High-resolution ultrasound of the paratenon of the Achilles calcaneal tendon: anatomical study and description of the paratendinous injection technique.

PURPOSE: The aim of this study is to determine if ultrasound (US) allows a precise assessment of the paratenon (PT) of the Achilles calcaneal tendon (AT), and to anatomically describe the US-guided paratendinous injection technique. METHODS: This study was initially conducted on eight cadaveric specimens using high-resolution ultrasound (HRUS) to examine the PT appearance, thickness, and its relationships with the AT, plantaris tendon (PLT), Kager's fat pad (KFP), sural nerve (SN), and fascia cruris (FC). US-guided paratendinous injection of China ink was performed in all specimens, followed by anatomical dissection to assess injectate distribution. Then, HRUS study of the PT was carried out bilaterally in twenty asymptomatic volunteers (40 legs). Two musculoskeletal radiologists recorded all data in consensus except PT thickness in volunteers which was recorded independently in order to calculate intra and inter-observer reliability. RESULTS: The PT was consistently identified with HRUS along its entire course in both cadaveric specimens (8/8) and volunteers (40/40). The mean PT thickness was 0.54 mm in cadavers and 0.39 mm in vivo, without any correlation with the AT thickness. Intra- and inter observer reliability were respectively excellent and good for PT thickness. All eight (100%) ex vivo China ink injections were accurate, demonstrating a circumferential distribution of the injectate between the PT and the AT, associated with an anterior spread to the KFP. CONCLUSION: HRUS allows visualization of the PT along its entire length, and assessment of its relationships to adjacent structures. US-guided paratendinous injections can accurately and safely deliver injectates in the paratendinous sheath.

Anatomical study of the medial calcaneal nerve using high-resolution ultrasound.

OBJECTIVES: To determine whether high-resolution ultrasound (US) can identify the course and relations of the medial calcaneal nerve (MCN). METHODS: This investigation was initially undertaken in eight cadaveric specimens and followed by a high-resolution US study in 20 healthy adult volunteers (40 nerves) by two musculoskeletal radiologists in consensus. The location and course of the MCN as well as its relationship to adjacent anatomical structures were evaluated. RESULTS: The MCN was consistently identified by US along its entire course. The mean cross-sectional area of the nerve was 1 mm2 (range 0.5-2). The level at which the MCN branched from the tibial nerve was variable, located a mean of 7 mm (range - 7-60) proximal to the tip of the medial malleolus. At the level of the medial retromalleolar fossa, the MCN was located inside the proximal tarsal tunnel a mean of 8 mm (range 0-16) posterior to the medial malleolus. More distally, the nerve was depicted in the subcutaneous tissue at the surface of the abductor hallucis fascia with a mean direct distance to the fascia of 1.5 mm (range 0.4-2.8). CONCLUSIONS: High-resolution US can identify the MCN at the level of the medial retromalleolar fossa, as well as more distally in the subcutaneous tissue at the surface of the abductor hallucis fascia. In the setting of heel pain, precise sonographic mapping of the MCN course may enable the radiologist to make diagnosis of nerve compression or neuroma, and perform selective US-guided treatments. CLINICAL RELEVANCE STATEMENT: In the setting of heel pain, sonography is an attractive tool for diagnosing compression neuropathy or neuroma of the medial calcaneal nerve, and enables the radiologist to perform selective image-guided treatments such as diagnostic blocks and injections. KEY POINTS: • The MCN is a small cutaneous nerve which rises from the tibial nerve in the medial retromalleolar fossa to the medial side of the heel. • The MCN can be depicted by high-resolution ultrasound along its entire course. • In the setting of heel pain, precise sonographic mapping of the MCN course may enable the radiologist to make diagnosis of neuroma or nerve entrapment, and perform selective ultrasound-guided treatments such as steroid injection or tarsal tunnel release.

Stenosing tenosynovitis of the extensor digitorum tendons of the hand: clinical and sonographic features.

