LSTR Osteoarthritis and Obesity Chris C-T Chen, PhD Shevaun Doyle, MD Daniel Green, MD Howard Hillstrom, PhD Hollis Potter, MD Peter A. Torzilli, PhD Hospital for Special Surgery New York City, NY

Self-assessed All types

~21 million Clinical OA Self-assessed

Obesity and osteoarthritis in knee, hip and/or hand Grotle et al. BMC Musculoskelet Disord (2008) In a 1994 Norwegian study of 1854 people aged yrs At 10-years follow-up high BMI (> 30) was associated with Knee OA (OR 2.81; 95%CI ) Hand OA (OR 2.59; ) But not Hip OA (OR 1.11; ) What affect does obesity have on osteoarthritis?

3,068 participants, Johnston County Osteoarthritis Project Black and white women and men age 45+ years rural NC Radiographic, sociodemographic, and symptomatic knee Baseline ( ) and first followup ( ) Lifetime risk of symptomatic knee osteoarthritis Murphy et al., A&R (2008) Symptomatic knee OA risk was 44.7% Knee injury had a lifetime risk of 56.8% Risk increased with increasing BMI Risk of 66% among those who were obese

Knee Osteoarthritis, Body Weight and Joint Alignment Felson et al., Arthritis & Rheumatism (2004) Progression of knee OA via Joint Space Narrowing on Radiographs Patient Population Knees OA Progression90/394 Age66.4±9.4 yrs Women 41.0% BMI30.6±4.7 kg/m 2 Median Alignment2.1 o varus Varus/Neutral/Valgus67%/7%/26% For each 2-unit increase in BMI, there was an 8% increase in the risk of progression (odds ratio=1.08, p=0.03) Percent of malaligned knees with OA progression 9.2% 22.3% 48.7%

Childhood Orthopedic Diseases Linked to Obesity Genuvalgum Slipped Capital Femoral Epiphysis (SCFE) Blount’s Disease (tibia vara) Blount’s Disease

Orthopedic Complications of Overweight in Children and Adolescents Taylor, E.D. et al. (2006) Pediatrics Children (93; <12 yrs) and Adolescents (242; yrs) 227 overweight (BMI>95th percentile) age 12.6± non-overweight (5 th- 95th percentile) age 11.8±2.9 Most common joint compliant was knee pain 6.6% overweight vs. 2.3% non-overweight In adolescents (12-18 yrs) % overweight vs. 4.8% non-overweight Taylor, E.D. et al. (2006). Orthopedic complications of overweight in children and adolescents. Pediatrics. 117 (6):

Tibial Growth Plate and Lower Extremity Alignment 159 overweight vs. 91 non-overweight Tibial growth plate – tibial axial alignment Femoral - tibial axial alignment Tibial-Growth Plate Alignment Valgus alignment Overweight > non-overweight Femoral-Tibial Alignment Not different Tibial-Growth Plate Alignment Fem-Tib Alignment

Obesity and Lower Extremity Malalignment Genu valgum “A major unanswered question in the study of growth plate cellular function is the extent to which chondrocytic activity is also modulated by the biomechanical environment of the growth plate” Cornelia E. Farnum (Cells Tissues Organs 2000)

Surgical Options for Correcting Malalignment Stapling is a successful way to surgically correct valgus and varus deformities caused by unequal growth rates across a given physis. Treatment of Genuvalgum

Obesity, OA and Children Only 19 papers found from Effects of childhood obesity on three-dimensional knee joint biomechanics during walking Gushue, Houck and Lerner, A. L., J Pediatr Orthop (2005) During early stance overweight children had Lower peak knee flexion angle Higher peak internal knee abduction moment Overweight children may develop a gait adaptation leading to increased joint loads and high contact stress Childhood obesity may impart a greater risk for the development of osteoarthritis due to repetitive high stress

Multiscale Modeling Changes in joint mechanics may alter the normal metabolic balance Andriacchi (2004) Annals of Biomedical Engineering Higher Stress Shift in Location Changes in joint mechanics may predispose the joint to develop osteoarthritis

Co-PIs: Howard Hillstrom, PhDHSS Christopher Chen, PhDHSS Alejandro Diaz, MDWeill-Cornell Mary J. Ward, PhDWeill-Cornell Maura D. Frank, MDWeill-Cornell Daniel Green, MDHSS Co-PIs:Peter Torzilli, PhDHSS Mary Goldring, PhDHSS Sherry Backus, PT, DPTHSS Sarah Shultz, PhDTemple Lower Extremity Alignment, Gait, and Joint Pathophysiology in Overweight and Normal Weight Children

 Motion analysis of gait and joint mechanics  Systemetic biomarkers for OA and bone pathophysiology Study the role of joint malalignment and BMI in overweight and normal weight children in the development of osteoarthritis

Obesity, OA and Children Wish List Biomechanical Joint alignment Joint kinematics (motion) Joint dynamics (contact stresses Imaging (hard and soft tissues) Radiographs MR Imaging Biological (hard and soft tissues) Genetic Systemic Biomarkers

Future Collaborators Marjolein van der Meulen, PhD Cornell Engineering School Cornella Farnum, DVM, PhD Cornell Veterinary College Thomas Andriacchi, PhD Stanford University Engineering School