Historically, non-surgical treatment of achilles tendon ruptures was thought to result in much higher rates of re-ruptures in comparison to surgical treatment (on average, 20 percent versus less than 5 percent). Although some older studies found low re-rupture rates for non-surgical treatment, most seemed to find significantly higher re-rupture rates.
However, since around 2008, a number of large reliable studies from various reputable centers around the world have concluded that non-surgical achilles tendon rupture repair is just as effective as surgical repair (in terms of low re-rupture rates and final leg strength), with the added bonus of no surgery related medical or cosmetic side effects.
For a list of these, see: studies and findings in support of non-surgical treatment of achilles tendon ruptures. The key factors in a successful outcome and low re-rupture potential from non-surgical treatment are functional bracing and early weight bearing and mobilization.
Virtually all of the newer studies entailed non-surgical patients following an early mobilization protocol. In the past, most doctors would choose a conservative option of putting a patient’s foot in a cast for up to two or even three months, followed by a boot for many more weeks, followed finally by regular two shoes.
The early mobilization protocol aims to get a patient into a boot after just two weeks in a cast (or right away according to some protocols), and aims to have a non-surgical patient start partial weight bearing and full weight bearing much sooner than in the past.
If you ruptured your achilles and waited for a long time before seeing a doctor, surgery is still almost always the preferred choice of treatment. The main reason for this is that the torn ends of your tendon have probably moved away further than an inch from each other. However, some doctor believe even a several inch separation between torn ends can be healed via the non-surgical route, and one of the new studies seems to support that.
Part of the reason is that it seems like in almost all cases, when an achilles tendon ruptures, there are still connecting fibers between the torn ends. i.e., a full rupture is probably almost never a 100 percent full rupture with just a gap in between and the presence of no connecting fibers. A typical full rupture is generally not a clean cut and separation, but rather, a mop/spaghetti like separation.