Two cases of pisiform bone impingement syndrome after proximal row carpectomy

Proximal row carpectomy (PRC) is an established surgical procedure used to treat post-traumatic osteoarthritis of the wrist with sparing of the midcarpal joint and advanced aseptic necrosis such as lunatomalacia. Proximalization of the distal carpal row following PRC may lead to secondary problems such as radiocarpal impingement. At follow-up, two of our patients complained about ulnar-sided wrist pain after proximal row carpectomy. Computed tomography (CT) scans were taken for both patients with an additional magnetic resonance imaging scan for one patient. The CT scan revealed clear osteolysis consistent with a pisiform bone impingement on the ulnar styloid process in both the cases, and also on the hamate in one patient. An impingement syndrome of this nature has not previously been described and should be kept in mind when patients report ulnocarpal symptoms after PRC.