Q: Our 12-year-old daughter was thrown from her horse and then stepped on by the horse. She has a Torode IV pelvic fracture. We saw the X-rays so have an idea of what it looks like (very nasty). What does the Torode IV mean?

A: Pelvic fractures in children are classified according to severity based on X-rays. Two orthopedic surgeons by the names of Torode and Zeig first introduced this method back in 1985. Since that time, it has become a standard method of determining treatment.

According to this scheme (now just referred to as the Torode classification), there are four grades (or severities) of pelvic fractures. The grades include I, II, III, and IV based on location and amount of bone disruption.

As you might guess, Type I are the least serious injuries and Type IV the most serious. Type IV fractures are considered unstable and include disruption of the pelvic anatomy, hip dislocations, and/or more than one fracture affecting the pelvis and hip.

More recently, surgeons at Children's Hospital in Boston (associated with Harvard Medical School) have added one modification to this model. They have introduced two subgroups of the Type III fractures (Type IIIA and Type IIIB).

The modified groups (Type IIIA and Type IIIB) help to identify fractures that are more like Type II (labeled Type IIIA) or more like Type IV (labeled Type IIIB). This distinction is helpful because it tells the surgeon that children with Type IIIB are more serious, more likely to need a blood transfusion, and more likely to need a longer hospital stay.

Torode I and II pelvic fractures are avulsion (piece of bone breaks off) somewhere along the pelvic crest. With a Type I fracture, a separation occurs in the growth plate, which is still cartilaginous. Type I is much smaller in size than Type II.

Type III fractures affect the lower portion of the pelvis that bear our weight when we sit down. The symphysis pubis (where the two pelvic bones meet in the front of the body) may be involved. This part of the pelvis helps form a bony ring and pelvic "bowl" that support the bladder. The new Type III A/B designation gives an A if just the front or anterior portion of the ring is broken. Type IIIB indicates both the front (anterior) and back (posterior) portions of the ring are fractured.

A Type IV fracture has multiple different pelvic fracture locations. All involve complete disruption of the bone, nearby joints, and/or the hip (dislocation). Once you have the specific classification your daughter has been diagnosed with, then you will have a better understanding of how involved the pelvis is and the severity of the fracture(s).

Reference: Benjamin J. Shore, MD, FRCSC, et al. Pediatric Pelvic Fracture: A Modification of a Preexisting Classification. In Journal of Pediatric Orthopaedics. March 2012. Vol. 32. No. 2. Pp. 162-168.