Described herein are a group of degradable, thermoplastic polymers, which are able to change their shape after an increase temperature. Their shape memory capability enables bulky implants to be placed in the body through small incisions or to perform complex mechanical deformations automatically. The shape memory polymers are preferably biocompatible and can be biodegradable or non-degradable polymers. Preferably, the biodegradable polymer has a linear degradation rate. In a specifically preferred embodiment, the suture is formed of biodegradable polymer capable of forming a self-tightening knot. In a most preferred embodiment, the suture is used to close a wound or body scission.