Knee replacement surgery for osteoarthritis: effectiveness, practice variations, indications and possible determinants of utilization

Radiomics analysis of patellofemoral joint improves knee replacement risk prediction: Data from the Multicenter Osteoarthritis Study (MOST)

Objective

Knee replacement (KR) is the last-resort treatment for knee osteoarthritis. Although radiographic evidence of tibiofemoral joint has been widely adopted for prognostication, patellofemoral joint has gained little attention and may hold additional value for further improvements. We aimed to quantitatively analyse patellofemoral joint through radiomics analysis of lateral view radiographs for improved KR risk prediction.

Design

From the Multicenter Osteoarthritis Study dataset, we retrospectively retrieved the initial-visit lateral left knee radiographs of 2943 patients aged 50 to 79. They were split into training and test cohorts at a 2:1 ratio. A comprehensive set of radiomic features were extracted within the best-performing subregion of patellofemoral joint and combined into a radiomics score (RadScore). A KR risk score, derived from Kellgren-Lawrence grade (KLG) of tibiofemoral joint and RadScore of patellofemoral joint, was developed by multivariate Cox regression and assessed using time-dependent area under receiver operating characteristic curve (AUC).

Results

While patellofemoral osteoarthritis (PFOA) was insignificant during multivariate analysis, RadScore was identified as an independent risk factor (multivariate Cox p-value < 0.001) for KR. The subgroup analysis revealed that RadScore was particularly effective in predicting rapid progressor (KR occurrence before 30 months) among early- (KLG < 2) and mid-stage (KLG ​= ​2) patients. Combining two joints radiographic information, the AUC reached 0.89/0.87 for predicting 60-month KR occurrence.

Conclusions

The RadScore of the patellofemoral joint on lateral radiographs emerges as an independent prognostic factor for improving KR prognosis prediction. The KR risk score could be instrumental in managing progressive knee osteoarthritis interventions.

Attenuation correction for PET/MRI to measure tracer activity surrounding total knee arthroplasty

Background

Positron emission tomography (PET) in combination with magnetic resonance imaging (MRI) could allow inflammatory complications near total knee arthroplasty (TKA) to be studied early in their development. However, attenuation of the PET signal by the metal TKA implants imparts substantial error into measurements of tracer activity, and conventional MR-based attenuation correction (AC) methods have large signal voids in the vicinity of metal implants.

Purpose

To evaluate a segmentation-based AC approach to measure tracer uptake from PET/MRI scans near TKA implants.

Methods

A TKA implant (Triathlon, Stryker, Mahwah, USA) was implanted into a cadaver. Four vials were filled with [¹⁸F]fluorodeoxyglucose with known activity concentration (4.68 MBq total, 0.76 MBq/mL) and inserted into the knee. Images of the knee were acquired using a 3T PET/MRI system (Biograph mMR, Siemens Healthcare, Erlangen, Germany). Models of the implant components were registered to the MR data using rigid-body transformations and the other tissue classes were manually segmented. These segments were used to create the segmentation-based map and complete the AC. Percentage error of the resulting measured activities was calculated by comparing the measured and known amounts of activity in each vial.

Results

The original AC resulted in a percentage error of 64.1% from the known total activity. Errors in the individual vial activities ranged from 40.2 to 82.7%. Using the new segmentation-based AC, the percentage error of the total activity decreased to 3.55%. Errors in the individual vials were less than 15%.

Conclusions

The segmentation-based AC technique dramatically reduced the error in activity measurements that result from PET signal attenuation by the metal TKA implant. This approach may be useful to enhance the reliability of PET/MRI measurements for numerous applications.

Quality of life assessment after total knee arthroplasty in patients with Parkinson's disease

Background

The number of Parkinson’s patients (PD) undergoing total knee arthroplasty (TKA) is increasing. The purpose of the study was to characterize quality of life (QOL) outcomes for patients with coexisting PD and knee osteoarthritis (KOA) following TKA.

Methods

Patients with coexisting PD and KOA undergoing TKA between June 2014 and June 2020 were included. These patients were matched to controls with KOA alone by age, gender, basic social background information and Knee society score (KSS). The primary measure was to assess the QOL by the absolute changes in the EuroQOL5-Dimensions (EQ-5D), Pain and Disability Questionnaire (PDQ), and Patient Health Questionnaire-9(PHQ-9) at the last follow-up (LFU). Secondary measures were changes in QOL that exceeded the minimum clinically important difference value (MCID). Data on the health status and QOL of all patients were collected. Simple and multivariate regression analysis was used to evaluate the impact of PD on their QOL.

Results

Twelve KOA patients with PD were compared with 48 controls. Control patients experienced QOL improvement across all three measures:EQ-5D index (0.545–0.717, P < 0.01), PDQ (81.1–52.3, P < 0.01) and PHQ-9(8.22–5.91, P < 0.01) were significantly improved at the LFU; while in patients with PD, only PDQ (91.0–81.4, P = 0.03) slightly improved. There were significant differences in the improvement of QOL between PD patients and the control group through EQ-5D (0.531 vs.0.717, P < 0.01) and PDQ (81.4vs.52.3, P < 0.01) at the LFU.

Conclusion

TKA has no benefit of QOL beyond a slight improvement in pain-related disability in the KOA patients with PD.

The use of mobile bearing TKA in valgus deformities - A clinical study

BACKGROUND

The number of patients presenting valgus deformities undergoing total knee arthroplasty (TKA) represents approximately 10% of the total number of TKAs performed: the presence of valgus deformity requires the implant to have proper alignment, stability and balance to achieve successful clinical outcomes, especially for knees with high coronal deformities, but these have proven to be difficult goals to achieve and therefore the use of constrained prostheses is often recommended for these cases. However, even though the use of unconstrained mobile bearing for severe knee deformities is rare, it has been shown to give successful outcomes and therefore the aim of this study is to evaluate whether this surgical technique can achieve satisfactory clinical results and correct alignment, as well as good patient satisfaction.

METHODS

This study presents the results of 69 TKA performed with cemented mobile bearing implants by a single surgeon on knee affected by valgus deformities. Asymmetric inserts were adopted for all the implants and an alignment surgical tool, dedicated for valgus patients, was used during the operation. Angles of valgus, WOMAC surveys and Numeric Rating Scale for pain were recorded to evaluate the results of the operations.

RESULTS

A total of 67 pre-op WOMAC questionnaire surveys were collected, with the mean result of this evaluation being 15.9 points. The Numeric Rating Scale for pain had an average of 2.2 for 68 tests. The deformities were corrected from a mean total preoperative valgus angle of 12.5° to a postoperative valgus deformity average of 0.6°. During follow-up, only one patient had serious complications due to the rupture of the extensor apparatus following a domestic accident involving falling. Further 10 patients have mild complications related to injuries such as pain of varying intensity, burning, or swelling of the knee. The level of satisfaction from 0 to 10 (0 not at all satisfied and 10 perfectly satisfied) had an average score of 7.7.

CONCLUSIONS

The surgical approach presented, involving a less constrained model if compared to the ones usually chosen, allowed to achieve correct alignment and high patient satisfaction using mobile bearing implants on valgus knee deformities; further patient follow-up will be performed to evaluate long-term outcomes, but the results achieved already represent a significative finding.

Preoperative Factors Affecting Patient-reported Outcome Measures for Total Knee Arthroplasty

Objectives:

The aim of this study was to investigate the preoperative factors affecting health-related quality of life (HRQOL) at 3 and 12 months after total knee arthroplasty (TKA).

Methods:

In total, 156 patients who underwent unilateral TKA for knee osteoarthritis were included in the study. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used as a measure of HRQOL before surgery and 3 and 12 months post-TKA. The Modified Gait Efficacy Scale (mGES) score, tibiofemoral angle, rest pain, walking pain, knee joint range of motion, knee joint extensor strength, and walking speed were recorded preoperatively. Pearson’s correlation coefficient and the correlation ratio were used to calculate the correlation between KOOS and preoperative factors at 3 and 12 months post-TKA. Multiple regression analysis was performed using the stepwise method with the five postoperative KOOS subscales as dependent variables and the other preoperative factors as independent variables.

Results:

Preoperative mGES scores were significantly correlated with KOOS Activities of Daily Living, Sport/Rec, and QOL subscores at 3 months post-TKA and with all five KOOS subscales at 12 months post-TKA. Multiple regression analysis identified mGES as an influencing factor for all KOOS subscales except Pain at 3 months post-TKA and all KOOS subscales except Symptoms at 12 months post-TKA.

Conclusions:

Preoperative walking self-efficacy influenced HRQOL at 3 and 12 months post-TKA. Psychological factors such as self-efficacy should be considered when predicting postoperative outcomes.

How Are Neighborhood Characteristics Associated With Mental and Physical Functioning Among Older Adults With Radiographic Knee Osteoarthritis?

OBJECTIVE

To examine how neighborhood characteristics are associated with health outcomes among older adults with osteoarthritis.

