Ethnic differences in preoperative function of patients undergoing total knee arthroplasty

The Shoulder Function “Tipping-Point” for Elective Rotator Cuff Repair: Demographic and Longitudinal Trends

Background

A patient's decision to undergo an elective orthopedic procedure is largely based on their symptoms and functional limitations. This point where patients choose to undergo surgery is known as the “tipping point.” The primary aim of this study is to determine the relationship between demographic parameters and the tipping point for elective rotator cuff repair. The secondary aim is to investigate if the tipping point is associated with mental health. The tertiary aim is to determine if the tipping point changes over time.

Methods

Retrospective chart review was used to identify all patients who underwent primary arthroscopic rotator cuff repair between January 1, 2015, to January 1, 2020, with 1 of 3 board-certified orthopedic surgeons. Exclusion criteria included age <18 years, revision surgery, or incomplete datasets (American Shoulder and Elbow Surgeons [ASES], 12-item short form, demographic information, and surgical history). Preoperative ASES score was designated as the tipping point for an individual patient, with a lower score representing worse shoulder function and therefore a higher tipping point and vice versa. Demographic parameters (age, sex, body mass index [BMI], race, and insurance), hand dominance, and surgical history extracted from chart review were analyzed to determine associations with tipping point.

Results

A total of 2153 patients were identified from chart review, with 1731 included in the final analysis. The patients had a mean age of 58.6 ± 9.66 years and a mean BMI of 29.2 ± 6.02 kg/m². There was no significant difference in mean preoperative ASES score by year for the duration of this study (2015-2019, P = .27). Worker's compensation patients had a significantly lower mean preoperative ASES score than patients with commercial or government insurance (P < .01). Spearman's rank correlations showed no relationship between ASES score and patient demographics (age, sex, BMI, race, and hand dominance) or between ASES and previous orthopedic surgery. Preoperative ASES showed a weakly positive correlation (ρ = 0.26) with 12-item short form mental component score. Multivariate linear regression showed male sex is predictive of a lower tipping point (P < .01), whereas higher BMI, African American race, and history of arthroplasty are predictive of a higher tipping point (P ≤ .02).

Conclusion

The tipping point was not demonstrated to change over time in our analysis. Male sex is predictive of a lower tipping point for arthroscopic rotator cuff repair, whereas elevated BMI, African American race, worker's compensation insurance, and prior arthroplasty are predictive of a higher tipping point. Also, better mental health function is associated with a lower tipping point.

A comparison of clinical and patient-reported outcome measures of TKR: Comparison of Asian to North American patients

BACKGROUND

Cultural differences between continents may also affect the outcome on interventions. This study compared an Asian and North American cohort of total knee replacement (TKR) patients.

QUESTIONS/PURPOSES

This study aims to compare the patient-reported outcome measures as well as a functional outcome after TKR between these two different patient populations with a different cultural societal background in two different countries.

PATIENTS AND METHODS

A retrospective study on two cohorts of 76 Asian TKR patients and 64 North American TKR patients were compared. Demographics, patient-reported outcome measures (Knee Society Score (KSS), Patient-Administered Questionnaire (PAQ), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)), knee range of motion (RoM), and radiographic component position were compared.

RESULTS

The Asian cohort had more females compared to the North American and significantly worse preoperative RoM, and worse KSS function score and PAQ pain scores. The preoperative KSS knee score and WOMAC scores were comparable between the two groups. Postoperatively, the differences in WOMAC and KSS knee scores were significant, while KSS function and PAQ were comparable between groups.

CONCLUSIONS

Even though Asian TKR patients had significantly worse preoperative scores, their postoperative outcomes were comparable to North Americans. The higher preoperative functional deficit and the higher pain levels in the Asian population might be due to cultural differences and/or socioeconomic reasons, which made Asian patients present with more severe conditions in the preoperative consultation for a possible surgical treatment compared to North Americans. More research is needed to investigate the difference between these cultural impacts on TKR outcomes.

LEVEL OF EVIDENCE

Level III/Retrospective cohort study.

Association of the 36-Item Short Form Health Survey Physical Component Summary Score With Patient Satisfaction and Improvement 2 Years After Total Knee Arthroplasty

IMPORTANCE

Increases in total knee arthroplasty (TKA) utilization rates suggest that its indications have been expanded to include patients with less severe symptoms. A recent study challenged the cost-effectiveness of TKA in this group of patients.

