Obesity is associated with greater valgus knee alignment in pubertal children, and higher body mass index is associated with greater variability in knee alignment in girls

Factors predicting lower limb alignment after Oxford medial unicompartmental knee arthroplasty

This study aimed to identify the factors affecting hip-knee-ankle (HKA) angle following Oxford medial unicompartmental knee arthroplasty (MUKA). A retrospective analysis of 200 patients who underwent Oxford MUKA from June 2018 to October 2020 was conducted. Univariate and multivariate analyses were performed to investigate the impact of surgical and radiographic characteristics on the postoperative HKA angle. The mean HKA angle was 9.5 ± 4.3° before surgery and 3.6 ± 3.7° after surgery (p < 0.001). The postoperative HKA angle significantly correlated with the preoperative HKA angle, bearing size, tibial component alignment angle, and BMI (r = 0.71, p < 0.001; r =  - 0.24, p = 0.001; r = 0.21, p = 0.004; r =  - 0.18, p = 0.011). Multiple linear regression analysis revealed that the preoperative HKA angle (β = 0.68, p < 0.001), bearing size (β =  - 0.31, p < 0.001), tibial component alignment angle (β = 0.14, p = 0.003), and BMI (β =  - 0.09, p = 0.047) significantly affected the postoperative HKA angle. In conclusion, larger preoperative varus deformity, smaller bearing size, greater varus alignment of the tibial component, and lower BMI lead to greater postoperative varus alignment of the lower limb in Oxford MUKA. With this concept, surgeons can more accurately predict postoperative lower limb alignment and avoid malalignment in Oxford MUKA.

Coronal-plane leg alignment in adolescence and the effects of activity: A full leg length MRI study

The aim of this study was to explore the association between developing coronal-plane leg alignment and activity levels during adolescence. We performed a cross-sectional cohort study with individuals from soccer club academies and an age-matched control population. Outcome measures were the hip knee angle (HKA), medial proximal tibial physeal angle (MPTPhyA), lateral distal femoral physeal angle (LDFPhyA) on full leg length magnetic reasonance imagine scans, and the physical activity questionnaire (PAQ) score. The cohort comprised 57 elite male soccer players, 34 male and 34 female controls aged 11-21 years. Mean HKA became more varus with age, with little change after 16 years or skeletal maturity. Skeletally mature elite male soccer players were significantly more varus than male controls with a HKA 2.28° less than male controls (p < 0.001). Skeletally mature male controls had a HKA 1.34° less than female controls (p < 0.001). A negative correlation existed between HKA and PAQ score (coefficient -0.24, p = 0.029). A positive correlation existed between HKA and MPTPhyA (coefficient 0.32, p = 0.008). In conclusion, high activity levels during adolescence are associated with the development of varus leg alignment. Mean HKA becomes more varus with age until skeletal maturity. The development of varus alignment may represent a physiological adaptation to load at the proximal tibial physis. Clinical Significance: A time period may exist for intervention before the development of varus leg alignment in young athletes, such as training load modification or proximal tibial morphology monitoring.

The Impact of Childhood Obesity on Joint Alignment: A Systematic Review and Meta-Analysis

OBJECTIVE

It has been suggested that overweight/obesity (OW/OB) impairs the normal alignment of children and adolescents' musculoskeletal system. However, to date, no study has systematically reviewed or quantified the effect of OW/OB on the development of joint malalignments in children and adolescents. The purpose of this study was to systematically review the association between OW/OB and joint alignment in children and adolescents and to quantify the evidence on whether children and adolescents with OW/OB have a higher risk of developing joint malalignments than their peers of normal weight.

METHODS

PubMed and Web of Science databases were systematically searched from inception to March 9, 2020. Studies investigating the association between OW/OB and joint alignment in children and adolescents were selected. Nonoriginal articles, participants with movement pattern diseases, and adolescents studied while pregnant were excluded. Two independent reviewers conducted the study selection and data extraction. Qualitative synthesis of evidence and random effect meta-analyses (risk ratio [RR]) were performed.

