Lecture 31 parekh amputations

Amputations of the Foot & Ankle

Selene G. Parekh, MD, MBAAssociate Professor of Surgery

Partner, North Carolina Orthopaedic ClinicDepartment of Orthopaedic Surgery

Adjunct Faculty Fuqua Business SchoolDuke University

Durham, NC919.471.9622

http://seleneparekhmd.comTwitter: @seleneparekhmd

http://footdronline.com/

Overview

• Introduction/General considerations• Distal Syme’s amputation• Great toe amputation• Lesser toe amputation• Ray resection/partial foot amputation• Transmetatarsal amputation• Chopart’s amputation• Syme’s amputation• Below knee amputation

Amputation

• Admission of failure• Surgical defeat

Amputation

• Positive procedure• First step on road to rehabilitation

Amputation

• Save a marginally viable foot• “Win the battle. Lose the war”

Amputation

• Challenges• Selection of proper level• Maximize function• Surgical technique• Post-operative management• Footwear modifications & prostheses

Causes

1. Diabetes

2. PVD

3. Trauma

4. Chronic infection

5. Tumors

6. Congenital abnormalities

Limb Salvage

• Change in paradigm• Complete amputation• Partial amputation

General Considerations

• Plantigrade painless foot w/ stable healing wounds

General Considerations

• Preservation of greater portion of limb • Must be able to heal w/ stable soft tissue envelope

• More proximal amputation better if it yields more functional result

Wound Closure

• Balance between length of preserved bone & available soft tissue

• Immediate or delayed primary closure• Minimize trauma to wound edges• Palpate stump through flap (no rough edges)• Leave sutures in longer• Drain

Vascular Reconstruction

• Consultation• Bypass• Angioplasty

Determination of Level

• Arterial doppler ultrasound• Best initial screen• Toe pressures

• Most reliable for predicting healing• Normal >40 mmHg

• Transcutaneous oxygen measurements• Cumbersome, time consuming

Nutritional Status

• Predictive of wound healing• Total lymphocyte count > 1500/ul• Serum albumin > 3.5 g/dl• Total protein > 6.2 g/dl• Hgb > 11 g/dl

Specific Amputation Levels

Terminal Syme Amputation

• Terminal amputation of toe & nail

• Indications• Nail deformity• Infection

• Remove enough bone to close s/ tension (1/3-1/2 distal phalanx)

• Remove nail plate

• Include all proximal eponychial fold

Great Toe Amputation

• Save base of proximal phalanx (1cm)• Preserve PF & FHB• Preserve WB function of 1st ray• Minimize transfer lesion

• Avoid sesamoid resection, if possible• Complications

• Dehiscence• Varus/claw deformity 2nd toe



• Custom molded filler in shoe• Prevents sliding of

foot inside shoe

• MTP disarticulation• Partial amputation

• Residual partial toe maintains space• Blocks migration of adjacent toes

Lesser Toe Amputation

• Do not leave 1 or 2 remaining toes• Develop ulceration• Transmetatarsal amputation



• Toe separators to avoid drift• Complications

• Dehiscence• Toe drift• DF of the stump

Ray & Partial Foot Amputations

• More common• Durable • Easy to fit in shoes w/ minor modifications• Narrowing of foot

• Increased forefoot pressure• Treat w/ molded insole

• Preservation of foot length

Border Ray Resection

• 1st & 5th easiest

• Straight incisions• Loop around digit

• Longer plantar flap

Border Ray Resection

• 1st ray resection• Controversial

• Transmet???

Central Ray Resection

• Flaps not as mobile; gap may not close• Preserve soft tissue• Avoid disarticulation @ base of MT

• Midfoot instability• Further breakdown

Partial Forefoot Amputation

• 2 (or 3) medial or lateral ray resection

• ≥3 rays transmet• Lateral ray resection

tolerated better• Creative flaps often

necessary


• Aftercare• Extra depth shoes

• Accommodates remaining posture & deformities• E.g. claw toes

• Accommodates molded insoles• Shoe filler

• Prevents windshield wiper motion• Rocker-bottom sole


• Complications• Delayed/poor wound healing• Unstable foot

• Charcot• Ulceration

Transmetatarsal Amputation

• Technically easy• Tibialis anterior preserved

• Active DF• Counteracts equinus contracture

• Rule out equinus deformity• TAL may be necessary


• Incision based on viable margins• Full thickness flap dorsally• Long plantar flap• Tendons cut under tension• Cascade metatarsals

