Medical professionals are recommending physical therapy and activity almost immediately after most surgeries now, including total joint replacements. My mom, who's had total knee and shoulder replacements surgeries, and a good friend, who's had a hip replacement, were both up and out of the hospital bed within hours after surgery, and daily afterward. The immediate goal is to minimize the risk of pneumonia. Afterward, strengthening the joint and physical recovery.

So being back on the bike in 4-6 weeks or less sounds reasonable, assuming no complications. With a safe spinner/trainer at home you might be able to work out within a week or two.

Hospitals are also discharging patients much earlier nowadays, in part to protect patients from nosocomial infections (which is a good thing), and in part due to pressure from insurance companies (not always a good thing). Be sure you have a plan for followup physical therapy. If you're a self-starter, even in pain, your recovery will probably go well. But be honest about your tolerance for pain - most folks delude themselves about how much discomfort they can tolerate and still be self-starters. None of my immediate family members who had joint replacement or extensive spinal surgeries were cooperative with physical therapy and consequently never healed properly or got much good from the surgeries. As a result I personally followed through on my mom's physical therapies following knee and shoulder replacement surgeries. She doesn't do pain, at all, and can't even tolerate sniffles from allergies without insisting on a trip to the ER. She griped constantly but got through it without complications and, unlike my grandparents, her replacement joints don't pop loose from atrophy of muscle and connective tissues.

Two older friends who had hip replacement surgeries experienced the two possible extremes as a result of their attitudes toward recovery. One friend cooperated with the physical therapy and resumed playing tennis as soon as possible. She's slowed a bit at age 70, but is still remarkably active. Another friend wouldn't cooperate with physical therapy, developed pneumonia and died soon after.

Also, if you haven't had the full knockout regimen for surgery and the immediate followup treatment for pain before - anesthesia and morphine - do be aware that some folks have lingering aftereffects that can last weeks or months. Be sure to give permission to a family member or close friend who knows you very well, good and bad temperaments, who can advise medical personnel if it appears you're not acting like your usual self, and to take decisions on your behalf in case of emergency: hallucinations, cognitive difficulties lasting more than a day or two after surgery, mood swings, any unusual physical or mental disorientation.

I live in an apartment complex that caters specifically to folks over age 55 and many with disabilities. Many times over the years I've seen neighbors who were discharged too early and were still disoriented and either fell at home or wandered around lost in the building or around the neighborhood. So be sure you have someone available to check on you daily for the first week after surgery, both in the hospital and at home.

Regarding the surgery itself, I can't offer any suggestions. My observations of several folks who've had spinal surgeries only indicate there are too many complexities and individual differences to generalize. My grandparents both had spinal fusions in the 1970s and it didn't help much. Both suffered from chronic pain and limited mobility for their remaining 20-30 years. My mom had two kyphoplasties which did seem to help, but due to her very poor balance and gait she continued to experience falls and is now too old to be a candidate for surgery, so the only alternatives are local anti-inflammatories and pain meds. My dad got some relief from the anti-inflammatory injections in his 70s and was able to get back out of the wheelchair for his final couple of years of life.

I'm sure there are success stories with back surgery for folks aged 50 or older, but I would decline surgery for my back and neck injuries until I've exhausted every other possibility. I'll stick with anti-inflammatories and occasional pain meds. I've made some concessions to age and chronic neck/back pain by getting a bike with a heavily padded springy saddle, suspension fork, upright bars, and fatter tires than I used to ride.