Ch 63 Tibia fracture Flashcards
tibia fracture
- majority are diaphyseal fractures.
- 10-20% are open fractures
- repair procedure depends on: type/location of the fracture, age, open fractures, economic, surgeon’s preference
- overall prognosis following fracture of the tibia and fibula is generally good
What major muscles attach to the tibia and what is their function?
Quadriceps femoris (stifle extension)
Biceps femoris (stifle flexor)
Caudal part of sartorius (stifle flexor)
Cranial tibial muscle (tarsal flexor)
tibia/fibula muscles
- semitedndinosus, gracilis, sartorius
- peroneus
- popliteus
- digitial extensor/flexor
Fibula
fibula serves as an attachment site for a few muscles and for collateral ligaments of the stifle and the tarsal joints
List the 4 epiphyses of the tibia
Proximal epiphysis
Tuberosity epiphysis
Distal epilphysis
Medial malleolar epiphysis
What is an apophysis?
A traction epiphysis such as the tibial tuberosity
How much of the longitudinal length of the tibia is from the proximal and distal epiphyses respectively?
Proximal 40%
Distal 60%
At what age does the tuberosity epiphysis fuse with the proximal epiphysis?
At what age does the tuberosity physis normally close?
Fuses to proximal epiphysis 5-9m in large dogs
Physis closes over 12m in large dogs
At what age does the medial malleolar epiphysis fuse to the distal epiphysis?
Very early, approx 4-5m in large breeds.
What part of the tibial plateau is articular?
The caudal 1/2
What muscles attach to the tibial tuberosity? (3)
Quadriceps femorus - patella ligament
biceps femoris
sartorius
tibia ad fibula anatomy
Tibia
- tibial body is three sided proximally
- distal half is essentially cylindrical
- S- shaped
- distal part of the tibia forms the articular surface and the medial malleolus.
- medial malleolus = attachment of the medial collateral ligament of the tarsocrural joint.
Fibula
- head = attachment of the lateral collateral ligament of the stifle
- form the lateral malleolus = attachment of the lateral collateral ligament of the tarsus
What are the main vessels which supply blood to the tibial and fibula?
Tibia
- Cranial tibial artery
(turns into nutrient artery and the periosteal vessels)
Fibula
- Cranial tibial artery (head)
- Peroneal artery (fibula)
tibial bone blood supply
- nutrient artery divides into proximal and distal branches that anastomose with the metaphyseal arteries at each end
- These anastomoses permit the metaphyseal arteries to sustain the medullary arterial supply when the principal nutrient artery is disrupted
- The medullary arteries supply the inner two-thirds of the tibial cortical circulation
- periosteal arteries supply the outer one-third of the cortical circulation
What vessels and nerves surround the tibia
medial
- saphenous artery and vein
- saphenous nerve
lateral and caudal
- Tibial and popliteal artery
- Peroneal and cutaneous nerves
Fracture Epidemiology
- Open fractures accounted for 12% of diaphyseal fractures and 37% of distal fractures
- Proximal region, diaphyseal, and distal region fractures accounted for approximately 1%, 83%, and 18% of fractures
Proximal Region
- Tibial tuberosity avulsion
- physeal fracture (Salter-Harris type I or II)
- articular surface only 2%
Diaphysis
- mid-diaphysis most common location
- Oblique/spiral fractures and comminuted most common
Distal Region
- Physeal fractures
- medial or lateral malleolus (Salter-Harris type I or II)
successful fracture management
biology (5) , mechanics (3), clinical (3)
biologic factors
- age
- health
- blood supply
- soft tissue damage
- location of the fracture
mechanical factors
- type/stability of the fracture,
- size and activity of the patient,
- number of limbs injured
clinical and practical factors
- financial constraints,
- patient and client compliance,
- surgeon’s preference
pre-op
- stabilise
- manage open fracture
- assess neurologically
- rads
Fractures of the Proximal Region of the Tibia
- generally involve the physis in young animals and the metaphysis in mature animals
- approach: medial, lateral (Care not to damage the tendon of origin of the long digital extensor muscle during elevation of the cranial tibial muscle)
Avulsion of the Tibial Tuberosity
- usually between 4 and 8 months of age
- large dogs the growth plate associated with the tuberosity closes late in development
- normally wide growth plate in the immature animal for a fracture; therefore radiographs of the opposite limb should be taken for comparison
What can result in a tibial tuberosity avulsion?
Contraction of the quadriceps while the stifle is flexed and the foot is firmly on the ground
What is Osgood Schlatter disease?