OBJECTIVE

To determine the association of the 36-Item Short Form Health Survey physical component summary score (SF-36 PCS) with patient satisfaction 2 years after TKA.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study reviewed registry data from 2 years of follow-up of patients who underwent unilateral TKA from January 1, 2010, to December 31, 2014, at a single-center tertiary institution in Singapore. Data were acquired on April 27, 2017, and analyzed from August 15, 2017, to December 22, 2017.

MAIN OUTCOMES AND MEASURES

Patient satisfaction and SF-36 PCS. Preoperative disability and postoperative function as measured by the SF-36 PCS were correlated with Δ (2-year end point score minus baseline score) and patient satisfaction, scored on a 6-point Likert scale, with lower scores indicating greater satisfaction.

RESULTS

Of the 6659 patients, 5234 (78.6%) were female and 5753 (86.4%) were of Chinese ethnicity. Mean (SD) age was 67.0 (7.7) years, and mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 27.7 (4.6). At 2-year follow-up, the mean (SD) SF-36 PCS score improved from 32.2 (10.1) to 48.2 (9.5) (P < .001). There were 1680 patients (25.2%) who described their satisfaction as excellent, 2574 (38.7%) very good, 1879 (28.2%) good, 382 (5.7%) fair, 96 (1.4%) poor, and 48 (0.7%) terrible. The minimal clinically important difference (change in SF-36 PCS of 10 from baseline) was met in 4515 patients (67.8%), and overall satisfaction was 97.8% (6515 patients). Covariance analysis showed significantly higher satisfaction in patients with preoperative scores of 40 to less than 50. Patients who were unlikely to meet the minimal clinically important difference compared with those who were likely to meet it (SF-36 PCS of ≥42.1 vs <42.1) had significantly higher 2-year satisfaction (mean [SD], 2.15 [0.9] vs 2.23 [1.0]; P = .009).

CONCLUSIONS AND RELEVANCE

The findings suggest that a general health score, such as SF-36, is not associated with patient satisfaction 2 years after TKA. Functional assessment, preoperative counseling, and modification of expectations appear to remain vital before TKA.

The "tipping point" for 931 elective shoulder arthroplasties

BACKGROUND

A patient with arthritis usually experiences the progression of symptoms over time. At some stage, the patient may decide that the symptoms have reached a level of severity that leads him or her to elect to proceed with joint replacement; we refer to this degree of symptom severity as the "tipping point." Our goal was to study the factors that influenced the tipping point for patients undergoing elective shoulder arthroplasty.

METHODS

We analyzed the characteristics of 931 patients undergoing shoulder arthroplasty to determine the factors affecting the tipping point as characterized by the patients' comfort and function at the time they determined their symptoms had progressed to the point when this elective surgery was merited.

RESULTS

The preoperative Simple Shoulder Test (SST) score for all patients averaged 3.6 ± 2.7. The average tipping points were different for the ream-and-run procedure (mean SST score, 5.0 ± 2.5), hemiarthroplasty (mean SST score, 3.1 ± 3.3), total shoulder arthroplasty (mean SST score, 3.0 ± 2.4), cuff tear arthropathy arthroplasty (mean SST score, 2.8 ± 2.5), and reverse total shoulder arthroplasty (mean SST score, 1.5 ± 1.8). A number of other factors were significantly associated with a higher tipping point: younger age, better health, male sex, commercial insurance, married, nonuse of narcotics, use of alcohol, and shoulder problem not related to work.

CONCLUSIONS

Analysis of the tipping point-the patients' self-assessed comfort and function at the point they decide to undergo shoulder joint replacement-provides a means by which surgeons can understand the factors influencing the indications for these procedures.

Evaluation of the Factors Affecting Concerns and Expectations of Patients Undergoing Total Knee Arthroplasty in China

Background

The aim of this study was to assess the level of concern and expectations of patients and their families of total knee arthroplasty (TKA), peri-operative procedures, postoperative rehabilitation, and outcome in a Chinese population.

Material/Methods

The study recruited 133 patients with osteoarthritis, scheduled to undergo primary elective TKA. Before surgery, the surgeon completed the Hospital for Special Surgery (HSS) Knee Score questionnaire on pain, function, range of motion (ROM), and muscle strength. There were 128 patients and 127 family members (spouses, sons, or daughters) who completed the 24-item Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questionnaire on pain, stiffness, and physical function, and also a 61-item questionnaire that included direct questions on their concerns and expectations on TKA and its outcome, using scores of: 1, not concerned; 2, somewhat concerned; 3, very concerned; and 4, extremely concerned.

