Arthrodesis of PIJ / Bone Spavin Flashcards
Indications for Pastern Arthrodesis:
1.
2.
3.
4.
- High Ring Bone
- Pastern Luxation
- Fracture of P2
- Septic arthritis of Pastern
What is High Ringbone?
Low ringbone?
Osteoarthritis/osteophytes of proximal pastern joint (PIP)
OA/osteophytes of coffin joint
T/F:
Natural ankylosis as healing for OA of PIP joint is unlikely
T
2 Main Goals of PIP arthrodesis
1.
2.
- Removal of all articular cartilage
2. Maintenance of rigid stability of the joint
3 main surgical techniques for pastern arthrodesis
1
2.
3.
- Trans-articular lag screws
- Dorsal plate (DCP or LCP)
- Both! This is the best way to do it
Benefits of TA screws + Dorsal Plate as tx choice for Pastern Arthrodesis:
1. 2. 3. 4. 5. 6.
- Enhanced stability
- Improved comfort post-op
- Shorter time in a cast
- Shorter return to function
- Shorter hospitalization time
- Less peri-articular new bone formation on dorsal aspect
Surgical Technique for TA Screws + Dorsal Plate Arthrodesis:
- _______ incision
- Dissect through SQ to the _____-
- Elevate and retract…..
- Transect ____ with ___ incision
- Remove….
- Inverted T incision
- CDE tendon
- 2 skin triangles
- CDE inverted V
- bony proliferation
Surgical Technique for TA Screws + Dorsal Plate Arthrodesis:
You’ve already made the incision and remove bony proliferation. Next steps:
- Transect ___, ____, ___-
- Remove _____
- Osteostixis of ______
- Drill bit?
- joint capsule, MCL, and LCL.
- Cartilage
- subchondral bone plates (P1 and P2)
- 2.5 mm
Drilling during Surgical Technique for TA Screws + Dorsal Plate Arthrodesis:
- Drill through what?
- Purpose of drilling?
- through subchondral bone plate into medullary canal
2. Promote bone healing by bringing in bone factors and mesenchymal cells.
Surgical Technique for TA Screws + Dorsal Plate Arthrodesis:
- (extend/flex) foot?
- ___-hole plate on dorsal surface (axially/abaxially)?
- use ____ plate
- How many holes in P1? in P2?
- Place how many screws?
- extend
- 3-hole axially
- contour
- 2, 1
- 2 (proximal and distal)
Surgical Technique: TA screws:
- Enter joint how far between dorsal and palmar cortices?
- Drill (glide/thread) hole in P1 with ___mm bit
- Drill (glide/thread) hole in P2 with __ mm bit
- halfway
- glide hole, 5.5
- thread hole, 4.0
Arthrodesis to treat severe OA of pastern joint
- # of screws placed? Type of screw?
- engages as much of the ____ as possible.
- 2 or 3 lag screws
2. middle phalanx
A horse has lameness after insertion of 5-hole CDP and screws 8 months post surgery.
Tx?
Plate removal
Success rate for pastern arthrodesis is higher for forelimbs or hindlimbs?
hindlimbs
Clinical signs/Diagnostics of Complications from Pastern Arthrodesis:
1.
2.
3. Often due to ___
4.
- Increasing lameness
- Imaging
- cast
- CBC/ SAA, Fever = monitoring for infection
Bone spavin is a common cause of (forelimb/hindlimb) lameness
hindlimb
Bone Spavin definition:
DJD of distal intertarsal (DIT) and tarso-metatarsal (TMT) joints.
Bone spavin affects the (medial/lateral) aspect of the joint, and can result in significant _____ formation
medial
osteophyte
describe a horse with a “camped under” conformation
hindlimb is not caudal enough, and the cannon bone is not perpendicular to the ground
Radiographic Grading of Bone Spavin:
Describe Grade 1:
a very small osteophyte distolateral central tarsal bone
Radiographic Grading of Bone Spavin:
Describe Grade 2:
a small osteophyte proximal dorsolateral MTIII
Radiographic Grading of Bone Spavin:
Describe Grade 3:
A medium osteophyte distomedial central tarsal bone
Radiographic Grading of Bone Spavin:
Describe Grade 4:
A large osteophyte proximal dorsolateral MTIII bone
Causes of bone spavin?
chronic repetitive compression, torsion, and shear strains.
Common in western performances performing cutting/reining/roping/barrel racing
T/F: Distal limb flexion is a test used to diagnosis bone spavin
F, PROXIMAL limb flexion. Can also use blocks/radiographs/imaging
What is the main surgical treatment for bone spavin?
ankylosis
Medical managment of bone spavin involves:
- 2.
3.
4.
- IA injections of corticosteroids/chondroprotectives/autologous anti-inflammatories
- Phenylbutazone
- exercise adaption
- corrective shoeing
What surgical treatment for bone spavin decreases rotational and shearing forces?
Prognosis of this treatment method?
Cunean tenectomy
good to excellent
Performing ankylosis of TMT and DIT joints:
Methods:
1.
2.
- Mechanical - drill out joints using drill bit
2. Chemical - 70% ethanol, MIA (monoiodoacetate, no longer used), or Nd: YAG/Diode laser
Trans-articular drilling as tx of Bone Spavin:
- (medial/lateral) approach.
- approach distal to ____
- drill bit size?
- goal is to create…
- medial
- distal to cunean tendon
- initially 3.2mm, than 4.5mm
- create 3 drill tracts at 30 degree diverging angles
Pos-op care after drilling for Bone Spavin tx?
phenylbutazone, bandagin every 2 weeks, handwalking for 2 weeks post op, light right riding 3-4 weeks post op.
Surgical Ankylosis (drilling) tx method for bone spavin:
- What percentage range of horses return to soundness?
- Average time it takes?
- 59%-85%
2. 7.5 months
- How does laser facilitated ankylosis for bone spavin work?
- destroys cartilage by superheating and vaporizing synovial fluid.
what is the benefit of using laser facilitated ankylosis to treat bone spavin?
less pain/discomfort post op, and promotes partial ankyloses
What is the drawback of using laser facilitated ankylosis as treatment for bone spavin?
significantly less fusion of the distal tarsal joints compared with other techniques
Ethyl alcohol facilitated ankylosis:
Lameness resolved in ___% of horses with bone spavin within 3 months
86%
Why do we no longer use monoiodoacetate injections as a chemical method of treating bone spavin?
is has considerable morbidity, severe post-op pain, and has the potential for severe complications (PIT joint communication)
Fracture of proximal phalanx:
75% are in the (forelimb/hindlimb)?
forelimb
Drilling for P1 fracture:
Describe the location of the most proximal screw?
additional screws placed at ___-___mm intervals
within 5 mm of sagittal grove
20-22mm
P1 fracture:
- Post-op care?
- Prognosis depended upon _____ and ____
- Distal limb cast 2-6 weeks
2. resultant fetlock and pastern DJD
How would you treat an incomplete P1 fracture?
Lag screw or cast only, STRICT STALL REST
Treatment of comminuted P1 fracture?
fetlock arthrodesis as a salvage procedure. They aint returning as athletes
Indications for Fetlock Arthrodesis?
1.
2.
3.
- complete rupture of SDF, DDF, and suspensory ligament
- septic arthritis
- Fractures: Medial and lateral sesamoid, cannon bone, P1
