The precise and safe manipulation of surgical instruments is foundational to successful clinical practice. Proper handling is taught early in training to ensure procedural accuracy, minimize tissue trauma, and reduce user fatigue during long procedures. Learning the correct grip maximizes the mechanical advantage, translating subtle hand movements into controlled actions. This approach also helps maintain the sterility of the field and promotes efficiency.
Anatomy and Classification of Surgical Scissors
A standard pair of surgical scissors is composed of four main parts that work together to create the cutting action. The ring handles provide the grip, while the shanks extend to the central pivot point. This pivot, often called the box lock or hinge, joins the two halves and acts as the fulcrum for the cutting motion. Beyond the box lock are the blades, which taper to the tips and perform the actual work.
Surgical scissors are broadly categorized based on their intended function and the shape of their blades and tips. Dissecting scissors (e.g., Metzenbaum or Iris) are typically long and thin, designed for cutting delicate tissues. Heavier operating scissors (e.g., Mayo) are built for cutting tougher materials like fascia, tendons, or sutures. Blade tips are classified as sharp-sharp, sharp-blunt, or blunt-blunt, allowing the user to choose an instrument appropriate for the tissue type. Straight blades offer more mechanical advantage for dense tissue, while curved blades improve maneuverability and visibility in deep cavities.
The Standard Precision Grip: Ring Finger Technique
The most common method for holding ring-handled surgical scissors is the tripod grip, optimized for fine control and stability. To execute this technique, the thumb is placed into the upper ring handle and the ring finger is inserted into the lower ring handle. Only the distal phalanx, or fingertip pad, should be inserted, as sliding the fingers all the way through restricts movement.
The index finger is positioned on the shaft near the box lock or pivot point, acting as a forward guide to stabilize the instrument and direct the blade tips. The middle finger provides lateral support, resting on the lower shank. This four-point contact maximizes tactile feedback, allowing the user to feel the resistance of the tissue being cut. The resulting grip reduces the overall range of motion, which is desirable for intricate tasks like fine tissue dissection or precise suture cutting.
Alternative Holding Methods for Speed and Power
While the tripod grip prioritizes accuracy, certain situations require a different technique where speed or sheer cutting force is needed. The Palm Grip, sometimes called the “Shearing Grip,” is used for cutting dense, non-tissue materials like surgical drapes or heavy sutures. In this method, the instrument’s rings are held within the palm, with the thumb and fingers grasping the shanks.
The palm grip utilizes the larger muscles of the hand and forearm, generating greater leverage and speed than the precision grip. This technique is faster and more powerful, but it sacrifices the fine motor control needed for delicate work. For very small instruments, such as Iris scissors, the instrument may be held between the thumb, index, and middle fingers, similar to holding a pencil, to perform micro-dissection.
Principles of Safe and Effective Cutting
Effective cutting requires the skillful application of mechanical principles and visual awareness. Maintaining a clear line of sight is paramount, meaning the user must always keep the tips of the scissors visible to avoid damaging underlying or adjacent structures. This is particularly relevant when working in deep or obscured surgical fields.
A clean cut is achieved by utilizing the blades closer to the tips, where the shearing force is greatest. Applying counter-tension to the material being cut is a fundamental technique that stabilizes the tissue and prevents it from tearing or slipping. This is often done by gently pulling the tissue with the non-dominant hand or a separate instrument, keeping it taut as the cut is performed. When passing scissors to another person, a safety protocol dictates that the instrument must be passed with the blades closed and the ring handles presented first, ensuring the receiving person grasps the secure end.