Partial paralysis of the posterior interosseous nerve caused by a ganglion

Posterior interosseous nerve entrapments: review of the literature. Is the entrapment distal to the arcade of Frohse a really rare condition?

INTRODUCTION

Spontaneous posterior interosseous nerve palsy is a rare condition. Entrapment is mostly at level of the arcade of Frohse, and a few cases of distal entrapment have been described.

METHODS

A case of entrapment distal to the arcade of Frohse is described here. Cases of distal entrapment have been reviewed from the published literature in order to evaluate the frequency of atraumatic mechanical palsy.

RESULTS

Seven cases of distal entrapment have been identified. Lesion is the cause of palsy in 58.7% of the cases and entrapment in 20.65%. The pathology is at the elbow in 33.7% of the cases, at the arcade of Frohse in 28.26%, and at the supinator canal in 10.33%. Entrapment is at the arcade of Frohse in 64.45%, proximal in 20%, and distal in 15.55%.

CONCLUSION

Posterior interosseous nerve distal entrapment is a rare condition; therefore, further investigation is needed when radiological images at the arcade of Frohse do not show any entrapment.

Retrospective Analysis of 20 Patients With Schwannomas: Magnetic Resonance Imaging Characteristics, Pain, and Outcomes Following Excision

A Tinel's sign, a percussion-induced, painful sensation, has been reported as the most useful sign for diagnosing a schwannoma. On magnetic resonance imaging, schwannomas often exhibit a split fat sign and a target sign. The typical treatment for schwannomas is surgical excision; however, excision often results in high rates of neurological deficit. The authors retrospectively reviewed 20 patients who underwent excision of a schwannoma from 2007 to 2015. Twenty patients presented with a split fat sign and 12 patients presented with a Tinel's sign on magnetic resonance imaging. Only 3 patients presented with a target sign on magnetic resonance imaging. The operative approach involved removing the schwannoma, preserving the nearby nerve fascicles, and leaving the epineurium open. Follow-up ranged from 3 to 91 months (average, 29 months). At final follow-up, all patients were pain free. Nineteen patients had normal sensation and full function of their affected limb. One patient developed postoperative posterior interosseous nerve palsy. A Tinel's sign, preoperative pain, and a split fat sign on preoperative magnetic resonance imaging are the clinical symptoms most useful for diagnosing a schwannoma. Schwannomas can be safely removed via intracapsular surgical excision with minimal complications, yielding eradication of preoperative pain, normal sensation, and full function. [Orthopedics. 2017; 40(6):e1036-e1043.].

Spontaneous partial posterior interosseous nerve palsy not caused by an adjacent ganglion

We report a case of spontaneous partial posterior interosseous nerve palsy where the ganglion adjacent to the nerve was not the main cause of the compression. Instead, a thick fascial band deep to the distal edge of the supinator was found responsible. This case illustrates the importance of completing the nerve exploration to fit with the clinical picture.