The Impact of Race, Insurance, and Socioeconomic Factors on Pediatric Knee Injuries.

Disparities persist in pediatric sports medicine along the lines of race, ethnicity, insurance status, and other demographic factors. In the context of knee injuries such as anterior cruciate ligament (ACL) ruptures, meniscus tears, and tibial spine fractures, these inequalities affect evaluation, treatment, and outcomes. The long-term effects can be far-reaching, including sports and physical activity participation, comorbid chronic disease, and socio-emotional health. Further research is needed to more concretely identify the etiology of these disparities so that effective, equitable care is provided for all children.

Racial variations in knee joint laxity: A comparative study of the Jordanian Arab and Malay populations.

BACKGROUND: A high incidence of joint laxity has been reported among Asians compared with Western populations, but clear differences between more specific ethnic populations have not been established. This study aimed to determine the average knee laxity in the Malaysian and Jordanian populations. METHODS: Jordanian and Malaysian medical students from our institution were invited to participate in the study. General demographic data and factors affecting joint laxity were obtained from each participant using a printed questionnaire. Both knees were examined using the anterior drawer test while in 90° of flexion. Knee laxity was measured by three separate independent investigators through a knee laxity tester. RESULTS: One hundred and eighty-six participants (95 females) were enrolled in the study. Among them, 108 Malaysians participated. The Jordanians had significantly higher knee laxity in both knees compared with the Malaysians. The mean average right knee laxity for Jordanians was 2.98 mm vs. 2.72 mm for Malaysians (P = 0.005). Similarly, the mean average left knee laxity for Jordanians was 2.95 mm, while for Malaysians, it was 2.62 mm (P = 0.0001). Furthermore, smokers had significantly more laxity in both knees. After performing a multivariate linear regression analysis for all factors, race was the only independent factor that affected knee laxity in both knees. CONCLUSIONS: Race is directly associated with knee laxity. Jordanians tend to have more laxity in knee joints compared with Malaysians. Larger multi-center and genetic studies are recommended to establish the racial differences between different ethnic groups.

Clinical Outcomes, Return to Sports, and Patient Satisfaction After Anterior Cruciate Ligament Reconstruction in Young and Middle-Aged Patients in an Asian Population-A 2-Year Follow-up Study.

PURPOSE: To compare the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction in young and middle-aged Asians. METHODS: A retrospective study was performed using prospectively collected data from a tertiary institution ACL registry. All Asian patients with ACL tears who underwent primary arthroscopic ACL reconstruction by a single surgeon between 2008 and 2014, with minimum 2-year follow-up, were included. Patients with previous knee surgery or multiligamentous knee injuries were excluded. Two groups were formed: young patients (YP) (age <30) and middle-aged patients (MP) (age >40). They were compared preoperatively and 6 months, 1 year, and 2 years postoperatively for demographics, knee range of motion, anterior laxity, Tegner level, Lysholm and International Knee Documentation Committee grade, ability to return to preinjury level of activity, and patient satisfaction. RESULTS: YP (n = 84) and MP (n = 22) had differences in mean age (YP = 23.1 years, range 18-29 years; MP = 46.4 years, range 41-59 years, P < .001), preinjury Tegner level (YP = 7.4, MP = 6.4, P = .005), and preoperative Lysholm scores (YP = 65.3, MP = 53.0, P = .034). The incidence of meniscal and chondral injuries was similar. Two years postoperatively, both groups had comparable knee range of motion and anterior laxity. The Tegner score was different (YP = 6.3, MP = 5.2, P = .028), but the proportion of patients returning to preinjury Tegner level (YP = 45.2%, MP = 46.9%, P = .812), Lysholm scores (YP = 92.5, MP = 93.8, P = .794), proportion of patients with knees rated International Knee Documentation Committee A/B (YP = 77.4%, MP = 81.8%, P = .777), and satisfaction levels (YP = 98.5%, MP = 94.1%, P = .370) were similar. There were no graft ruptures or reoperations. CONCLUSIONS: In an Asian, predominantly male population, the clinical outcomes of arthroscopic ACL reconstruction in YP and MP are equally good at 2-year follow-up. MP can benefit as much as younger patients from ACL reconstruction in terms of restoration of knee function and return to preinjury activity level, are equally satisfied with outcomes, and should not be excluded from surgery on the basis of age alone. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Arabic translation, cultural adaptation, and validation study of Knee Outcome Survey: Activities of Daily Living Scale (KOS-ADLS).

