Patient-reported Outcome Measures of Revision Total Hip Arthroplasty for Prosthetic Joint Infection is not Inferior to Aseptic Revision Total Hip Arthroplasty

@#Introduction: This study aims to investigate whether patients undergoing two-stage revision total hip arthroplasty (THA) for prosthetic joint infection (PJI) and one-stage revision THA for aseptic reasons have similar clinical outcomes and patient satisfaction during their post-operative follow-up. We hypothesise that the two-stage revision THA for PJI is associated with poorer outcomes as compared to aseptic revision THA. Materials and Methods: We reviewed prospectively collected data in our tertiary hospital arthroplasty registry and identified patients who underwent revision THA between 2001 and 2014, with a minimum of two years follow-up. The study group (two-stage revision THA for PJI) consists of 23 patients and the control group (one-stage revision THA for aseptic reasons) consists of 231 patients. Patient demographics, Western Ontario and McMaster Universities Arthritis Index (WOMAC), Oxford Hip Score (OHS), Short Form-36 (SF-36) scores and patient reported satisfaction were evaluated. Student’s t-test was used to compare continuous variables between the two groups. Statistical significance was defined as p <0.05. Results: The pre-operative demographics and clinical scores were relatively similar between the two groups of patients. At two years, patients who underwent revision THA for PJI reported a better WOMAC Pain Score and OHS as compared to aseptic revision THA. A similar proportion of patients were satisfied with their results of surgery in both groups (p=0.093). Conclusions: Although patients who underwent revision THA for PJI had poorer pre-operative functional scores (WOMAC function and SF-36 PF), at two years follow-up, these two groups of patients have comparable post-operative outcomes. Interestingly, patients who had revision THA for PJI reported a better clinical outcome in terms of OHS and WOMAC Pain score as compared to the aseptic group. We conclude that the revision THA for PJI is not inferior to aseptic revision THA in terms of patient satisfaction and clinical outcomes.

Duloxetine reduces morphine requirements after knee replacement surgery.

BACKGROUND: Multimodal analgesia is advocated for perioperative pain management to reduce opioid use and its associated adverse effects. Serotonin and norepinephrine are involved in the modulation of endogenous analgesic mechanisms via descending inhibitory pain pathways in the brain and spinal cord. An increase in serotonin and norepinephrine may increase inhibition of nociceptive input and improve pain relief. Duloxetine, a selective serotonin and norepinephrine reuptake inhibitor, has demonstrated efficacy in chronic pain conditions such as painful diabetic neuropathy and post-herpetic neuralgia. The objective of the study was to evaluate the efficacy of duloxetine in reducing morphine requirements in patients after knee replacement surgery. METHODS: Fifty patients received either two doses of oral duloxetine 60 mg (2 h before surgery and on first postoperative day) or placebo. All patients received patient-controlled analgesia with morphine for 48 h after operation. Pain and adverse effects were assessed at 0.5, 1, 2, 6, 12, 24, and 48 h after surgery on an 11-point numeric rating scale. RESULTS: Twenty-three patients in the duloxetine group and 24 patients in the placebo group completed the study. Morphine requirements during the 48 h after surgery were significantly lower in the duloxetine group [19.5 mg, standard deviation (sd) 14.5 mg] compared with the placebo group (30.3 mg, sd 18.1 mg) (P=0.017). There were no statistically significant differences between the groups in pain scores (at rest and on movement) or in adverse effects. CONCLUSIONS: Perioperative administration of duloxetine reduced postoperative morphine requirements during the first 48 h after knee replacement surgery, without significant adverse effects.

Rasch analysis of the Oxford Knee Score.

OBJECTIVES: Use Rasch analysis to examine the psychometric properties of the Oxford Knee Score (OKS), particularly in respect to unidimensionality, and consistency of item functioning before and after total knee replacement and across age and gender groups. METHODS: The 12-item OKS was administered to 1,712 patients before the surgery, and 1,322 and 855 patients were administered the instrument repeatedly at the 6-month and 2-year postoperative assessments, respectively. Data were fitted to the Rasch partial credit model with the Winsteps program. Differential item functioning (DIF) analysis was performed, and fit statistics in combination with principal components analysis of the residuals were used to test the unidimensionality assumption. The fit criteria were set at 1.5 and 2.0 for infit mean-square (MNSQ) and outfit MNSQ, respectively. RESULTS: At baseline, item difficulty ranged from -1.86 to 1.78 logits, and person measures had a mean+/-SD of -0.01+/-0.89. Misfit items were "limping" and "night pain" in preoperative data and "limping" and "kneeling" in postoperative data. After removing items limping and kneeling and recoding item night pain, none of the items misfit at each of the time points and there was stability of item difficulty ordering across time. In the modified OKS set, five items displayed DIF by age and three by gender. CONCLUSION: The original OKS had adequate targeting and good coverage of knee severity levels in preoperative patients. The modified 10-item OKS data fit the Rasch model and had stable item difficulty ordering over time.