Results

The five greatest pre-operative concerns for patients included the degree of postoperative mobility; the experience and expertise of their surgeon; the risk of failure of TKA; the duration of the joint implant; and their expected degree of postoperative independence. Scores for Chinese patients indicated a higher level of concern compared with Western patients. Family members were significantly more concerned than patients regarding the postoperative restoration of knee function and alleviation of pain (p=0.001), the ability to squat (p=0.049) and to kneel (p=0.039).

Conclusions

Communicating pre-operative information on TKA might result in realistic expectations for patients and their families, alleviate concerns, and improve relationships between doctors and patients.

Correlations Between Functional Knee Outcomes and Health-Related Quality of Life After Total Knee Arthroplasty in an Asian Population

BACKGROUND

Current literature evaluating postoperative outcomes after total knee arthroplasty for osteoarthritis in the Asian population is sparse. We aimed to evaluate correlations between improvements in knee outcomes vs changes in generic health-related quality of life.

METHODS

Postoperative outcomes were collected prospectively for 369 patients and compared at a 2-year follow-up using Short-Form 36 (SF-36), Knee Society Score (KSS), and Oxford Knee Score (OKS). The Spearman correlation coefficient was used to evaluate the strength of correlation between changes in knee scores (KSS and OKS) vs changes in each domain of the SF-36 scores.

RESULTS

All parameters achieved statistically significant improvements (P < .05) in postoperative scores at 2-year follow-up with the exception of general health (P = .221) component of SF-36. For KSS knee score, there was low correlation with bodily pain (0.32). For KSS function score, there was moderate correlation with physical functioning (0.57) and low correlation with role physical (0.31) and social functioning (0.36). For OKS, there was moderate correlation with physical functioning (0.61) and social functioning (0.54) and low correlation with role physical (0.38) and bodily pain (0.50). All other parameters of SF-36 showed little correlation (<0.3).

CONCLUSION

Improvements in knee-specific outcomes (KSS and OKS) after total knee arthroplasty correlate well with improvements in physical domains of health-related quality of life (SF-36) but poorly with the mental and social health domains.

Preoperative patient characteristics and outcomes of total knee arthroplasty in a multiethnic Asian population stratified by ethnicity

We aim to compare the patient profile and outcomes after TKA between the different racial groups in Singapore. Prospective data were collected from 364 patients who underwent TKA in Singapore General Hospital from January 2006 to May 2010. Patients were stratified according to ethnicity and we compared their preoperative demographic data, Short-Form 36 (SF-36), Oxford Knee (OKS) as well as Knee Society Scores (KSS). Malays were younger (62.0 ± 5.3) at time of surgery (p=0.05) and the body mass index of Chinese (27.9 ± 4.7) was lower than Malay (30.4 ± 5.0) and Indian (31.5 ± 4.5) patients (P<0.005). Malay (40.3 ± 11.0) and Indian (39.2 ± 9.3) patients had less favourable preoperative OKS than Chinese (35.9 ± 7.8) patients (P<0.05). All 3 ethnic groups achieved statistically significant improvements in outcome measures but did not differ significantly between the ethnicities.

How the gender or morphological specific TKA prosthesis improves the component fit in the Chinese population?

The purpose of this study was to evaluate how the gender specific or morphological specific total knee prostheses improve the component fit in the distal femur of the Chinese population. The data showed that the perfect fit rate of the femoral component remarkably increased in both the male and female subjects when using the gender specific (Nexgen-LPS GSF, Zimmer) or morphological specific (Advance Stature Knee, Wright Medical Technology) knee prostheses, compared to their standard counterparts. The highest femoral component perfect fit rate was achieved when both the standard and the corresponding gender or morphological specific knee prostheses were available for selection. Additionally, the percentage of the gender or morphological specific prosthesis selection in the females was significantly higher than the males.

Comparative demographics, ROM, and function after TKA in Chinese, Malays, and Indians

BACKGROUND

There is marked racial disparity in TKA use rates, demographics, and outcomes between white and Afro-Caribbean Americans. Comparative studies of ethnicity in patients undergoing TKAs have been mostly in American populations with an underrepresentation of Asian groups. It is unclear whether these disparities exist in Chinese, Malays, and Indians.

QUESTIONS/PURPOSES

We therefore determined whether (1) TKA use; (2) demographics and preoperative statuses; and (3) functional outcomes at 2 years after TKA differed among three ethnic groups, namely, Chinese, Malays, and Indians who underwent TKA.

METHODS

From our hospital joint registry we identified 5332 patients who had a primary TKA from 2004 to 2009. The cohort was stratified by race and subsequently compared for demographics, preoperative knee ROM, and deformity. At the second postoperative year we determined Knee Society scores, Oxford knee scores, and obtained SF-36 health questionnaires.

