This horrific injury was suffered by a uniformed garda when he was grappled to the ground while trying to arrest a suspect.
The garda received 22 staples in the elbow wound and was off work for five months.
The photograph of the injury was displayed today during a debate on assaults on members of the force at the annual conference of the Garda Representative Association (GRA) in Galway.
Later, Garda Commissioner Noirin O'Sullivan revealed how she was attacked and spat on while on duty.
Ms O'Sullivan recalled how she had her shoulder dislocated on Dublin's Parnell Street and can now "empathise" with assault victims.
"I am very conscious of assaults on our members. It's something that resonates with me every time I hear it," she said.
"I've been bitten, I've been spat at, I've been assaulted. I know what it's like to wait at home when you have a family member assaulted and you are waiting to see have they recovered from a very serious injury."
She recalled how she spoke to a victims group in the Rotunda Hospital about her attack.
"I recounted a story about being assaulted on Parnell Street and ending up with a dislocated shoulder, so I know exactly what it means to go through assaults," Ms O'Sullivan said.
"I know what it takes to have the courage to come out after being assaulted, after being called names, after being videoed.
"So, I can empathise with every one of our members who go out every day to do a good job.
"I can empathise hugely with their families to see do they come home safely. I know what that feels like."
Kilkenny delegate Ger Comerford produced the photograph of his unnamed colleague, who was assaulted in 2013.
Earlier, Mr Comerford said the garda suffered shattered cartilage in his elbow after hitting the pavement when he was pulled down by the suspect trying to evade arrest.
The suspect was later convicted of a charge of assault causing harm.
The GRA wants legislation to create a specific charge of assault on a garda, or any other frontline emergency worker, with a minimum mandatory sentence of at least a year.
Central executive member James Morrisroe, of Cavan-Monaghan division, said they were not trying to "tie the hands" of the judiciary but believed that an assault on a garda should carry a jail sentence on conviction.
He said he had been assaulted five or six times during his 21 years in the force.
He also called for other deterrents and said that, while Ms O'Sullivan had suggested the force was 10 years behind with the latest technological aids, he believed the time lag was more like 30 years.
Donegal delegate Louis Browne told the conference that he had served nine months with a United Nations peacekeeping force in Bosnia in 2002, when the country was torn apart by internal strife, but he had not faced any assaults.
Mr Browne then said he had suffered two serious assaults while on duty. In one incident he received a badly gashed head, and also had to get 11 stitches for injuries to his fingers in another attack.