Diagnosis and Management of Deltoid Ligament Insufficiency

A clinical guide to the medial ligaments of the ankle: Anatomy, function, diagnosis of injuries and treatment of instability-a narrative review

BACKGROUND

The aim was to provide an update on anatomy and function of the medial ankle ligaments, diagnosis of their injuries and treatment of medial ankle instability.

METHODS

Literature search on PubMed.

RESULTS

Injuries to the deltoid ligament are not uncommon in relation to malleolar fractures and ankle sprains. Chronic instability may lead to ankle osteoarthritis. However, there is no consensus on diagnostic criteria (clinically, by imaging and by arthroscopy), on indications for non-operative and operative treatment, and on standards for repair and reconstruction of the ligament complex. There is no current evidence to support acute repair of deltoid ligament injury. Reports on the effect of isolated deltoid ligament reconstruction are very sparse.

CONCLUSION

There is a need for a focused effort to establish evidence for all aspects of deltoid ligament injury.

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.

Prediction of anterior tibiotalar ligament injury: measurement of the angle between the deep posterior tibiotalar ligament and talus on MRI

Background

Identification of anterior tibiotalar ligament (aTTL) injury is essential because it influences the surgeon's treatment option and patient prognosis.

Purpose

To assess the diagnostic accuracy of the angle measurement between the talus and posterior tibiotalar ligament (talus-pTTL) on magnetic resonance imaging (MRI) in patients with arthroscopically proven aTTL injuries.

Material and Methods

Ankle MRI scans of 67 patients who underwent arthroscopic examination were retrospectively reviewed. The talus-pTTL angle on axial T2-weighted MRI and the medial clear space (MCS) on mortise ankle radiograph were measured. Inter-observer agreement of the measurements was calculated. Also, sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve (AUC) were the metrics of diagnostic accuracy.

Results

AUC was 0.90 for observer 1 with 78.6% sensitivity, 97.4% specificity, 88% accuracy, and 54.7° cutoff value for the talus-pTTL angle. AUC was 0.87 for observer 2 with 85.7% sensitivity, 84.6% specificity, 85.2% accuracy, and 53.7° cutoff value for the talus-pTTL angle. AUC was 0.86 with 82.1% sensitivity, 79.5% specificity, and 80.8% accuracy for observer 1 and 0.79 with 57.1% sensitivity, 92.3% specificity, and 74.7% accuracy for observer 2 for the MCS. Different MCS values and additional capabilities when complemented with the angle measurement showed an increase in diagnostic performances. Intra-observer reliability of MCS and talus-pTTL angle of the two radiologists was excellent. Inter-observer reliability of the two radiologists was excellent for both the talus-pTTL angle (0.95) and the MCS (0.85).

Conclusion

Measurement of the talus-pTTL angle showed good sensitivity, specificity, and accuracy for the evaluation of aTTL injury with excellent inter-observer reliability.

Radiographic Analysis and Clinical Efficacy of Hindfoot Arthrodesis With Versus Without Cotton Osteotomy in Stage III Adult Acquired Flatfoot Deformity

Forefoot varus develops as a result of longstanding adult-acquired flatfoot deformity (AAFD). This occurs with varying degrees of deformity and flexibility. Residual forefoot varus following hindfoot realignment in AAFD can lead to lateral column loading and a persistent pronatory moment in efforts to reestablish contact between the forefoot and the ground. The Cotton osteotomy may serve as a reasonable adjunct procedure to help avoid complications and poor outcomes associated with residual forefoot varus in patients undergoing hindfoot arthrodesis for stage III AAFD. The aim of this study was to compare the radiographic outcomes in patients undergoing isolated hindfoot arthrodesis to patients undergoing hindfoot arthrodesis with adjunctive cotton osteotomy. We retrospectively reviewed 47 patients matched based upon age, sex, and comorbidities who underwent hindfoot reconstruction for the treatment of stage III AAFD between 2015 and 2019. A retrospective radiographic review was performed on standard weightbearing radiographs including anterior-posterior and lateral views preoperatively, postoperatively at the initiation of full weightbearing, and at final follow-up. Statistical analysis utilizing paired t test to calculate p values where <.05 was statistically significant. At final follow-up, radiographic measurements showed statistically significant differences in CAA, calcaneal inclination, talo-calcaneal, and talar tilt (p value <.05). The Cotton osteotomy group showed a quicker return to presurgical activity level and a decreased incident of tibiotalar valgus. Our study suggests that the Cotton osteotomy can address residual forefoot varus and potentially prevent further progression of ankle valgus in AAFD when used in combination with hindfoot arthrodesis.