Yun Sun Choi

Dynamic Sonography of External Snapping Hip Syndrome

Objective. To evaluate the dynamic sonographic findings of external snapping hip syndrome. Methods. Five patients with 7 cases of painful external snapping hip (3 male and 2 female; age range, 14–32 years; mean, 19 years) were examined with sonography. Two patients had bilateral snapping. Dynamic sonographic examinations of hips were performed with a linear 5‐ to 12‐MHz transducer during hip motion. Results. Dynamic sonographic studies of the affected hip revealed causes of the external snapping hip in all cases. It was elicited by an abnormal jerky movement of the iliotibial band overlying the greater trochanter in 5 of 7 cases and of the gluteus maximus muscle in 2 cases. The iliotibial band over the greater trochanter was hypoechoic in 3 of the 5 cases and thickened in 1 case. Dynamic sonography showed good correlations between the jerky movements of the iliotibial band and the gluteus maximus muscle and the painful snapping reported by the patients. Conclusions. Dynamic sonography was helpful in the diagnosis of external snapping hip syndrome; it showed real‐time images of sudden abnormal displacement of the iliotibial band or the gluteus maximus muscle overlying the greater trochanter as a painful snap during hip motion.

Comparison of MRI and Arthroscopy in Modified MOCART Scoring System After Autologous Chondrocyte Implantation for Osteochondral Lesion of the Talus

Magnetic resonance imaging (MRI) and arthroscopy have frequently been used to evaluate articular cartilage. Many studies have compared the accuracy of MRI to that of arthroscopy. However, there have been no previous comparison studies between MRI and arthroscopy in the evaluation of repaired cartilage after autologous chondrocyte implantation using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system. The purpose of this study was to compare the results between MRI and arthroscopy after autologous chondrocyte implantation of an osteochondral lesion of the talus using a modified MOCART scoring system. Our study investigated 27 consecutive cases in 26 patients who underwent follow-up MRI and second-look arthroscopy 1 year following autologous chondrocyte implantation based on their osteochondral lesion of the talus diagnosis. According to the comparison results of those 5 categories, the agreement between MRI and arthroscopy evaluation results was statistically significant with good reliability in the categories of the degree of defect repair and defect filling, the quality of repaired tissue surface, and synovitis. However, the integration with the border zone and the adhesion category showed poor to moderate reliability. There has been no well-established correlation method between arthroscopy and MRI after autologous chondrocyte implantation of an osteochondral lesion of the talus.

Deltoid Ligament and Tibiofibular Syndesmosis Injury in Chronic Lateral Ankle Instability: Magnetic Resonance Imaging Evaluation at 3T and Comparison with Arthroscopy

Objective To evaluate the prevalence of deltoid ligament and distal tibiofibular syndesmosis injury on 3T magnetic resonance imaging (MRI) in patients with chronic lateral ankle instability (CLAI). Materials and Methods Fifty patients (mean age, 35 years) who had undergone preoperative 3T MRI and surgical treatment for CLAI were enrolled. The prevalence of deltoid ligament and syndesmosis injury were assessed. The complexity of lateral collateral ligament complex (LCLC) injury was correlated with prevalence of deltoid or syndesmosis injuries. The diagnostic accuracy of ankle ligament imaging at 3T MRI was analyzed using arthroscopy as a reference standard. Results On MRI, deltoid ligament injury was identified in 18 (36%) patients as follows: superficial ligament alone, 9 (50%); deep ligament alone 2 (11%); and both ligaments 7 (39%). Syndesmosis abnormality was found in 21 (42%) patients as follows: anterior inferior tibiofibular ligament (AITFL) alone, 19 (90%); and AITFL and interosseous ligament, 2 (10%). There was no correlation between LCLC injury complexity and the prevalence of an accompanying deltoid or syndesmosis injury on both MRI and arthroscopic findings. MRI sensitivity and specificity for detection of deltoid ligament injury were 84% and 93.5%, and those for detection of syndesmosis injury were 91% and 100%, respectively. Conclusion Deltoid ligament or syndesmosis injuries were common in patients undergoing surgery for CLAI, regardless of the LCLC injury complexity. 3T MRI is helpful for the detection of all types of ankle ligament injury. Therefore, careful interpretation of pre-operative MRI is essential.

Comparison of MRI and arthroscopy after autologous chondrocyte implantation in patients with osteochondral lesion of the talus.

No reported postoperative evaluation method is accurately correlated with the clinical outcome of repaired cartilage after autologous chondrocyte implantation. This study investigated the correlation of follow-up magnetic resonance imaging (MRI) evaluation and arthroscopic findings to the clinical outcome of surgically repaired osteochondral lesion of the talus with autologous chondrocyte implantation using the modified magnetic resonance observation of cartilage repair tissue (MOCART) scoring system.The study group comprised 21 consecutive patients with an osteochondral lesion of the talus who underwent autologous chondrocyte implantation. One year postoperatively, a follow-up MRI was obtained and a second-look arthroscopy was performed. Although the arthroscopic findings of the repaired osteochondral lesion of the talus showed better correlation with the clinical outcome when used with the modified MOCART scoring system, the higher correlation occurred only within a statistical error range, thus making the correlation not significantly different from the one determined on MRI. Therefore, a second-look arthroscopy is not necessary to evaluate the repaired talar cartilage after an autologous chondrocyte implantation. Magnetic resonance imaging is a useful method for long-term follow-up of patients with osteochondral lesions of the talus.

