Our not-so-healthy fascination with Britney Spears started during the great teen-pop explosion of 1999, when she first emerged as the Lolita of the Mickey Mouse Club. We sent her to the top of the pop charts. Our obsession peaked in 2007 when those heights became too much, and Spears went through The Meltdown By Which All Other Celebrity Meltdowns Shall Be Judged. We sent her to rehab.

Now, with her seventh album, “Femme Fatale,” it’s time to send Brit to Vegas.

Overflowing with sparkly, sexed-up dance floor razzle-
dazzle, these 12 songs would sound perfect in Sin City, that great show-biz retirement home where Spears could elegantly vanish from the paparazzi and the greater pop discourse. Yes, “Femme Fatale” is relentlessly entertaining, but Spears has nothing to do with its charms, somehow sounding more anonymous than she did on her 2008 comeback album, “Circus.” It might mark the biggest turning point in her career, driving a stake in the fleeting idea that Spears would one day bloom into an actual artist — one with something quasi-meaningful to say about her life, her career, her fame, her struggles, her favorite “Simpsons” episode, anything.

Instead, the 29-year-old manages to vanish completely from her own album — her vapid lyrical come-ons heavily Auto-Tuned and littered across a handful of exquisite dance tracks built by super-producers Max Martin and Lukasz “Dr. Luke” Gott­wald.

They work wonders on “Till the World Ends,” the most potent in the pile, a song about dancing through the apocalypse with a beat so cardio-riffic, you can count on hearing it until judgment day — or when your gym membership expires. Its refrain is sung not by Spears, but by a choir of phantom robots: “Oh-oh-oh-oh-oh-oh-oh!”

The rest of “Femme Fatale” is just as brainless, setting a litany of dopey pick-up lines to similar speaker-thumping sounds — pulsing Euro-house and dubstep, the strand of British dance music defined by woozy bass lines that can feel both disorienting and exhilarating.

Wait! Fame is both disorienting and exhilarating, right? But instead of singing about herself, Spears fills her lyric sheet with flirty nightclub prattle. “You feel like paradise, and I need a vacation tonight,” she sings on “Hold It Against Me,” before the song dive-bombs into a surging dubstep-ish bridge.

The lighter moments are squandered, too. She’s instantly upstaged on “Big Fat Bass,” when Will.I.Am of the Black Eyed Peas simply chants the song’s title, his voice made to sound like a gigantic robotic bullfrog. Meantime, “How I Roll” feels like a cocaine-fueled game of patty-cake, with Spears speed-cooing some of her lewdest lyrics in a forgettable singsongy monotone.

From start to finish, every moment on “Femme Fatale” is designed for the dance floor, scrubbed clean of soppy ballads and mid-tempo treacle. That focus is welcome, but we still need a protagonist to reside at the center of the party. And in an era where Lady Gaga is pushing pop music into more imaginative turf, Spears’s hyper-sexualized girl-next-door-all-grown-up shtick feels dated, irrelevant and dull.

So as the world moves on, why not cut your losses and make the stragglers start coming to you? Viva Las Vegas.

Recommended track:

“Till the World Ends”