BACKGROUND: Poly (glycolide-co-L-lactide) (PGLA) braided regeneration conduits have been shown to be biocompatible for the repair of damaged nerve. Mechanical properties, such as radial compression and torsion, greatly influence nerve regeneration and functional recovery. OBJECTIVE: To observe the influence of conduit parameters and coating methods on torsion properties in an in vitro-degradation environment and at normal temperature. DESIGN, TIME AND SETTING: An in vitro, comparative study using repeated measures was performed at the College of Textiles, Donghua University, China from January 2005 to December 2007. MATERIALS: PGLA fiber and yarn (Shanghai Bio-TianQing, China), as well as torsion property testing instrument (LaiZhou Electronic Instrument, China), were used in the present study.METHODS: A total of 16 types of conduits were constructed according to braiding structures (regular /triaxial), angles (50°/55°/60°/65°), and coating methods (coated/uncoated). At normal temperature, torsion properties of all conduits were tested at a predefined constant angle of 90°. Coated and uncoated conduits, which were triaxial and 65°, were incubated in a 5% CO_2 incubator at 37 °C to simulate an in vitro degradation environment, and then torsion properties were tested at 4, 7, 11, 14, 17, 21, 24, and 28 days in culture. MAIN OUTCOME MEASURES: Maximal torsion strength and torsion strength-torsion angle curve of conduits at normal temperature, as well as torsion strength-torsion angle curve, loss of torsion strength, and change in maximal torsion strength in an in vitro degradation environment.RESULTS: At normal temperature, the torsion properties of the triaxial structure were superior to the regular structure. Coated conduits performed better than uncoated ones, and the larger braiding angles exhibited superior torsion properties (P < 0.05). In the in vitro degradation environment, with degradation time, torsion strength of uncoated conduits was deceased gradually and the loss of torsion strength was increased fast. Torsion strength of coated conduits was increased first and decreased afterwards; the loss of torsion strength was decreased slowly till 14 days; both became identical after 14 days (P > 0.05).CONCLUSION: Torsion properties of coated conduits with a triaxial structure and large braiding angle were superior to uncoated conduits with regular structures and small braiding angles.