37 and 38 - Internal Fixation I and II Flashcards
Fixation vs prolonged splinting/traction… Prolonged immobilization can cause…
o Soft tissue atrophy (the muscle will get smaller from disuse – called cast disease)
o “Cast disease” of the bone
o Disuse atrophy
History
- 1907 – Basic principles 1st described by Lambotte
- 1949 – Dr. Robert Danis wrote The Theory and Practice of Osteosynthesis (Developed the coapteur)
- 1958 – AO (Arbeitsgemeinschaft fur Osteosynthesefragen) group formed (15 general and orthopedic surgeons from Switzerland)
AO principles
- Anatomical reduction of fracture fragments
- Stable internal fixation designed to fulfill local biomechanical demands (absolute stability not always necessary)
- Preservation of the blood supply to the bone fragments and soft tissue by means of atraumatic surgical technique
- Early active pain-free mobilization of muscles and joints adjacent to the fracture, to prevent cast disease – this is really important ***
Blood supply during bone healing
o Endosteal or medullary vessels (Inner 2/3 to 3/4 of cortical bone) o Periosteum (outer 1/3 of cortical bone) o Notes: do NOT want to take off a lot of periosteum to get the fixation on the bone because it will disrupt the healing of bone***
Indirect osseous repair bone healing
Indirect osseous repair (occurs when you have a little bit of motion present – micromotion) o Inflammation (1-7 days) o Soft Callous (~3 weeks) o Hard Callous (3-4 months) o Remodeling (months-years)
Direct osseous repair bone healing
Direct osseous repair (occurs when there is absolute stability of the bone – no micromotion)
o Bypasses callous formation – NO CALLUS FORMS
o “Cutting cones” form at areas of direct contact
o Gap healing (deposition of lamellar bone at 90 degrees to fracture)
o Not necessarily better or stronger, but it can be better than having a really large callus
Internal fixation - absolute stability
Absolute stability – NO motion at fracture site
o Compression plates or screws
o Ideal for articular fracture (a fracture on the articular surface of bone where you do NOT want callus formation because it will cause arthritis/joint problems w/ callus formation)
o Needs
Internal fixation - relative stability
Relative stability – varying degrees of motion
o IM nailing, ex fix, locking plates
o Holds fracture fragments in place, but will likely heal with callous
o Needs 2-10% strain (over 10% will NOT be stability – then there is risk of non-union)
Definition of strain
o Deformation of a material when a given force is applied
o Relative change in fracture gap divided by fracture gap
o Strain = change L/L x 100%
Elongation at rupture
o Lamellar bone (2%)
o Granulation tissue (100%) – A LOT MORE FLEXIBLE ***
Decrease strain by…
o Increasing gap length
o Decreasing motion
Video of strain model
- Strain occurs when you have deformation of tissue in the gap
- The change in length and initial length allows you to calculate strain
- When comparing a small gap vs a large gap, the small gap does not have
as much surface area - With a small gap and compression, you will achieve absolute stability,
no movement, low strain on the gap and therefore direct healing - With a small gap and no compression, you will achieve relative stability,
but with movement there will be high strain on the gap and therefore
poor healing - With a large gap (comminuted fracture), you get bridging which leads to
relative stability, but you get soft tissue structures helping, so there will
only be low strain with movement leading to indirect healing via a callus
Key characteristics of ideal implant material
o Biocompatibility (decrease reactivity)
o Strength
o Resistance to degradation and erosion (all metals corrode!)
