Maletzky (1993) found that, of his sample of 4,402 convicted child sex offenders, 0.4% were female.According to research conducted in Australia by Kelly Richards on child sexual abuse, 35.1% of female victims were abused by another male relative and 16.4% of male victims were abused by another male relatives. Male relatives were found to be the most relevant predators in the case of both gender.In U.S. schools, educators who offend range in age from "21 to 75 years old, with an average age of 28".According to C.E. Dettmeijer-Vermeulen, Dutch national spokeswoman on human traffic and sexual violence against children, in the Netherlands, 3% of the convicted perpetrators are women, 14.58% of the victims are boys and "most victims were abused by a family member, friend or acquaintance." One in six perpetrators are underage. Typology
Early research in the 1970s and 1980s began to classify offenders based on their motivations and traits. Groth and Birnbaum (1978) categorized child sexual offenders into two groups, "fixated" and "regressed". Fixated were described as having a primary attraction to children, whereas regressed had largely maintained relationships with other adults, and were even married. This study also showed that adult sexual orientation was not related to the sex of the victim targeted, e.g. men who molested boys often had adult relationships with women.Later work (Holmes and Holmes, 2002) expanded on the types of offenders and their psychological profiles. They are divided as follows:
Situational – does not prefer children, but offend under certain conditions.
The Monteggia fracture is a fracture of the proximal third of the ulna with dislocation of the proximal head of the radius. It is named after Giovanni Battista Monteggia. Causes
Mechanisms include:

Fall outstretched hand with the forearm in excessive pronation (hyper-pronation injury). The ulna fractures in the proximal one-third of the shaft due to extreme dislocation. Depending on the impact and forces applied in each direction, degree of energy absorption determines pattern, involvement of the radial head and whether or not open soft tissue occurs. Direct blow on back of upper forearm would be a very uncommon cause. In this context, isolated ulnar shaft fractures are most commonly seen in defence against blunt trauma (e.g. nightstick injury). Such an isolated ulnar shaft fracture is not a Monteggia fracture. It is called a nightstick fracture. Diagnosis
Classification
There are four types (depending upon displacement of the radial head):

I - Extension type (60%) - ulna shaft angulates anteriorly (extends) and radial head dislocates anteriorly. II - Flexion type (15%) - ulna shaft angulates posteriorly (flexes) and radial head dislocates posteriorly. III - Lateral type (20%) - ulna shaft angulates laterally (bent to outside) and radial head dislocates to the side. IV - Combined type (5%) - ulna shaft and radial shaft are both fractured and radial head is dislocated, typically anteriorly.These are known as the Bado types.