Cubital tunnel syndrome (CuTS) is generally treated successfully by surgery and recurrent cases are rare. This study retrospectively investigated the clinical characteristics of recurrent CuTS caused by ganglion.

We evaluated nine patients who were surgically treated for recurrent CuTS caused by ganglion. Age distribution at recurrence ranged from 43 to 79 years. The initial surgery for CuTS had been performed using various methods. The asymptomatic period from initial surgery to recurrence ranged from 22 to 252 months. Clinical, diagnostic imaging, and operative findings during the second surgery were analyzed. All patients were treated by anterior subcutaneous ulnar nerve transposition with ganglion resection and later examined directly within a mean of 71 months after the second surgery.

The interval from recurrence to consultation was shorter than two months for eight cases. Chief complaints included numbness with or without pain in the ring and little fingers in all patients and resting pain in the medial elbow in five patients. Elbow osteoarthritis was present in all cases. Although four of 10 ganglia were palpable, ultrasonography and magnetic resonance imaging could identify all ganglia preoperatively. The ulnar nerve typically had become entrapped by the ganglion posteriorly and by fascia, scar tissue, and/or muscle anteriorly. Chief complaints and ulnar nerve function were improved in all patients following revision surgery.

The acute onset of numbness with or without intolerable pain in the ring and little fingers after a long-term remission period following initial surgery for CuTS in patients with elbow osteoarthritis appears to be the characteristic clinical profile of recurrent CuTS caused by ganglion. As ganglia are often not palpable, ultrasonography and magnetic resonance imaging are recommended for accurate diagnosis.

Ultrasonography of the ulnar nerve has been recommended as a useful additional test in ulnar neuropathy at the elbow (UNE).

We searched the literature and systemically reviewed all clinical trials in UNE. We also looked for articles about the normal sonoanatomy and specific causes of UNE.

Seven of 14 clinical trials in UNE were suitable for further analysis. Ultrasonographic ulnar nerve size measurement appears to be a test with good diagnostic accuracy. The most frequently reported abnormality was an increased cross-sectional area of the ulnar nerve at the elbow. However, several studies had methodological flaws. In addition, the ultrasonographic techniques and study designs differed among the studies. There were a few other uncontrolled studies about the underlying causes of UNE.

The role of ultrasonography in UNE seems promising but could not be firmly established. More prospective studies are needed, and we make several recommendations for further research.

Epineural ganglia are considered to be a usual cause of peripheral nerve compression. In this report, we present a rare case of ulnar nerve compression by an epineural ganglion in the cubital tunnel. A 28-year-old right-handed female secretary developed progressive pain, numbness, and weakness in her right elbow, forearm, and hand for 6 months. Atrophy of the adductor pollicis and the first dorsal interosseous muscles was apparent. Clinical examination revealed a cystic mass at the posterior side of the elbow. Magnetic resonance imaging identified a ganglion while electrophysiologic studies revealed a severe conduction block of the ulnar nerve at the elbow. During surgery a 2-cm diameter epineural ganglion was identified compressing the ulnar nerve and was excised using microsurgery techniques. Two months postoperatively, the clinical recovery of the patient was very satisfactory, although the postoperative electrophysiologic studies demonstrated a less dramatic improvement.

The progressive refinement of broadband transducers with frequencies higher than 10 MHz and improved near-field resolution has enhanced the potential of sonography to evaluate a variety of nerve entrapment syndromes occurring in the upper limb, such as suprascapular neuropathy in the area of the spinoglenoid-supraspinous notch, the quadrilateral space syndrome (axillary neuropathy), radial neuropathy in the area of the spiral groove, the supinator syndrome (posterior interosseous neuropathy), the cubital tunnel syndrome (ulnar neuropathy), and the Kiloh-Nevin syndrome (anterior interosseous neuropathy). In these settings, high-resolution sonography can depict changes in the nerve's shape and echotexture and can depict many extrinsic causes of nerve entrapment.

