Supratentorial Craniotomy Using a Threadwire Saw

An alternative technique for cutting the bone flap in supratentorial craniotomy uses a threadwire saw (T-saw), originally developed for spinal surgery. After placing a burr hole at each corner of the intended craniotomy, osteotomy is performed between adjacent burr holes using a craniotome, leaving a bony bridge of approximately 1/3 of the length of the osteotomy. The T-saw is introduced between adjacent burr holes through the epidural space and the bridge is cut with reciprocating strokes. The narrow beveled cut reduces the bone gap for fitted bone flap fixation. On closure, the bridge firmly supports the flap and only sutures are needed for fixation. A minimal amount of filler is required to fill the bone gap. Successful bone flap fixation was obtained in more than 100 cases. No technique-related complications such as dural laceration or flap displacement occurred. Osteotomy using a T-saw was somewhat time-consuming, but cutting efficiency was improved with a Diamond T-saw, featuring a section of cable covered with diamond particles. This method is ideal for bone cuts in cosmetic cranioplasty; is easy and safe to perform, is inexpensive, and avoids the need for flap fixation with metal devices.