Considered to be a form of osteochondrosis but has been suggested that it should be classified as a minimally displace tibial tuberosity fracture
What leg position can aid in reduction of a tibial tuberosity fracture? What are the repair options?
Hip flexed and stifle extended
Repair options:
- cast if minimally displaced, small-breed dog, 2-3 weeks
- 2 K-wires in a caudoproximal direction (very young small dogs with minimal displacement)
- Pin and tension band (preferred)
- Reattachment of patella tendon to bone tunnel if not enough bone to reattach
large and medium breeds < 6 months old, and small breeds < 4 months old
- the fixation should be removed as early as possible
- when clinical and radiographic union
- avoid premature fusion of the tuberosity to the shaft and distal translocation of the tuberosity.
tuberosity can fragment easily in young
complications of tuberosity avulsion
- reavulsion,
- wire or pin breakage,
- bending of a pin,
- pin migration,
- entry of a pin into the proximal epiphysis,
- deformity of the proximal tibia.
Premature closure of the apophyseal growth plate and deformity of the tibial tuberosity are common
prognosis for normal function is generally good.
Fractures of the Physis
- Salter-Harris type I or II
- combined proximal epiphysis and tibial tuberosity are usually involved
- may be accompanied by collateral ligament damage
What are the repair options for a proximal physeal fracture?
Pinning!
- At least 2 cross pins
- Third pin through tuberosity recommened for better stability
- gentle levering of the epiphysis onto the metaphysis may be necessary
- prognosis for normal function is generally good.
Fractures of the Metaphysis
- If the proximal segment is displaced, it tends to tilt caudal
- most cases an open approach is indicated for reduction and fixation.
- craniomedial (more common) or craniolateral approach is made over the proximal end of the tibia
What are the repair options for proximal metaphyseal fractures?
IM pin, cross pins, plate, lag screws
If fibular head had detacted from tibia, should be reattached with screws
If comminuted, plate must be placed on side of comminution to act as buttress plate
approach to proximal tibia
Fractures of the Diaphysis
- account for 70% to 80% of all fractures of the tibia.
- Oblique and spiral fractures are the most common
What is the ideal pin insertion point for normograde tibial IM pinning?
What is the recommended size?
- Approx 1/3 - 1/2 distance from cranial tibial tuberosity to medial condyle of tibia
- 50% width of isthmus (smaller than usually recommended as needs to bend with s-shaped bone)
- 30-40% if using with a plate
What unique consideration needs to be realised when placing cerclage around the distal tibia?
The tibia and fibula are closely associated from mid-diaphysis distally usually requiring the cerclage wire to be placed around both bones
External Skeletal Fixation
- minimal soft tissue interference.
- advantage: employ the biologic osteosynthesis (fracture closed or with a very limited open approach)
- Early dynamization to reduce the rigidity of the fixation
- type Ia with an intramedullary pin to improve stability
- Bilateral uniplanar (type II)
Intramedullary Pin Fixation
- limited to stable fractures in small dogs and cats with good healing potential
- Closed normograde pinning
Interlocking Nail
- counteract shear, rotational, and compressive forces
- angle-stable system enables an adequate postoperative mechanical environment even in unstable tibial fractures
- minimally invasive
Plates
- easy approach to the tension band side of the bone
- medial surface of the tibia.
- careful isolation and retraction of the cranial branch of the lateral saphenous artery and vein
- Contouring of the plate (if a nonlocking plate
- plate with screws
- plate-rod combination for nonreducible comminuted fractures
- Minimally invasive plating with locking plate (may not offer superior healing time)
What is the reported rate of non-union in tibial fracture repairs?
4.1%
immature tibial fracture
Incomplete Fractures or Simple Fractures With Intact Fibula
- < 6 months old) and can be treated conservatively with external coaptation such as a lateral splint
Simple (Transverse/Oblique/Spiral) Fractures
- External coaptation in minimally displaced
- short healing time ~ 4 weeks
- reserved for fractures at or below the mid-diaphyseal tibia (difficult to achieve stability of proximal tibial fragment)
- intramedullary pin, a bone plate, or a type Ia external skeletal fixator often indicated
- avoid placing implants in physis
Mature Animals
Simple (Transverse and Short Oblique) Fractures
- load sharing between bone and implants expected; however, necessary to provide rotational stability (i.e not cast/splint)
- compression plate, ESF (Ia, II) or ILN
Long Oblique/Spiral and Reducible Comminuted Fractures
- no splints (not counteract Shear and rotational instability)
- pin along with auxiliary fixation (cerclage wires or screws in lag fashion) in younger
- Neutralization plating with lag screws
- type Ib or II ESF or ILN
Nonreducible Comminuted Fractures
- aim restore the functional alignment
- load sharing by the bone is not expected
- biologic approach
- Types II, Ib, and III and circular or hybrid
- bridging plate: problem when the nonreducible fragments are on the lateral cortex > Repetitive bending stresses
- plate-rod
- bone graft can be applied to the fracture site if an open approach is used
Fractures of the Distal Region of the Tibia
- physeal fractures in young animals and malleolar fractures in mature
- ## 30% to 40% distal region are open
approach to distal tibia
Immature Animals
Fractures of the Physis
- Salter-Harris type I or type II
- closed reduction sometimes possible
- reduced by gently levering the epiphysis onto the metaphysis
- cross-pinning is often the only practical method
- TA pin ONLY if not enough bone for cross pinning
- avoid entering the joint, because the malleoli extend distal to the articular surface
- clinical union usually within 4 to 6 weeks.
