Basic Information
Pain, instability, and reduced motion of the basal thumb joint (CMC I) may be caused by rheumatoid arthritis, primary osteoarthrosis and secondary arthrosis due to fracture of the first metacarpal or trapezium.
Traditionally, these problems have been treated operatively by CMC I fusion or different kinds of resection arthroplasty. The strength of the thumb is less after resection arthroplasty, and reduced stability in the basal joint may be a problem.
Different types of total CMC I-prostheses have therefore been developed. When successful, total replacement of the basal thumb joint affords the best solution in that it provides the patient with a strong, stable, mobile and pain free thumb.
A high frequency of loosening of both uncemented and cemented prostheses has been reported.
The MOTEC® basal thumb joint prosthesis has been designed to overcome the problems of loosening and subluxation by improving short term fixation, optimizing long term fixation and osseointegration, reducing the risk of osteolysis and minimizing the risk of procedure related complications.
However, we promote caution and emphasize the importance of patient selection based on functional demand.
The MOTEC is a modular prosthesis consisting of four parts, providing the surgeon with 168 combinations replicating the patient’s normal CMC-1 joint range of motion.- Trapezium threaded implant (3 sizes + 3 XL sizes).
- Trapezium Cup
- Metacarpal head implant (4 sizes)
- Metacarpal threaded implant (5 sizes + 2 XL sizes).
Key Features
- The implant has a collar.
- The articulation is metal against metal with ball and socket articulation made of cobalt chrome molybdenum alloy treated with chromium nitride.
- Fixation is achieved by threaded implants made of titanium alloy, blasted and coated with Bonit®, which is a resorbable calcium phosphate combination with proven osteoconductive properties.
- Range of motion (ROM) 120°
Indications
Improved short term fixation
- Immediate primary fixation is achieved by threaded implants.
- A collar prevents the trapezium implant from pivoting sideways or sinking.
- The design of the threaded trapezium implants has been optimized for maximum bone purchase.
- The threads of the conical metacarpal implant engage into the cortical bone of the intramedullary canal, preventing the implant from sinking.
Optimized long term fixation and osseointegration
- Optimal blasting of titanium alloy implants improves long term fixation and osseointegration.
The titanium surface is blasted with extra pure Al2 O3 using a specific technique and to a specific roughness value to maximize the bone ingrowth. - The titanium alloy threaded implants are coated with Bonit®, a resorbable calcium phosphate combination with proven osteoconductive properties, improving long term fixation.
- Cementless – eliminating potential cement related complications.
