSA) of small groups of patients at 2 years of follow-up. RSA is therefore an ideal tool to assess new TKA designs before they are introduced to the market, although not every TKA design has been studied with RSA. If RSA-tested TKA designs have lower 10-year revision rates in national registries than non-RSA-tested TKA designs, RSA testing of all new designs could be advocated.

QUESTIONS/PURPOSES

In this study, we asked: Is there a difference in the all-cause revision rate between non-RSA-tested and RSA-tested TKA designs registered in national knee arthroplasty registries at 5 and 10 years of follow-up?

METHODS

Knee arthroplasty registries were identified through the European Federation of National Associations of Orthopaedics and Traumatology webpage and through a manual internet search. Inclusion criteria were a minimum follow-up duration of 10 years and available revision or survival data per TKA design. Twenty-six registries were identified; seven were included comprising 339 TKA designs, of which 236 designs were classified as RSA-tested and 103 as non-RSA-tested. Six registries were excluded because no report was published. One registry was excluded because no fixation method was mentioned (79 TKA designs). Another registry was excluded because there was no 10-year data available (22 non-RSA-tested designs; 10 RSA-tested designs). Eleven registries were excluded because they did not provide revision rates per design and had not reached 10 years follow-up. The revision rates with their standard errors were extracted per design. We used the data from a recent meta-analysis to identify whether a TKA design was previously tested with RSA. This meta-analysis found 53 RSA studies comprising 70 different TKA designs. The prosthesis model, fixation method and insert type were extracted from these RSA-studies. The design characteristics of the TKA reported in the knee arthroplasty registries were also extracted, and if possible, matched to the TKA designs reported in the RSA-studies. At 5 years of follow-up, 191 TKA designs were identified as non-RSA-tested and 92 were identified as RSA-tested. At 10 years of follow-up, 154 TKA designs and 74 TKA designs were classified as non-RSA-tested and RSA-tested, respectively. A random-effects model using the Metafor Package in R statistics was used to estimate the pooled revision rate at 5 and 10 years of follow-up for both groups. The difference in revision rates between groups at 5 and 10 years of follow-up was estimated by including RSA as a factor in the random-effects model.

RESULTS

Mean all-cause revision rates at 5 years for non-RSA-tested and RSA-tested implants were 3.6% (95% CI 3.4 to 3.8) and 2.9% (95% CI 2.7 to 3.0), with a mean difference of 0.6% favoring RSA-tested implants (95% CI 0.4 to 0.8; p < 0.001). Mean all-cause revision rates at 10 years for non-RSA-tested and RSA-tested implants were 5.5% (95% CI 5.2 to 5.9) and 4.4% (95% CI 4.1 to 4.7), with a mean difference of 0.9% favoring RSA-tested implants (95% CI 0.4 to 1.3; p < 0.001).

CONCLUSIONS

Although there are exceptions, across registries, TKA designs that have been tested in an RSA setting have a slightly lower (about 1%) mean all-cause revision rate at 5-year and 10-year follow-up than those tested in a non-RSA setting. Acknowledging the inherent limitations of this observational study, a risk difference of 1% could potentially translate into an approximate 20% decrease in revision burden up to 10 years, which may have a profound impact on patient morbidity and health-related costs.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Opportunities to improve feasibility, effectiveness and costs associated with a total joint replacements high-volume hospital registry

BACKGROUND

Clinical registries are powerful tools for collecting uniform data longitudinally, thus making it possible to evaluate the outcome of patients affected by a specific pathology. In the context of total joint arthroplasty, registries serve also as post-market surveillance. Adoption of registries is a heavy burden for clinical settings in terms of resources and infrastructures. Excessive workload leads to incomplete data collection which undermines the effectiveness of a registry and consequently the workload needs to be optimised.

METHODS

Starting from the use case of the Istituto Ortopedico Galeazzi, the time and personnel dedicated to the registry was estimated. Analysis of the data collected in the first years enabled us to propose a methodology for workload reduction. Different Machine Learning models were leveraged to predict patients with excellent satisfaction to reduce the number of assessments in their clinical post-operative follow-up. Moreover, feature selection was used to identify any unnecessary clinical scale to collect.

RESULTS

Given an acceptance rate of 3500 patients per year, 22 doctors and 6 non-medical employees were required to adopt a registry properly. Among the tested models, the Naïve Bayes gave the best performance (AUPRC = 0.81) in predicting patient satisfaction at six months. Moreover, we found that the 12-item Short Form was poorly informative in predicting satisfaction at six-months.

CONCLUSIONS

In this study machine learning was leveraged to provide a methodology to reduce workload in the use of pathology registries. Such workload reduction can have a considerable impact at a larger scale, and improve registry feasibility in high-volume hospitals.

Direct Anterior Approach in Total Hip Arthroplasty Leads to Superior Outcomes at 3-Month Follow-up When Compared With the Posterior Approach: A Matched Study Using Propensity Score Analysis

The purpose of this study was to report and compare early outcomes during the first 3 months of the recovery phase in patients who underwent primary total hip arthroplasty (THA) with direct anterior approach (DAA) and posterior approach (PA).

Peri-Prosthetic Joint Infection after Finger Joint Arthroplasty

Background: Endoprosthetic treatment of finger joints is an established procedure. However, data on peri-prosthetic finger joint infections (PJI) are rare. The goal of this retrospective study was to assess infection rates and treatment outcomes after PJI of the finger joints. Methods: Between 1984 and 2014, 1,195 finger joints (978 metacarpal and 217 proximal interphalangeal [PIP] joints) in 518 patients were treated. A retrospective record analysis was conducted. Besides demographic data, infection rates, types of revision surgery, and treatment outcomes were evaluated. Treatment strategies changed during the treatment period. Routinely assessed patient-reported outcome measures, namely the QuickDASH score, visual analogue scale (VAS), an everyday function score (activities of daily living; ADL), and an adapted Clayton score, were compared. Results: In 36 finger joints of 30 patients, a post-operative peri-prosthetic infection could be identified (3%). Infections occurred on average 3.8 years after arthroplasty. For meta-carpal phalangeal (MCP) joints, the best clinical outcomes could be observed after a two-stage revision procedure (QuickDASH score 86). Arthrodesis performed in a one-stage procedure achieved favorable outcomes in PIP joints (QuickDASH score 89). Re-infection mandating revision surgery occurred in seven joints in five patients (7/36; 19.4%). In 25 patients with 29 finger joints, there was no re-infection and no need for revision. Conclusion: Peri-prosthetic infection of finger joint prostheses occurs in approximately 3% of all cases, which is a higher rate than in the more common hip and knee procedures. For MCP joint revision surgery, a two-stage procedure seems to be the best treatment choice. For PIP joint revision, a single-stage revision with arthrodesis in a functional position achieves a good outcome.

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.