The incidence of knee arthroplasty for primary osteoarthritis grows rapidly among baby boomers: A population‐based study in Finland

Objective

Total knee arthroplasty (TKA) is a commonly used treatment for severe primary knee osteoarthritis (OA) that is refractory to conservative treatment. Despite the presumed increase in the use of this treatment modality in younger patients, there are few published data concerning this. The aim of our study was to examine the changes in the age‐ and sex‐standardized incidence of TKA and unicondylar knee arthroplasty (UKA) in Finland during 1980–2006 and to identify factors that might affect the incidence during this period.

Methods

We obtained data on UKAs and TKAs from the Finnish Arthroplasty Registry and population data from Statistics Finland to analyze the incidence of UKAs and TKAs in Finland for the period 1980–2006. The effects of sex, age group, and hospital volume on the incidence of these procedures were also evaluated.

Results

The annual cumulative incidence of UKAs and TKAs has increased rapidly from 1980 to 2006 among 30–59‐year‐old inhabitants of Finland. For UKAs, the incidence increased from 0.2 per 100,000 inhabitants to 10 per 100,000, and for TKAs, the incidence increased from 0.5 per 100,000 to 65 per 100,000. The incidence remained higher among women during the entire study period. Most of the increase occurred among patients ages 50–59 years. The incidence grew more rapidly in low‐volume and intermediate‐volume hospitals.

Conclusion

We demonstrated a rapid increase in the incidence of arthroplasty among patients with primary knee OA in Finland, especially in those ages 50–59 years. There was no single explanatory factor behind this finding, although some of the growth might be due to the increased incidence noted in low‐ and intermediate‐volume hospitals.

     

The incidence and risk factors of contralateral knee arthroplasty after primary unilateral unicompartmental knee arthroplasty

Unicompartmental knee arthroplasty (UKA) is one of the commonly used surgical methods for unicompartmental osteoarthritis in recent years. Although the prognosis of the operated knee has been widely studied, there are relatively little data on the natural history of the contralateral knee after unilateral replacement. The aim of this study was to explore the incidence and risk factors of consequential knee arthroplasty in patients with bilateral knee osteoarthritis (KOA) after receiving primary unilateral UKA, so as to provide a theoretical basis for making a more comprehensive treatment strategy for patients with KOA.We conducted a retrospective study and enrolled patients with bilateral KOA received unilateral UKA from June 2015 to December 2019 in the third department of joint orthopedics, the third hospital of Hebei Medical University. The patients were divided into replacement group and non-replacement group according to whether the contralateral knee joint received knee arthroplasty. Information about treatment of contralateral knee joint was collected from medical records to determine the incidence. Univariate analysis and multivariate logistic regression analysis were performed to identify the independent risk factors.A total of 502 patients were enrolled in this study. The incidence of contralateral knee arthroplasty was 38.64%. In the univariate analysis, vertical angle of mechanical axis, knee joint''s internal and external joint space, Kellgren–Lawrence (K-L) classification, femoral tibial angle were the significant risk factors for contralateral knee arthroplasty. In the multivariate model, only vertical angle of mechanical axis ≥3.03° (odds ratio [OR] 4.36, 95% confidence interval [CI], 2.47–9.11), K-L classification grades 3 and 4 (OR 2.46,3.72; 95%CI, 1.31–4.25, 1.98–6.87), and femoral tibial angle ≥187.32° (OR 6.32, 95%, 2.23–18.87) remained associated with the occurrence of knee arthroplasty.About a quarter of patients with bilateral KOA received unilateral UKA will receive contralateral knee arthroplasty. Higher K-L classification, femoral tibial angle, and mechanical axis vertical angle are identified risk factors.     

Total knee arthroplasty for osteoarthritis of the knee

The indication, preoperative condition, surgical technique and postoperative rehabilitation of total knee arthroplasty for osteoarthritis are summarized. I think the point of contributing to the success of total knee arthroplasty are to discuss the preoperative condition, to know well the instrument, to do the accurate osteotomy and to obtain the correct soft tissue balancing.     

