A family's quest for an investigation into their grandmother's death has been reignited by a Canberra court decision.
Justice John Burns has granted the family of Lima Ray Thatcher leave to appeal from a 2013 decision to disallow them from amending their case.
Mrs Thatcher, a dementia sufferer, fractured the neck of her right femur after a fall at her Yass nursing home in February 2011.
She was taken to The Canberra Hospital for surgery, but doctors accidentally conducted replacement surgery on the wrong hip after a form had been incorrectly filled out.
When the error was discovered, doctors kept her under anaesthetic and replaced the correct hip in a lengthy 3½-hour procedure.
The 86-year-old's post-operative condition deteriorated and she died 10 days after her hospital admission.
An autopsy found Mrs Thatcher had died of heart disease.
Coroner Peter Dingwall declined to conduct a hearing into the death, finding it had been unnecessary as the manner and cause of death had been clear.
But the family applied to the ACT Supreme Court to order the coroner to hold a hearing and force the ACT government to launch an independent inquiry to probe the death.
Mrs Thatcher's granddaughters, Kate and Holly Chaloner, applied to the court to declare that their grandmother's rights had been breached and that she was subjected to medical treatment without her consent.
But, in April last year, orders were made, with the consent of the ACT, the set aside Master David Harper's orders.
But Master Harper's orders denying the Chaloner's application to amend their claim remained in force.
The government opposed the family's application for leave to appeal out of time, on the basis that any appeal would be bound to fail, and the grant of leave would be futile.
But Justice Burns disagreed and granted the application, saying the family had reasonable prospects of success to force a coronial hearing.
But he wrote that the Chaloner's could not succeed in its inquiry bid.
The judge found an administrative error meant the application forms had been lodged only four days past the deadline.
"I am satisfied that an acceptable explanation for the delay has been established," Justice Burns wrote in his decision.
"There is no suggestion that the respondent has suffered any prejudice by this delay."
"The applicants will be granted leave to appeal from the decision of the Master refusing leave to amend their pleading, but not including the proposed amendments seeking relief under the Inquiries Act."