Differences in Achilles tendon mechanical properties between professional ballet dancers and collegiate athletes utilizing shear wave elastography.

PURPOSE: To report normative stiffness parameters obtained using shear wave elastography in dorsiflexion from the Achilles tendons in asymptomatic professional ballet dancers and compare them with college-level athletes. METHODS: An Institutional Review Board (IRB)-approved study consists of 28 professional ballet dancers and 64 asymptomatic collegiate athletes. The athletes were further subdivided into runner and non-runner disciplines. Shear wave elastography (SWE) measurements were made in maximum ankle dorsiflexion position. RESULTS AND DISCUSSION: Forty-eight (52%) males and 44 (48%) females were examined with an overall mean age of 22.2 (± 3.8 years). There were no significant SWE differences between dominant and non-dominant legs in both groups and comparing spin vs. non-spin leg of ballet dancers (p > 0.05). Ballet dancers had significantly higher short-axis velocity values than runners and non-runners (2.34 m/s increase and 2.79 m/s increase, respectively, p < 0.001). Long-axis velocity was significantly higher in ballet dancers compared to non-runners (by 0.80 m/s, p < 0.001), but was not different between ballet dancers and runners (p > 0.05). Short-axis modulus was significantly higher in dancers compared to runners and non-runners (by 135.2 kPa and 159.2 kPa, respectively, p < 0.001). Long-axis modulus (LAM) was not significantly different in ballet dancers when compared to runners. CONCLUSION: Asymptomatic professional ballet dancers exhibit greater short-axis tendon stiffness compared to athletes and greater long-axis tendon stiffness compared to non-runners but similar to runners. The functional benefit from elevated short-axis stiffness in dancers is not clear but may be related to greater axial loading and adaptations of the tendon matrix.

Osteochondroses.

The osteochondroses are a group of disorders that affect the epiphysis or epiphyseal equivalent segments of the immature skeleton. These disorders are believed to be primarily the result of traumatic or vascular pathology, often in the setting of overuse, and are usually self-limited. Their imaging findings are based on the time of the study within the natural course of the disease process. Early findings may best be demonstrated by magnetic resonance imaging or may be recognized radiographically as sclerosis of the involved segment. Later disease demonstrates bone fragmentation and collapse, followed by healing where bone architecture is restored with variable reconstitution of the normal morphology.

The use of ocular ultrasound to diagnose retinal detachment: a case demonstrating the sonographic findings.

Retinal detachment is an ophthalmologic emergency that requires immediate medical attention as it can potentially lead to permanent vision loss. The gold standard for diagnosing retinal detachment is dilated funduscopic exam. However, when this exam is not feasible such as in an emergency room setting or if visualization of the posterior portion of the eye is not possible due to vitreous hemorrhage or dense cataracts, ocular ultrasound provides a readily available and effective alternative. We present the sonographic appearance of chronic retinal detachment in a 24-year-old female with a longstanding history of poorly controlled type 1 diabetes who could not undergo dilated funduscopic exam due to intra-ocular hemorrhage. While retinal detachment is more likely to be detected by radiologists on computed tomography (CT) or magnetic resonance imaging (MRI), radiologists should be aware of the ultrasound findings as well, especially as it becomes a more frequently utilized method for diagnosing retinal detachment in an emergency room setting.

CT and MR Imaging of the Postoperative Ankle and Foot.