METHODS

In multilevel, cross-sectional, and longitudinal analyses we examined whether 4 neighborhood characteristics were associated with depressive symptoms and reported knee impact scores, and whether the neighborhood characteristics interacted with race/ethnicity among older adults with radiographic knee osteoarthritis (n = 656 for cross-sectional analyses and n = 434 for longitudinal analyses). The data came from the Johnston County Osteoarthritis Project, a prospective cohort study in North Carolina designed to examine risk factors for osteoarthritis.

RESULTS

Although few longitudinal associations were found, cross-sectional results suggested that greater perceived neighborhood social cohesion (B = -0.04, P < 0.001) and perceived neighborhood resources for physical activity and walking (B = -0.03, P < 0.001) were associated with fewer depressive symptoms, and that greater perceived neighborhood resources for physical activity and walking were associated with higher (better) knee impact scores (B = 0.48, P = 0.008). We also observed 2 significant interactions among neighborhood characteristics and race/ethnicity related to depressive symptoms (P < 0.01); for African American adults, greater perceived neighborhood resources for physical activity and walking were associated with fewer depressive symptoms (B = -0.03, P < 0.001), but for White adults, greater perceived neighborhood safety was associated with fewer depressive symptoms (B = -0.04, P = 0.003).

CONCLUSION

In a sample of older adults with radiographic knee osteoarthritis, neighborhood context mattered, but in nuanced ways. Interventions aiming to improve mental and physical functioning of older adults with knee osteoarthritis can look to this study as evidence for the importance of neighborhood characteristics.

The implications of an aging population and increased obesity for knee arthroplasty rates in Sweden: a register-based study

Background and purpose - Total knee arthroplasty (TKA) has increased substantially in Sweden. We quantified the relative risk for TKA in the Swedish population for different BMI categories and age groups to investigate whether the continued increase in TKA is attributable to increased prevalence of obesity and elderly people in the population, and to put forward model predictions for coming needs for TKA. Patients and methods - We used the Swedish Nationwide Health Survey (SNHS) and the Swedish Knee Arthroplasty Register (SKAR) 2009-2015 to calculate the relative risk (RR) of TKA by age (middle-aged 45-64 years and elderly 65-84 years) and BMI (BMI 18.5-24.9 normal weight; BMI 25.0-29.9 overweight; BMI > 30 obese). The RR for TKA was applied to the demographic forecasts for the Swedish population as a forecasting model. Results - Population size increased 5.2% from 2009 to 2015 to 40,000 middle-aged and 250,000 elderly, and the prevalence of obesity increased from 16% to 18% in these 2 age categories. Compared with those of normal weight, the RR for TKA was 2.7 (95% CI 2.5-3.0) higher for the overweight and 7.3 (6.7-8.0) higher for the obese, aged 45-64. The corresponding figures for individuals aged 65-84 were 2.1 (2.0-2.2) and 4.0 (3.8-4.3) higher, respectively. The changes in the prevalence of obesity and an increase in the elderly population accounted for an estimated increase of 1,700 TKAs over the 7 years. Interpretation - The increase in obesity frequency and the rise in the population of middle-aged and elderly may, to some extent, explain the rise in TKA utilization in Sweden.

Knee OA cost comparison for hyaluronic acid and knee arthroplasty

BACKGROUND

Limiting treatment to those recommended by the American Academy of Orthopaedic Surgeon Clinical Practice Guidelines has been suggested to decrease costs by 45% in the year prior to total knee arthroplasty, but this only focuses on expenditures leading up to, but not including, the surgery and not the entire episode of care. We evaluated the treatment costs following knee osteoarthritis (OA) diagnosis and determined whether these are different for patients who use intra-articular hyaluronic acid (HA) and/or knee arthroplasty.

METHODS

Claims data from a large commercial database containing de-identified data of more than 100 million patients with continuous coverage from 2012 to 2016 was used to evaluate the cumulative cost of care for over 2 million de-identified members with knee OA over a 4.5-year period between 2011 and 2015. Median cumulative costs were then stratified for patients with or without HA and/or knee arthroplasty.

RESULTS

Knee OA treatment costs for 1,567,024 patients over the 4.5-year period was $6.60 billion (mean $4210/patient) as calculated by the authors. HA and knee arthroplasty accounted for 3.0 and 61.5% of the overall costs, respectively. For patients who underwent knee arthroplasty, a spike in median costs occurred sooner for patients without HA use (around the 5- to 6-month time point) compared to patients treated with HA (around the 16- to 17-month time point).

CONCLUSIONS

Non-arthroplasty therapies, as calculated by the authors, accounted for about one third of the costs in treating knee OA in our cohort. Although some have theorized that limiting the use of HA may reduce the costs of OA treatment, HA only comprised a small fraction (3%) of the overall costs. Among patients who underwent knee arthroplasty, those treated with HA experienced elevated costs from the surgery later than those without HA, which reflects their longer time to undergoing knee arthroplasty. The ability to delay or avoid knee arthroplasty altogether can have a substantial impact on the cost to the healthcare system.

Access to hip and knee replacement surgery in patients with chronic diseases according to patient-reported pain and functional status

BACKGROUND

An increasing number of patients undergoing hip or knee replacement have chronic diseases. It has been suggested that the presence of chronic diseases may affect access to this type of surgery in the English National Health Service (NHS). We examined the access to hip and knee replacement surgery in patients with and without chronic diseases according to preoperative patient-reported pain, functional status and symptom duration.

METHODS

We analysed data of 640,832 patients who had hip or knee surgery between 2009 and 2016 in England. Multivariable regression was used to estimate the impact of 11 chronic diseases on severity of joint problems as measured on a scale from 0 to 48 by Oxford Hip (OHS) and Knee Scores (OKS) just before surgery and on likelihood of long-standing joint problems (> 5 years pre-operatively).

RESULTS

Patients with chronic diseases reported more severe joint problems than patients without (OHS differences ranged from 1.1 [95% CI 0.93, 1.2] to 2.5 [95% CI 2.3, 2.7] and OKS differences from 0.5 [95% CI 0.3, 0.7] to 2.6 [95% CI 2.4, 2.7] for the 11 chronic diseases) but the differences remain small. When analysed separately, patients with chronic diseases reported both more severe pain and poorer functional status. Six chronic diseases in hip patients and two in knee patients increased the likelihood that they had long-standing joint problems. The severity of joint problems just before surgery increased with the number of chronic diseases (OHS differences; one chronic disease (1.5 [95% CI 1.4, 1.5]) to four or more (5.8 [95% CI 5.6, 6.0])).

CONCLUSIONS

Patients with chronic diseases reported more severe joint problems immediately before hip or knee replacement surgery suggesting they have hip or knee replacement later in the course of their joint disease.

Return to Sport Activity in the Elderly Patients after Unicompartmental Knee Arthroplasty: A Systematic Review and Meta-Analysis

In patients with knee osteoarthritis, when only medial or lateral compartment of the knee is involved, unicompartimental knee arthroplasty (UKA) is a reliable option for addressing the symptoms and restore function. The main aim of the present review is to systematically collect the available evidence concerning the return to sport activity in the elderly patients after UKA. An electronic search was carried out on the following databases; Pubmed-Medline, Cochrane central, and Scopus, searching for randomized controlled trials, prospective cohort studies, retrospective case-control studies, and case series. Data concerning the evaluation of the return to sport (RTS) and of functional outcomes in the elderly patients after UKA surgery. MINORS score was used to assess the risk of methodological biases. Odds ratios and raw proportions were used to report the pooled effect of UKA on the return to sport in comparative and non-comparative studies, respectively. Same level RTS in elderly patients was of 86% (pooled return proportion 0.86, 95%CI 0.78, 0.94), showing also better relative RTS and time to RTS of patients undergoing UKA, in comparison to those undergoing TKA. Sport-specific RTS showed that higher return rates were observed for low-impact sports, whereas high-impact sports prevented a full return to activities. UKA is a valid and reliable option for elderly patients to satisfactorily resume their sport practice, especially for low impact activities. The rate of return to sports following UKA is higher than TKA.

Acupuncture and moxibustion for pain relief and quality of life improvement in patients with knee osteoarthritis: A protocol for systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis is to assess the efficacy of acupuncture and moxibustion in pain relief and quality of life improvement of knee osteoarthritis (KOA) patients.

METHODS

The following databases will be searched: MEDLINE, EMBASE, the Cochrane Library, Web of Science, Chinese Biomedical Literature Database, Chinese Nation Knowledge Infrastructure, Wanfang Database, the Chongqing VIP from inception to May 1, 2020. All randomized controlled trials (RCTs) used acupuncture or moxibustion to relieve pain and improve quality of life (QoL) among KOA patients will be included. Study selection, data extraction, quality assessment and assessment of risk bias will be performed by 2 reviewers independently. Data synthesis will be performed using Review Manager V5.3 software. A meta-analysis will be performed when there is sufficient available data.

PROSPERO REGISTRATION NUMBER

CRD42020169724.

