A suture anchor is a small device used during surgical procedures to attach soft tissue, such as ligaments and tendons, to bone. The size and type of anchor needed to secure the soft tissue is dependent on the density of the individual patient’s bone and the operation being performed. Suture anchors may be made of titanium metal, polyetheretherketone thermoplastic, or biodegradable absorbable material. They are commonly used as part of a rotator cuff repair surgery.
The suture anchor can be made in two different shapes. A screw-in anchor looks very similar to the bottom half of a normal household screw, with two tiny eyelet holes at the top through which the suture material is connected. The lodging-type anchor has the same two eyelet openings at the top but does not have ridges around the body of the device.
Inserting the suture anchors into the bone is done in two different ways, depending on the type of anchor being used in the procedure. The screw-in suture anchor is twisted into place with an instrument called a suture anchor driver. Comparable in appearance to a screwdriver, the tool is used to insert the anchor into a pre-drilled hole in the bone. The lodging type anchor is carefully pushed into the pre-drilled hole with an insertion tool equipped with a special handle. Drivers and insertion tools vary in size according to the dimension of the anchor being used in the surgery.
After the suture anchor has been correctly placed into the bone, a braided or monofilament suture is threaded through the small eyelet at the end of the anchor. Soft tissue is then attached to the suture thread and fixated to the anchor implanted in the bone. The surgeon will knot the loose ends of the suture near the anchor point for greater stability of the soft tissue repair.
Complications from the use of suture anchors are more common near active muscle sites and when used in soft bones. The most common problem that occurs is when the suture anchor comes out of the bone, also called an anchor pullout, which usually happens when the smallest sized anchors are used. A problem with the polymer-based plastic anchor may happen if the eyelet of the anchor breaks. Titanium metal suture anchors have sometimes broken sutures during excessive physical activity. Occasionally, repeat surgery may be required if the suture anchor moves or is not correctly positioned.