Knee complaints and their accompanying functional impairments are frequent problems encountered by healthcare practitioners worldwide. Plenty of functional scoring systems were developed and validated to give a relative estimation about the knee function. Despite the wide geographic distribution of Arabic language in the Middle East and North Africa, it is rare to find a validated knee function scale in Arabic. The present study is aimed to translate, validate, and culturally adjust the Knee Outcome Survey: Activities of Daily Living Scale (KOS-ADLS) into Arabic language for future use among Arabic-speaking patients. Permission for translation was obtained from the copyrights holder. Two different teams of high-level clinical and linguistic expertise conducted translation process blindly. Forward-backward translation technique was implemented to ensure preservation of the main conceptual content. Main study consisted of 280 subjects. Reliability was examined by test-retest pilot study. Visual Analogue Scale (VAS), Get Up and Go (GUG) Test, Ascending/Descending Stairs (A/D Stairs), and Subjective Assessment of Function (SAF) were conducted concurrently to show the validity of Arabic KOS-ADLS statistically in relation to these scales. Final translated version showed no significant discrepancies. Minor adaptive adjustment was required to fit Arabian cultural background. Internal consistency was favourable (Cronbach's alpha 0.90). Patients' scoring on Arabic KOS-ADLS appeared relatively consistent with their scoring on VAS, GUG, A/D Stairs, and SAF. A significant linear relationship was demonstrated between SAF and total KOS-ADLS scores on regression analysis (adj. R 2 = 0.548). Arabic KOS-ADLS, as its English counterpart, was found to be a simple, valid, and useful instrument for knee function evaluation. Arabic version of KOS-ADLS represents a promising candidate for unconditional use among Arabic-speaking patients with knee complaints.

Translation and validation of the simplified Chinese new Knee Society Scoring System.

BACKGROUND: The NKSS has recently been translated into Dutch version. The reliability and validity were also assessed. However, there is no Simplified Chinese version of New Society Knee Scoring System (SC-NKSS) for Chinese population. METHODS: The SC-NKSS was translated from the original English version following international guidelines. All patients undergoing total knee arthroplasty (TKA) between September 2012 and September 2013 were invited to participate in this study. Finally, a total of 105 did so. Patients (preoperative and postoperative) completed the Chinese version of NKSS, Oxford Knee Score (OKS), the Medical Outcomes General Health Survey (SF-36) and Visual analog scale (VAS). Psychometric testing of reliability, construct validity, content validity were conducted. RESULTS: All the 105 participants completed the questionnaires and no floor or ceiling effects were checked. Internal consistency was excellent with Cronbach's alpha coefficient ranging from 0.71 to 0.85. Test-retest reliability was satisfactory with an intraclass correlation coefficient of 0.92 (95%confidence interval, 0.86-0.95). Construct validity was demonstrated to correlate well with the Chinese version of OKS (r = -0.78; p < 0.01), VAS (r = -0.70; p < 0.01), Physical Function (PF) (r = 0.74; p < 0.01), Body Pain (BP) (r = 0.63; p < 0.01) and General Health (GH) (r = 0.51; p < 0.01) of SF-36 domains. CONCLUSION: The SC-NKSS was well accepted and demonstrated acceptable psychometric properties in mainland China.

Risk factors associated with revision and contralateral anterior cruciate ligament reconstructions in the Kaiser Permanente ACLR registry.

