In June, 17 men were sentenced for the sexual abuse of the vulnerable girl, which started when she was 12.
A serious case review found that between 2009 and 2011 opportunities were missed because there was not an "effective system" in place.
The report said services in the area had improved due to the case.
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Both West Yorkshire Police and Calderdale Council have apologised to the girl.
The Local Safeguarding Children Board's report said police and social workers were "unable to protect [her] because professionals in Calderdale did not, at that time, have an effective system for assessing and planning intervention for children at risk from sexual exploitation."
Det Supt Darren Minton praised the girl's "immense courage and bravery" in giving evidence against the men.
He said:  "West Yorkshire Police accepts that opportunities were missed in the past to protect victims of child sexual exploitation, it is important to stress that child sexual exploitation is a top priority and we now have strong partnerships and better working practices with agencies."
Police and social workers failed to protect a child from systematic sexual abuse by a group of men, a report into a case in Halifax has found.