Park et al 2013 completed a review of 17 trials involving acupuncture and ankle sprains. Of those, only 3 met inclusion criteria. These studies used randomization and sham treatment.
Acupuncture was added on to traditional physiotherapy and exercise rehabilitation. The 3 studies indicated that acupuncture relieved pain better than therapy alone (rr = 0.61) and facilitated return to function 3-4 days faster than without it.
Given how few proper studies were done properly, no conclusions can yet be drawn and more research is required.