Clinical & Translational Musculoskeletal Imaging

Our team found that greater progression of structural degenerative disease of the knee was observed in individuals with sustained synovitis (joint inflammation) compared to those without sustained synovitis, suggesting that sustained synovitis is associated with progressive osteoarthritis. 

We also found that effusion-synovitis progression was slowed by weight loss and decrease in local subcutaneous fat. Hoffa-synovitis characterized by fluid in the infrapatellar fat pad increased at the same time, suggesting a decreasing fat pad rather than active synovitis. Decrease in local subcutaneous fat partially mediated the systemic effect of weight loss on synovitis. 

We investigated the effects of weight loss and weight gain on hip and knee radiographic changes, pain, and joint replacement over 4 years in the Osteoarthritis Initiative Cohort. Our results of this large, longitudinal study (n = 2,752 with 4-year follow-up) suggested that weight loss may protect against, and weight gain may exacerbate, radiographic and symptomatic knee OA, while weight change (at a 5% threshold) does not have significant effects on hip OA.

Read more about these projects: 

Effects of Weight Change on Knee and Hip Radiographic Measurements and Pain Over Four Years: Data From the Osteoarthritis Initiative. Joseph GB, McCulloch CE, Nevitt MC, Lynch J, Lane NE, Link TM. Arthritis Care Res (Hoboken). 2023 Apr;75(4):860-868. doi: 10.1002/acr.24875. Epub 2022 Nov 18. 

Associations between weight change, knee subcutaneous fat and cartilage thickness in overweight and obese individuals: 4-Year data from the osteoarthritis initiative. Joseph GB, Takakusagi M, Arcilla G, Lynch JA, Pedoia V, Majumdar S, Lane NE, Nevitt MC, McCulloch CE, Link TM. Osteoarthritis Cartilage. 2023 Nov;31(11):1515-1523. doi: 10.1016/j.joca.2023.07.011. Epub 2023 Aug  

The effect of interactions between BMI and sustained depressive symptoms on knee osteoarthritis over 4 years: data from the osteoarthritis initiative. Joseph GB, McCulloch CE, Nevitt MC, Lynch J, Lane NE, Pedoia V, Majumdar S, Link TM. BMC Musculoskelet Disord. 2023 Jan 12;24(1):27. doi: 10.1186/s12891-023-06132-3. 

We developed a machine learning-based prediction model for incident radiographic osteoarthritis (OA) of the knee over eight years using MRI-based cartilage biochemical composition and knee joint structure, demographics, and clinical predictors, including muscle strength and symptoms. We found that a 10-predictor model including MRI parameters coupled with demographics, symptoms, muscle, and physical activity scores provided good prediction of incident radiographic OA over eight years. 

The degree of thigh intramuscular fat in individuals without OA is fundamental for distinguishing natural variations in intramuscular fat from pathological changes. In this project, we investigated the degree of thigh intramuscular fat in individuals without radiographic OA or frequent pain and assessed the associations of age, sex, and BMI with the degree of intramuscular fat. Goutallier Grades (GGs) of the quadriceps and hamstring muscles were assessed based on 3 T MR images on a scale from 0 (normal muscle) to 4 (more fat than muscle). The associations between demographic variables and GG outcomes were evaluated using mixed effects models. While individuals without radiographic OA or frequent pain generally had low thigh intramuscular fat, higher BMI and age were associated with greater intramuscular fat, and GGs were greater in women than men. The relationship between BMI and intramuscular fat was sex-dependent. Thus, demographic variables must be considered when evaluating intramuscular fat.

Using a novel 0.55T system we studied patients with metal implants at the spine (spinal fusion with metal hardware) and hip (hip arthroplasties) and found that imaging at 0.55T had superior image quality and showed abnormalities better than imaging at 1.5 or 3T. We also performed a biophantom study using metallic implants (steel and titanium screws) in pig knees which demonstrated substantial reduction of artifact size resulting in superior depiction of anatomical structures at 0.55 T MRI.