Suture bridge and other suspensory fixation methods typically refer to constructs that consist of a very strong piece of suture between two different structures. In the case of Lisfranc injuries this suture bridge holds the medial cuneiform and second metatarsal together.
The suture bridge itself can be held in place with either a metal plate sitting against the bone or with a screw in the bone. Suture bridge constructs are very versatile, and can be used in a number of ligament and tendon reconstructions as well as bony fixation.
Treatment of these injuries varies based on how the Lisfranc ligament is disrupted: either a tear in the ligament itself or fractures in the bones around the ligament. Lisfranc injuries with fractures can usually be treated with fixation with plates and screws, while purely ligamentous injuries have typically been treated with fusion procedures in order to get the injury to heal.
However, advances in suture bridge technology has led to the use of these constructs to fix the Lisfranc ligamentous injuries. Fixation with a suture button construct has the theoretical advantage of allowing some motion across the Lisfranc joint which is thought to be more consistent with the joints normal anatomy.
Fixation of the Lisfranc foot fracture or ligament injury is typically performed through an incision between the first and second toes at the level of the midfoot, centered over the joint between the second metatarsal and medial cuneiform. The joint and any fractures are placed back into their normal position, and fixation occurs through one of three methods: fixing with plates and screws, fusing, or fixation with a suture button construct.
Plate and screw fixation can be performed with several different shapes and sizes of plates, with the ultimate goal of returning all joints and fractures to normal position. Fusion can be performed with either plates and screws with larger screw down the middle of the bone.
Suture button fixation is performed by drilling a hole between the second metatarsal and medial cuneiform in line with the joint. A suture button is passed through this hole and tightened to ensure secure fixation. After all of these forms of fixation, patients are placed into a splint or a boot and are not allowed to put weight on their foot for upwards of 2 months.
Lisfranc injuries describe a disruption of the Lisfranc ligament that connects two bones (the medial cuneiform and the second metatarsal) in the middle of the foot. These injuries can vary widely in how severe they are from severe dislocations and fractures that break through the skin to subtle injuries that can be missed for long periods of time.
Patients typically sustain this injury after sustaining a large load through their foot in a plantar flexed (toes pointed down) position. Swelling, bruising, and pain typically occur. Xrays will typically show widening between the second metatarsal and medial cuneiform, however more subtle injuries may only be visible on a CT of MRI scan. Almost all Lisfranc injuries with displacement of the bones are fixed as this instability can lead to severe pain and disability.
The Arthrex InternalBrace system is a very versatile suture bridge construct consisting of very strong FiberTapeTM between a metal plate known as a cortical button and a bone anchor. In Lisfranc fixation the cortical button is passed through to the far side of the second metatarsal and the anchor placed in the medial cuneiform.
The suture is tightened in order to reduce and fix the injured joint. One of the major benefits of this construct is the lack of large plates or screws which can cause pain and may need to be removed at a later date. This procedure may also be performed through much smaller incisions than traditional methods, again leading to less pain.