The pisiform forms the ulnar wall of Guyon’s tunnel.
These fractures present with acute tenderness over the pisiform. Palmar midcarpal instability, as described by Lichtman and associates,22 is an example of CIND and is characterized by a volar sag on the ulnar side of the wrist, a clunk that occurs at the end of the range of ulnar deviation with forearm pronation, tenderness over the triquetral-hamate and capitolunate intervals, and weakness of grip. Our approach is to observe whether the fracture is nondisplaced. The cause may be either intrinsic or extrinsic. The job of a ligament is to provide stability at a joint. Two other cases of associated ulnar nerve palsy reported by Howard59 in 1961 and Israeli and associates50 in 1982 spontaneously resolved—one after nonoperative treatment with cast immobilization and the other with no treatment. Most acute pisiform fractures are treated by immobilization with a cast.5 Israeli and associates50 recommended immobilization for 6 weeks. However, these patients typically have tenderness to palpation approximately 3 cm proximal to the pisiform.23. The differential diagnosis of FCU tendinitis includes pisotriquetral arthritis, a ganglion originating from the pisotriquetral joint (or other mass), hamate or pisiform fracture, and ulnar artery thrombosis.25 Patients with calcific tendinitis often present with pain, swelling, and localized tenderness to palpation, which can include erythema in the affected area.
what should i do? Conservative treatment is a thumb spica cast for 4 to 6 weeks for a nondisplaced fracture.11. There may be ulnar nerve symptoms such as numbness and tingling in the little finger and along the outside of the ring finger. The incidence of isolated acute lunate fractures is low.4 The mechanism of injury with lunate fractures is axial loading by the capitate to the body of the lunate.14 Treatment for a nondisplaced acute lunate fracture includes cast immobilization for 6 to 8 weeks with repeat radiographs to assess healing.7 Displacement of lunate fractures greater than 1 mm warrant open reduction and internal fixation (ORIF).15. Jacinto Orozco MD, Ghazi M. Rayan MD, in Principles and Practice of Wrist Surgery, 2010. Pisiform fractures may be associated with triquetrum, hamate, or dorsal radius fractures. Terri M. Skirven, Lauren M. DeTullio, in Hand and Upper Extremity Rehabilitation (Fourth Edition), 2016, Fractures of the pisiform occur from trauma associated with direct force to the proximal palmar hypothenar surface of the hand/wrist or from forced contraction of the flexor carpi ulnaris (FCU). Or if you have a specific question or concern about this or any aspect of your or your family’s health, you can get back in touch via our Ask the Expert service, available around the clock, 365 days a year, whenever and wherever you need us. Be aware that pain is frequently an ongoing problem and the possibility of refracture always exists with the carpal bones.28 Therefore, restoration of ROM and strength should be within the client’s pain tolerance, and aggressive therapy should always be avoided. They suggested that resolution of the palsy without surgery is unlikely to occur inside Guyon’s canal in the presence of a compressive lesion such as that caused by fractured fragments.  In mammals and non-human primates, the pisiform is an enlarged and elongated bone that articulates with the distal ulna. In addition, pisiform fractures are missed because they are difficult to see on routine radiographs of the wrist.