LECTURE SCRIPT

ORTHOPEDIC INJURIES


The presentation today concerns orthopedic injuries. The wide range of injuries commonly seen provides a furtile ground for frequent patient visits to the emergency department. Because of the very nature of these complaints, it is very important that all physicians have a firm understanding of the proper methods of describing an injury to the consulting orthopedic surgeons and of the emergency department treatment for a wide variety of orthopedic injuries.

The goals and objectives for this discussion include defining the proper nomenclature for describing fractures, dislocations, sprains, and strains. We will describe the basics of splinting and fracture care. Due to time constraints we will not be able to demonstrate the types of casts or splints involved with any specific injuries; nor will we be able provide any hands-on training at this time.

We will discuss the common complications that are associated with orthopedic injuries and we will discuss the basic assessment and treatment of sprains and strains.

We will begin our discussion with basic fracture nomenclature. A complete fracture is one that interrupts both cortices of a bone. An incomplete fracture involves only one.

A closed fracture is one in which the skin and overlying soft tissues remain intact. There is no break in the skin. An open fracture does have a break in the integrity of the skin therefor the bone is exposed to the outside environment.

A complicated fracture is one that is associated with either neurovascular, visceral, ligamentous, or muscular damage. Intra-articular fractures are also included in this group. An uncomplicated fracture is one that has only a minimal amount of associated soft tissue damage. We will discuss the various associated injuries later in this discussion.

A direct fracture is one in which the fracture is the result of forces applied at the fracture site. An example of this would be the “nightstick” fracture of the forearm. An indirect fracture results from forces that are transmitted to the fracture site. An example of this would be an avulsion fracture.

Fractures can also be described in relation to the long axis of the bone. A transverse fracture extends at a right angle to the long axis of the bone. An oblique fracture travels obliquely to the long axis of the bone, while the spiral fracture runs in a spiral fashion along the long axis of the bone.

A fracture is described as comminuted when there are more than two fragments. A greenstick fracture is an incomplete, angulated fracture of long bones which occurs primarily in children.

Fractures can also be described in terms of there anatomical relationship to the bone involved. First is just the name of the bone itself, such as humerus or femur. Then simply the side involved, right or left. Fractures can also be described in relationship to predetermined reference points. Long bones can be divided into thirds - proximal, middle, and distal. A precise modifier may be used when it exists.

Fracture fragments are described relative to their normal position. Any deviation from the normal position is termed displacement. The position of the distal fragment is described relative to the proximal fragment. Alignement refers to the longitudinal axis of one fracture fragment to the other. Any deviation is termed angulation. The fracture is described relative to the direction of the apex of an angle formed by the two fracture fragments.

An avulsion fracture is one in which a bone fragment is pulled away from its normal position by the forceful contraction of a muscle or by the resistance of a ligament to a force applied against it. An impaction fracture refers to the forceful collapse of one bone fragment into another.

A pathological fracture occurs through an abnormal area of bone. This is most frequently either a primary or a metistatic cancerous lesion.

A stress fracture occurs through an area which receives repetitive low energy trauma which leads to bone resorption and a subsequent weakened area.

There are several types of fractures which are commonly associated with children. The greenstick fracture is an incomplete, angulated fracture of long bones. A torus fracture is an incomplete fracture charachterized by buckling of the bone cortex of a long bone. The Salter Harris classification describes fractures which occur in relation to the epiphyseal growth plate. A Type I fracture involves only displacement of the epiphysis. The fracture occurs through the epiphyseal plate. A Type II fracture is the same as a Type I with the exception that a small triangular segment of the metaphysis is involved. A Type III fracture involves a slip of the growth plate plus a fracture through the epiphysis extending into the articular surface. Type IV fractures are the same a Type III with the addition of a metaphysis fracture. A Type V fracture is a crush injury to the epiphyseal plate. As can be seen in this quick discussion on fracture nomenclature there is a lot of overlap in the methods that can be used to identify a fracture. The most descriptive terminology that will convey the most information to the consultant is desired.

The general goals of fracture splinting are to relieve pain, protect against further soft tissue injury which might occur if sharp bone fragments are allowed to move, and to protect against further fracture segment displacement which might convert a simple closed reduction fracture into one which might require open reduction.

In the delivery of emergency care in the prehospital setting numerous commercially prepared devices are available. Some of the more commonly seen include the cervical collar, air splints, Hare traction splints, Thomas ring splints, and the Sager traction splint. The splint is applied as the injured area is found except in the circumstance of a severely angulated extremity fracture which should be straightened prior to the application of a splint. Other indications for reduction in the field include vascular compromise and severe pressure on the soft tissues by the bone fragments. The splint is standardly applied to extend beyond the joint both above and below the fracture site.

In the emergency department the general concepts of fracture care are the same as in the prehospital setting. the application of splints or casts can be performed in the emergency department which can be customized to the needs of each patient utilizing Webril and either plaster or fiberglass splinting material. The application of casts is frequently not performed by emergency department personnel but there is institutional variability in regards to this.

The care of open fractures warrants special consideration. The control of hemorrhage begins in the prehospital setting with the use of sterile pressure dressings. The fracture is splinted without reduction unless there is evidence of vascular compromise.In the emergency department the wound is irrigated with copius quantities of normal saline preferably under pressure. Intravenous antibiotics are begun utilizing a cephalosporin and tetanus prophylaxis is administered as required.

The complications associated with fractures include potentially life threatening hemorrhage. In adults, blood loss from a fracture may range from 100 ml in a simple forearm fracture to 3L in a pelvis fracture.

