• Proprioception determines limb placement

Gait Analysis

• TROT is the most important gait for evaluating lameness
• Forelimb lameness assessment involves checking for head bob, access for head bob, where "DOWN on SOUND" means head goes down when the sound limb is weight baring
• Hindlimb lameness is indicated by a shortened stride length on the lame leg compared to the normal limb
• Lameness can be scaled from 0 to 4, with 3-4 being severe and 4 indicating non-weight bearing

Muscle Atrophy

• Muscle atrophy commonly occurs at the spine of the scapula, greater trochanter, and quadriceps

Palpation

• Palpate for symmetry and any atrophy/hypertrophy compensation as well as lumbosacral pain through dorsal palpation
• Differentiate hip pain from lumbosacral pain by assessing whether pain occurs without unloading or loading hips
• Medial joint check can indicate CCLR, as shown by a "medial buttress"
• Neuro exams important in Ortho exams

Localization

• Start at the most distal leg
• Move joints into their full range of motion
• Apply stress medially and laterally to each joint, assessing for laxity
• Palpate each joint for pain, heat, swelling, and instability

Ortolani Sign

• Apply dorsal pressure to a flexed stifle while applying counterpressure dorsal to the pelvis to check for subluxation
• Slowly abduct the limb; a positive sign for hip dysplasia is indicated if the femoral head reduces back into the acetabulum

Cranial Drawer Test

• One hand is placed on the tibia with the index finger on the patella and thumb on the fibular head
• The other hand is on the femur with the thumb on the lateral fabella and index finger on the tibial tuberosity
• The tibia is moved cranially in relation to the femur. A positive test for CCLR is 1-2 mm of movement

Tibial Compression Test

• With the tarsus flexed, the tibia is moved forward, which indicates a "tibial thrust" and CCLR

Patella Luxation

• One hand holds the patella while the other flexes the stifle using the tarsus, lateral patellar ligament is working (LPL)
• Assessment when stifle is extended means the medial patellar ligament is working (MPL)

Fracture Assessment Score

• The fracture assessment score ranges from 0-10, which is based on biological factors, mechanical factors, and clinical factors
• 0 = good, 10 = BAD

Fracture Reduction

• Fracture reduction involves either reconstructing fragmented bones to their normal position or restoring normal limb alignment

Physiological Processes

• It's crucial to overcome physiological processes like muscle contraction and fracture fragment overriding

Closed Reduction

• Closed reduction involves reducing fractures or aligning limbs without surgery
• Used for greenstick fractures, nondisplaced long bone fractures, or comminuted nonreducible diaphyseal fractures treated with external fixators
• Best for preserving soft tissues and blood supply

Open Reduction

• Open reduction involves surgery to expose fractured bone segments for comminuted nonreducible diaphyseal fractures, articular fractures, and simple fractures
• Great for visualization, implant placement, bone reconstruction, and cancellous bone grafts
• Negatives include increased surgical trauma, diminished environment, and increased likelihood of bacteria
• “Limited open reduction” with only a small exposure: transverse fractures can be levered into position & oblique fractures manipulated with lag screws or cerclage wire

Open but Don't Touch Reduction

• Realigning bone and placing a plate, but not manipulating fragments or hematoma

Direct Reduction

• Involves counteracting muscle contraction or manually distracting segments
• Bone ends lifted & brought into contact and forces slowly applied, Splint in place
• A precaution in using rough bone handling due to the potential for forming fragmentation and fissure fracture lines; use cerclage wire if fissures are present
• Bone-holding forceps are used to reduce large butterfly fragment fractures

Indirect Reduction

• Process that restores limb alignment by distracting major bone segments
• Used for Non-reducible fractures where can't apply load sharing
• Use IM Pin, animal's weight (limb suspended in air or table raised)

Bone Grafting

• Allograft: bone transplanted from one animal to another of same species, the MOST common

Biomaterials

• Demineralized bone matrix composed of inorganic and organic components, including collagen

Synthetic Bone Substitutes

• Ex: tricalcium phosphate ceramics, bioglass, polymers
• Composites of osteogenic cells that contain osteoinductive growth factors. Mesenchymal stems cells mature into osteoblasts

