Orthopedics “Orthopedics” is: that branch of surgery which is specially concerned with the preservation and restoration of the function of the skeletal system, its joints, and associated structures like ligaments and tendons
Orthopedic Exam • Meet Sam & Simon!!
BONES Major Functions: 1. Support for body’s vital organs (ie. skull protects the brain, rib cage protects the heart & lungs) 2. Serve as levers in conjunction with joints, tendons, ligaments, and muscles for movement 3. Production of blood cells in bone marrow 4. Storage site for calcium & phosphorous
Types of Bone - Compact Bone – bone’s outer layer, what we can see. It is dense, strong, and heavy - Spongy Bone – bone’s inner layer; self- organizes in response to the direction of weight put on it http://training.seer.cancer.gov/module_anatomy/unit3_4_bone_classification.html Anatomy of a Typical Bone
Associated Structures • Joint – anytime 2 or more bones come together • Articular Cartilage – cartilage covering the ends of bones that are in contact with adjacent bones to create smooth movement and shock absorption • Tendon – connects muscle to bone • Ligament – connects bone to bone
Classification of Bones • Long Bones – long! Bones of limbs • Short Bones – short! Small bones of hands & feet • Flat Bones – flat! • Sesamoid Bones – small bones embedded in tendon as it crosses a bony prominence. • Irregular Bones – jutting processes give these bones an irregular shape.
Quiz • Can you feel some of these bones in your own body? - where would you feel flat bones? - where would you feel a sesmoid bone (and its associated tendon)? - where would you feel short bones - where would you feel irregular bones?
Open Closed Complete Incomplete Comminuted Segmental Chip Slab Pathologic Types of Fractures
Pathologic Fracture • Fracture secondary to another disease process
Bone Re-Modeling • Osteoblasts – secrete a matrix made up of calcium phosphate crystals • Osteocytes – retired osteoblasts; found within bony wall that they have deposited around themselves • Osteoclasts – break down bone; release acids to dissolve crystals and enzymes to break down matrix
Bone Reacts to Stresses Put on It • Greater physical stress placed on a bone at a particular site results in more bone deposition by osteoblasts at that site • Another theory suggests electrical field change created by physical stress stimulates osteoblasts & matrix formation
Fracture Healing • Primary Bone Healing – occurs when there is an anatomic reduction with compression fixation • Secondary bone healing – occurs with a fibrous connective tissue “bridge” that is replaced by bone
Abnormal Fracture Healing • Mal-union – a fracture that heals with abnormal alignment • Non-union – fracture healing has STOPPED before completely healed - elephant foot “hypertrophic non-union” - tapered “atrophic non-union” • Sequestrum – a dead bone fragment separated from the rest of the bone • Osteomyelitis – infection of bone
Treatment Options • Fracture Reduction - Closed * temporary (until surgery) * permanent (cast or splint) - Open (orthopedic surgery) • Intramedullary Fixation • Cerclage • External Fixation Devices
Fracture Reduction Goals • Get bones close enough to heal • Proper alignment - avoid mal-union + loss of function • Avoid additional trauma - further fracture - infection
TITAN continued … • Treatment: Surgery - Wedge osteotomy of femoral condyles, plate applied - Deepening of patellar groove - Tibial crest movement back to cranial, pins applied - Patella was sutured medially to fixate in groove - Extra joint capsule on medial surface of joint was removed
Follow-Up • Re-Check in 2weeks for range of motion • Re-check in 4weeks for progress of healing • Recheck in 10weeks for further progress of healing STRICT CAGE REST DURING THIS TIME!!
Animal Orthopedics as Human Model • Animals are frequently used as models in clinical studies or experiments in the development of surgical procedures & drugs in veterinary medicine to be used in human medicine! 1st hip replacement surgery was developed in military dogs
END • All images used from government websites as indicated OR with permission from Dr. Sharon Kerwin & Dr. Ben Young, Texas A&M University College of Veterinary Medicine