Does knee replacement surgery for osteoarthritis improve survival? The jury is still out

Pre-operative pain pressure threshold association with patient satisfaction following Total Knee Arthroplasty

Background

Total knee arthroplasty (TKA) is commonly performed for the treatment of knee osteoarthritis (KOA). Poor satisfaction continues to be seen after TKA. Whilst reasons for poor patient satisfaction are multifactorial, there is a strong correlation with persistent pain following TKA. Studies have shown an association between local and remote mechanical hypersensitivity, measured using pressure pain thresholds (PPTs), and severity of knee osteoarthritis and functional status. We aimed to determine if the pre-operative PPTs were associated with patient satisfaction following TKA.

Methods

A prospective longitudinal study of 77 individuals was undertaken. Regression modelling assessed the relationship between Patient Satisfaction using the Knee Society Score (satisfaction subscale) following TKA for KOA, and PPTs recorded pre-operatively locally and remote to the affected knee, while accounting for potentially confounding patient demographic and psychosocial factors.

Results

Lower PPTs (indicating increased mechanical hypersensitivity) locally and remote to the operative knee were modestly associated with lower patient satisfaction in the short-term (six weeks) following TKA (β 0.25-0.28, adjR2 = 0.14-0.15), independent of demographic or psychosocial influences. However, this relationship progressively diminished in the intermediate and long-term post TKA.

Conclusion

While pre-operative PPT measures may provide some foresight to patient satisfaction post TKA in the short term, these measures appear to provide little insight to patient satisfaction in the intermediate and longer term.

Assessing the Mortality Rate After Primary Total Knee Arthroplasty: An Observational Study to Inform Future Economic Analysis

BACKGROUND

Previous research has focused on the perioperative or short-term (<1 year) mortality rate of total knee arthroplasty (TKA), leaving the long-term (>1 year) mortality rate unresolved. In this study, we calculated the mortality rate up to 15 years after primary TKA.

METHODS

Data from the New Zealand Joint Registry from April 1998 to December 2021 were analyzed. Patients aged 45 years or older who underwent TKA for osteoarthritis were included. Mortality data were linked with national records from births, deaths, and marriages. To determine the expected mortality rates in the general population, age-sex-specific life tables from statistics New Zealand were used. Mortality rate was presented as standardized mortality ratios (SMRs) - a comparison of relative mortality rate between the TKA and general populations. In total, 98,156 patients with a median follow-up of 7.25 years (range, 0.00 to 23.74) were included.

RESULTS

Over the entire follow-up period, 22,938 patients (23.4%) had died. The overall SMR for the TKA cohort was 1.08 (95% confidence interval (CI): 1.06 to 1.09), suggesting that TKA patients have an 8% higher mortality rate compared to the general population. However, a reduction in short-term mortality rate was observed for TKA patients up to 5 years post TKA (SMR 5 years post TKA; 0.59 95% CI: 0.57 to 0.60]). On the contrary, a significantly increased long-term mortality rate was observed in TKA patients with greater than 11 years of follow-up, particularly in men over the age of 75 years (SMR 11 to 15 years post TKA for males ≥ 75 years; 3.13 [95% CI: 2.95 to 3.31]).

CONCLUSION

The results suggest a reduction in short-term mortality rate for patients who undergo primary TKA. However, there is an increased long-term mortality rate particularly in men over the age of 75 years. Importantly, the mortality rates observed in this study cannot be causally attributed to TKA alone.

Chinese guidelines for the rehabilitation treatment of knee osteoarthritis: An CSPMR evidence-based practice guideline

BACKGROUND

Knee osteoarthritis (KOA) is the most common degenerative joint disease in China, causing a huge economic burden on patients, families, and society. Standardized KOA rehabilitation treatment is an important means to prevent and treat the disease and promote the development of high-quality medical services. This guideline is updated on the basis of the 2016 and 2019 editions.

METHODS

Clinical questions regarding rehabilitation assessment and treatment were selected through clinical questions screening and deconstruction, and multiple rounds of Delphi questionnaire consultation. The International Classification of Functioning, Disability and Health (ICF) was used as the theoretical framework, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) method was used to grade the quality of evidence and recommendations.