Cancellous Bone Autografts

• The GOLD standard when optimal bone healing is NOT anticipated
• For elderly pets with fractures, delayed unions, nonunions, joint arthrodesis or promoting bone formation in infected sites
• Negatives – increased surgical time, morbidity, potential donor site complications and small/old pets
• Harvested from any long bone metaphysis
• Site depends on accessibility of area during fracture sx repair (what limb is close to site)
• Harvested AFTER fx stabilization but BEFORE primary ortho procedure to limit air exposure

Cortical Bone Autografts

• Cortical bone removed without affecting function
• Ex) Mandibular fractures
• Segmental graft: placed between fracture segments

Sliding Onlay Graft

• Placed OVER fracture site

Cancellous Bone Allografts

• Frozen grafts commercially available
• Good as reduced OR time, availability, and no morbidity at donor site (different animal used)
• Cons is expense and lack of osteogenic properties

Demineralized Bone Matrix (DBM)

• Created from processed allograft bone
• Can EXTEND cancellous bone autograft
• 50:50 combination DBM available for cats and dogs

Fracture Fixation Systems

• External coaptation best at providing patient comfort & decreased ST damage
• Also used as primary repair method. MUST be at least 50% reduction of segments at fracture site on 2 radiographic views = bone heal
• Examples: bandages, splints, casts applied only for fractures of distal limbs

External Skeletal Fixators

• Indicated for long bone fractures, corrective osteotomies, joint arthrodesis, and temporary join immobilization
• NOT indicated for articular fractures--must be open surgery
• Post closed reduction for communicated fractures
• Adjust- tightening and loosening of pin

Linear External Fixators

• of planes occupied by frame

• of sides of limb where fixator protrudes

• Ex) Unilateral-uniplanar (type Ia), unilateral-biplanar (type Ib), bilateral-uniplanar (type II-very strong and stiff), bilateral-biplanar (type III)

Linkage Clamps

• Joint fixation pins connected to connecting bar
• Larger holes towards connecting bar
• Smaller holes in fixation pins

Ways to Increase Strength & Stiffness Using External Fixators

• Predrill BEFORE inserting pins
• Increase pin #s with max 4 pins per bone segment
• Increase pin size by up to about 25% bone diameter
• Locate pins near joints and fracture
• Decrease distance between bone and pin-clamp interface Increase connecting bar size and planes

Circular External Fixators

• Used to stabilize fractures, transport bone segments, and correct bone angular and length deformities
• Unique rigid fixator for controlled distraction of bone (“distraction osteogenesis”) → creates new bone formation

Intramedullary Pins

• Used for diaphyseal fractures in humerus, femur, tibia, ulna, and metacarpal/metatarsal bones
• Contraindicated for radius because the insertion point of pin interferes with carpus
• Biomechanical advantage = applies equal resistance to bending loads in any direction

Biomechanical Disadvantage

• Poor resistance to axial/compressive loads and rotational loads
• There is a lack of fixation as it interlocks with bone
• Supplements (cerclage wire, external fixator, or plate) are required to provide rotational and axial support

Application

• Span LENGTH of bone with IM pin
• Retrograde or normograde pin insertion
• Check pin location with reference pin and by manipulating joint

Cerclage Wire Usage

• Smaller cerclage
• Use pin that's 60-70% of medullary canal width
• Smaller pin with external fixator with pin %50-60% of canal width
• Larger with bone plate with pin %40-50% of canal width

Steinmann Pins or Krischner Wires

• "Crossed pins"
• Indicated for metaphyseal and physeal fractures (ex: Salter Harris fractures)

Interlocking Nails

• Stabilize simple and communicated mid diathesis femoral fractures
• Secured by proximal & distal transfixing screws for axial, bending and torsional stability
• The largest nail which fits bones and a span length is required
• Position nail screw holes 2cm away from fracture
• Secure nail with 4 screws or fixation bolts = optimal fixation

Orthopedic Wire

• Used as supplement, provides axial, rotational and bending fracture support
• Placed around circumference of bone
• Provides additional stability by getting compression between bone fragments, ONLY used to hold fragments in position. Never use alone. Also Hemicerclage or interfragmentary wire is also used
• Most commonly used implant, but can be misused
• Hemicerclage or interfragmentary wire is used when fracture length is less than 2x bone diameter and is placed through pre drilled holes in bone