A variety of surgical procedures exist for repair of both traumatic and degenerative osseous and soft-tissue pathologic conditions involving the foot and ankle. It is necessary for the radiologist to be familiar with these surgical procedures, so as to assess structural integrity, evaluate for complicating features, and avoid diagnostic pitfalls. Adequate interpretation of postoperative changes often requires access to surgical documentation to evaluate not only the surgery itself but the expected timeline for resolution of normal postoperative changes versus progressive disease. Appropriate use of surgical language in radiology reports is another important skill set to hone and is instrumental in providing a high-quality report to the referring surgeons. The pathophysiology of a myriad of surgical complaints, beginning from the Achilles tendon and concluding at the plantar plate, are presented, as are their common appearances at computed tomography and magnetic resonance imaging. Commonly encountered entities include Achilles tendon tear, spastic equinus, nonspastic equinus, talar dome osteochondral defect, tarsal tunnel syndrome, plantar fasciitis, pes planovalgus, pes cavovarus, peroneal tendinosis, lateral ligament complex pathology, Morton neuroma, plantar plate tear, and metatarsophalangeal joint instability. Computer-generated three-dimensional models are included with many of the procedures to provide a more global view of the surgical anatomy. Correlation with intraoperative photographs is made when available. When appropriate, discussion of postoperative complications, including entities such as infection and failure of graft integration, is presented, although a comprehensive review of postoperative complications is beyond the scope of this article. Notably absent from the current review are some common foot and ankle procedures including hallux valgus and hammertoe corrections, as these are more often evaluated radiographically than with cross-sectional imaging. ©RSNA, 2016.

Imaging of ankle replacements.

Significant innovations in the field of total ankle replacement surgery have occurred since the early disappointing experiences with first-generation devices. In recent years, total ankle arthroplasties are commonly placed in patients with end-stage ankle osteoarthrosis, supplanting ankle arthrodesis as the procedure of choice at some institutions. Careful clinical and preoperative radiographic evaluation is helpful to plan concomitant ligament release, ligament reconstruction, or osteotomy. Careful attention to radiographic signs of early hardware loosening or subsidence can prompt intervention while bone loss is still minimal, and computed tomography has an adjunct role in the evaluation of periprosthetic lucency and osteolysis.

Osteochondral lesions of the elbow.

Osteochondral lesions of the elbow are injuries that disrupt the cartilage and subjacent bone, and they most commonly involve the capitellum. The staging, prognosis, and treatment of osteochondral lesions in the elbow are based on a combination of radiographic, magnetic resonance imaging, and arthroscopic findings. Radiographic staging includes the radiolucent, separation, and free (advanced) stages. MR imaging features of instability include cysts, osteochondral fracture, T2 hyperintense rim, subchondral plate defects, and fluid-filled osteochondral defects. Finally, arthroscopic grading of osteochondral lesions increases in severity based on findings of softened cartilage, cartilage fissuring, exposed bone, loose but nondisplaced fragments, and eventually displaced fragments resulting in intra-articular bodies. This pictorial review focuses on osteochondral lesions in the capitellum and trochlea including osteochondritis dissecans, Panner disease, and acute trauma.

Imaging of benign soft tissue tumors.

The evaluation of soft tissue tumors should be approached systematically, with careful assessment of the patient's age, clinical presentation, anatomical location of the mass, and MRI characteristics. The imaging evaluation of a suspected soft tissue mass begins with conventional radiography to exclude an underlying osseous lesion and assess for any lesional calcification. MRI is particularly useful in evaluating the signal intensity, enhancement pattern, and extent of soft tissue masses that can expand beyond fascial planes and involve the neurovascular bundle, joint, or bone. Among the common benign soft tissue tumors, a fairly definitive imaging diagnosis can be made in cases of lipoma, elastofibroma dorsi, hemangiomas, myositis ossificans, giant cell tumor of tendon sheath, and peripheral nerve sheath tumors. In the remaining cases, the differential diagnosis can be narrowed by knowing the patient's demographics and any associated syndromes, in conjunction with recognizing specific MRI features. Knowledge of the World Health Organization's tumor designations and the incidence of specific tumors based on patient age and anatomical location are vital tools for the interpreting radiologist.

Recurrent Shoulder Posteroinferior Subluxation Status Post Reverse Remplissage.

Posterior shoulder dislocation is an uncommon injury that typically follows intense contraction of the external rotator muscles, such as from seizure activity, high-velocity trauma, or intense electrical shock. The diagnosis is often missed or delayed, leading to complications such as functional deficits or osteonecrosis of the humeral head. Closed reduction can be utilized following an initial occurrence, however, repeated insult to the glenohumeral joint may lead to posterior instability. A reverse Hill-Sachs lesion, a vertical impacted fracture of the anteromedial aspect of the humeral head, can occur. Surgical treatment options for posterior instability include the modified McLaughlin procedure also known as the reverse remplissage procedure. Unfortunately, the success rates of this procedure are controversial.

