A problem-based approach in musculoskeletal ultrasonography: central metatarsalgia.

Ultrasonography (US) is a useful diagnostic method that can be easily applied to identify the cause of metatarsalgia. The superficial location of structures in the foot, dynamic capability of US, and the ability to perform direct real-time evaluations of the pain site are also strong advantages of US as a modality for examining the foot. Moreover, knowing the possible pain sources to investigate when a patient has a specific site of pain will enhance the diagnostic quality of US, and will help radiologists to perform US efficiently and effectively. The purpose of this article is to review the common etiologies of metatarsalgia including Morton's neuroma, plantar plate injury, synovitis, tenosynovitis, bursitis, and metatarsal fractures, and to discuss their US features.

Accuracy of Preoperative Ultrasonography for Cubital Tunnel Syndrome: A Comparison with Intraoperative Findings.

BACKGROUND: The aim of this study was to assess the consistency between preoperative ultrasonographic and intraoperative measurements of the ulnar nerve in patients with cubital tunnel syndrome. METHODS: Twenty-six cases who underwent anterior transposition of the ulnar nerve for cubital tunnel syndrome were enrolled prospectively. On preoperative ultrasonography, largest cross-sectional diameters of the ulnar nerve were measured at the level of medial epicondyle (ME) and 3 cm proximal (PME) and distal (DME) to the ME on the transverse scan by a single experienced radiologist. Intraoperative direct measurements of the largest diameter at the same locations were performed by a single surgeon without knowledge of the preoperative values. The consistency between ultrasonographic and intraoperative values including the largest diameter and swelling ratio were assessed. RESULTS: Significant differences between ultrasonographic and intraoperative values of the largest diameter were found at all levels. The mean difference was 1.29 mm for PME, 1.38 mm for ME, and 1.12 mm for DME. The mean ME-PME swelling ratio for ultrasonographic and intraoperative measurements was 1.50 and 1.39, respectively, showing significant difference. The mean ME-DME swelling ratio for ultrasonographic and intraoperative measurements was 1.53 and 1.43, respectively, showing no significant difference. CONCLUSIONS: Ultrasonographically measured largest diameters of the ulnar nerve at any levels were smaller than the real values determined intraoperatively. The ME-DME swelling ratio of the ulnar nerve measured by ultrasonography was consistent with the intraoperative measurement.

Imaging analysis of superficial soft tissue lymphomas.

PURPOSE: To describe imaging findings in superficial soft tissue lymphomas, especially those located in the skin and subcutaneous layer. MATERIALS AND METHODS: This study included 44 pathologically confirmed superficial lymphoma lesions. Imaging analysis included the size, margin, location, morphology, homogeneity and multiplicity. RESULTS: A nodular form was the most common (21/44, 47.7%) morphology, and of them, 18 demonstrated a streaky appearance. Most of the lesions demonstrated ill-defined margins (26/44, 59.1%) and homogeneous patterns (35/44, 79.5%). CONCLUSIONS: The imaging findings of superficial soft tissue lymphomas were non-specific. However, if images show multiple nodular lesions with ill-defined margins, we should consider this diagnosis.

Pudendal Nerve Entrapment Syndrome due to a Ganglion Cyst: A Case Report.

Pudendal nerve entrapment syndrome is an unusual cause of chronic pelvic pain. We experienced a case of pudendal neuralgia associated with a ganglion cyst. A 60-year-old male patient with a tingling sensation and burning pain in the right buttock and perineal area visited our outpatient rehabilitation center. Pelvis magnetic resonance imaging showed the presence of multiple ganglion cysts around the right ischial spine and sacrospinous ligament, and the pudendal nerve and vessel bundle were located between the ischial spine and ganglion cyst at the entrance of Alcock's canal. We aspirated the lesions under ultrasound guidance, and consequently his symptoms subsided during a 6-month follow-up. This is the first report of pudendal neuralgia caused by compression from a ganglion cyst around the sacrospinous ligament.

Ultrasonographic findings of the various diseases presenting as calf pain.

There are various causes of calf pain. The differential diagnoses affecting the lower leg include cystic lesions, trauma-related lesions, infection or inflammation, vascular lesions, neoplasms, and miscellaneous entities. Ultrasound (US) provide detailed anatomical information of the calf structures, and it offers the ability to confirm, other calf abnormalities, particularly when deep vein thrombosis (DVT) is ruled out. The purpose of this article is to review the causes of a painful calf presenting as DVT and incidental findings found as part of the work-up of DVT, and to provide a broad overview of US findings and clinical features of these pathologies.