The cardiovascular risk of celecoxib for knee osteoarthritis: A protocol for systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis is to assess the cardiovascular (CV) risk of celecoxib on knee osteoarthritis (KOA) patients compared with the risk in those prescribed other non-selective non-steroidal anti-inflammatory drugs (NSAIDs), no intervention or placebo-controlled patients.

METHODS

The following databases will be searched: MEDLINE, EMBASE, the Cochrane Library, Web of Science, Chinese Biomedical Literature Database, Chinese Nation Knowledge Infrastructure, Wanfang Database, and the Chongqing VIP from inception to April 1, 2020. All randomized controlled trials (RCTs) of celecoxib that presented data on serious cardiovascular events among KOA patients will be included. Study selection, data extraction, quality assessment, and assessment of risk bias will be performed by 2 reviewers independently. Odds ratios and correlative 95% confidence intervals will be calculated to present the association between the celecoxib and CV risk using Review Manager version 5.3 when there is sufficient available data.

ETHICS AND DISSEMINATION

This review does not require ethical approval. The results of this review may be published in a peer-reviewed journal or disseminated at relevant conferences.

PROSPERO REGISTRATION NUMBER

CRD42020166721.

Influence of Patellar Tilt Angle in Merchant View on Postoperative Range of Motion in Posterior Cruciate Ligament-Substituting Fixed-Bearing Total Knee Arthroplasty

Background

We investigated whether the patellar tilt angle influences the maximum knee flexion after total knee arthroplasty (TKA) performed by using a posterior cruciate ligament-substituting (PS) fixed-bearing prosthesis in patients with relatively loose or tight flexion gap.

Methods

In this prospective cohort study, we followed up 169 patients for at least 2 years after TKA using PS fixed-bearing prosthesis. The patients were divided into two groups according to the flexion gap value-calculated by subtracting the thickness of the final bearing from the flexion gap measured intraoperatively under 200-cN·m force after patellar reduction and insertion of the final femoral and tibial components-into a relatively tight group (group T; 3-6.5 mm) and a relatively loose group (group L; 7-11 mm). Patellar tilt angles and maximum non-weight-bearing active knee flexion angles were assessed postoperatively. Group T was further divided into subgroup Tn if the patellar tilt angle was < 5° and subgroup Tw if the angle was ≥ 5°. Pearson correlation test was used for the correlation analysis of the flexion gap, patellar tilt angle, and postoperative flexion range.

Results

The mean postoperative flexion was 137.3° in group T and 137.5° in group L. The mean patellar tilt angle was 6.5° in group T and 6.9° in group L. In group T, a strong negative correlation (r = -0.78, p < 0.05) was observed between the patellar tilt and postoperative flexion range. However, further analysis revealed that only the subgroup Tw showed a strong negative correlation (r = -0.76, p < 0.05). Significant correlations were not found in the subgroup Tn and group L.

Conclusions

In TKA where a relatively tight flexion gap (≤ 6.5 mm) is created because of concerns about postoperative flexion instability due to a loose flexion gap, the patellar tilt angle should be < 5° for maximal postoperative knee flexion.

Early return to sport post maxillofacial fracture injury in the professional athlete: A systematic review

INTRODUCTION

To summarize the current literature on return to sport times post-maxillofacial fracture injury in the professional athlete.

MATERIALS AND METHODS

A literature search on six databases for articles relating to maxillofacial fractures, professional athletes, and return to sport times. Study design, clinical data, and author recommendations were analysed.

RESULTS

17 studies were retrieved. One prospective study returned 17 athletes to competitive rugby union and soccer at 3 weeks post injury without complication. Two large retrospective studies (n = 278) returned patients to sport at approximately 7 weeks without complication. 64% (n = 7) of patients from case based studies returned to sport at 3-14 days, 4 of which utilized protective facemasks. Athletes generally returned to competition earlier for lower grade (3-10 days) compared to higher grade contact sport (21 days at least). 2 articles recommended a 3 months recovery period for combat sports. 8 articles supported the utility of protective facemasks.

CONCLUSION

Early return to sport (<6 weeks) in the professional athlete post maxillofacial fracture injury is achievable. The optimal clinical approach may be to grade the sport according to its impact forces, discuss an early return with reference to the available literature, the potential utility of facemasks, risks of refracture and its operative implications.

Outcomes of Arthroscopic Posterior Medial Meniscus Root Repair: Association With Body Mass Index

INTRODUCTION

The purpose of this study was to assess the association of outcomes from posterior medial meniscus root repairs with patient age, sex, and body mass index (BMI).

METHODS

Patients who underwent arthroscopic posterior medial meniscus root repair completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) and reported subsequent surgeries. The association of patient factors with subsequent surgery and clinical osteoarthritis (OA) based on the KOOS score was evaluated.

RESULTS

Minimum 2-year follow-up was available on 22/25 patients (88%). Two patients (9.1%) had subsequent surgeries, and 10 (45.5%) met the KOOS criteria for OA. A BMI over 35 kg/m was associated with repeat surgery (25% versus 0%; P = 0.049) and clinical OA (75% versus 28.6%; P = 0.035).

CONCLUSION

Although arthroscopic repair of posterior medial root tears has good clinical outcomes and a low rate of subsequent surgery, an elevated BMI level is associated with worse clinical outcomes and a higher rate of subsequent surgery.

Influence of early mobilization program on pain, self-reported and performance based functional measures following total knee replacement

BACKGROUND

Total knee replacement (TKR) is an optimal treatment for persons with severe knee joint pain and disability, who were unsuccessful with conservative management. Early mobilization can be defined as moving out of bed and/or walking quickly after the surgery for reducing the risks allied with bed rest. There is a paucity of studies on effects of early mobilization on a performance-based measure of timed up and go test (TUG), six-minute walk test (SMWT) and a self-reported disease-specific measure of a knee injury and Osteoarthritis outcome score (KOOS) following TKR.

METHODS

A prospective pre-post-trial was conducted at Manipal Hospital, Bangalore, India. Participants underwent early (POD '0') mobilization on the same postoperative day within 7 h post-TKR surgery. Outcome measures were recorded by an independent blinded observer. The statistical significance level was set at 'p' value < 0.05. The difference between pre-operative and post-operative outcome measure at 1 month and 3 months post-intervention were analyzed using repeated measures of ANOVA.

RESULTS

The study included a total of 78 participants (59 Females; 19 Males) and the mean age of the included participants was 64.1 ± 7 years. Amongst, 78 participants, 53 underwent unilateral TKR, 25 underwent bilateral TKR. There were three dropouts in the study due to post-operative complications. Significant improvements from pre-operative to one month were observed following POD '0' mobilization on NPRS (7.35 ± 1.2 to 4.3 ± 1.7), SMWT (169 ± 70 to 236.7 ± 80.7). KOOS subscales of pain, symptom, and quality of life showed significant changes at one month and 3 months. TUG, Knee strength, Knee ROM and KOOS ADL subscale shown improvements only at 3 months post-intervention.

CONCLUSION

Our study findings suggest that POD '0' (early) mobilization can result in reduced pain and an increase in walking speed at 1 month. Significant changes were observed in pain, Knee strength, Knee ROM, TUG, SMWT and KOOS subscales at 3 months following total knee replacement.

Interplay between sympathetic nervous system and inflammation in aseptic loosening of hip joint replacement

Inflammation is a common symptom in joint disorders such as rheumatoid arthritis, osteoarthritis (OA) and implant aseptic loosening (AL). The sympathetic nervous system is well known to play a critical role in regulating inflammatory conditions, and imbalanced sympathetic activity has been observed in rheumatoid arthritis. In AL it is not clear whether the sympathetic nervous system is altered. In this study we evaluated the systemic and local profile of neuroimmune molecules involved in the interplay between the sympathetic nervous system and the periprosthetic inflammation in hip AL. Our results showed that periprosthetic inflammation does not trigger a systemic response of the sympathetic nervous system, but is mirrored rather by the impairment of the sympathetic activity locally in the hip joint. Moreover, macrophages were identified as key players in the local regulation of inflammation by the sympathetic nervous system in a process that is implant debris-dependent and entails the reduction of both adrenergic and Neuropetide Y (NPY)-ergic activity. Additionally, our results showed a downregulation of semaphorin 3A (SEMA3A) that may be part of the mechanism sustaining the periprosthetic inflammation. Overall, the local sympathetic nervous system emerges as a putative target to mitigate the inflammatory response to debris release and extending the lifespan of orthopedic implants.

Comorbidities and the referral pathway to access joint replacement surgery: an exploratory qualitative study

Background

Variation in access to joint replacement surgery has been widely reported but less attention has been given to the impact of comorbidities on the patient journey to joint replacement surgery. There is a lack of consensus amongst healthcare professionals and commissioners about how patients with comorbidities should be referred or selected for joint replacement surgery. It is therefore important to understand the views of healthcare professionals on the management, referral and selection of patients with comorbidities for joint replacement surgery.

