Pronator quadratus imaging

Sonographic Findings in Adult Congenital Madelung Deformity: A Case Study

This case study describes six sonographic findings, with correlative imaging, in an adult patient with congenital Madelung deformity. Two are typical of congenital Madelung deformity: a thick volar hyperechoic band extending from the ulnar side of the distal radius toward the lunate-triquetrum area, the so-called Vickers ligament, adjacent to the radiotriquetral ligament, and a cortical defect on the ulnar and volar side of the distal radius. Other findings may be also observed, such as a narrowed distance between the Lister tubercle and the distal radioulnar joint, a dorsal subluxation of the ulnar head, an extensor tendons entrapment and pronator quadratus modifications. Although the diagnosis of congenital Madelung deformity is based usually on clinical examination, this rare malformation may remain undiscovered until adulthood. When sonography is used as the first imaging technique, the sonographic findings of congenital Madelung deformity can facilitate diagnosis and the appropriate radiographs.

Sonography of the Pronator Teres: Normal and Pathologic Appearances

The pronator teres muscle is rarely examined during a routine sonographic examination of the elbow joint. Nevertheless, it can be affected by a variety of conditions, including trauma and tumors, and can be implicated in compression of the median nerve. This pictorial essay first illustrates the anatomy and biomechanics of the pronator teres. Then we present the sonographic technique for examination, normal sonographic appearance, and anatomic variations of the pronator teres and adjacent structures as well as sonography of their main disorders. Normal and pathologic sonographic appearances are correlated with magnetic resonance imaging and radiographic results.

Sonographic Quantification of Pronator Quadratus Activity During Gripping Effort

OBJECTIVES

The aim of this study was to obtain quantitative data related to the activity of each head of the pronator quadratus based on dynamic sonographic parameters during gripping effort and to assess their relationships with grip and pronation strengths.

METHODS

The forearms of 33 healthy volunteers were evaluated at 5 positions of axial rotation (full supination, 45° supination, neutral, 45° pronation, and full pronation). Echogenic intensity ratios and muscle thicknesses of each head of the pronator quadratus were measured from transverse cross-sectional sonograms obtained during maximal grip and release. Grip strengths and maximal isokinetic pronation torques at 90°/s and 360°/s were evaluated as strength parameters and correlated with sonographic measures.

RESULTS

Echogenic intensity ratios of both heads significantly decreased during power grip (P ≤ .002). Changes in echogenic intensity ratios of the superficial head were greater when the forearm was pronated compared to supination (P < .001), whereas changes in echogenic intensity ratios of the deep head were constant at all forearm positions. Muscle thicknesses of the superficial head maximally increased at the neutral position during power grip (P < .001), whereas muscle thicknesses of the deep head did not change. There were significant negative correlations between grip strength and echogenic intensity ratios of both heads at all respective forearm positions (P ≤ .048). Pronation torque was significantly correlated with echogenic intensity ratios of the superficial head at all forearm positions and the deep head at 45° and full pronation positions (P ≤ .034).

CONCLUSIONS

The data revealed that the superficial head of the pronator quadratus more actively contracts when the forearm is in pronation, whereas the deep head constantly contracts at all positions. This study suggests that both heads of the pronator quadratus also play a role in grip strength, but the superficial head contributes more to pronation strength.

Sonographic swelling of pronator quadratus muscle in patients with occult bone injury

Background

The disarranged fat stripe of the pronator quadratus muscle (PQ) on radiographs (the PQ sign) is reported to be predictive of subtle bone fractures. This study aimed to report the results of magnetic resonance imaging (MRI) study in the patients in whom bone injury was not radiographically detected around the wrist joint, and the PQ was sonographically swollen following acute trauma.

Methods

We evaluated sonographically the PQ of 55 patients who showed normal radiographs following acute trauma. The sonographic appearance of the PQ was checked on both longitudinal and transverse images. On the longitudinal image, the probe was positioned along the flexor carpi radialis tendon. For the transverse image, we adopted the image of the same level in which the PQ of the unaffected hand showed maximal thickness. The PQ was considered to be swollen with disproportionate hyperechogenicity and/or thickening compared with the unaffected side at least in one of the two images. Of the 55 patients, 25 patients whose PQ was considered to be swollen underwent MRI study. PQ thickness in millimeters was retrospectively measured on longitudinal and transverse sonographic images.