The risk of contralateral total knee arthroplasty after knee replacement for osteoarthritis

OBJECTIVE: Osteoarthritis (OA) is the most common indication for total knee arthroplasty (TKA), but the rate of contralateral disease progression after unilateral TKA as well as risk factors that may predict progression have not been determined. We assessed the overall rate of contralateral knee replacement after initial TKA for OA as a marker of progression to advanced symptomatic OA. METHODS: A total of 117 consecutive patients undergoing unilateral TKA for OA between 1983 and 1988 were evaluated and followed longitudinally for up to 14 years. Evaluation of potential risk factors for progression to contralateral TKA included age, sex, side of surgery, body mass index (BMI), and Kellgren-Lawrence (K-L) grade. RESULTS: The contralateral knee progressed to TKA in 31 patients, yielding an overall 10-year risk of contralateral TKA of 37.2%. The baseline K-L grade of the contralateral knee was strongly correlated with future risk of TKA (p < 0.001). Mean survival times were similar for those with grade II (131.7 mo) and grade III (127.6 mo); patients with grade IV, however, had a mean survival of 80.5 months, with an overall 10-year risk of TKA of 62.7%. Age, sex, side of initial TKA, and BMI were not risk factors for progression to contralateral TKA. CONCLUSION: In this cohort, the K-L grading scale was a highly significant predictor for progression of contralateral OA to TKA. These data may provide important information to patients undergoing TKA, and shed light on the natural history of contralateral OA after TKA.     

The incidence and natural history of knee osteoarthritis in the elderly,the framingham osteoarthritis study

Objective. To determine the incidence of radiographic knee osteoarthritis (OA) and symptomatic OA (symptoms plus radiographic OA), as well as the rate of progression of preexisting radiographic OA in a population-based sample of elderly persons. Methods. Framingham Osteoarthritis Study subjects who had knee radiographs and had answered questions about knee symptoms in 1983–1985 were reexamined in 1992–1993 (mean 8.1-year interval) using the same protocol. Subjects were defined as having new (incident) radiographic OA if they developed grade ≤2 OA (at least definite osteophytes or definite joint space narrowing). New symptomatic OA was present if subjects developed a combination of knee symptoms and grade ≤2 OA. Progressive OA was diagnosed when radiographs showing grade 2 disease at baseline showed grade ≤3 disease on followup. Results. Of 1,438 participants in the original study, 387 (26.9%) died prior to followup. Of the 1,051 surviving subjects, 869 (82.7%) participated in the followup study (mean ± SD age 70.8 ± 5.0 at baseline). Rates of incident disease were 1.7 times higher in women than in men (95% confidence interval [CI] 1.0–2.7), and progressive disease occurred slightly more often in women (relative risk = 1.4; 95% CI 0.8–2.5) but rates did not vary by age in this sample. Among women, approximately 2% per year developed incident radiographic disease, 1% per year developed symptomatic knee OA, and about 4% per year experienced progres- sive knee OA. Conclusion. In elderly persons, the new onset of knee OA is frequent and is more common in women than men. However, among the elederly, age may not affect new disease occurrence or progression.     

Towards classification criteria for early-stage knee osteoarthritis: A population-based study to enrich for progressors

ObjectiveTo facilitate a greater likelihood of favorable response to new disease-modifying therapies, recruitment of patients at an earlier stage of their disease into clinical trials may be an attractive strategy. Hence, there is a need to develop widely accepted classification criteria for early-stage knee osteoarthritis (OA). We have proposed a set of classification criteria for early-stage knee OA (2018 classification criteria) now being further refined. Here, we test the draft criteria for enrichment for clinical and structural progression.DesignPerformance of the 2018 classification criteria for early stage knee OA was tested using data from the Osteoarthritis Initiative (OAI). The OAI comprises data of 4796 men and women aged 45–79 years with or at risk for knee OA at baseline. Based on the 2018 classification criteria, a knee with Kellgren & Lawrence (K&L) grade of 0-I, two out of four Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales equal or less than 85, and presence of at least one of joint line tenderness or crepitus, was considered as early-stage knee OA. Knees with K&L grade 0-I that did not fulfill the 2018 criteria, were considered as controls. Logistic regression analysis was used to evaluate the predictive performance of the criteria set for structural as well as clinical progression. We further explored the discriminatory capability of criteria by including the average KOOS₄ score, and relevant clinical examination findings such as the presence of effusion and/or Heberden's nodes.ResultsWe identified 1315 (27%) knees from OAI fulfilling the 2018 early-stage knee OA classification criteria. The female to male ratio was higher in the early knee OA group compared to controls. The early-stage knee OA group were on average slightly younger and had higher body mass index vs controls (mean [SD] age: 59.2 [8.9] years vs. 60.2 [9.1] and mean [SD] BMI 28.3 [7.0] vs. 26.8 [6.0]). By applying the 2018 criteria, there was a substantial enrichment compared to controls at 48 and 96 months for both structural (OR=1.1–1.4, and AUC=0.72–0.74) and clinical progressors (OR=2.1–2.5, 95% and AUC=0.66). Expanding the clinical examination findings by including joint effusion and/or Heberden's nodes improved the enrichment for both structural and clinical progressors (OR=4.2, 95% confidence interval=3.2–5.5 and OR=3.3, 95% confidence interval=2.8–3.5, respectively). Replacing scoring of the 4 separate KOOS domains by a KOOS₄ score performed comparably.ConclusionsThe proposed 2018 early-stage knee OA classification criteria showed encouraging performance characteristics with regard to an enrichment for structural and clinical progression using longitudinal OAI data. Our results indicate that the addition of clinical findings improves the performance of previous criteria to define early-stage disease and risk for progression.     

