Chapter 93 - part 2 diaphyseal fractures Flashcards

Question

how do you immobilize diaphyseal fracture of MCIII MTIII?

Answer 1

The fractured MC/MT3 can be stabilized with a **Robert Jones bandage **and the application of **rigid splints** on the** lateral and palmar/plantar aspects **of the limb. Two splints at **90° angles are necessary to counteract both dorsopalmar/plantar and lateromedial bending** forces.** Polyvinylchloride (PVC) pipe is an effective**, inexpensive splint material; it is light‐weight, strong, and can be penetrated by X‐rays. Splints on the forelimb should extend from the** ground to the elbow.** On the hindlimb, due to the natural bend of the tarsus, the plantar splint can only extend from the g**round to the level of the point of the hock**. The **lateral splint should extend proximally to the level of the stifle joint. **This lateral splint can be made from strong aluminum rod that can be conformed to the angle of the hock and secured to the tibia proximally and to the limb distal to the hock. Splints should be **secured to the limb with nonelastic tape** to avoid loosening. Appropriate splinting is vital to successful fracture treatment. Splinting of the fracture protects the limb from further trauma and minimizes the chance that a closed fracture will become open.

Answer 2

The **joint above and below** the fracture should always be included to evaluate the integrity of the articular surfaces. A **minimum of four views** should be obtained: lateromedial, dorsopalmar/ plantar, and both oblique projections.

Answer 3

Figure 24.4 (Continued). (E) The first plate is applied to the dorsal surface in neutralization or limited compression; (F) A plate screw can also be inserted across a fracture line using lag technique to further secure the butterfly fragment; (G) A second plate is applied laterally or medially, directly over the butterfly, remaining screws inserted in the dorsal plate, and tendons apposed.

Answer 4

Distal physeal fractures in foals most communally have a type II configuration with a variable length of the meta or diaphyseal spike

Answer 5

The nutrient foramen is usually located in the **proximal palmar/plantar cortex **and should be avoided by screws. The nutrient artery of Mc3, a **branch of the medial palmar metacarpal artery**, is accompanied by a corresponding vein and a branch of the **palmar metacarpal nerve** [2]. Neurovascular supplies to the dorsal periosteal surface of Mc3 are provided by small medial and lateral dorsal metacarpal arteries and the **medial cutaneous antebrachial** and dorsal branch of the** ulnar nerves** [3, 4]. The nutrient artery and satellite vein of Mt3 are from the proximal deep plantar arch, the former arising from the medial plantar and perforating tarsal arteries. The periosteal blood supply of the dorsal Mt3 comes from branches of the** dorsal metatarsal arteries**

Answer 6

adults, simple complete diaphyseal fractures can occur at all levels of Mc3/Mt3 and are usually transverse or slightly oblique (Figure 22.1). Comminuted fractures which are most common in older horses can exhibit all levels of complexity. Some of these have one larger butterfly fragment on either the medial or lateral side

Answer 7

Comminuted fractures which are most common** in older horses** can exhibit all levels of complexity.

Answer 8

YES!! If periosteum lost, more Haversian systems of the cortical exposed →** susceptible to infection**

Answer 9

**Reduction of the fracture** *Reduction (may be difficult) *Comminuted#s reconstruct into 2 pieces *Tent fracture ends out of surgical wound → align and interdigitate or *Traction+ bone reduction forceps *Oncereduced maintain using lag screw (3.5mm)*Contourand apply plate to bone *Ideally 2 broad but dependent on skin closure *4.5/5.5mmscrews? Dynamiccondylar screw (DCS) plate

Answer 10

Autogenous cancellous grafts obtain from TX sternum

Answer 11

*Antibiotic impregnated beads (or other) *Suture tendon (if split)*0or 2-0 PDS II*Continuouspattern *SQtissue *Skin*0or 2-0 prolene *Vertical mattress *RJB or full limb cast *Assisted recovery: -Raft/swimmingpool -RopesHandassisted

Answer 12

*Infection *Osteomyelitis *Nonunion *Sequestrum *Contralaterallimb failure *Laminitis

Answer 13

45-60 days

Answer 14

Suckling and weanling foals

Answer 15

Cast coaptation for 2 to 3 weeks, followed by a splinted bandage

Answer 16

Surgical repair with screws in lag fashion

Answer 17

As early as 3 to 4 weeks

Answer 18

**Proximal articular fractures** have been treated **conservatively **with** good success,** but **displaced frontal plane** fractures are best repaired with** internal fixation** through cortex screws inserted in lag fashion (Figure 93-21). The** sagittal plane fractures** are rarely displaced and usually heal with stall rest alone

