It’s Fast to Relast
September 2012 Issue
It is safe to say that most patients do not readily embrace the thought of having to wear custom-molded shoes. Their list of complaints is lengthy and familiar to the pedorthist and orthotist alike:
- "Those are the ugliest shoes I've ever seen."
- "I can't afford to pay $600 for one pair of custom shoes."
- "Why do they take so long to make?"
- "You mean I'll only have one pair of shoes that I will have to wear every day?"
A pair of shoes that sits in a patient's closet and is never worn is a terrible waste of money and time. One solution to this age-old problem is a shoe modification known as relasting. Relasting involves taking a stock shoe and reshaping it to fit and accommodate a severe deformity.
Relasting can be used to help fit a shoe around midfoot and hindfoot deformities such as a Charcot foot, or a rigid severe planus foot such as one with stage IV posterior tibial tendon dysfunction. Of course, relasting can be used to accommodate any number of other midfoot issues: a prominent base of a fifth metatarsal, clubfoot deformity, malunion or malalignment of a Lisfranc injury, rheumatoid arthritis, and countless others.
By using commercially available shoes, you automatically remove the stigma attached to wearing ugly custom shoes. By all outward appearances, no one but the patient can tell that he or she is wearing a special shoe, so patient acceptance and compliance automatically increase. As any experienced practitioner knows, the two-headed beast of cosmesis and social acceptance plays a significant role in whether an orthotic, prosthetic, or pedorthic device actually gets used.
Relasting addresses another common custom shoe-related complaint-turnaround time. This modification can be performed in-house and turned around in a day or two as opposed to the several weeks or even months it takes to build a pair of custom-molded shoes. The cost is appreciably less, as well. Many facilities that modify shoes in this way are able to do it comfortably for much less than the cost of custom-made footwear. Some insurance companies reimburse for relasting when it is billed as the Healthcare Common Procedure Coding System code L-3254 (non-standard size or width).
The modification itself is not difficult to do, but it requires some specialized skills and a little time.
The first step is critical: proper shoe selection. Fit is important because the less the shoe needs to be widened, the better the fit, function, and appearance will be. If the deformity is unilateral, the contralateral shoe needs to fit the unaffected foot appropriately. When fitting the shoes, it is important to keep in mind approximately how much the shoe will need to be widened, as there is a finite amount of volume in any given shoe. In other words, if you widen the shoe, you will necessarily shorten it from heel to toe. If the shoe is fit with the normal 3/8 inch of additional space beyond the longest toe before relasting, the shoe could end up too short, touching or even crowding the toes.
The original construction of the shoe should also be considered. While there are many styles and types of shoes that can be relasted, there are some that work better than others. For the modification to work best, the shoe should have good structural integrity. Shoes with solid, thick wedge outsoles work very well. Dress shoes with leather outsoles cannot be relasted. Molded, unit bottom shoes are fairly easy to work with as long as they are solid, but soles with internal baffles to lighten their weight can be tricky to relast because the structure is compromised when the walls of the baffles are cut. Other outsole features to avoid are internal, shock-absorbing "gimmicks" such as air bladders, gel packets, and springs. It's not that these types of shoes can't be relasted, but the special features (such as air bladders) would most likely have to be removed or rendered inoperable. So while the relasted shoe looks good cosmetically, if the patient purchased the shoes specifically for the special shock-absorbing components, he or she may be upset to learn that those components were removed or disabled.
Once the shoe has been selected, the next step is to make a pattern for the relast. The pattern can be made by tracing the patient's foot while he or she is fully weight bearing or tracing a plaster cast derived from a foam impression of the patient's foot. Tracing the plaster model may be more accurate since this process eliminates the variability that might result from the practitioner changing the pencil angle as he or she works around the patient's foot and maneuvers around the leg. To obtain the forefoot shape, overlay the insole of the shoe onto the tracing.
The first step in actually modifying the shoe is to remove the outermost layer of the outsole. With many athletic shoes, this is a rubber outsole that can be easily removed by heating it with a heat gun and peeling it off. If it is a unit bottom or full crepe sole, either grind the tread off with a sander or cut it off using a knife or band saw. Since the shoe will require a new outsole to fit the new shape of the shoe, don't worry about preserving the outsole to reapply as you would when adding a lift or rocker sole to a shoe.
Once you have removed the outermost layer, draw a line where the cut will be made to eventually widen the shoe. Following this line, cut the remaining outsole and midsole lengthwise in the area of the shoe that is going to be widened. This can be accomplished by drilling a hole using a 3/8-inch bit at each end of the line and connecting the holes with a power jigsaw or a handheld reciprocating saw while the shoe is clamped securely in a benchtop vise. The depth of the cut should go all the way through the outsole, midsole, and sockliner inside the shoe. Once the cut has been made, use the cast spreader to pry open the cut.
With the cast spreader propping the gap open, wedge a small block of rigid neoprene or similar material in its place to hold the gap open.
The next step is the most important and potentially tedious. Strategically shape and insert a few small wedges of firm 1/4-inch material into the cut so that the shoe will accurately accommodate the pattern inside the shoe. Lengthen, shorten, and move the wedges around until the shape fits the pattern.
Once the shape has been attained, glue a dam of thin cardboard inside the shoe over the gap. Then turn the shoe over so the bottom of the shoe is facing up. Level it and fill the entire gap with a stiff, space-filling material. Variable durometer viscoelastic polymers (mixed as firm as possible) or expandable urethane foam work well.
Once it has hardened, grind off the excess, and add a new outsole to finish the relast.
You now have a cost-effective "custom" shoe that looks just like its unmodified mate from the top and sides. You also have a satisfied and very grateful patient.
Dennis Janisse, CPed, is president and CEO of National Pedorthic Services, headquartered in Milwaukee, Wisconsin. He also is a clinical assistant professor in the Department of Physical Medicine and Rehabilitation at the Medical College of Wisconsin, Milwaukee; adjunct professor at University of Pittsburgh, Pennsylvania; and director of scientific affairs for Orthofeet, Northvale, New Jersey.