Ch 63 Tibia fracture Flashcards

Question

Fractures of the Physis

Answer 1

- Salter-Harris type I or II - combined proximal epiphysis and tibial tuberosity are usually involved - may be accompanied by collateral ligament damage

Answer 2

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.

Answer 3

- 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

Answer 4

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

Answer 5

- account for 70% to 80% of all fractures of the tibia. - Oblique and spiral fractures are the most common

Answer 6

- 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

Answer 7

The tibia and fibula are closely associated from mid-diaphysis distally usually requiring the cerclage wire to be placed around both bones

Answer 8

- 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)

Answer 9

- limited to stable fractures in small dogs and cats with good healing potential - Closed normograde pinning

Answer 10

- counteract shear, rotational, and compressive forces - angle-stable system enables an adequate postoperative mechanical environment even in unstable tibial fractures - minimally invasive

Answer 11

- 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)

Answer 12

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

Answer 13

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

Answer 14

- physeal fractures in young animals and malleolar fractures in mature - 30% to 40% distal region are open -

Answer 15

- 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.

Answer 16

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.

Answer 17

- 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

Answer 18

- 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

Answer 19

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

Answer 20

Pes Varus - Dachshunds Pes Valgus - Shelties, Large breeds Significant increase in TPA - Westies Tx: corrective osteotomy and realignment of the limb

Answer 21

- 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

Answer 22

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°)

Answer 23

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,

Answer 24

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

Answer 25

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

Answer 26

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

Answer 27

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.

Answer 28

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,,,

Answer 29

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,

Answer 30

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

Answer 31

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)

Answer 32

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

Answer 33

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.

Answer 34

Retrospectively. 9. pes varus deformity in dachshunds using three-dimensional-printed patient-specific guide system gait abnormality resolved in all limbs. The osteotomy healed uneventfully in eight tibiae. Implant failure occurred in one mean translational error <1 mm , angulation error <2° Opening osteotomy, stabilised with orthogonal locking plates and without the application of bone graft without fibular osteotomy or fracture, under-correction is likely (Petazzoni et al., not based on CORA (which is 2D planning, not as accuarte, not assess for torsion) autogenous cancellous bone graft or hydroxyapatite synthetic bone graft substitute (Chau & Wilson, 2022 > correction with mini-hybrid ESF medial opening wedge, All osteotomies healed and fixators were removed between 6 and 12 weeks. Lameness resolved in 18 dachshunds (90%), all lateral MPL resolved)

Answer 35

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

Ch 63 Tibia fracture Flashcards

(64 cards)