Answer 19

**With local anesthetic injected into the middle carpal or tarsometatarsal joint**

Answer 20

90-120 days

Answer 21

Bucked shins

Answer 22

Oblique radiolucent lines in the dorsal cortex

Answer 23

As 3-year-olds

Answer 24

30 to 40 degrees

Answer 25

60% to 70%

Answer 26

Anti-inflammatory agents and rest

Answer 27

Through sequential radiographs

Answer 28

A significant percentage

Answer 29

Distal or proximal metaphyseal regions of MCIII

Answer 30

Providing local analgesia

Answer 31

Avoiding a second operation to remove the screw

Answer 32

Local anesthesia

Answer 33

Because it is often difficult to identify visually during surgery

Answer 34

Because it is easier to remove later

Answer 35

Postoperative care includes stall rest and hand walking for 2 to 4 weeks followed by **4 to 6 weeks of stall rest and paddock exercise**. At **60 days postoperatively, the horse is returned for screw removal**

Answer 36

A4- to 6-cm incision is made over the fracture site. In the typical dorsolateral fracture, the incision is between the common digital and lateral digital extensor tendons. The incision is made boldly directly to the level of the periosteum to minimize dissection. The periosteum is elevated, and self-retaining retractors are placed to expose the bone surface. a position screw (without a glide hole) within the dorsal cortex is usually placed. In the middiaphysis of MCIII, bending occurs, therefore insertion of a screw engaging both cortices is not recommended. Drilling with a small bit in dorsal MCIII must be done with irrigation and frequent cleaning of the bit to avoid breakage or causing thermal injury An oblique drill hole is made into the medullary cavity in what is estimated to be the correct location. Subsequently an intraoperative radiograph is taken (Figure 93-25) and if the hole is correctly positioned, it can be used for the screw. If the trial hole is too proximal or distal, an adjustment is made and the first hole serves as just another osteostixis hole

Answer 37

Although some surgeons use lag technique, typical dorsal cortical metacarpal stress fractures have no displacement and the effect of compression would be trivial. Because compression of the fracture is not necessary for successful treatment,33 a position screw (without a glide hole) within the dorsal cortex is usually placed. Why you don't countersink?

Answer 38

Because you will remove the screw in 60-80 days

Answer 39

Because the screw is not countersunk, it should not be excessively tightened or it will bend. Perhaps the easiest error to make is not tapping completely through the dorsal cortex. The consequence of this is that a 3.5-mm screw will easily break during tightening.

Answer 40

Figure 22.3 (a) Incomplete stress fracture in the dorsolateral Mc3 cortex with a typical dorsodistal to palmaroproximal course (black arrows). (b) Surgical treatment with a unicortical 4.5 mm cortex screw and osteostixis (white arrows).

Answer 41

Figure 22.4 Acute, incomplete longitudinal spiralling fracture of the Mc3 crossing the nutrient foramen and continuing into the carpometacarpal joint (arrows). Multiple radiographs in different projections are necessary to follow the fracture plane.

Answer 42

Figure 22.5 An acute, incomplete, longitudinal fracture of Mc3 (arrows) (a) two days after the injury and (b) 14 days later consistent with osteoclast activity

Answer 43

Figure 22.7 Lateromedial (a) and oblique (b) (a) (b) radiographs of a Thoroughbred racehorse with a transverse stress fracture in the distal metaphysis of Mc3. Note the palmar callus formation and incomplete fractures of palmar (white arrows) and dorsal (black arrows) cortices.

Answer 44

Figure 22.8 Lateromedial radiographs of a transverse fracture of the distal diaphysis of Mc3 in a two-year- old Thoroughbred. (a) Two months after acute onset lameness demonstrating abundant periosteal and endosteal callus and (b) 15 months later. The filly had trained and raced in the interim.

Answer 45

Figure 22.9 Comminuted fracture of the Mc3 in a 200 kg pony. (a) Dorsopalmar and lateromedial radiographs. The fracture was reduced following an open approach with multiple lag screws. A DCP plate was applied dorsally and included engagement of the third carpal bone. A transfixation cast was then applied utilizing metaphyseal and distal diaphyseal pins in the radius. (b) Radiographs taken at the end of surgery before application of the cast.

Answer 46

Figure 22.12 Open, displaced transverse diaphyseal fracture of Mt3 in a foal and repair with LCPs dorsolaterally and dorsomedially.

Answer 47

Figure 22.13 Intra-operative photograph and radiograph of a transverse mid-diaphyseal fracture after reduction and placement of dorsal and lateral LCPs. The fracture is temporarily fixed with a lag screw and both plates are compressed to the bone with cortical screws. Drill guides for LHSs are inserted at the proximal and distal end of the lateral plate to assess the direction of the screws near the joint.