What are the repair options of malleolar fractures?
Pins alone
Pin and tension band
Screw
- associated with tarsocrural instability, (subluxation or luxation)
- If joint instability persists, the integrity of the ligaments should be further evaluated
- prognosis generally good; however, degenerative joint disease may develop.
Fractures of the Distal Metaphysis
- distal segment is very short
- many of these fractures are open fractures
- T-plate,
- two locking screws in the distal segment may be enough
- Circular (ring) or hybrid external skeletal fixators
- TA ESF
- no hope of preserving a functional joint, arthrodesis
Complications
- proximal metaphysis is a common location for primary bone neoplasia
- infection,
- implant failure (
- delayed union, nonunion, and malunion (usually inappropriate fixation)
STUDY: Closed reduction and type II, clinical union was approximately 3 to 4 months
- 14% of the dogs had major complications
Tibial Deformity
Premature closure of the tibial tuberosity
- distal drift, increased tension on the patellar ligament > baja and fracture
Premature closure of the caudal proximal growth plate
- increase in the tibial plateau angle > altered stifle mechanics
List the main forms of congenital/developmental tibial deformities and the breeds most commonly associated with them
thought to arise from premature closure of a growth plate
Pes Varus - Dachshunds
Pes Valgus - Shelties, Large breeds
Significant increase in TPA - Westies
Tx: corrective osteotomy and realignment of the limb
Pes Varus and Pes Valgus
- Varus: eccentric medial closure of the distal tibial physis, limg shortening
- Tx: open wedge corrective osteotomy with ESF, hybrid, plate, and plate-rod
- valgus is thought to result from abnormal growth of the distal fibular physis
- both may be associated with MPL
Tibial tuberosity avulsion:
Welsh 2023 – two-pin constructs → higher strength and stiffness vs single pin in load-to-failure
Arun 2022 – non-elective explant after tibial tuberosity avulsion
- 20/64 explanted: 11/20 implant migration, 9/20 seroma, 9/20 patellar desmitis
- risk factors: neutered status → 19x risk; pin size: 0.25mm increase → 2.5x risk
von Pfeil 2021 – fluoro-guided tibial apophyseal percutaneous pinning
- pin type: smooth pins → higher rate of seroma and patellar desmitis → explant 5/19
- vs 0/6 negative-threaded pins
- diverging pins → lower rate of desmitis
- excellent long-term outcome, reduced TPA at follow-up (25.6° → 18.8°)
Tibial Apophyseal Percutaneous Pinning in Skeletally Immature Dogs: 25 Cases (2016–2019)
von Pfeil 2021
retrospective case series
6.2 months, 9.6 kg and 21 minutes
No major complications occurred among the 19 Smooth Pin and 6 Negative TP
Seromas and patellar desmitis
Explantation was needed in 5/19
(TPA) changed significantly between initial (25.6 degrees) and follow-up (18.8 degrees)
excellent in all cases
Based on the amount of
tibial tuberosity displacement, tibial tuberosity avulsion
fractures have been classified as types I to III.
in our opinion, pin-andtension-
band are recommended over tibial apophyseal percutaneous
pinning for extremely active, obese, or large dogs,
bilateral
Recently, a 50% explantation
incidence with tibial apophyseal percutaneous
pinning, versus 0% with pin-and-tension-bands, was stated
increased degrees of pin divergence
increase tibial tuberosity stability
existing presurgical or iatrogenic damage to
the cranial aspect of the proximal tibial physis
consdier implant removal: 5-month-old giant-breed), a negative tibial plateau
angle might develop, possibly fraying caudal cruciate ligament fibres, altering stifle biomechanics and the anatomy of
the tibial tuberosity,
Management of feline tibial
diaphyseal fractures using
orthogonal plates performed
via minimally invasive plate
osteosynthesis
Craig 2018
eight
One major complication
medial plate has a high P:B length ratio, and that the distal screw is placed as close to the talocrural joint as possible, in order to mitigate the risk of iatrogenic fracture of the tibia
plates are placed orthogonally, each plate will
be effectively edge-loaded, increasing the implant’s
area moment of inertia, which increases the resistance
to bending.
