Chapter 82 - Arthrodesis tx Flashcards

Question

Why do you palce a staggered monocortical 4.5 mm cortex screw in the proximal end of the plate?

Answer 1

The rationale for inserting the most proximal screw monocortically is to stagger the stress riser that might arise at the proximal end of the plate between the dorsal and palmar/plantar cortices of the proximal phalanx.

Answer 2

eminence fracture first reduced with lag screw get the distal end in P2 once in place Place cortex screw in load position on the proximal plate (pink) monocortical abaxial transarticular scrws Slight degree of flexion in the joint and when Tight P1 load screw (pink)** increases the compression in the joint itself** Place the other lock screws

Answer 3

In heavy Warmblood horses additional stability may be achieved by using two additional 5.5-mm screws inserted in lag fashion across the joint

Answer 4

Closure of the V-plasty of the tendon is accomplished with size USP 1 polydioxanone suture simple continuous skin is apposed using a combination of size USP 0 polypropylene Skin staples Standard distal limb cast that is removed in 2 weeks and after Robert Jones half-limb bnadage Discharg 3 weeks postop 6 weeks hand grazing Progressive hand walking on second 6 weeks First radio control at 3 months postop

Answer 5

b)disruption of the palmar/plantar support structures of the PIP joint The eminences have to be stabilized lag screw axially (plates abaxial)

Answer 6

You place the** screws AXIAL** in the **fragments in lag fashion** the rest is the same with** 2 plates ABAXIAL** Place the **screw proximal to P2 with LHS** followed by proximal screws in the plates and you finish your fixation with LHS in the rest of the scrws

Answer 7

Horses with fairly advanced OA with significant cartilage loss *Lateromedialand dorsopalmar/-plantar burr with a 5.5-mm drill for adequate cartilage destruction *The two 5.5-mm transarticularscrews are first placed *LCP placed with device through small dorsal stab incisions through the tendon *It has been reported that osseous fusion of the joint with this type of arthrodesis progresses more slowly than that seen with the traditional open technique *Lameness remains for several weeks, requiring castcoaptation for more than 6 weeks.

Answer 8

*implants for surgical arthrodesis is not recommended in the acute stage because of increased risk of a generalized infection of the implants. Immobilize with cast or transfixation cast with agressive debridement of the joint cancellous bone graft AB sytemic and local

Answer 9

*87% returned to intended use with asuccess rate of 81% for forelimb arthrodesis and 95% for hindlimb

Answer 10

1. short incomplete 2. long incomplete 3. complete uniarticular 4. complete biarticular 5. dorsal complete biarticular 6. palmar/plantar eminence 7. multrifragmentary 8. transverse body

Answer 11

Arthroscopy Extenson of the MCP joint and distend with fluid 35 mL The site for the laterally placed arthroscopic portal is in theproximolateral quadrant created by distending the joint maximally, lateral to the common digital extensor tendon

Answer 12

WHERE? sagittal plane ORIGINATED? in the articular surface of the sagittal groove of P1 CENTERED dorsally but not usually bicortical Many tx conservativly box 2 months and 1 month handwalking SURGERY reserved for the ones that do not healafter 3 months of conservative

Answer 13

FL 94% HL 88% Insert 3.5 mm or 4.5 mm cortical screws in lag technique in triangular screw configuration Distal to lateral colateral ligament FIRST INCISION is proximal to extensor branch of extensor suspensory ligament SECOND just distal to theextensor branch THIRD in the distal end of the fragment Because of the special cross sectional shape of the boné theproximal screwshould not be exactly inserted in the center of the bone as viewed from aside Such location would result in excessive compression of the palmar córtex andcouldopen the dorsal córtex. Therefore the ideal screwplacement is placement slightly dorsal as shown on the redline.

Answer 14

10 hole to 14 hole broadlockingcompressionplate 5.5 mm cortex screws 5.0 mm lockingscrews 1.7 mm cable Large wire passer

Answer 15

1. OA 2. Severe comminuted complex proximal sesamoid bones 3. any major lesion of the suspensory apparatus

Answer 16

Incision over the lateral digital extensor tendon from proximal MC to mid pastern Elevate all soft tissues as envelpe (extensor tendon, periosteum, joint capsule, collaterals) Preparation ofjoint surface with curette and multiple osteostixis holes drilled across SCbone with 1 mm deep with 3.2 mm drill