Validation of the International Classification of Functioning, Disability, and Health (ICF) Brief Core Set for osteoarthritis.

OBJECTIVE: To validate the International Classification of Functioning, Disability, and Health (ICF) Brief Core Set for osteoarthritis (OA) by comparing the preliminary Brief Core Set to a selection of categories from the Comprehensive Core Set that explain most of the variance of functioning and health. METHODS: Patients with knee OA were asked to complete the Case Report Form for Patients, which includes the 36-item Short Form Health Survey (SF-36) and the Self-administered Comorbidity Questionnaire (SCQ). For each patient, the research staff was asked to complete the Case Report Form for Health Professionals, which includes the ICF Comprehensive Core Set for OA. Two individual questions regarding patients' general health and functioning were completed by both the patients and the research staff. The ICF categories to be entered into an initial regression model were selected following systematic steps in accordance with the ICF structure. Based on the initial models, additional models were generated by systematically substituting the ICF categories included in the initial models with other highly intercorrelated categories. RESULTS: A consecutive sample of 122 patients completed this study. Sixteen candidate ICF categories were identified by 15 linear regression models, which accounted for 5.5-57.7% of the total variance. Besides the two categories, b710 and b730, that are already included in the preliminary Brief Core Set, 14 additional categories were identified to be potential candidates for the Core Set. CONCLUSIONS: This study complemented the development of the Brief Core Set, which should be further refined by incorporating the opinions of patients, clinicians, and statisticians.

Peri-articular steroid injection improves the outcome after unicondylar knee replacement: a prospective, randomised controlled trial with a two-year follow-up.

We have performed a prospective double-blind, randomised controlled trial over two years to evaluate the efficacy and safety of an intra-operative peri-articular injection of triamcinolone acetonide in patients undergoing medial unicondylar knee replacement. We randomised 90 patients into two equal groups. The study group received an injection of triamcinolone acetonide, bupivacaine, and epinephrine into the peri-articular tissues at the end of the operation. The control group received the same injection mixture but without the addition of triamcinolone. The peri-operative analgesic regimen was standardised. The study group reported a significant reduction in pain (p = 0.014 at 12 hours, p = 0.031 at 18 hours and p = 0.031 at 24 hours) and had a better range of movement (p = 0.023 at three months). There was no significant difference in the rate of infection and no incidence of tendon rupture in either group. The addition of corticosteroid to the peri-articular injection after unicondylar knee replacement had both immediate and short-term benefits in terms of relief from pain, and rehabilitation with no increased risk of infection.

Cross-cultural adaptation and validation of Singapore English and Chinese Versions of the Oxford Knee Score (OKS) in knee osteoarthritis patients undergoing total knee replacement.

OBJECTIVE: To cross-culturally adapt and validate Singapore English and Chinese versions of the Oxford Knee Score (OKS) in patients with knee osteoarthritis (OA) undergoing total knee replacement (TKR) surgery. METHODS: Singapore English and Chinese OKS versions were cross-culturally adapted from the source English version following standard guidelines (including cognitive debriefing), and validated by interviewing patients in English or Chinese using an identical, pretested questionnaire containing the OKS, Short Form 36, and EQ-5D. Reliability was assessed using Cronbach's alpha, dimensionality using principal component factor analysis and item-total correlations, convergent and divergent construct validity by assessing six and three a priori hypotheses, respectively. RESULTS: The Singapore English and Chinese OKS were well accepted by patients in pilot testing. When administered to a consecutive sample of 127 English and 131 Chinese-speaking Singaporeans with knee OA (mean age 66 years, 83% female, mean duration of OA 6 years, Chinese:Malay:Indian:Others=78:7.9:11:3.1% for English version), Cronbach's alpha exceeded 0.8 and factor analysis yielded three factors for both versions. Hypothesized item-total correlations (Spearman's rho > or = 0.4) were observed for all items except limping, kneeling, and night knee pain in both versions. Convergent construct validity was supported by the presence of hypothesized moderate/strong correlations (rho=0.37-0.73) for six and five a priori hypotheses in English and Chinese versions, respectively. Divergent construct validity was supported by the presence of weak correlations (rho=0.09-0.30) for all three a priori hypotheses in both versions. CONCLUSION: Singapore English and Chinese OKS demonstrated good patient acceptability and psychometric properties (including construct validity) among multiethnic Asian patients with knee OA undergoing TKR.

