LOWER LIMB LEVEL AMPUTATION 1) PARTIAL FOOT AMPUTATION 2) TRANS TIBIAL AMPUTATION 3) THROUGH KNEE AMPUTATION 4) TRANS FEMORAL AMPUTATION 5) HIP DISARTICULATION
Introduction • Indication for leg amputation have undergone a big change during • the last 100 years: • Before it was a life-saving surgical intervention with a high mortality rate in the 19th century • Today, plastic surgery and microsurgery are employed to obtain • a “functional residual limb with weight-bearing ability at its distal end." • Anatomical configuration does largely predetermine the required • weight-bearing ability at the distal end of the residual limb and • reveals the benefits of knee disarticulation. • - Whenever possible "peripheral amputations” should be carried out, • especially in cases of foot level indications. They offer the best • preconditions for the fitting, including good weight bearing ability, • and also recommend a “residual limb according to patient requirements."
1) PARTIAL FOOT AMPUTATION • Foot amputation levels range from: • Removal of individual distal toe segments • Disarticulations in the basal toe joint • Removals in the mid-foot area such as metatarsal amputations • Disarticulation in Lisfranc joint , Chopart joint • Amputations of the calcaneal part of the foot. • The trans-malleolar amputation according to Syme is a transition • amputation from foot level to lower limb level amputation. • -The basic principle is to always conserve as much of the limb as possible, • because with increasing amputation level the standing surface • becomes smaller. • Amputation technologies are aimed at the conservation of the foot sole • in order to make use of both its load bearing capability and its proprioception. • -This way a patient with calcaneal stump will be able to walk a short distance • even when not wearing the prosthesis.
1 2 8 1) Distal Phalanx 3 2) Disarticulation proximal Inter Phalangeal joint 4 3) Disarticulation of toes 4) Distal Metatarsal 6 6) Lisfranc – Tarso Metatarsal disarticulation 7 7) Chopart – Talonavicular + Calcaneo Cuboid disarticulation 8) Metarsal /phalangeal Ray Foot amputations levels 5 5) Proximal Metatarsal
Lisfranc a) Lisfranc Amputation • Advantages: • Good proprioception. • No PTB suspension / weight bearing. • - Patient can walk short distance without prosthesis. • Disadvantages: • Appearance of equino-varus deformity. • Prosthesis creates a leg length discrepancy. • Bony & sensitive stump – adaptation problems. • - Difficult to accommodate in standard shoes.
Chopart b) Chopart Amputation Avantages and Disavantages are the same as the Lisfranc amputation • Advantages: • Good proprioception. • No PTB suspension / weight bearing. • - Patient can walk short distance without prosthesis. • Disadvantages: • Appearance of equino-varus deformity. • Prosthesis creates a leg length discrepancy. • Bony & sensitive stump – adaptation problems. • - Difficult to accommodate in standard shoes.
Pirogoff c) Pirogoff Amputation • Advantages • End-bearing capabilities. • Self-suspension due to bulbuous shape. • Good proprioception. • - Long lever-arm: reduced surface pressure. • Disadvantages: • Too long to use standard foot. • No possibility to use standard prosthetic foot • and alignment system. • - Poor cosmetic.
Syme d) Syme Amputation • Advantages: • End-bearing capabilities. • Self-suspension (bulbuous end). • Long lever arm: reduced surface pressure. • Good proprioception / control. • - Possible to use standard foot & alignment system. Disadvantages: Poor healing. Poor cosmetic, bulbous contour of distal end. Movement of distal stump-pad. Difficult donning & doffing of the prosthesis.
Foot amputation : Summary a) Advantages - A full end bearing stump - A limited functionnal loss - Patient can walk for short distances without prosthesis • Proprioception : proprioceptive properties of the sole of the foot • are kept good in most cases • Balance : relatively easy for patients to keep their balance especially • on uneven ground • Phsycological aspect: The usual aspects of an amputation are • probably reduced because of the limited loss of function and appearance. • In the case of vascular operations where amputation of the other limb • can be expected at a later stage, it is an advantage to keep • as much function as possible.
b) Disavantages • Poor wound healing specially in case of poor peripheral blood supply • (eg: peripheral vascular disease ) The scar is quite often large areas of scarring - Bony overgrows may become sharp and cause problems - Adherence of the suture to the underlying bones = more sensitive to pressure or rubbing action • Destruction of the normal weight bearing structure of the foot: this will lead • to a changes of distribution forces along the sole of the foot. • Ex: in case of total or partial toes disarticulation = more metatarsal head pressure.
