The Common Vein Copyright 2011
Introduction
The assessment of the associated injuries becomes the focus once the size shape and position of the fracture and fragments is complete.
Bones are related to the structures they connect to and structures they are in close proximity with. Knowledge of the ligaments, tendons and muscles associated with the fractured bone need to be evaluated clinically and if in question MRI is best suited to evaluate these soft tissues.
This X-ray on the antero-posterior (A-P) projection shows a simple displaced oblique fracture of the distal shaft of the fibula in a 36 year old male following blunt trauma. In image b the ankle is overlaid in purple and the area of interest is highlighted in black and white. There is significant, lateral displacement of the distal fragment so there is virtually no bone on bone alignment. This morphology is not conducive to satisfactory healing and likely would require open reduction. In addition to the fracture there has been significant damage to soft tissues and the mortise is not intact with medial displacement and subluxation of the tibia in relation to the talus suggesting rupture of at least the deltoid ligament. In image c the ankle is overlaid in teal blue and the subluxed tibia is highlighted in black and white. The mechanism of this injury is likely due to a an inversion injury of the ankle resulting in an oblique fracture of the fibula and subluxation of the tibia off the talus.
Courtesy Ashley Davidoff Copyright 2011 99854.6b01c01.8s
Arteries veins and nerves also have a close relationship with bone and thus injury with bleeding or pseudoaneurysm formation or spasm with distal compromise need to be evaluated clinically and radiologically.
The CTscan without contrast is from a 19 year old male who sustained head trauma and who is complaining of a severe headache. The scan shows a high density lenticular shaped hematoma (a,b,c),. The right parietal collection is an extradural or epidural hematoma, with the outer border conforming to the shape of the skull and lined by the bone) and the inner border lined by two layers of dura (green c,f) and the arachnoid (pink c,f). There are bubbles of air scattered along the inner bone surface (black bubbles best seen on the magnified views (c, f) a tiny fragment of bone (white arrow in f) but seen on images d, and e as a white speck. The fracture of the temporal bone is ringed in orange on the coronal reconstructions of the axial views (h,i)
Courtesy Ashley Davidoff MD Copyright 2010 98056c04.9s
In fractures of large long bones for example the femur or tibia fat can infiltrate the veins and embolize to the lungs causing fat embolism and pulmonary compromise. Thrombotic embolism is also a common subacute complication of fractures as a result of immobilization following a fracture.
The images are from a 21 year old college student and football player who sustained a transverse fractures of his right tibia and fibula. While awaiting surgery he became short of breath, tachypneic and tachycardic with his saturations dropping to the 70’s from 90’s on room air. He had a fever to 103, heart rate of 100, with a respiratory rate of 30 and a systolic pressure of 140. He required intubation for 5 days The plain films show fractures through the mid shaft which is the region of the medullary canal and where fat containing yellow resides in medullary cavity. The CTscan in c and d show ill defined fluffy nodules with ground glass changes and thickening of the interlobular septa at the lung bases. Centrilobular nodularity is suggested. The clinical presentation together with the location of the fractures and CT appearance suggest a diagnosis of fat embolism.
Courtesy Ashley Davidoff MD copyright 2009 all rights reserved 86255c.8s
Nerve injury is best diagnosed clinically. Burst fractures of the vertebral bodies can result in retropulsed fragments which impinge on the spinal cord and may cause significant morbidity. Similarly, pathological fractures of the vertebral bodies caused by metastatic disease can also impinge and compress on the spinal cord.
The Chance fracture
A Chance fracture is a flexion injury of the spine consisting of a compression injury to the anterior part of the vertebral body and a transverse fracture through the posterior elements caused by sudden forward flexion compressing the vertebral body. A distraction injury to the posterior elements results as well. This injury is commonly associated with an MVA where the patient was wearing only a lap seatbelt and deceleration by the force of the accident throws the patient forward and the lap belt acts as the imposing force causing the patient to flex violently.
Associated intraabdominal injuries include small bowel and large bowel contusions or lacerations, mesenteric contusions or lacerations, and pancreatic injuries.
The CT scan is from a 17 year old male who presents with back pain and abdominal pain following an MVA. He was wearing a lap seatbelt. Images a and b show a fracture through one of the lumbar vertebra (green arrow and highlighted in black and white in b) Images c and d through the pelvis reveal free fluid with a suggestion of a hematocrit level (maroon lower layer and straw colored supernatant in d). Image e and f demonstrate induration in the retroperitoneal fat around the descending colon (red arrows in f) At surgery hemoperitoneum and colonic injury was identified. This fracture is known as a Chance fracture and has a known association with high impact MVA’s where the patient wearing a seatbelt is subjected to violent hyper flexion causing s compression fracture of the vertebral body, distraction fracture of the posterior elements commonly associated with pancreatic, bowel, or mesenteric injuries.
Courtesy Ashley Davidoff Copyright 2011 43300c05.8
Fractures of ribs near the lung, spleen or liver can result in complicating penetrating injuries of any of the soft tissue organs with potentially significant and life threatening complications.
The CT scan shows a posterior rib fracture that impinges minimally on the spleen. This patient was discharged from the hospital following a motor vehicle accident with a discharge diagnosis of a rib fracture. He re-presented with splenic rupture and hypotensive probably caused by penetration of the spleen by the fracture fragment. He required splenectomy
Courtesy Ashley Davidoff MD 20803b
The most common associated injuries of fractures are those that involve the ligaments tendons and muscle, though those that have the greatest morbidity with life threatening potentials occur when the surrounding vessels or organs are affected. The most serious of these are head injuries and spinal injuries.
References
Chance GQ: “Note on a flexion fracture of the spine.” Br J Radiol 1948; 21: 452-3.
Malagari K, Economopoulos N, Stoupis C, Daniil Z, Papiris S, Müller NL, Kelekis D. High-resolution CT findings in mild pulmonary fat embolism. Chest 123(4):1196-201 2003.
Wheeless Wheeless’ Textbook of Orthopedics