Answer 17

4-mm hole is drilled from lateral to medial atphyseal scar level of MCIII/MTIII and the proximal phalanx, respectively. Pass the cable 1.7 mm or cerclage 1.25 mm diameter and make a figure 8 with wire or cable passeracross the palmar/plantar aspect of the joint. Test the angle you want the fetlock to be 10 -15º once you pass the cable through the crimp the cable Secure the crimping tool and cut the cable off

Answer 18

Drill 5.5 mm glide holes for transarticular screws before placing the plate on to see the a Angle one 5.5-mm cortex screw is placed in lag fashion from the dorsal aspect of the distal MCIII or MTIII into each proximal sesamoid bone. 10-14 hole broad 5.5 mm LCP plate is slight bent between 4th and 5th holes about 10 degrees Align the plate to dorsal surface of P1 and MCIII 1 cortex screw is inserted through the DCU-portion of the combi hole next to the stacked comi-hole and solidly tightened 5.5 mm cortex screw The two adjacent plate holes (distal in P1) are filled with LHS and attach the plate firmly onto the proximal phalanx Place a plate tension device in the proximal hole in the MCIII Start introducing the 5.5 cortex screws to allow the plate to be firmly pressed onto the bone surface in the remaing holes. Be cautious with the tension band otherwise you will have to restart again Place the transarticular screws in the glide holes previously prepared 5.5 mm lag fashion

Answer 19

Figure 82-10. Immediate postoperative lateromedial (A) and dorsopalmar (B) radiographs of a PIP joint arthrodesis in a 3-year-old Warmblood horse with traumatic luxation of the PIP joint. The arthrodesis was accomplished with a three-hole narrow 4.5/5.0-mm PIP arthrodesis LCP and two abaxial 5.5-mm cortex screws. The plate used two 5.0-mm LHS and a single unicortical (unicortical to reduce stress concentration in the middle of the bone) 4.5-mm screw in the proximal hole (inserted under load). The two transarticular 5.5-mm cortex screws were inserted in lag fashion to provide plantar compression. The 2-year follow-up lateromedial (C) and dorsopalmar (D) radiographs show complete fusion of the joint, with negligible periarticular new bone formation. (

Answer 20

Transarticular screws touched the tension band

Answer 21

polymethylacrylate with 5 mL (250mg/ml) amikacine and mix and introduce all over the plate while is liquid next to the plate everywhere but avoid the screw heads.

Answer 22

No, it is strictly for the soft tissue support specially if swollen. Recovery was done with head and tail rope or pool-raft recovery system

Answer 23

195º angle

Answer 24

All horses survived to discharge No complications or infections of implants, only cast sores Good/Excellent long-term outcomes for pasture and breeding soundness in horses with OA

Answer 25

Traumatic disruption of the suspensory apparatus is associated with significant soft tissue trauma, including injury to the vasculature of distal limb and reperfusion injury

Answer 26

5.5 mm cortical screw 4.5 mm drill

Answer 27

68% for MCP joint 59.5% for the two sesamoid bones more cartilage removed LATERAL vs medial

Answer 28

1) Tx of comminuted carpal fractures (salvage for non athletic purpose) 2) Luxations or subluxations

Answer 29

Technique1 -**4.5 drill bit** inserted through **four entry points** and moved in a fanning fashion Technique2 - **5.5 drill** bit inserted thtough** two entry points** to creat drill tracts - More even distribution of art damage than technique 1 Technique3 - **4.5 drill **bit inserted through** two entry points** to create **three drill tracts** - 1and 2 were more effective

Answer 30

Partial carpal arthrodesis: - Distal carpal row is injured and/or one major joint involved OA - Certain amount of flexion is possible Pancarpal arthrodesis: - All 3 joints are fused - No flexion possible

Answer 31

This horse has severe omminuted fracture of C4 and ulnar carpal, intermediate will get a pancarpal arthrodesis

Answer 32

Involves wither fixing the proximal row of carpal bones tothe distal row and MC or fixing the distal row of carpal bones to the MC

Answer 33

Various plates can be used LCP prefered - Choice depends : horse size , availability , surgeonpreference - 68 holes used -Recently 4.5 LCP T place is ideal

Answer 34

- Dorsal or lateral recumbency - Full flexion - Carpus approached through 2 vertical skin and subcutaneous incisions on **either side of the extensor carpi radialis** Incisions extended through the joint capsule of the affected joint -** Art. cartilage should be removed **to facilitate fusion with arthroscopy or blindly - Osteotixis+ cancellous bone graft or alternative osteoinductive material are indicated to enhance fusion - In **comminuted carpal** bone fractures, **interfragmentary screws inserted in lag fashion** across large bony fragments improvestability - Prudent to apply** 2/3 plates across the joints to maintain alignment** - Also for subluxation with avulsion fractures or bone’s displacement