Results

Twenty-three patients (92.0%) had occult bone injury, and two adult patients (8.0%) showed only wrist joint effusion on MRI. Among these 23, the distal radius was the most frequent location of the occult bone injury (20 patients; 9 [36.0%] with an occult fracture line and 11 [44.0%] with bone bruising). In longitudinal image, the mean value of the PQ thickness of affected hands was 6.2 (3.7–9.6 mm; standard deviation [SD], 1.5) and that of unaffected hands was 4.5 (2.3–6.7 mm; SD, 1.2), respectively. In transverse image, that of dominant and nondominant hands was 7.6 (4.6–13.2 mm; SD, 2.0) and 5.5 (3.6–7.5 mm; SD, 1.1), respectively. The mean difference in PQ thickness between affected and unaffected hands was 1.7 (0.1–5.0 mm; SD, 1.1) in longitudinal image and 2.0 (0.3–6.8 mm; SD, 1.7) in transverse image.

Conclusions

Sonographic swelling of the PQ might be indicative of occult bone injury in patients with normal radiographs following acute trauma.

Sonographic appearance of the pronator quadratus muscle in healthy volunteers

OBJECTIVES

The purpose of this study was to investigate the sonographic appearance of the pronator quadratus muscle in healthy volunteers.

METHODS

We sonographically evaluated 30 healthy volunteers (15 men and 15 women). The maximum thickness of the pronator quadratus in millimeters on the volar side at the cortical level was measured on sagittal and axial sonographic images with the volunteers' hands supinated. On the axial image, we classified each hand according to the sonographic contour of the pronator quadratus.

RESULTS

A significant difference in the maximum pronator quadratus thickness between dominant and nondominant hands was shown on each image (P < .01). A comparison between men and women also showed a significant difference irrespective of image or hand dominance. Approximately 1.5 mm on the sagittal image and 1.4 mm on the axial image seemed to be adequate practical values for detecting pronator quadratus thickening. In terms of the pronator quadratus contour, the convex type appeared in most men in both the dominant and nondominant hands. In women, the convex and concave types appeared often in both the dominant and nondominant hands.

CONCLUSIONS

The difference in pronator quadratus thickness between dominant and nondominant hands might need to be taken into account during sonographic studies. However, in many cases, the difference seems to be slight and considerably less than the calculated cutoff value in this study. These results might be useful for sonographic comparison of bilateral pronator quadratus muscles in the clinical setting.

Ultrasound in sports medicine: relevance of emerging techniques to clinical care of athletes

The applications of ultrasound in managing the clinical care of athletes have been expanding over the past decade. This review provides an analysis of the research that has been published regarding the use of ultrasound in athletes and focuses on how these emerging techniques can impact the clinical management of athletes by sports medicine physicians. Electronic database literature searches were performed using the subject terms 'ultrasound' and 'athletes' from the years 2003 to 2012. The following databases were searched: PubMed, Web of Science, Cochrane Library, CINAHL, and SPORTDiscus™. The search produced 617 articles in total, with a predominance of articles focused on cardiac and musculoskeletal ultrasound. 266 of the studies involved application of ultrasound in evaluating the cardiovascular properties of athletes, and 151 studies involved musculoskeletal ultrasound. Other applications of ultrasound included abdominal, vascular, bone density and volume status. New techniques in echocardiography have made significant contributions to the understanding of the physiological changes that occur in the athlete's heart in response to the haemodynamic stress associated with different types of activity. The likely application of these techniques will be in managing athletes with hypertrophic cardiomyopathy, and the techniques are near ready for application into clinical practice. These techniques are highly specialized, however, and will require referral to dedicated laboratories to influence the clinical management of athletes. Investigation of aortic root pathology and pulmonary vascular haemodynamics are also emerging, but will require additional studies with larger numbers and outcomes analysis to validate their clinical utility. Some of these techniques are relatively simple, and thus hold the potential to enter clinical management in a point-of-care fashion. Musculoskeletal ultrasound has demonstrated a number of diagnostic and therapeutic techniques applicable to pathology of the shoulder, elbow, wrist, hand, hip, knee and ankle. These techniques have been applied mainly to the management of impingement syndromes, tendinopathies and arthritis. Many of these techniques have been validated and have entered clinical practice, while more recently developed techniques (such as dynamic ultrasound and platelet-rich plasma injections) will require further research to verify efficacy. Research in musculoskeletal ultrasound has also been helpful in identifying risk factors for injury and, thus, serving as a focus for developing interventions. Research in abdominal ultrasound has investigated the potential role of ultrasound imaging in assessing splenomegaly in athletes with mononucleosis, in an attempt to inform decisions and policies regarding return to play. Future research will have to demonstrate a reduction in adverse events in order to justify the application of such a technique into policy. The role of ultrasound in assessing groin pain and abdominal pain in ultraendurance athletes has also been investigated, providing promising areas of focus for the development of treatment interventions and physical therapy. Finally, preliminary research has also identified the role of ultrasound in addressing vascular disease, bone density and volume status in athletes. The potential applications of ultrasound in athletes are broad, and continuing research, including larger outcome studies, will be required to establish the clinical utility of these techniques in the care of athletes.