RESULTS

Seventy-three studies (5 longitudinal and 68 cross-sectional) met the inclusion criteria involving 1,757,107 children and adolescents. There was consistent evidence supporting associations of OW/OB with rounded shoulder, lumbar hyperlordosis, genu valgum, and flatfoot. Our meta-analysis showed that children and adolescents with OW/OB had a significantly higher risk of lumbar hyperlordosis (RR = 1.41), genu valgum (RR = 5.92), flatfoot (RR = 1.49), and any joint malalignment (RR = 1.68) when compared with their peers of normal weight. The presence of genu valgum and flatfoot were the most robust results.

CONCLUSION

Based on these findings, OW/OB is associated with the presence of joint malalignments in children and adolescents.

IMPACT

This is the first study that has systematically reviewed the effect of OW/OB on the development of joint malalignments in children and adolescents.

Obesity and Meniscal Transplant Failure: A Retrospective Cohort Study

The purpose of this study was to analyze the effect of obesity and other clinical factors on the outcome of meniscal allograft transplantation (MAT) with transosseous fixation. A retrospective cohort study was performed on patients who underwent a MAT between 2002 and 2017. All the participants had a minimum follow-up period of 24 months. The variables assessed were age at the time of the transplant, side, sex, transplanted meniscus (lateral/medial), body mass index (BMI), smoking status, and previous surgeries. Lysholm, Tegner, and International Knee Documentation Committee (IKDC) test outcomes, and patient satisfaction were recorded. Image assessment was performed using plain standing X-rays and a follow-up magnetic resonance imaging scan. Thirty-five patients fulfilled the inclusion criteria. The mean follow-up time was of 75.7 standard deviation (SD) 43.4 months. Patients with a BMI ≥ 30 underwent medial meniscal transplants (88.9 vs. 42.3%, p = 0.022, respectively) more frequently. Obese patients had a significantly lower IKDC (48.6 SD 19.9 vs. 61.7 SD 13.1, p = 0.038, power: 57.5%) and Lysholm (60.3 SD 19.2 vs. 79.4 SD 14.3, p = 0.004, power: 88.7%) scores compared with nonobese patients. The satisfaction and Tegner scores were also lower in obese patients (55.6 vs. 80.7%, p = 0.136, and 2.8 SD 1.0 vs. 4.0 SD 1.9, p = 0.104, respectively); however, these differences were not statistically significant. Obese patients had higher rates of meniscal transplant failure compared with nonobese patients (adjusted hazard ratio: 11.8 [95% confidence interval: 1.5-91.4]). No differences were observed between obese and nonobese patients regarding age, sex, side, smoking status, and follow-up time. In this study, a BMI ≥ 30 kg/m² resulted in higher MAT failure rates. Nonobese patients had better knee functional results compared with obese individuals.

The Prevalence of Genu Varum and Genu Valgum in Overweight and Obese Patients: Assessing the Relationship between Body Mass Index and Knee Angular Deformities

BACKGROUND

Recent studies have shown evidence of a relationship between overweight and obesity with skeletal abnormalities, especially angular knee disorders.

AIM OF THE STUDY

To reveal causal relationship between obesity and skeletal abnormalities.

METHODS

This study was performed on 280 overweight or obese patients (with BMI > 25kg/m2) who referred to Rasoul Akram hospital in Tehran between 2017 and 2018. Several non-radiographic methods including measuring Q angle, inter-malleoli distance and distance between two knees were used to determine genu varum and genu valgum.  BMI was also calculated by dividing the weight by the square of the height.

RESULTS

The prevalence of genu varumand genu valgum was 8.6% and 10.0% respectively. There was a significant adverse correlation between the Q angle and BMI. The mean BMI in patients with and without genu varum was 39.07 ± 6.41 kg/m2 and 42.1 ± 2.26 kg/m2, respectively, which was significantly lower in the genuvarum group (P = 0.008). Also, the mean BMI in patients with and without genu valgum was 43.39 ± 3.33 kg/m2 and 41.58 ± 4.61  kg/m2, respectively, which was significantly higher in the genuvalgum group (P = 0.044). Also, there was a direct correlation between BMI of patients with inter-malleoli distance and inverse correlation between BMI and two knees distance.

CONCLUSION

There is a strong and significant relationship between incidence of obesity and genu valgum; therefore, the prevalence of this deformity in obese individuals is predictable. Also, the lower incidence of genu varum in obese people is predictable in our society.

