[The value of wrist arthroscopy in Kienböck's disease]

The integrity of the articular surfaces is of major importance for the prognosis and treatment of lunate necrosis (Kienböck's disease). Though arthroscopy is the most reliable method in the diagnosis of intraarticular pathology it is rarely applied in this condition. The purpose of this study was to evaluate the value of arthroscopy in Kienböck's disease.

20 prospectively evaluated patients underwent arthroscopy for Kienböck's disease. Initial diagnosis was performed by enhanced magnet resonance images, standard radiographies and computed tomography. Preoperative staging was performed according to the MRI-adapted classification of Lichtman and Ross . The arthroscopical measures followed standard procedures. Cartilage lesions were rated by an own modified classification. The wrists were further staged according to an arthroscopical classification system for Kienböck's disease (Bain and Begg ). The posterior and anterior interosseus nerves were resected in all patients and, if necessary, an arthroscopical debridement of the lunate performed.

No clinical or statistical correlation was found between the Lichtman-stages and the distribution and severity of the cartilage lesions. In selected cases severe cartilage lesions (3 degrees and 4 degrees ) were already found in Lichtman-stage IIIA and IIIB, while less severe lesions than expected were observed in Lichtman-stage IV. There was no correlation between the Lichtman-stages and the classification according to Bain and Begg. In selected cases without cartilage lesions carpal collapse (Lichtman stage IIIB) was found. The individual response was unequivocal: Four patients reported minimal, five patients remarkable improvement but all did not demand further procedures. Four patients reported complete relieve. Seven patients demanded further operations (3 proximal row carpectomies, 4 STT fusions). In three of these seven cases the arthroscopical evaluation guided the further operative therapy to appropriate procedures.

In Kienböck's disease arthroscopy more precisely detected alterations of the articular surfaces than radiological diagnostics. Radiological staging over- but also underestimated the cartilage damage. Arthroscopic results strongly influenced the further surgical treatment. Therefore in Kienböck's disease arthroscopy is of high value and recommended.