Comparing scissors and scalpels to a novel surgical instrument: a biomechanical sectioning study

This study introduces a novel surgical instrument to reduce iatrogenic nerve injuries during procedures such as carpal tunnel and ulnar nerve decompression surgery. These injuries often result from direct damage to surrounding tissues by surgical instruments, whose designs have remained largely unchanged over the past decades. The novel device is a modified surgical forceps that has a deployable surgical scalpel that runs along a groove on the forceps. This design protects important anatomical structures while allowing fast dissection and cutting of fascial layers.

The process used to develop a novel instrument included computer-aided design (CAD) modeling, 3D printing for prototyping, and the fabrication of an aluminum prototype. Biomechanical testing was performed with the novel device, iris scissors, bandage scissors, and a scalpel on an MTS Static Materials Test System. The peak force to slide-cut, number of cut attempts, and percentage cut on first attempt were compared between the prototype and traditional surgical tools. The materials cut in testing were Ace™ bandage, stockinette, and gauze. Statistical analyses were performed using Welch's t-tests and Fisher's exact tests.

Compared to conventional bandage and iris scissors, the novel surgical instrument required significantly less force to cut through an Ace™ bandage, stockinette, and gauze (p < 0.01). The number of cuts required to transect those same materials with the novel device was comparable to that of the scalpel and bandage scissors. Additionally, while there were no differences between the novel device and the other devices for an Ace™ bandage and stockinette, the novel device tended to cut a greater percentage of gauze in one pass than did the iris scissors.

The novel surgical instrument designed in this study required less force compared to conventional scissors, demonstrated cutting efficiency similar to that of a scalpel blade, and had more safety features than either instrument. This study highlights the value of collaboration between biomedical engineering and orthopedic surgery departments on innovation in medical technology, through which new technologies with improved design and functionality demonstrate the potential to reduce iatrogenic injuries.