High-resolution sonography is capable of depicting peripheral nerves and the brachial plexus. In this study we review the literature on this subject. Normal peripheral nerves have a characteristic echotexture. Most nerves are readily visualized, although this is not always the case with the nerves of the lower extremity. The main pathological changes that can be demonstrated are nerve enlargement and increased hypoechogenicity. In order to demonstrate nerve enlargement, measurements should be performed and compared with a set of reference values. Several neuropathies have been studied by means of ultrasonography. However, many studies concern case reports and show methodological shortcomings. The best studied peripheral neuropathy is the carpal tunnel syndrome in which ultrasonography seems to have an additional value when combined with nerve conduction studies. Nerve enlargement has also been demonstrated in radial neuropathy at the humerus and in ulnar neuropathy at the elbow. The role of sonography in various hereditary and inflammatory neuropathies is uncertain although diffuse nerve thickening could be demonstrated. Further systematic studies are needed to determine the role of sonography in the diagnostic process of the various neuropathies. It would be important to study the subcategories of patients in whom electrodiagnostic studies are normal or show equivocal findings.

Based on a large multicenter experience and a review of the literature, the authors propose a unifying theory to explain an articular origin of peroneal intraneural ganglia. They believe that this unifying theory explains certain intriguing, but poorly understood findings in the literature, including the proximity of the cyst to the joint, the unusual preferential deep peroneal nerve (DPN) deficit, the absence of a pure superficial peroneal nerve (SPN) involvement, the finding of a pedicle in 40% of cases, and the high (10-20%) recurrence rate.

The authors believe that peroneal intraneural lesions are derived from the superior tibiofibular joint and communicate from it via a one-way valve. Given access to the articular branch, the cyst typically dissects proximally by the path of least resistance within the epineurium and up the DPN and the DPN component of the common peroneal nerve (CPN) before compressing nearby SPN fascicles. The authors present objective evidence based on anatomical, clinical, imaging, operative, and histological data that support this unifying theory.

The predictable clinical presentation, electrical studies, imaging characteristics, operative observations, and histological findings regarding peroneal intraneural ganglia can be understood in terms of their origin from the superior tibiofibular joint, the anatomy of the articular branch, and the internal topography of the peroneal nerve that the cyst invades. Understanding the controversial pathogenesis of these cysts will enable surgeons to perform operations based on the pathoanatomy of the articular branch of the CPN and the superior tibiofibular joint, which will ultimately improve clinical results.

A rare cause of ulnar nerve compression at the elbow is presented in this report. A 42 year old right-handed mechanic developed subacute, progressive numbness, tingling and weakness in his right hand. Electrophysiologic studies demonstrated a severe conduction block affecting the ulnar nerve in the retrotrochlear groove but without any sign of major axonal loss. His hand functions were carefully studied prior to surgery. While fine motor tasks were not affected, the hand strength was markedly diminished. At surgery, a 1-cm diameter intraneural ganglion at the site of the conduction block was found and excised. The patient made a dramatic recovery within 6 weeks post-surgery. The conduction block completely resolved and the hand functions also returned to normal. This and other reported cases point to the importance of early diagnosis and intervention.

Medial elbow ganglia have been reported in association with cubital tunnel syndrome. This lesion is thought to occur rarely and has not been emphasized in the literature. The purposes of the present study are to report our experience with this lesion in order to elucidate its prevalence as well as its clinical and radiographic features, to describe our operative findings, and to present the results of surgical treatment.

Four hundred and eighty-seven elbows in 472 patients were treated for cubital tunnel syndrome between 1980 and 1999. We performed a retrospective study of the thirty-eight patients who had a medial ganglion. All of the ganglia were excised, and the ulnar nerve was translocated subcutaneously. Thirty-two patients were followed for a mean of thirty-seven months.

