PARTIAL FOOT PARTIAL FOOT AMPUTATION AND AMPUTATION AND PROSTHETICS PROSTHETICS MANAGEMENT MANAGEMENT

SUBMITTED BY

VANDANAINTERN (IPH)

BASIC ANATOMY OF FOOTBASIC ANATOMY OF FOOTThe foot is composed of 26 skeletal bones

held together by muscles, ligaments and tendons.

These 26 bones are divided into three groups:

Phalanges: consists of fourteen bones in the toes Metatarsus: consists of five slender bones located in the front of the instep Tarsus: consists of seven bones that form the back of the foot 

FOOT AMPUTATION FOOT AMPUTATION LEVELS:-LEVELS:-1. Transphalangeal amputation

(toe disarticulation).2. Transmetatarsal amputation

(TMA).3. Lisfranc amputation.4. Chopart amputation.

CAUSES OF AMPUTATION:-CAUSES OF AMPUTATION:-1. INFECTION The most common cause of partial

foot ablations today is infection with necrosis in diabetic patients.

A normal bony prominence, combined with sensory neuropathy and inappropriate shoe wear, often produces infection.

2. ISCHEMIA Ischemia of the foot may result from a

variety of conditions,including peripheral vascular disease with or without diabetes mellitus,vasoconstriction following treatment of hypotension,and frostbite

Smoking can be an aggravating factor in all these conditions.

3.TRAUMAThe most common traumas leading to partial

foot ablations are those resulting from:- accidents with moving machinery, such as

lawnmowers or motor vehiclesCrush injuriesDegloving injuries that expose a significant

portion of the skeletal structure Thermal injuries which include frostbite and

burns.

Healed motor vehicles amputation of the 1st,2nd nd 3rd toes. The 4th nd 5th toes are sensate .

Toe disarticulationsToe disarticulations

Toe disarticulation is done at the metatarsophalangeal joint.

Even when osteomyelitis is present in the distal phalanx of the great toe, sufficient skin can often be salvaged to permit an interphalangeal disarticulation.

The remaining proximal phalanx will aid with balance and result in a much better gait than results after disarticulation at the MTP joint.

Disarticulation of the second toe at the MTP joint, by removing lateral support from the great toe, may result in a hallux valgus (bunion) deformity.

If the other toes like 2nd,3rd,4th and 5th alone is disarticulated, the adjacent toes will tend to close the gap and restore a good contour to the distal forefoot.

Ray AmputationsRay AmputationsIn ray amputation, a toe and part or all

of the metatarsal are removed.With the first or medial ray, as much

metatarsal shaft length should be left as possible to allow for effective elevation of the medial arch with custom molded insert.

A single amputation of ray 2,3 or 4 affects only the width of the forefoot.

A radiograph of first ray amputation and the foot.

4th ray amputation

Transmetatarsal Transmetatarsal AmputationAmputation

Transmetatarsal amputation should be considered when two or more medial rays or more than one central ray must be amputated.

For maximum function, it

is important to save as much metatarsal shaft length as can be covered with good planter skin distally.

Tarsometatarsal (Lisfranc) Tarsometatarsal (Lisfranc) DisarticulationDisarticulation

Disarticulation at the tarsometatarsal joints.

Its mostly seen in case of trauma, sometime in foot tumour and can also be in case of infection

Midtarsal (Chopart) Midtarsal (Chopart) Disarticulation Disarticulation

The chopart disarticulation is through the talonavicular and calcaneocuboid joints.

BiomechanicsBiomechanicsNormal foot functionNormal foot function The normal foot is an extremely complex structure. Load-Bearing Structure The foot is the means whereby the ground reaction

forces generated during physical activities are transmitted to the body structure. During normal level walking these loads are directed initially onto the heel.

Once the foot is flat and until the heel leaves the ground as push-off is initiated, the supporting forces are shared between the heel and the ball of the foot, with only a small contribution from the lateral aspect of the midfoot.

Load transmission is commonly attributed to the arch structure of the foot.

Functional loss after Functional loss after amputation amputation The loss of normal foot function after

amputation is progressively more severe the more proximal the site of amputation.

The primary aspects of the loss of foot functions are: load-bearing capacity, stability and dynamic function.

Prosthetics Prosthetics management of management of partial foot partial foot amputationamputation

Amputation of the toesAmputation of the toesThe functional loss associated with the

amputation of one or more toes is primarily a reduction in the forefoot load-bearing area, resulting in increased pressure on the metatarsal heads, which are also more exposed by the removal of the toes.

If the hallux is remove, when foot function is also be compromised by the loss of active flexion of the 1st metatarsophalangeal joint.

For normal walking, the loss of the toes is not a major functional problem, but loss of big toe makes running and participation in competitive sports more difficult because of the loss of active push-off.

Prosthetsis for toe amputation are:

Toe filler to reinstate normal foot shape and prevent deformation of the shoe.

Provision of a toe spacer may be beneficial in patients where one of the central toes has been removed.

Silicone replacement of the toes offers optimum cosmesis.

Amputation of the second through fifth toes.

When further pressure reduction is required at the amputation site, a rocker sole with its apex behind the metatarsal heads may be added to the shoe.

Ray AmputationsRay AmputationsThe functional consequences of

amputation of one or more rays of the foot depend on the position and extent of the tissues removed. There will be a reduction in the forefoot load-bearing area.

Stability of the prosthesis on the residual foot requires intimacy of fit.

Silicone prostheses for excellent cosmetic restoration.

Transmetatarsal Transmetatarsal AmputationAmputationThe functional loss that occurs when the

amputation procedure involves the removal of the metatarsal heads.

In these amputation, the entire normal forefoot load- bearing capacity is eliminated.

The removal of the metatarsal heads means that no longer transfer the forefoot ground reaction force directly onto the planter surface of the residual foot, therefore, the rotational stability of the prosthesis interface will require special attention.

A prosthesis with a molded or laminated socket, built up to replace the lost forefoot, including a soft liner or anterior pad.

UCBL foot orthosis, covering the dorsum of the foot

Tarsometatarsal and Tarsometatarsal and transtarsal amputationstranstarsal amputationsThe designs of prostheses that have

been produced for these amputation levels are categorized as perimalleolar designs and high-profile designs.

Perimalleolar designs include inframalleolar designs, where the proximal trimline is below the malleoli

Supramalleolar designs, where the proximal trimline encloses the malleoli.

In these designs, the forefoot dorsiflexion moment is resisted by a force couple created by socket interface forces located anteriorly at the socket brim and posteriorly at heel level.

Forces required to resist the dorsiflexion moment

Different types of Different types of prosthesis designs:-prosthesis designs:-

Collins partial foot prosthesis.

High-profile designs

Slipper type elastomer prosthesis (STEP).

Imler prosthesis

Lange silicone prosthesis

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