In a life-threatening medical emergency, there are vital signs that medical personnel monitor to assess the functioning of vital body organs. The four basic vital signs are body temperature, pulse rate, respiration rate, and blood pressure. Each of these vital signs have established norms for healthy proper functioning, as well as values indicative of when a medical problem is occurring or exists.
An Orthopedic Emergency
The musculoskeletal system consists of bones, joints, ligaments, tendons, and muscles. A musculoskeletal or orthopedic emergency can result when certain of these tissues become damaged to the point that they require immediate or at least timely medical treatment to avoid permanent loss of function.
A Fractured Bone
An obvious orthopedic/musculoskeletal emergency is a fractured bone, especially when the fractured edges of the bone break through the skin, known as an open or compound fracture. In these instances, there is a high risk of bone infection and constitutes an orthopedic emergency. An infected bone can impede blood circulation within the bone and potentially lead to bone tissue death. The infection, if left unchecked for too long, could potentially spread to a nearby joint, damaging its tissues and negatively impacting its functioning.
Further, if a fracture is such that it produces a severely mangled or misaligned limb, there is always the possibility of the damaged bones lacerating or compressing the blood vessels that feed the muscles and the nerves that innervate them. A disruption to the continuous oxygen carrying blood flow feeding these muscles, or more specifically the nerves that innervate them, can lead to the destruction of the nerve, and render the muscle useless in its inability to contract and apply the force for movement.
Anterior Compartment Syndrome – Disruption in the Blood Supply
A less obvious orthopedic/musculoskeletal emergency that can progress over time is a condition known as compartment syndrome. A classic example is the development of Anterior Compartment Syndrome after sustaining trauma to the anterior shin area of the lower leg. The mechanism of injury for this medical condition can result from trauma such as being kicked in the shin area during a soccer game or falling hard on the anterior area of the lower leg from a bike accident or literally any trauma that produces significant bleeding into the compartment area.
It is referred to as a compartment in that it has structures on all sides that are quite strong and thus limit the amount of expansion that could occur in the compartment. Posteriorly the compartment is bordered by the interosseous membrane that runs between the tibia and fibula bones. These bones form the lateral parts of the compartment, and the tough lower leg fascia forms the anterior border of the compartment.
Located within the anterior compartment are four muscles, the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and the fibularis/peroneus tertius. The deep peroneal nerve that innervates these muscles and the anterior tibial artery that supplies all these structures with oxygenated blood also run through the anterior compartment. If following a traumatic event there is excessive bleeding into the compartment it will cause an increase in the intra-compartment pressure. The muscles themselves can handle the rise in pressure, but unfortunately the anterior tibial artery (a tube structure) can become compressed shutting off blood and oxygen supply to the deep peroneal nerve and can constitute an orthopedic emergency. If the disruption in the blood supply lasts too long (peripheral nerves become unsalvageable when deprived of blood and oxygen after approximately 6 hours) the nerve will die, and the person will develop Drop Foot. A person with drop foot is unable to use the muscles that are in the anterior compartment leaving them unable to lift their foot upward toward their shin. Imagine how this would affect a person’s gait pattern.
The 5 P’s of Anterior Compartment Syndrome
Fortunately, this condition also presents with signs and symptoms that progress in a hierarchical pattern that can alert us to an impending orthopedic emergency. They are:
- Pallor (pale/white skin tone)
- Paresthesia (numbness, tingling sensation – lower leg and foot)
- Pulselessness (faint or absent pulse at the dorsalis pedis artery between the 1st and 2nd metatarsal bones)
- Paralysis (weakness or total absence ankle dorsiflexion)
When to Act
If you experience trauma and accompanying swelling to the anterior compartment of the lower leg you should diligently watch for these signs. Sure, pain upon impact is to be expected. However, persistent pain with your leg turning pallor or white is an indication that you are developing Anterior Compartment Syndrome and constitutes an orthopedic emergency, and you need to make a bee line to the hospital.
Lynn Perkes is a full-time faculty member at Brigham Young University-Idaho teaching courses in Kinesiology and Biomechanics, Applied Kinesiology and Assessment, Therapeutic Exercise, and other Physical Therapist Assistant classes. He writes part-time for ProhealthcareProducts.com, who sells healthcare, therapy, fitness, medical, and personal protective equipment.