Stryker Hansson Pin System User manual

5
•Slipped Capital Femoral Epiphysis
Operative Technique
Hansson™Pin System
Pediatrics

2
Contents
Introduction and Rationale 3
Relative Indications & Contraindications 4
Features & Benefits 5
Operative Technique
Patient Positioning 6
Reduction 7
Optional Stabilization Guide Wire Insertion 8
Determining the Incision and Insertion Points 9
Skin Incision and Guide Wire Insertion 10
Drilling and Measurement 11
Instrument-to-Pin Assembly 12
Insertion of the Hansson Pin 13
and Activation of the Hook
Instrument Removal 14
Postoperative Regime 15
Pin Removal 16
Ordering Information
Implants 17
Instruments 18
References 19

3
Introduction
The Hansson™ Pin system, designed
by Professor Lars Ingvar Hansson at
the University of Lund in Sweden,
was developed based on research
concerning the effects of implants on
the blood supply to the femoral head.
Specifically developed for the
treatment of slipped capital femoral
epiphysis, the Hansson Pin system has
been designed to minimise surgical
trauma to the patient and offer secure,
stable fixation with reduced risk of
healing complications for all grades
of fracture.
Twenty years of successful clinical
studies have been carried out to
enhance the Hansson™ Pin System
to its current form.
This work is summarized in 6 theses
and more than 70 published articles.
Rationale
The methodology involves a cylindrical
pin inserted in a drill hole which
attaches to the femoral head via a hook,
providing strong, stable fixation
through a simple and precise procedure.
The drill hole and pin run at right
angles to the growth zone and are,
depending on the degree of slipping,
relatively centrally located in the
femoral neck and head.
The pin is 10-20mm longer than the
drillhole toallow continued growth
in the length of the femoral neck.
Slips of up to 60° can be stabilised
byosteosynthesis.

4
Relative Indications & Contraindications
Slipped Capital
Femoral Epiphysis
Adult Femoral Neck Fractures
The physician’s education, training and
professional judgement must be relied
upon to choose the most appropriate
device and treatment.
Conditions presenting an increased
risk of implant failure include:
•Any active or suspected latent
infection or marked local
inflammation in or about the
affected area.
•Compromised vascularity that would
inhibit adequate blood supply to the
fracture or the operative site.
•Bone stock compromised by disease,
infection or prior implantation that
can not provide adequate support
and/or fixation of the devices.
•Material sensitivity, documented
or suspected.
•Obesity. An obese patient can
produce loads on the implant that
can lead to failure of the fixation of
the deviceor to failure of the device
itself.
•Patients having inadequate tissue
coverage over the operative site.
•Implant utilization that would
interfere with anatomical structures
or physiological performance.
•Anymental or neuromuscular
disorder which would create an
unacceptable risk of fixation failure or
complications in postoperative care.
•Othermedical orsurgical conditions
which would preclude the potential
benefit of surgery.
Detailed information is included in the
instructions for use being provided
with each implant.
See package insert for a complete list
ofpotential adverse effects and
contraindications. The surgeon must
discuss all relevant risks, including the
service life of the device and the need
for postoperative protection of the
implant with the child’s parents,
when necessary.
Relative Contraindications
Contraindications
Indications
Due toalackof any supportive
clinical experience, the Hansson Pin
is not recommended for use with
paediatric hip fractures.

5
Features & Benefits
Preventing diastasis and further
displacement of the epiphysis
The risk of further intraoperative
displacement of the femoral head is
reduced by drilling a channel for the
Hansson Pin with the femoral head
fixed with kirschner wires. The smooth
outer pin allows the surgeon to gently
push the implant through the channel,
reducing the risk of diastasis between
the femoral neck and the head.1
Lasting stable fixation
The hook resists loosening of the
fixation to the femoral head as the
longitudinal growth of the femoral
neck retracts the pin in the channel
thereby stabilizing the femoral head.
Loosening of the implant is potentially
reduced because of resorption and
growth of the femoral neck under
normal conditions.1
Reducing the risk of unequal
bone length
The continued growth of the femoral
neck in cases with Slipped Capital
Femoral Epiphysis is an indication
of undisturbed intra- and postoperative
vascularization, as the nutrition for the
proliferating cells of the growth plate
is provided by the epiphysial vessels.
By preserving the blood supply,
the Hansson Pin System reduces
the risk of unequal bone length.1
Easy extraction
The risk of the pin being trapped in
the bone is reduced as the pin surface
is smooth. The hook is easily
withdrawn back into the body of the
pin, which can then be removed.1
Frontal view Lateral view
Slipped Capital
Femoral Epiphysis

6
Operative Technique
Step 1 - Patient Positioning
Correct positioning of the patient
on the fracture table is essential for
avoiding problems and complications
during surgery (Fig. 1).
Place the patient in supine position
on the fracture table.
Healthy side: Position the leg on the
healthy side with the hip in flexion
and slight abduction so that the C-arm
can be adjusted intra-operatively for
both the anterior/posterior and the
lateral/medial views. This is necessary to
obtain a true lateral view of the femoral
neck and head (Fig. 2). The purpose of
this view is to avoid the penetration of
the end of the pin through the surface
of the femoral head.
Furthermore, again for avoiding pin
penetration, the surface of the femoral
head must beseen continuously when
moving the C–armfromthe horizontal
position to the vertical position.
Slipped side: Position the hip in full
extension with neutral position
between abduction and adduction.
Fig. 1–Position Patient; C-Arm in A/P View
Fig.2–Position Patient; C-Arm in L/M View