• Each successive MT ≥2mm shorter


• Bevel metatarsals• 15-20° dorsal distal to plantar proximal• 5th beveled in 2 planes (plantar & lateral)• Prevents sharp plantar edge & ulceration


• Preserve length, if possible• Shorter healed stump better than longer,

incompletely healed• Preserve MT bases


• Toe-filler, lace-up shoe• Rigid & rocker-bottom sole• +/- MAFO


• Complications• Recurrent/recalcitrant ulceration

• Most often equinus contracture• TAL

• Prominent bone• Resect

Chopart’s Amputation

• Through transverse tarsal (TN & CC) joint or “Chopart’s joint”


• Advantages• Easier than Syme’s• Allows use of a shoe w/ AFO rather than prosthesis• Less limb shortening• Preserves tough weight bearing skin of heel

• Poor choice for an active person


• Dorsal and plantar flaps

• Leave sufficient soft tissue to accommodate for width of foot

• Extensor tendons resected

• Tibialis anterior & peroneal brevis tendons preserved


• TT joint released• Achilles tenectomy

• Simple TAL leads to recurrent equinus

• TA transferred to neck of talus• PB transferred to anterior process

of calcaneus

Prosthetic Considerations

• Since minimal distance from floor, leaves little/no room for prosthesis• Poor amputation level for active patients


• AFO w/ built-in molded insole• Plastizote lining to protect & cushion the limb

• Rigid prosthesis extending to tibial tubercle • Carbon fiber plate• Posterior opening door

James Syme, 1799-1870

• Clinical professor @ U. of Edinburgh• Never earned MD• Joseph Lister

• Son-in-law• Invented modern raincoat• 1843

• Ankle disarticulation in 16 yo boy w/ TB talus & calcaneus

Syme’s Amputation

• Ankle disarticulation• Advantages

• Longer limb • Specialized skin & pad of heel• Room available for self-

suspending prosthesis w/ artificial foot

Syme’s Amputation

• Contraindicated if patient lacks viable heel pad

Syme’s Amputation

• Incisions connect points 1.5cm anterior/inferior to malleoli• Plantar incision down to calcaneus• Dorsal incision to dome of talus

• Anterior tendons resected• Anterior tibial artery ligated

Syme’s Amputation

• Release ligamentous attachments to talus• Preserve medial neurovascular bundle

• Common cause for wound breakdown

Syme’s Amputation

• Protect subcutaneous attachment of Achilles• Subperiosteal dissection calcaneus

• Technically difficult• Avoid penetrating skin @ this level

Syme’s Amputation

• Cut malleoli flush w/ plafond• Preserve medial & lateral aspects

• Important to aid in prosthesis suspension• Heel pad sutured to bone

• Otherwise becomes hypermobile & problematic

Syme’s Amputation

• Plantar fascia sutured to deep fascia on anterior aspect of leg• Do not resect dog ears (can lead to failure)• Can be done in 2 stages for infection

Syme’s Amputation

• Advantages over BKA• Full lower leg segment allows for greater quad

leverage• Minimal prosthetic training• Lower energy cost • Higher velocity• Greater stride length

Syme’s Amputation

• Success rate 50-90%• Early failure

• Dysvascular heel pad most common• Late failure

• Progressive PVD • Distal bony prominences

• Hypermobility of stump• Neuroma formation• Heel pain


• Door or window allows donning & doffing prosthesis in presence of bulbous distal stump

Pirogoff’s Amputation

• Variation of Syme’s • Portion of calcaneus preserved &

internally fixed• Advantages

• Longer soft tissue flaps • Less shortening

• Disadvantages• Symptomatic non-union

Boyd’s Amputation

• Neither Pirogoff’s nor Boyd’s amputations performed very often• Increased surgical time• Few advantages• Should only be performed if patient is

low demand & will not use prosthesis

BKA

• Necessary when foot salvage fails• Tibial resection 9-12cm below joint line• Fibular resection 1cm proximal to tibia• Long posterior flap

• 12-15cm

Energy ExpenditureAmputation

LevelEnergy, Above

Baseline (%)

Speed (m/min) Oxygen Cost (mL/kg/m)

Long BKA 10 70 0.17

BKA 25 60 0.20

Bilat BKA 40 50 0.20

AKA 65 40 0.20

Wheelchair 0-8 70 0.16

RE ECT

the ankle

the foot

Lecture 31 parekh amputations

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