Physical activity and risk of revision total knee arthroplasty in individuals with knee osteoarthritis: a matched case-control study

OBJECTIVE: To determine if physical activity was a risk factor for revision arthroplasty after primary total knee arthroplasty (TKA) due to osteoarthritis (OA) within the previous 15 years. METHODS: This was a matched case-control study. The cases had primary TKA followed by revision arthroplasty. Controls had primary TKA and no revision arthroplasty. Cases and controls were matched for age, sex, number of knees replaced, and date of primary TKA. Standardized telephone interviews were conducted to assess historical leisure activity, occupational activity, and instrumental activities of daily living after primary TKA in metabolic equivalent (MET)-hours per week. Conditional logistic regression was performed to identify the variables that predicted the need for revision arthroplasty. RESULTS: Seventeen female and 9 male pairs, aged 47 to 85 years, participated. Most of the reported activity was of low impact and low or moderate intensity. Cases reported a median of 44.5 (range 0 to 137) MET-hours of total historical physical activity per week compared with controls' 55.1 (range 0 to 278) MET-hours. Total historical physical activity was not associated with the risk of revision arthroplasty (OR 0.99, 95% CI 0.99-1.01). Participants with primary TKA (controls) consistently reported more MET-hours of leisure and occupational activity than those with revision arthroplasty (cases) regardless of the number of knees replaced or whether or not walking was accounted for. CONCLUSION: This study quantified and described patterns of physical activity in a population with TKA. Physical activity did not appear to be a risk factor for revision arthroplasty. Our results suggest that individuals undergoing primary TKA should be encouraged to remain active after surgery.     

The incidence of mucinous appendiceal malignancies: a population-based study

Purpose

Mucinous appendiceal tumours were described already 180 years ago, but reliable data on the incidence of these tumours are sparse. The clinical importance of these tumours is increasing since they are now identified as the most common site of origin for pseudomyxoma peritonei (PMP), which is currently recognised as a treatable condition.

Methods

Data on the incidence of mucinous appendiceal tumours were retrieved from the Eindhoven Cancer Registry, which collects data on all patients with newly diagnosed cancer in a large part of the southern Netherlands that comprises about 2.3 million inhabitants. From 1980 to 2010, all cases of primary adenocarcinomas of the appendix were included.

Results

From 1980 to 2010, a mucinous adenocarcinoma was diagnosed in 78 patients being 48 % of all cases of appendiceal adenocarcinoma diagnosed during this period (n?=?164). The incidence increased during the study period from 0.6 to 1.9 per 1,000,000 person-years for women and from 0.4 to 1.0 per 1,000,000 person-years for men.

Conclusion

The reported incidence of mucinous adenocarcinomas of the appendix shows an increasing trend. This is probably mainly explained by the increased awareness of this tumour and its relation with PMP, and better registration of this specific diagnosis.     