Methods

An exploratory qualitative study involving semi-structured interviews with 20 healthcare professionals in England across the referral pathway to joint replacement surgery. They were asked to talk about their experiences of referring and selecting patients with comorbidities for joint replacement surgery. The interviews were audio-recorded and transcribed verbatim. Data analysis followed a thematic analysis approach based on the principles of grounded theory.

Results

In general, the presence of comorbidities was not seen as a barrier to being referred or selected for joint replacement but was seen as a challenge to manage the patients’ journey across the referral pathway. Each professional group, concentrated on different aspects of the patients’ condition which appeared to affect how they managed patients with comorbidities. This implied there was a disagreement about roles and responsibilities in the management of patients with comorbidities. None of the professionals believed it was their responsibility to address comorbidities in preparation for surgery. This disagreement was identified as a reason why some patients seem to ‘get lost’ in the referral system when they were considered to be unprepared for surgery. Patients were then potentially left to manage their own comorbidities before being reconsidered for joint replacement.

Conclusions

At the clinician-level, comorbidities were not perceived as a barrier to accessing joint replacement surgery but at the pathway-level, it may create an implicit barrier such that patients with comorbidities may get ‘lost’ to the system. Further study is needed to explore the roles and responsibilities of professionals across the current orthopaedic referral pathway which may be less suitable for patients with comorbidities.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3565-0) contains supplementary material, which is available to authorized users.

Infection after knee replacement: a qualitative study of impact of periprosthetic knee infection

Background

Approximately 340,000 knee replacements are performed each year in the USA and UK. Around 1% of patients who have had knee replacement develop deep infection around the prosthesis: periprosthetic knee infection. Treatment often requires a combination of one or more major operations and antibiotic therapy. This study aimed to understand and characterise patients’ experiences of periprosthetic knee infection.

Methods

Qualitative semi-structured interviews were conducted with 16 patients (9 men, 7 women; 59–80 years, mean age 72) who experienced periprosthetic knee infection and subsequent revision treatment in six National Health Service orthopaedic departments. Interviews were audio-recorded, transcribed, anonymised and analysed thematically. The concept of biographical disruption was used to frame our analysis, and four transcripts double-coded for rigour. Patients were interviewed between two and 10 months after surgical revision.

Results

Participant experiences can be characterised according to three aspects of biographical disruption which we have used to frame our analysis: onset and the problem of recognition; emerging disability and the problem of uncertainty, and chronic illness and the mobilisation of resources. Participants’ experiences of infection and treatment varied, but everyone who took part reported that infection and revision treatment had devastating effects on them. Participants described use of social and healthcare support and a need for more support. Some participants thought that the symptoms that they had first presented with had not been taken seriously enough.

Conclusions

Periprosthetic knee infection and its treatment can be life-changing for patients, and there is a need for greater support throughout treatment and lengthy recovery. Future work could look at preparedness for adverse outcomes, help-seeking in impactful situations, and information for healthcare professionals about early signs and care for periprosthetic infection.

Elevation of fibrin degradation product (FDP) values prevents the negative conversion of serum CRP values after total knee arthroplasty

Background

It is essential as an orthopedic surgeon to diagnose prosthetic joint infection (PJI) at an early stage and to carry out precise treatment as well as preventing the deterioration of functional prognosis as much as possible. We suspected that PJI might have been caused because the negative conversion of creatinine reactive protein (CRP) has been prolonged after total knee arthroplasty (TKA) and patients with no serum CRP negative conversion have been treated with antibiotics to avoid the morbidity of PJI. The purpose of the present study is to investigate the factors associated with prolongation of the negative conversion of CRP, with the exclusion of PJI patients.

Methods

We performed a retrospective case control study at our institution from August 2014 to August 2016. We classified the patients into two groups based on whether it required ≥20 days (Group A, n = 23) or <20 days (Group B, n = 23) for CRP levels to normalize. Serum D-Dimer and fibrin degradation product (FDP) values were measured at 1, 2, 5, 9, 12, 16, 19, 23, 26, and 30 days after TKA. Exclusion criteria include anticoagulant oral administration cases before TKA, venous thromboembolism (VTE) by postoperative lower limb venous echocardiography before and after TKA, CRP re-elevation cases, and patients with PJI. The cutoff points for D-dimer and FDP levels for screening tests were calculated from the receiver operating characteristic (ROC) curve.

Results

The ROC analysis of D- Dimer values at 30 days after TKA yielded an AUC of 0.891 (95% confidence interval (CI) 0.858-1.000), which indicates nearly an excellent test. The cutoff point of 22.1 μg/dl for FDP value (Younden Index: 22.1 μg/dl) showed a sensitivity of 81.8% (95% CI 70.1-92.8) and a specificity of 80.0% (95% CI 67.9-89.1).

Conclusion

We revealed that CRP values of patient with an FDP level ≥22.1 μg/dl at 30 days after TKA necessarily showed negative conversion without antibiotic administration, when examining a patient with elevated serum CRP of minor criteria in the definition of PJI proposed by MSIS (other criteria do not apply).

Level of evidence

Ⅲ.

Time Trends in Characteristics of Patients Undergoing Primary Total Hip and Knee Arthroplasty in California, 2007-2010

BACKGROUND

As the number of total hip and knee arthroplasty cases increases, it is important to understand the burden of factors that impact patient outcomes of these procedures. This article examined the time trends in key demographics, clinical characteristics, comorbidity burden (Deyo-Charlson Comorbidity Index [CCI]), and presence of depression in patients undergoing primary total hip arthroplasty and total knee arthroplasty using population-based, all-payer inpatient database, California Healthcare Cost and Utilization Project, from 2007 to 2010.

METHODS

Chi-square tests and analysis of variance were used. Multivariate logistic regression analyses were also performed to compare the prevalence of depression in 2007 to later years.

RESULTS

In the primary total hip arthroplasty cohort, the prevalence of depression significantly increased by 20%, mean age decreased by 0.4 years, mean length of stay (LOS) decreased by 0.5 days, and having a CCI score of ≥3 increased by 30% (P value < .001 for all) over the study period. Similarly, in the primary total knee arthroplasty cohort, the prevalence of depression increased by 23%, the mean age decreased by 0.4 years, mean LOS decreased by 0.4 days, and the prevalence of CCI score of ≥3 increased by 35% (P value < .001 for all).

CONCLUSION

Despite the younger age of the joint arthroplasty population over time, we found increased prevalence of depression and comorbidity scores but shorter LOS. Further study is needed to determine the impact of the changing demographics of the total joint population and the best strategies to optimize their outcome with these procedures.

Effects of preoperative walking ability and patient's surgical education on quality of life and functional outcomes after total knee arthroplasty

Objective

Prospectively analyze the effect of preoperative walking status and the patient's surgical education on functional outcomes and the three dimensions of quality of life (QoL) (pain, physical function, and mental health) after elective total knee arthroplasty (TKA).

Methods

A comparative analysis on the QoL and functional outcomes in patients who underwent total knee arthroplasty between January 2014 and June 2015. To compare effects of the patient's walking status and knowledge of the surgical procedure on QoL and functional outcomes following TKA by means of SF-36 questionnaire, CES D10, VAS, KSS, KSFS, WOMAC, as well as Friedmann and Wyman scores, 10MWT, and 30-second timed chair test, assessed before the operation and one, three, and six months after the operation.

Results

There were 168 knees in 154 patients: 46.75% men and 53.24% women. 52.38% of knees had grade-III OA and 40.47% of knees had grade-IV OA. Preoperatively, SF-36 PCS was 33.2 and MCS was 35.4. Mean KSS and KSFS in females was 37.3 (16.2) and 31.5 (13.8); in males it was 49.2 (18.4) and 42.5 (15.7), respectively. Mean WOMAC scores were 64.2 in females and 56.5 in males. Mean VAS and CES D10 scores were 8.8 and 8.2 in females, and 6.9 and 6.4 in males, respectively. Post operatively at the first, third, and sixth month, significant improvements in QoL and mean SF-36, CES D10, VAS, KSS, KSFS, WOMAC, and Friedmann and Wyman scores were observed, as well as in the 10MWT and 30 s timed chair test scores. Patients with better preoperative functional activity and satisfactory understanding of TKA presented a better functional performance and achieved a good quality life (p < 0.01).

Discussion

Surgeons educate TKA candidates regarding the surgical procedure, the nature of implants, and how the procedure would affect their lifestyle and what their expectations from TKA should be. These crucial considerations should boost their confidence, enhancing their involvement and cooperation in post-surgical rehabilitation, thereby improving their QoL, functional results, and post TKA experience.

Conclusion

TKA candidates with good preoperative walking ability and understanding of knee arthroplasty have better QoL in early and late post-surgery periods. Patient's lifestyle and understanding significantly enhances the postoperative functional ability.

Severe arthritis predicts greater improvements in function following total knee arthroplasty

PURPOSE

Although excellent outcomes are routinely reported following total knee replacement, up to 20 % of patients remain dissatisfied. The aim of this study was to determine whether pre-operative radiographic classification was associated with functional outcomes following surgery.