Ultrasound-Guided Percutaneous Removal of Wooden Foreign Bodies in the Extremities with Hydro-Dissection Technique.

OBJECTIVE: We described the technique of ultrasound (US)-guided percutaneous removal of the foreign bodies (FB) with hydro-dissection in the radiologic department and presented video files of several cases. MATERIALS AND METHODS: Four patients referred to the radiology department for US evaluation and US-guided percutaneous removal of the FBs in the upper and lower extremities between November, 2006 and November, 2013 were included in this study. The procedures started with US evaluation for the exact location and shape of the FB. A 5 mm-sized skin incision was made at the site of the nearest point from the FB where no passing arteries or tendons were present. We adopted a hydrodissection technique to separate the FB from adjacent tissue using a 2% lidocaine solution. Injected anesthetics detached the FBs from surrounding tissue and thereby facilitated removal. After the tip of the mosquito forceps reached the FB, the wooden FBs were removed. RESULTS: The mean time required for the entire procedure was approximately 20 minutes. There were no significant complications during the US-guided removal or long-term complications after the procedure. All 4 FBs were successfully removed from the soft tissue under US guidance. CONCLUSION: Ultrasound-guided percutaneous removal of the FBs with hydro-dissection in the radiology department is a less invasive and safe method over surgical removal in the operating room. Additionally, the use of a guide wire and serial dilator may help minimize soft tissue injury and facilitate the introduction of forceps.

Acute severe valgus instability without elbow dislocation.

BACKGROUND: The purpose of this study was to investigate the pathoanatomy of acute valgus instability without elbow dislocation and to evaluate clinical outcomes after operative treatment. METHODS: Seven patients presented with acute severe valgus instability without elbow dislocation or fracture after a single traumatic episode. Five patients had primary repair of the medial collateral ligament (MCL) and flexor-pronator tendon (FPT) with suture anchor. Two patients with highly unstable elbow had primary repair of both the medial and lateral structures. On the basis of magnetic resonance imaging and intraoperative findings, the injury patterns of the ligament, capsule, tendon, and bone structures were evaluated. Clinical outcomes were assessed with the Mayo Elbow Performance Score and the shortened Disabilities of the Arm, Shoulder, and Hand score. RESULTS: A complete tear of the MCL from its humeral origin and FPT was found in all patients. The anterior capsule was also damaged. A stripping-type complete tear of the lateral collateral ligament complex with significant instability was observed in 2 patients. Bone contusion at the capitellum or radial head was found in 6 patients. The mean Mayo Elbow Performance Score and shortened Disabilities of the Arm, Shoulder, and Hand score at final follow-up were 95.7 and 12.0. All patients returned to previous work levels within 4 months after operation. CONCLUSION: These results indicate that complete tears of both the MCL and FPT occur with severe valgus instability. Primary repair of medial structures with suture anchor in acute severe valgus instability can restore stability.

Ultrasonographic findings of Kimura's disease presenting in the upper extremities.

OBJECTIVE: To describe ultrasound findings of Kimura's disease arising in the upper extremities. MATERIALS AND METHODS: Five patients with Kimura's disease confirmed by surgical resection were retrospectively reviewed by two musculoskeletal radiologists and a pathologist. RESULTS: All six lesions involved the epitrochlear area and appeared as partially (n = 5) or poorly (n = 1) marginated subcutaneous masses with the presence of curvilinear hyperechoic bands intermingled within the hypoechoic components by US. Moderate (n = 4) to severe (n = 2) vascular signals were observed in some proportion of the hyperechoic bands by color Doppler US. The associated findings were the increased echogenicity of surrounding subcutaneous fat (n = 6) and adjacent lymphadenopathy (n = 4). Microscopic examination showed proliferation of lymphoid follicles with prominent germinal centers and intervening fibrosis. CONCLUSIONS: In this study, Kimura's disease arising in the upper extremities showed a partially defined hypoechoic subcutaneous mass with internal hyperechoic bands and moderate-to-severe vascularities, increased echogenicity of the surrounding subcutaneous fat and adjacent lymphadenopathy on US. Thus, when these US features are observed in the typical epitrochlear region of an Asian individual, especially if accompanied by peripheral eosinophilia, Kimura's disease should be considered as a possible diagnosis.

