Matthew C. Gallo

T1ρ and T2 relaxation times are associated with progression of hip osteoarthritis

OBJECTIVE To evaluate whether baseline T1ρ and T2 relaxation times of hip cartilage are associated with magnetic resonance imaging (MRI) based progression of hip osteoarthritis (OA) at 18 months. METHODS 3T MRI studies of the hip were obtained at baseline and 18-month follow-up for 54 subjects without evidence of severe OA at baseline [Kellgren-Lawrence (KL) score of 0-3]. 2D fast spin-echo sequences were used for semi-quantitative morphological scoring of cartilage lesions and a combined T1ρ/T2 sequence was used to quantitatively assess cartilage composition. Progression of hip OA was defined based on incident or progression of morphological semi-quantitative grade at 18 months. Baseline T1ρ and T2 relaxation times were compared between progressors and non-progressors using one-way analysis of variance and Mann-Whitney U tests and used to predict progression with binary logistic regression after adjusting for age, gender, body mass index, and KL score. Additionally, a novel voxel-based relaxometry technique was used to compare the spatial distribution of baseline T1ρ and T2 between progressors and non-progressors. RESULTS Significantly higher baseline T1ρ and T2 values were observed in hip OA progressors compared to non-progressors, particularly in the posterosuperior and anterior aspects of the femoral cartilage. Logistic regression showed that higher baseline T1ρ or T2 values in the femoral cartilage were significantly associated with progression of femoral cartilage lesions at 18 months. CONCLUSION T1ρ and T2 relaxation parameters are associated with morphological cartilage degeneration at 18 months and may serve as potential imaging biomarkers for progression of cartilage lesions in hip OA.

Longitudinal study using voxel-based relaxometry: Association between cartilage T1ρ and T2 and patient reported outcome changes in hip osteoarthritis

To study the local distribution of hip cartilage T1ρ and T2 relaxation times and their association with changes in patient reported outcome measures (PROMs) using a fully automatic, local, and unbiased method in subjects with and without hip osteoarthritis (OA).

Joint Loading in the Sagittal Plane During Gait Is Associated With Hip Joint Abnormalities in Patients With Femoroacetabular Impingement

Background: Femoroacetabular impingement (FAI) is a morphological abnormality of the hip joint that results in functional impairments during various activities of daily living (ADL) such as walking. Purpose/Hypothesis: The purpose of this study was to determine if lower extremity joint loading differed between patients with FAI and controls and to determine whether these altered biomechanical parameters were associated with intra-articular abnormalities. It was hypothesized that patients with FAI would exhibit altered lower extremity joint loading during walking when compared with healthy controls and that these altered joint loading patterns would be associated with intra-articular abnormalities. Study Design: Controlled laboratory study. Methods: Lower extremity kinetics was assessed during walking at a self-selected speed in 15 presurgical patients with FAI and 34 healthy controls matched for age and body mass index. All participants underwent unilateral hip magnetic resonance imaging (MRI) to assess hip joint abnormalities. Hip joint abnormalities were assessed using a semiquantitative MRI-based scoring system. Self-reported outcomes of pain and function were obtained using the Hip disability and Osteoarthritis Outcome Score (HOOS), and physical performance was measured using the 6-minute walk test (6MWT). Group differences were assessed using an independent t test and analysis of variance. In the patients with FAI, associations of joint kinetics with HOOS subscores and intra-articular abnormalities were assessed using the Pearson (r) and Spearman (ρ) correlation coefficients, respectively. Results: Compared with the control group, the FAI group exhibited a significantly increased severity of acetabular (FAI: 1.87 ± 1.55; control: 0.47 ± 0.79; P < .001) and femoral (FAI: 3.27 ± 2.79; control: 1.21 ± 1.55; P = .002) cartilage abnormalities, increased levels of pain (FAI: 65.0 ± 18.8; control: 98.2 ± 3.4; P = .001), and reduced function (FAI: 67.2 ± 21.5; control: 98.9 ± 3.4; P < .001) but similar walking speeds (FAI: 1.55 ± 0.19 m/s; control: 1.63 ± 0.22 m/s; P = .20) and 6MWT performance (FAI: 628.0 ± 91.2 m; control: 667.2 ± 73.4 m; P = .13). The FAI group demonstrated increased hip flexion moment impulses (FAI: 0.14 ± 0.04 N·m·s/kg; control: 0.11 ± 0.03 N·m·s/kg; P = .03), peak ankle dorsiflexion moments (FAI: 1.64 ± 0.16 N·m/kg; control: 1.46 ± 0.31 N·m/kg; P = .04), and ankle dorsiflexion moment impulses (FAI: 0.39 ± 0.07 N·m·s/kg; control: 0.31 ± 0.07 N·m·s/kg; P = .01) compared with the control group. Within the FAI group, an increased hip flexion moment impulse during walking was significantly correlated with increased pain (r = −0.60, P = .03), decreased ADL (r = −0.57, P = .04), and increased severity of acetabular cartilage abnormalities (ρ = 0.82, P < .01). Conclusion: Patients with FAI exhibited altered hip and ankle joint loading patterns during walking. These data suggest that patients with FAI demonstrate both local and distal joint alterations during walking and that hip joint loading is directly related to hip joint abnormalities. Clinical Relevance: The results of this study suggest that the hip flexion moment impulse may be an important biomechanical parameter to understand FAI, as the hip flexion moment impulse during walking was shown to be directly related to hip joint abnormalities on MRI.