7
Operative Technique
Step 2 - Reduction
Apply the surgical boot to the foot.
Mild traction is applied for the sole
purpose of maintaining the leg in the
horizontal plane. Additional support
under the thigh may be necessary.
Rotate the foot internally by 30-60°
and fix in position. This is so that the
femoral neck is parallel to the radiation
beam in the lateral view (Fig. 3).
Stable (Chronic) Slips
Eighty to ninety percent of slips are
stable (or chronic).
Stable slips are always pinned in situ.
Any attempt to perform a closed
reduction on a chronic slip may lead
to avascular necrosis.
Gradual bone remodelling has taken
placeas a response to the insidious
slipping of the femur away from
the femoral head. (Fig. 4) This is
the body's natural attempt to adapt
the geometry of the proximal femur
in ordertomaintain a functional hip
joint. The remodelling is therefore
ossifiedand reductionis not possible.
The stable slip is pinned with the
intention of preventing further
slippage, as well as preventing the
possibility of acute-on-chronic
traumatic changes, which could be
devastating for the vascularization
of the femoral head.
The surgical treatment of a stable slip
can therefore be planned in advance
but must be considered urgent.
Fig. 3 – Internal Rotation of the Hip
Fig. 4 – Bone Remodelling
30- 60°
Unstable (Acute) Slips
Unstable slips (where the event is
recent, the child cannot weight-bear
and the threat of avascular necrosis
of the femoral head is an immediate
danger) must be pinned without delay
from the moment of the patient's
arrival in the clinic.
This is an emergency situation.
Some chronic remodelling may be
noted on X-ray and again, this ossified
modification of the hip joint cannot be
reduced in surgery.
The acute or unstable portion of the
slip is treated with closed reduction
byinternal rotation and then pinned.
The chronic portion is left as it is.

8
Step 3 – Stabilization Guide
Wire Insertion
When treating unstable (acute)
slips
aGuide Wire may be used.
Using biplanar floroscopy, it is inserted
percutaneously in the trochanteric
region into the femoral neck and
head for intraoperative stabilization.
(Fig. 5).
Fig.5
Operative Technique

9
Step 4 – Determining the Incision
Point and Implant Position
Slipping of the femoral head occurs
in a true posterior direction.
The Hansson Pin must be positioned
in the central part of the femoral head.
To achieve this, the pin must be
inserted anterior-laterally in the
greater trochanter and then directed
posteriorly (Fig. 6).
Aprerequisite for being able to
correctly position the Hansson Pin
is to insert a Ø2.4mm Guide Wire
prior to drilling.
Guide Wire Insertion Point –
Anterior/Posterior View:
Position a Guide Wire on the skin
of the anterior aspect of the thigh.
Verify by anterior/posterior
fluoroscopy that the Guide Wire
is in the correct position in the central
part of the femoral neck and head
(Fig. 7). Mark the position of the
Guide Wire on the anterior surface
of the thigh.
Lateral/Medial View:
Now position the Guide Wire over the
skin onthe lateral aspect of the thigh.
Verify by lateral/medial fluoroscopy that
the Guide Wire has been positioned to
enter posteriorly towards the central
part of the femoral head (Fig. 8)
Mark the position of the Guide Wire
onthe lateral aspect of the thigh.
The intersection of these two lines at
the anterior-lateral aspect of the thigh
at the level of the lesser trochanter
represents the optimal point for
percutaneous insertion of the Guide
Wire (Fig. 9).
Fig. 6 – Final Implant Position to Achieve Fig. 8 – L/M X-Ray of Guide Wire over skin
Fig. 7 – A/P X-Ray of Guide Wire over skin
Fig. 9 – Incision and Guide Wire Insertion Point
Operative Technique

10
Step 5 – Skin Incision and Guide
Wire Insertion
Make a 20mm incision at the site
where the two lines on the thigh
intersect. The insertion point on the
anterior-lateral face of the proximal
femur is identified at the level of the
lesser trochanter (Fig. 10).
If harder cortical bone is anticipated
(such as with a child being treated
with chemotherapy), the surgeon may
prefer to pre-drill the cortex with the
optional drill.
Insert the Guide Wire over the Guide
Wire Bush and Drill Sleeve. Using a
power drill, begin insertion from the
anterio-lateral cortex, crossing the
epiphysis and targeting the center of
the femoral head. According to the
severity of the slip, the guide wire will
bein an oblique positionin the
femoral neck.
Use frequent biplanar fluoroscopic
control to verify the alignment of
the GuideWire in both the anterior/
posterior and lateral/medial plane.
This is to ensure that the centre of the
femoral head will be reached.
If the direction of the Guide Wire
appears to deviate from the centre
ofthe femoral head, stop the
procedure, remove the Guide Wire,
and recommence until correct
positioning of the Guide Wire is
obtained (Fig. 11). Advance to within
5mm of the subchondral bone to
anticipate the necessary space for the
hook to be extruded.
Remove the Guide Wire Bush.
Fig. 10 – Skin Incision
Operative Technique
Fig. 11 – Guide Wire Insertion Final Implant Position toAchieve