RESULTS

Six percent more Chinese patients underwent TKAs compared with Malays or Indians. Malays were operated on at a younger age with a higher body mass index. Chinese patients had more severe preoperative varus deformity. There were no major differences in joint ROM in all races. For Knee Society, Oxford knee, and SF-36 scores, Chinese patients had consistently higher preoperative and postoperative scores. Malays presented with the lowest preoperative scores but had the greatest improvement in scores at followup with postoperative scores similar to Chinese counterparts. Indians had the lowest postoperative scores and worst improvement of all

CONCLUSIONS

The variations in demographics, preoperative statuses, and subsequent postoperative outcomes between the races should be considered when comparing TKA outcome studies in Asian populations.

Cross-cultural adaptation and validation of the Oxford 12-item knee score in Japanese

INTRODUCTION

With the high incidence of knee osteoarthritis (OA) in Japan, there is a strong need not only for surgical therapies, but also for validated outcome measures. For this study, we completed cross-cultural adaptation, testing and validation of the Oxford knee score (OKS) for prospective use in national and international clinical studies involving Japanese patients.

MATERIALS AND METHODS

The Japanese version of the OKS was developed according to the standard cross-cultural adaptation guidelines. For validation, the OKS was tested on 54 patients diagnosed with OA, osteonecrosis, ligament or meniscus injury. Reliability was tested using the intraclass correlation coefficient (ICC). Internal consistency or homogeneity was assessed using Cronbach's alpha. The correlation between the Japanese OKS, WOMAC and SF-36 questionnaires was used to assess construct validity.

RESULTS

No major difficulties were encountered with the translation and pre-testing stages. For reliability and validity, the Japanese OKS was completed without any missed responses by 53 (98.15%) and 52 (96.30%) patients at the first and second distribution, respectively. The total OKS showed good reliability with an ICC of 0.85. Internal consistency was strong (Cronbach's alpha = 0.90). Strong construct validity (ICC values of 0.51-0.84) was obtained against the WOMAC and SF-36 (physical functioning, role-physical, bodily pain, and social functioning subscales) scores. Notable "ceiling" effects of the OKS were reported for 11 of the 12 questionnaire items.

CONCLUSION

The Japanese OKS has proven to be a reliable and valid instrument for the self-assessment of knee pain and function in Japanese speaking patients with knee OA and other knee complaints.

Differences of knee anthropometry between Chinese and white men and women

Whether there are differences in knee anthropometry between Asian and white knees remains unclear. Three-dimensional knee models were constructed using computed tomography or magnetic resonance imaging of healthy Chinese and white subjects. The morphologic measurements of the femur included mediolateral, anteroposterior dimensions, and aspect ratio. The tibial measurements included mediolateral, medial/lateral anteroposterior dimension, aspect ratio, and posterior slope of medial/lateral plateau. The results showed that Chinese knees were generally smaller than white knees. In addition, the femoral aspect ratio of Chinese females was significantly smaller than that of white females (1.24 ± 0.04 vs 1.28 ± 0.06). Tibial aspect ratio differences between Chinese and white males (1.82 ± 0.07 vs 1.75 ± 0.11), though significant, were likely a reflection of differences in knee size between races. These racial differences should be considered in the design of total knee arthroplasty prosthesis for Asian population.

Ethnic and gender differences in the functional disparities after primary total knee arthroplasty

BACKGROUND

The benefits of TKA have been well documented. Whether these benefits apply equally across gender and ethnic groups is unclear. Given the underuse of TKA among certain demographic groups, it is important to understand whether gender or ethnicity influence pain and function after TKA.

QUESTIONS/PURPOSES

We determined (1) the influence of race, gender, and body mass index (BMI) on primary TKA functional scores and ROM before gender-specific implants; and (2) whether comorbidities influenced ROM and functional scores.

PATIENTS AND METHODS

We reviewed all 202 patients who underwent primary TKAs in 2004. We contacted 185 of the 202 patients, including 90 African-Americans, 87 Caucasians, four Asians, and four Hispanics (55 men, 130 women). Their average age was 66 years, and average BMI was 34.4 (range, 20-55). Knee Society scores (KSS) and ROM, patient demographics, and the Charlson Comorbidity Index (CCI) were recorded. Minimum followup was 24 months (average, 29.1 months; range, 24-60.3 months).

RESULTS

African-Americans had longer delays to presentation, higher BMI, and worse 2-year KSS. Women (all races) had higher BMI and worse preoperative flexion/arc ROM. African-American women had worse final ROM and had similar final gains in ROM (postoperative minus preoperative ROM) after controlling for confounders.

