LIFE “We must be willing to get rid of the life we’ve planned, so as to have the life that is waiting for us.” -Joseph Campbell

DISEASES OF THE MUSCULOSKELETAL SYTEM

FUNCTIONS OF THE MUSCULOSKELETAL SYSTEM Support (skeletal system) – structural support/framework for the entire body Storage – Minerals (calcium) and lipids. Blood cell production. – site of formation for all types of blood cells. Protection – vital organs of the body ribs surround the visceral organs central nervous system is encased within the skull and spinal cord. Leverage – Many of the joints of the body act as levers therefore assisting with movement. – Provides a place for muscles, tendons, ligaments to attache

REVIEW - Bone anatomy Epiphysis is the enlarged area at either end of the bone Diaphysis is the long shaft in the middle portion of the bone Metaphysis is the joining point between the epiphysis and diaphysis The periosteum is the fibrous covering around the outside of the bone not covered with articular cartilage. The endosteum is the fibrous and cellular tissue lining the medullary cavity of the bone

REVIEW – Shapes of Bones humerus, radius, femur, tibia, metacarpals, and metatarsals carpal and tarsal bones sternum, ribs, scapula, and certain skull bones vertebrae and certain facial bones patella, and proximal and distal sesamoid bones of the digits.

MUSCULOSKELETAL SYSTEM The skeleton is the rigid frame Flexible articulations form joints Muscles, tendons, and ligaments form a system of pulleys

MUSCULOSKELETAL SYSTEM FUNCTIONS

MUSCULOSKELETAL SYSTEM DISRUPTION:

TRAUMA: CLINICAL SIGNS OF LONG BONE FRACTURES lameness Deformity of bone, swelling Lameness, swelling, hx of abuse

TRAUMA: CLASSIFICATION OF FRACTURES – Open (compound) – broken skin – Closed – intact skin – Simple (1 break): oblique, transverse, incomplete fractures – Comminuted –multiple pieces – Stable – ends opposed and fixed (ie. greenstick) – Unstable – Compression: vertebrae

TRAUMA: DIAGNOSIS OF LONG BONE FRACTURES Transverse fracture Oblique fracture

TRAUMA: DIAGNOSIS OF LONG BONE FRACTURES Comminuted fracture Greenstick fracture

TRAUMA: DIAGNOSIS OF LONG BONE FRACTURES Fissure fractures

TRAUMA: DIAGNOSIS OF LONG BONE FRACTURES Spiral Fractures

TRAUMA: DIAGNOSIS OF FRACTURES COMPRESSION FRACTURE SALTER-HARRIS FRACTURES OF THE EPIPHYSIS

TRAUMA: OPEN VS. CLOSED FRACTURES In open fractures bone is exposed through the skin

TRAUMA: METHODS OF FIXATION OF LONG BONE FRACTURES SPLINTS It is critical that the splint support both the joint above and below the injury !

TRAUMA: METHODS OF FIXATION OF LONG BONE FRACTURES Splints METASPLINT ROBERT JONES BANDAGE

TRAUMA: METHODS OF FIXATION ON FRACTURES SCHROEDER-THOMAS SPLINT Immobilize any fracture Distal to midhumerus or midfemur

CASTS Casts can be made for the entire body, as for spinal injuries, for any portion of the body (spica cast), or for just the extremities.

TRAUMA: METHODS OF FIXATION OF FRACTURES IM (Steinmann) pins with cerclage wires

TRAUMA: METHODS OF FIXATION Advantages of IM pins – Prevent bending forces Disadvantages – Do not prevent rotation or compressive (axial) forces Should be combined with other methods such as cerclage wire to prevent other forces

TRAUMA: METHODS OF FIXATION OF LONG BONE FRACTURES Bone plates and screws D0

TRAUMA: METHODS OF FIXATION External fixators are pins that penetrate the skin and bones that are attached to fixed bars or acrylic using special clamps: Kirschner-Ehmer apparatus

TRAUMA: CLIENT INFO Restrict activity Watch for drainage, swelling, heat Metal (plate, pin) stronger than bone – refracture may occur Follow up x-rays necessary Metal should be removed after healing Metal may cause cold sensitivity

Ligament Injury – Anterior Cruciate Ligament Rupture ACL and PCL (posterior cruciate ligament) – stabilize knee joint – Intra-articular structures Ruptured ACL – most common stifle injury and leads to DJD – May be complete rupture or partial tear => unstable joint => DJD

TRAUMA: CRUCIATE LIGAMENT INJURY/RUPTURE

TRAUMA: CLINICAL SIGNS OF CRANIAL CRUCIATE LIGAMENT INJURY/RUPTURE Highly active, athletic animals Middle-aged obese dog

TRAUMA: CLINICAL SIGNS OF CRANIAL CRUCIATE LIGAMENT INJURY/RUPTURE Animal is acutely non wt. bearing on the rear leg after hyperextending the stifle joint Joint effusion

TRAUMA: CRANIAL CRUCIATE LIGAMENT RUPTURE Cranial drawer test Tibial compression test

TRAUMA: CRANIAL CRUCIATE LIGAMENT RUPTURE

TRAUMA: CRANIAL CRUCIATE LIGAMENT RUPTURE REPAIR Extra-articular Stabilization *Most successful in patients less than 15kg

TRAUMA: CRANIAL CRUCIATE LIGAMENT RUPTURE REPAIR Intra-articular stabilization – Over-the-top patellar tendon graft

TRAUMA: CRANIAL CRUCIATE LIGAMENT RUPTURE

TRAUMA: CRANIAL CRUCIATE LIGAMENT RUPTURE REPAIR Intra-articular stabilization technique TPLO – Tibial Plateau Leveling Osteotomy

TRAUMA: CRANIAL CRUCIATE LIGAMENT RUPTURE

TRAUMA: CRANIAL CRUCIATE LIGAMENT RUPTURE – CLIENT INFO Restrict activity 3-4 weeks post surgery – Cage rest – Leash walk only to urinate and defecate Gradually increase exercise 4-8 wks post sx Full activity 8-12 weeks Opposite cruciate often tears within 1 yr Weight loss helps DJD of stifle joint likely If no surgery, joint thickens - fibrosis

POOR CONFORMATION: LUXATING PATELLA

PATELLA IN GROOVE PATELLA OUT OF GROOVE

POOR CONFORMATION KNOCK-KNEED/PIGEON-TOED, OR COW-HOCKED STANCE MAY OCCUR IN LATERAL LUXATIONS BOW-LEGGED STANCE MAY OCCUR IN MEDIAL LUXATIONS

POOR CONFORMATION: TREATMENT OF PATELLAR LUXATION TROCHLEAR WEDGE RESECTION

POOR CONFORMATION: TROCHLEAR WEDGE RESECTION

POOR CONFORMATION: TIBIAL CREST TRANSPOSITION