RESULTS

The reporting of this guideline followed the standard of Reporting Items for Practice Guidelines in Healthcare (RIGHT). Taking into account patients' preferences and values and the needs of Chinese clinical practice, a total of 11 clinical questions and 28 recommendations were established. The clinical questions were grouped into two categories: KOA assessment (body function, body structure, activity and participation, quality of life, and environmental factors and clinical outcomes assessment, resulting in 9 recommendations) and KOA treatment (health education, therapeutic exercise, therapeutic modalities, occupational therapy, assistive devices, and regenerative rehabilitation approaches, resulting in 19 recommendations).

CONCLUSION

This is the first evidence-based guideline for KOA rehabilitation in China utilizing the ICF framework. This guideline provides key guidance for developing systematic, standardized, and precise rehabilitation protocols for KOA across various healthcare settings.

A machine learning approach reveals features related to clinicians' diagnosis of clinically relevant knee osteoarthritis

OBJECTIVES

To identify highly ranked features related to clinicians' diagnosis of clinically relevant knee OA.

METHODS

General practitioners (GPs) and secondary care physicians (SPs) were recruited to evaluate 5-10 years follow-up clinical and radiographic data of knees from the CHECK cohort for the presence of clinically relevant OA. GPs and SPs were gathered in pairs; each pair consisted of one GP and one SP, and the paired clinicians independently evaluated the same subset of knees. A diagnosis was made for each knee by the GP and SP before and after viewing radiographic data. Nested 5-fold cross-validation enhanced random forest models were built to identify the top 10 features related to the diagnosis.

RESULTS

Seventeen clinician pairs evaluated 1106 knees with 139 clinical and 36 radiographic features. GPs diagnosed clinically relevant OA in 42% and 43% knees, before and after viewing radiographic data, respectively. SPs diagnosed in 43% and 51% knees, respectively. Models containing top 10 features had good performance for explaining clinicians' diagnosis with area under the curve ranging from 0.76-0.83. Before viewing radiographic data, quantitative symptomatic features (i.e. WOMAC scores) were the most important ones related to the diagnosis of both GPs and SPs; after viewing radiographic data, radiographic features appeared in the top lists for both, but seemed to be more important for SPs than GPs.

CONCLUSIONS

Random forest models presented good performance in explaining clinicians' diagnosis, which helped to reveal typical features of patients recognized as clinically relevant knee OA by clinicians from two different care settings.

The role of endothelin and RAS/ERK signaling in immunopathogenesis-related fibrosis in patients with systemic sclerosis: an updated review with therapeutic implications

Systemic sclerosis (SSc) is a disease of connective tissue with high rate of morbidity and mortality highlighted by extreme fibrosis affecting various organs such as the dermis, lungs, and heart. Until now, there is no specific cure for the fibrosis occurred in SSc disease. The SSc pathogenesis is yet unknown, but transforming growth factor beta (TGF-β), endothelin-1 (ET-1), and Ras-ERK1/2 cascade are the main factors contributing to the tissue fibrosis through extracellular matrix (ECM) accumulation. Several studies have hallmarked the association of ET-1 with or without TGF-β and Ras-ERK1/2 signaling in the development of SSc disease, vasculopathy, and fibrosis of the dermis, lungs, and several organs. Accordingly, different clinical and experimental studies have indicated the potential therapeutic role of ET-1 and Ras antagonists in these situations in SSc. In addition, ET-1 and connective tissue growth factor (CTGF) as a cofactor of the TGF-β cascade play a substantial initiative role in inducing fibrosis. Once initiated, TGF-β alone or in combination with ET-1 and CTGF can activate several kinase proteins such as the Ras-ERK1/2 pathway that serve as the fundamental factor for developing fibrosis. Furthermore, Salirasib is a synthetic small molecule that is able to inhibit all Ras forms. Therefore, it can be used as a potent therapeutic factor for fibrotic disorders. So, this review discusses the role of TGF-β/ET-1/Ras signaling and their involvement in SSc pathogenesis, particularly in its fibrotic situation.

Proton pump inhibitor therapy and risk of knee replacement surgery: a general population-based cohort study

OBJECTIVE

Proton pump inhibitors (PPIs) are among the most commonly used medications for patients with osteoarthritis (OA). Various types of PPIs have different impacts on lowering serum magnesium level that may affect knee OA progression. We aimed to compare the risk of clinically relevant endpoint of knee replacement (KR) among initiators of five different PPIs with that among histamine-2 receptor antagonist (H2RA) initiators.