Mini-open suture bridge repair with porcine dermal patch augmentation for massive rotator cuff tear: surgical technique and preliminary results.

BACKGROUND: The aim of this study was to describe the mini-open suture bridge technique with porcine dermal patch augmentation for massive rotator cuff tear and to assess preliminary clinical and radiological results. METHODS: Five patients with massive rotator cuff tear for which it was not possible to restore the anatomical footprint underwent mini-open suture bridge repair using a porcine dermal patch. The patients' average age was 53.4 years (range, 45 to 57 years), and the average duration of follow-up was 20.6 months (range, 14 to 26 months). Patients were evaluated with preoperative and postoperative outcome measures, including a visual analog scale (VAS) for pain, the University of California Los Angeles (UCLA) score, and the American Shoulder and Elbow Surgeons (ASES) score. The structural integrity of repaired rotator cuffs was assessed by magnetic resonance imaging 6 months postoperatively. RESULTS: The average VAS pain score, UCLA score, and ASES score improved from 6.8, 15.4, and 39.4 preoperatively to 0.8, 31.2, and 86.4 postoperatively (p = 0.041, 0.042, and 0.043, respectively). Magnetic resonance images obtained at an average of 8 months after surgery showed that four patients had intact repair integrity with graft incorporation. One patient had a re-tear with partial healing but still had a satisfactory clinical outcome. There was no intraoperative or postoperative complication in any patient. CONCLUSIONS: Mini-open suture bridge repair with porcine dermal patch augmentation can be an option in young patients with high physical demands and massive rotator cuff tears for which it is not possible to restore the anatomical footprint.

Ischiofemoral impingement syndrome.

Ischiofemoral impingement syndrome is known as one of the causes of hip pain due to impingement of ischium and femur, and usually correlated with trauma or operation. We report a rare case of ischiofemoral impingement syndrome that has no history of trauma or surgery. A 48-year-old female patient was referred for 2 months history of the left hip pain, radiating to lower extremity with a hip snapping sensation. She had no history of trauma or surgery at or around the hip joint and femur. The magnetic resonance imaging (MRI) of the lumbar spine showed no abnormality, except diffuse bulging disc without cord compression at the lumbosacral area. Electrophysiologic study was normal, and there were no neurologic abnormalities compatible with the lumbosacral radiculopathy or spinal stenosis. Hip MRI revealed quadratus femoris muscle edema with concurrent narrowing of the ischiofemoral space. The distance of ischiofemoral space and quadratus femoris space were narrow. It was compatible with ischiofemoral impingement syndrome. After treatment with nonsteroidal anti-inflammatory drugs, physical therapy, and exercise program, the patient's pain was relieved and the snapping was improved. To our knowledge, this is the first reported case of a nontraumatic, noniatrogenic ischiofemoral impingement syndrome, and also the first case to be treated by a nonsurgical method in the Republic of Korea.

Computed tomography-guided removal of a misplaced acetabular screw.

Open reduction and internal fixation with multiple screws and plates is the treatment of choice in patients with complex acetabular fractures. Two cases of a misplaced acetabular screw were detected on post-operative imaging, and referred to us for CT-guided removal of the misplaced screw. With the patients in the decubitus position, preliminary images were obtained to determine the puncture site and angle of approach. A k-wire was advanced to the head of the screw, over which we inserted a cannulated screwdriver and removed the screw. At each step all procedures were monitored with CT. The average total procedure time was 30 min. We observed no significant complications during or after the procedure. CT-guided removal of a misplaced acetabular screw seems to be a simple and safe procedure.

MRI of chondromyxoid fibroma.