The impact of hip and knee osteoarthritis on the subsequent risk of incident diabetes: a population-based cohort study

Aims/hypothesis

This study examined the relationship between hip/knee osteoarthritis and incident diabetes. We hypothesised that hip/knee osteoarthritis would be independently related to an increased risk of incident diabetes and that this relationship would be due, at least in part, to walking difficulty. We also hypothesised a stronger relationship with incident diabetes for knee than hip osteoarthritis because of the higher prevalence in the former of obesity/the metabolic syndrome.

Methods

A population cohort aged ≥55 years recruited from 1996 to 1998 was followed through provincial health administrative data to 2014. Participants with baseline diabetes were excluded. Hip/knee osteoarthritis was defined as swelling, pain or stiffness in any joint lasting 6 weeks in the past 3 months and indication on a joint homunculus that a hip/knee was ‘troublesome’. Walking limitation was defined as self-reported difficulty standing or walking in the last 3 months (yes/no). Using Cox regressions, we examined the relationship of baseline hip/knee osteoarthritis with incident diabetes as defined from health administrative data, controlling for age, sex, BMI, income, prior hypertension, cardiovascular disease and primary care exposure. We tested whether the observed effect was mediated through walking limitation.

Results

In total, 16,362 participants were included: median age 68 years and 61% female. Of these, 1637 (10%) individuals met the criteria for hip osteoarthritis, 2431 (15%) for knee osteoarthritis and 3908 (24%) for walking limitation. Over a median follow-up of 13.5 years (interquartile range 7.3–17.8), 3539 individuals (22%) developed diabetes. Controlling for confounders, a significant relationship was observed between number of hip/knee joints with osteoarthritis and incident diabetes: HR for two vs no osteoarthritic hips 1.25 (95% CI 1.08, 1.44); HR for two vs no osteoarthritic knees 1.16 (95% CI 1.04, 1.29). From 37% to 46% of this relationship was explained by baseline walking limitation.

Conclusions/interpretation

In a large population cohort aged ≥55 years who were free of diabetes at baseline, and controlling for confounders, the presence and burden of hip/knee osteoarthritis was a significant independent predictor of incident diabetes. This association was partially explained by walking limitation. Increased attention to osteoarthritis and osteoarthritis-related functional limitations has the potential to reduce diabetes risk.

     

High prevalence of patellofemoral osteoarthritis in China: a multi-center population-based osteoarthritis study

Clinical Rheumatology - To describe the prevalence and risk factors of patellofemoral osteoarthritis (PFOA) among Chinese residents. A multi-center population-based osteoarthritis study was...     

The high prevalence of knee osteoarthritis in a rural Chinese population: The Wuchuan osteoarthritis study

Objective

To estimate the prevalence of radiographic and symptomatic knee osteoarthritis (OA) in a remote rural region of northern China, and compare them with those reported in Beijing and with data from the Framingham (Massachusetts) cohort.

Methods

A population‐based cross‐sectional survey was conducted among 1,030 residents of Wuchuan County, Inner Mongolia, age ≥50 years. Survey participants, mostly farmers reporting heavy physical occupational activity, completed an interviewer‐based questionnaire, and bilateral weight‐bearing posteroanterior semiflexed knee radiographs were obtained.

Results

Whereas the overall prevalence of radiographic knee OA was similar to that demonstrated in the Beijing OA study, men in Wuchuan had approximately double the prevalence of severe radiographic knee OA (prevalence ratio [PR] 2.5, 95% confidence interval [95% CI] 1.6–3.8) and symptomatic knee OA (PR 1.9, 95% CI 1.3–2.9). Women in Wuchuan also had a higher prevalence of both severe radiographic (PR 1.4, 95% CI 1.0–2.0) and symptomatic knee OA (PR 1.6, 95% CI 1.2–2.1) compared with their Beijing counterparts. The prevalence of bilateral OA and lateral compartment disease were 2–3 times higher in both Chinese cohorts compared with estimates from the Framingham OA study.

Conclusion

The prevalence of symptomatic knee OA in rural areas of China is much higher than reported from urban regions of China or in the Framingham cohort. The higher representation of bilateral and lateral compartment disease in China suggests a unique phenotype to OA. These findings will be useful for guiding the distribution of future health care resources and preventive strategies. This article was published online on April 29, 2009. The incorrect figure was published for Figure 1. This notice is included in the online and print versions to indicate that both have been corrected.     

