SLR - September 2021 - Callie Morlock

Magnetic Resonance Imaging T2* Mapping of the Talar Dome and Subtalar Joint Cartilage 3 Years After Anterior Talofibular Ligament Repair or Reconstruction in Chronic Lateral Ankle Instability

Reference: Hu Y, Zhang Y, Li Q, Xie Y, Lu R, Tao H, Chen S. Magnetic Resonance Imaging T2* Mapping of the Talar Dome and Subtalar Joint Cartilage 3 Years After Anterior Talofibular Ligament Repair or Reconstruction in Chronic Lateral Ankle Instability. Am J Sports Med. 2021 Mar;49(3):737-746. doi: 10.1177/0363546520982240. Epub 2021 Feb 8. PMID: 33555910.

Level of Evidence: Level III, Cohort Study

Scientific Literature Review

Reviewed By: Callie Morlock, DPM
Residency Program: North Colorado Medical Center – Greeley, CO

Podiatric Relevance: Ankle sprains are common injuries often involving the anterior talofibular ligament. Most ankle sprains can be treated with conservative measures while surgical intervention is reserved for patients who develop chronic lateral ankle instability. Preventing the incidence of osteochondral lesions to the talar dome and ankle osteoarthritis are ideal surgical outcomes. Anatomic lateral ligament reconstruction is proven to be the better surgical treatment of choice compared to nonanatomic techniques in clinical practice, but the nonanatomic approach is still an option. The purpose of this study was to evaluate changes in the cartilage matrix at the talar dome and subtalar joint after anatomic ATFL repair and reconstruction using MRI T2 mapping and comparing the results to an asymptomatic control group. Additionally, the researchers compared cartilage degenerative changes and clinical scores between anatomic ATFL repair and reconstruction.

Methods: This level 3 cohort study evaluated patients who developed chronic lateral ankle instability and underwent arthroscopic anatomic isolated ATFL repair or reconstruction. Of the 31 patients, 19 had an ATFL repair and 20 had an ATFL reconstruction. The control group consisted of 21 healthy volunteers. Patients underwent a 3.0-T MRI at baseline and three-year follow up while the control group only had baseline imaging performed. The primary outcome was T2 relaxation values of the talar dome and posterior subtalar joint while ankle function was evaluated using AOFAS scores.

Results: Patients who underwent ATFL repair showed significant increase in T2 values on the medial and lateral posterior and central talar cartilage from baseline to three-year follow up. Patients who underwent ATFL repair showed significantly higher T2 values at follow up to all regions except the medial and lateral anterior and lateral central talar cartilage compared to the baseline control group. Patients who underwent ATFL reconstruction showed significant increase in T2 values in the lateral central and posterior cartilage from baseline to three-year follow up. Patients who underwent ATFL reconstruction showed significantly higher T2 values in all regions except medial and lateral anterior talar cartilage compared to the baseline control group. Comparing ATFL repair and reconstruction from baseline to follow up, ATFL repairs showed a significant decrease in T2 values of the lateral calcaneal cartilage compared to ATFL reconstruction. There were no significant differences in the AOFAS score between repair and reconstruction interventions however, patients who underwent repair or reconstruction had significant improvements in AOFAS scores at the three-year follow up.

Conclusions: Researchers concluded that neither ATFL anatomic repair nor reconstruction prevented the advancement of talar dome and posterior subtalar joint cartilage degeneration. While surgical intervention showed significant improvements with AOFAS scores at the three-year follow up, chronic lateral ankle instability may not be fully resolved with anatomic ATFL repair and reestablishment of normal ankle kinetics may not be feasible. Weaknesses of this study include the lack of a nonoperative cohort and the control group being evaluated at baseline only. Future studies should include a nonoperative cohort to compare with a surgical intervention group and a healthy control group over a longer follow up period.

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