Answer 35

Place the horse in Robert Jones from elbow to the fetlock with lateral and plantar splint

Answer 36

Use of broad DCPs or LCPs for comminuted fractures involving both rows and for degenerative carpal joint disease inolder horses - Purpose of the plates is to stabilize and maintain straigh axis -5.5/5.0 LCP and dynamic hip screw (DHS) or dynamic condylar screw (DCS) are excelent options stronger than DCP -Plate luting recommended whe using DCP

Answer 37

DR - **full flexion for destruction of the cartilage** Place the **leg in extension** with t**raction to reduce the fracture** Incision of **40 cm vertical skin incision** dorsal aspect of the limb **centered over the carpus** Make a **tunnel under tendon** and capsule between **ECR and LDE** Use a **passer and place the plate** in contact with the bone Use **7 to 8 hole broad LCP **that is introduced slightly dorso lat Place drill guides in all holes and start **LATERAL plate** should be placed as lateral as possible **palmarolateral** Place all drill guides at same time and guide with radio your screws positions to place you LHS

Answer 38

Figure 82-19. Lateromedial radiograph depicting pancarpal arthrodesis used to repair a comminuted carpal fracture. A 12-hole broad DCP bone-lengthening plate was applied to the dorsocranial aspect of the limb, and a narrow 12-hole DCP was applied laterally. Cortex screws were used to provide interfragmentary compression across slab fractures.

Answer 39

Figure 82-17. (A) Dorsopalmar, (B) lateromedial, and (C) dorsolateral-palmeromedial radiographs of a second carpal bone fracture in a 2-year-old Warmblood gelding treated by means of partial carpal arthrodesis using two two broad (six- and seven-hole) and one narrow (six-hole) 4.5/5.0-mm LCPs to treat the fracture.

Answer 40

Figure 82-18. (A) Dorsomedial-palmarolateral preoperative radiograph of a multifragment fourth carpal bone fracture in a 7-year-old mare; (B) dorsopalmar radiograph of the partial carpal arthrodesis performed on the horse using two narrow LCPs (six and seven hole) and one LCP T-plate (six hole). (

Answer 41

facilitate skin closure, several towel clamps can be used to fatigue the skin edges. In extreme cases, a relief skin incision is made at a location distant to the main skin incision, avoiding an area where pressure necrosis may develop under the splint or cast

Answer 42

Use a cast for the recovery and after you can place a Robert Jones

Answer 43

Yes using LCP plate fixation tx for partial and pancarpal joint with good success. You have to drill the joint surface through stab incisions

Answer 44

supporting limb lameness, incisional infections, implant infection.

Answer 45

Advance OA persistent luxations or subluxations May treat miniature or small horses breeds to relieve from painfull lameness Notwell suited for horses Thereis one report where it was sucessfull in a paint horse w/2 LCPs

Answer 46

**Lateral recumbency **w/ affected limb up - **Curvilinear incision** through skin and subcutaneous tissue from **midscapula to midhumerous** -Incisionis continued at the - caudal border of the **brachiocephalicus mm** - through the **omotransversus** to expose **biceps tendon** - **supraspinous is transected** at level of inserion on the **GT of humerus** - **suprascapular n. ID** -** biceps tendon transected distal to the supraglenoid tubercle and reflected to expose the shoulder joint. - Joint capsule is incised - curettage - **intermediate tubercle** is** removed** with oscillating saw

Answer 47

- **10 - 12 hole 4.5 DCP or 4.5 LCP** - Contoured to the **cranial surface of the scapula** and humerus ,** angle of 120º** - Plateis compressed using **two 4.5 cortical screws** proximal and distal tothe joint - One or two plate holes located over the joint should be filled withtransarticular screws in lag -There maining holes are filled with locking screws

Answer 48

**Craniocaudal radiographic** view of a S**H joint subluxation** in a Miniature horse stallion. (B) Lateromedial radiographic view of the SH joint arthrodesis performed in this patient. A **16-hole 3.5-mm LCP** was applied to the cranial aspect of the joint region. Over the joint, transarticular screws were implanted through the plate, providing additional stability to the fixation.

