Current Concepts in Treatment of Acute Deltoid Instability

Bone marrow edema at ligament insertion is an accurate MRI sign of deltoid ligament injury

BACKGROUND

Magnetic resonance imaging (MRI) is effective in diagnosing deltoid ligament (DL) injury but its sensitivity in chronic cases is low. Additional diagnostic signs are required to reduce the risk of a false negative diagnosis.

PURPOSE

To evaluate the added diagnostic value of bone marrow edema at the ligament insertion (BMELI) of DL to the MRI assessment of chronic DL injury.

MATERIAL AND METHODS

One hundred patients who consecutively came to our institution between November 2018 and December 2021 and underwent arthroscopic surgery for chronic ankle instability (CAI) were enrolled in the present study. Preoperative MR images were retrospectively reviewed by two orthopedic surgeons to evaluate the sensitivity, specificity and interobserver reliability of three MRI signs in diagnosing chronic DL injury, namely, abnormal ligamentous morphological characteristics (ALMC), BMELI and medial clear space (MCS).

RESULTS

Taking arthroscopy as the reference standard, there were 34 patients with and 66 without DL injury. ALMC had 64.71% (22/34; 46.47-79.70) sensitivity and 83.33% (55/66; 71.71-91.00) specificity, BMELI had 70.59% (24/34; 52.33-84.29) sensitivity and 95.45% (63/66; 86.44-98.82) specificity and MCS had 26.47% (9/34; 13.51-44.65) sensitivity and 92.42% (61/66; 82.50-97.18) specificity. Compared with ALMC, BMELI had similar efficacy in superficial cases (P = 0.06) and greater efficacy in deep cases (P = 0.04). All three signs showed good interobserver agreement (kappa values all above 0.7).

CONCLUSION

BMELI can reliably indicate concomitant injury to the DL in CAI patients. Using BMELI as a sign of chronic DL injury when ALMC is unclear may reduce the risk of a false negative diagnosis.

Maisonneuve Fractures of the Ankle: A Critical Analysis Review

»

Maisonneuve fractures (MFs), originally described as subcapital (high) fibular fractures with additional injury to the anterior and interosseous tibiofibular ligaments, display a variable injury pattern, ranging from stable to highly unstable fractures.

»

The high incidence of associated fractures of the posterior malleolus, the medial malleolus, and the anterolateral distal tibia (the "anterior malleolus") as well as the variable position of the fibula in the fibular notch (FN) warrant preoperative examination via computed tomography (CT).

»

The main goal of treatment is anatomic reduction of the distal fibula into the FN, which requires prior reduction of displaced posterior malleolar fractures, if present, to restore the integrity of the FN.

»

Open reduction of the distal fibula into the FN and fixation with 2 transsyndesmotic screws or fixation with a screw(s) and suture-button implant, under direct vision, on the lateral aspect of the ankle joint and anterior tibiofibular alignment are preferred over closed reduction to avoid sagittal or rotational malpositioning, which is associated with an inferior outcome.

»

Intra- or postoperative 3D CT visualization is essential for assessment of the accuracy of the reduction of the distal fibula into the FN.