o Ease of integration
o Minimal adverse effects on imaging (can see healing well)
Two main metal products for internal fixation
- Stainless steel
- Titanium
Stainless steel
o Corrosion products (Nickle (Ni), Chromium (Cr), Molybdenum (Mo))
o Can cause pain, inflammation, allergic reaction – especially with Ni**
Titanium
o Titanium particles
o Possible foreign body reaction of osteolysis – not as much irritation or allergy as steel
o Not as hard as stainless steel, so non-compliant patients can break them
Description of titanium
Least dense of surgically implantable metals
o Titanium: 4.5 g/cm3
o Stainless steel: 7.9 g/cm3
o Cobalt chromium: 8.3 g/cm
Used for patients with nickel allergy
Cobalt chromium
- Increased tensile strength
- Increased fatigue resistance
- Material of choice for joint implants
Mixing metals - galvanic corosion
- Galvanic corrosion: when a metal corrodes preferentially to the other based on its properties
- In Theory this occurs due to differing electrochemical potentials in metals
- The least noble metal will corrode
- STUDY – Hol et al.J. Injury. 2007 showed no difference in corrosion when mixing metals
Parts of the screw
o Head: the head of the screw is a little rounded
o Shaft: no thread
o Shank: threading
o Runout: where the shaft and shank come together = WEAKEST PART OF SCREW***
o Pitch: distance between each individual thread
o Thread angle: how much each of the threads angles out
o Inner core diameter: how wide the distal core is
o Outer core diameter: how wide the threads stick out
o Tip: end of screw, past area with thread
Tops of heads of screws
o Different screws have different shapes and therefore require different screw drivers
o More and more companies are going away from the cruciate or cross-shaped screw head and more toward the star shape so that the screw driver does not strip the screw
o Sometimes you need to go in and take the screws out, so then you will need to make sure you have the right screw driver on hand
Runout example
- Since the runout is the weakest point of the screw, you never want that to be the point that is at the surface of the bone, either entering or exiting
- This is because that point of the screw will have the most force applied to it and it is therefore more prone to breaking during weightbearing
Screw types
- Cortical or Cancellous
- Fully threaded or partially threaded (typically cancellous, but there are hybrids too)
- Self-tapping or non-self-tapping
- Cannulated or solid
Cortical screw
Used for cortical bone
o Smaller pitch for grasping cortical bone
o 1.25 mm thread pitch
o Fully threaded
Cancellous screw
Used for cancellous bone
o Larger pitch, 1.75 mm
o Thin core, deep threads with different tip
o Fully or partially threaded (more common)
Compression lag screw by TECHNIQUE
o Overdrill (glide hole)
o Under drill
o Countersink
o Measure
o Tap (if necessary) – most now are “self-tapping” so they can cut their own threads
o Compression by technique, uses a fully threaded screw
Compression lag screw by DESIGN
o Compression by design uses a partially threaded screw
o The threads will catch past the fracture gap, but you have no thread above that
o Compressing force is coming from closer to the tip of the screw where the threads are
Terminology - Glide hole/overdrill
Glide hole and overdrill synonymous with each other
o Larger drill that usually matches screw outer diameter (outer core)
Terminology - Guide hole/thread hole/underdrill
Guide hole, thread hole and under drill synonymous with each other
o Smaller drill that matches screw core diameter (inner core)
Instruments needed for lag technique
- Overdrill (larger)
- Under drill (smaller)
- Countersink (create divot for head of screw)
- Measuring device (hook on tip, 2 mm increments)
- Tap (if necessary)
Steps for insertion of a lag screw BY TECHNIQUE
- Glide hole – go through proximal cortex, feel the “pop,” then stop
- Thread hole – this one goes all the way through to the far cortex
- Countersink – turn it back and forth to create the divot
- Depth gauge – do you depth gauge to see how long of a screw you need
- Tap – if necessary
- Insertion of screw
Explanation of a guide hole for lag screw by technique
- Left: the guide hole important if you want to gain compression so you don’t get threads caught in the gap or fracture site (you will get distraction instead of compression)
- Right: here we see no threads caught in the fracture sit and we get the threads pushing up from the bottom and the screw head pushing down to establish good compression of the fracture site
Uses of a cortical screw
Cortical screw – fully threaded lag by TECHNIQUE
o Bunion correction in the neck of the first metatarsal
o Primarily cortical bone here, so we would use a cortical screw, using lag by technique
Uses of a cancellous screw
Cancellous screw – partially threaded lag by DESIGN
o Hallux IPJ fusion correction in the distal hallux
o Primarily cancellous bone in the center of the bone, so we would use a cancellous screw, using lag by design
Steps of insertion of lag screw by DESIGN
- Thread hole – smaller drill ONLY, you skip the initial step of the glide hole because there are not threads on the upper part
- Countersink – turn it back and forth to create the divot
- Depth gauge – to know how long of a screw you need
- Tap – if necessary
- Insertion of screw – to achieve the compression
- Threads need to cross fracture or osteotomy site, otherwise distraction occurs
Example of lag screw by DESIGN
- Medial malleolar fracture
- When placing a screw into the tibia, this portion of the bone is
mostly cancellous, so we would use a partially threaded screw
and achieve compression using lag by design
Screw placement for lag by DESIGN
Threads need to cross fracture or osteotomy site otherwise distraction will occur
o Unacceptable – you will get distraction
o Okay, but not ideal – the screw can break because you are right at the runoff
o Ideal – go from opposite direction so you get the appropriate threads going across fracture site
See image in handout
Lag screw depth for lag screw by TECHNIQUE
o Need to insert 1mm past far cortex to increase “pullout” strength
Lag screw depth for lag screw by DESIGN
o Do not want to pierce far cortex because they are cancellous screws
AO screw sets - 3 basic sets
Mini fragment set = 1.5mm, 2.0mm 2.7mm
- Forefoot procedures (match size of screw to the size of bone you are repairing)
Small fragment set = 3.5mm, 4.0mm
- Midfoot or fibular fractures
Large fragment set = 4.5mm, 6.5 mm
- Used for hindfoot or tibial fractures – calcaneal osteotomy***
Example of mini fragment set
- A lot of times everything will be labeled and well organized
- Includes screw drivers for all the screw heads, measuring device, soft tissue protector, etc.
