In 2003 special education teacher David Arnold moved to the Northern Territory from Kyabram in Victoria.
He arrived in the Northern Territory full of idealism.
"Like everybody else, you look at what your next step is going to be. And, like most teachers, you think you are going to save the world," Mr Arnold said.
"I moved to the Northern Territory thinking I was going to turn things around for the indigenous school kids"."I wanted to help indigenous students," he said.
"But it wasn't until I got here that I realised the size of the problem.
In 2005, while working at Katherine High School, David Arnold was made Teacher of the Year.
But in 2008 Mr Arnold was brutally attacked at work.
"It was one isolated incident on April 7 2008 at 7.15am that changed my life," he said.
Mr Arnold was working in his classroom when a group of students entered the room.
Mr Arnold tried to confiscate mobile phones from three boys aged 13 and 14.
His left leg was stomped on by the boys.
One boy slammed him in the chest, knocking him to the ground and another boy then jumped from a table on to his leg.
Mr Arnold was found on the classroom floor by a fellow teacher.
He was medivaced to the Epworth Hospital in Melbourne.
In 2012 on-going infections meant Mr Arnold's leg had to be amputated from the knee down.
Media reports at the time of his amputation claimed Mr Arnold had received minimal assistance from the department "because the school did not report the incident to the police at the time".
An artificial leg had been fitted and Mr Arnold was walking for 70 minutes twice a day.
"I'm getting used to it," Mr Arnold said.
Mr Arnold had endured 10 operations, including three knee replacements, since being assaulted by the three teenagers in 2008.
"It all happened so quickly."
Mr Arnold wanted to return to teaching.
"I'd like to think that I could go back and serve some meaningful purpose," he said.
By January 2015 Mr Arnold, now 66 and living in Victoria, had undergone 12 rounds of surgery.
A faulty prosthesis had caused additional damage to his leg and so Mr Arnold had been wheelchair-bound for the past 15 months.
"I haven't been able to do anything," he said.
So Mr Arnold had decided to undergo one more operation.
He said this was his "last throw of the dice" to walk again.
"If it doesn't work it means I will be restricted to this bloody wheelchair for the rest of my life," he said.
"It has to work".
Mr Arnold said he wanted to return to teaching.
"I've been extremely restricted and I just want to get out of this bloody chair and have the opportunity to get back on with my life," he said.
"I haven't come to accept it, but I've come to the conclusion that if you dwell on these things, its not going to help you" he said.
Doctors have told Mr Arnold that if the operation is a success, he could be walking with a prosthetic leg within six or seven months.
Mr Arnold has launched legal action so he can afford his on-going medical costs.
Mr Arnold's solicitor, Leeha James, told the NT NEWS the latest court proceedings were so Mr Arnold could "access certain rehabilitation benefits that have ceased"
Catherine Weber from the Department of Education said Mr Arnold was "disputing some changes to his entitlements" under the Workers Rehabilitation and Compensation Act.
She denied reports the department had not assisted the Territory teacher.
"Mr Arnold has been fully supported by the school and department since the incident," she said.
"Mr Arnold has received entitlements under the Act as determined by TIO, which has included weekly payments, ongoing medical treatment, rehabilitation and household and travel assistance".
Former Northern Territory teacher who lost leg in student attack is launching legal action, Shae McDonald, NT News, 17 January 2015
.After school attack, it's a step at a time for teacher who lost a leg , Lucie van den Berg, Herald Sun, 10 December 2012
Teacher learns to walk after attack, Nigel Adlam, NT News, 11 December 2012