presentation of biology,biomechanics and practice of intramedullary nailing of long bone fractures by dr mohamed ashraf,govt TD medical college,alleppey,kerala,india
3. *Long bone fracture treatment
*Length ,coronal,sagittal and rotation alignment
*Stable fixation aiming secondary callus healing
*Preservation of blood supply for early union
*Recovery of joint function
4. Nailing=splinting
• No rigid fixation of fragments
• Nailing is internal splinting and semirigid
• Unlocked nailing-3 point fixation
• Locked closed nailing-biological osteosynthesis
• Provide-rotational ,bending and axial stability
• Open and closed nailing
• Relative stability-callus formation
5. Nailing and healing
• Diaphysis needs very strong union
• Callus union is preferred[indirect UNION]
• Soft tissue sleeve and vascularity must be
maintained
• Limited axial micromotion [RELATIVE STABILITY]
• Stress protection and stress osteopenia not
preferred-hence less refracture
• …………..a properly done nailing can do these…
6. Nail-is it a Better implant?
• Biological fixation
• Load sharing implant
• Early weight bearing
• Less stress shielding
• Less implant failure
7. nailing- history
• 1912-Hey groves-IM nail
• 1930-rush-USA
• 1939- herzog
• 1940-kuntscher-modified
• 1950-reamers,locking screws
• 1960-image intensifier
• 1978-grosse-kempf
• 1979- - russel taylor
• 1990- titanium nail
• 1993-AO unreamed nail
8. Nail-types
• Centro medullary-k nail
• Cephalo medullary-PFN
• Condylo cephalic-ender
• Antegrade /retrograde
• Reamed / unreamed
• Dynamic,static,double locked
• 1st gen , 2nd gen , 3rd gen,4th generation
9. Length of nail between the locking
screws
Affected by-fracture type,reaming,interlocking
Reduced working length is preferred for less
bending and torision deformity
Reduced working length-in large diameter nail
in transverse fracture
in reamed nail
Working length
10. Reamed or unreamed
• Reamed nail-destroys medullary blood supply
• but returns by 12 weeks
• Unreamed nail-returns by 6 weeks
-schemitsch et al 1994
• Reaming-may increase periosteal vascularity
• Reaming and nailing-raise compartment pressure
but transient.so critical in already
compromised compartments
- mcqueen 1990,Roger 1992
11. REAMING-EFFECTS
Internal ream grafting possibility
Increased chance of transient
embolism[fat,tumor,sepsis]
Better nail–bone contact
Better bend and torsion resistance
Final 1mm reaming increases
30 % nail contact
12. • Ideally long bone diaphyseal, transverse
or short oblique, closed fractures.
• Medullary cavity-sufficient and
continuous
• Unlocked nail stability-curvature
mismatch
3 point fixation
• If large mismatch - more reaming
• Locked-minimum 2cm between screw
and
fracture[4-5cm
preferred]
21. dynamisation
• Screw removal from long arm
segment
• Only after 6-8-10 weeks
• Load bearing to load sharing
• Compression force at fracture site
• Induce osteogenesis[nail more
biological]
22. dynamisation
• Increases fatigue life
• Do only if fracture sticky
• May lead to shortening and instability
• Hence less frequently used
• Better dynamise after 8-12 weeks
………. wu and chen 1997
23. Pre-op planning
• LIFE FIRST,LIMB NEXT,BONE LAST……..
• GENERAL- polytrauma,chest
injury,metabolic,hematologic,systemic disease
• LOCAL-wound,morel lavalle,
• Nailing-ETC / DCO / ELECTIVE
• Ideal-24-48 hrs
• Delay if chest injury/head injury-fat embolism
• Isolated femoral #-NOT EMERGENCY
• Trauma series x-ray [hip post op also]
24. imaging
• X-RAY - rule of 2
• Implants,old deformities,open physis,normal
bone
• CT – proximal and distal fractures,
pathological#,occult #nof
• MRI-soft tissue ,neurovascular structures
27. table
• Fracture table-problem in poly trauma
problem of neuropraxia
time consuming
no assistant needed for traction
• standard table –assistant manual traction
• standard table-AO distractor aided reduction
1995-karpos et al –no difference in outcome
29. position
• Femur-lateral or supine [sandbag under pelvis]]
fracture table or ordinary table
foot traction [if no injury in area]
pin traction[UT or SC] [if delayed]
limb flexed-40deg for ST # 30 deg for troch#
* Tibia
supine
traction in knee flexion on fracturetabl
leg hanging over end or side
arthroscopic leg holder
30. position
• Supine-easy for surgeon-anatomy,orientation
• obese,easy femur manipulation
• chest,spine,pelvic injury
• happy anesthetist
• Lateral-difficult,valgus drift,better in FFD hip
• Traction- r/o knee injury
distal femoral traction may affect
distal locking
• Too much traction-pudental,peroneal,sciatic palsy
31. Prepping and draping
• Circumferential preparation
• Check c-arm views before draping and
painting
• Tourniquet-more chance of thermal injury
during reaming
32. Incision and entry point
• Incision leads to entry point
• Decided by MOREL lavalle or decubitus ulcer
• Entry point critical to reduce insertional force[hoop]
• Must be in line with medullary cavity if possible
• Tibia and humerus-offset entry cause stress on
posterior and medial cortex
33. Entry point
• Pin placed over entry point.
