The United Orthopedics Locking Cage is utilised for clinical cases with severe acetabulum deficiency, to reconstruct the acetabular structure before the joint prosthesis is mounted on. The Locking Cage consists of a locking cage main body (diameters in 50~70 mm increments) and required bone screws (lengths in 15~75 mm increments) for basic fixation.
The hook (3 sizes) and ischial flange (1 size) are modular designs for optional use when demand for extra stability exists. The auto break-off locking nut is the key item to complete the locking mechanism, converting the bone screws from its original compressive function to a locking type function.
Locking Screw Design
The poly-axial bone screw is designed to provide flexibility selecting the optimal direction for screw insertion. In addition, the unique locking nut provides enhanced stability for the fixed structure by converting the compression screws into locking screws.
The locking nut features a hexagonal head design to improve usability intra-operatively and includes a break-off mechanism designed to act as a torque-limiter for optimised locking strength and to avoid a ‘cold-welding’ effect between screw threads.
Proven Safety and Stability
The Locking Cage is designed for optimal stability to ensure successful acetabular cage fixation in patients with a damaged acetabulum, to ensure osseointegration is achieved between host and graft bones in a stable environment and to help restore ideal joint biomechanics.
After securing the locking nuts in the Locking Cage, the inserted bone screws and the Locking Cage form a stable construct designed to greatly enhance structural stiffness against physiological compressive load. This reinforced structure can further protect the graft behind the Locking Cage from the threat of resorption due to excessive compression load.