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.

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.

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.

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.

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.

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.

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.

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.

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.

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.