Ultrasound of the nerves of the knee region: Technique of examination and normal US appearance

Abstract

KEYWORDSUltrasound; Knee; Peripheral nerves.Abstract The diagnosis of disorders of the peripheral nerves (PN) has traditionally been based on clinical and electrophysiological data since nerve tissue cannot be visualized on standard radiographs. More recently, however, nerve structures have been evaluated with magnetic resonance imaging (MRI) and ultrasound (US). The former modality is expensive and not available in all institutions. There are also some contraindications to its use, and the assessment of long nerves can be time-consuming since different coils must be used. Thanks to recent advances in sonographic software and hardware, US can now be used for in-depth assessment of the PN of the upper and lower limbs.Most knee disorders involve lesions to the cruciate ligaments and/or the menisci, which are difficult to evaluate with US. However, similar symptoms may be caused by compression of one or more nerves in the knee region or intrinsic disorders involving these structures. Because of their superficial positions, the nerves around the knee can be clearly visualized with US. A thorough knowledge of the normal anatomy of this region and a careful scanning technique are essential for a successful diagnostic US examination. In this article, we will review the normal gross and microscopic anatomy of the nerves in the knee region, the US technique used for their examination, and their normal US appearance.Sommario La diagnosi delle malattie dei nervi periferici (NP) è tradizionalmente basata sui dati derivanti dall'esame clinico e dalla valutazione elettromiografica, in quanto i nervi non sono apprezzabili alla radiografia standard. Recentemente la risonanza magnetica nucleare (RMN) e l'ecografia sono state utilizzate nell'identificazione e valutazione dei NP. La RMN è però una metodica costosa, presenta alcune controindicazioni e non è ancora facilmente * Corresponding author. Privat Docent, Université de Geneve, CH, Consultant radiologist, Clinique et Fondation des Grangettes 7, chemin des Grangettes, CH-1204 Geneva, Suisse.E-mail address: stefanobianchi@bluewin.ch (S. Bianchi). disponibile. In più, la valutazione di lunghi tratti di nervo allunga i tempi d'esame, in quanto richiede l'uso di differenti bobine. I recenti miglioramenti nell'hardware e software delle apparecchiature ecografiche hanno portato a un miglioramento delle immagini ecografiche e a una accurata valutazione dei NP. Nonostante le malattie dei menischi e dei legamenti, di difficile valutazione ecografica, siano predominanti, la compressione e le malattie dei nervi del ginocchio possono essere responsabili dei sintomi riferiti dal paziente. I nervi del ginocchio decorrono superficialmente e sono quindi ben valutabili con l'ecografia. Un'ottima conoscenza dell'anatomia e una rigorosa tecnica d'esecuzione dell'esame sono requisiti indispensabili per un corretto esame ecografico. Nella prima parte di questo articolo ricordiamo l'anatomia microscopica dei NP, seguita da una descrizione dell'anatomia ecografica normale. Quindi, dopo aver breveme...

Reliability of side‐to‐side ultrasound cross‐sectional area measurements of lower extremity nerves in healthy subjects

“…The deep group of nerves was evaluated with a 12–7‐MH Z broadband linear‐array transducer. Anatomical landmarks were chosen for each nerve according to previously published information5–10: Sciatic nerve: Three measurements were performed at the level of the piriformis muscle (Fig. 1), mid‐thigh, and before the bifurcation.…”

“…These data are particularly important for diagnosis of subtle abnormalities of the peripheral nerves. Morever, many nerves amenable to evaluation in clinical practice, such as the femoral,5 lateral femoral cutaneous,5–7 obturator,5, 6 sural, and saphenous nerves,8, 9 have received little attention. We believe that it could be useful to expand the currently available limited reliability literature for the lower limb.…”

Ultrasound Imaging of the Deep Peroneal Nerve

“…Within the tunnel, between the fibular neck and the peroneus longus origin, the CPN usually divides into the DPN, the SPN, and a third smaller branch (the anterior recurrent peroneal nerve); the DPN runs anteriorly and more closely to the fibula than the SPN (Figure 1A). 17–20 …”

Pathological Sonographic Values in Peripheral Nerve Entrapments—A Literature Review

“…Most studies used electro diagnostic tests as the gold standard for the diagnostic confirmation of a peripheral neuropathy (after the diagnosis based on a clinical exam). 6,8,9,12,[14][15][16][17][18][19][20][21][22][23][24][25][26][27] Other studies used nuclear magnetic resonance (NMR) as the main diagnostic tool 28 or as a complementary tool, 5 which also occurred with surgical validation of findings. 4…”

“…Traditionally, the diagnosis of a nerve lesion has been performed via clinical history and physical examination, together with electrophysiological studies (EPS), such as nerve conduction tests and electromyography. [5][6][7] According to Kerasnoudis et al, 1 these objective tests are still essential for diagnostic confirmation and classification of severity. Currently, EPS, magnetic resonance and ultrasound are the main modalities for the assessment of the peripheral nerve.…”