Osteopoikilosis Demonstrating Multiple Joint Involvement in an Adult Male: An Incidental Radiographic Finding.

Osteopoikilosis is a rare condition that is characterized by multiple small non-aggressive appearing sclerotic foci in a periarticular distribution. Typically, it does not cause any symptoms and is diagnosed incidentally on imaging studies done for other reasons. We present a case of osteopoikilosis in a 37-year-old male, which was diagnosed incidentally on radiographs.

Filler Migration and Granuloma Formation After Gluteal Augmentation with Free-silicone Injections.

Gluteal augmentation may be performed using a variety of techniques, including implant-based, autologous fat grafting, local flaps, impermanent filler injection, or, as in this case, by way of permanent filler injection with free-silicone. Of these, free-silicone injections carry one of the highest complication rates, specifically regarding migration of the filler material from the native injection site and induction of painful reactive soft tissue changes at the new filler location. A radiologist providing this diagnosis may assist the clinician, who often cannot obtain a history of illicit silicone injection for gluteal augmentation unless the suspicion is raised. Presented here is a case of painful filler migration to the knee with granuloma formation after free-silicone gluteal injection.

Klippel-Feil Syndrome with Sprengel Deformity and Extensive Upper Extremity Deformity: A Case Report and Literature Review.

INTRODUCTION: Klippel-Feil syndrome (KFS) is a congenital anomaly resulting from fusion of cervical vertebral bodies secondary to the dysregulation of signaling pathways during somite development. It is commonly associated with scoliosis and Sprengel deformity. We present a case of KFS with commonly associated abnormalities as well as deformities that have not yet been reported in the literature. CASE PRESENTATION: A 3-year-old girl presented for further evaluation of a left upper extremity deformity following a negative genetic workup. Upon physical exam and radiographic imaging, the patient was diagnosed with KFS and associated abnormalities including cervical scoliosis, Sprengel deformity, and congenital deformity of the left upper extremity. Deformities of the left upper extremity include radioulnar synostosis, a four-rayed hand, and absent thenar musculature. The Sprengel deformity was corrected surgically with a Woodward procedure. DISCUSSION: Congenital musculoskeletal deformities can be differentiated based upon spinal and limb embryology. The presence of extraspinal abnormalities not originating from somite differentiation may suggest a severe form of KFS. Important considerations in the workup of the KFS patient include looking for deformities of the shoulder girdle and upper extremities to identify abnormalities for intervention at a young age.

Tuberculous Arthritis of the Elbow Joint: An Uncommon Location with a Diagnostic Dilemma.

Musculoskeletal tuberculosis accounts for 1%-3% of all cases of tuberculosis (TB) worldwide with elbow involvement being even less common. The most cases of tuberculous arthritis occur in patients born in and emigrated from endemic regions, especially in patients who are co-infected with human immunodeficiency virus (HIV). We present a rare case of tuberculous septic arthritis of the elbow joint in a 78-year-old African-American female from the United States, with no history of travel abroad. Her presenting symptoms included pain, swelling, and decreased range of motion of the right elbow for six months. She underwent incision and debridement of the elbow joint and was started on empiric intravenous antibiotic therapy for suspected pyogenic septic arthritis. Several weeks later, surgical cultures demonstrated acid-fast bacilli, identified as Mycobacterium tuberculosis (M. tuberculosis) and a four-drug anti-tuberculosis regimen was initiated. Based upon culture results, additional imaging evaluation was undertaken. She did not have any symptoms of a pulmonary disease but was found to be positive for Mycobacterium tuberculosis in sputum cultures and bronchoalveolar lavage. We emphasize the importance of considering a tuberculosis infection in the differential diagnosis of monoarticular arthritis, especially in elderly patients with immune deficient states since early recognition and treatment result in good functional outcomes.

Alkaptonuria.

