107 SPECT/CT in post-operative hand and wrist pain Kienböck`s disease Osteomalacia of the lunate or Kienböck`s disease is an avascular osteonecrosis of the lunate. The cause of Kienböck`s disease is still debated but probably multifactorial and influenced by anatomic factors, repetitive trauma and interrupted vascular supply. Additionally, there seems to be an association with ulnar negative variance, where the ulna is relatively shorter than the radius [33]. Kienböck`s disease commonly affects male patients between 20 and 40 years of age. Many patients describe a history of trauma. Local pain, decreased motion, swelling and weakness in the affected hand are typical symptoms. Plain radiographs are negative in early stage, but show sclerosis in progressing stages and collapse/fragmentation in advanced stages. Collapse of the lunate leads to dorsal intercalated segment instability (DISI). MRI can detect early stage Kienböck’s disease by showing decreased T1 signal and missing contrast enhancement [34]. Treatment of Kienböck`s depends on disease stage. Treatment aims are unloading of the lunate, revascularization or restoration of instability and collapse. In stage I conservative treatment is usually attempted. In stage II with ulnar negativity or positivity joint leveling osteotomies like radial shortening osteotomy are performed. Advanced stage III wrists with OA of the surrounding joints are treated by proximal row carpectomy (Figure 6 and 7) and STT or scaphocapitate arthrodesis might be performed with or without lunate excision and graft interposition [35]. SPECT/CT can be used as an alternative to MR for the diagnosis of Kienböck`s disease (Figure 8 and 9). The SPECT part of the study shows the altered radionuclide uptake and the CT part enables the visualization of the integrity of the bone itself [20]. Thus, SPECT/CT can show stage 1 Kienböck`s disease in patients with negative X-rays. After surgical treatment SPECT/CT can be used to assess recovery of the lunate bone metabolism, to evaluate complications like nonunion and to follow the bone integrity. 4