Some view the prosthetic and orthotic worlds and two separate entities, two worlds that even require two distinct practitioner certifications. In some clinical cases, however, orthotics and prosthetics are combined in innovative ways to address unique patient needs. Partial foot amputation can occur at various levels, beginning at toe amputation, all the way to Symes. Each level requires individual treatment plans.
The lowest level of partial foot amputation is where a toe is amputated. Amputation of the toes can be performed with minimal to moderate loss of foot function. The great toe plays the most important role of all the toes and, when amputated, the amputee can experience difficulty in several phases of amputation. Essentially, the absence of the fifth toe can cause difficulty in ‘toe-off’ or ‘push-off’.
The most common treatment for this type of amputation is an orthotic toe-filler, which fits into the amputee’s shoe.
Boarder Ray Amputation
Boarder ray amputation involves the removal of the outer metatarsals. Amputees who experience amputation of the outer rays can still have a functional weight bearing foot, although stability may be an issue.
If the amputee is experiencing instability due to the narrow width of the foot, a custom orthotic shoe insert/toe-filler may also be indicated.
‘Transmet’ Transmetatarsal Amputation
With removal of the metatarsals, more function of the foot is lost and ‘toe-off’ can become more of a problem. The amputee is now essentially missing almost half of the length of the foot.
If the transmetatarsal amputation leaves a significant amount of the metatarsals present, the amputee may only require a toe-filler shoe insert. However, if the length of the foot is extremely short, the amputee may require an ankle foot orthosis (AFO) combined with a toe-filler. This device would improve stability and provide enough energy return to perform ‘toe-off’ successfully.
In the Lisfranc amputation, the entire metatarsal section of the foot is removed. This makes proper ‘toe-off’ impossible and ambulation is severely impaired.
The severity of this level of amputation requires a higher level of prosthetic and orthotic treatment. At this level, the amputee would require significant assistance in toe-off and the prosthetic / orthotic device will involve more of the residual limb. If sufficient support is not provided, further deformity could result and a higher level of amputation may be required in the future. Carbon fiber foot plates and suspension at the knee may be indicated.
The Chopart amputation is a forefoot level amputation that results in extreme ambulation difficulty. The amputee has lost all ability to perform ‘toe-off’ or ‘roll-over’ and a high-level prosthetic / orthotic hybrid is required.
In order to provide adequate support, the prosthetic socket should extend to the knee. A carbon foot plate can be added to allow for proper foot ‘roll-over’ and increased energy return.
This level of amputation involves the removal of the foot at the distal tibia and fibula, through the bone of the central portion of the ankle. The remaining thick heel pad provides the amputee with an excellent end-bearing residual limb.
The prosthesis required for this high level of partial foot amputation is more prosthetic than orthotic and can yield highly functional results. The prosthesis usually requires windows, or doors, to accommodate the bulbous end of the residual limb and amputees are limited as to which prosthetic feet can accommodate this prosthetic design.
In addition to the use of custom shoe inserts, toe-fillers, and prosthetic sockets, many partial foot amputees desire cosmetic restoration. Cosmetic restoration can include a custom silicone covering that can be incorporated over the devices described. For amputees missing portion of a single of multiple toes, a suction retained silicone toe prosthesis is recommended.