At a glance
- Well proven stem design
- Intraoperative interchangeability
- High end surface modifications and materials
- Standard and short version
Philosophy
The 3C hip system employs a straight stem with tapered lateral shoulder, tapered lateral distal stem and proximal coating to encourage proximal bone ingrowth. The profile is straight with a wide proximal M-L dimension to give the implant stability against rotational forces and protects against sinking.
Two stem types for cemented and cementless stems, as well as a short version of the cementless stems allow for optimal adaption to the patients anatomy and bone quality
- Standard stem type with a CCD angle of 131º
- Lateralizing stem type with a CCD angle of 127,5º
- No vertical drop difference
The short (B) version is a shortened standard (A) stem. The cemented version is one size down from the cementless stem. This features allow to implant a short, standard cementless or cemented stem with the same surgical technique, or for a intraoperative change between the 3C variants.
Materials
The following materials and coatings are used for 3C hip stems:
- The cemented stem is made from EndoDur-S (forged CoCrMo)
- The cementless stem is made from Tilastan-S (forged Ti6Al4V alloy)
- Micro-roughness of the stem’s surface ensures primary fixation and is available in PlasmaLink and osteoconductive double coating made from titanium plasma and calcium phosphate (TiCaP)1
This produces a regular and uniform micro structure surface. The distal stem is smooth to discourage bone integration.
Biomechanical properties
- Flattened tapered neck increases the range of motion between stem and acetabular cup
- The highly polished neck area reduces the abrasion of the polyethylene insert if contact should occur2
- Tapered lateral shoulder of the stem allows the trochanter major to remain intact while still providing a wide proximal M-L dimension of the implant - Allows direct anterior approach
- Large anatomical medial curvature provides metaphyseal support, fixation and load transfer. Additionally it ensures good anatomical fit, essential for primary and long term stability
- Tapered distal end prevents bone contact - For the standard length this facilitates introduction of the stem into the medullary cavity
Source
- Khanuja H, Vakil J, Goddard M, Mont M. Current Concepts Review: Cementless Femoral Fixation in Total Hip Arthroplasty. J Bone Joint Surg Am. 2011;93:500-9
- International Orthopedics, Volume 41, Number 3, March 2017, Page 611-618