OBJECTIVE: To describe the ultrasound (US) features of 18 patients with extensor digitorum communis stenosing tenosynovitis (EDCST). MATERIALS AND METHODS: A retrospective search in the radiologic information systems of two separate Institutions was performed to identify all patients presenting EDCST between January 2010 and September 2019. A total of 18 patients (ten males and eight females; mean age, 57.4 years) were identified and included. Sonographic examinations were retrospectively reviewed by two senior radiologists to assess morphologic changes and power Doppler activity of the extensor retinaculum (ER) and of the extensor digitorum communis (EDC) tendons and sheath. The presence of dynamic impingement between the EDC and the ER was evaluated using video clip records. RESULTS: At the ultrasound, all patients (18/18; 100%) presented thickening of both the ER and EDC tendons associated with EDC tendon sheath effusion. Power Doppler hyperemia of the ER was inconstant and observed in 11 cases (11/18; 61.1%) as tendon sheath effusion observed in 16 cases (16/18; 88.9%). A cyst located inside the EDC of the index finger was observed in three of these patients (3/18; 17%). Dynamic examination showed impingement of the EDC against the ER during active tendon extension in all patients (18/18; 100%). Four of these patients (4/18; 22%) underwent surgery allowing diagnosis confirmation and release of EDCST, while the remaining fourteen patients (14/18; 78%) were either treated conservatively or using US-guided steroid injection. CONCLUSION: US findings of EDCST include thickening of the ER and EDC tendons, EDC tendon sheath effusion, and in some cases presence of an EDC intratendinous cyst. Impingement of the EDC tendons against the ER is well demonstrated using dynamic US.

Anterolateral knee pain related to thrombosed lateral patellar retinaculum veins: Unusual anterolateral pain of the knee.

We describe the ultrasound (US) features of venous thrombosis involving the lateral patellar retinaculum (LPR) veins presenting as anterolateral knee pain. Four male patients, aged 16 to 35 years, were referred for lateropatellar pain with focal tenderness. In two cases, physical examination also demonstrated soft tissue swelling at the anterolateral aspect of the knee. In all four cases, US showed subcutaneous fat edema surrounding a thrombosis involving the LPR veins. Magnetic resonance imaging performed before US in one patient revealed only nonspecific subcutaneous fat edema and was therefore unable to make the correct diagnosis of LPR venous thrombosis.

Relationship Between Spinal-Pelvic Sagittal Balance and Pelvic-Femoral Injuries in Professional Soccer Players.

BACKGROUND: Pelvic-femoral injuries are a common problem in football (soccer) players. However, the risk factors for these injuries are unclear. Our knowledge of spinal-pelvic sagittal balance has increased considerably over the past few years, notably as a result of new radiographic techniques such the EOS radiographic imaging system. PURPOSE: To investigate the link between spinal-pelvic sagittal balance on EOS imaging and the incidence of pelvic-femoral injuries. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Players in a League 1 professional soccer team were observed for 5 consecutive seasons. All players included in the study underwent EOS radiographic imaging. All acute and microtraumatic injuries to the pelvic-femoral complex were recorded prospectively: hamstrings, psoas, quadriceps, adductors, obturators, and pubic symphysis. We analyzed the relationship between injury incidence and key radiographic parameters involved in pelvic balance. RESULTS: A total of 61 players were included (mean age, 24.5 years; n = 149 injuries; mean pelvic tilt, 9.08° ± 5.6°). A significant link was observed between the incidence of pelvic-femoral injuries and pelvic tilt (P = .02). A significant link was also observed between the incidence of acute pelvic-femoral injuries and pelvic tilt (P = .05). In both cases, a high pelvic tilt was associated with a low incidence of injuries. CONCLUSION: In professional soccer players, a low pelvic tilt was associated with a high incidence of all pelvic-femoral injuries as well as acute pelvic-femoral injuries. These results could lead to new preventive methods for these musculotendinous injuries through physical therapy.

Sonographic appearance of a soft-tissue gossypiboma in the forearm with pathologic correlation.

We describe the sonographic, radiologic, and histopathologic appearances of a soft tissue gossypiboma in the forearm of an 81-year-old woman with a history of a radial fracture treated with an internal fixation surgery.

The lateral patellar retinaculum defect: anatomical study using ultrasound.