• In sagittal plane-jn between post 2/3 and ant 1/3
• Incise over pin.
• Pass sleeve over pin
• Remove pin
• Push or twist n push don’t jerk n push
• Stearing bend at 1cm about 15 degree
34. Entry point
• Femur
piriformis [straight]
trochanteric -lateral[>5] or medial[<5]
• Tibia
medial to lateral tibial spine on flat spot
lateral entry better.central/medial cause valgus
tornetta p. et al. JOT 1999
* Humerus-medial to GT outside joint surface
35. Tibia entry point
• Lateral entry point-chance of injury to hoffas pad
and intermenisceal injury
36. Entry point-proximal fractures
• Semi extended position-better Tornetta et al , CORR 1996
• To reduce valgus and extensiondeformity
• Lateral parapatellar approach
• Supra patellar canulated approach
Tornetta p OTA annual meet ,Denver2008
37. Reduction technics
• Reduction must be the first step
• NO implant will reduce the fracture for you
• Use manual manipulation or distractor aided
• Use baton,crutch,half pin joystick,IM reduction
rods,reamer,hooks,pointed clamps etc
• Apply force from post to ant direction at hip
• Flexion 30-40 degree accordingly[IT or ST]
• Traction in neutral or 10-15 deg ER [IT or ST]
• Difficult closed reduction-limited OR
38. Guide wire and reaming
• Avoid bent and twisted guide wire
• Tip may be bent for endosteal deflection[<15]
• Must be centered in AP and LATERAL view
• Buried or impacted in distal epiphyseal scar
• Partial withdrawl before nail impaction
• Complete withdrawl before locking
39. reaming
• Start with smallest reamer
• Check heads-break,defect,bend
• Always ream over guide wire
• Femur-keep close to medial cortex[avoid
posterolateral blowout]
• Low speed power reaming on ball tipped GW
• Exchange with smooth GW before nail insertion
• Mouth overeamed 1-2 mm[hoop stress]
• Remove in clockwise direction
40. Reaming-caution
• If no resistance-reaming proceeded
• If resistance-something wrong
• Fracture site-push
• Comminuted fracture-push
• Segmental fracture-push or hold n ream
41. Nail measurement
• By measuring device
• TMD-between most prominent point of tibial
tubercle and medial malleolus colen et al
• By similar guidewire
• Medial joint line to ankle jointline
• GT tip to superior pole
• Rotational alignment-# line,cortex
thickness,medullary cavity
42. Nailing andlocking
• Proper length and diameter selected
• Assembly and alignment checked
• Initial introduction manually
• Rotate to reduce hoop stress
• Final seating by soft blows
43. locking
• 2 screws or bolts distally and proximally
• Direction varies as per nail and local anatomy
• Distal locked first by free hand or jig[GW sounding]
• Proximal by jig [confirm by GW sounding]
• Screw at proximal part of dynamic hole
• Gap closed by backslapping or telescoping before proximal locking
• Keep 2 threads outside on both side for removal
• Tibia-distal AP locking may injure NVB,so rotate nail internally
Bono c.m et al,journal of Trauma2003
44.
45. Wide medullary cavity
• Reduce by poller screw
• Put before nail insertion on concave side of deformity
• on lateral side of nail path to prevent valgus deformity
• On post side to prevent extension deformity
• Better use bolt rather than screw
• Function as blocking or navigation hence the name
• May cause reaming and nailing problems
• If reamer blocked by poller screw,simple push will do.
48. Fibular #
• If tibia comminuted
• If segmental loss
• If distal fourth #
fix fibula first
49. Open # protocol
• Debride and nail
• Debride absorbable [caso4] antibiotics beads and nail
• Debride PMMA bead EXFIX nail in 2 weeks
• Sequential nailing[ex fix to nail]
• - in less than 2 weeks –less infection
• - in type 3 –preferred[unreamed if primary]
• - in type 1,2 primary nailing preferred
court-brown et al-1990,1991