Certain fractures are associated with a high incidence of vascular injury. Examples of this include fractures or dislocations of the knee which puts the popliteal artery at risk or distal humeral fractures which puts the brachial artery at risk. During the initial screening examination it is imperative to accurately assess the presence of pulses and the capillary refill. Signs of serious vascular injury may range from very subtle changes to extreme pain, pallor, pulselessness, paresthesias, and paralysis distal to the injury site.
Late complications include thrombosis, arteriovenous fistulas, aneurysm,
false aneurysm, and tissue ischemia with limb dysfunction.

Nerve injuries may occur with fractures. Neuropraxia is the contusion of the nerve. Paralysis, if present, is temporary and sensory loss is minimal. Axonotemesis is a more severe crushing injury to the nerve. Healing is still possible but is prolonged. Neurotemesis is the complete severing of a nerve. All neurological function distal to the injury site is lost. Recovery without primary repair is unlikely. Common fractures associated with nerve injuries include shoulder dislocations and the axillary nerve, elbow fractures and median or ulnar nerve, sacral fractures and cauda equina, acetabulum fracture and sciaticc nerve, hip dislocation and femoral nerve, and knee dislocations with tibial or peroneal nerve injuries.

Compartment syndrome is an increase in the intra-compartment pressure of an extremity which leads to vascular compromise and pressure on nerves. The signs of developing compartment syndropme includes the 5 P’s - pain, pallor, paresthesias, pulselessness, and paralysis. If unrecognized may lead to Volkmann’s contractures. Treatment is fasciotomy.

Fractures may also be associated with avascular necrosis. The most common associated site is the navicular bone in the wrist. The fat embolism syndrome is most commonly associated with long bone fractures in young adults and hip fractures in the elderly. ARDS is the earliest and most common manifestation. Restlessness, confusion, and a petechial rash may also be seen.

A dislocation occurs when there is complete disruption of the joint surface with loss of normal contact between the two bony ends. A subluxation is the partial disruption of a joint with partial contact remaining between the two bones that make up the joint. Diastisis is the disruption of the interosseus membrane between the two bones involved in a syndesmotic articulation.

In general dislocations are named for the major joint involved. In three-bone joints, injuries are named for the joint involved if the disturbance involves the two major bones or if the lesser bone is involved, the disturbance is named for that bone. An example of the former would be a dislocation of the elbow which involves the humerus and ulna; whereas, a radial head dislocation involves the radius and ulna in the elbow. The dislocation is described according to the direction of the displaced segment relative to the normal structures. If the dislocation is associated with a fracture it is termed a fracture-dislocation. If there is an associated disruption of the overlying skin it is termed an oped dislocation. It is possible to have an open fracture-dislocation.

A dislocation is generally associated with severe pain. The neurological and vascular status must be evaluated identical to that of a fracture. X-ray studies are generally obtained both pre- and post-reduction in any initial or complicated dislocation. In a patient with a history of recurrent dislocations, post-reduction x- rays may be all that is necessary.

The treatment of a dislocation should be performed as rapidly as possible utilizing adequate analgesia or anesthesia as required. The longer a dislocation remains unreduced the more difficult the reduction may become secondary to muscle spasm surrounding the joint. The general rule is to recreate the injury by pulling the proximal end of the dislocated bone out and away from whatever is trapping it. Open reduction may be required in some circumstsnces. There are specific techniques which may be used to reduce specific joints. An emergency medicine procedures text is a good place to review each of the most common dislocations for its specific reduction technique.

Sprains are defined as an injury to the fibers of a supporting ligament of a joint. The injuries are graded according to the severity of the pathological findings. A first degree sprain involves the minor tearing of ligamentous fibers with associated mild hemorrhage and swelling. There is minimal point tenderness at the injury site. Stressing the ligament will produce some pain but there is no opening or abnormal joint movement. A second degree sprain involves the partial tearing of ligamentous fibers associated with moderate hemorrhage and swelling. There is moderate point tenderness, painful motion, and loss of function. There is a tendency toward persistent instability and recurrence. A third degree sprain involves the complete tearing of the ligament. There is exaggeration of second degree signs, and abnormal joint movement.

The presentation of a sprain is similar to that of a fracture. A careful history and physical exam is required. The reconstruction of the mechanism of injury will enable the localization of potential injury sites. X-rays may be required but often no specific findings are found. In children due to the relative strength of the ligaments, epiphyseal injuries are more common than ligamentous injuries.

The initial management of sprains includes RICE - rest, ice, compression, elevation and analgesics. The joint should be immobilized and the patient should be instructed in non-weight bearing walking. Third degree sprains require urgent follow-up. Less severe injuries may be followed in 3-7 days.

Strains are defined as an injury to a musculotendinous unit resulting from violent contraction or excessive forcible stretch. Strains are graded identical to sprains. With a first degree strain there is minor tearing of the
musculotendinous unit with associated spasm, swelling, local tenderness,
and minor loss of function. In a second degree strain more of the fibers are torn but without complete disruption. There is marked swelling, ecchymosis, muscle spasm, and loss of strength. In a third degree strain there is complete disruption of the muscle or tendon.

In the assessment of strains, force applied to the muscle produces pain at the site. There may be a palpable defect at the site.

Treatment is similar to that for sprains - rest, ice, elevation, and analgesics.
Physical therapy may be indicated with a goal of prevention of future injuries through muscle stretching and strengthening.

We have quickly discussed the nomenclature involved in describing orthopedic injuries. Accurate communications is the goal.Treatment for the most part is conservative except for some fractures which require open reduction by their nature. There are many excellent orthopedic and physical assessment texts which may be consulted for further information.