OBJECTIVE: The purpose of this study was to evaluate whether ultrasound allows precise assessment of a focal defect at the lateral patellar retinaculum (LPR) and to determine its anatomical significance. MATERIALS AND METHODS: This work was initially undertaken in four cadaveric specimens and followed by high-resolution ultrasound study in 48 healthy adult volunteers (96 knees) by two musculoskeletal radiologists. Dimension and location of the LPR defect and its relations to adjacent anatomical structures were analyzed. RESULTS: A focal defect of the LPR through which vessels penetrated was constantly identified by ultrasound in our population. The mean transverse diameter of the defect was 2.4 mm (range, 1-6 mm). The defect was located a mean of 23.7 mm (range, 18-30 mm) proximal to the lateral tibial plateau and 6.6 mm (range, 4-9 mm) lateral to the patellar tendon. Anatomical dissection demonstrated that the LPR defect is related to perforating vessels that originate from the peripatellar anastomotic ring. CONCLUSIONS: The focal defect of the LPR can be depicted by ultrasonography. Reproducible anatomical landmarks for its detection could be defined. Our data suggest the LPR defect may be considered a normal variant rather than a pathologic change.

Ultrasound Features of the Normal and Pathologic Periosteum.

Thickening and elevation of the periosteum from the underlying bone cortex, defined as a periosteal reaction, can be associated with several bone disorders. Although ultrasound (US) has limited possibilities in assessing bones, it can depict a periosteal reaction earlier than plain radiography, thus indicating underlying bone disorders. This pictorial essay aims to illustrate the normal and pathologic US appearances of the periosteum in both children and adults. Several disorders are discussed, such as pediatric bone trauma, infections and tumors, as well as trauma, overuse, including medial tibial stress syndrome, and finally certain seronegative spondyloarthropathies in adults. Whenever US depicts a periosteal reaction, a correlation with clinical and laboratory data is mandatory to differentiate different bone disorders. Computed tomography or magnetic resonance imaging must be performed when an infection or a tumor is suspected based on both US and the clinical presentation.

Soft Tissue Masses of the Knee Related to a Focal Defect of the Lateral Patellar Retinaculum.

We report on the imaging features of 6 soft tissue masses in the anterolateral aspect of the knee related to a focal defect of the lateral patellar retinaculum. In 4 patients (3 female and 1 male; 6-65 years) presenting with nontender palpable soft tissue masses in the anterolateral aspect of their knees, ultrasonography showed a focal defect of the lateral patellar retinaculum with herniation of the Hoffa fat pad, which was only visible in flexion. A magnetic resonance imaging examination performed in 1 case confirmed the defect in the lateral patellar retinaculum but did not show a mass, as the knee was examined only at 10° of flexion. The 2 remaining patients (one male and 1 female; 62 and 55 years) presented with soft tissue masses in their anterolateral knees in both flexion and extension. These masses were related respectively to a lipoma of the Hoffa fat pad and to a ganglion cyst, both herniated through a defect of the lateral patellar retinaculum. Our cases suggest that a focal defect of the lateral patellar retinaculum may be a route for Hoffa fat pad herniation as well as a route for superficial extension of infrapatellar fat lesions such as lipomas and ganglion cysts.

Sonographic Overview of Usual and Unusual Disorders of the Rectus Femoris Tendon Origins.

Rectus femoris muscle proximal injuries are not rare conditions. The proximal rectus femoris tendinous anatomy is complex and may be affected by traumatic, microtraumatic, or nontraumatic disorders. A good knowledge of the proximal rectus femoris anatomy allows a better understanding of injury and disorder patterns. A new sonographic lateral approach was recently described to assess the indirect head of the proximal rectus femoris, hence allowing for a complete sonographic assessment of the proximal rectus femoris tendons. This article will review sonographic features of direct, indirect, and conjoined rectus femoris tendon disorders.

Traumatic avulsion of the superior extensor retinaculum of the ankle as a cause of subperiosteal haematoma of the distal fibula in children. A retrospective study of 7 cases.

