| Ankle sprains are a common injury in athletics and military training and can result in a period of disability, lost training time, high medical costs and recurrent instability. Ankle sprains are typically a ligamentous injury, varying in severity, that result in variable outcomes ranging from full recovery without persistent symptoms, to persistent instability and need for surgery. A clinical challenge exists to adequately quantify the severity of ankle ligament damage in the acute setting, during the healing process, and following treatment.;The purposes of this dissertation were threefold; (1) to measure the anterior talofibular length (ATFL) using stress ultrasonography (US) following an acute injury and monitor changes in length over time, (2) to investigate the effect of chronic, recurrent instability or a single ankle sprain on ATFL measurement with stress US, and (3) to establish the inter-observer agreement on ATFL and joint abnormalities resulting from ankle sprain and imaged with 10MHz US in the plane of the ATFL.;Twenty-five participants with acute ankle sprains of varying severity participated in the first study and contributed 27 ankle injuries. Subjects underwent stress US exam at baseline (<13 days from injury), again at 3 weeks from injury and 6 weeks from injury and completed the Foot and Ankle Ability Measure questionnaire at each visit. Significant increases in ATFL length were identified at neutral, during anterior drawer and inversion that persisted over time, despite significant improvements in self-reported function.;Sixty participants were separated into three categories for the second study: individuals with healthy ankles without a history of sprain, ankle sprain copers with a history of 1 ankle sprain without residual symptoms, and individuals with chronic ankle instability (CAI) with complaints of ankle instability and reductions in self-reported function. Each subject underwent a stress US examination where US images were captured in the affected ankle in the same fashion as study 1 with 9 images total captured. The ATFL length was measured and a mean length for that subject, at the specific position was calculated and analyzed. Both CAI and copers demonstrated significantly higher ATFL length while under anterior drawer and inversion stress than did healthy subjects, despite copers demonstrating high levels of self-reported function similar to healthy subjects.;The image sets of 45 subjects separated into 3 groups (n=15) (acute sprains, CAI, healthy) were included in study 3 that investigated morphological criteria of ligament injury, joint injury and fluid abnormalities as a result of ankle sprain. Two examiners independently evaluated 9 images per subject according to specific morphological criteria previously described in the literature. The criteria were dichotomized (present or absent) and subsequently evaluated using kappa statistics and positive agreement. ATFL disruptions, fluid escaping the talocrural joint and the identification of talar articular cartilage abnormalities demonstrated acceptable agreement in acute sprains. Talar abnormalities and malleolar degenerative changes were observed in CAI while soft tissue lesions were variable with unacceptable agreement.;In conclusion, these descriptive laboratory studies revealed that participants with a history of any ankle sprain demonstrate significant ATFL lengthening when joint stress is applied and US is used to image the lateral aspect of the talocrural joint. This abnormal lengthening may slightly decline in the weeks following acute sprain, however, evidence suggests that it may not return to normal and joint abnormalities of ligament, talus and lateral malleolus may contribute to the persistent instability experienced in CAI. Stress US can provide valuable, quantitative information regarding ATFL competency in addition to providing morphological information regarding lesions that are associated with poor ankle outcomes. |
PDF Full Text Request