BACKGROUND: Patients generally choose to undergo anterior cruciate ligament reconstruction (ACLR) to return to their active lifestyles. However, returning to their previous activity level may result in a retear of their reconstructed knee or an injury to their contralateral anterior cruciate ligament (CACL). PURPOSE: To determine the risk factors associated with revision ACLR and contralateral ACLR (CACLR), compare the survival of the reconstructed ACL with the CACL, and determine how the risk factors associated with revision ACLR compare with those for CACLR. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective cohort study of prospectively collected data from the Kaiser Permanente ACLR registry between February 1, 2005, and September 30, 2012, was conducted. Primary ACLR cases without history of contralateral knee ACL injury were included. The study endpoints included revision ACLR and CACLR. Graft type (bone-patellar tendon-bone [BPTB] autograft, hamstring autograft, and allograft) was the main exposure of interest, and patient characteristics were evaluated as risk factors for revision ACLR and CACLR. Survival analyses were conducted. RESULTS: A total of 17,436 ACLRs were evaluated. The median age was 27.2 years (interquartile range, 18.7-37.7 years), and 64% were males. The 5-year survival for index ACLR was 95.1% (95% CI, 94.5%-95.6%), and for CACL it was 95.8% (95% CI, 95.2%-96.3%). Overall, the cohort had a mean of 2.4 ± 1.7 years of follow-up; 18.2% were lost to follow-up. There were fewer CACLRs per 100 years of observation (0.83) than there were revision ACLRs (1.05) during the study period (P < .001). There was a statistically significant difference in the density of revision ACLR and CACL in BPTB autografts (0.74 vs 1.06, respectively; P = .010), hamstring autografts (1.07 vs 0.81; P = .042), and allografts (1.26 vs 0.67; P < .001). The risk factors for revision ACLR and contralateral surgery were different (P < .05). After adjusting for covariates, factors associated with higher risk of revision ACLR were as follows: allografts, hamstring autografts, male sex, younger age, lower body mass index (BMI), and being white as opposed to black. Factors associated with higher risk of CACLR were as follows: younger age, female sex, and lower BMI. CONCLUSION: The 5-year revision-free and CACLR-free survival rate in this study was 95.1% and 95.8%, respectively. Allografts and hamstring autografts had a higher risk of revision ACLR surgery, and BPTB autografts had a higher risk of CACLR. Males were found to have a higher risk of revision ACLR, and females had a higher risk of CACLR. Increasing age and increasing BMI decreased the risk of both revision and CACLR.

Comprehensive assessment of tibial plateau morphology in total knee arthroplasty: Influence of shape and size on anthropometric variability.

Better understanding of proximal tibia morphology can lead to improvements in total knee arthroplasty (TKA) through development of tibial tray families that adequately reflect the diversity of global anatomy using an appropriate number of components. We quantified variations in proximal tibial morphology at the TKA level and characterized differences attributable to gender and ethnicity. Virtual TKA was performed on digital models of 347 tibiae, spanning both genders and multiple ethnicities. The geometry of the resection profile was quantified using both a comprehensive set of morphological measurements (reflecting size and shape) and principal component analysis (PCA). The dominant statistical modes of variation were associated primarily with size (plateau dimensions, radii, and area), with lesser contributions associated with asymmetry and aspect ratios. Medial and lateral AP dimensions were strongly correlated with plateau ML width, with minimal differences in correlations due to gender or ethnicity. In conclusion, clinically relevant differences in proximal tibia morphology at the level of TKA resections across genders and multiple ethnicities can be attributed largely to variations in overall proximal tibial size, not gender- or ethnic-specific shape variations.

Distal femur rotation relates to joint obliquity in ACL-deficient Chinese.

BACKGROUND: The lower limb osteometry of Chinese differs from that of whites. The joint line of the knee in the coronal plane in Chinese is more medially inclined and the posterior condylar angle of the distal femur in the axial plane is larger. However, it is unclear whether there is any direct association between the coronal plane and axial plane osteometry. QUESTIONS/PURPOSES: We asked whether the joint line obliquity of the knee is related to the posterior condylar angle of the distal femur in young Chinese subjects. METHODS: Ninety-nine young Chinese patients with anterior cruciate ligament injuries were recruited. The lower limb alignment and joint line obliquity were measured using standing long radiographs of the whole lower limb. The rotational alignment of the distal femur was assessed in the axial cuts of the MRI. RESULTS: The distal femur rotational alignment was associated with the obliquity of the knee in Chinese. The posterior condylar angle was 5° ± 2°. The knee was 5° ± 3° medially inclined. CONCLUSIONS: The joint line of the knee in a group of young Chinese patients was more medially inclined than that of whites. The posterior condylar angle of the distal femur was larger. The presence of an association between distal femur rotational alignment and joint line obliquity in this group of young Chinese patients suggests a possible developmental cause explaining the difference in osteometry between races.

Risk factors for medial meniscus posterior root tear.

