Femur Immobilization

Anatomy and Physiology

The femur is the long bone of the thigh and the largest and strongest bone in the human anatomy. The proximal femur has large muscle attachments and a joint at the pelvis forming the hip. The distal femur also has large muscle-group attachments and forms the knee joint with the proximal tibia. The sites of fractures are often named in relation to the anatomy where the fracture occurs.

The femur has many common names and medical names which describe different portions of the bone. The femoral shaft is the diaphysis and is commonly fractured in trauma. The head of the femur is the proximal-most portion of the bone which directly joins to the pelvis forming the hip joint. The femoral neck is the region of bone joining the head to the femoral shaft. The greater and lesser trochanter are protuberances of bone on the proximal end of the femur, and each aid in defining the location of fractures. The distal femur has structures involved in the knee joint called condyles and epicondyles for muscle attachment.

Examining the anatomy of the injured limb should include all systems involved, including circulation, peripheral nerves, and motor function. Injuries often affect these non-boney structures due to the force causing the fracture or dislocation of the femur, also injuring surrounding anatomy. Absent or decreases in the circulation or sensation of the lower limb could direct care and should be carefully monitored before and after immobilization.[1][2]

Indications

Early diagnosis may not be feasible with non-displaced fractures or when it is unclear if there is a fracture or dislocation or both. In the pre-hospital setting, immobilization should be considered with obvious deformities, pain, swelling, and shortened limb and patients unwilling to use actively move the proximal lower extremity. Patients who hold the limb in a fixed position, such as shortened with internal or external rotation, or have other signs of injury should also be considered for immobilization. Often patients with femur fractures will have a significant decrease in pain by manual traction and subsequent traction splint placement.

In the hospital, dislocations should be reduced early, if possible. If the reduction is not successful or there are other life-threatening conditions which need treatment, immobilization is not necessary but is preferred to support the affected limb in a position of comfort until the patient can go to the operating room for definitive treatment.

The location of the fracture or the need to treat other more urgent and life-threatening injuries may direct the initial immobilization in the emergency department.[2]

Contraindications

There are few contraindications, primarily if the patient refuses a splint or other immobilization. Some splints are better suited for specific fractures, but if a fracture is suspected or diagnosed, using standard splinting guidelines has no absolute contraindications.

It may be difficult to place traction splints in the lower extremity multiple injuries, especially when ankle or other foot injuries make the straps impossible to attach or too uncomfortable. Certain situations like this may contraindicate some immobilization techniques, but with multiple options available, another option should be chosen.[3]

Equipment

At the most basic level, anything placed with adequate strength, size and length may be considered as an immobilization option. These should immobilize the hip and the knee as well to prevent movement and further injury. In a non-medical environment, these basic principles should guide the placement of an improvised device. 

There are multiple devices which may be used in immobilizing the femur. Pre-hospital providers often use commercial traction splints which have a rigid element with straps to attach to the patient and then apply traction using cords and tension devices. In the hospital, weighted traction splints may be placed on the patient. One of 2 methods creates this traction. The non-invasive method is to use a strap on the ankle and keeping the injured lower extremity straight weight is hung from the end of the bed typically using a frame and pulley system. Some fractures in the multiply injured patient may require transfemoral or transtibial pins to be placed which then allow skeletal traction. These pins are placed with careful sterile preparation and need specialized equipment typically found in orthopedic operating trays.[4][5][6]

Personnel

One person may place some splints, but traction splints require 2 or more people. One person should hold manual traction while the other person places the splint. Analgesia and sedation are needed to place transfemoral/transtibial skeletal traction pins, and this will require potentially other physicians, nursing support, and possibly respiratory therapy or other support staff where available.[7]

Preparation

Assembling all the appropriate equipment is often all that is needed and extra staff to hold the extremity and place the splint.

Extra preparation is needed if placing invasive pins for traction immobilization. The skin should be carefully cleaned using sterile technique. A sterile field should be created if possible, and analgesia and sedation should be administered.[7]

Document the neurovascular exam before any immobilization device is placed and any time the limb is manipulated, or the immobilization is changed to a different device.

Technique or Treatment

Most traction splints involve an ankle harness and some sort of cord or rigging to create the tension. Prior to placement, a neurovascular exam should be assessed to determine the patient's current baseline neurovascular status. Make a note of any abnormalities and make sure the placement of any splint does not further compromise to neurovascular status. Reevaluate the neurovascular states distal to the splint, or any device placed immediately after and with serial exams to ensure changes are promptly discovered and treated appropriately.

Each splint has specific directions for use but can often be deciphered by the need for securing the splint to the patient and the need for traction to be applied. There are 2 basic forms of this and many places the affected limb in the anatomic position, but there are some which use a flexed hip at 30 to 45 degrees and the knee flexed between 60 to 90 degrees.[2]

Complications

Improper placement of a splint may cause complications due to the straps or parts of the rigid structure of the splint causing local injuries. Once immobilization has been achieved, continually test distal circulation, sensation, and motor. Perform frequent interval reevaluation of the neurovascular status as changes often occur in the acute phase of the injury as swelling increases. Complications most commonly occur in relation to one of these areas.

Swelling may also cause local and distal complications, and the patient should be frequently evaluated for compartment syndrome.

Transfemoral/transtibial pins may have a localized infection or bleeding. Routine pin site care should address these to prevent these potential complications.[4][8]

Clinical Significance

Femur immobilization is a temporary measure to bridge to definitive care. The clinical significance of immobilization is stabilizing the original injury and preventing further injury. Femur fractures produce sharp shards of bone which may lacerate vessels and nerves which course along the shaft of the femur. There is also the potential for further injury to the same structures in dislocation injury. Health care teams should make every effort to prevent these injury complications as they may be life or limb threatening. Laceration of the femoral artery by a bone shard could lead to significant bleeding in the thigh and cause injury to the distal limb including ischemia and compartment syndrome.

From the patient perspective, proper immobilization often leads to significant pain reduction and reduced need for analgesics. The patient may also experience painful muscle spasms. Treat the muscle spasm to improve patient comfort and also reduce needed analgesics.

Enhancing Healthcare Team Outcomes

The team caring for patients with a femur injury requiring immobilization includes pre-hospital, emergency department, and inpatient teams. Each of these teams needs to reevaluate the need, placement, and effectiveness of the immobilization if placed by a previous team. Some immobilization devices and techniques may suit the needs of these teams, but change may be necessary according to the needs of a new team and environment. When transferring care, teams should include communication about the immobilization and any deficits observed before placing the immobilization device. Handoff is a source of significant risk in relation to patient harm if the appropriate information is not clearly communicated to the new team.[9][10] (Level V and III)

Each team is responsible for evaluating and reevaluating any device placed on a patient. When placing an external device on the lower extremity, an initial evaluation of circulation motor and neurologic is necessary. If a team member notices a deficiency or abnormality, this should be communicated immediately to the physician caring for the patient. This may indicate a critical condition, and the physician should direct care, which may be to adjust the immobilization device, ordering tests, or changing the timeline for definitive treatment. 

Other specialists may need to be involved based on the clinical findings. These cases often involve trauma surgery, vascular surgery, and neurosurgery or once another diagnosis has been discovered these specialists may become involved.