Pisiform bone

Abstract: Pain, weakness, and sensory loss occur frequently in the hypothenar eminence. However, clinical examination is difficult and nonspecific, and the prescribed imaging technique may be inadequate, or images may be misinterpreted. Different imaging modalities have various degrees of usefulness for the diagnosis of painful pathologic conditions of the hypothenar eminence. Radiography, multidetector computed tomography (CT), multidetector CT arthrography, and magnetic resonance (MR) imaging of the wrist are useful for surveying the anatomy of the hypothenar eminence, the Guyon canal, and the ulnar nerve and artery and for determining the cause of pain or other symptoms. A fracture of the pisiform bone or the hook of the hamate bone, osteoarthritis or osteochondromatosis of the pisotriquetral joint, Guyon canal syndrome, hypothenar hammer syndrome, tendinopathy of the flexor carpi ulnaris, an anomalous muscle, a ganglion cyst, or a tumor may be responsible for ulnar neuropathy. Specific radiographic views, such as the semisupinated oblique view and the lateral view with the hand radially deviated and the thumb abducted, often provide a sufficient basis for the diagnosis of acute fracture of the hook of the hamate or the pisiform bone. Multidetector CT angiography is an efficient method for diagnosing hypothenar hammer syndrome, and multidetector CT arthrography is well suited for evaluation of the pisotriquetral joint. MR imaging is the modality of choice for depiction of the ulnar nerve.

Abstract: Sixty-seven painful pisotriquetral joints were treated by excision of the pisiform over a 30-year period. Forty-two patients had a previous history of trauma. Ulnar neuropathy was noted in 22 patients, particularly in those with associated wrist-hand fractures and subluxations or dislocations of the pisiform. The abductor and flexor digiti minimi and the palmar carpal ligament with their common fibrous origin were the most common compressing structures on the ulnar nerve. Chondromalacia was found in 29 and osteoarthritis in 20 pisotriquetral joints. Excision of the pisiform provided complete relief of localized hypothenar pain in 65 wrists with no loss of wrist motion or strength. Neurolysis produced full sensory recovery in all 22 patients and full motor recovery in five of six. No late problems associated with the flexor carpi ulnaris tendon were found after excision of the pisiform.

Abstract: The opposable thumb is valuable to man. A thumb in true opposition is not only opposite the fingers, but it is far forward from them and is rotated so that the pulp faces that of the fingers and the nail parallels the palm. Any tenoplasty to produce this must adhere to two essential principles. The tendon must pull subcutaneously in the right direction toward the pisiform bone and it must be inserted in the dorso-ulnar aspect of the base of the proximal phalanx of the thumb to give pronation. This may be accomplished by using any of various muscles for motor power, and for the tendon either the extensor pollicis brevis tendon or any one of various tendons prolonged by tendon grafts. The tendon used is made to pull in the right direction either by passing it through a tendon pulley constructed at the pisiform bone or by passing it around the tendon of the flexor carpi ulnaris.

Abstract: Hypothenar pain was a major complaint in 1.1% of patients 6 months after operation in 500 consecutive carpal tunnel releases. Pain, discomfort, and loss of grip strength was noticed mostly during activities requiring full hand grip or activities associated with use of the heel of the hand, such as pushing up from a chair, or pushing open a door with the flat palm. The pain originated from the piso-triquetral joint, possibly a result of intercarpal alignment change after carpal tunnel release. Pisiform excision was curative, with complete relief of symptoms and return of strength and dexterity. Awareness of this syndrome and systemic evaluation of the piso-triquetral joint preoperatively and postoperatively, as presented here, are essential in the management of this condition.