Medial elbow ganglion was the third most common causative factor associated with cubital tunnel syndrome, with an overall prevalence of 8%. Resting pain in the medial aspect of the elbow was reported by twenty-five of the thirty-eight patients, and a sudden onset of numbness in the ring and little fingers or of medial elbow pain without prior symptoms was reported by twenty-nine patients. The symptoms lasted two months or less in thirty-one patients. All ganglia originated from the medial aspect of the ulnohumeral joint, and radiographs of that joint showed degenerative changes in thirty-seven patients. At the time of follow-up, all measurements of sensory and motor function of the ulnar nerve had improved and no recurrence of nerve palsy was found.

Although uncommon, medial elbow ganglia have a strong association with osteoarthritis of the elbow and can cause a relatively acute onset of cubital tunnel syndrome. A patient with cubital tunnel syndrome associated with elbow osteoarthritis who complains of medial elbow pain or severe numbness within two months after the onset of the syndrome should be strongly suspected of having a ganglion. Most ganglia are occult, and ultrasonography and magnetic resonance imaging can assist in the preoperative diagnosis. Careful excision of the ganglion performed concurrently with subcutaneous anterior transposition of the ulnar nerve can produce satisfactory results.

This article describes the use of ultrasound (US) in the evaluation of the elbow. US is able to visualize several abnormalities affecting tendons, muscles, ligaments and bursae around the elbow joint as well as to delineate the nature of soft-tissue swelling, such as a space-occupying lesion or synovial enlargement. Occult fractures, osteophytes and intra-articular loose bodies can be depicted with this technique as well. At the cubital tunnel, US allows accurate imaging of the ulnar nerve and to document changes that occur in compressive syndromes. Over other imaging modalities, US offers several key advantages, including cost effectiveness, availability and ability to perform a dynamic examination of tendon movement and joint motion. With continued experience, it is likely that the use of US will increase further with regards to evaluation of soft-tissue abnormalities of the elbow.

Initial experience with the use of dynamic sonography of the elbow for diagnosing ulnar nerve dislocation and snapping triceps syndrome is reported. Cases of three consecutive patients who underwent sonographic evaluation of the elbow and subsequent open elbow surgery for symptomatic ulnar nerve dislocation were reviewed. Dynamic sonography of the elbow was used to aid in the accurate diagnosis of and differentiation between ulnar nerve dislocation and snapping of the medial triceps muscle.

The diagnosis of nerve entrapment at osteofibrous tunnels relies primarily on clinical and electrodiagnostic findings. Recently, the refinement of high-frequency broadband transducers with a range of 5-15 MHz, sophisticated focusing in the near field, and sensitive color and power Doppler technology have improved the ability to evaluate peripheral nerve entrapment in osteofibrous tunnels with ultrasonography (US). In the upper limb, osteofibrous tunnels amenable to US examination include the carpal tunnel for the median nerve and the cubital and Guyon tunnels for the ulnar nerve. In the lower limb, these tunnels include the fibular neck for the common peroneal nerve, the tarsal tunnel for the posterior tibial nerve, and the intermetatarsal spaces for the interdigital nerves. High-resolution US allows direct imaging of the involved nerves, as well as documentation of changes in nerve shape and echotexture that occur in compressive syndromes. A spectrum of extrinsic causes of entrapment, such as tenosynovitis, ganglia, soft-tissue tumors, bone and joint abnormalities, and anomalous muscles, can also be diagnosed with US. With continued experience, it is likely that this technique will be increasingly used to evaluate nerve entrapment syndromes.

With recent improvements in ultrasound (US) imaging equipment and refinements in scanning technique, an increasing number of peripheral nerves and related pathologic conditions can be identified. US imaging can support clinical and electrophysiologic testing for detection of nerve abnormalities caused by trauma, tumors, and a variety of nonneoplastic conditions, including entrapment neuropathies. This article addresses the normal US appearance of peripheral nerves and discusses the potential role of US nerve imaging in specific clinical settings. A series of US images of diverse pathologic processes involving peripheral nerves is presented.