OBJECTIVE: To describe a new sonographic feature for a traumatic lesion of the ankle in children. MATERIALS AND METHODS: We present a retrospective review of superior extensor retinaculum (SER) avulsions diagnosed by ultrasound (US) as a cause of subperiosteal haematoma (SPH) and periosteal apposition of the distal fibula in seven children (3 girls and 4 boys, mean age 13.4 years; age range 10-15 years) after an inversion trauma of the ankle. Two children were subsequently examined with magnetic resonance imaging (MRI). RESULTS: At the acute phases (6 children), US showed a hypoechoic collection with periosteal elevation at the fibular insertion of the SER. The fibular cortex and growth plate were unremarkable. The SPH was isolated in three cases and associated with an anterior talofibular ligament sprain in four. In two cases, MRI confirmed the SER periosteal avulsion and the integrity of the distal fibula. At the later phase (one child), US showed a periosteal apposition at the fibular insertion of the SER with hypoechoic thickening of the SER and power Doppler hyperaemia. CONCLUSION: This is the first sonographic description of SER avulsion as cause of SPH of the distal fibula in children. SPH in children should not be considered as pathognomonic of a Salter-Harris type 1 lesion of the distal fibula. Later, it may be responsible for persistent ankle pain. Therefore, SER may be systematically explored in children during US examination of the ankle after trauma.

The accessory coracobrachialis muscle: ultrasound and MR features.

OBJECTIVE: To present the prevalence, clinical relevance, and ultrasound (US) and magnetic resonance imaging (MRI) appearances of the accessory coracobrachialis (ACB) muscle. MATERIALS AND METHODS: We present an US prospective study of the ACB muscle over a 2-year period. Five of the eight patients with suspected ACB on US were subsequently examined by MRI. RESULTS: An ACB muscle was demonstrated by US in eight patients (eight shoulders), including seven females, one male, with mean age 39 years, over 770 (664 patients) consecutive shoulder US examinations referred to our institution yielding a prevalence of 1.04%. In dynamic US assessment, one case of subcoracoid impingement secondary to a bulky ACB was diagnosed. No thoracic outlet syndrome was encountered in the remaining cases. MRI confirmed the presence of the accessory muscle in five cases. CONCLUSIONS: ACB muscle is a rarely reported yet not uncommon anatomic variation of the shoulder musculature encountered only in eight of 664 patients referred for shoulder US study. Its US and MRI appearance is described. One of our patients presented with subcoracoid impingement related to the presence of an ACB.

Idiopathic scoliosis in children and adolescents: assessment with a biplanar X-ray device.

UNLABELLED: Idiopathic scoliosis is one of the most common conditions encountered in paediatric practice. It is a three-dimensional (3D) spinal deformity. Conventional radiography is still the modality of choice for evaluation of children and adolescents with idiopathic scoliosis, but it requires repeat radiographs until skeletal maturity is reached and does not provide information about spinal deformity in all three planes. A biplanar X-ray device is a new technique that enables standing frontal and lateral radiographs of the spine to be obtained at lowered radiation doses. With its specific software, this novel vertical biplanar X-ray unit provides 3D images of the spine and offers the opportunity of visualising the spinal deformity in all three planes. This pictorial review presents our experience with this new imaging system in children and adolescents with idiopathic scoliosis. KEY POINTS: • The biplanar X-ray device produces two orthogonal spine X-ray images in a standing position. • The biplanar X-ray device can assess idiopathic scoliosis with a lower radiation dose. • The biplanar X-ray device provides 3D images of the spine.

Radiographic features of osteogenesis imperfecta.

BACKGROUND: Osteogenesis imperfecta (OI), commonly called "brittle bone disease", is a genetic disorder characterised by increased bone fragility and decreased bone density due to quantitative and/or qualitative abnormalities of type I collagen. Different types of OI exist, from mild to severe; they may lead to death, multiple bone fractures, skeletal deformity and short stature. METHODS: Severe cases are usually diagnosed before birth and may incite the parents to choose therapeutic abortion, whereas milder cases are much more difficult to diagnose and may be sometimes confused with non-accidental injury (NAI) ("child abuse") in young children. Whatever the degree of severity, conventional radiography still remains the mainstay in diagnosing OI. RESULTS: The prognosis of this disorder has changed in the last few years thanks to biphosphonate therapy. CONCLUSION: The aim of this pictorial review is to illustrate the radiographic manifestations of OI, including in children receiving biphosphonates, and to outline specific patterns that help differentiate OI from NAI when necessary. KEY POINTS: • The main radiographic features of OI are osteopenia, bone fractures and bone deformities. • Some radiographic features depend on the type of OI or may be encountered with biphosphonates.

