Talar and Subtalar T1ρ Relaxation Times in Limbs with and without Chronic Ankle Instability

Abstract

Objective The primary aim was to determine differences in talocrural and subtalar joint (STJ) articular cartilage composition, using T1ρ magnetic resonance imaging (MRI) relaxation times, between limbs in individuals with unilateral chronic ankle instability (CAI) and compare with an uninjured control. Our secondary purpose was to determine the association between talocrural and STJ composition in limbs with and without CAI. Design T1ρ MRI relaxation times were collected on 15 CAI (11 females, 21.13 ± 1.81 years, body mass index [BMI] = 23.96 ± 2.74 kg/m2) and 15 uninjured control individuals (11 females, 21.07 ± 2.55 years, BMI = 24.59 ± 3.44 kg/m2). Talocrural cartilage was segmented manually to identify the overall talar dome. The SJT cartilage was segmented manually to identify the anterior, medial, and posterior regions of interest consistent with STJ anatomical articulations. For each segmented area, a T1ρ relaxation time mean and variability value was calculated. Greater T1ρ relaxation times were interpreted as decreased proteoglycan content. Results Individuals with CAI demonstrated a higher involved limb talocrural T1ρ mean and variability relative to their contralateral limb ( P < 0.05) and the healthy control limb ( P < 0.05). The CAI-involved limb also had a higher posterior STJ T1ρ mean relative to the healthy control limb ( P < 0.05). In healthy controls ( P < 0.05), but not the CAI-involved or contralateral limbs (p>0.05), talocrural and posterior STJ composition measures were positively associated. Conclusions Individuals with CAI have lower proteoglycan content in both the talocrural and posterior STJ in their involved limbs relative to the contralateral and a healthy control limb. Cartilage composition findings may be consistent with the early development of posttraumatic osteoarthritis.

Gait Biomechanics and Balance Associate with Talar and Subtalar T1ρ Relaxation Times in Those with Chronic Ankle Instability

“…Although the cumulative literature within the lower extremity shows a consistent relationship between lower loading characteristics and greater T1ρ relaxation times, it is unclear why the associations were seen in the subtalar joint but not the talar dome. We believe this is likely due to the fact that (i) talar and subtalar T1ρ relaxation times do not associate in individuals with CAI (13) and (ii) that the normal shank–rearfoot coupling is disrupted in individuals with CAI (31). It is also possible that subtalar T1ρ relaxation times more closely align with loading-related variables because of the important role the subtalar joint plays in shock absorption (32).…”

“…These increased talar accessory motions would occur concurrently with the large COP displacements during static stance (29) and result in shearing forces to the talar but not the subtalar cartilage. These increased talar but not subtalar accessory motions likely also contribute to the lack of talar and subtalar T1ρ relaxation time associations in individuals with CAI (13). It is less clear why association magnitudes are not consistent across postural control outcomes.…”

“…A single investigator (K. S.) manually segmented (7,8) both the talar and subtalar articular cartilage using all MR slices that contained clearly visible cartilage (12,13). The investigator had previously completed a comprehensive segmentation training plan within our laboratory.…”

“…Greater T1ρ relaxation times were interpreted as less proteoglycan content (i.e., greater degeneration) (9,10). These acquisition and analytic techniques have been used at tibiofemoral (7,8), talar (12), and subtalar articulations (13).…”

High-stress distribution in the lateral region of the subtalar joint in the patient with chronic lateral ankle instability

“…Previous studies using magnetic resonance imaging (MRI) have demonstrated cartilage degeneration in talocrural and subtalar joint. Song et al demonstrated that patients with CLAI have lower proteoglycan content in both the talocrural and posterior subtalar joints compared to the contralateral and healthy control limbs using T1ρ MRI [20]. Kim et al compared T2 relaxation values in the subtalar joint cartilage between patients with CLAI and healthy volunteers, and CLAI showed significantly higher T2 relaxation values in the posterior subtalar joint [21].…”