Preoperative valgus deformity has twice the risk of failure as compared to varus deformity after total knee arthroplasty

PURPOSE

The aim of this study was to assess whether preoperative valgus or varus deformity affected survivorship after total knee arthroplasty (TKA) and to quantify the risk factors for implant failure in a registry-based population.

METHODS

The Emilia-Romagna Registry of Prosthetic Orthopedic Implants was examined regarding TKAs performed on patients with a preoperative diagnosis of valgus or varus deformity. Demographics, implant characteristic and survivorships were investigated and compared. A total of 2327 TKA procedures performed from 2000 to 2016 were included in the study. Six hundred and forty primary TKAs with a diagnosis of valgus deformity were evaluated with a median follow-up of 3.3 years; 1687 primary TKAs with a diagnosis of varus deformity were evaluated with a median follow-up of 2.5 years.

RESULTS

Bi-compartmental, cemented posterior stabilised fixed-bearing implants were preferred. For both diagnoses, the implant survivorship rate was greater than 98% in the first year. However, the survival curve of the TKAs implanted for valgus deformity showed a greater slope in the first 3 years as compared to the survival curve of those implanted for varus deformity. Valgus deformity had a 2.1-fold higher risk for revision as compared with varus deformity. Infection was a major cause of implant failure in TKAs for varus deformity, 9/24 (37.5%), while its incidence was lower for valgus deformity, 1/21 (4.8%).

CONCLUSIONS

Preoperative valgus alignment showed a twofold risk of failure as compared to varus alignment after TKA. This should be considered in daily practice, and surgeons are called on to pay more attention when performing TKAs on such patients. Prospective randomised controlled trials are, therefore, necessary to better understand the role of preoperative coronal knee deformity in implant failure.

LEVEL OF EVIDENCE

Prognostic study, level III.

Idiopathic Genu Valgum and Its Association With Obesity in Children and Adolescents

BACKGROUND

Obesity as a cause of lower extremity deformity in children has been well established. This deformity is most often seen as tibia vara, however, at our institution we have observed more obese children and adolescents over age 7 years with excessive or progressive idiopathic genu valgum. Our hypothesis is that children with idiopathic genu valgum have high rates of obesity which impact the severity of their disease.

METHODS

Retrospective review of existing data was performed on 66 consecutive children/112 limbs over age 7 years with idiopathic genu valgum, seen from 2010 to 2013. Children with known metabolic or skeletal disease were excluded. Genu valgum was defined as mechanical axis in zone II or III and mechanical tibiofemoral angle ≥4 degrees on standing anteroposterior radiograph of the lower extremities. Body mass index (BMI) was calculated and classified by Center for Disease Control percentiles. Skeletal maturation was rated by closure of pelvic and peri-genu physes. Severity of genu valgum was also assessed by femoral and tibial mechanical axes and the mechanical axis deviation.

RESULTS

Mean patient age was 12.2±2.2 years. 47% of patients had BMI≥30 and 71% were categorized as obese (>95th percentile). No sex differences were identified. Skeletal maturation explained 25% of the variance in the mechanical axis deviation and 22% of the mechanical tibiofemoral angle. BMI predicted 9.8% of the tibial valgus. Because of its skewed distribution, BMI percentile was a less useful parameter for assessment.

CONCLUSIONS

The 71% obesity rate found in our children with idiopathic genu valgum is significantly higher than the normal population. Higher BMI is associated with more tibial valgum but skeletal maturation was the main predictor of overall valgus severity. This suggests that obesity may play a role in the etiology of idiopathic genu valgum which progresses with skeletal maturation, thereby increasing the risk of osteoarthritis in adulthood.

LEVEL OF EVIDENCE

Level III.

Relationship between lower-extremity defects and body mass among polish children: a cross-sectional study

Background

Lower extremity defects in healthy children raises interest of researchers as confirmed by numerous published original and review articles. The relationship between lower extremity postural defects and body mass are unclear as published data are inconclusive. The aim of the present cross-sectional study was to analyse the prevalence of lower extremity defects in a large group of 8- to 12-year-old children; and further to assess the probability of defects associated with values of body mass variables.