DESIGN

Among patients with knee OA (≥50 years) in The Health Improvement Network database in the UK we conducted five sequential propensity-score matched cohort studies to compare the risk of KR over 5-year among patients who initiated omeprazole (n = 2,672), pantoprazole (n = 664), lansoprazole (n = 3,747), rabeprazole (n = 751), or esomeprazole (n = 827) with those who initiated H2RA.

RESULTS

The prevalence of PPI prescriptions among participants with knee OA increased from 12.7% in 2000-44.0% in 2017. Two-hundred-and-seventy-four KRs (30.8/1,000 person-years) occurred in omeprazole initiators and 230 KRs (25.4/1,000 person-years) in H2RA initiators. Compared with H2RA initiators, the risk of KR was 21% higher in omeprazole initiators (hazard ratio [HR] = 1.21,95% confidence interval [CI]:1.01-1.44). Similar results were observed when pantoprazole use was compared with H2RA use (HR = 1.38,95%CI:1.00-1.90). No such an increased risk of KR was observed among lansoprazole (HR = 1.06,95%CI:0.92-1.23), rabeprazole (HR = 0.97,95%CI:0.73-1.30), or esomeprazole (HR = 0.83,95%CI:0.60-1.15) initiators compared with that among H2RA initiators.

CONCLUSIONS

In this population-based cohort study, initiation of omeprazole or pantoprazole use was associated with a higher risk of KR than initiation of H2RA use. This study raises concern regarding an unexpected risk of omeprazole and pantoprazole on accelerating OA progression.

Does smoking cessation increase risk of knee replacement? a general population-based cohort study

OBJECTIVE

Smoking represents a major issue for global public health. Owing to methodologic challenges, findings of an association between smoking and risk of knee osteoarthritis (OA) are inconsistent. We sought to assess the relation of onset of smoking cessation to the risk of OA sequelae, i.e., knee replacement, and to perform sub-cohort analysis according to weight change after smoking cessation.

DESIGN

Using The Health Improvement Network, we conducted a cohort study to examine the association between smoking cessation and risk of knee replacement among patients with knee OA. Participants who stopped smoking were further grouped into three sub-cohorts: weight gain (body mass index [BMI] increased>1.14 kg/m²), no substantial weight change (absolute value of BMI change<1.14 kg/m²), and weight loss (BMI loss>1.14 kg/m²) after smoking cessation.

RESULTS

We identified 108 cases of knee replacement among 1,054 recent quitters (26.7/1,000 person-years) and 1,108 cases among 15,765 current smokers (17.4/1,000 person-years). The rate difference of knee replacement in recent quitter cohort vs current smoker cohort was 10.4 (95% confidence interval [CI]:5.3-15.6)/1,000 person-years and the adjusted hazard ratio (HR) was 1.30 (95%CI:1.05-1.59). Compared with current smokers, risk of knee replacement was higher among quitters with weight gain (HR = 1.42,95%CI:1.01-1.98), but not among those with no substantial weight change (HR = 1.29,95%CI:0.90-1.83) or those with weight loss (HR = 1.11,95%CI:0.71-1.75).

CONCLUSIONS

Our large population-based cohort study provides the first evidence that smoking cessation was associated with a higher risk of knee replacement among individuals with knee OA, and such an association was due to weight gain after smoking cessation.

Risk of venous thromboembolism in knee, hip and hand osteoarthritis: a general population-based cohort study

OBJECTIVES

Osteoarthritis is a leading cause of immobility and joint replacement, two strong risk factors for venous thromboembolism (VTE). We aimed to examine the relation of knee, hip and hand osteoarthritis to the risk of VTE and investigate joint replacement as a potential mediator.

METHODS

We conducted three cohort studies using data from The Health Improvement Network. Up to five individuals without osteoarthritis were matched to each case of incident knee (n=20 696), hip (n=10 411) or hand (n=6329) osteoarthritis by age, sex, entry time and body mass index. We examined the relation of osteoarthritis to VTE (pulmonary embolism and deep vein thrombosis) using a multivariable Cox proportional hazard model.