BACKGROUND: Chondromyxoid fibroma is a rare benign primary bone tumor of cartilage. Despite a characteristic radiographic appearance, chondromyxoid fibroma with atypical radiographic findings may mimic more common tumors. PURPOSE: To describe the MR findings of chondromyxoid fibroma. MATERIAL AND METHODS: MR images of 19 histopathologically confirmed chondromyxoid fibromas were retrospectively analyzed for signal intensity, periosteal reaction, adjacent abnormal bone marrow and soft tissue signal, and patterns of contrast enhancement. RESULTS: All cases of chondromyxoid fibroma showed hypointense to intermediate signal intensity and internal hyperintense foci were observed in seven (37%) cases on T1-weighted images. On T2-weighted images, all lesions were hyperintense: peripheral intermediate signal band with central hyperintense signal in 11 (58%) of 19 lesions, whereas diffusely hyperintense with heterogeneous pattern in eight (42%). Periosteal reaction was observed in 11 (58%) of 19 cases. Adjacent abnormal bone marrow or soft tissue signal was observed in 12 (63%) or 14 (74%) of 19 cases, respectively. On contrast-enhanced T1-weighted images, peripheral nodular enhancement was observed in 69% (11/16) and diffuse contrast enhancement was observed in 31% (5/16) with homogeneous (n = 3) or heterogeneous (n = 2) patterns. Among the cases with peripheral nodular enhancement, the peripheral nodular enhancing portion generally corresponded to the peripheral intermediate signal band on T2-weighted images, although the peripheral enhancement was not as wide as a band of intermediate signal intensity. On the other hand, the central non-enhancing portion generally corresponded to the central hyperintense signal intensity on T2-weighted images. CONCLUSION: The helpful features of chondromyxoid fibroma are the peripheral intermediate signal band and central hyperintense signal on T2-weighted images, generally corresponding to the peripheral nodular enhancement and central non-enhancing portion on contrast-enhanced T1-weighted images, respectively.

Gray-scale and color Doppler sonographic appearances of nonsubungual soft-tissue glomus tumors.

BACKGROUND: To evaluate the sonographic findings of soft-tissue nonsubungual glomus tumors. METHODS: The sonographic appearances of nine histologically proven soft-tissue glomus tumors of nonsubungual location in nine patients (mean age, 49 years; M:F = 7:2) were reviewed retrospectively. Doppler examination and surgical excision were performed in all cases. RESULTS: The mean size of the lesions was 1 cm. The margins of the lesions were relatively well-circumscribed in eight of nine patients (89%) with an ovoid shape in seven of nine patients (78%). The vascularity was moderate to rich in all cases, with an arterial flow pattern but no arteriovenous shunt patterns. The "vascular stalk sign" was noted in six cases (67%). CONCLUSIONS: Nonsubungual glomus tumors are rare soft-tissue tumors with abundant vascularity and arterial flow pattern.

Subungual tumors: clinicopathologic correlation with US and MR imaging findings.

Various types of tumors can affect the subungual space, including benign solid tumors (glomus tumor, subungual exostosis, soft-tissue chondroma, keratoacanthoma, hemangioma, lobular capillary hemangioma), benign cystic lesions (epidermal and mucoid cysts), and malignant tumors (squamous cell carcinoma, malignant melanoma). Imaging plays an important role in the detection and differentiation of subungual tumors because of their small size, nonspecific clinical manifestations, and functional significance. Ultrasonography (US)-in particular, high-resolution US with color Doppler studies-provides useful information regarding tumor size, location, shape, and internal characteristics (cystic, solid, or mixed), but it is limited in the further characterization of tissue. Magnetic resonance (MR) imaging has an important role in categorizing tumors according to their anatomic location, pathologic origin, and signal characteristics. There is some overlap between the US and MR imaging features of subungual tumors; however, certain features can allow accurate diagnosis and expedite management when correlated with clinical and pathologic findings.

Nuchal-type fibroma of the buttock: magnetic resonance imaging findings.

Nuchal-type fibroma, first described in 1988 by Enzinger and Weiss, is a rare fibrous growth occurring predominantly in the interscapular and paraspinous regions. It is typically located in the subcutaneous tissue of the posterior neck but may occur in extranuchal soft tissue sites such as the upper back, shoulder, and facial regions. In this article, we describe the magnetic resonance imaging findings of a nuchal-type fibroma that involved the buttock in a 45-year-old woman, and we review and discuss the literature on the subject.

Preoperative localization of cystic lesions in the knee using ultrasound-guided injection of indigo carmine.