BACKGROUND: Medial meniscus posterior root tears (MMPRT) have a different clinical effect from other types of meniscal tears. These tears are very common among Asian people and may be related to the frequent use of postures such as the lotus position or squatting. PURPOSE: The present study was designed to identify the risk factors for MMPRT among an Asian sample. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: An observational study was performed of 476 consecutive patients undergoing an arthroscopic procedure on their medial meniscus from January 2010 to December 2010. One hundred four patients had MMPRT (group 1), and the other patients had other types of medial meniscal tears (group 2). Demographic characteristics (age, sex, body mass index [BMI]), radiographic features (mechanical axis angle, tibia vara angle, tibial slope angle, Kellgren-Lawrence grade [KLG]), and environmental factors (occupation, trauma history, sports activity level, table use or not, bed use or not-variables that are representative of the oriental lifestyle of lotus position and squatting) were surveyed. We assessed the relation of these risk factors to the type of meniscal tear (group 1 or 2). RESULTS: In group 1, there were 7 male and 97 female patients, with an average age of 58.2 years (range, 39-78 years) and BMI of 26.7 ± 3.4 kg/m2. In group 2, there were 136 male and 236 female patients (P < .01 compared with group 1), with an average age of 54.3 years (range, 17-77 years; P < .01) and a BMI of 24.9 ± 3.1 kg/m2 (P < .01). With regard to radiographic features, the mechanical axis angle demonstrated a significantly increased varus alignment in group 1 (4.5° ± 3.4°) compared with group 2 (2.4° ± 2.7°; P < .01), and the KLG was 1.4 ± 0.8 in group 1 and 0.9 ± 0.6 in group 2 (P < .01). Environmental factors showed no differences in occupation, table use or not, and bed use or not, except sports activity level. There were 41 patients (42.7%) in group 1 and 77 patients (20.6%) in group 2 who did not participate in any recreational activity (P < .01). Multiple logistic regression analysis showed that female sex was associated with a 5.9-fold increase in risk (95% confidence interval [CI], 2.138-16.575), a varus mechanical axis angle with a 3.3-fold increase (95% CI, 1.492-7.153), a BMI more than 30 kg/m2 with a 4.9-fold increase (95% CI, 1.160-20.955), and lower sports activity level with a 2.7-fold increase (95% CI, 1.011-7.163) for MMPRT. CONCLUSION: Persons with MMPRT had significantly increased age, female sex predominance, higher BMI, increased KLG, greater varus mechanical axis angle, and lower sports activity level compared with persons with other types of meniscal tear. After adjusting for other factors, sex, BMI, mechanical axis angle, and lower sports activity level remained strong determinants of MMPRT. Interestingly, oriental postural positions including the lotus position and squatting showed no contribution to increased risk of MMPRT. This suggests that intrinsic risk factors (similar to those that predispose to osteoarthritis) predispose to MMPRT.

Prediction of the graft size of 4-stranded semitendinosus tendon and 4-stranded gracilis tendon for anterior cruciate ligament reconstruction: a Chinese Han patient study.

BACKGROUND: Little information is available regarding parameters that would enable a surgeon to predict the size and length of 4-stranded semitendinosus (ST) and 4-stranded gracilis tendon (GT) grafts. PURPOSE: To evaluate whether certain preoperative anthropometric data enable prediction of the size of 4-stranded ST and GT autograft for anterior cruciate ligament (ACL) reconstruction. STUDY DESIGN: Cohort study (prevalence); Level of evidence, 2. METHODS: This study involved 235 Chinese Han patients who underwent double-bundle ACL reconstruction with 4-stranded autogenous ST and GT grafts. Preoperatively, the authors recorded height, weight, body mass index (BMI), gender, age, and sports activity. During surgery, the usable length of the ST and GT and the diameter of the 4-stranded grafts made of ST and GT were measured. Multiple regression analysis was used to determine relationships between anthropometric measurements and the length and diameter of intraoperatively measured ST and GT grafts. RESULTS: Strongest correlations for ST and GT length and GT graft diameter were height and weight. The strongest correlations for ST graft diameter were gender and weight. Body mass index had only moderate correlations with ST and GT graft size. Self-reported activity level was not correlated. Women had significantly smaller GT and ST graft diameters and shorter tendon lengths than did men. Semitendinosus graft size was significantly larger and longer than was the GT graft (7.4 ± 0.7 mm vs 5.9 ± 0.6 mm and 279.9 ± 20.8 mm vs 251.5 ± 20.8 mm, respectively). Simple regression analysis demonstrated that height, weight, and BMI can be used to predict ST and GT autograft length and diameter. CONCLUSION: Several preoperative anthropometric measurements showed correlation with the length of the ST and GT and diameter of 4-stranded ST and GT grafts. The current data may provide surgeons with important preoperative information about size of ST and GT grafts and would be useful for patient counseling and alternative graft source planning.