Cross-cultural adaptation and validation of Singapore English and Chinese versions of the Lequesne Algofunctional Index of knee in Asians with knee osteoarthritis in Singapore.

OBJECTIVE: To cross-culturally adapt and validate Singapore English and Chinese versions of the Lequesne Algofunctional Index of knee in patients with knee osteoarthritis (OA) in Singapore. METHODS: Singapore English and Chinese versions were cross-culturally adapted from the source English version following standard guideline (including cognitive debriefing). Patients were asked to complete an identical, pretested questionnaire containing the Lequesne index, Short Form 36 Health Survey (SF-36), and EQ-5D twice within 6 days. Reliability was assessed using Cronbach's alpha and intraclass correlation coefficients (ICC). Dimensionality was assessed by principal component factor analysis. Construct validity was tested by item-to-scale correlations and 12 and six a priori hypotheses for convergent and divergent construct validities, respectively. RESULTS: Singapore English and Chinese Lequesne indices were well accepted by patients in pilot testing and were therefore administered to a consecutive sample of 127 English- and 131 Chinese-speaking Singaporeans with knee OA. Acceptable internal consistency was observed for activities of daily living and the global index (alpha=0.72-0.82), and the good test-retest reliability for all scales in both versions (ICC=0.66-0.94). Expected item-to-scale correlations were presented only in activities of daily living in both versions. Factor analysis yielded two factors for both versions. Convergent and divergent construct validities were supported by the presence of hypothesized correlations between the Lequesne index and SF-36 and EQ-5D scales. CONCLUSION: Both versions of the Lequesne index demonstrated acceptable reliability and validity among multiethnic Asian patients with knee OA, which suggests that it could be used as a global index in the health-related quality of life (HRQoL) measurements in Singapore and possibly other Asian countries.

Cross-cultural adaptation and validation of Singapore English and Chinese versions of the Knee injury and Osteoarthritis Outcome Score (KOOS) in Asians with knee osteoarthritis in Singapore.

OBJECTIVE: To cross-culturally adapt and validate Singapore English and Chinese versions of the Knee injury and Osteoarthritis Outcome Score (KOOS) in patients with knee osteoarthritis (OA) in Singapore. METHODS: Singapore English and Chinese versions were cross-culturally adapted from the source English KOOS following standard guidelines (including cognitive debriefing). Patients were asked to complete identical questionnaires containing the KOOS, Short Form 36 Health Survey, and EQ-5D twice within 6 days. Reliability was assessed using Cronbach's alpha and intraclass correlation coefficients (ICC), dimensionality using item-to-domain correlations and convergent and divergent construct validity using 14 and 13 a priori hypotheses, respectively. RESULTS: Singapore English and Chinese KOOS versions were well accepted by patients in pilot testing and were therefore administered to a consecutive sample of 127 English and 131 Chinese-speaking Singaporeans with knee OA. Cronbach's alpha exceeded 0.7 for all domains except for Chinese pain and symptoms domains. ICC exceeded 0.7 for all domains except for English sport and recreation and Chinese knee-related QoL domains. Hypothesized item-to-domain correlations (Spearman's rho>or=0.4) were observed for 38 items in English and 29 in Chinese versions. Convergent construct validity was supported by the presence of hypothesized moderate/strong correlations (rho=0.37-0.65) for 13 and 11 a priori hypotheses in the English and Chinese KOOS, respectively. Divergent construct validity was supported by the presence of weak correlations (rho=0.02-0.34) for 12 and 11 a priori hypotheses in the English and Chinese KOOS, respectively. CONCLUSION: The Singapore English and Chinese KOOS were well accepted and demonstrated acceptable reliability and validity in Asian patients with knee OA in Singapore.