Increasing WL has been described to
result in greater elasticity, which allows micro-motion at
the fracture, potentially encouraging rapid formation of
periosteal callus.24,43–45 A higher WL also lowers the pullout
forces exerted on the screws.
when nonlocking
plates are used and the plates were contoured
accurately to the bone, the WL was the length of the fracture
itself
Biomechanical Comparison of Three Stabilization
Methods for Tibial Tuberosity Fractures in Dogs: A Cadaveric Study
Verpaalen 2021
hybrid ESF vs Kirschner wires alonevs with pin and tension band wire
no significant difference in stiffness and load at 3mmdisplacement between PTBW
and HESF fixation
HESF may provide a favourable alternative to PTBW in dogs with substantial remaining growth potential.
tensile load exerted by the quadriceps
muscles in a 25 kg dog at a walk is estimated to be 240N.19
clinical union
defined as presence of a bridging callus or a callus >50% of the tibial diameter at the level of the fracture site on 3/4 cortices on
two orthogonal views
load at failure for PTBW fixations was 1.8 times
greater than the loads sustained by tuberosities stabilized
with Kirschner wires alone.
use of Kirschner wires alone was associated with an overall complication rate of 50%, with 25% of those
complications considered major and necessitating implant
removal
Biomechanical comparison of one pin versus two
pin fixation in a canine tibial tuberosity avulsion
fracture model
Welsh 2022
one larger or two smaller diameter pins
Paired ex vivo biomechanical study
vertically aligned two-pin
fixation offers greater strength and stiffness when compared to a single-pin
fixation.
two-pin fixation would provide rotational stability
cyclic loading to better replicate
recommended insertion angle and pin diameter not known
Linear external skeletal fixation applied in minimally
invasive fashion for stabilization of nonarticular tibial
fractures in dogs and cats
Sherman 2023
Retrospective study.
Animals: Forty-nine dogs and 6 cats.
fluoro used in (72%)
40% complications occurred.
Of these, 18 were considered minor and 4 were considered major
18% pin loosening
open fracture more liekly to have mj complication
All fractures reached radiographic union
Closed application of linear ESF should be considered
A lower than normal TPA
use of intraoperative imaging had no effect on measures of fracture alignment
minor complications were associated
with pin-tract morbidity
with the lateral aspect of the proximal full pin in type II constructs
failure of ESF (n = 1), osteomyelitis requiring
revision (n = 1), sequestrum (n = 1), and refracture post fixator removal (n = 1).
Cabassu30 also reported
acceptable postoperative alignment with minimally invasive
plate osteosynthesis using fracture reduction under
the plate without intraoperative imaging; however, 12%
of cases required immediate revision surgery.
Good clinical outcomes achieved in young dogs with tibial tuberosity avulsion fracture repairs when implants were left in situ past skeletal maturity
Miller 2022
retrospective study, 47 dogs
14% minor long-term complications (stiffness and lameness),
6% major short-term complications (repair failure),
14% major long-term complications (implant removal)
no difference in long-term outcomes in which implants were removed 4 to 6 weeks postoperatively.
42% (3/7) to 90% (36/40) of dogs show bony bridging of the apophysis by 4 to 6 weeks after surgery.1,2 As far as the authors are aware there are no reports of this distalization being linked to clinically important outcomes and 2 studies specifically note no clinically important sequelae
no long term rads,,,
Influence of Kirschner-Wire Insertion Angle on Construct Biomechanics following Tibial
Tuberosity Osteotomy Fixation in Dogs
Hawbecker 2023
either transversely (0 degrees) or
placed caudodistally (30 degrees) with respect to the tibial tuberosity osteotomy
monotonic failure
significantly greater
for Kirschner wires inserted at an angle of 0 degrees compared with 30 degrees.