Muscle imbalance : • between the flexors ( tibialis anterioris) and the extensors ( triceps surae) = • the Achilles tendon is pulling the stump in equinus. • between the supinators (tibialis anterioris) and the absence of pronators ( LPL). • the stump is pulled into a inversion/supination deformity. ( Chopart Amputation) - Cosmetical problem due to the posterior migration of the calcaneus • Problems with donning and doffing with bulbous end stump: it can be solved by • making a removable panel or leaving a panel section completly open. - Reduced body balance due to a reduced area of support • Contractures : the toe stump of a partial toe amputation often develops • contractures in dorsi-flexion
2) TRANS TIBIAL AMPUTATION • Advantages: - Good prospect for prosthetic rehabilitation. - Longer stump = better control & less surface pressure. • Disadvantages: • - Socket fit must be very accurate due to bony mapping. • - No end-baring possibility – reduced proprioception. • - Very short stump = risk of stump – socket pseudarthrosis. • - Very long stump = distal stump is bony; • acute risk of abrasion / wound.
3) THROUGH KNEE AMPUTATION • Advantages: • End-bearing possibility • Long lever-arm: reduced surface pressure • + good control during gait • Self suspension • No need of ischial weight bearing • - No need of suspension belt • - For children: bone growth is conserved • - Better proprioception than in TF amputations • - No bone section – lighter surgical act.
Disadvantages: • Need to use specific knee-joint to avoid • thigh length discrepancy • - Cosmetically less attractive than TF prostheses • Bulbous-end = donning & doffing is more difficult • than in TF socket
- The knee disarticulation amputation (through-knee-amputation) is executed if it is no longer possible to maintain a short residual section of the lower leg. -Due to the anatomical prerequisites, functional and cosmetic requirements, it is more convenient to use modular componentry for better fitting. - In contrast to a trans-femoral amputation, the residual limb can be fully loaded after knee disarticulation. Because the femoral condyles transfer body weight to the prosthetic socket, no tuberosity seat is required. -The bulky shape of the condylar residual limb provides for a rotationally-stable connection to the prosthetic socket. -A soft socket of thermoplastic PE foam is anatomically shaped inside, and by compensating for the undercuts offers a conical shape outside. This makes for easy donning of the prosthesis during sitting. -The musculature of the residual limb remains balanced because the adductors have not been transected, while the long lever arm allows for good control of the prosthesis. - When compared with the qualities of a trans-femoral amputation, knee disarticulation offers advantages to both geriatric and athletic patients.
4) TRANS FEMORAL AMPUTATION • Advantages: • Healing rate is greater than for more • distal amputations. • The residual limb in many cases is easier to • fit with a socket. • - Longer stump = better control & less surface pressure. • - Few bony prominences = less problem of socket adaptation. • - Medium length stumps with good end-cushioning are ideal.
TF: Disadvantages: • - Mortality is greater for more proximal amputations. • - More surgical complications. • Cut muscle bellies retract, atrophy and • lose their function; myoplasty will prevent this problem. • Rehabilitation for prosthetic walking is less successful • than with more distal amputations • - No end-bearing possibilities as for knee disarticulation. • - Need of a suspension (suction or belt). • Mobility is reduced – increased energy is needed • during gait.
5) HIP DISARTICULATION Advantages: - None. • Disadvantages: • - Heavy prosthetic device. • Reduced mobility & Increased energy • needed during gait. • - Uncomfortable in sitting position – hip unbalance.
The various amputations in the hip area, such as the inter-trochanteric • amputation, the hip disarticulation and the hemipelvectomy • are fitted with pelvic prostheses. • In case of accidents or tumors, a more distal amputation • level is not possible, a prosthesis of this type is indicated. • As opposed to a "true disarticulation" in the hip joint area, • in this case, an amputation is performed in the upper portion of • the femur with proximal sections of the femur retained. • - If one pelvic half must be partially or completely removed, • it is called a hemi-pelvectomy. In this case the conditions • of support and encasement are especially difficult. • - By removing the ischial tuberosity the seating area is lost, • and due to the loss of the os ilium the encasement surface decreases • so that the lower thoracic area may require enclosure by the pelvic socket. • -In the case of hemi-pelvectomies, not only are the organs of motion involved, • but often artificial outlets for the bladder or intestine are required, • making orthopaedic technical fitting even more difficult.