Surpass is a good topical analgesic. Systemic NSAIDs like bute can cause ulcers when used frequently for long durations. Previcox is pretty good specifically for arthritic type pains and doesn't cause as many tummy issues as Bute. It's cheaper to buy the dog previcox than it is to buy the Equioxx, and you use about half a dog tablet in a dose- you can crush it or just put it on top of feed.
Sports Medicine boots provide good tendon support, as they have and extra strap that goes under/around the fetlock to kind of keep it from overflexing.
I've never tried them personally, but a friend of mine swears by magnetic boots for her horse's sore, overused-in-a-previous-life hocks. I was reading posts further down, and if it's a collateral ligament in the hoof itself you may want to look at the magnetic hoof/bell boots here - there's the Veredus expensive option and the Magntx version for more like $40. They can't live in those, but leave them on for 4-12 hours at a stretch for therapeutic effects.
Magic Cushion is a pine tar/analgesic packing for the foot. I use it overnight at shows when my horse is jumping a lot (and when she had some foot issues last year)- pick/brush the hoof clean, put on some gloves because it's black and sticky, pack those bad boys, and either use a diaper or a femal-pad, and duct tape that bad boy. Leave overnight. PROMISE he'll feel better- my mare went from totally sore to "paddock surfing" jumping the property fences for funsies.
As far as joint supplements, Cosequin ASU is the best one you can get in SmartPaks (if you have a barn like mine that doesn't do buckets/scoops), and Actistatin is truly my favorite, has more clinical evidence behind it, and is $150 for a 90-day supply. Link to product website