PURPOSE: To evaluate the feasibility and effectiveness of preoperative localization of cystic lesions in the knee using ultrasound-guided indigo carmine injection. METHOD: Twenty-three cysts in the knee in 23 patients (M:F = 15:8, mean age, 42 years) were localized preoperatively by ultrasound-guided indigo carmine injection. These included 12 meniscal cysts, 7 popliteal cysts, and 4 ganglion cysts. To stain the lesions, 0.2-3 mL of indigo carmine was injected into the cyst using a 22-gauge spinal needle. After localization, the patient was immediately transferred to the operating room and surgery was performed. Intraoperative findings and arthroscopic images were reviewed. RESULT: All 23 cysts were stained successfully. Twenty cases were confirmed during arthroscopy and 3 cases were confirmed during excisional surgery. There was no significant bleeding/hematoma or anaphylactic reaction. Four patients felt pain during aspiration before indigo carmine injection. The lesions were stained blue and could be clearly identified by the surgeon and were removed arthroscopically or by open surgery. CONCLUSION: Preoperative localization of cystic lesions in the knee joint region using ultrasound-guided indigo carmine injection is a feasible technique and can be easily and safely be performed.

Extra-articular pigmented villonodular synovitis of the subacromial space.

Pigmented villonodular synovitis (PVNS) is a rare, benign, proliferating disease affecting the synovium of joints, bursae, and tendon sheaths. The knee is the most common site of involvement and accounts for up to 80% of cases. Involvement of the shoulder is extremely rare. Only 1 case of involvement of the subacromial space has been reported worldwide. We report a case of localized extra-articular PVNS of the subacromial space that was satisfactorily treated with open excisional biopsy and subacromial bursectomy after diagnostic glenohumeral arthroscopy. We visualized the glenohumeral joint to rule out articular invasion and intra-articular pathology with an arthroscope, which revealed a highly vascular synovium protruding into the intra-articular area of the rotator interval, with no direct invasion by the extra-articular mass. An open excisional biopsy and subacromial bursectomy was performed. The disease has not recurred during an 18-month follow-up period. The clinical manifestation, treatment, and prognosis of extra-articular PVNS are poorly understood, but if the lesion is left untreated, it can invade the surrounding soft tissue and joint. Therefore, early diagnosis and treatment are important for the satisfactory management of PVNS.

Multimodal treatment using surgery, radiotherapy, and chemotherapy in a patient with a perivascular epithelioid cell tumor of the uterus.

Perivascular epithelioid tumor (PEComa), a recently defined tumor, is a very rare disease affecting various organs, most often the uterus. This tumor displays a variety of histologic and clinical features and at this point is regarded as a tumor with uncertain malignant potential. A 9-year-old girl with abdominal pain and vaginal spotting was diagnosed with PEComa of the uterus with metastasis. She received chemotherapy comprising vincristine, ifosfamide, and doxorubicin, as well as radiotherapy after surgery. After this multimodal treatment, there was no evidence of recurrence or further metastasis. She remains disease-free 1.5 years after her initial diagnosis. PEComa of the uterus displaying malignant characteristics may have a more favorable response to more aggressive therapy.

Sacrococcygeal chordoma: MR imaging in 30 patients.

OBJECTIVE: To evaluate MR imaging of sacrococcygeal chordoma. DESIGN AND PATIENTS: Thirty patients (age range 22-80 years) underwent MR imaging for the diagnosis and preoperative evaluation of sacrococcygeal chordomas. Eight patients had follow-up MR examination after treatment. The MR images were performed with T1- and T2-weighted imaging, and gadolinium (Gd)-enhanced imaging. The MR images were analyzed for the signal intensity, enhancing pattern, tumor size, growth pattern of the soft tissue component, and tumor extension. RESULTS AND CONCLUSIONS: T1-weighted images showed low signal masses with foci of high signal intensity in 73% of cases. Tumors enhanced in a variety of patterns after the administration of Gd. Soft tissue masses extending anteriorly were seen in all cases with posterior extension in 77% of cases. The posterior masses involved the surrounding muscles and extended toward the greater sciatic notch, appearing with pseudopodia (87%). Sacroiliac joints were involved in 23% of cases. Four lesions showed intraspinal extension and involvement of the posterior spinal muscles above the level of bony involvement. In 6 patients recurrent tumors were found at or around the surgical margin of the tumor 6 months to 5 years after resection of the sacral tumor. In two of the patients, nodular metastases to the pelvic bones and femur were found 1-4 years after initial examination. In conclusion, MR imaging is useful in the diagnosis and preoperative assessment of sacrococcygeal chordoma. Characteristic findings included sacral mass with heterogeneously high signal intensity with crisscrossing septa on long-repetition-time imaging, well-encapsulated pseudopodia-like or lobulated appearance, and gluteal muscle infiltration. Follow-up MR imaging is helpful to assess for recurrent or metastatic lesions of chordomas.