3 Criteria when determining to use Cerclage Wire

• (1) Length of fracture must be 2-3 times diameter of marrow cavity
• (2) Maximum of 2 fracture lines are present
• (3) The fracture must be anatomically reduced
• A common cause of failure for cerclage wires is attempting to provide stability for multifragmented fractures of bone which are prone to collapse

Application to Cerclage Wire

• Use only for anatomically reconstructed, short, oblique, or spiral fractures

Steps to apply cerclage wire

• (1) apply a series of cerclage wires on fracture line

Bone Axis

• (1) Space wires ½ - 1 bone diameter apart and at least 0.5cm/5mm from fracture

Steps to apply cerclage wire

• (1) Twist ends by hand then start with needle holders to twist and tighten wire by pulling and twisting
• (2) Tighten and cut wire 3mm from start of twist or start wire 5-7mm from twist and bend in direction of twist

Tension Bands

• Indicated for avulsion fractures
• Converts destructive tensile forces into compressive forces
• Contraindicates the force of muscle contraction in order to compress fracture surface

Application

• (1) Use K-wires or small Steinmann pins
• (2) Place pires PARALLEL to each other and PERPENDICULAR to fracture

Wires for Tension Bands

• Place the hole for the wire the same distance below the fracture compared to pins above the fracture
• Tighten the wire in direct contact with the bone

Bone Plates and Screws

• Indicated for complex or table fractures with prolonged healing
• Compression plate which aids fractures transversally and screw is meant for fractures
• Neutralization plate for long oblique fractures which Protects reconstructed bone from torsional bending and sharing forces
• Plating is meant for plates w/o pin to span fracture

Bridging Plate

• Place IM Pin with plate to span nonreductible fracture Plate with screws

Locking Plate

• Prevents collapse of adjacent articular surface with screws secured in place
• Application that is bone-conforming

Screws

• Should first be applied in order to pull bone to plate during plate conforming of size

Lag Screws

• Compress Fracture line between 2 bony fragments, position optimal for placement perpendicularly

Short Oblique Fractures

• Use bisect angle where screw placed between lines 90 degrees to fracture surface and 90 degrees to long axis of bone. This prevents slipping fragment

Fracture

• If hole located near cortex, diaphysis, hole equals diameter

Key Concept

• (1) Place Reduction and secure fracture before lag screw in terms with compression
• Place screw perpendicular to fracture with partially threading for a threads screw

Canine Hip Dysplasia

• Hereditary condition of coxofemoral that characterized by subluxation or complete luxation of femoral head characterized by hip laxity Laxity of Hip
• Increased joint fluid volume, Proliferative fibroplasia of joint capsule, increased trabecular bone thickness
• Most prevalent genetic based Ortho disease, most highest in Large Breed dogs affects male & female
• Occurs due to Excersice Intolerance which is the most common indicator

Symptoms

Young dogs experience pain fiber. Chronic dog have stretching of bone

Treatments

• Rest For : 10.14days, HEat, PT &NSAIDs -Short Term management , Weightloss , Exercise and NSAIDS for Long Term management

Surgical Treatment

• TPO cutting and repositioning bone which requires aspects of Illium & Ischium which are pupis, wing

FHO

• FHO is indicated is clinical signs can't medically, such as dysplasia

Coxofemoral Luxation

• Femoral Head replacement from Acetabulem which can be treated be open reduction or medical management

Surgical Treatment.

Open Reduction

Toggle Rod Suture

The best procedure is closed reduction with a 50% maintenance of success

Post Operative

• Manage with controlled Rehab

Diagnosing Hip Dysplsia

Measure to see greater trochanter and tuber Ishcii

Orthopedic Foundation Animals

• To control Dysplasia, patients registering are at least 25 months old and checked by a license professional which is a bit biased

HIP

• Stress and measures at the international level, less hip dysplasia Medial and Patellar dislocations

• Open Reducation which is the most salvageable with Recongnizable conformation

Closed Reducation

Best is closed reduction with a 50% maintenance of success

Post Operative care

• Manage with controll and Rehab

• Comparing with hip helps w/ Contralateral Hips . And use of Emyer Sling and prevent Clipping for post