Intra-articular Lesions in Chronic Lateral Ankle Instability: Comparison of Arthroscopy with Magnetic Resonance Imaging Findings

Abstract

BackgroundChronic lateral ankle instability often accompanies intra-articular lesions, and arthroscopy is often useful in diagnosis and treatment of intra-articular lesions.MethodsPreoperative magnetic resonance imaging (MRI) examinations and arthroscopic findings were reviewed retrospectively and compared in 65 patients who underwent surgery for chronic lateral ankle instability from January 2006 to January 2010. MR images obtained were assessed by two radiologists, and the inter- and intra-observer reliability was calculated. American Orthopedic Foot and Ankle Society (AOFAS) and visual analogue scale (VAS) scores were evaluated.ResultsAbnormalities of the anterior talofibular ligament (ATFL) were found in all 65 (100%) cases. In arthroscopy examinations, 33 (51%) cases had talar cartilage lesions, and 3 (5%) cases had 'tram-track' cartilage lesion. Additionally, 39 (60%) cases of synovitis, 9 (14%) cases of anterior impingement syndrome caused by osteophyte, 14 (22%) cases of impingement syndrome caused by fibrotic band and tissue were found. Sensitivity of MRI examination for each abnormality was: ATFL, 60%; osteochondral lesion of talus (OLT), 46%; syndesmosis injury, 21%; synovitis, 21%; anterior impingement syndrome caused by osteophyte, 22%. Paired intra-observer reliability was measured by a kappa statistic of 0.787 (95% confidence interval [CI], 0.641 to 0.864) for ATFL injury, 0.818 (95% CI, 0.743 to 0.908) for OLT, 0.713 (95% CI, 0.605 to 0.821) for synovitis, and 0.739 (95% CI, 0.642 to 0.817) for impingement. Paired inter-observer reliability was measured by a kappa statistic of 0.381 (95% CI, 0.241 to 0.463) for ATFL injury, 0.613 (95% CI, 0.541 to 0.721) for OLT, 0.324 (95% CI, 0.217 to 0.441) for synovitis, and 0.394 (95% CI, 0.249 to 0.471) for impingement. Mean AOFAS score increased from 64.5 to 87.92 (p < 0.001) when there was no intra-articular lesion, from 61.07 to 89.04 (p < 0.001) in patients who had one intra-articular lesion, and from 61.12 to 87.6 (p < 0.001) in patients who had more than two intra-articular lesions.ConclusionsAlthough intra-articular lesion in patients with chronic lateral ankle instability is usually diagnosed with MRI, its sensitivity and inter-observer reliability are low. Therefore, arthroscopic examination is strongly recommended because it improved patients' residual symptoms and significantly increased patient satisfaction.

Structural abnormalities and persistent complaints after an ankle sprain are not associated: an observational case control study in primary care

“…17,18 Other studies found intra-articular lesions on arthroscopy in 90-97% of the patients seen in secondary care. 19,20 The percentages of abnormalities found in these latter studies are much higher compared with those of the present study. Although this difference could be attributed to the techniques applied, it is most likely caused by the different study populations.…”

“…Although this difference could be attributed to the techniques applied, it is most likely caused by the different study populations. 20 In addition to the frequent abnormalities found in the ligaments, structural damage was also frequently seen in the bone and cartilage. Most apparent are the findings in the talocrural and talonavicular joints.…”

3.0 T MR imaging of the ankle: Axial traction for morphological cartilage evaluation, quantitative T2 mapping and cartilage diffusion imaging—A preliminary study

“…In the literature, the accuracy in the detection of cartilage lesions of the knee has been reported to be as high as 87% at 1.5 T and 90% at 3.0 T [21]. For MR imaging of the ankle, sensitivity in detection of cartilage lesions varied between 50% at 1.5 T and 75% at 3.0 T [5,6]. A slightly higher sensitivity was found for MR arthrography (MRA) and computed tomography arthrography (CTA) [22].…”

“…In contrast to the knee, articular cartilage at the hip and at the ankle is relatively thin (about 1.2-2.4 mm) [20]. On standard MR imaging of the ankle, usually, there is direct contact between the cartilage of both articulating surfaces, thus these surfaces are commonly difficult to evaluate [5]. In the literature, the accuracy in the detection of cartilage lesions of the knee has been reported to be as high as 87% at 1.5 T and 90% at 3.0 T [21].…”

“…Although cartilage lesions at the ankle are usually assessed by MR imaging, its accuracy and interreader reliability is low [5]. Due to relatively thin cartilage layers surface discrimination and evaluation is challenging [6].…”