METHODS

A retrospective review of a prospective arthroplasty database identified 256 patients that fulfilled the inclusion criteria over an 18-month period. Baseline demographic data on all patients were collected prospectively. All pre-operative radiographs were assessed using the Kellgren and Lawrence (K&L) classification system. Patients were prospectively assessed using the American Knee Society Score pre-operatively and at 1, 3 and 5 years post-surgery.

RESULTS

An association was found between the pre-operative radiographic severity of arthritis and the pre-operative American Knee Society Knee (AKSK) scores, with worsening radiographic grade corresponding to worsening AKSK scores (p = 0.020). There was an association between K&L classification and improvement in AKSK scores from pre-operative to 1 year (p = 0.003) and 3 years (p = 0.04), with K&L grades 3 and 4 demonstrating the most significant improvements. On multivariate regression analysis, K&L classification was the only significant predictor of improvement in AKSK at 1 year (p = 0.009). No correlation was found between K&L grade and the American Knee Society Functional Scores at any stage.

CONCLUSIONS

The results of this study may help to improve satisfaction rates in total knee replacement by targeting treatment. Patients can be counselled that although radiographic severity of arthritic changes can predict knee-specific functional improvement, the extent of their global functional improvement cannot.

LEVEL OF EVIDENCE

IV.

Protocol for a single-centre, parallel-arm, randomised controlled superiority trial evaluating the effects of transcatheter arterial embolisation of abnormal knee neovasculature on pain, function and quality of life in people with knee osteoarthritis

INTRODUCTION

Symptomatic knee osteoarthritis (OA) is common. Advanced knee OA is successfully treated with joint replacement surgery, but effectively managing mild to moderate knee OA can be difficult. Angiogenesis increases with OA and might contribute to pain and structural damage. Modifying angiogenesis is a potential treatment pathway for OA. The aim of the current study is to determine whether transcatheter arterial embolisation of abnormal neovasculature arising from the genicular arterial branches improves knee pain, physical function and quality of life in people with mild to moderate symptomatic knee OA.

METHODS AND ANALYSIS

The study is a single centre, parallel-arm, double-blinded (participant and assessor), randomised controlled superiority trial with 1:1 random block allocation. Eligible participants have mild to moderate symptomatic knee OA and will be randomly assigned to receive either embolisation of aberrant knee neovasculature of genicular arterial branches or a placebo intervention. Outcome measures will be collected prior to the intervention and again 1, 6 and 12 months postintervention. The primary outcome is change in knee pain between baseline and 12 month assessment as measured by the Knee Injury and Osteoarthritis Outcome Score (KOOS). Secondary outcomes include change in self-reported physical function (KOOS), self-reported quality of life (KOOS, EuroQol: EQ-5D-5L), self-reported knee joint stiffness (KOOS), self-reported global change, 6 min walk test performance, and 30 s chair-stand test performance. Intention-to-treat analysis will be performed including all participants as randomised. To detect a mean between group difference in change pain of 20% at the one year reassessment with a two-sided significance level of α=0.05 and power of 80% using a two-sample t-test, we require 29 participants per arm which allows for 20% of participants to drop out.

ETHICS AND DISSEMINATION

Barwon Health Human Research Ethics Committee, 30 May 2016, (ref:15/101). Study results will be disseminated via peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

Universal trial number U1111-1183-8503, Australian New Zealand Clinical Trials Registry, ACTRN12616001184460, approved 29 August 2016.

Differences in presentation, progression and rates of arthroplasty between hip and knee osteoarthritis: Observations from an osteoarthritis cohort study-a clear role for conservative management

Aim

To describe the natural progression and the rates of arthroplasty of a cohort of hip and knee osteoarthritis (OA) patients.

Methods

An observational study of 247 consecutive patients who attended an OA clinic between May 2008 and August 2009. Follow‐up survey was conducted from July 2014 to December 2014, with the primary end point being joint replacement surgery.

Results

One hundred and sixty‐seven patients had knee OA and 80 patients had hip OA. When adjusted for other variables (age, gender, body mass index, Kellgren‐Lawrence stage, symptom duration, presence of OA elsewhere and pain score), patients with hip OA demonstrated 86% increased hazard of surgery compared to knee OA patients (95% CI increase of 19% to 193%). At 6 years after initial consultation, 67% of patients with knee OA did not require a knee replacement surgery, while 40% (30, 51) of hip OA patients did not undergo surgery (95% CI: 59–74%). Overall at 6 years, 58% of patients (95% CI: 51–64%) did not undergo joint replacement surgery.

Conclusion

Knee and hip OA patients appear to behave differently, with hip OA patients more likely to undergo arthroplasty. There is a significant number of both hip OA and knee OA patients who did not require arthroplasty at the end of 6 years, suggesting a major role for conservative therapy.

The Effect of Geographic Units of Analysis on Measuring Geographic Variation in Medical Services Utilization

Objectives:

We aimed to evaluate the effect of geographic units of analysis on measuring geographic variation in medical services utilization. For this purpose, we compared geographic variations in the rates of eight major procedures in administrative units (districts) and new areal units organized based on the actual health care use of the population in Korea.

Methods:

To compare geographic variation in geographic units of analysis, we calculated the age–sex standardized rates of eight major procedures (coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, surgery after hip fracture, knee-replacement surgery, caesarean section, hysterectomy, computed tomography scan, and magnetic resonance imaging scan) from the National Health Insurance database in Korea for the 2013 period. Using the coefficient of variation, the extremal quotient, and the systematic component of variation, we measured geographic variation for these eight procedures in districts and new areal units.

Results:

Compared with districts, new areal units showed a reduction in geographic variation. Extremal quotients and inter-decile ratios for the eight procedures were lower in new areal units. While the coefficient of variation was lower for most procedures in new areal units, the pattern of change of the systematic component of variation between districts and new areal units differed among procedures.

Conclusions:

Geographic variation in medical service utilization could vary according to the geographic unit of analysis. To determine how geographic characteristics such as population size and number of geographic units affect geographic variation, further studies are needed.

Hip Abductor Strengthening Improves Physical Function Following Total Knee Replacement: One-Year Follow-Up of a Randomized Pilot Study

BACKGROUND

Total knee replacement (TKR) is the commonest surgical procedure for patients with severe pain and impaired physical function following end stage knee osteoarthritis. The hip abductors are well renowned in stabilization of the trunk and hip during walking, maintaining the lower limb position, and transferring the forces from the lower limbs to the pelvis.

OBJECTIVE

To assess the efficacy of hip abductor strengthening exercise on functional outcome using performance based outcome measures following total knee replacement.

METHODS

An observer blinded randomized pilot trial design was conducted at Manipal hospital, Bangalore, India. Participants designated for elective TKR were randomized to experimental group hip abductor strengthening along with standard rehabilitation (n=10) or control group standard rehabilitation alone (n=10). Participants followed for one year to assess physical function using performance based outcomes, such as timed up and go test, single leg stance test, six minute walk test, knee extensor strength and hip abductor strength.

RESULT

Eighteen participants with a mean age of 63.1 ± 5.5 years (8 Males and 10 Females) completed the study. Improvement in hip abduction strength, single leg stand test was superior in hip abductor strengthening group at 3 months and 1 year when compared to standard rehabilitation alone.

CONCLUSION

Hip abductor strengthening showed superior improvements in single leg stance test and six minute walk test. Hip abductor strengthening exercises has the potential to improve physical function following total knee replacement.

Association between Neuropathic Pain and Reported Disability after Total Knee Arthroplasty

PURPOSE

To determine whether reporting neuropathic pain (NP) at an average of 5 years after total knee arthroplasty (TKA) was related to patient age, sex, preoperative comorbidity, arthritis self-efficacy, or disability before surgery and at 1 year after surgery. The estimate of NP prevalence and cross-sectional group differences were explored at 5 years after surgery.

METHODS

A subsample of participants in a formal research study was contacted via mail approximately 5 years after undergoing surgery and were sent four questionnaires: the Western Ontario and McMaster Universities Osteoarthritis Index, the Patient Health Questionnaire, the Self-Administered Leeds Assessment of Neuropathic Signs and Symptoms (S-LANSS), and a satisfaction questionnaire. NP was defined as an S-LANSS score of 12 or more.

RESULTS

Of 89 patients who met the inclusion criteria, data for 63 (71%) patients (47 women; mean age 67 [SD 8] y) were used for analysis. Of these 63, 9 (14%) were identified as having NP. None had a report of failure of prosthesis or other surgical complications according to most recent medical records. There was no relationship between preoperative patient characteristics and development of NP. However, the NP group on average had a higher report of stiffness (p=0.020), physical dysfunction (p=0.019), and pain (p=0.050) at 1 year after surgery. Cross-sectional comparisons showed higher levels of pain (p=0.001), stiffness (p=0.008), physical dysfunction (p=0.003), and depression (p=0.005) and lower satisfaction (p=0.018) at the time of the survey than the patients without NP.

CONCLUSION

The estimated prevalence of NP was 14%. Patients with NP reported higher levels of disability as early as 1 year after surgery. They remained more disabled, with a higher level of depression and less satisfaction, at an average of 5 years after surgery.