Answer 49

- OA of the TMT and DIT unresponsive to medical tx - Ocasional luxation involving TMT or DIT -Talocalcanealarthrodesis has been described as a tx fortalocalcaneal OA

Answer 50

Chemical induced ankylosis Laser-facilitated ankylosis Transarticular drilling technique Fixation techniques using T-plate

Answer 51

*monoiodoacetate (MIA) and ethylalcohol.

Answer 52

100 to 250 mg of MIA,a chemical compound that causes cartilage death and stimulates fusion, wasintroduced as a treatment for osteoarthritis of the TMT and DIT joints

Answer 53

severity of discomfort of the horseimmediately after treatment, postinjection soft tissue swelling, progression ofosteoarthritis in the PIT joints, severe soft tissue necrosis that can occurwith extraarticular injection, variable length of convalescence, andinconsistent outcome

Answer 54

*is through **nonselective protein denaturation** and cell protoplasm precipitation and dehydration *neurolytic agent that results in asensory innervation blockade at the intraarticular level *neurolytic properties andnonselective destruction of proteins contribute to its success at disruptingthe cartilaginous matrix, causing necrosis of the chondrocytes and facilitatingarthrodesis

Answer 55

*LR expose dorsomedial aspect of the tarsus involved. *3-cm vertical skinincision is made on the dorsomedial aspect and centeredover the TMT and DIT joints. *The sites for drill bit entry are midwaybetween a line extending from the groove between the proximal MTII and MTIII,and the most dorsal aspect of the distal tarsus (at the level of the TMT andDIT joints) ID TMT and DIT with needles and intraop radio 4.5 mm drill bit is passed into the joint space in 3 directions from single entry point on the dorsomedial aspect of the tarsus creating a fan-like pattern a 20-mm-long tract is directed toward themost lateral palpable extremity of the MTIV; second, a 20-mm tract angled 30degrees to the first in a plantar direction; third, a 35-mm tract angled 30degrees to the first in a dorsal direction.

Answer 56

penetration of the tarsal canal,resulting in unnecessary periosteal reaction or profuse hemorrhage fromdisruption cranial tibial artery

Answer 57

4.5/5.0-mm LCP T-plate over thedorsomedial aspect of the tarsal region 3-cm longitudinal skin incision ismade at the dorsomedial aspect of the distal tarsal join(adjacent to plantar margin of saphenous vein) medial branch of the tibialis cranialismuscle is then dissected to expose the TMT and the DIT joint Drill of cartilage of TMT and DIT Fill the holes with bone graft plug harvested from the proximal tibia or the tuber coxae Four hole 4.5/5.5 mm LCP T-plate is applied dorsomed through skin incision - minimal contour screws in the MTIII are inserted through stab incisions intraop imaging in multiple directions is important for adequate placement of 4.5/5.5 mm LCP T plate Insert 5.5 mm cortex screw into the central tarsal bone to compress the plate firmly onto bone Second cortex screw in load position is place through the most distal stacked combi-hole in the plate into MTIII Remaining plate holes are filled with LHs

Answer 58

*Postoperatively, the limb is keptunder a bandage for 2 to 3 weeks. *Lameness can persist for severalmonths *Rehabilitation must be conductedgradually over several months.

Answer 59

Plantarolateral plate application

Answer 60

*skin incision extends from the topof the calcaneus to the mid-MTIII on the plantarolateralaspect. *subcutaneous tissues are separatedto expose the bone and the luxated joint Asmuch cartilage as possible is removed from the affected joint using a curette

Answer 61

Cartilage removed from affected joint Then the luxation is reduced andthe head of the MTIV is trimmed with a chise OR alternative approach involvesremoving the entire MTIV. *appropriate plate spans the area ofinstability and extends from the proximal calcaneus to the midmetatarsalregion *Depending on the size of the horse, thisis typically a 9- to 16-hole broad DCP or LCP plate*contoured to the bones *plate is fixed with two corticalscrews using the dynamic properties of the plate to compress the area ofinstability *At this stage, the unaffecteddistal tarsal joints are drilled focally (as described earlier) to encourage transarticularnew bone formation *remaining screw holes are filledwith 5.5-mm cortex screws or LHSs respectively *Solid purchase of each screw in healthybone and engaging both corticals isof great importance with this fixation. *If possible, several oblique transarticularscrews are inserted across the luxated joint to provide additional stabilityand support across the major portion of affected joint *In locations that requiresubstantial screw angulation through the plate, 4.5-mm screws may be used. *For luxationsof the distal tarsal joints with dorsomedial instability, a 4.5/5.0-mm LCPT-plate is applied to the medial or dorsomedial aspect of the distal tarsus

Answer 62

FULL LIMB cast applied for 2 weeks period and after Robert Jones for 2-3 additional weeks

Answer 63

Handwalk 2 months Light work 3 months

Answer 64

(A) Craniocaudal radiographic view of a TMT luxation in a pony. (B) Oblique postoperative radiographic view of the tarsal region after application of a nine-hole narrow 4.5/5.0-mm LCP to the plantarolateral aspect of the calcaneus and proximal MTIII region.

