I am a physician, but not an orthopedic surgeon, and I wouldn't want to even speculate on Jones' injury without more information. Here's a nice lay overview of some common sports hip injuries:
http://www.coreperformance.com/knowledge/injury-pain/hip-injuries.html
Here's a nice powerpoint presentation discussing some of the many options to be considered in a differential diagnosis of sports hip injuries:
http://medicine.nevada.edu/Documents/unsom/statewide/echo/clinics/sports/Echo_Extra_Artic_Hip.pdf
Hip dislocations are extremely tricky, because the blood supply to the hip can be disrupted, leading to avascular necrosis (AVN) if prolonged. A disrupted blood supply causes ischemia to the hip, and if not resolved can lead to irreversible cell death and degeneration. This is what happened with Bo Jackson, who ended up needing a hip replacement. The following article has a nice lay overview, including a detailed discussion of the hip anatomy with some nice illustrations:
http://regressing.deadspin.com/could-modern-medicine-have-saved-bo-jacksons-career-1443105382
Reducing a dislocated hip generally requires general anesthesia and muscle relaxation ("paralysis"), because the surrounding muscles are so strong that it is generally not possible to get good reduction without deep anesthesia and relaxation. I've seen lots of times that 4 hulking orthopedic surgeons have struggled to reduce the hip of an emaciated little old lady who fell, without success, until proper conditions have been obtained. The Pats obviously don't release medical details, but we don't know of anything that suggests that Jones was hospitalized for this. A hip dislocation which cannot be reduced required urgent surgery to avoid the risk of AVN.
Bryan Kelly and colleagues at the Hospital for Special Surgery in New York (perhaps the pre-eminent orthopedic specialty hospital in the U.S.) surveyed the NFL Injury Surveillance System database for injuries between 1997 and 2006, and found a 3.1% incidence of hip injuries, with an average of 12.3 days lost per injury. Most injuries were minor contusions or muscle strains. Intra-articular injuries (those in the hip joint itself) were more severe, and resulted in a greater loss of playing time. The authors characterized a "sports hip triad" pattern common in the elite athlete involving labral tear, adductor strain, and rectus strain). Labral tears generally are treated with arthroscopic surgery followed by rest. We have yet to hear of Jones requiring surgery.
There are way too many possibilities to speculate what Jones' injury might be, but the hip joint is extremely complex and not to be trifled with. The last thing I would want would be to underestimate these kind of injuries and try and rush a player back. Nerve impingement, avascular necrosis, and chronic osteoarthirisis are all potential issues which could cause long term problems.