- Sometimes there are numerous layers of the tray with additional tools you can use
Mechanical forces
- Bending
- Torsion – twisting forces
- Shear – sliding back and forth
- NOTE: these are the forces we are trying to COUNTERACT when we do internal fixation
Charnley’s fracture classification
Stable fracture
o Transverse fracture
Unstable fracture
o Oblique or spiral fracture
o Comminuted fracture
Potentially stable fracture
o Short oblique fracture
NOTE: this will become important when you start putting your screws in because you will want to consider what forces you are trying to limit by your screw placement
Interfragmentary screws
Perpendicular to bone
o Maximum resistance to shearing forces***
Perpendicular to fragment
o Maximum inter-fragment compression forces***
NOTE: if you can do one of each, a lot of times that is the most stable
Principles of lag screw technique diagram
- A. To determine best location and inclination, forceps temporarily
compress fracture - B. Lag screw replaces forceps in location and position (inclination)
- C. Lag screw is best positioned at right angle to fracture plane.
Use of bisecting angle is correct only for osteotomies with less
than 40 degrees of inclination. For example, if inclination is 60
degrees, osteotomy will be displaced because of insufficient
inclination of lag screw.
Screw orientation for spiral fracture
Diagram 1
- If you have a spiral fracture, that goes all the
way around the bone, ideally you would follow
the fracture down the bone and fixate it along
the entire fracture
- This isn’t always feasible due to the soft tissue
constraints (this is where plates can be helpful)
- But here we can see correct vs. incorrect screw
placement – need to insert screw perpendicular to
the fracture in order to achieve direct compression
Screw orientation for spiral fracture continued
Diagram 2
- Here we have a long oblique fracture with
screw placements
- Note that we are placing screws perpendicular
to the long axis of the bone in the middle screw
- Also note the other two outside screws are
placed perpendicular to the fracture line
Self-tapping screw
o Cut own thread path
o Fluted tip
o Decrease # of steps of screw insertion
o Increased torque required for insertion
o Weakened pull-out strength at fluted areas (17-30 less)
o Not recommended for inter-fragment fixation (AO/ASIF)
Non self-tapping screw
o Blunt tip (no flutes)
o Require thread holes (cortical bone)
o Less axial load and torque required
o Ideal for inter-fragment compression
Cannulated screws
- Cannulated means there is a hole in the center of your screw –have become very population
- Reduced thread to core ratio
- Decreased pull-out strength (not enough for people to stop using them)
- Simple application
- Wide variety of sizes (3.0, 3.5, 4.0, 4.5, 5.0, 6.5, 7.0, 7.3, 8.0mm)
Alternative screws
- Absorbable
- Hebert screw
Absorbable screw
Not as common because they are not very strong)
o Natural = allograft
o Synthetic = polylactic acid / polyglycolic acid
Hebert screw
o Two sets of threads
o Can be cannulated
o Decrease pull-out and compressive forces
o Good in areas where screw head prominence may be problematic
K wires - smooth vs threaded, common sizes
o Threaded allows greater purchase in the bone
o Threaded breaks more easily
Common sizes
- 0.035, 0.045, 0.054, 0.062 inches in diameter
K wires are used for…
o Stabilization of hammer toe procedures
o Stabilization of osteotomies (usually in a crossing fashion)
NOTE: Don’t want to use wire larger than 1/3 of the diameter of the bone, could cause fractures
Steinman pins
- Same as k-wire except larger and only comes smooth
- Most common sizes: 5/64, 3/32, 1/8 inches
Use to
o Stabilize larger osteotomies or fusion – calcaneus or ankle
o Can be used as a metatarsal intramedullary nail
o Smooth K-wire or Steinman pin fixation of choice across growth plate
Cerclage wiring/monofilament wire
- Cerclage: Encircling of a part with a ring or a loop
- Thin malleable stainless steel wire (Size: 30-18 gauge
Cerclage wiring/monofilament wire uses
Useful for
o Moderately comminuted metatarsal fracture
o Transverse osteotomies
o Tension band wiring
o Plan “B” or “C” when other hardware methods fail
Don’t want to bend or flex too much, will weaken the wire and cause failure
Tension band wiring
- Uses K-wire with cerclage wire
- Generally 1-2 K-wires placed across fracture in parallel fashion and monofilament wire placed in a figure 8 pattern to exert force opposite of fracture fragment
Used in fracture with
o Stable soft tissue attachment
