JUST ASM frmoral stem---TI+HA coating stem
Dec. 21, 2021
ASM is an acronym derived from A Stem of Multi-Function,Intended to provide a variety of combination of functions,Provides more flexibility for doctors in their surgical planning.
1.1 Indications
Developmental Dysplasia of the Hip(DDH)
Osteoarthritis of the hip
Primary degenerative osteoarthritis of the hip
1.2 Contraindication
osteoporosis
Severe stenosis of the medullary cavity
Severe femoral shaft atrophy does not provide reliable fixation of the revision prosthesis
2.1 product features
① Proximal triangular cuff design
lThe sleeve is conical and protrudes a triangle to one side, this design provides an oval locking on top of the sleeve, Thus the cuff can be tightly pressed and fixed in the epiphysis of the upper femur to provide rotational stability。
② Taper locking of sleeve and handle body
lMorse taper connection relies on the mechanical friction force generated by the taper wall corresponding to the handle body and sleeve to achieve the effect of cold welding, so as to reduce the fretting of the base and effectively resist rotation
③ Distal spike design
The elongated lateral ridge design with eight protrusions at the distal end provides rotational stability of the femoral shaft
④ Sleeve coating step design
lThe ring shear stress is changed into axial compressive stress, which improves the axial stability of the handle and prevents the handle from sinking
lIncreased bone contact area with the proximal femur (13%), providing a wider integration interface and better osseointegration results
lEffectively prevent debris from wear into the medullary cavity and reduce the possibility of osteolysis and loosening due to debris disease after surgery
⑤ Sleeve Ti+HA double coating
lPlasma sprayed Ti coating features:High binding strength, good biocompatibility, no biological activity (No direct osseous binding with bone tissue)
lPlasma sprayed HA coating features: good biological activity, but poor bonding strength with substrate titanium alloy
lHA+Ti has high binding strength (The mismatch of thermal expansion coefficient between HA and matrix can be alleviated),Surface roughness, good biological activity
lPlasma spraying has the advantages of fast coating formation, high temperature to completely dissolve HA, high bonding strength, low porosity, low residual stress and high coating quality
⑥ Sleeve and handle body separate assembly
lFor example, the length of lower limbs can be adjusted through the head-neck taper connection, and the femoral anteversion Angle can be adjusted through the neck-stem taper connection(Adjustable by 360° rotation)
3. case share
case 1
case 2