Purpose of the study. To evaluate the changes of the wrist by arthroscopy without distraction in patient with multiple hereditary osteochondromatosis (MHO) and enchondromatosis in relation to the forearm deformity and the combination with following surgical procedure.

Introduction. Wrist arthroscopy was used to evaluate the changes in the wrist in patients with MHO and enchondromatosis and to correlate these changes to specific deformities of the forearm bones.

Material and Methods The new technique of wrist arthroscopy without distraction was used in 16 children in 20 wrist joints, with MHO (12 patients) and enchondromatosis (4 patients). Conventional 2.4mm arthro-scope and the III/IV, VI/R and MCU approaches were used in combination mostly with the following surgical procedures according to present deformities (15 times). The arthroscopical findings were correlated to the conventional X-ray examinations of the wrist (radial articular angle, carpal slip, and relative ulna shortening).

Results. 1. Wrist arthroscopy without distraction offers the sufficient information about wrist anatomy in children and it was possible to continue with the surgical procedure in the same session. 2. The arthroscopic findings in the radiocarpal and mediocarpal space were normal in all wrist joints, with exception of one patients with cartilage lesions. 3. The articular disc of triangular fibrocartilage complex failed in 11 wrists, where shortening of the ulna was present or head of ulna was not centred to incisura radii. 4. The normal or reduced disc was found in 5 and 4 wrists, respectively, where ulna was not shortened or where normal position of head of ulna was re-established after lengthening. No correlation was obtained between discus anatomy and radial articular angle and carpal slip.

Conclusions. Shortening of the ulna by MHO or encho-dromatosis leads to elimination of the articular disc and later to degenerative changes in wrist joint. Lengthening of the ulna to distal radioulnar joint leads probably to re-establishment of the articular disc. Arthroscopy without distraction evaluates the wrist conditions and the results of treatment and enables a surgical procedure in the same session in children of the school age.

Purpose of the study. To evaluate the changes of the wrist by arthroscopy without distraction in patients with multiple hereditary osteochondromatosis (MHO), and enchon-dromatosis in relation to the forearm deformity, and the combination with the following surgical procedure.

Introduction. Arthroscopy of the wrist in childhood was not published previously. Wrist arthroscopy was used to evaluate the changes in the wrist in patients with MHO and enchondromatosis and to correlate these changes to specific deformities of the forearm bones.

Material and Methods. The arthroscopy without distraction was used in 11 children in 13 wrist joints, with MHO (nine patients) and enchondromatosis (two patients). Conventional 2.4 mm arthroscope and the III/IV, VI/R and MCU approaches were used in combination mostly with the following surgical procedures according to the presented deformities (11 times). The arthroscopic find-ings were correlated to the conventional X-ray examinations of the wrist (radial articular angle, carpal slip, and relative ulna shortening).

Results. 1. Wrist arthroscopy without distraction offers sufficient information about wrist anatomy in children to make it possible to continue with the surgical procedure in the same session. 2. The arthroscopic findings in the radiocarpal and mediocarpal space were normal in all wrist joints. 3. The articular disc of the triangular fibro-cartilage complex failed in seven wrists where shortening of the ulna was present or the head of ulna was not centered to the incisura radii. 4. A normal or reduced disc was found in six wrists where the ulna was not shortened or a normal position of the head of the ulna was re-established after lengthening. No correlation was obtained between discus anatomy and the radial articular angle and the carpal slip.

Conclusions. Shortening of the ulna by MHO or enchon-dromatosis leads to the disappearance of the articular disc. Centering the ulna to the distal radioulnar joint can lead to re-establishment of the articular disc. Arthros-copy without distraction permits evaluation of the condition of the wrist, the results of treatment, and enables the surgical procedure to be performed in the same session.