Valgus malalignment is a risk factor for lateral knee osteoarthritis incidence and progression: Findings from the multicenter osteoarthritis study and the osteoarthritis initiative

Objective

To study the effect of valgus malalignment on knee osteoarthritis (OA) incidence and progression.

Methods

We measured the mechanical axis from long limb radiographs from the Multicenter Osteoarthritis Study (MOST) and the Osteoarthritis Initiative (OAI) to define limbs with valgus malalignment (mechanical axis of ≥1.1° valgus) and examined the effect of valgus alignment versus neutral alignment (neither varus nor valgus) on OA structural outcomes. Posteroanterior radiographs and knee magnetic resonance (MR) images were obtained at the time of the long limb radiograph and at followup examinations. Lateral progression was defined as an increase in joint space narrowing (on a semiquantitative scale) in knees with OA, and incidence was defined as new lateral narrowing in knees without radiographic OA. We defined lateral cartilage damage and progressive meniscal damage as increases in cartilage or meniscus scores at followup on the Whole‐Organ Magnetic Resonance Imaging Score scale (for the MOST) or the Boston Leeds Osteoarthritis Knee Score scale (for the OAI). We used logistic regression with adjustment for age, sex, body mass index, and Kellgren/Lawrence grade, as well as generalized estimating equations, to evaluate the effect of valgus alignment versus neutral alignment on disease outcomes. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs).

Results

We studied 5,053 knees (881 valgus) of subjects in the MOST cohort and 5,953 knees (1,358 valgus) of subjects in the OAI cohort. In both studies, all strata of valgus malalignment, including 1.1° to 3° valgus, were associated with an increased risk of lateral disease progression. In knees without radiographic OA, valgus alignment >3° was associated with incidence (e.g., in the MOST, adjusted OR 2.5 [95% CI 1.0–5.9]). Valgus alignment >3° was also associated with cartilage damage on MR imaging in knees without OA (e.g., in the OAI, adjusted OR 5.9 [95% CI 1.1–30.3]).We found a strong relationship of valgus malalignment with progressive lateral meniscal damage.

Conclusion

Valgus malalignment increases the risk of knee OA radiographic progression and incidence as well as the risk of lateral cartilage damage. It may cause these effects, in part, by increasing the risk of meniscal damage.

     

Persons with varicose veins have a high subsequent incidence of arterial disease: a population-based study in Tampere, Finland

The aim of this population research was to find out the risk of arterial disease (defined as angina pectoris, myocardial infarction, peripheral occlusive arterial disease, and cerebrovascular disease) and hypertension in persons with varicose veins. A 5-year follow-up study was conducted in Tampere, Finland. A validated questionnaire was used in 3 middle-aged cohorts (40, 50, and 60 year olds) in a general population of 6,874. In the follow-up study, 71% (n = 4,903) replied. The incidence of arterial disease and hypertension was studied in those with varicose veins and those without at the entry to the study. During the follow-up, new arterial disease occurred significantly more often in individuals with varicose veins. The incidence odds ratio was 2.0 (95% confidence interval, 1.5-2.7; n = 3,032), but the incidence odds ratio of new hypertension was 1.0 (95% confidence interval, 0.8-1.3; n = 2,915). Varicose veins are a risk indicator of arterial disease but not of hypertension. Varicose veins likely do not cause arterial disease, but they may have common causes that, however, are not related with hypertension.     

Epidemiology,risk of malignancy and patient survival in primary sclerosing cholangitis: a population-based study in Finland

Abstract

Background: There are only a few and mostly small population-based epidemiological studies of primary sclerosing cholangitis (PSC).

Objective: We aimed to estimate prevalence and incidence rates of PSC, and survival and malignancy risk for PSC patients in a large population-based study.

Methods: We retrieved 632 PSC patients from 1990 to 2015 in the Hospital District of Helsinki and Uusimaa (HUS), comprising 29% of the Finnish population. Mortality information of the PSC patients was obtained from the national Population Registry, malignancy information from the Finnish Cancer Registry and the causes of death from the Statistics Finland. Standardized incidence ratio and standardized mortality ratio (SMR) were calculated for predefined malignancy types.