o Fragments that may be too small or difficult to put a screw through
o Screw can be used in this technique but not usually in the foot
Tension band principle
- Offer TRUE dynamic compression
- Ideally you want to have a nice central load, you don’t
want to have that eccentric where you are getting
distraction on one side - If you do have an eccentric load, you want a conversion
via a pulley system to convert the distraction force into
all over compression force
Tension band video example
- Elbow fracture example because it has a tendon attached to it
- Again, ideally you want to have central compression, but due
to the tendon attachment, you will get an off-centered or
eccentric load - In order to convert these forces, you put you wire across the
fracture in order to get that pulley system and good compression
all the way across
Staple fixation
- Resist distraction but generally not shearing or bending forces
- Traditional staples offer little to no compression
New staple technology = “memory staples”
o Made out of special alloy nitinol
o Compress with body heat or with heat source such as electrocautery
o Must be careful not to touch with hands when putting in
Plates
Traditional plate – there are 4 different functions you can achieve with this: o Compression o Neutralization o Buttress o Bridge
Locking
MIPO
Plate compression
- Eccentric drilling
- Pre-bending
- Tension device
- Tension Band
Eccentric drilling
- The most common way you can achieve compression by using a plate is by eccentric drilling
- Some of the plates you see don’t have a nice round hole – can be oval with a little slope
- When you’re drilling for holes, drill away from fracture site, so that way when you drill for your actual screw, it is rotating toward the fracture site and achieving compression
- There are specialized drills that help us achieve this depending on if you are drilling in the center of the hole (neutral position) or on one side or the other (dynamic compression position)
Pre-bending
- Another way to achieve compression is pre-bending the plate (does not work for locking plate)
- You bend the plate a little bit so that when you are putting the screws in, it forces the fracture site together as you push down on the screws
- This is useful in a transverse fracture or an osteotomy
- Need to insert initial screws close to the fracture site (no far away on each side) in order to avoid the top pulling apart and the bottom pulling together – “gapping”
Tension band
- If there is tension on the bone, you will want to keep in mind what side is the tension side and which side is the compression side corresponding to the forces of each side
- Place plate on the tension side so you’re helping to hold the bone together, not the tension side
- If you place the plate on the compression side, you will be contributing to gapping on the tension side of the bone
- Even though podiatrists may want to place these plates plantarly, it is nearly impossible due to soft tissue and muscle attachments, so you will need to do dorsal plates regardless of forces
Tension device
- Not common – has never used one or seen one
- You can put your screw into the unstable portion of the fracture, apply compression to the fracture site, then put the other screw in to secure the plate while there is compression on the fracture site
DCP (dynamic compression plate)
o Screws can be eccentrically drilled
o Creates compression
o Total bone plate contact
o Can create osteonecrosis under plate
LC-DCP (limited contact dynamic compression plate)
BULKIER
o Creates compression across fracture without bone-plate compression
o Limits vascular trauma
Functions of a nuetralizing plate
o Helps protect inter-fragment screw
o Neutralizes forces to prevent rotational forces
o Example: spiral fibula fracture
Functions of a buttress plate
o Stabilizes fracture
o Anchored to main stable fragment, not necessarily to fragment it is supporting
o Example: tibial plateau or plafond fracture
o Usually metaphyseal or epiphyseal
o Calcaneal fractures
Functions of a bridge plate
o Plate fixated in two main fragments only
o Used to hold bone out to length
o Due to comminution
o Example: surgery with graft placement
Biologic osteosynthesis
- Out to length
- Restore axis
- Restore rotational alignment
- Respect fragment biology
Locking plates
- Newer technology with threaded holes
- Screw locks into plate for extra point of contact
- “The internal, ex-fix”
- Stability is not dependent on plate bone compression - Reduces osteonecrosis
LCP - locking compression plate
- Has combination of locking hole and compression hole
