Acute clinical evaluation for the diagnosis of lateral ankle ligament injuries is useful: A comparison between the acute and delayed settings

PURPOSE

To determine the diagnostic value of seven injury history variables, nine clinical tests (including the combination thereof) and overall clinical suspicion for complete discontinuity of the lateral ankle ligaments in the acute (0-2 days post-injury) and delayed setting (5-8 days post-injury).

METHODS

All acute ankle injuries in adult athletes (≥18 years) presenting up to 2 days post-injury were assessed for eligibility. Athletes were excluded if imaging studies demonstrated a frank fracture or 3 T MRI could not be acquired within 10 days post-injury. Using standardized history variables and clinical tests, acute clinical evaluation was performed within 2 days post-injury. Delayed clinical evaluation was performed 5-8 days post-injury. Overall, clinical suspicion was recorded after clinical evaluation. MRI was used as the reference standard.

RESULTS

Between February 2018 and February 2020, a total of 117 acute ankle injuries were screened for eligibility, of which 43 were included in this study. Complete discontinuity of lateral ankle ligaments was observed in 23 (53%) acute ankle injuries. In the acute setting, lateral swelling had 100% (95% confidence interval [CI]: 82-100) sensitivity, haematoma had 85% (95% CI: 61-96) specificity and the anterior drawer test had 100% (95% CI: 77-100) specificity. In the delayed setting, sensitivity for the presence of haematoma improved from 43% (95% CI: 24-65) to 91% (95% CI: 70-98; p < 0.01) and the sensitivity of the anterior drawer test improved from 21% (95% CI: 7-46) to 61% (95% CI: 39-80; p = 0.02). Clinical suspicion had a positive likelihood ratio (LR) of 4.35 (95% CI: 0.55-34.17) in the acute setting and a positive LR of 6.09 (95% CI: 1.57-23.60) in the delayed setting.

CONCLUSIONS

In the acute setting, clinical evaluation can exclude complete discontinuity (e.g., absent lateral swelling) and identify athletes with a high probability of complete discontinuity (e.g., positive anterior drawer test) of the lateral ankle ligaments. In the delayed setting, the sensitivity of common clinical findings increases resulting in an improved diagnostic accuracy. In clinical practice, this study underlines the importance of meticulous clinical evaluation in the acute setting.

LEVEL OF EVIDENCE

Level III.

Limited intrarater and interrater reliability of acute ligamentous ankle injuries on 3 T MRI

OBJECTIVES

To determine the diagnostic reliability of the Schneck grading system for acute ligamentous injuries of (1) the three major ligamentous ankle complexes, (2) the individual ankle ligaments and (3) the Sikka classification for syndesmosis injury.

METHODS

All acute ankle injuries in adult athletes (≥18 years), presenting to the outpatient department of a specialised Orthopaedic and Sports Medicine Hospital, within 7 days postinjury were screened for inclusion. Ankle injuries were excluded if imaging demonstrated a frank ankle fracture or if the 3 T MRI study could not be acquired within 10 days postinjury. Two radiologists graded the three major ligamentous complexes (lateral ankle complex, deltoid complex and syndesmosis complex) and their comprising individual ligaments according the four-grade Schneck grading system. Syndesmotic injuries were classified according the four-grade Sikka classification for consequent injury of the individual syndesmosis ligaments and the deltoid complex. Agreement and kappa (K) statistics were calculated to determine intrarater and interrater reliability.

RESULTS

Between September 2016 and September 2018, a total of 92 MR scans were obtained (87 patients). Interrater and intrarater reliability of the Schneck grading system was moderate to substantial for the lateral ankle complex (K=0.47-0.76), fair to almost perfect for the syndesmosis complex (K=0.37-0.89) and fair to moderate for the deltoid complex (K=0.14-0.51). For the individual ligaments, kappa values ranged from moderate to substantial for the anterior talofibular ligament (ATFL) (K=0.55-0.73), fair to substantial for the calcaneofibular ligament (K=0.31-0.62) and fair to almost perfect for the anteroinferior tibiofibular ligament (AITFL) (K=0.36-0.89). Diagnostic reliability of the Sikka classification ranged from moderate to almost perfect (K=0.51-0.95).

CONCLUSIONS

Grading of the three major ligamentous complexes and of the individual ankle ligaments according the Schneck grading system resulted in limited diagnostic reliability. When dichotomised for the presence of complete discontinuity, the interrater reliability of the Schneck grading system improved to substantial and almost perfect for the ATFL and AITFL, respectively. Classification of syndesmosis injury according the Sikka classification resulted in moderate interrater reliability.