Hyaluronic Acid Injections in Medicare Knee Osteoarthritis Patients Are Associated With Longer Time to Knee Arthroplasty

BACKGROUND

Few nonoperative treatment options for knee osteoarthritis (OA) are available, but there is ongoing debate about the effectiveness of intra-articular (IA) hyaluronic acid (HA) injections. We investigated whether the formulation of IA HA, or its combined use with IA corticosteroid (CS), may be contributing to some of the reported variation in clinical outcomes.

METHODS

The 5% Part B Medicare data (2005-2012) were used to identify knee OA patients who underwent knee arthroplasty (KA). The time from diagnosis of OA to KA was compared between patients with (HA) and without (no HA) IA HA use, using quantile regression with propensity score adjustment. These were further stratified by type of IA HA. Patient factors associated with time to KA were also assessed using Cox regression.

RESULTS

The "HA" cohort was associated with a longer time to KA of 8.7 months (95% confidence interval: 8.3-9.1 months; P < .001) compared with the "no HA" cohort, with extended time to KA in the bioengineered Euflexxa IA HA cohort. Patient factors associated with longer time to KA included women, younger patients, minority patients, patients with fewer comorbidities, and IA CS injection use. Patients with both IA HA and IA CS had an additional 6.3 months (95% confidence interval: 5.5-7.0 months; P < .001) to KA over those with only IA HA.

CONCLUSION

In a large cohort of elderly patients undergoing KA, there was a significant longer time from diagnosis of OA to KA in those receiving IA HA. It is unclear if the extended time may lead to less KA utilization.

Cognitive Citizenship: Access to Hip Surgery for People with Dementia

Dementia and chronic hip disease are both more prevalent with advancing age. Given this, the number of people with both dementia and hip disease is likely to increase in an ageing population such as the UK. This article raises questions about how people with dementia and chronic hip disease are conceptualized in the context of evidence-based medicine, and whether this conceptualization may limit unfairly their access to surgical services. The published clinical research discourse at the interface of hip disease and dementia is taken as an ‘evidence-base’, and is evaluated in terms of its suitability for informing professional decisions about viability for surgery. The analysis suggests that the outcomes criteria used to determine patient viability serve to discriminate unfairly against people with dementia. If such discrimination exists, it necessarily militates against the promotion of health-related citizenship rights of the cognitively impaired, creating an evidence-based culture that encourages a problematic model of cognitive citizenship.

The MRI-detected osteophyte score is a predictor for undergoing joint replacement in patients with end-stage knee osteoarthritis

OBJECTIVES

The aim of this prospective cohort study was to examine whether MRI-detected osteoarthritis (OA)-structural changes at baseline could predict knee OA patients who would undergo total knee arthroplasty (TKA).

METHODS

In total, 128 end-stage medial-type knee OA patients were enrolled and followed up for 6 months. MRI using the whole-organ MRI scoring (WORMS) method, radiographic findings, visual analog scale (VAS) for pain and a patient-oriented outcome measure, and the Japanese Knee Osteoarthritis Measure (JKOM) were recorded at baseline. The area under the curve (AUC) was estimated to determine the discriminative value of the prediction models.

RESULTS

While 74 patients (57.8%) did not undergo TKA, the remaining 54 patients (42.2%) underwent TKA during this period. The AUCs of the receiver operating characteristic (ROC) curve for the activities of daily living (ADL) score evaluated by the JKOM ADL score [0.70 (95% CI: 0.60-0.79)] and osteophyte score [0.72 (0.64-0.81)] were 0.70 or greater. The JKOM ADL score (17/40) and the osteophyte score (30/98) showed relative risks (RR) of 2.61 (1.32-5.15) and 3.01 (1.39-6.52) for undergoing TKA, respectively.

CONCLUSION

The osteophyte score detected by MRI, in addition to ADL score, was found to be an important factor in determining whether the patient should undergo TKA.

The relative importance of perceived doctor's attitude on the decision to consult for symptomatic osteoarthritis: a choice-based conjoint analysis study

OBJECTIVES

Some patients spend years with painful osteoarthritis without consulting for it, including times when they are experiencing persistent severe pain and disability. Beliefs about osteoarthritis and what primary care has to offer may influence the decision to consult but their relative importance has seldom been quantified. We sought to investigate the relative importance of perceived service-related and clinical need attributes in the decision to consult a primary care physician for painful osteoarthritis.

DESIGN

Partial-profile choice-based conjoint analysis study, using a self-complete questionnaire containing 10 choice tasks, each presenting two scenarios based on a combination of three out of six selected attributes.

SETTING

General population.

PARTICIPANTS

Adults aged 50 years and over with hip, knee or hand pain registered with four UK general practices.

OUTCOME MEASURES

Relative importance of pain characteristics, level of disruption to everyday life, extent of comorbidity, assessment, management, perceived general practitioner (GP) attitude.

RESULTS

863 (74%) people responded (55% female; mean age 70 years, range: 58-93). The most important determinants of the patient's decision to consult the GP for joint pain were the extent to which pain disrupted everyday life ('most' vs 'none': relative importance 31%) and perceived GP attitude ('legitimate problem, requires treatment' vs 'part of the normal ageing process that one just has to accept': 24%). Thoroughness of assessment (14%), management options offered (13%), comorbidity (13%) and pain characteristics (5%) were less strongly associated with the decision to consult.

CONCLUSIONS

Anticipating that the GP will regard joint pain as 'part of the normal ageing process that one just has to accept' is a strong disincentive to seeking help, potentially outweighing other aspects of quality of care. Alongside the recognition and management of disrupted function, an important goal of each primary care consultation for osteoarthritis should be to avoid imparting or reinforcing this perception.

The posterior condylar offset ratio and femoral anatomy in anterior versus posterior referencing total knee arthroplasty

BACKGROUND

The preservation of joint anatomy is one of the key issues in total knee arthroplasty. The effect of the prosthesis' referencing system, relative to femoral anatomy, remains unknown. It was sought to determine if femoral anatomy, following total knee arthroplasty is better maintained using either anterior referencing or posterior referencing prosthesis. The posterior condylar offset ratio (PCOR) was employed for preoperative and postoperative radiographic comparison of femoral condyles. It was hypothesized that posterior referencing prosthesis would better restore condylar morphology.

METHODS

Sixty-six patients undergoing a total knee arthroplasty with anterior referenced Zimmer(®) NexGen(®) LPS prosthesis and ninety-one with posterior referenced Tornier(®) HLS Noetos(®) were divided into two groups according to the prosthetic model used and retrospectively compared. PCOR was calculated as the quotient of the distance between the posterior condylar border and the tangent to the posterior cortex of the femoral diaphysis, and the distance between the posterior condylar border and the tangent to the anterior cortex of the femoral diaphysis. PCOR was determined preoperatively and postoperatively and compared within each group and between both groups.

RESULTS

An increase in the PCOR (P<0.0001) following surgery was observed in both anterior referencing and posterior referencing models. No difference was noted when the postoperative PCOR was compared between both groups (P=0.61).

CONCLUSION

Both anterior and posterior referencing prosthesis lead to a similar increase of the PCOR following total knee arthroplasty.

LEVEL OF EVIDENCE

Level IV.

Functional Impairment Is a Risk Factor for Knee Replacement in the Multicenter Osteoarthritis Study

BACKGROUND

Debilitating pain associated with knee osteoarthritis (OA) often leads patients to seek and complete total knee arthroplasty (TKA). To date, few studies have evaluated the relation of functional impairment to the risk of TKA, despite the fact that OA is associated with functional impairment.

QUESTIONS/PURPOSES

The purpose of our study was to (1) evaluate whether function as measured by WOMAC physical function subscale was associated with undergoing TKA; and (2) whether any such association varied by sex.

METHODS

The National Institutes of Health-funded Multicenter Osteoarthritis Study (MOST) is an observational cohort study of persons aged 50 to 79 years with or at high risk of symptomatic knee OA who were recruited from the community. All eligible subjects with complete data were included in this analysis. Our study population sample consisted of 2946 patients with 5796 knees; 1776 (60%) of patients were women. We performed a repeated-measures analysis using baseline WOMAC physical function score to predict the risk of TKA from baseline to 30 months and WOMAC score at 30 months to predict risk of incident TKA from 30 months to 60 months. We used generalized estimating equations to account for the correlation between two knees within an individual and across the two periods. We calculated relative risk (RR) of TKA over 30 months by WOMAC function using a score of 0 to 5 as the referent in multiple binomial regressions with log link.

RESULTS

Those with the greatest functional impairment (WOMAC scores 40-68; 62 TKAs in 462 knee periods) had 15.5 times (95% confidence interval [CI], 7.6-31.8; p<0.001) the risk of undergoing TKA over 30 months compared with the referent group (12 TKAs in 3604 knee periods), adjusting for basic covariates, and 5.9 times (95% CI, 2.8-12.5; p<0.001) the risk after further adjusting for knee pain severity. At every level of functional limitation, the RR for TKA for women was higher than for men, but interaction with sex did not reach significance after adjustment for covariates including ipsilateral pain (p=0.138).

