He spent time in hospital, with all his family round his bedside - but did one of them do the deed?
There were seven suspects and after months of wrong guesses and misleading storylines, we eventually found out who did it.
Adam Barlow (Sam Robertson), Ken's grandson seemed the most likely candidate. He was exiled from the family when Ken discovered he was involved in dealing drugs. Ken even threw a whole stash of dodgy money into a fire in the garden .
The loss of the money caused Adam to be assaulted by thugs who wanted their cash back.
At the time of Ken's attack Adam had lied to everyone he was in Canada, but actually he was back in town and skulking around in the shadows, aided by his cousin, Amy Barlow.
In addition to all of this, Adam's fingerprints were discovered on the new kitchen worktops that were fitted the night of Ken's attack. When Amy reported this to the police, Adam was promptly arrested and charged with the attempted murder of his grandfather.
Amy herself then also became a suspect, even though she wasn't initially on the suspects' line-up list (we all know that doesn't mean anything in Soapland!)
On the night of the attack, she was due to perform at a violin concert, but refused to take part and went missing. Ken had said he wasn't going to watch her play after she accused him of favouring Simon Barlow over her. She also overheard her grandad saying he wished he'd never married her late-grandma, Deirdre Barlow.
Tracy Barlow, Amy's mother, overheard the same comment and was upset and furious in equal measure. Coupled with the fact Tracy had recently asked Ken to help her buy the florist shop and he refused, but instead considered helping Peter Barlow buy the Rovers Return, Tracy was feeling second best.
The night of the attack, Tracy went missing and her then-boyfriend Luke gave her a false alibi. She was actually sneaking round helping on-the-run former boyfriend Rob Donovan stay hidden from the police.
But when it was later discovered Tracy had been cut out of Ken's will, it gave her a very real motive for lashing out in anger.Tracy was even arrested after confessing she had tried to kill Ken, but she was just owning up as she thought Amy was the culprit and soon retracted her confession
Meanwhile, Ken's eldest son, Peter, was fuming with his dad after Ken had wrongly assumed Peter was having an affair with Chloe Tipton and told Peter's girlfriend, Toyah Battersby, as much.
Peter was almost driven back to drink and decided his father was at the root of all his problems, telling Ken he was dead to him. Peter did leave his father a voicemail that night apologising, but he didn't say what he was sorry for and when Simon listened to it, he thought his dad might be guilty.
Pat Phelan, the local builder, and later Street serial killer, was fitting a new kitchen for Ken at the time of the attack.
But he was taking his sweet time and Ken was getting impatient, lashing out at Phelan for conning him like he did everyone else with his property scam. Everyone knows you don't lash out at Pat Phelan...
The baldy builder was later found by Daniel Osbourne at the scene of the attack standing over Ken's body. Phelan was arrested, but released.
Daniel's girlfriend, Sinead Tinker, had recently had an abortion after Ken had told her if she had the baby she'd be ruining Daniel's promising future. She'd lied to Daniel that she'd lost their child, but on the night of Ken's attack she was forced to tell Daniel the truth.
Daniel dumped her and she drunkenly went to see Ken, banging on his door, wanting to confront him.Sinead was arrested when Adam's digging pointed the finger well and truly at her, but we all know she didn't do it.
Daniel himself was devastated when he discovered the truth about Sinead's termination and blamed his father and his pushy attitude for the loss of his baby.
It was eventually revealed on May 26, 2017 that Daniel was responsible for pushing his father down the stairs.
Viewers saw Daniel retrieve the heavy-bound book that he used to hit Ken over the head sending him flying down the stairs, from under the floorboards and knew it was him, even though Daniel had watched Adam be arrested and done nothing.
Ken found out his son had tried to do away with him when they were at Daniel's old flat decorating it.
After discovering a box of Denise Obsbourne's old belongings, Ken started to wonder why Daniel was so desperate to not disturb a rose bush in the garden - and thought Daniel had killed his mum and buried her there.
It turned out Denise was alive and well, but as Daniel had a complete meltdown, Ken realised Daniel was the one who pushed him and Daniel confirmed it as he totally lost it.
Ken eventually talked his son round, and decided not to report him to the police, instead telling officer in charge DS MacKinnon that he now remembered tripping and falling down the stairs.
Daniel however gave a full confession, but as he was under psychiatric assessment at the time, MacKinnon decided to believe Ken's version of events.
Adam Barlow was released and the whole family disowned Daniel.
That's largely been forgotten now and everyone's playing happy families again, rallying round Daniel as he supports now-wife Sinead through her cancer and pregnancy.