What Is a Locking Suture?

The term locking suture may refer to the stitching pattern used to close a wound or to the design and material of the suture being utilized. Using a locking suture for wound closure contributes to a greater tensile strength in the stitching. These sutures may be made of a stainless steel alloy or an absorbable monofilament thread. A braided thread may also be used in a locking suture pattern. The locking suture is used when the location of the wound or organ being stitched may require extra support, such as the intestines or tendons.

One type of locking suture is made of a monofilament fiber used in the locking-loop method. The thread is knotted at one end of the wound and passed through the tissue. Once the suture is through the skin, it is looped through the visible thread over the top of the wound. The pattern continues until the wound is closed, and then the remaining thread is knotted and trimmed. This pattern of locking stitches is useful for wounds that may be subject to movement or for the repair of internal organs, such as the intestines.

A double-loop locking suture is sometimes used to repair tendons. The double-loop technique increases the tensile strength of the sutured tendon. It is a similar technique to the locking-loop pattern, but the suture is passed through the previously placed loop in two locations. This method usually only fails if the suture thread breaks, which may necessitate a second surgical procedure to repair the wound.

Other locking sutures are made of a stainless steel alloy. These sutures are used to close the sternum after a median sternotomy or lateral thoracotomy. The structure of the material used to make these sutures prevents the stitches from opening due to movement from coughing or breathing. Some patients report that the pain during recovery from these procedures is lessened by the use of steel alloy sutures instead of steel wires.

The stainless steel alloy locking suture allows the surgeon to quickly complete the wound closure. Shaped like a long thin strip of metal with small regularly spaced rectangular openings, the suture is tied by passing the free end through the rectangular opening and pulling the stitch tight. One end of the suture has a needle-like projection, and the other end has a self-locking buckle that prevents the suture from slipping out of place. Unlike other metal sutures, the end can be cut with standard surgical scissors.