Sonography of the Pronator Teres: Normal and Pathologic Appearances

Lacertus syndrome: recent advances

Lacertus syndrome consists in proximal median nerve entrapment with median nerve compression at the lacertus fibrosus, causing hand weakness and fatigue, forearm pain and occasional numbness. Recent advances emphasized the importance of clinical examination, due to limitations in electromyographic diagnosis and delayed diagnosis. The Hagert clinical triad, lacertus notch sign, lacertus antagonist test and taping help accurate diagnosis. Non-operative treatment should be tried; and surgical techniques, whether open or ultrasound-guided under WALANT (wide-awake, local anesthesia, no tourniquet) show promising outcomes. Improved awareness, accurate diagnosis and innovative treatments enhance patient care for this challenging condition.

Ultrasound-guided median nerve hydrodissection of pronator teres syndrome: a case report and a literature review

Aim of the study

To describe the sonographic appearance of pronator teres syndrome and the role of ultrasound-guided hydrodissection for its management.

Case description

Pronator teres syndrome is a well-known compressive neuropathy of the median nerve between the two heads of pronator teres. However, the clinical presentation of this syndrome can be indolent with vague pain at the proximal volar forearm leading to a delay in diagnosis. We describe our experience in the management of pronator teres syndrome in a healthy young badminton player with ultrasound-guided median nerve hydrodissection. We highlight the clinical presentation, the role of dynamic Ultrasound scan (USS) in the diagnosis and effective treatment of pronator teres syndrome.

Conclusions

In conclusion, managing PTS can be challenging, and this case highlights the importance of ultrasound-guided hydrodissection, when conservative measures have failed to improve the symptoms. Further studies are required to assess and compare the long-term outcomes of these interventions.

Ultrasound exploration of the elbow: A user-friendly approach

Ultrasound is a strong diagnostic and therapeutic tool for the elbow joint. Existing guidelines and protocols list relevant structures to be scanned but lack some logical connection and intermediate exploration manoeuvres to link each step, which we consider crucial from an operator's perspective that aims to be efficient in regular clinical practice. We present thirteen steps that are described in detail and accompanied by forty-seven ultrasound images, logically linked in what we believe is the best balance between detail and a real-world applicable protocol to perform an ultrasound of the elbow joint.

Ultrasonographic evaluation of the median nerve: normal and variant anatomy and appearance

The median nerve is a mixed sensory and motor nerve that innervates part of the flexor muscles in the anterior compartment of the forearm and muscles in the lateral part of the hand; palmar cutaneous and digital cutaneous nerves branch from the median nerve, which provides sensory innervation to the skin on the radial side of the palm. Also, the median nerve is an object of interest because neuropathy of the median nerve at the level of the carpal tunnel is the most common entrapment neuropathy which increases dramatically in patients with diabetes. Neuromuscular ultrasound provides extensive diagnostic information and has proved itself as a useful complementary test to electrodiagnostic examinations in cases involving median nerve neuropathy. It often happens that the cause of nerve entrapment and neuropathy are variants of several anatomical structures along the course of the median nerve. It is important to be aware and report such anatomical variations of the median nerve in order to avoid damaging the nerve during surgical treatment. Despite the frequently documented abnormalities in the pathway of the brachial plexus and the median nerve, the anatomical variations are unusual to see and are rarely reported. Moreover, there are variations that do not fit under any of the classifications described in the literature.

Review Article "Spotlight on Ultrasonography in the Diagnosis of Peripheral Nerve Disease: The Evidence to Date"

Neuromuscular ultrasound is rapidly becoming incorporated into clinical practice as a standard tool in the assessment of peripheral nerve diseases. Ultrasound complements clinical phenotyping and electrodiagnostic evaluation, providing critical structural anatomical information to enhance diagnosis and identify structural pathology. This review article examines the evidence supporting neuromuscular ultrasound in the diagnosis of compressive mononeuropathies, traumatic nerve injury, generalised peripheral neuropathy and motor neuron disease. Extending the sonographic evaluation of nerves beyond simple morphological measurements has the potential to improve diagnostics in peripheral neuropathy, as well as advancing the understanding of pathological mechanisms, which in turn will promote precise therapies and improve therapeutic outcomes.

Prediction Model for Choosing Needle Length to Minimize Risk of Median Nerve Puncture With Dry Needling of the Pronator Teres

OBJECTIVE

The aim of this study was to relate forearm anthropometric measures to ultrasound pronator teres depth to determine the necessary needle length to prevent median nerve (MN) injury during pronator teres dry needling.

METHODS

We conducted a study employing a diagnostic accuracy prediction model (NCT03308279) at a Spanish university center. The study recruited 65 participants to predict the depth of the MN (measured with ultrasound) in the pronator teres using a decision tree algorithm to reduce the risk of MN puncture using 2 needle lengths (13 mm or 25 mm). The decision tree was developed by automatically selecting a cutoff for body mass index, forearm length and circumference, and pronator teres thickness.

RESULTS

For forearm circumferences ≤27.5 cm, the predictive value for the 13-mm needle was 92%. For forearm circumferences >27.5 cm and forearm lengths ≤26.75 cm, the predictive value for the 25-mm needle was 100%.

CONCLUSION

Based upon the findings of this study, we suggest that needle length should be selected according to forearm anthropometric measures to prevent MN injury during pronator teres dry needling.