RESULTS

VTE developed in 327 individuals with knee osteoarthritis and 951 individuals without osteoarthritis (2.7 vs 2.0 per 1000 person-years), with multivariable-adjusted HR being 1.38 (95% CI 1.23 to 1.56). The indirect effect (HR) of knee osteoarthritis on VTE through knee replacement was 1.07 (95% CI 1.01 to 1.15), explaining 24.8% of its total effect on VTE. Risk of VTE was higher in hip osteoarthritis than non-osteoarthritis (3.3 vs 1.8 per 1000 person-years; multivariable-adjusted HR=1.83, 95% CI 1.56 to 2.13). The indirect effect through hip replacement yielded an HR of 1.14 (95% CI 1.04 to 1.25), explaining 28.1% of the total effect. No statistically significant difference in VTE risk was observed between hand osteoarthritis and non-osteoarthritis (1.5 vs 1.6 per 1000 person-years; multivariable-adjusted HR=0.88, 95% CI 0.67 to 1.16).

CONCLUSION

Our large population-based cohort study provides the first evidence that knee or hip osteoarthritis, but not hand osteoarthritis, was associated with an increased risk of VTE, and such an association was partially mediated through knee or hip replacement.

Thiazide diuretics and risk of knee replacement surgery among patients with knee osteoarthritis: a general population-based cohort study

OBJECTIVE

Thiazide diuretic use is associated with higher bone mineral density (BMD) and possibly lower serum magnesium levels than loop diuretic use, and both high BMD and low serum magnesium have been linked to high prevalent knee osteoarthritis. This study aimed to compare the risk of a clinically relevant endpoint, knee replacement (KR) surgery, among initiators of thiazide and loop diuretics.

DESIGN

Among patients aged ≥50 years with a diagnosis of knee osteoarthritis in The Health Improvement Network (THIN) in United Kingdom, we conducted a propensity score-matched cohort study to examine the relation of thiazide diuretic initiation vs loop diuretic initiation to the risk of KR over 5 years.

RESULTS

Among thiazide and loop diuretic initiators (n = 3,488 for each group; mean age: 73 years; female ratio: 59%), 359 (28.6/1,000 person-years) and 283 (24.1/1,000 person-years) KRs occurred during the follow-up period, respectively. The hazard ratio (HR) of KR for thiazide diuretic initiation vs loop diuretic initiation was 1.26 (95% confidence interval [CI]: 1.08-1.47). The adherence-adjusted HR of KR for continuous use of thiazide diuretics was 1.44 (95% CI: 1.21-1.72).

CONCLUSIONS

In this population-based cohort of patients with knee osteoarthritis, thiazide diuretic use was associated with a higher risk of KR than loop diuretic use. This association may potentially be due to thiazide diuretics' effect on BMD and serum magnesium.

How Does Mortality Risk Change Over Time After Hip and Knee Arthroplasty?

BACKGROUND

Mortality after THA and TKA is lower than expected for several years after surgery when compared with age- and sex-adjusted population data. With long-term followup (beyond approximately 10 years), some evidence has suggested that this trend reverses, such that postsurgical mortality is higher than expected as more time passes. However, the degree to which this may be the case has not been clearly established.

QUESTIONS/PURPOSES

In this large-registry study, we asked: What is the long-term mortality after THA and TKA compared with the expected mortality, adjusted for age, sex, and calendar year.

METHODS

Using data on 243,057 THAs and 363,355 TKAs performed for osteoarthritis from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 2003 to 2016, and life tables from the Australian Bureau of Statistics the Standardised Mortality Ratio (SMR), relative mortality and excess mortality (relative to the expected mortality for people of the same sex and age in the same country) was calculated separately for hips and knees. The AOANJRR contains near-complete (98%-100%) data from all hospitals in Australia performing arthroplasty but does not include followup data on people who have left the country. Followup was from the date of surgery to 13 years, mean 5.8 years.

RESULTS

We found a lower-than-expected mortality for THA and TKA in the early years after surgery. This association diminished over time and the mortality became higher than expected after 12 years for both THA and TKA. For THA, the excess mortality (per thousand people) increased from 11 fewer deaths (95% CI, 10-11 fewer) after 1 year to four more deaths (95% CI, 0-9 more) in the 13th year, and the SMR increased from 0.50 (95% CI, 0.48-0.52) after 1 year to 1.07 (95% CI, 0.99-1.14) in the 13th year. For TKA, the excess mortality (per thousand people) increased from 12 fewer deaths (95% CI, 12-13 fewer) after 1 year to five more deaths (95% CI 2-9 more) in the 13th year, and the SMR increased from 0.39 (95% CI, 0.37-0.40) after 1 year to 1.09 (95% CI, 1.03-1.15) in the 13th year.