Abnormal Joint Moment Distributions and Functional Performance During Sit-to-Stand in Femoroacetabular Impingement Patients.

Femoroacetabular impingement (FAI) is a morphological abnormality of the hip joint that causes pain when performing a mechanically demanding activity of daily living such as the sit‐to‐stand (STS) task. Previous studies have assessed lower extremity joint mechanics during an STS task in various pathologies, yet the STS task has not been studied in FAI patients.

Quantitative magnetic resonance arthrography in patients with femoroacetabular impingement

Quantitative MRI (QMRI) of the hip with sequences such as T1ρ and T2 mapping has been utilized to detect early changes in cartilage matrix composition. However, QMRI has not been performed in the presence of intra‐articular contrast. Thus the purpose of this study was to evaluate the feasibility and use of QMRI during MR‐arthrography (MRA) in femoracetabular impingement (FAI) patients.

A novel mr‐based method for detection of cartilage delamination in femoroacetabular impingement patients

In this study, quantitative magnetic resonance based measurements were used to evaluate T1ρ and T2 mapping and heterogeneity in femoroacetabular impingement (FAI) patients with acetabular cartilage delamination and to determine the ability of these quantitative MR‐based measurements in detecting delamination. Unilateral hip joint MR‐scans of 36 FAI patients with arthroscopically‐confirmed acetabular cartilage delamination and 36 age, gender, and BMI matched controls were obtained. T1ρ and T2 mapping and heterogeneity of the hip joint articular cartilage were assessed in both groups using voxel‐based relaxometry (VBR). Quantitative MR‐based measurements were compared using statistical parametric mapping (SPM). Receiver operating characteristic (ROC) analysis was used to assess the ability of these quantitative measurements in detecting delamination by calculating the area under the curve (AUC). Pearson partial correlations (r) were used to assess for associations between T1ρ and T2 radial heterogeneity with the alpha angle in FAI patients. T1ρ and T2 global acetabular values were significantly higher in FAI patients with a focal increase within the posterior acetabular cartilage. FAI patients exhibited increased anterior superior acetabular T1ρ and T2 heterogeneity and both of these measures demonstrated a strong ability to detect acetabular cartilage delamination (T1ρ AUC: 0.96, p < 0.001; T2 AUC: 0.93, p < 0.001). FAI patients with a larger alpha angle exhibited increased anterior superior acetabular T1ρ (r = 0.48, p = 0.02) and T2 (r = 0.42, p = 0.03) heterogeneity. T1ρ and T2 heterogeneity within the anterior superior acetabular cartilage was shown to be a sensitive measure in detecting delamination and may prove beneficial to clinicians in determining optimal interventions for FAI patients.

Study of the interactions between proximal femur 3d bone shape, cartilage health, and biomechanics in patients with hip Osteoarthritis

In this study quantitative MRI and gait analysis were used to investigate the relationships between proximal femur 3D bone shape, cartilage morphology, cartilage biochemical composition, and joint biomechanics in subject with hip Osteoarthritis (OA). Eighty subjects underwent unilateral hip MR‐imaging: T1ρ and T2 relaxation times were extracted through voxel based relaxometry and bone shape was assessed with 3D MRI‐based statistical shape modeling. In addition, 3D gait analysis was performed in seventy‐six of the studied subjects. Associations between shape, cartilage lesion presence, severity, and cartilage T1ρ and T2 were analyzed with linear regression and statistical parametric mapping. An ad hoc analysis was performed to investigate biomechanics and shape associations. Our results showed that subjects with a higher neck shaft angle in the coronal plane (higher mode 1, coxa valga), thicker femoral neck and a less spherical femoral head (higher mode 5, pistol grip) exhibited more severe acetabular and femoral cartilage abnormalities, showing different interactions with demographics factors. Subjects with coxa valga also demonstrated a prolongation of T1ρ and T2. Subjects with pistol grip deformity exhibited reduced hip internal rotation angles and subjects with coxa valga exhibited higher peak hip adduction moment and moment impulse. The results of this study establish a clear relationship between 3D proximal femur shape variations and markers of hip joint degeneration—morphological, compositional, well as insight on the possible interactions with demographics and biomechanics, suggesting that 3D MRI‐based bone shape maybe a promising biomarker of early hip joint degeneration.

CHAPTER 23:Challenges for the Early Detection of Degenerative Cartilage Changes Using Magnetic Resonance Imaging In vivo in Humans

In this chapter we review magnetic resonance imaging (MRI) techniques for the assessment of cartilage morphology and cartilage biochemistry in vivo in human subjects. Methods for lesion identification, volume and thickness changes, and biochemical changes associated with cartilage degeneration and injury are discussed. The advances and challenges in MRI in this realm are vast, and a concise summary is presented.