ObjectiveTo evaluate the safety of arthroscopic operation with artificial space on the buttocks for gluteal muscles contracture (GMC) by measuring the plasma osmolarity. MethodsBetween May and June 2011, 30 cases of GMC were joined in the study. Of them, 11 were male and 19 were female with an age range from 4 to 39 years (mean, 24.4 years). Twenty-eight patients had a definite history of repeat intragluteal injection. The disease duration ranged from 1-30 years (mean, 14 years). During operation, normal saline solution was used as lavage fluid, and radiofrequency energy was used as cutter for releasing GMC. The plasma sodium, plasma potassium, blood glucose, blood urea nitrogen concentrations, and plasma osmolarity were compared before and after operation; input and output volume of lavage fluid and intravenous dropping volume were recorded. Whether patients suffered from water intoxication or not was observed. The effect was evaluated through the criteria proposed by XIA Rongxi et al. ResultsThe operation was successfully completed in all patients, who had no water intoxication. The operation time was 16-70 minutes (mean, 33.4 minutes). The input volume was 2-23 L (mean, 6.3 L), the output volume was 2-22 L (mean, 5.8 L), and the absorption volume was 0.1-1.2 L (mean, 0.5 L); and the intravenous dropping volume was 350-1 300 mL (mean, 850 mL). No significant difference was found in plasma sodium, plasma potassium, blood glucose, blood urea nitrogen concentrations, and plasma osmolarity between before and after operations (P>0.05). All patients were followed up 3-26 months (mean, 12.7 months). At last follow-up, according to XIA Rongxi's et al evaluation standard, the results were excellent in 27 cases, good in 3 cases, and the excellent and good rate was 100%. ConclusionArthroscopic operation with artificial space on the buttocks is safe and reliable in the treatment of GMC.