A Sydney teenager remains in an induced coma after a metal pole became embedded in his head during a birthday party fight, with police appealing for information about the brawl.

Liam Knight, 17, was struck by a 2.5 metre pole thrown by a gatecrasher at an 18th party in Forestville on Friday night.

The incident followed a series of altercations sparked when a pair of males were refused entry to the house party on Keldie St, police said.

After an initial skirmish, the gatecrashers jumped a rear fence in an attempt to gain entry before one of them began throwing metal bars towards the partygoers.


One struck Mr Knight on the right side of his head and became embedded.

Emergency services rushed him to Royal North Shore Hospital where the pole was surgically removed.

He remains in an induced coma with serious head injuries.

Police have spoken to a number of witnesses but are appealing for other partygoers to contact them.