A retrospective analysis of trends in primary knee arthroplasty in Germany from 2008 to 2018

Unicondylar knee arthroplasty demonstrating a significant increased risk for aseptic revisions compared to unconstrained and constrained total knee arthroplasty: An analysis of aseptic revisions after unicondylar and primary total knee arthroplasty of the German Arthroplasty Registry

PURPOSE

Due to ageing population, the implantation rate of total knee arthroplasties (TKAs) is continuously growing. Aseptic revisions in primary knee arthroplasty are a major cause of revision. The aim of the following study was to determinate the incidence and reasons of aseptic revisions in constrained and unconstrained TKA, as well as in unicondylar knee arthroplasties (UKAs).

METHODS

Data collection was performed using the German Arthroplasty Registry. Reasons for aseptic revisions were calculated. Incidence and comparison of aseptic revisions were analysed using Kaplan-Meier estimates. A multiple χ2 test with Holm's method was used to detect group differences in ligament ruptures.

RESULTS

Overall, 300,998 cases of knee arthroplasty with 254,144 (84.4%) unconstrained TKA, 9993 (3.3%) constrained TKA and 36,861 (12.3%) UKA were analysed. Aseptic revision rate in UKA was significantly increased compared to unconstrained and constrained TKA (p < 0.0001). In constrained TKA, a 2.0% revision rate for aseptic reasons were reported after 1 year, while in unconstrained TKA 1.1% and in UKA, 2.7% of revisions were identified. After 7 years in constrained TKA 3.3%, in unconstrained TKA 2.8%, and in UKA 7.8% sustained aseptic revision. Ligament instability was the leading cause of aseptic revision accounting for 13.7% in unconstrained TKA. In constrained TKA, 2.8% resulted in a revision due to ligament instability. In the UKA, the most frequent cause of revisions was tibial loosening, accounting for 14.6% of cases, while progression of osteoarthritis accounted for 7.9% of revisions. Ligament instability was observed in 14.1% of males compared to 15.9% of females in unconstrained TKA and in 4.6% in both genders in UKA.

CONCLUSION

In patients with UKA, aseptic revision rates are significantly higher compared to unconstrained and constrained TKA. Ligament instability was the leading cause of aseptic revision in unconstrained TKA. In UKA, the most frequent cause of revisions was tibial loosening, while progression of osteoarthritis was the second most frequent cause of revisions. Comparable levels of ligament instability were observed in both sexes.

LEVEL OF EVIDENCE

Level III, cohort study.

The reimbursement system can influence the treatment choice and favor joint replacement versus other less invasive solutions in patients affected by osteoarthritis

PURPOSE

The aim of this study was to assess how physicians perceive the role of the reimbursement system and its potential influence in affecting their treatment choice in the management of patients affected by osteoarthritis (OA).

METHODS

A survey was administered to 283 members of SIAGASCOT (Italian Society of Arthroscopy, Knee, Upper Limb, Sport, Cartilage and Orthopaedic Technologies), a National scientific orthopaedic society. The survey presented multiple choice questions on the access allowed by the current Diagnosis-Related Groups (DRG) system to all necessary options to treat patients affected by OA and on the influence toward prosthetic solutions versus other less invasive options.

RESULTS

Almost 70% of the participants consider that the current DRG system does not allow access to all necessary options to best treat patients affected by OA. More than half of the participants thought that the current DRG system favors the choice of prosthetic solutions (55%) and that it can contribute to the increase in prosthetic implantation at the expense of less invasive solutions (54%). The sub-analyses based on different age groups, professional roles, and places of work allowed to evaluate the response in each specific category, confirming the findings for all investigated aspects.

CONCLUSIONS

This survey documented that the majority of physicians consider that the reimbursement system can influence the treatment choice when managing OA patients. The current DRG system was perceived as unbalanced in favor of the choice of the prosthetic solution, which could contribute to the increase in prosthetic implantation at the expense of other less invasive options for OA management.

Total knee arthroplasty in France: Male-driven rise in procedures in 2009-2019 and projections for 2050

BACKGROUND

The number of Total Knee Arthroplasty (TKA) procedures has been rising steadily for several decades in Europe and the USA. The increase varies in pace across countries, with a gradual climb in northern and central Europe, a slowing in the USA, and an exponential surge in the UK. In France, a 32.2% rise in the number of TKA and unicompartmental knee arthroplasty procedures was documented between 2012 and 2018. However, no study has focussed specifically on changes in both TKA procedures and the features of TKA patients. The objective of this study was to use the French national healthcare database to evaluate (1) increases in TKA procedures according to sex and age, (2) whether TKA is being performed at increasingly younger ages, (3) whether the comorbidity profile at TKA is changing, and (4) whether the TKA incidence rate will stabilise in the future, with a projection for 2050.