- There is a spot for a traditional screw as well as a locking screw
Angle dependence in locking plates
- Locking plates are angle dependent***
- If you tilt the screw a little bit one way or another, it loses its “lock” and screw can come out
- More than 10 ° deviation reduces push out force by 77%
Rules of stabilization
- Screw Fixation
- Plate Stability
- Vassals Rule
- Two Screws are Better than One Large Screw
Screw fixation
o The length of the fracture should be at least twice the diameter of the bone involved
o This is for if you want to use screw fixation ONLY
Plate stability
o Metatarsal plates need 4 cortices, 2 screws on both sides of fracture
o Ankle plates need 6-8 cortices, 3-4 screws
Vassals rule
o Reduce the primary fracture and secondary fractures spontaneously reduce
Two screws are better than one large screw
o 2 points of fixation to resist rotatory forces
o Resists rotatory force
o 1st screw perpendicular to cortex: anchor
o 2nd screw perpendicular to fracture line: compression
o If you can only insert one screw, insert it half-way
Rules of stabilization
- Select the correct screw and placement of the screw for the type of bone you are in
- The “rule of cortices” means that you use cortical screws or cancellous screws and do not let your screw pierce the far side of the bone to go into a joint
Traditional vs locking screw
- Bicrotical – pierces the near and far bone cortex
- Unicortical – inserts into the near cortex, but does not exit the far cortex
- NOTE: either way with your locking plate, you will be using unicortical screws which only enter the bone, they do not exit the far side of the bone because you already get the extra point of fixation within the plate itself
LCP recommendations
- Apply plate to bone as closely as possible
- For lower extremity fracture, 2-3 screws is sufficient on either side of the fracture
- Longer plates offer more stability - If using short plate, you may want to add more screws to offer more stability
- Apply screws as closely to fracture as possible if comminuted fracture - Omission of 1 hole, Reduced axial stiffness by 64%, Reduced torsional stiffness by 36%
- If simple fracture may want to omit 1-2 holes near fracture to prevent excess stiffness
Vassal rule
If you reduce the primary fracture, the secondary fractures will reduce as well. See diagram:
o A. Pre-reduction radiograph
o B. Post closed reduction radiograph
o C. Lateral view showing relative reduction of posterior malleolus fracture (Volkman’s fracture) following bimalleolar ORIF (Vassal’s principle)
o D. Mortis view showing intact mortis
o D&E. ORIF with lateral fibular plate, inter-fragment screw, and 2 malleolar screws.
MIPO - minimally invasive plate osteosynthesis
Percutaneous plate usually used in tibia or the femur
o Anatomically pre-contoured
o Usually will be a locking plate
Used to protect fracture biology (minimally disruptive to soft tissue and Periosteum)
o Plate can “hover” over the bone
Internal fixation complications
- Prominent painful hardware = most common
- Hardware breakage
- Hardware backing out
- Malunion
- Nickle allergy
- Sterile abscess or reaction
- Infection
- Delayed union or non-union
Prominent painful hardware
- Particularly with fibular plates and plantar calcaneal screws
- Incorrect screw length
- Screw pierces far cortex and irritates soft tissue
Hardware breakage
- Patient noncompliance
- Not ideal hardware placement
- Run-out on osteotomy or fracture line
- Hardware not big enough or stiff enough to resist forces
Hardware backing out
- Screws not placed tightly enough or locking screw did not get locked
- AO techniques not used appropriately
- Soft or osteoporotic bone (more common in middle aged women, but men as well)
Malunion – loss of correction of fracture to osteotomy
- Screws not placed at appropriate angle
- Plate not long enough or not enough screws used
- Patient noncompliance
- Incorrect procedure choice
- Fracture or osteotomy fixated in a misaligned position
Nickel allergy
- Will see continued erythema after incision heals
- May see lack of bone healing or osteolysis
Sterile abscess or reaction
May be seen with bioabsorbable screws
Infection
- Generally if using hardware, use preop abx to decrease or prevent
- 2 gram Ancef IV
- if Penicillin allergy, 1 gram Vancomycin IV or 600 mg Clindamycin IV
- If using Vancomycin, infuse slowly to prevent “red man syndrome”
- Leave hardware in if stable, take out if unstable (don’t always need to take it out)
STUDY – Surgeon error