Cross-cultural differences in knee functional status outcomes in a polyglot society represented true disparities not biased by differential item functioning.

BACKGROUND: Comparative effectiveness research across cultures requires unbiased measures that accurately detect clinical differences between patient groups. OBJECTIVE: The purpose of this study was to assess the presence and impact of differential item functioning (DIF) in knee functional status (FS) items administered using computerized adaptive testing (CAT) as a possible cause for observed differences in outcomes between 2 cultural patient groups in a polyglot society. DESIGN: This study was a secondary analysis of prospectively collected data. METHODS: We evaluated data from 9,134 patients with knee impairments from outpatient physical therapy clinics in Israel. Items were analyzed for DIF related to sex, age, symptom acuity, surgical history, exercise history, and language used to complete the functional survey (Hebrew versus Russian). RESULTS: Several items exhibited DIF, but unadjusted FS estimates and FS estimates that accounted for DIF were essentially equal (intraclass correlation coefficient [2,1]>.999). No individual patient had a difference between unadjusted and adjusted FS estimates as large as the median standard error of the unadjusted estimates. Differences between groups defined by any of the covariates considered were essentially unchanged when using adjusted instead of unadjusted FS estimates. The greatest group-level impact was <0.3% of 1 standard deviation of the unadjusted FS estimates. LIMITATIONS: Complete data where patients answered all items in the scale would have been preferred for DIF analysis, but only CAT data were available. CONCLUSIONS: Differences in FS outcomes between groups of patients with knee impairments who answered the knee CAT in Hebrew or Russian in Israel most likely reflected true differences that may reflect societal disparities in this health outcome.

Risk factors for occupational knee related disability among enlisted women in the US Army.

AIMS: To identify sociodemographic and occupational determinants of knee related disability discharge from the US Army among enlisted women, and to investigate effect modification. METHODS: A case-control study of 692 cases of knee related disability discharge and 2080 incidence density matched controls nested within the population of all 244 000 enlisted women on active duty in the US Army, 1980-97. We used logistic regression to identify determinants of disability, stratified to explore effect modification by demographic and work characteristics. RESULTS: The risk of disability discharge was twice as high (odds ratio (OR) 2.4, 95% confidence interval (CI): 1.71 to 3.47) for the oldest (33-60 years) versus the youngest (17-21 years) women. Non-whites had lower risk than whites (OR 0.5, 95% CI: 0.41 to 0.60), as did married (OR 0.7, 95% CI: 0.54 to 0.81) relative to non-married women. Those of lower rank (pay grades E1-E3) were at five times the risk of disability discharge compared to those of higher ranks (pay grades E4-E9, OR 5.0, 95% CI: 2.86 to 8.33), while ORs were highest for those with longer duration of service compared to women on active duty for a year or less (OR 1.4, 95% CI: 0.8 to 2.55 after 12 years). Race modified several effects, including that of rank. Age, duration of service, and pay grade were too highly correlated to draw firm conclusions about their independent modifying effects on risk of disability discharge from the Army. CONCLUSIONS: Sociodemographic factors had larger effects than occupational characteristics on risk of knee related disability discharge from the US Army. Interactions suggest subgroups at differing risk levels that might be targeted for more detailed investigations.

Athletic knee injuries. Similarities and differences between Asian and Western experience.

The pattern and prevalence of knee injuries among athletes are different in Asia, Europe, and North America because of factors such as the different sporting cultures of the regions and the type of favorite sports. Sampling and data bias and the variable levels of diffusion of sports in the different parts of the world also are responsible for the variation. In this review, the knee emerges as the most commonly injured part of the body; such injuries present significant problems of mechanical block or instability that may compromise athletic performance. Sports specific injuries are delineated, and specific groups, such as children and adolescents, female, and master athletes, are reviewed in light of the characteristic patterns of knee injuries. Differences in the patients' attitude, health care systems, and consultations of traditional medical practitioners produce major differences in management styles. However, it is encouraging to find a concerted effort on all continents in the search for a better understanding of knee injuries and a more satisfactory coordination between clinical and basic science research in this field.