CONCLUSIONS

Gender and race affected functional KSS and ROM variables. The worse results experienced by African-American women may be attributable to a longer delay to presentation. However, the scores and motion were high for all subgroups, and underuse of TKA in women and African-Americans cannot be justified based on a perception of lesser functional gains.

Gender differences in the correlation between symptom and radiographic severity in patients with knee osteoarthritis

BACKGROUND

The effects of gender on the relationship between symptom manifestations and radiographic grades of knee osteoarthritis are not well understood.

QUESTIONS/PURPOSES

We therefore determined the increments of symptom progression with regard to radiographic grades of knee osteoarthritis and asked if those increments differed by gender and whether symptom severity was differentially manifested by gender within the same grade.

METHODS

We recruited 660 community residents; 368 (56%) women and 292 (44%) men. The mean subject age was 71.5 years (range, 65-91 years). Severity of symptoms was measured using the WOMAC and SF-36 scales, and the radiographic severity using Kellgren-Lawrence grades. Incremental changes in WOMAC and SF-36 scores were compared between adjacent Kellgren-Lawrence grades separately in men and women, and in the overall population. We compared symptom severity between men and women with the same radiographic grade.

RESULTS

For the entire cohort, the mean incremental change in symptom severity was not gradual between the adjacent radiographic grades but was greater between Kellgren-Lawrence Grades 1 and 2 and Grades 2 and 3 than between Grades 0 and 1 or Grades 3 and 4. The patterns of incremental changes in symptom severity differed between men and women: women had more severe symptom progression between Kellgren-Lawrence Grades 2 and 3 and Grades 3 and 4 than men. Furthermore, women had worse mean WOMAC and SF-36 scores than men with the same radiographic grade of knee osteoarthritis.

CONCLUSIONS

These data suggest symptom progression is not gradual between adjacent radiographic grades, and for the same radiographic grade, symptoms are worse in women.

LEVEL OF EVIDENCE

Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Outcomes of total knee arthroplasty in English- versus non-English-speaking patients

PURPOSE

To compare outcomes of total knee arthroplasty (TKA) in English- versus non-English-speaking patients.

METHODS

193 women and 85 men (mean age, 72 years) underwent 117 left and 161 right primary TKAs. 237 and 41 patients were English and non-English speaking, respectively. Interpretation was provided. Pre- and post-operative functional outcomes were measured using the International Knee Society (IKS) score.

RESULTS

Most non-English-speaking patients were female (38 vs 3 of 41, p<0.001). The mean body mass index of non-English-speaking patients was significantly higher (34 vs 31 kg/m[2], p=0.003). 14 foreign languages were spoken among the 41 non-English-speaking patients, of which Greek and Italian were the most common. Non-English-speaking patients had significantly worse IKS scores both preoperatively and at the 12-month follow-up. The proportions of poor postoperative IKS scores were significantly higher in non-English-speaking patients (58% vs 27%, p<0.001), in whom pain was also significantly worse (p=0.017). In a multiple logistic regression analysis, being non-English speaking was the only predictor of poor functional outcome at the 12-month follow-up (odds ratio=2.77, confidence interval=1.25-6.14, p=0.012).

CONCLUSION

The non-English-speaking background of a patient is a predictor of less favourable functional outcome after TKA.

Analysis of biomechanical effect of stem-end design in revision TKA using Digital Korean model

BACKGROUND

The stem-end pain after revision total knee arthroplasty has been clinically reported around the diaphyseal region of the tibia, and the stem-end design has been recognized as one of the causes of the stem-end pain. But there are few reports about the biomechanical characteristics of different stem-end designs on revision total knee arthroplasty. The objective of this study is to investigate the biomechanical effect of the stem-end design in revision total knee arthroplasty.

METHODS

Three-dimensional finite element models of a tibia and implants for revision total knee arthroplasty with various stem-end design parameters were developed. The tibia model was chosen from 50 male cadavers to represent the standard Korean male. The contact pressures and von Mises stresses around the stem-end were calculated under axial loading.

FINDINGS

The longer stem length, the bigger stem diameter, the stronger press-fit, and no slot shape increased both peak contact pressures and von Mises stresses. The location of peak contact pressures coincided with the location of stem-end pain reported in clinical studies.

INTERPRETATION

Different stem-end designs altered the contact pressures or stress concentrations to the tip of the stem. The location of peak contact pressures or von Mises stresses suggested there may be a biomechanical factor to transfer load or generate stress concentration at the location of the stem-end pain in the diaphysis.