Answer 48

Figure 22.14 (a, b) Oblique fracture in the proximal diaphysis of Mc3 in a three-month- old foal. (c, d) Stable repair with a dorsal 8-hole 4.5/5.0 LCP T-plate and a lateral 10-hole narrow 4.5/5.0 LCP.

Answer 49

Figure 22.15 Minimally invasive repair of an oblique mid-diaphyseal fracture of Mt3 in a neonate. (a) Dorsoplantar and (b) lateromedial radiographs taken in a splinted bandaged on arrival demonstrating valgus displacement and overriding. (c) The foal is positioned in dorsal recumbency with traction applied by an overhead hoist. (d, e) DP radiographs in surgery demonstrating progressive reduction with increasing traction. (f) Haemostats inserted dorsodistally to create a sub tendinous tunnel. The long digital extensor tendon is gripped in the surgeons left hand. (g) Stacked LHS drill guides used to create a handle for insertion of the LCP. (h) LCP location confirmed in a LM radiograph (i) Plate/bone contact created by insertion of 2 × 4.5 mm cortical screws. (j) Construct at the end of surgery with the remaining plate holes filled with 4 mm LHS. (k, l) DP radiographs and (m) clinical appearance 12 days after surgery.

Answer 50

Figure 22.17 Dorsoplantar radiographs of an open, oblique fracture of the mid-diaphysis of Mt3 in an Icelandic horse. (a) At presentation. (b) Repair with dorsal and lateral LCPs. Implants were removed due to chronic low grade lameness. (c) The dorsal implant was removed one year after repair and the lateral plate six months later. Lameness resolved after implant removal. (d) 3.5 years after fracture repair.

Answer 51

Figure 24.12 Radiographs showing a longitudinal palmar fracture (arrows) of the third metacarpus in a two‐year‐old Thoroughbred. Lameness had been intermittently severe and was unresolved after two months of stall confinement. (A) Dorsopalmar radiograph and (B) standing robotic computed tomographic image confirm the palmar location and length of the fracture. (C, D) Dorsopalmar and lateromedial radiographs two days after insertion of two 4.5 mm screws in the palmar cortex. (E) Dorsopalmar radiograph 60 days after repair showing resolution of the fracture. The horse returned to training 90 days after surgery.

Answer 52

Figure 25.3 Radiographic appearance of dorsal cortical fractures. (A) Dorsodistal angled focal cortical stress fracture of the third metacarpus. (B) Saucer fracture, with extensive periosteal reaction, proximal (arrow) and distal aspects (arrowheads) of the saucer fracture.

Answer 53

Figure 25.9 Preparation for standing dorsal cortical fracture repair with cortical screw insertion and limited osteostixis. Plastic adhesive drapes are applied and proximal and distal hand towels are secured with sterile VetrapTM (3M Healthcare). A sterile glove over the foot can substitute for the distal hand towel.

Answer 54

Figure 93-20. Although many methods can be successful for treatment of distal Salter-Harris type II MC/MTIII fractures, a very reliable technique is to combine simple lag technique of the metaphyseal spike with a screw and wire transphyseal bridge.

Answer 55

Figure 93-21. Displaced dorsal plane proximal MTIII fracture treated with a cortex screw placed in lag fashion. This horse won multiple graded stakes races after surgery.

Answer 56

Figure 93-22. Proximal sagittal plane fracture of MCIII (arrows), which was treated conservatively.

Answer 57

Figure 93-26. When drilling dorsal cortical stress fractures, it is important to aim toward the medullary cavity.

Answer 58

Figure 93-23. (A) The most common configuration of dorsal cortical stress fractures of MCIII is shown with the arrow. Less distinct lucencies (arrowheads) can be seen separately or in combination with larger fractures. (B) Occasionally, the opposite (“upside down”) configuration is seen. The quality of digital imaging has made identification of these fractures more reliable.

Answer 59

Figure 93-18. (A) A dorsopalmar radiograph of a nondisplaced transverse fracture of the distal diaphysis showing periosteal callus. (B) A dorsopalmar radiograph of a displaced, comminuted transverse fracture. This fracture was successfully treated with arthrodesis of the metacarpophalangeal joint as seen in C and D. A variable angle-LCP curved condylar plate may also be useful for stabilization of distal diaphyseal fractures in horses where return to athleticism is of utmost importance. A postoperative dorsopalmar (E) and lateromedial (F) radiograph of a transverse fracture repaired with a variable-angle-LCP curved condylar plate.