Carpometacarpal fracture dislocations of the ulnar rays are rare but complex injuries of the hand and frequently pose a significant diagnostic and therapeutic challenge.

Ulnar impaction syndrome (UIS) is a frequent diagnosis for ulnar-sided wrist pain, traditionally understood as a mechanical overload condition resulting from positive ulnar variance. Established treatments typically focus on osseous decompression, primarily through ulnar shortening osteotomy (USO) or the arthroscopic wafer procedure (AWP).

Ulnarsided wrist pain represents one of the most common problems in hand surgery. Due to the close relationship between the ulnocarpal wrist compartiment, the distal radioulnar joint and its adjacent soft tissue structures numerous pathologies can be the cause for those symptoms. An exact understanding of the anatomic structures and their specific diagnostics is inevitable. The most common sources of ulnarsided wrist pain are instability or osteoarthrosis of the distal radioulnar joint and the ulnocarpal impaction syndrome. The pathologies were addressed with a broad audience during the third web symposium of the German-speaking Working Group for Hand Surgery (DAH) on the 3rd of December 2025. This article summarizes the key messages of the websymposium and provides a guideline for the diagnostics and stage-dependent therapy of the individual pathologies.

Pathological differences at the lunotriquetral junction are frequently missed and confused with other ulnocarpal complaints, as there are scarcely typical clinical and radiological signs.The aim of this manuscript is a summary of the anatomy and pathonanatomy of the lunotriquetral junction as well as of the diagnostical and therapeutical procedures. To these belong beside nonoperative measures reconstructive techniques and salvage procedures.

Fractures of the triquetrum are the second most common carpal fractures after scaphoid fractures and represent a frequent cause of post-traumatic ulnar-sided wrist pain. Dorsal shear fractures account for approximately 93% of all triquetral fractures and are therefore by far the most common fracture type. Two pathomechanisms have been proposed: avulsion by the dorsal ligamentous attachments to the triquetrum and impaction of the dorsal cortex by a prominent ulnar styloid. The dorsal shear/ avulsion fracture is commonly associate with a localized tenderness to palpation over the dorsal aspect of the triquetrum. The diagnosis is confirmed by a lateral wrist X-ray, and, if necessary, also by CT. Treatment is for purely osseous lesions as well as for osteoligamentous avulsion fractures conservative with immobilization in a short-arm cast for 3 weeks. Residual symptoms may persist for several months and are not uncommon. Fractures of the triquetral body are considerably much less frequent and may occur as part of more complex carpal injuries, such as perilunate fracture-dislocations. In these cases, CT is recommended in addition to standard radiographs to accurately define the fracture pattern. Palmar cortical fractures may represent an avulsion injury of the strong palmar portion of the lunotriquetral (LT) ligament. Consecutively, the diagnostic work-up should include magnetic resonance imaging (MRI) in addition to standard radiographs of the wrist. Wrist arthroscopy is the gold standard to confirm an associated LT ligament rupture, followed consecutively by a transfixation of the LT joint.