Overview Flashcards
What is orthopedics
is the medical discipline devoted to the musculoskeletal (MSK) system.
Orthopedic surgery is the medical science concerned with restoring and preserving the normal function of the MSK system.
What are 3 functions of the MSK system
Support
Protection
Movement
What are the 6 elements of the MSK system
Bone – provides support
Cartilage – provides smooth surface for articulating bones
Intervertebral Disks – sustains and distributes loads
Muscle – contract to create movement
Tendons – connect muscle to bone
Ligaments – connects two bones
Cells of the bone
Osteoblasts make new bone
Osteoclasts remove necrotic bone
What are the 2 types of bone
Cortical bone – less porous, denser outer portion of bone.
Cancellous bone – more porous, trabecular bone – surrounded by cortical bone
What are 2 reasons there might be a fracture?
Fx’s occur when a single momentary load on a particular bone exceeds the tolerance of that bone – usually the result of trauma
Fx’s may also occur from repeated loading that leads to bone fatigue and failure – which is a stress fx.
What are the 5 steps of fracture healing
Impact Inflammation Soft callus formation Hard callus formation Remodeling
Impact- Fracture Healing
application of force/energy resulting in fracture.
Inflammation- Fracture Healing
Hematoma formation at fx site.
Granulation tissue replaces hematoma
Fibroblasts make collagen
Osteoclasts remove necrotic bone
Soft callus formation- Fracture Healing
After inflammation soft callus forms uniting the fracture fragments.
Hard callus formation- Fracture Healing
Soft callus becomes hard callus and the bone appears clinically healed.
Remodeling- Fracture formation
Final stage of fx healing – bone is already healed and now is reshaped back to normal shape.
What is ORIF
open reduction and internal fixation
What happens during surgery for Fx?
First the surgeon exposes the fx, cleans things up, reduces the fx and temporarily maintains reduction while applying the appropriate fixation device. At the conclusion of surgery immobilization is required so the bone heals in the right position.
What happens after surgery?
This usually means a cast application – often uni or bi-valved (split) to allow for post-operative swelling.
Once swelling reduced a more appropriate cast for weight bearing activities may be applied.
Fx’s having undergone ORIF heal more quickly than conservatively Rxed fxs – but are more at risk for infection, complications of anesthesia or surgery.
Factors that influence Fx Healing
Site of the fx Blood supply Age & nutritional status Apposition of fx fragments Adequate immobilization of fx site Presence of soft tissue interposed at fx site Infection
What 2 things can happen when a Fx fails to heal properly
Non-union
Malunion
Non Union Occurs during?
There is a poor blood supply (elderly are more at risk).
Poor nutritional status
Inadequate immobilization
Soft tissue interposed between fx fragments.
Presence of infection or dead bone (sequestrum)
Treatment for Non Union
Most technologically advanced means of dealing with a non union is using the Ilizarov method.
This involves the application of an external fixator.
External fixator can then be adjusted and bones distracted or compressed.
Bony regeneration occurs at the rate of 1mm per day.
what is malunion of a Fx
Bone healing has occurred but with an unacceptable degree of angulation, rotation or shortening.
In the L.E. leg length discrepancies of
> 1” are not tolerated well.
Ilizarov method can be used here as well.
Complications of Fx
Nerve Damage
Closed fx’s are less likely to have complete transections of nerves and so more likely to recover function.
Open fx’s are more likely to be associated with nerve transections.
Infections
Signs and Symptoms of Fx complications
Fever/increased pain/redness
Purulent drainage
Culture of pus yields organism – usually staph
Stress Fractures
Repeated load stresses to a weight bearing bone (often the tibia) results in micro injuries that cause resorption.
This causes intrinsic weakening of the bone stress fx.
Often occurs in athletes who increase their activity too abruptly.
Also occurs in individuals who go from sedentary to highly active lifestyles
Clinical Presentation of Stress Fractures
Long hx of achey pain in affected areas (tibia, distal fibula, metatarsal).
There may be a precipitating event.
Pain is further aggravated by activity.
Pain occurs with both loading and unloading of bone.
Pts may have deformity or swelling.
Radiographic findings for stress fractures
Plain x-rays may be normal.
X-rays may show some subtle cortical disruption or evidence of prior bone healing.
Bone scan is usually more helpful.
CT and MRI are expensive and may be of limited value.