Construct stiffness did not differ
Kirschner wires
placed at 0 degrees conferring increased resistance of the repair to construct
deformation
61% of dogs presenting for medial patellar
luxation were considered small breeds weighing
<14 kg.
only evaluated two
methods of Kirschner wire orientation,
The effects of tibial tuberosity avulsion and repair on tibial plateau angle in dogs
S Park (goggin) 2024
NZVJ
unilateral surgery when 4–8 months
skeletally mature dogs without stifle pathology were recruited prior to the main study (SD of the differences between
left and right stifles was 2.1°)
In 8/10 of these dogs, the TPA in the
operated stifle was less than in the non-operated stifle. The mean TPA on the operated stifle was 6.4° less than on the non-operated stifle
TPA at maturity increased by 2.7° (95% CI = 1.1–4.3°; p =
0.001) for each additional month of age at surgery.
However, causality cannot be established from this cross-sectional study, and this
association may be because stifles with a smaller TPA are predisposed to tibial tuberosity avulsion.
surgical proximal tibial epiphysiodesis at the age of 8
months, they would expect the mature age TPA to be
between 72.5% and 75% of the original TPA
Ex vivo biomechanical evaluation of 2.4 mm LCP plate rod
constructs versus 2.7 mm LCP applied to the feline tibia
Gutbrod 2024
Ex vivo study.
Sample population: Thirty-three unpaired tibiae
10 mm
diaphyseal gap. Group 1: 2.4 mm locking compression plate (LCP) and 1.0 mm
intramedullary pin (IMP). Group 2: 2.4 mm LCP and 1.6 mm IMP. Group 3:
2.7 mm LCP.
Constructs with a 2.4 mm LCP and 1.6 mm IMP provided the strongest and most rigid constructs in a feline tibia gap model (stiffness and maximum axial force)
Prospective evaluation of the surgical stabilization and
outcome of canine tibial plateau fractures in three cases
Adams 2024
lateral meniscus was elevated to allow visualization
2.0 mm lag screws with washers and two 0.9 mm Kirschner wires (K-wires)
3.no major complications noted. One minor complication
occurred (screw yield two weeks postoperatively). By 8 weeks, all patients reached clinical union with good limb function
one case conccurent CCL avulsion
all vehicle truama, all had concurrent injuries
In human
mechanical studies using a lateral TPF model, articular
steps greater than 1.5 mm resulted in supraphysiological
articular pressures on the proud side of the step-off.17
Efficacy of virtual surgical planning and a
three-dimensional-printed, patient-specific reduction
system to facilitate alignment of diaphyseal tibial fractures
stabilized by minimally invasive plate osteosynthesis in
dogs: A prospective clinical study
Scheuermann 2024
would need to compare to control grooup, ned to assess outcome
Prospective clinical trial.
Sample population: Fifteen client owned dogs
Guides were 3D printed, sterilized, and applied, in conjunction with transient
application of a circular fixator
50.7 h elapsed between presentation and surgery
Virtual planning and fabrication of a 3D-printing
patient-specific fracture reduction system is practical and facilitated acceptable,
if not near-anatomic, fracture alignment during MIPO.
Change in tibial torsion resulted in an increase in external
tibial torsion in 14 dogs.
near-anatomic in 87% of cases and
acceptable in 13% of cases.
Surgical correction of pes varus deformity in dachshunds using three-dimensional-printed patient-specific guide system: nine tibiae in seven cases (2018-2022)
Oxley 2024
retrospectively report the clinical and radiographic outcome.
9 limbs
gait abnormality resolved in all limbs. The osteotomy healed uneventfully in eight tibiae. Implant failure occurred in one
mean translational error <1 mm in all planes, and mean angulation correction error <2° in all planes.
Opening osteotomy, stabilised with orthogonal locking plates and without the application of bone graft
technique complicated by the small distal segment
and the risk of screw violation of the tarsocrural joint.
without fibular osteotomy or fracture, under-correction
is likely
(Petazzoni et al.,
Additionally, torsional correction
will be hampered.
this study not based on CORA (which is 2D planning, not as accuarte, not assess for torsion)
75% cortical bone healing was noted by 6 to 8 weeks
post-operatively
and marked osseous infilling was present. In
four cases imaged over 10 weeks post-operatively
Placement of beta-tricalcium
phosphate (Izumisawa et al., 2005)
and autogenous cancellous bone graft or hydroxyapatite synthetic
bone graft substitute (Chau & Wilson, 2022
Feline Distal Tibial Physeal Fracture Repair Using
a Modified Cross-Pin Technique with Four Pins
Miraldo 2020
modified cross-pin technique for feline distal tibial physeal fracture
- addition of second medial and a craniolateral K-wire to traditional cross-pin
→ additional rotational stability to remove need for coaptation
- pin entry: 1x lateral malleolus, 2x medial malleolus, 1x craniolateral aspect of distal tibia
