Salter Harris Fracture

 

Salter-Harris fracture is a common injury in children that involves the growth plates. 15% of all fractures in children involves the growth plate, and it occurs more in boys than in girls. The growth plate injuries occur more distal than proximal, such as distal radius, distal tibia, and distal phalanges. Growth plate injuries in children are common in the bones of the lower (tibia and fibula). It is important to diagnose these fractures as they may affect the growth of the bone if not diagnosed and treated properly. There are generally five types of Salter-Harris fractures. The higher of the type number, the more complications associated with the fracture and worse prognosis. Growth plates produce the longitudinal growth bones. The reserve zone of the growth plate is the inactive zone. The proliferating zone of the growth plate has cellular proliferation and longitudinal growth, and this zone makes a person tall or short. The hypertrophic zone of the growth plate has maturation, degeneration, and provisional calcification. The majority of growth plate injuries occur in the hypertrophic zone. The hypertrophic zone is weak. In fact, the hypertrophic zone is weaker than the ligaments, and it provides a cleavage zone for the fracture to occur. Type I Salter-Harris fracture is difficult to diagnose; 5% of fractures are Type I. The fracture occurs through the growth plate, and there may not be an obvious displacement. Sometimes the diagnosis is a clinical one. Fracture occurs through the weak zone of provisional calcification. Type I is known by fast healing and rare complication rate. Type II is a fracture through the growth plate and the metaphysis, sparring the epiphysis. 75% of fractures are Type II. The corner of the metaphysis separates (Thurston-Holland Sign). With Type II, the fragment usually stays with the epiphysis while the rest of the metaphysis will displace. Healing is fast and growth is usually okay. Injury to the distal femur will cause a high rate of growth abnormality. Type III is a fracture through the growth plate and epiphysis, sparring the metaphysis. The fracture splits the epiphysis. 10% of the fractures are Type III. Fracture extends into the articular surface of the bone (intraarticular fracture). It requires anatomic reduction of the joint and internal fixation. An example of Type III is the Tillaux fracture of the distal tibia. CT scan may be needed to diagnose this fracture. Type IV fracture passes through the epiphysis, the growth plate, and the metaphysis; 10% of fractures are Type IV. It can cause complications such as growth disturbances and angular deformity. Type V is uncommon; about 5% are Type V. It is a compression or crush injury of the growth plate. There is no associated fractures of the epiphysis or metaphysis. Initial diagnosis may be difficult. Type V has the highest incidence of growth arrest and disturbance. Type I and Type II usually do not require surgery and will have a better prognosis than Type III, Type IV, and Type V. In Type I and Type II, the reduction of the fracture may not be anatomic. Despite this, the prognosis is usually good. In Type III and Type IV, the fracture is usually intraarticular and anatomic reduction is necessary. Type III and Type IV do not require surgery and the prognosis is usually fair. Type V is rare and has a poor prognosis. In general, the distal femur contributes to approximately 9-10mm of growth per year. The proximal tibia contributes to approximately 6mm of growth per year. Girls complete growth at the age of 14 years. Boys complete growth at the age of 16 years. In situations of child abuse, you may find growth plate injury or physeal separation as you can see in transepiphyseal separation of the distal humerus in children. 

Fracture Femur Hoffa Fracture

 

Hoffa fracture is a coronal split of the posterior condyle of the femur. Hoffa fracture is a rare intra-articular fracture of the posterior femoral condyle occurring from violent trauma, and generally occurs in young adults. Three types of Hoffa fractures are described. This classification is based on the location of the fracture within the condyle. Hoffa fracture can be an isolated fracture; however, it is often associated with other distal femur fractures. 38% of intra-articular distal femur fractures may have a Hoffa fracture (coronal plane fracture). The Hoffa fracture is a lot more common in open fractures than in closed fractures. Fracture may occur in either condyle, but the lateral condyle is the most common one to be affected by Hoffa fracture. It affects a single condyle in about 75% of the time, and the lateral condyle in about 85% of the time. Hoffa fracture occurs due to axial compression in a flexed knee. The mechanism of injury is controversial. The fracture is coronal, and it can be missed on routine lateral x-rays. The undisplaced fracture of the condyle may become displaced if the fracture is missed. The Hoffa fracture is almost like the capitellar fracture of the elbow. This fracture has the same story as the capitellar fracture, it is hidden, and you can miss it on the x-ray (you must look for it). CT scan is very helpful in the diagnosis of Hoffa fracture and will give you great details about the articular surface of the distal femur, especially if the fracture is comminuted. X-rays are not very good in diagnosing the Hoffa fracture. 20% of Hoffa fractures are diagnosed with x-rays only, so the CT scan is the best study for diagnosing the Hoffa fracture. Use a high degree of suspicion in the diagnosis of this fracture because the fracture may be subtle, and you may not be able to see it on routine x-rays. Treatment is reduction and stabilization of the fracture. stabilization of the fragment is usually done by headless compression screws and can be buried underneath the surface. Fixation can be done from either the anteroposterior (AP) direction or the posteroanterior (PA) direction. It can be temporarily fixed with k-wires. Permanent fixation is done with headless compression screws.