CONCLUSIONS

Baseline physical function appears to be an important element in patients considering TKA. Future studies should examine whether interventions to improve function can reduce the need for TKA.

LEVEL OF EVIDENCE

Level III, observational cohort study.

Preoperative predictors of postoperative opioid usage, pain scores, and referral to a pain management service in total knee arthroplasty

BACKGROUND

Little is known about preoperative predictors of postoperative pain and referral to a recuperative pain management service after total knee arthroplasty (TKA).

QUESTIONS/PURPOSES

We sought to identify the preoperative predictors of postoperative pain scores, referral to a pain management service, and narcotic usage in patients undergoing primary total knee arthroplasty.

METHODS

We performed a prospective cohort study of 97 TKAs from a single surgeon. Pre and 6-week postoperative WOMAC, visual analog pain scale (VAS) scores, narcotic usage, and catastrophizing pain scores were collected.

RESULTS

After adjusting for all other variables, higher age and catastrophizing pain scores were associated with lower odds of postoperative opioid usage. Increasing age and BMI were associated with lower odds of being referred to pain management. There was no relationship between self-reported preoperative pain tolerance and postoperative change in WOMAC or VAS pain scores.

CONCLUSIONS

This information may help surgeons advise their patients preoperatively and set expectations during the recovery period.

Osteoarthritis: Patient Expectations about Future Pain, Stiffness and Function

OBJECTIVES

The aim of the present study was to examine the difference between osteoarthritis patients' self-reported assessments of current pain, stiffness and physical function and their expectations of these symptoms in one and five years' time, and to determine the significant predictors of positive expectations.

METHODS

Eighty patients completed ratings of baseline assessments and one- and five-year expectations of pain, stiffness and physical function using the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Measures of illness perceptions, coping styles, health values, satisfaction, quality of life, optimism, self-esteem and moods were also collected at baseline. Agreement between patients' current assessment and expectations were calculated using intra-class correlations (ICCs). Paired-sample t-tests were conducted to look at differences between assessments. Univariate logistic regressions were then performed to identify the variables significantly associated with positive expectations of pain, stiffness and function. Significant variables (p < 0.05) were entered into a forward stepwise multivariate logistic regression to identify unique independent predictors of positive expectations for each of the WOMAC subscales.

RESULTS

Differences were found between current assessments and expectations, with the majority of patients being positive about future symptoms. There were some differences between the predictors for one- and five-year expectations, with current assessments of health status only affecting five-year expectations.

CONCLUSIONS

It is necessary to investigate further the variables that may contribute to positive expectations in osteoarthritis patients in order to manage the condition more effectively.

The effect of osteoarthritis on 1-year risk of ischemic heart disease following total knee arthroplasty

To evaluate the long-term risk of ischemic heart disease (IHD) following total knee arthroplasty (TKA), we conducted a retrospective cohort study using data from the National Health Insurance Research Database of Taiwan. We evaluated 3599 primary TKA patients and 14,396 matched control patients. We further classified all patients into those with and without osteoarthritis (OA). The incidence rate of IHD was significantly higher among the TKA patients than among the matched control patients (1.13 vs 0.69 per 1000 person-months, P<.05). However, after controlling for OA, this difference was non-significant (HR=1.18, 95% confidence interval (CI): 0.63-2.20, P>.05). Our study results indicate that underlying OA conditions are predominantly responsible for increased long-term risk of IHD in TKA patients.

Prevalence of knee pain and knee OA in southern Sweden and the proportion that seeks medical care

OBJECTIVE

The aim of this study was to estimate the prevalence of frequent knee pain in radiographic, symptomatic and clinically defined knee OA in middle-aged and elderly patients and the proportion that seeks medical care.

METHODS

In 2007 a random sample of 10 000 56- to 84-year-old residents of Malmö, Sweden, were questioned about knee pain. We classified subjects reporting knee pain with a duration of at least 4 weeks as having frequent knee pain. A random sample of 1300 individuals with frequent knee pain and 650 without were invited for assessment by the ACR clinical knee OA criteria and for bilateral weight-bearing knee radiography. We considered a Kellgren-Lawrence grade ≥2 as radiographic knee OA and that in combination with frequent knee pain as symptomatic knee OA. By linkage with the Skåne Healthcare Register, we determined the proportion of subjects that had consulted for knee OA or pain.

RESULTS

The 10 000 subjects had a mean age of 70 years (s.d. 7.6), a mean BMI of 27.1 kg/m(2) and 62% were women. The prevalence of frequent knee pain was 25.1% (95% CI 24.1, 26.1), higher in women and similar across age groups. The prevalence of radiographic knee OA was 25.4% while 15.4% had either symptomatic or clinically defined knee OA. Of these, 68.9% consulted a physician for knee OA or pain during 2004-11.

CONCLUSION

Fifteen per cent of middle-aged or elderly individuals have knee OA and symptoms. About one in three of those do not consult a physician. Inefficient care of OA and self-coping may be an explanation.

Electronic health databases for epidemiological research on joint replacements: considerations when making cross-national comparisons

PURPOSE

The purpose of this study was to examine the rate of primary knee, hip, or shoulder replacement among persons with osteoarthritis (OA) of the knee by gender and age comparing two nations in similar periods using electronic health records, but with different health-care systems.

METHODS

Two electronic health care databases of anonymized information were used to construct cohorts of adults with OA of the knee from the United Kingdom (UK) and the United States. Patients were required to have activity in the database at least 6 months before the first diagnosis of knee OA ("index diagnosis") in the study period to ensure that the patient samples were eligible for medical evaluation. The outcomes (numerator) measured were primary knee, hip, or shoulder replacement or the composite of primary knee, hip, or shoulder replacement. The denominator was the person-time at risk computed from time from the date of the index diagnosis to the date of each outcome separately or to the end of the database period if no outcome was documented.

RESULTS

There were 93,146 subjects in the UK and 1,468,217 in the United States who were aged 18+ years and met the study eligibility criteria. The composite joint replacement rate (hip, knee, or shoulder) ranged from 11.89 per 100 person-years (PY) in the Unites States to 4.13 per 100 PY in the UK Primary knee replacements rates ranged from 10.38 per 100 PY in the Unites States to 3.40 per 100 PY in the UK and occurred at a somewhat higher rate in males than females in both countries. Both primary hip and shoulder replacement rates were higher in the Unites States than in the UK (hip: 1.19 per 100 PY and 0.76 per 100 PY; shoulder: 0.19 per 100 PY and 0.03 per 100 PY, respectively). The median time to a primary hip or knee replacement in the UK was approximately twice as long as in the Unites States.

CONCLUSIONS

Knee replacements are not an uncommon event in persons with knee OA occurring throughout the adult life span, with the rate steeply rising in both sexes until aged 75 years. Although the pattern of the age-specific joint replacement rates was similar between sexes, the magnitude of the rates was markedly lower in the UK.

Living with osteoarthritis: a systematic review and meta-ethnography

OBJECTIVES

To review and synthesize the existing literature on the experience of living with a diagnosis of hip and/or knee osteoarthritis (OA).

METHOD

A systematic review was undertaken using meta-ethnography. A search of both published (AMED, CINAHL, EMBASE, PsychINFO, SportsDisc, MEDLINE, Cochrane Clinical Trials Registry, PubMed) and unpublished/trial registry databases [World Health Organization (WHO) International Clinical Trials Registry Platform, Current Controlled Trials, the United States National Institute of Health Trials Registry, National Institute for Health Research (NIHR) Clinical Research Portfolio Database] was undertaken from their inception to 5 June 2013.

RESULTS

Thirty-two studies formed the meta-ethnography of the lived experiences of people with OA. In total, 1643 people with OA were sampled, the majority diagnosed with knee OA. The evidence base was weak to moderate in quality. The majority of studies indicated that people viewed living with OA negatively. Four key factors influenced their attitudes to the condition: the severity of their symptoms; the impact of these symptoms on their functional capability; their attitude towards understanding their disease; and their perceptions of other people's beliefs towards their disease.

CONCLUSIONS

The current literature suggests that greater knowledge of the pathology of OA, management of symptoms, promotion of functional activity for patients and their family/friends networks, and understanding to better inform OA patient's role in society are all important elements that affect a person's attitude to OA. By better understanding these factors during future consultations, clinicians may forge stronger relationships with their patients to more effectively manage this long-term disabling condition.