Bone model study where they performed intentional errors on 3.5 and 4.0 mm screw insertion and looked at effects of pullout strength
Stripping screw (over tightening) on insertion
- 82% reduction of pullout strength (huge reduction in strength of fixation)
- Also tested packing hole with graft as a salvage and reinserting screw
- 79% reduction of pullout strength (helped a little, but not a whole lot)
Using 3.5 mm drill for pilot hole for 3.5 screw (should be smaller)
- 76% reduction of pullout strength
o Use of incorrect tap
- 1-12% reduction of pullout strength (did not make that much of a difference
Using WRONG DRILL or STRIPPING THE SCREW (overtightening) decreased strength***
Delayed union and non-union
- Delayed union: Fracture not healing in expected time for fracture type, location and patient age
- Nonunion: Fracture exists and healing has stopped
Causes of delayed union or non-union
- Vascular disruptment - Fracture location (5th met Jones), periosteal stripping, PVD (peripheral vascular disease)
- Mechanical instability (your fixation isn’t holding things)
- Excessively rigid fixation (fixation is too tight, there is no micro-movement to stimulate healing)
- Noncompliance - Walking too soon, smoking, poor diet, neuropathy
CASE I
- HPI: 43 y/o female presents with dorsolateral left 5th met pain. Had tailor’s bunionectomy previously by another doctor, continues to have severe pain. Patient also relates history of multiple ankle sprains with history of ankle ligament reconstruction that didn’t help much.
- PMH: Hypothyroidism, HTN, Arthritis
- PSH: Left Taylor’s bunionectomy 8 months ago, L lateral ankle reconstruction 1996
- ROS: Neuro - +for tingling, burning and numbness to left LE, M/S - + for multiple herniated disks and L knee pain
- Meds: Ranitidine, Levothyroxine
- Allergies: Latex – rash and edema, Nickel – rash, Adhesives – rash
- SH: 48 pack/year history of tobacco, Housewife with 7 children
- NVSI B/L
- Derm: Scar on lateral left ankle and 5th MPJ
- M/S: Significant pain with palpation of 5th met head with prominent exostosis noted. + inversion, limited eversion, Significant knee valgus with WB b/l left worse than right, Calcaneal varus b/l left worse than right
- Patient had previous x-rays done at a local hospital
- Previous records reviewed - Patient had an oblique osteotomy with titanium snap off screw
Case study 1 - What contributed to the hardware failing?
o Weightbearing, non-compliance, hypothyroidism, smoking, only 1 screw, poor location of screw placement, should not be right at the edge, hx of calcaneal varus, more pressure on 5th metatarsal, etc.
Case study 1 - Assessment
o Diagnosis = Painful exostosis left 5th metatarsal secondary to hardware failure and loss of correction of 5th met osteotomy
o Calcaneal varus
Case study 1 - Plan
Exostectomy and hardware removal of left 5th met with possible 5th met osteotomy
- Couldn’t find screw because it was buried in bone
- Just cleaned it up and closed that location
Calcaneal osteotomy to correct varus deformity
- Eventually the screw started to back out and became painful, so they removed it
- Probably hadn’t gotten the screw tight enough
CASE STUDY II
- 60 year old female underwent closing base wedge osteotomy, akin and hammer toe procedure for severe right bunion and hammer toe deformity
- Is not diabetic but does have mild neuropathy
- Also has knee problems on the left and is obese
- 6 weeks post op: she arrives walking (supposed to be on crutches) and toe is sticking straight up
- Wedge was overly aggressive, non-compliance contributed to hardware failure
- External fixation was then implemented for a more stale construct and she could weight bear
CASE STUDY III
HPI o 61 year old diabetic male o complains of bunion deformity and limited range of motion o Has peripheral neuropathy o It was decided to 1st MPJ arthrodesis
Post-op course
o Patient allowed to weight bear in the boot
o He didn’t always wear in the house
o May have been doing range of motion exercises
Post-op: revision surgery, used a plate instead for more stability and an external fixator
CASE STUDY IV
HPI
o 45 year old diabetic male
o Chronic ulcer under 1st metatarsal head due to plantarflexed 1st ray
o Jones tensuspension performed
o Hallux IPJ arthrodesis with EHL tendon transfer to 1st metatarsal neck
Intra-op
o 4.0 screw was intended to be placed
o 3.0 screw was handed over instead
Post-op
o Patient instructed to be nonweightbearing
o Came in with no crutches to postop appointments
o Within 2 weeks screw was backing out of his hallux and was removed in clinic
Went back in and put a much stronger screw