Methods

The study included prospective anthropometric measurements data of 6992 children (3476 boys and 3516 girls) from Gdansk (Northern Poland). Standard screening test used in Poland for assessment of lower limb defects were used (intermalleolar or intercondylar distance for knee alignment, linear vertical compass for valgus heel, computer podoscope or classical footprint and measuring the Sztriter-Godunow index for flatfeet). Body mass was assessed with local centile charts and IOTF cutoffs. Prevalence of postural defects was compared with an aid of Pearson’s chi-squared test and Fisher’s exact test. Probability of lower extremities postural defect was estimated on the basis of logistic regression analysis, and expressed as an odds ratio (OR) and its 95.0% CI.

Results

The study demonstrated that cumulative prevalence of lower extremity defects (31.5%) was lower than reported in most published studies, most common defects were valgus heel (21.8%) and valgus knee (14.5%). Boys were significantly more frequently diagnosed with lower limb defects overall (p < 0.001), as well as with varus knee, valgus heel, flatfoot of any degree. Limb defects were found in 90,2% of obese children, 25,7% of normal weight and 15,1% of underweight children.

Conclusions

Prevalence of some lower extremities defects seems to be sex specific. Prevalence varied across body weight categories and was rising with the increase of BMI. Increased body mass is correlated with a higher risk of developing lower extremity postural defects in children.

Diagnosis, treatment and prevention of pediatric obesity: consensus position statement of the Italian Society for Pediatric Endocrinology and Diabetology and the Italian Society of Pediatrics

The Italian Consensus Position Statement on Diagnosis, Treatment and Prevention of Obesity in Children and Adolescents integrates and updates the previous guidelines to deliver an evidence based approach to the disease. The following areas were reviewed: (1) obesity definition and causes of secondary obesity; (2) physical and psychosocial comorbidities; (3) treatment and care settings; (4) prevention.The main novelties deriving from the Italian experience lie in the definition, screening of the cardiometabolic and hepatic risk factors and the endorsement of a staged approach to treatment. The evidence based efficacy of behavioral intervention versus pharmacological or surgical treatments is reported. Lastly, the prevention by promoting healthful diet, physical activity, sleep pattern, and environment is strongly recommended since the intrauterine phase.

Gait Pattern, Impact to the Skeleton and Postural Balance in Overweight and Obese Children: A Review

The article reviews the biomechanical factors that may cause overweight/obese children to reduce their level of physical activity, while increasing their risk of overuse injuries and exercise-related pain. Recommendations would be to screen those children for any gait or postural impairments before they join any exercise program, and to provide them with specific gait treatments and/or physical exercise programs, in order to decrease their risk for future musculoskeletal injuries and pain.

Relationship between knee alignment in asymptomatic subjects and flexibility of the main muscles that are functionally related to the knee

Objective To assess the relationship between static frontal knee alignment in asymptomatic subjects and flexibility of the main muscles functionally related to the knee. Methods A descriptive cross-sectional study was performed in 33 healthy adults (19-31 years). The frontal knee angle (valgus/varus angle) was measured by photogrammetry and it was measured in the lateral side. Therefore, high values were assigned for genu varum and low values for genu valgum. Iliopsoas, gluteus maximus and medius, rectus femoris, biceps femoris, vastus of the quadriceps, and gastrocnemius muscles were stretched. Muscles were classified as normal, reflex hypomobile, or structural hypomobile. Results Women had significantly greater valgus than did men (right angle, women: 174.41°/men: 177.41°; left angle, women: 174.20°/men: 178.70°). The right frontal plane knee angle was higher in women with structural hypomobile vastus. The left frontal plane knee angle was higher in women with structural hypomobile iliopsoas. No relationships were found in men. Conclusions A tighter vastus of the quadriceps and tighter iliopsoas are related to greater genu varum in adult women. Stretching the vastus of the quadriceps and iliopsoas when there is a tendency for excess varus in the knee, to prevent overuse injury or early osteoarthritis, might be clinically relevant.

Relationships Between Standing Frontal-Plane Knee Alignment and Dynamic Knee Joint Loading During Walking and Jogging in Youth Who Are Obese

BACKGROUND

Youth who are obese have high risk of poor knee health and cartilage damage. Understanding factors which may affect knee health in youth who are obese is critical for preservation of knee integrity and function.