CONCLUSIONS

Mortality after hip and knee arthroplasty is lower than expected (based on population norms) in the first 8 years to 9 years but gradually increases over time, becoming higher than expected after 12 years. The lower-than-expected mortality in the early years after surgery is likely the result of patient selection with patients undergoing primary arthroplasty having better health at the time of surgery than that of the age- and sex-matched population. The increasing mortality over time cannot be regression to the mean, as late mortality is higher than expected, moving beyond the mean. It is important to understand if there are modifiable factors associated with this increased mortality. The reasons for the change are uncertain. Factors to consider in future research include determining the effect of different patient factors on late mortality. Some of these included higher obesity rates for joint replacement patients and the association or causal impact of osteoarthritis and/or its treatment to increase late mortality in a similar manner to other forms of arthritis. There is also a possibility that the arthroplasty device itself may affect late mortality.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Long-Term Mortality Trends After Revision Total Knee Arthroplasty

BACKGROUND

Long-term mortality following primary total knee arthroplasty (TKA) is lower than the general population. However, it is unknown whether this is true in the setting of revision TKA. We examined long-term mortality trends following revision TKA.

METHODS

This retrospective study included 4907 patients who underwent 1 or more revision TKA between 1985 and 2015. Patients were grouped by surgical indications and followed until death or October 2017. The observed number of deaths was compared to the expected number of deaths using standardized mortality ratios (SMR) and Poisson regression models.

RESULTS

Compared to the general population, patients who underwent revision TKA for infection (SMR, 1.45; 95% confidence interval [CI], 1.33-1.57; P < .0001) and fracture (SMR, 1.16; 95% CI, 1.00-1.34; P = .04) experienced a significantly higher mortality risk. Patients who underwent revision TKA for infection and fracture experienced excess mortality soon after surgery which became more pronounced over time. In contrast, the mortality risk among patients who underwent revision TKA for loosening and/or bearing wear was similar to the general population (SMR, 0.95; 95% CI, 0.89-1.02; P = .16). Aseptic loosening and/or wear and instability patients had improved mortality initially; however, there was a shift to excess mortality beyond 5 years among instability patients, and beyond 10 years among aseptic loosening and/or wear patients.

CONCLUSION

Mortality is elevated soon after revision TKA for infection and fracture. Mortality is lower than the general population after revision TKA for loosening and/or bearing wear but gets worse than the general population beyond the first postoperative decade.

Effect of bisphosphonates on knee replacement surgery

PURPOSE

Bone remodelling as a therapeutic target in knee osteoarthritis (OA) has gained much interest, but the effects of antiresorptive agents on knee OA have been conflicting, with no studies to date examining the effects of bisphosphonate use on the clinically relevant endpoint of knee replacement (KR) surgery.

METHODS

We used data from The Health Improvement Network (THIN), a general practitioner electronic medical records representative of the general UK population. We identified older women who had initiated bisphosphonate use after their incident knee OA diagnosis. Each bisphosphonate initiator was propensity score-matched with a non-initiator within each 1-year cohort accrual block. The effect of bisphosphonates on the risk of KR was assessed using Cox proportional hazard regression. Sensitivity analyses to address residual confounding were also conducted.

RESULTS

We identified 2006 bisphosphonate initiators, who were matched to 2006 non-initiators(mean age 76, mean body mass index 27), with mean follow-up time of 3 years. The crude incidence rate of KR was 22.0 per 1000 person-years among the initiators, and 29.1 among the non-initiators. Bisphosphonate initiators had 26% lower risk of KR than non-initiators(HR 0.74, 95% CI 0.59 to 0.93); these results were similar when additionally adjusted for potential confounders in the propensity score (HR 0.76, 95% CI 0.60 to 0.95). Results of sensitivity analyses supported this protective effect.

CONCLUSIONS

In this population-based cohort of older women with incident knee OA, those with incident bisphosphonate users had lower risk of KR than non-users of bisphosphonates, suggesting a potential beneficial effect of bisphosphonates on knee OA.