Diagnosis

Based on orthopedic exam results and radiographic findings, comminuted mid shaft 
(diaphyseal) femoral and tibial fractures with multiple fragments were apparent.   Both 
fractures can be classified as closed because no open wounds or skin defects were noted 
at either fracture site.

Fracture Healing
	There are several factors that contribute to fracture healing or possible 
complications.  Vascular disruption occurs in the event of bone fracture, and the severity 
can be estimated based on the location and type of fracture.  In the case of the diaphysis, 
the blood is supplied primarily by the principal nutrient artery (blood supply is not as rich 
as the metaphyseal region of the bone).  The diaphyseal fractures in this case will most 
assuredly have compromised blood supply, and therefore slower healing time and a 
greater likelihood of complications.
	Bone healing occurs in stages Ð primary and secondary bone healing.  During 
primary bone healing, osseous tissue formation begins under conditions of rigid fixation.  
Lamellar bone forms after granulation tissue or woven bone deposition.  This bone is 
mechanically inferior to normal cortical bone, and requires months for return to normal 
strength.  Radiographically, primary bone healing is characterized by a gradual loss in 
opacity of the fragment ends, a progressive disappearance of fracture lines, and re-
establishment of cortex and medullary continuity.
	Secondary bone healing involves fibrous connective tissue formation 
(fibrocartilaginous callus) that is eventually replaced by bone.  Stability of the fracture 
site favors the vascularization and the bridging of fragments by formed calluses.  Initial 
radiographic signs of callus formation (at two weeks) are irregular cortical margins and 
faint mineralization.  By four weeks, the fracture line is slowly obliterated and a bony 
callus bridges the fracture area.  After twelve weeks, the external callus will remodel until 
the continuity of the cortex and medullary cavity is re-established.