HYPOTHESIS

In France, the number of TKA procedures is rising in both males and females but the pace of the increases differs between sexes.

MATERIAL AND METHOD

This study used data collected in France in 2009-2019, separately for different age groups and for males and females, in the French national healthcare database (Système national des données de santé, SNDS) that collects information on all surgical procedures performed nationwide. Based on information about the TKA procedures, we determined (1) the TKA incidence rates with their time trends and (2) indirectly, the comorbidity profiles of the patients at TKA. Linear, Poisson, and logistic models were built to predict incidence rates in 2030, 2040, and 2050.

RESULTS

Between 2009 and 2019, the TKA incidence rate showed a steeper increase in males than in females (from 71.2 to 122.9 [+73%] vs. 124.2 to 181.0 [+46%], respectively). Although this increase was replicated in all age groups, it was sharper in patients younger than 65 years, in both males and females (from 20.9 to 37.9 [+82%] and 33.6 to 51.3 [+53%], respectively). During the study period, the number and proportion of patients increased in the group with mild comorbidities (from 40 093 to 67 430 TKAs, i.e., from 53.1% to 65.7% of all TKAs) but not in the other comorbidity groups. All projection models were validated. Nonetheless, the most likely scenario, provided by the logistic model, is a 33% rise by 2050 in both males and females (i.e., to 151 575 TKA procedures) with a plateau starting around 2030.

CONCLUSION

Although the increase in TKA procedures is more marked in males than in females, the trends are similar in both sexes, with a sharper rise in the group younger than 65 years and a shift toward patients with milder comorbidities. In the longer term, incidence rate trends follow logistic dynamics, with a plateau starting around 2030. To meet the increasing demand, a corresponding development in relevant healthcare resources must be planned.

LEVEL OF EVIDENCE

IV, descriptive epidemiological study.

Rehabilitation during early postoperative period following total knee arthroplasty using single-joint hybrid assistive limb as new therapy device: a randomized, controlled clinical pilot study

INTRODUCTION

The first weeks after total knee arthroplasty (TKA) are crucial for the functional outcome. To improve knee mobility, a continuous passive motion (CPM) motor rail is commonly used during in-hospital rehabilitation. The single-joint hybrid assistive limb (HAL-SJ) is a new therapy device. The aim of the study was to improve patients' range of motion (ROM), mobility, and satisfaction using the active-assistive support of the HAL-SJ.

MATERIALS AND METHODS

Between 09/2017 and 10/2020, 34 patients, who underwent TKA and matched the inclusion criteria, were randomized into study (HAL-SJ) and control (CPM) group. Treatment began after drain removal and was carried out until discharge. Primary outcome parameters were raised pre- and postoperatively and included the Oxford knee score (OKS), visual analog scale (VAS), and acquired range of motion. Furthermore complications caused by the device were recorded.

RESULTS

OKS increased in both groups postoperatively, but only significantly in the HAL-SJ group. Postoperative pain improved in both groups without significant differences. Flexion improvement was significant in both groups between days 3/7 and 8 weeks postoperatively. We did not encounter any complications related to HAL-SJ.

CONCLUSIONS

In conclusion, use of the HAL-SJ during rehabilitation in the early postoperative period after TKA was safe without disadvantages compared to the control group and seems to have advantages in terms of daily life impairment.

Revision arthroplasty after unicompartimental knee arthroplasty

Background

Unicompartimental knee arthroplasty (UKA) is a promising and increasing application to treat unicompartimental knee osteoarthritis. However, revision arthroplasty numbers after UKA are unknown. Therefore, aim of this study was to determine the nationwide burden of revision after UKA by answering the following questions: (1) How did numbers of revision UKA procedures developed over the last decade as a function of age and gender? (2) How high is the percentage of revision UKA procedures due to infection? (3) Which therapy strategy was chosen for surgical treatment of aseptic revision UKA?

Methods

Revision arthroplasty rates as a function of age, gender, infection and type of prosthesis were quantified based on Operation and Procedure Classification System codes using revision knee arthroplasty data from 2008 to 2018, provided by the Federal Statistical Office of Germany (Destatis).

Results

Over the last decade, revision UKA increased by 46.3% up to 3105 procedures in 2018. A trend towards higher numbers in younger patients was observed. Septic interventions constituted 5.7% of all revisions, whereby total procedures increased by 67.1% from 2008 through 2018. The main treatment strategy was an exchange to a bicondylar surface replacement prosthesis, which was done in 63.70% of all cases, followed by exchange to a femoral and tibial shaft-anchored (16.2% of all revisions).

Conclusion

The increasing number of revision arthroplasty after UKA in Germany, especially in younger patients and due to infection, underlines the need for future efforts to improve treatment strategies beyond UKA to delay primary arthroplasty and avoid periprosthetic joint infection.