Scapholunate instability remains an unsolved indication in orthopaedics. The Acumed SLIC Screw System is an adjunct to the biological healing of soft tissue repair or reconstructions that treat scapholunate instability. The system includes system-specific instrumentation, a specialized targeting guide, and multiple-size screws to accommodate varying patient anatomy. The Acumed SLIC Screw can be used to hold the reduction of the scapholunate interval while the soft tissue repair heals. The jointed screw allows relative rotation and an anatomic toggle of 15-22 degrees, allowing the scaphoid and lunate to move anatomically while the soft tissue heals.
This animated overview of the SLIC Screw System highlights its use for the treatment of acute schapholunate instability, including features of the SL Targeting Guide for scapholunate reduction and guide wire placement, as well as the SLIC screw itself, an adjunct to the biological healing of soft tissue repair to treat SL instability.
Shown: SLIC Screw in-bone
Mobile devices: tap to show/spin
Cannulated Cylinder-in-Cylinder Screw Design
The patented, cannulated cylinder-in-cylinder design allows the joint of the screw to sit at the SL interval in order to allow maximum relative rotation between the bones. The scaphoid portion of the screw varies in length while the lunate portion is consistent across all three screws. This allows the back end of the screw to sit just below the articular cartilage of the radial side of the scaphoid to aid in screw removal.
To accommodate varying patient anatomy and aiding in soft tissue healing, SLIC Screw is available in multiples sizes with instrumentation specific to each size.
SL Targeting Guide
The SL Targeting Guide allows for targeting different patient anatomy and preparing the carpals for screw insertion. The guide is mostly radiolucent to not obstruct the visibility of the carpals during fluoroscopy. The only metal components are the Scaphoid Needle and the Elevator Screw, which are both positioned on the radial side of the wrist until the K-wire has been inserted across the SL interval.
1. Targeting Wing: Designed to hold the Soft Tissue Protector Cannula in place in order for the Scaphoid Needle to target the location of guide wire insertion.
2. Elevator Screw: Allows adjustment of Targeting Wing to line up with the lateral position of the scaphoid for future 0.045" guide wire insertion
3. Scaphoid Needle: Aids in preventing the 0.045" guide wire from skiving off the scaphoid during insertion and in both the PA and lateral view shows the projection of the guide wire path.
4. Soft Tissue Protector Cannula: Designed with a flat side feature to be used with the Targeting Wing to target the scaphoid and lunate for 0.045" guide wire placement. When the correct trajectory is located, it is locked into place by turning it clockwise.
5. Dorsal Plate: Stabilizes the SL Targeting Guide construct for potential movement during fluoroscopy imaging as well as aid in maintaining placement of the lunate joystick guide wire.
6. Joystick Clip: Aids in anatomical reduction of the scaphoid and lunate by holding the lunate and scaphoid joystick guide wires in reduced position.
The SLIC Screw System provides instrumentation specific to each screw size:
Measurement grooves: The grooves on the SLIC Screw Stepped Drill correspond with the measurements of the screw length.
Hex drivers: The drivers are designed with a step feature to capture both portions of the screw and insert it as one piece.
Easyouts: Three different-size easyouts are included to aid in the removal of the screw after 6-9 months.
For more information about what is included in each procedure pack please see pages 4-5 of the Surgical Technique.