Toe Amputation 

Updated: May 28, 2020
Author: Adam Frankel, MBBS, PhD; Chief Editor: Erik D Schraga, MD 

Overview

Background

Toe amputation is a common procedure performed by a wide variety of healthcare providers. The vast majority of toe amputations are performed on patients with a diabetic foot.[1] Although regional variation is noted, most of these procedures are done by general, vascular, and orthopedic surgeons (particularly those subspecializing in foot and ankle surgery); in some countries, podiatrists are involved.

There are three broad indications for amputation of any body part, as follows (see Indications)[2] :

  • Dead
  • Deadly
  • Dead loss

Before any amputation, the clinician should ensure that the patient’s medical circumstances have been optimized (ie, should "reverse the reversible"). With impending toe amputation, this step encompasses such measures as glycemic control and consideration of revascularization when severe macrovascular disease is contributing to ischemia.

The method of toe amputation (disarticulation vs osteotomy) and the level of amputation (partial or whole phalanx vs whole digit vs ray) depend on numerous circumstances but are mainly determined by the extent of disease and the anatomy. With any amputation, the degree of postoperative functional loss is generally proportional to the amount of tissue taken. The great toe is considered the most important of the toes in functional terms. Nevertheless, great-toe amputation can be performed with little resulting functional deficit.[3, 4]

Indications

A “dead” toe is one in which the blood supply is so completely impeded that infarction and necrosis develop (see the images below). Infarction results in dry gangrene, with nonviable tissue becoming dry and black in color (because of the presence of iron sulfide, a product of the hemoglobin released by lysed erythrocytes).

Gangrenous fifth toe. Dubious perfusion in fourth Gangrenous fifth toe. Dubious perfusion in fourth toe.
Lateral two toes for amputation (lateral view). Lateral two toes for amputation (lateral view).

In Western societies, a “dead” toe is most commonly seen as a complication of diabetes mellitus[5] and is due to a combination of macrovascular and microvascular disease. Other major risk factors for peripheral vascular disease (as for all atherosclerotic diseases) include smoking, hypertension, and hyperlipidemia. Rarely, pathologic processes confined to the microvasculature are to blame (eg, thromboangiitis obliterans [Buerger disease], vasospastic diseases, severe frostbite).

The “deadly” category generally refers to a more proximal disease processe that can result in systemic sequelae. For example, a large limb segment affected by wet gangrene (with macroscopic putrefaction and surrounding cellulitis) can be deadly if not addressed urgently. Malignancy may also necessitate amputation, though infrequently.

A toe is a “dead loss” when it is diseased to the point where it is irreparable (as with chronic osteomyelitis), it ceases to be functional (as with significant trauma), or it is impeding function (as with neuropathic pain).

Cases in which ray amputation has been performed to treat foot macrodactyly in children have also been described.[6]

Contraindications

The main contraindication for toe amputation is poor demarcation of infarcted tissue (patchy gangrene). If the borders of the infarcted area are unclear, the surgeon cannot know the true extent of the disease and hence cannot be certain of amputating to a region of adequate blood supply.

More broadly, amputation of any body part is contraindicated when it will result in a reduced quality of life in the setting of a limited life expectancy. However, this contraindication is not usually relevant to toe amputation.

Technical Considerations

Anatomy

The phalanges of the foot correspond, in number and general arrangement, with those of the hand; two are found in the great toe, and three are found in each of the other toes. However, the phalanges of the foot differ from the phalanges of the hand in terms of size, with the bodies of the phalanges of the foot being much reduced in length and, especially in the first row, laterally compressed.

The body of each proximal phalanx is similar to the metatarsals in being convex above and concave below. The base is concave for articulation with the respective metatarsal, and the head presents a trochlear surface for articulation with the second phalanx.

For more information about the relevant anatomy, see Foot Bone Anatomy.

Outcomes

Vassallo et al performed a single-center study aimed at determining healing, reulceration, reamputation, and mortality rates at 1 year after toe amputations in 81 patients with type 2 diabetes mellitus.[7] In 12.4% of participants, the amputation site remained incompletely healed; 80.2% of the study cohort had a completely healed amputation site at 12 months. Only 20.9% had no complications in 12 months. Over the study period, 45.7% of subjects had had a new ulcer at a different site. Forty-eight participants (59.3%) underwent further surgery, either to revise the original amputation site (n = 31) or to amputate at a new site (n = 17). Mortality was 7.4%. 