Entrapment neuropathies of the shoulder.

Entrapment neuropathies are a rare but presumably underdiagnosed cause of shoulder pain and painful instability. Radiologists must be aware of the clinical presentations and imaging features of these neuropathies because they may be the first to suggest these diagnoses. In this article, instead of a classical nerve-by-nerve approach, entrapment neuropathies are deciphered according to the clinical situation: which anatomic structures may be involved, how to explore them, which imaging abnormalities can be expected, how to manage differential diagnoses, and which therapeutic options can be considered.

Anatomical study of the pisotriquetral joint ligaments using ultrasonography.

OBJECTIVE: The aim of this study was to demonstrate that ultrasonography may allow a precise assessment of the primary stabilizers of pisotriquetral joint (pisohamate, pisometacarpal, and ulnar pisotriquetral ligaments). METHODS AND MATERIALS: This study was initially undertaken in eight cadavers. Metal markers were placed in the ligaments using ultrasonographic guidance, followed by the dissection of the wrists. High-resolution ultrasonography was then performed in 15 volunteers (30 wrists) for the analysis of the presence, appearance, and thickness of the ligaments. RESULTS: At dissection, the metal markers were located in the ligaments or immediately adjacent to them, confirming that they were correctly depicted using ultrasonography. The three ligaments could also be identified in each volunteer. The optimal positioning of the probe and the dynamic maneuvers of the wrist allowing the strain of these ligaments could be defined. No significant changes in the appearance and thickness of the ligaments could be observed. CONCLUSIONS: The three ligaments stabilizing the pisotriquetral joint can be identified using ultrasonography. Further studies are now required to know whether this knowledge may be useful in the assessment of pain involving the ulnar part of the wrist.

Retinacular disorders of the ankle and foot.

The retinacula of the ankle are distinct structures defined as regions of localized thickening of the crural fascia covering the deep structures of the distal portion of the leg, ankle, and foot. Their role is to maintain the approximation of the tendons to the underlying bone. The retinacula of the ankle and foot contain the extensor retinaculum, the peroneal retinaculum, and the flexor retinaculum. Knowledge of the normal anatomy and imaging appearance of these structures is essential for the depiction of their injuries. Even though they may provide an explanation for chronic and unexplained residual pain after an injury, they are frequently overlooked or misdiagnosed.

Anatomical study of phrenic nerve using ultrasound.

PURPOSE: To demonstrate whether ultrasonography may allow a precise assessment of the course and relations of the phrenic nerve in its cervical portion. METHODS: This study, initially undertaken in five cadavers, was followed by high-resolution ultrasonographic study in 20 volunteers (40 nerves) by two radiologists in consensus. The location, course and relations of the phrenic nerve to the adjacent anatomical structures were analysed. RESULTS: The phrenic nerve could be nicely identified through the majority of its course by high-resolution ultrasonography. Useful anatomic landmarks for the detection of the nerve could be defined; these include the transverse cervical and ascending cervical arteries. Some anatomical variations were observed. CONCLUSION: Knowledge of the nerve's precise location, which may demonstrate individual variations, may have useful clinical applications.

New MRI sequences.

Every year, manufacturers of MRI machines introduce new sequences. Most of them result in improved spatial resolution and signal contrast, occasionally with a decrease in sequence duration or MRI time (as when a single 3D sequence is substituted for three 2D sequences). Some sequences that are specifically designed to obtain structural or functional information about a specific tissue (ultrashort TE, T2 mapping, spectro-MRI) are used only for research purposes. Diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and tractography constitute an original microarchitectural approach based on water molecule diffusion. These methods are nearly ready to be introduced into clinical practice. They are discussed in this article.