chronOS™
Trauma and Orthopaedic Applications
Synthetic cancellous bone graft substitute
(-tricalcium phosphate)
High tibial osteotomy
Chronos wedges provide optimised
scaffold for bone ingrowth
Original Instruments and Implants of the Association
for the Study of Internal Fixation – AO/ASIF
chronOS™ case study
High tibial osteotomy:
optimised scaffold for bone ingrowth
Select Chronos wedge
Preoperatively, select a Chronos wedge
that matches the angle of the correction
gap. Chronos wedges are available
in the 3 angulation sizes 7°,10° and 13°.
Prepare Chronos wedge
Take 5 –10 cc of autologous blood. To
achieve osteogenic potential, autologous
bone marrow may be used.
Transfer the autologous blood to a
disposable 50 cc syringe. The opening of
the syringe must be kept closed.
Small pieces of Chronos may absorb
blood, without applying vacuum from a
syringe.
Enclose Chronos wedge and pump 3–5
times for an even perfusion. This
allows the pores of Chronos to be filled,
thus enhancing the rapid exchange
of fluids in vivo and thereby initiating the
remodelling process.
Warning
This description is not sufficient for immediate application of the instrumentation. Instruction by a surgeon experienced in handling this instrumentation is
highly recommended.
Insert Chronos wedge
The wedge can be inserted before or
after fixation. Alternatively, half of the
wedge can be inserted before fixation
and the second half after. Always maintain the correction gap with a bone
spreader until the gap is internally fixated.
With forceps, insert the narrow part of
the wedge first.
Note: No pressure should be applied on
Chronos as its mechanical compressive
strength is similar to that of cancellous
bone.
Very gentle taps with a hammer may be
necessary to achieve a press-fit of the
Chronos wedge in the correction gap.
When a press-fit is achieved, cut off the
protruding aspect of the Chronos wedge.
Always make sure that the Chronos
wedge is aligned with the cortex.
Technique tips
The Chronos wedge can be split with a
chisel and a hammer if necessary.
The Chronos wedge can be shaped with
an oscillating saw or rasp before or after
insertion.
chronOS™
Trauma and Orthopaedic Applications
Synthetic cancellous bone graft
substitute (-tricalcium phosphate)
Remodels
Replaced by bone in 6 –18 months
Easy to use
Anatomically shaped, sterile packed and
available in three different sizes
Mechanical properties
The compressive strength of Chronos is
consistently 7.5 ±1 MPa, which is similar
to that of cancellous bone.
Note: The use of Chronos is restricted to
applications with minor loading, unless
supported with internal fixation devices.
High tibial osteotomy
Post-op 3 months
Post-op 12 months
Post-op 6 months
Printed in Switzerland
GRA
Post-op 6 weeks
Subject to modifications.
Medial fixation with a TomoFix™ plate
and correction gap filled with Chronos
wedge, male patient, 30 years old.
chronOS™ wedges, semicircular
710.057S angle 7°, size 25357 mm
710.060S angle 10°, size 253510 mm
EU authorized representative:
Mathys Medical Belux N.V.-S.A.
B-1000 Brussels
Distributed by: Stratec Medical
Eimattstrasse 3, CH-4436 Oberdorf
Presented by:
0123
Art. No. 036.000.308 1/03
Manufacturer: Mathys Medizinaltechnik AG
Güterstrasse 5, CH-2544 Bettlach
© Stratec Medical
710.063S angle 13°, size 253513 mm