A 20-year-old woman presented to the ED complaining of severe numbness, tingling, and pain in her left calf. According to the patient, she had attended a New Year’s Eve party, where she spent much of the time dancing. She was awakened by calf pain on the following morning and sought treatment at the ED.
On physical examination, the patient’s vital signs were normal. Examination of the left calf revealed tenderness to palpation; no swelling was noted. The patient was unable to lift her left foot or bear weight on the left leg. She had normal dorsalis pedis and posterior tibial pulses in the affected leg. The remainder of her examination was normal and no testing was performed. The patient was diagnosed with “floppy foot syndrome” and discharged home with a prescription for a nonsteroidal anti-inflammatory drug.
The next day, the patient presented to a different ED because of worsening pain and swelling of the calf. She was admitted to the hospital and the orthopedic service was consulted. The patient was diagnosed with compartment syndrome; however, by that time her condition was complicated by rhabdomyolysis, resulting in acute renal failure.
The patient underwent a fasciotomy. After surgery, she required hemodialysis until her kidney function returned. She had damage to the nerves in her left calf and leg resulting in a permanent foot drop that required prolonged physical therapy following her hospitalization.
The patient sued the initial EP for failure to diagnose compartment syndrome, which resulted in permanent nerve damage and foot drop. A $750,000 settlement was reached.
The EP did not appear to have taken this case seriously, as “floppy foot syndrome” is not a recognized diagnosis. No significance was attached to the presence of the foot drop, which is an objective and concerning physical finding.
The differential diagnoses of foot drop are relatively small: a nerve injury, which is the most common cause; a central nervous system event, such as a stroke; or a muscular disorder.3 An injury or problem with the peroneal nerve is the most common cause of foot drop.
While the patient’s history was not typical for the development of compartment syndrome, she potentially participated in strenuous physical activity, which can result in muscle swelling and subsequent compartment syndrome.4 The pain from compartment syndrome is typically described as out of proportion to physical findings; this seems to have been the case for this patient.
The symptoms and findings of compartment syndrome are classically taught as the five “Ps”: pain, paresthesias, paralysis, pallor, and pulselessness, with the symptoms typically presenting in this order. The patient had the first three symptoms, but they were not appreciated in the initial evaluation. Pulselessness is usually the last finding to develop, and tissue damage is frequently present at that point.
Interestingly, approximately 40% of compartment syndromes occur at the level of the tibia and fibula. The lower leg has four compartments: the anterior, which contains the anterior tibial artery and deep peroneal nerve; the lateral, which contains the superficial peroneal nerve; the superficial posterior, which contains the sural nerve; and the deep posterior, which contains the posterior tibial artery and nerve.
As pressure within the enclosed space increases due to swelling, hemorrhage, fracture, etc, the blood supply as well as nerve and muscle functions become compromised. Left untreated, the increased pressure can result in permanent tissue and nerve damage.
Compartment syndrome is a time sensitive diagnosis because of the need for surgical intervention to open the compartment. The EP can measure compartment pressures if he or she has the right equipment and training. A normal compartment pressure is less than 10 mm Hg. When the compartment pressure begins to exceed 30 mm Hg, tissue damage can occur. If unable to measure compartment pressure, an emergent orthopedic consult is indicated.