MAÏA™ Carpometacarpal Prosthesis

  • The MAÏA™️ CMCJ replacement is designed for the surgical treatment of basal thumb osteoarthritis. 
  • Dual Mobility design to ensure stability and significantly reduce the chance of dislocation.
  • Modern, cannulated instrumentation. 

About MAÏA™ CMCJ Replacement

The MAÏA™ CMCJ replacement from Groupe Lépine is designed for the surgical treatment of basal thumb osteoarthritis. 


  • Dual Mobility design to ensure stability and significantly reduce the chance of dislocation. 
  • Hemispherical trapezium cup available in 8mm, 9mm and 10mm options with 4 pins for primary stability. 
  • 3 sizes of offset modular necks to adjust for soft tissue tension and natural position. 
  • Anatomically designed metacarpal stem with longitudinal stabilisation scales. 
  • Modern, cannulated instrumentation for accurate implantation.
  • Implants have a dual coating of porous titanium and hydroxyapatite for uncemented fixation. 
  • Titanium necks are available for nickel-sensitive patients. 


If you would like more information regarding MAÏA™ CMCJ replacement.

Interested in the MAÏA™ Carpometacarpal Prosthesis?

Get in touch with our experts today to learn more

    Surgical Approach 

    A dorso-lateral approach is required, approximately 3-cm long, centered over the trapeziometacarpal joint. 

    • The incision should be located between the extensor pollicis brevis (EPB) and the abductor pollicis longus (APL). 
    • Start with a rectangular capsular flap with a dorsal hinge to expose the base of the metacarpal, alongside the APL, and then expose the trapezium. Protect the radial artery. 

    For more information on thumb joint replacement surgery using the MAÏA™, download the full surgical technique brochure which includes metacarpal preparation, trapezium preparation, placements, closures and removal of the MAÏA™. 

    The Cup 

    Hemispherical shape made of titanium alloy.  4 polar spikes which ensure primary stability by avoiding rotation of the cup. Excellent equatorial press-fit for initial stability. HA coating for long-term biological fixation. 

    The Neck 

    Made of stainless steel (titanium neck available for nickel-sensitive patients)  The 15˚offset neck helps to preserve the anatomical offset between the trapezium and the 1st metacarpal. 

    The Stem 

    Made of titanium alloy  Available in 4 sizes: 7 (24 mm) 8 (26 mm) 9 (28 mm) 10 (30 mm)  Anatomical shape with a triangular section, a flat dorsal side and a curved palmar side.  Scale-shaped microstructures on the edge of the stem to ensure primary stability avoiding rotation and sinking. 

    This pioneering system from Groupe Lépine is part of a range that also includes 

    COBRA™ Distal Radius Hemiarthroplasty

    The COBRA™ is a hemiarthroplasty prosthesis for conditions of the wrist.

    INCA™ STT Prosthesis

    The INCA™ is designed to treat scaphotrapeziotrapezoid osteoarthritis. It is a resurfacing implant of the distal pole of the scaphoid.
    Groupe Lepine

    Groupe Lépine is a French family company who have been pioneering to be the leading partner of the medical world since 1714. Based in Genay, near Lyon, Groupe Lépine currently operates with 450 working employees across 8 operational sites. Groupe Lépine products are available in more than 30 countries around the world with LEDA being the leading UK distributor of the MAÏA™, COBRA™, INCA™ and MEMOFIX™. 

    Frequently Asked Questions

    Basal thumb osteoarthritis, affects the base of the thumb, at the carpometacarpal joint. The carpometacarpal joint is extremely mobile which allows for movement and motion of the thumb. Over time the joint can be exposed to some wear and tear making the joining less stable and resulting in carpometacarpal joint pain 

    Symptoms of thumb arthritis may include: 

    • Pain at the base of the joint  
    • Swelling 
    • Thumb deformation (usually swan neck or Z deformation) 
    • Weakness in gripping or pinching in everyday activities or motions  

    With any type of osteoarthritis, age is typically the leading cause. Usually as we get older, it becomes more prevalent, but it can affect people from a younger age. Women are typically affected by basal thumb osteoarthritis at a higher rate (about 20%) with less than 5% of men affected by thumb joint arthritis. 

    Surgical and non-surgical treatments are available to reduce pain and tenderness at the base 

    Non Surgical treatment may include: 

    • Physiotherapy 
    • Anti-inflammatory drugs or injections 
    • Resting hand orthosis (thumb or hand support)  

    Surgical procedure 

    After an assessment and the use of non-surgical treatment, surgery may offer the best solution for pain relief including a total prosthesis implant, such as the MAÏA™ Carpometacarpal Prosthesis, to treat the pain in the CMC joint 

    For patient information regarding carpometacarpal prosthesis, you can download the latest patient information booklet 

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