Following the terrorist attacks of September 11, 2001, the United States waged the "war on terror," a continued combat campaign that has lasted more than a decade. Thousands of Americans have been killed and almost 50,000 troops have been wounded in the wars waged in Iraq and Afghanistan.

Perhaps the most lethal uses of force by insurgents have been improvised explosive devices. Blast injuries from these bombs including the loss of limbs, traumatic brain injury, and severe burns are prolific among wounded troops.

But service members are surviving these extreme injuries that would have proved fatal decades earlier. A warrior wounded in battle now has a 50% better chance of surviving than in any previous war, according to the Defense Department, which credits some of this advancement with improved body armor, better doctor and medic training, and an efficient and timely evacuation system.

Just like in preceding wars, medical research has churned out advancements to better heal the wounded and prevent more from dying on the battlefield.

Here's a look at some of the advances:

Traumatic Brain Injury

The Defense Department has documented almost 250,000 cases of Traumatic Brain Injury (TBI) since the year 2000, according to Defense Department spokeswoman Cynthia Smith. More than 60 TBI programs have been created at military medical treatment facilities at U.S. bases, and 11 new concussion restoration/care centers have been set up in deployed zones.

Before the wars in Iraq and Afghanistan, most attention was paid to severe traumatic brain injury, but with 95% of TBIs being mild in nature the research has changed its focus, according to Cmdr. John Hughes a Naval research neurologist.

"If you read a textbook 5 or 10 years ago on traumatic brain injury it was focused on more severe problems," said Hughes. "What we realized is that mild injuries are actually serious issues that we need to address."

To better understand the impact of these injuries more sophisticated techniques using MRIs have been developed that show the structural changes that take place in the brain.

Progress has also been made on early diagnosis of mild TBIs.

"The challenge really has been how do we diagnose these individuals," said Hughes. "How do we diagnose them as early as possible."

The military has taken steps to modify high-tech instruments used in hospitals and labs, making them portable units that can be used by medical personnel who are in the combat setting.

One example: a hand-held device called DANA (Defense Automated Neurobehavioral Assessment) that can be used to identify a concussion in the combat zone through a series of neurocognitive tests.

Prosthetics

Some 1,400 service members have lost one or more of their limbs, according to the most recent numbers released by the Pentagon.

Limb-loss injuries that would have once been fatal are now not only survivable, but some wounded service members are even returning back to the combat zone. Their prosthetic limbs however weren't quite cutting it.

"Walking through trails in the mountain ranges of Afghanistan are much different than walking on a street downtown," said Col. Paul Pasquina, chief of the Department of Orthopaedics and Rehabilitation at Walter Reed National Military Medical Center. "We noticed that some of these prosthetic limbs were breaking."

Pasquina said that in the past decade not only have prosthetics been made more rugged, but now they're motorized. Powered knees and ankles make it easier to change walking and running speed, helping the wounded walk more naturally.

Sensors are also being developed including implantable brain devices to allow for better control of prosthetic arms. For example, if you think about opening your hand the implantable device would turn that intention into an electrical signal to the prosthetic arm, causing it to open your hand.

Regenerative Medicine

Regenerative medicine uses strategies to replace deficits in nerves, blood vessels, for complex wound coverage and for bone regeneration to salvage limbs. Something as common as skin grafts, to something as obscure as regenerating an ear, are examples of regenerative medicine.

The Defense Department established the Armed Forces Institute of Regenerative Medicine (AFIRM) in 2008 to fund projects to restore the function of damaged tissues and organs. By 2011 more than 80 projects have been funded by AFIRM

One of those projects: spray on skin. Researchers are exploring ways to replace the old-fashioned method of skin grafts by taking a tiny biopsy of skin, breaking down the cells, putting those cells in an aerosol container and then spraying it on a burn site, according to Capt. Eric Elster, an organ transplant surgeon with the Walter Reed National Military Medical Center.

Hand and face transplants are also less risky for surgeons to perform now that the anti-rejection medication is safer.