OBJECTIVE

This study compared standing frontal-plane knee alignment and knee loading patterns between youth who are obese and those of healthy weight and determine the association between knee alignment and knee loading patterns during walking and jogging.

DESIGN

This study used a cross-sectional matched pair design.

METHODS

Twenty youth who were obese and 20 youth who were healthy-weight (ages 11-18 years) were recruited. Three-dimensional motion analysis quantified standing frontal-plane knee alignment as well as frontal- and sagittal-plane knee moments during walking and jogging. Paired t -tests, multiple analysis of covariance, and Spearman's rank correlation coefficients were used for analysis.

RESULTS

The youth who were obese demonstrated greater knee valgus in standing ( P  = 0.02), lower normalized peak external knee adduction moments during walking ( P  = 0.003), and greater normalized peak external knee extension moments during jogging ( P  = 0.003) compared with the youth who were healthy-weight. Standing knee alignment did not correlate with knee moments in the youth who were obese.

LIMITATIONS

Results are limited to small, homogeneous cohorts. The standing alignment methodology is not validated in this population and may limit interpretation of results.

CONCLUSION

Youth who are obese stand in more knee valgus and have altered knee loading patterns during walking and jogging compared with youth who are healthy-weight. Frontal-plane knee alignment does not correlate with frontal-plane knee loading patterns in youth who are obese. A better understanding of other mechanisms related to joint loading in youth who are obese is necessary to maintain long-term joint integrity in this population.

How does lower leg alignment differ between soccer players, other athletes, and non-athletic controls?

PURPOSE

The influence of type and intensity of sports during growth on knee alignment was investigated. The second aim was to ascertain whether the distal femur or proximal tibia contribute most to knee alignment. Also, the influence of field position and leg dominancy on knee alignment in soccer players was audited.

METHODS

Standardized full-leg standing digital radiographs were obtained from 100 males and 100 females on which 8 different alignment parameters were measured. Participants were questioned on their sports activities during different stages of growth. Sports activities were graded according to the Tegner score.

RESULTS

The mean (±SD) hip-knee-ankle angle (HKA) was significantly lower (p < 0.001) in high-activity male athletes (-2.8° ± 2.4°) than in low-activity male athletes (-0.9° ± 1.9°). No differences in HKA were observed between different activity levels in females. Males who practiced soccer between 10-12 years and 15-17 years had, in turn, a lower HKA than athletes practicing other high-activity sports in these age categories (mean difference ≥1.2°, p ≤ 0.046). The most contributing factor for the varus alignment in male soccer players was a lower medial proximal tibial angle (MPTA).

CONCLUSION

High-activity sports participation during youth is associated with varus alignment at the end of growth in males. The most pronounced bowlegs were observed in male soccer players, and this was primarily determined by the proximal tibia. Adjustments in loads applied to the knees during skeletal growth in males might prevent the development of varus alignment and associated pathology, but further studies are required.

LEVEL OF EVIDENCE

Diagnostic study, Level III.

Do early life factors affect the development of knee osteoarthritis in later life: a narrative review

Osteoarthritis (OA) mainly affects older populations; however, it is possible that early life factors contribute to the development of OA in later life. The aim of this review is to describe the association between childhood or early adulthood risk factors and knee pain, structural imaging markers and development of knee OA in later life. A narrative overview of the literature synthesising the findings of literature retrieved from searches of computerised databases and manual searches was conducted. We found that only a few studies have explored the long-term effect of childhood or early adulthood risk factors on the markers of joint health that predispose people to OA or joint symptoms. High body mass index (BMI) and/or overweight status from childhood to adulthood were independently related to knee pain and OA in later life. The findings regarding the association between strenuous physical activity and knee structures in young adults are still conflicting. However, a favourable effect of moderate physical activity and fitness on knee structures is reported. Childhood physical activity and performance measures had independent beneficial effects on knee structures including knee cartilage in children and young adults. Anterior knee pain syndrome in adolescence could lead to the development of patellofemoral knee OA in the late 40s. Furthermore, weak evidence suggests that childhood malalignment, socioeconomic status and physical abuse are associated with OA in later life. The available evidence suggests that early life intervention may prevent OA in later life.