Early acute fat embolism syndrome caused by femoral fracture: A case report

BACKGROUND Fat embolism syndrome(FES)is a rare complication caused by the presence of fat particles in the microcirculation,which usually occurs within 12-72 h after trauma.At present,there have been few cases of fat embolism presenting within 3 h after trauma.Here,we report a case of femoral fracture complicated with an acute fat embolism caused by a car accident.CASE SUMMARY A 29-year-old woman with pain,swelling and limited movement of her left lower limb after a car accident was taken by ambulance to our hospital.X-ray examination showed fracture of the middle and lower part of the left femur and fracture of the base of the left fifth metatarsal bone.She was hospitalized and admitted to the orthopedic ward.After the attending doctor performed tibial tubercle bone traction,the patient became confused,followed by respiratory distress.Finally,she was transferred to the intensive care unit.After nearly a month of treatment in the intensive care unit,the patient's cognitive function gradually recovered over 6 mo.CONCLUSION For patients with early traumatic fractures,young emergency physicians and orthopedics should be aware of the possibility of FES.

Postoperative complications of concomitant fat embolism syndrome, pulmonary embolism and tympanic membrane perforation after tibiofibular fracture: A case report

BACKGROUND Fat embolism syndrome(FES)is a rare disease characterized by pulmonary distress,neurologic symptoms,and petechial rash and seriously threatens human life and health.It is still neglected clinically because of the lack of verifiable diagnostic criteria and atypical clinical symptoms.No studies on FES with pulmonary embolism(PE)and tympanic membrane perforation have been reported to date.Here,we report a rare case of concomitant FES,PE and tympanic membrane perforation after surgery in a patient with a tibiofibular fracture.CASE SUMMARY A 39-year-old man presented with right lower extremity pain due to a car accident while driving a motorbike on the road.X-ray and computed tomography scans revealed a fracture of the right mid-shaft tibia and proximal fibula categorized as a type A2 fracture according to the AO classification.A successful minimally invasive operation was performed 3 d after the injury.Postoperatively,the patient developed sudden symptoms of respiratory distress and hearing loss.Early diagnosis was made,and supportive treatments were used at the early stage of FES.Seven days after surgery,he presented a clear recovery from respiratory symptoms.The outcome of fracture healing was excellent,and his hearing of the left ear was mildly impaired at the last follow-up of 4 mo.CONCLUSION Concomitant FES,PE and tympanic membrane perforation are very rare but represent potentially fatal complications of trauma or orthopedic surgery and present with predominantly pulmonary symptoms.Early diagnosis and treatment can reduce the mortality of FES,and prevention is better than a cure.

Simultaneous bilateral floating knee:A case report

BACKGROUND The phrase “floating knee is a flail knee joint,” referring to ipsilateral femoral and tibial fractures,was first used by Blake and Mc Bryde in 1975.This condition is often caused by a high-energy trauma with often extensive injury to the soft tissues,and is accompanied by life-threatening systemic complications,including head,chest or abdominal injuries and a high incidence of fat embolism.Floating knee is a severe and uncommon injury pattern.CASE SUMMARY A 27-year-old man sustained multiple injuries when the electric motorcycle he was riding was hit by a van.His injuries included traumatic hypovolemic shock,comminuted and open type II fractures of the left femoral shaft,fracture of the right femoral shaft,comminuted fracture of the bilateral tibial and fibular shaft,and multiple lacerations and abrasions on his forehead,lower lip,neck and limbs.The diagnosis was simultaneous bilateral floating knee complicated with soft tissue injuries.After emergency treatment and the exclusion of life-threating complications,open reduction and internal fixation were successfully performed using plates and screws in the bilateral femoral and tibial shafts.CONCLUSION Simultaneous bilateral floating knee is a rare and severe injury pattern.The treatment is challenging,and complications.We present a case report of a young adult who suffered from bilateral floating knees during road traffic accident.We also offer our treatment experience of this complex injury and review past literature.

EXPERIMENTAL STUDY OF FAT EMBOLISM SYNDROME

To find the diagnostic methods for snbclinical stage fat embolism syndrome (FES), we established an experimental animal model, using fat intravenous injection. The fat was obtained from the long bone marrow cavity of homologous dogs. Fourteen healthy mongrel dogs received 0.7 ml / kg fluid marrow fat injection and all of them developed FES within 48 hours. The blood samples collected from the pulmonary vessels by floating catheter and peripheral vein at different time intervals were subjected to blood gas analysis and were frozen sectioned rapidly. The sections were stained with oil red 'O'. Positive result was seen 2 hours after fat injection in both pulmonary and peripheral blood. Computer image analysis showed that the number and diameter of fat droplets in pulmonary vascular blood were obviously higher and larger than those in peripheral vein blood. These findings were correlated well with blood gas changes and clinical features. The demonstration of fat droplets from pulmonary or peripheral blood by oil red 'O' staining combined with blood gas changes (PaO2<7.99 kPa, P(A-a)O2 > 6.09 kPa) may be rapid and specific for early diagnosis of FES. In the treatment of FES, dexamethason can stabilize the cellular membranes and inhibit the neutrophil response to fatty acid and the release of phospholipase A2, arachidonic acid and platelet aggregation.