Are they relevant? A critical evaluation of the international classification of functioning, disability, and health core sets for osteoarthritis from the perspective of patients with knee osteoarthritis in Singapore.

OBJECTIVES: To determine the extent to which health items identified from the perspective of patients with knee osteoarthritis can be linked with the International Classification of Functioning, Disability and Health (ICF); and to evaluate critically the content validity of ICF comprehensive and brief core sets for osteoarthritis. METHODS: Items identified from a focus group study were linked independently by two researchers based on the 10 a priori linking rules. Both percentage agreement and kappa statistics were calculated to measure interobserver agreement. Any disagreements were resolved by reaching a consensus among the researchers. The categories linked with all items were compared with the comprehensive core set, while the categories linked with those items reported as important by over 30% of subjects within each of three local ethnic groups (Chinese, Malay, and Indian) were compared with the brief core set. Both comparisons were made only at the second level of the ICF. RESULTS: In all, 74 items were linked with 44 different ICF categories through 105 linkages with generally good interobserver agreement. The 69 items were linked with the ICF at the third or fourth levels. Both commonalities and disparities were found through comparison between the categories linked with these items and both core sets. CONCLUSIONS: All items could be successfully linked with the ICF. The comprehensive core set showed good content validity, while the brief core set needs to be supported by more empirical evidence in various sociocultural contexts. This study specifically complemented the development and refinement of both core sets from the perspective of patients with knee osteoarthritis.

What health domains and items are important to patients with knee osteoarthritis? A focus group study in a multiethnic urban Asian population.

OBJECTIVES: To determine important health-related quality of life (HRQoL) domains and items within each domain affected by knee osteoarthritis (OA), identify ethnic variations in the importance of these domains and items among three ethnic groups, and determine how identified domains and items mapped onto selected OA-specific HRQoL instruments. METHODS: Focus groups were conducted among subjects with knee OA stratified by gender, ethnicity, and language spoken. All focus groups were audio-taped and transcribed verbatim, with subsequent translation into English for groups conducted in other languages. Data analysis was performed by combining the key elements of grounded theory and content analysis with the assistance of the qualitative software ATLAS/ti 5.0. RESULTS: Five domains (pain, physical disability, other symptoms of OA, mental health, and social health) were identified from the 74 items reported as important by at least one subject. These domains were important for subjects from all ethnic groups with the exception of social health, which was more often important for Malay subjects. Items more commonly reported as important in the pain, physical disability, and other symptoms of OA domains were generally similar across ethnic groups. In contrast, important items in the mental and social health domains differed among ethnic groups. CONCLUSIONS: The impact of knee OA on HRQoL is broadly similar in both Asian and Western socio-cultural contexts. Both similarities and differences in important domains and items were identified among subjects with knee OA from three major Asian ethnic groups.

Isolated metal- backed patellar component revision following total knee arthroplasty / 中华骨科杂志

Objective To analyse the reasons of failure of metal- backed patellar component and observe the clinical outcome of the revision procedure. Methods Thirty isolated patellar revision for failed metal- backed patellar components following total knee arthroplasty in 22 patients were reviewed. All had similar total condylar knee prosthesis inserted with retention of the posterior cruciate ligament and resurfacing of the patella. There were 4 males and 18 females. Knee Society Score rating system was used for the final evaluation. Results In average the failure occurred in 62.3 months (ranged from 26 to 96 months). The majority of patients presented with metallic crepitus(80％ ) and pain of the knee(70％ ). At surgery, full thickness polyethylene wear exposing the metal- backing was present in 76.7％ with surface damage of the femoral components in 36.7％ . There was tilting of patella in 9 knees and dislocation of patella in 2 knees. All 30 knees underwent successful isolated patellar component revision with cemented polyethylene patellar buttons. Final follow- up averaged 42.5 months, all manifestations were reported significant improvement in 22 patients. The average knee score improved from 73 points(ranged from 27 to 88) pre- revision to 87 points(ranged from 60 to 100) at the final follow- up. Conclusion Resurfacing of the patella in total knee arthroplasty with metal- backed patellar components carries a significant risk of early failure. Malalignment and maltracking of patella may be a predisposing factor to early failure in metal- backed patellar components.