A 50-year-old woman with a chronic polyarthropathy was seen by her orthopedist for long-standing back and shoulder and worsening hip pain. A lateral labral tear and chronic trochanteric bursitis were diagnosed on hip magnetic resonance imaging, which was otherwise unremarkable. Hip arthroscopy was performed revealing an unusual bluish-tinged femoral head articular surface. Computed tomography scans of the spine were also obtained.

Synovial cutaneous fistula complicating a reverse total shoulder arthroplasty.

Reverse total shoulder arthroplasty is becoming a common form of shoulder arthroplasty that is often performed in the setting of rotator cuff pathology. Infection is a rare complication but is more common in reverse total shoulder arthroplasty than in hemiarthroplasty or anatomic total shoulder arthroplasty. We present the case of a 69-year-old patient with a reverse total shoulder arthroplasty who presented with purulent drainage from the skin of his anterior shoulder. Computed tomography arthrogram confirmed the presence of a synovial cutaneous fistula. Synovial cutaneous fistula is a rare variant of periprosthetic infection that, to our knowledge, has not been described previously in the setting of a reverse total shoulder arthroplasty. Computed tomography arthrogram proved to be a reliable method for confirming the diagnosis and was used for operative planning to remove the hardware.

Recurrent radiation-induced osteosarcoma of the sternum in a patient with remote radiation therapy for breast cancer.

BACKGROUND: Recurrent radiation-induced osteosarcoma of the sternum following remote radiation therapy for breast cancer and sternal reconstruction. CASE: A 51-year-old woman presents with recurrent, radiation-induced sternal osteosarcoma 11 years after receiving both radiation therapy for breast cancer and sternal reconstruction. The case details both her work-up and subsequent course, including reconstructive and curative efforts. DISCUSSION: An uncommon side effect of radiation therapy for breast cancer is development of osteosarcoma of the chest wall. Even rarer is recurrence of the osteosarcoma following sternal reconstruction.

Spectrum of imaging findings in hyperextension injuries of the neck.

Nonphysiologic hyperextension and lateral forces acting on the cervical spine and soft-tissue structures of the neck can result in a wide spectrum of injury patterns. Multiple factors (eg, patient age; the underlying morphologic features of the cervical spine; the magnitude, vector, and maximal focus of the force) all influence the observed patterns and the severity of injury. A review of the 5-year trauma database in two trauma centers revealed various injury patterns that were frequently recognized in patients with clinical evidence or historical documentation of a predominant hyperextension mechanism. Injuries included anterior arch avulsion and posterior arch compression fractures of the atlas, odontoid fractures, traumatic spondylolisthesis and teardrop fracture of C2, laminar and articular pillar fractures, and hyperextension dislocation injuries. More severe injuries were observed in patients with underlying predisposing conditions (eg, degenerative spondylosis, ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis). Knowledge of the involved biomechanical factors provides a framework for understanding these injury patterns. Diagnostic imaging, especially computed tomography and magnetic resonance imaging, plays a fundamental role in the assessment of patients with suspected cervical injury. Furthermore, cross-sectional imaging facilitates the recognition of accompanying injuries to the face, the head, and the vascular structures of the neck.

Incidental detection of bilateral elastofibroma dorsi with F-18 FDG PET/CT.

An 83-year-old asymptomatic woman with a history of breast cancer treated with resection, radiation, and chemotherapy was studied with F-18 FDG positron emission tomography/computed tomography (PET/CT) for staging purposes. The whole-body F-18 FDG PET/CT images revealed poorly circumscribed, bilateral soft tissue masses between the inferior tips of the scapulae and chest wall with a moderate degree of F-18 FDG accumulation. The maximum standardized uptake values were 2.8 for both the left and right lesions. A biopsy or further imaging was not recommended because the lesions were asymptomatic, bilateral, and their imaging features were diagnostic for elastofibroma dorsi. Comparison to a CT scan performed 2 years earlier demonstrated stability of the lesions, further supporting our diagnosis. Recognition of this moderately metabolic benign entity in oncologic patients will avoid unnecessary medical, radiologic, or surgical interventions.