Results: The crude incidence of PSC in the HUS area was 1.58/100,000 person-years, and the point prevalence in 2015 was 31.7/100,000 inhabitants. The mean time from diagnosis to death was 21.9 years. The risk for any malignancy was three-fold and the risk for colorectal carcinoma was five-fold when comparing with the general population. During the first year after diagnosis of PSC, the risk for cholangiocarcinoma is 900-fold compared to the general population and after that 150-fold. SMR for all malignant neoplasms was 5.9 (95% CI 4.2–8.1).

Conclusion: We found that the incidence of PSC in the HUS area in Finland is similar or higher than previously reported from other countries. The prevalence is markedly higher than reported elsewhere, probably due to the active search of the disease, suggesting that the disease is underdiagnosed.     

Arthroscopic cartilage regeneration facilitating procedure: A decompressing arthroplasty for knee osteoarthritis

The effectiveness of arthroscopic treatment for knee osteoarthritis (OA) has always been a subject of debate. This study presents an innovative concept for the arthroscopic management of knee OA and investigates its clinical outcomes. An arthroscopic cartilage regeneration facilitating procedure (ACRFP) was performed on 693 knees of 411 patients with knee OA, with a mean age of 60 years (34–90 years), to eliminate the medial abrasion phenomenon (MAP) and decompress the patellofemoral joints. The Knee Society Score (KSS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were used to determine the subjective outcome. Roentgenographic changes in all cases and magnetic resonance imaging (MRI) variations in 20 randomly selected cases were evaluated for objective outcomes. We evaluated 634 knees in 369 patients (93.7%) with more than 3 years of follow-up (mean, 40 months; SD, 9) and found that the overall subjective satisfaction rate was 91.1%. Scores for KSS and all KOOS subscales improved statistically. Reversal of cartilage degeneration was observed in 80.1% of the entire series (radiographic outcome study) and 72.2% of the 18 randomly selected cases (1-year MRI outcome study). We found significant association between gender and OA severity, with regards to the subjective outcomes. Age, body mass index, pre-operative hyaluronic acid injection, OA severity, and type and severity of the medial plica were found to be important predictors of radiographic outcomes. An analysis of failed cases reaffirmed the need for early ACRFP and skilled post-operative care. ACRFP is an effective treatment for knee OA. It can benefit most patients and modify their degeneration processes if performed in time. However, further investigations are needed to confirm our concept of treatment.     

Extreme variations in racial rates of total hip arthroplasty for primary coxarthrosis: a population-based study in San Francisco.

OBJECTIVES--To compare the incidence of all total hip arthroplasty, and total hip arthroplasty for primary coxarthrosis, among the Asian, black, Hispanic, and white populations living in one locale. METHODS--We identified all San Francisco residents who underwent total hip replacements (THR) in the 17 hospitals for adults within or near San Francisco County during a five year period. Preoperative pelvic radiographs were read without prior knowledge of the gender or race of the subject, to diagnose the specific hip diseases. Age standardised THR incidence by race and gender was determined, as was the comparative THR incidence for specific diagnosis (primary and secondary osteoarthritis). RESULTS--The greatest annual rate of total hip replacement occurred in white women (97 per 100,000 population), followed by white men, black women, black men, Hispanic women, and Hispanic men. The smallest numbers were found in Asians, whose THR rate was 10% that of whites. A primary coxarthrosis diagnosis was greatest among white subjects (66%), followed by black subjects (54%), Hispanics (53%), and Asians (28%). Age standardised THR rates for primary coxarthrosis per 100,000 population were likewise greatest among whites (43.0) and least among Asians (1.3 for Chinese). Mean age of patients undergoing THR for primary coxarthrosis was 70 years for white subjects and almost a decade younger in all other groups. CONCLUSIONS--THR rates are much lower for Asians, Hispanics, and black subjects than for the white population living in San Francisco. The low rates of total hip arthroplasty in the non-white groups was related to the much lower incidence of THR for primary coxarthrosis among non-whites than among whites. The racial distribution of primary coxarthrosis among patients who underwent THR is consistent with distribution patterns reported internationally.     

Saline washout for knee osteoarthritis: Results of a controlled study

Summary Twenty patients with persistent symptoms due to osteoarthritis of the knee were randomly allocated to a saline washout or control group. Both groups showed improvement. Knee washout conferred no more benefit than intra-articular saline injection.