Answer 65

Figure 82-22. Graphic illustration of the drilling technique for tarsal arthrodesis. The sites for drill bit entry are midway between a line extending from the groove between the proximal MTII and MTIII, and the most dorsal aspect of the distal tarsus (at the level of the TMT joint and DIT joint). Three diverging drill holes are made along the articular surfaces of the distal tarsal joints using intraoperative imaging.

Answer 66

Figure 82-23. Graphic illustration of a tarsal arthrodesis with a four-hole 4.5/5.0-mm LCP T-plate applied dorsomedially.

Answer 67

Figure 82-24. Minimally invasive approach for placement of a 4.5/5.0-mm four-hole LCP T-plate. Intraoperative regional perfusion of antimicrobials can be performed in an attempt to reduce the risk for postoperative infection in distal tarsal joint arthrodesis.

Answer 68

Figure 82-25. Intraoperative imaging is important for optimal placement of a four-hole 4.5/5.0-mm LCP T-plate to the dorsomedial aspect of the DIT joints. The plate is contoured to the bone to facilitate skin closure. (A) DLPMO view shows the contouring of the plate and the position of the screw holes; (B) DMPLO view is required to adjust the position of the T-bar in relation to the joint space of the PIT joint.

Answer 69

Figure 82-27. (A) Lateromedial, (B) dorsomedial- plantarolateral, (C) dorsolateral-plantaromedial, and (D) dorsoplantar radiographs of an arthrodesis of the distal tarsal joints using a four-hole 4.5/5.0-mm LCP T-plate in a 7-year-old Warmblood mare with chronic lameness because of severe osteoarthritis.

Answer 70

Figure 82-26. (A) Intraoperative DLPMO view of the 4.5/5.0-mm LCP T-plate at the dorsomedial aspect of the distal tarsal joints. Tension across the DIT joints and the TMT joint is achieved by inserting a second cortex screw in loading position in the MTIII. (B) A cortex screw is being inserted across the DIT joints to counteract rotational forces.

Answer 71

Figure 82-28. (A) Intraoperative DMPLO radiographic view of a 560-kg Warmblood stallion with a plantar instability in the DIT joint. A 12-hole broad DCP is contoured to the bone and two 4.5-mm cortex screws are applied using the dynamic compression properties of the plate to compress the DIT joint. (B) Stable fixation is achieved using six screws proximal and six screws distal to the subluxated DIT joint. The horse made an uneventful recovery and could be used as a breeding stallion.

Answer 72

Figure 82-29. (A) Craniocaudal radiographic view of a TMT luxation in a pony. (B) Oblique postoperative radiographic view of the tarsal region after application of a nine-hole narrow 4.5/5.0-mm LCP to the plantarolateral aspect of the calcaneus and proximal MTIII region.

Answer 73

Figure 82-30. Oblique postoperative radiographic view of a talocalcaneal arthrodesis performed through three converging 5.5-mm cortex screws inserted in lag fashion across the lateral facet of the talocalcaneal joint. Washers were used in the two proximal screws to increase the contact area of the implants and reduce stress concentration at the bone–screw head junction.

Answer 74

LR with affected limb uppermost

Answer 75

***lateral aspect of the calcaneus** aslightly **curved incisio**n is made from the m**idpoint of the bone to its distal end** *tissues are sharply divided down tothe bone. ** *Needle markers** are used to determine the **correct angulation **of the future screws under **fluoroscopic guidance** ***drill bit** is** aimed** toward the **plantaromedial **aspect of the **medial trochlear** **ridge of the talus**, avoiding penetration of the **tarsocrural joint** at the **intertrochlear groove.** ***Two or three 5.5-mm cortex screws** areinserted in** lag fashion** across the lateral facet using routine technique

Answer 76

Complications of arthrodesis include: postoperative infection, implantfailure, laminitis in the opposite limb, long-term lameness, development ofangular limb deformities *Accidental insertion of bone screwsinto a joint space can provide a continuous source of pain and should beavoided