Disability for daily living is a predictor for joint replacement in patients with end-stage knee osteoarthritis

The objective indicators which reflect the past results of end-stage knee osteoarthritis (OA) patients who have already received total knee arthroplasty (TKA) could be helpful for physicians to discuss with patients who are considering TKA. The aim of this prospective cohort study was to examine whether we could predict the knee OA patients who would receive TKA in advance based on baseline data, and to set cut-off points for receiving TKA. The two-hundred and forty end-stage medial-type knee OA patients were enrolled and followed up for 6 months while performing therapeutic exercises. Radiographic findings, visual analog scale for pain and a patient-oriented outcome measure, the Japanese Knee Osteoarthritis Measure (JKOM), were recorded at baseline. Relative risks (RRs) using the area under the curve (AUC) for a receiver operating characteristic (ROC) curve were calculated to evaluate several scores for receiving TKA. While 119 patients (55.3 %) did not undergo TKA, the remaining 96 patients (44.7 %) underwent TKA during this period. The AUCs of the ROC curve for the JKOM total score [0.71 (95 % CI 0.64-0.79)] were higher than those for radiographic parameters. Among the JKOM subcategories, JKOM category III, which indicates the condition in daily life, showed the highest AUC of 0.72 (0.65-0.80). The JKOM total score (65/100) and JKOM category III score (17/40) showed RRs of 2.20 (1.33-3.63) and 1.95 (1.18-3.22) for receiving TKA, respectively. The presence of disability in daily living was found to be an important factor determining whether the patient should undergo TKA.

What influences patients with osteoarthritis to consult their GP about their symptoms? A narrative review

BACKGROUND

Osteoarthritis (OA) is a common cause of disability and consultation with a GP. However research suggests the majority of sufferers choose not to consult their GP regarding their symptoms. Understanding the reasons for consulting is central to optimising patient outcomes. This review aims to summarise existing literature to identify what influences patients with OA to consult their GP.

METHODS

Due to the diversity of both qualitative and quantitative research that has addressed this research question a narrative review of literature has been conducted, backed up by a systematic literature search.

RESULTS

Nineteen papers were identified describing influences on consulting behaviour in patients with likely OA. Health beliefs, such as perceiving OA as an inevitable part of older age about which nothing can be done, in addition to perceiving a negative attitude of the GP, are disincentives to consulting. Severity of pain and disruption of daily activities are important influences towards consultation. Social issues such as the availability of support networks are also likely to be influential. Evidence is lacking about the impact of multi-morbidity on consulting behaviour.

CONCLUSIONS

Pain and disruption of activities appear to push towards consulting and negative attitudes regarding OA (from either the patient or GP) appear to be disincentives to consulting. Findings are limited by estimates of consultation frequency and research involving observation of consultations may improve understanding of these issues. Specifically, further research may address how pain and disrupted function are addressed and if negative attitudes are evident in the consultation.

Patellar tilt and thickness do not influence postoperative flexion in a high-flex design total knee arthroplasty

PURPOSE

The purpose of this short-term study was to determine whether patellar thickness and tilt influence the postoperative flexion in a high-flex design total knee arthroplasty (TKA).

METHODS

Between 2007 and 2009, 106 patients underwent surgery for TKA using rotating platform flex prosthesis (DePuy, Warsaw, Ind). All of them were suffering from end-stage osteoarthritis. All patients were evaluated preoperatively and at 12 months of follow-up. Maximum active, non-weight-bearing flexion was the primary outcome parameter. Standard standing antero-posterior and lateral weight-bearing radiographs were made. The patellofemoral joints were evaluated in skyline views taken with the knees at approximately 60° of flexion. Patellar thickness, patellar tilt, Caton-Deschamps indices and lower limb alignment were measured.

RESULTS

The mean flexion observed before surgery was 125° ± 15° and after 1 year was 128° ± 13°. The mean patellar thickness preoperatively was 24.5 ± 2.9 and 25.8 ± 3.2 mm at 12 months after surgery. The mean patellar tilt before the procedure was 2.9° ± 4.1° and after 12 months of follow-up was -0.8° ± 5.0°. The mean preoperative hip-knee-ankle was 2.6° ± 6.2°. No significant correlation was found between postoperative patellar tilt and thickness and postoperative flexion (n.s.).

CONCLUSIONS

Patellar tilt and thickness after TKA are factors that depend on the surgery. The resection of the patella can influence both patellar thickness and patellar tilt. By developing adequate surgical instruments, it would be possible to avoid the occurrence of an exaggerated patellar tilt or a major difference in patellar thickness. However, these two factors did not seem to influence the postoperative flexion in a high-flex design TKA, which can be seen as one of the most important outcome factors after TKA.

Variability in recommendations for total knee arthroplasty among rheumatologists and orthopedic surgeons

OBJECTIVE

The most rapidly growing population of patients undergoing total knee arthroplasty (TKA) is under the age of 65. The objective of our study was to gain insight into the factors influencing physicians' recommendations for persons in this age group with moderate osteoarthritis (OA).

METHODS

Rheumatologists and orthopedic surgeons attending national meetings were asked to complete a survey including a standardized scenario of a 62-year-old person with knee OA who has moderate knee pain limiting strenuous activity despite medical management. We used an experimental 2 × 2 × 2 design to examine the effects of sex, employment status, and severity of radiographic OA on physicians' recommendations. Each physician was asked to rate a single scenario.

RESULTS

The percentage of physicians recommending TKA varied from 30% to 55% for scenarios describing a patient with mild radiographic OA, and from 39% to 71% for scenarios describing a patient with moderate radiographic OA. Surgeons were less likely to recommend TKA for women compared to men of the same age, employment status, symptom severity, and functional status, and radiographs. Rheumatologists practicing in academic settings were more likely to recommend TKA compared to those practicing in nonacademic settings, and American surgeons were more likely to recommend TKA compared to their European counterparts.

CONCLUSION

Orthopedic surgeons and rheumatologists vary significantly in their recommendations for patients with moderate knee pain and functional limitations. Both patient and physician characteristics influence physicians' recommendations, and rheumatologists and orthopedic surgeons display different patterns of decision making.

Comparison of HRQL between unicompartmental knee arthroplasty and total knee arthroplasty for the treatment of osteoarthritis

This retrospective study evaluates the health related quality of life (HRQL) of patients following unicompartmental knee arthroplasty (UKA) compared to total knee arthroplasty (TKA) for osteoarthritis treatment. The Western Ontario and McMaster Osteoarthritis index (WOMAC) and the Oxford Knee score (OKS) were recorded at baseline, 3 and 6 months. Analysis of 317 UKAs and 425 TKAs showed no significant differences in HRQL between the two groups at baseline, but the TKA group was significantly older and more likely to be male. Both groups showed an overall improvement in the total WOMAC and OKS over time, with males showing significant improvement over females. Adjusting for age and gender, there was no significant difference between UKA and TKA in HRQL over the first 6 months following surgery.

Inflammatory predictors of ongoing pain 2 years following knee replacement surgery

INTRODUCTION

The prevalence of unrelieved pain following total knee arthroplasty (TKA) is substantial.

OBJECTIVE

We asked if cytokine markers of inflammation in preoperative serum or knee synovial fluid (SF) would predict pain 2 years following TKA.

METHODS

Demographic data and functional outcomes were recorded at baseline and 2 years with the WOMAC index. Serum and SF tissue samples were collected at the time of surgery. Linear regression modeling was used to determine the relationship between SF/serum inflammatory markers and a lesser improvement in self reported pain at two years follow-up.

RESULTS

Of our 28 patient cohort, significant correlations between serum and SF levels were found for IL-1β (p<0.002), MIP-1β (p<0.001), adiponectin (p<0.001) and leptin (p<0.001). Adjusted analysis showed that greater SF concentrations of TNF-α, MMP-13 and IL-6 were independent predictors of less pain improvement at two years follow-up (p<0.05).

CONCLUSIONS

Those patients, having ongoing pain despite no clinical or radiological cause, may have an inflammatory profile characterizing a predisposition to ongoing pain after TKA.

LEVEL OF EVIDENCE

Prognosis study, Level 2.

Defining the content of an opportunistic osteoarthritis consultation with primary health care professionals: a Delphi consensus study

OBJECTIVE

To define the core content for an opportunistic consultation between a health care professional (HCP) and a patient with osteoarthritis (OA) in primary care.

METHODS

An ideas generation round and a 2-round Delphi postal consensus study allowed participants to rank the importance of tasks for an opportunistic consultation. The study was conducted with a lay group (n = 18) and 3 groups of HCPs (n = 30 for general practitioners, n = 19 for practice nurses, and n = 37 for allied health professionals).

RESULTS

The ideas generation round formulated 35 consultation tasks. There was a 50% response rate to the 2-round postal exercise (n = 52). Consensus was reached on 12 tasks for an opportunistic OA consultation using a >80% level of agreement across all groups. Three of these consultation tasks were defined at 100%. The 3 tasks were questions asked by the HCP about how things are going with the condition, the type and amount of pain the patient has, and whether the patient is taking regular analgesia.

CONCLUSION

In a Delphi study to define the content of an opportunistic primary care OA consultation, 12 consultation tasks provided the content of a comprehensive consultation. Three of these tasks with 100% agreement could be adopted in any multidisciplinary consultation for OA in primary care. Inquiring about the condition, the type and amount of pain the patient has, and whether analgesia is being taken forms a core set of questions that are considered important by both lay and health professional groups in an opportunistic consultation.