Postoperative Evaluation after Anterior Cruciate Ligament Reconstruction: Measurements and Abnormalities on Radiographic and CT Imaging.

Reconstruction of a ruptured anterior cruciate ligament (ACL) is a well-established procedure for repair of ACL injury. Despite improvement of surgical and rehabilitation techniques over the past decades, up to 25% of patients still fail to regain satisfactory function after an ACL reconstruction. With development of CT imaging techniques for reducing metal artifacts, multi-planar reconstruction, and three-dimensional reconstruction, early post-operative imaging is increasingly being used to provide immediate feedback to surgeons regarding tunnel positioning, fixation, and device placement. Early post-operative radiography and CT imaging are easy to perform and serve as the baseline examinations for future reference.

A Rare Case of Epiphyseal Chondromyxoid Fibroma of the Proximal Tibia

Chondromyxoid fibroma is an uncommon benign cartilaginous tumor of the bone. It occurs most frequently in the metaphysis of long tubular bones, and an epiphyseal location is exceedingly rare. We present here an unusual case of a chondromyxoid fibroma that occurred in the epiphysis of the proximal tibia with an open growth plate. MR imaging findings of this tumor, which has, to the best of our knowledge, never been described in an epiphyseal location, makes the present case unique.

Comprehensive Assessment of Ankle Syndesmosis Injury Using 3D Isotropic Turbo Spin-Echo Sequences: Diagnostic Performance Compared With That of Conventional and Oblique 3-T MRI.

OBJECTIVE The objective of this study is to evaluate the diagnostic performance of 3D sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) sequences in the evaluation of ankle syndesmosis injuries, compared with that of conventional orthogonal MRI and oblique proton density-weighted turbo spin-echo (TSE) sequences performed with 3-T MRI. MATERIALS AND METHODS This retrospective study included 98 patients with suspected ankle syndesmosis injuries who underwent both MRI and surgery. Fifty patients (mean [± SD] age, 34.5 ± 15.3 years) had acute injuries, and 48 patients (mean age, 28.5 ± 9.6 years) had chronic injuries. For both groups, the diagnostic performance of each MRI sequence with regard to syndesmosis injuries was evaluated. Arthroscopy findings were used as a reference standard to confirm diagnosis. RESULTS No statistically significant differences in the sensitivity, specificity, accuracy, and AUC values were noted between images of the syndesmosis obtained using proton density-weighted TSE sequences and images of the syndesmosis obtained using 3D SPACE sequences (p > 0.05). Interobserver agreement regarding the diagnosis of both acute and chronic syndesmosis injuries was almost perfect for proton density-weighted TSE images (κ > 0.80) and was substantial for 3D SPACE images (κ > 0.75). Both methods of obtaining images of the syndesmosis had a diagnostic performance superior to that of conventional orthogonal MRI. CONCLUSION The performance of 3D SPACE sequences is comparable to that of 2D proton density-weighted MR images for the diagnosis of acute and chronic syndesmosis injuries.

Total Ankle Arthroplasty: An Imaging Overview

With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice.

Sonoelastography in the Evaluation of Plantar Fasciitis Treatment: 3-Month Follow-Up After Collagen Injection.

Objective The aim of this study was to investigate whether ultrasound elastography can demonstrate the outcome of the treatment in comparison with gray-scale imaging. Methods Sixteen patients (mean age, 46.9 years) with plantar fasciitis were prospectively enrolled after unsuccessful conservative treatment. Individuals graded their heel pain on a 100-mm visual analogue scale (VAS) and underwent gray-scale ultrasonography and sonoelastography. Collagen was injected in the heels. Fascial thickness and hypoechogenicity, perifascial edema, and plantar fascial elasticity were evaluated. Follow-up sonoelastography and VAS grading were done 3 months after the injection. Statistical analyses were performed by the paired t test and the Fisher exact test. A P < 0.05 was considered statistically significant. Results Mean plantar fascial thickness showed insignificant decrease on follow-up (from 4.30 [1.37] to 4.23 [1.15] mm, P = 0.662). Fascial hypoechogenicity and perifascial edema did not change significantly after treatment. The mean strain ratio of the plantar fascia was significantly increased (from 0.71 [0.24] to 1.66 [0.72], P = 0.001). Softening of the plantar fascia decreased significantly after injection (from 12 to 3 ft, P = 0.004). Twelve (75%) of 16 patients showed significant VAS improvement at the follow-up. Conclusions Sonoelastography revealed a hardening of the plantar fascia after collagen injection treatment and could aid in monitoring the improvement of the symptoms of plantar fasciitis, in cases where gray-scale imaging is inconclusive.

A Case of Glomangiomatosis of the Ankle and Foot: Ultrasonographic Appearance Correlated With the Magnetic Resonance Imaging Findings.

Glomangiomatosis, a rare category of glomus tumors, comprises 2% to 3% of glomus tumors in adults. We report a case of glomangiomatosis in a 48-year-old man who underwent multiple excisions of recurrent soft tissue masses in the ankle and foot. Ultrasonography revealed multiple nodular soft tissue tumors and dilated vascular channels with increased blood flow, suggesting the presence of vascular tumors. Here, we discuss the ultrasonography imaging features of glomangiomatosis, which have not been previously reported, correlate them with magnetic resonance imaging findings, and provide a brief review of the literature.