 

Periprocedural Care

Patient Education and Consent

Prevention and early detection of future disease should be discussed with the patient. Education on pressure-area pathogenesis is important as part of a strategy to encourage the patient to prevent further problems. Daily self-inspection aids in early detection of recurrent episodes. Regular visits with a podiatrist should be encouraged to ensure that shoes are well fitted. Thick cotton socks help to prevent pressure areas, and enclosed shoes act as a barrier to the entry of foreign bodies. Informed content must be obtained.

Preprocedural Planning

Antibiotics should be considered in accordance with the individual patient’s circumstances and local guidelines. Australian recommendations for perioperative antibiotics include the following options:

  • Cefazolin 1 g intravenously (IV) at induction or
  • Benzylpenicillin 1.2 g IV at induction followed by 1.2 g every 6 hours for 24 hours or
  • Metronidazole 500 mg IV at induction followed by 500 mg every 12 hours for 24 hours

There has been some debate regarding the appropriate duration of antibiotic therapy for diabetic foot infections after surgical amputations. In an analysis that included toe amputations (n = 155), as well as midfoot (n = 280) and hindfoot amputations (n = 47), Rossel et al found no benefit in continuing postoperative antibiotic administration after routine amputation for diabetic foot infection and suggested that in the absence of residual infection, antibiotics should be discontinued.[8]

Deep vein thrombosis prophylaxis should also be considered, in accordance with both patient factors and local guidelines.

Equipment

The materials required for toe amputation include the following:

  • Indelible pen
  • Povidone-iodine, chlorhexidine, or a similar surgical disinfectant
  • Scalpel with No. 15 blade
  • Toothed forceps
  • Skin hooks/rakes
  • Bone cutter
  • Bone nibbler
  • Curette
  • Diathermy
  • Dressings (including gauze soaked with povidone-iodine)

Additional equipment may be needed, depending on the exact method used, but such equipment usually is readily found on a general surgical tray.

Patient Preparation

Anesthesia

Many options are available for anesthesia. However, the usual patient has significant medical comorbidities, and these should be considered carefully in the context of anesthesia.

Because of the high prevalence of diabetes mellitus in patients undergoing toe amputation, anesthesia requirements may actually be minimal as a result of peripheral neuropathy. Local anesthesia alone is often satisfactory, either in the form of a ring block or a regional (usually ankle) block. Spinal or epidural anesthesia can also be used, though the use of antiplatelet or anticoagulant medications in this population is frequent. General anesthesia may also be feasible.

Positioning

Toe amputation is best performed with the patient in the supine position.

Monitoring & Follow-up

Adequate postoperative analgesia must be ensured, though the requirement is often minimal as a result of peripheral neuropathy.

The minimal pain usually experienced postoperatively often allows early mobilization. Some authors caution against mobilization if cellulitis is present.[2]  As the patient begins to mobilize, both feet should be observed (particularly in the diabetic patient) for the development of new pressure areas. Such pressure areas may develop as a result of alteration of the remaining ipsilateral foot architecture (depending on the type of amputation performed) or subtle changes in gait that affect the contralateral foot.

Dressings should be inspected regularly and changed as required.

 

Technique

Approach Considerations

In any toe amputation, thorough assessment of the neurovascular status of both limbs is essential. In Australia, this includes a preoperative assessment with duplex ultrasonography (US), even in a patient with all pulses intact. Consultation with a vascular surgeon may be worthwhile.

A retrospective study by Stone et al that reviewed 333 toe and foot amputations with the aim of determining clinical factors associated with postamputation wound healing found that toe pressures were superior to duplex US parameters for predicting healing in this setting.[9] Preamputation toe pressures of 47 mm Hg and above were associated with wound healing, and no other noninvasive vascular studies predicted healing in the presence of confounding factors. The authors suggested that toe pressures should be routinely obtained before toe amputation.

The amputation should be performed at a level that makes anatomic sense, provides appropriate treatment for the patient’s circumstances, and minimizes the risk that further intervention will be required in the future. In all cases, the specimen should be sent for pathologic examination.

Amputation of Toe

After informed consent has been obtained and the patient has been adequately anesthetized, a sterile field is set up so that the surgeon has access to the entire foot on the affected side. As noted (see Periprocedural Care), antibiotic prophylaxis should be considered if the patient is not already on regular antibiotics.

Steps common to all toe amputations

Incision lines are marked on the skin as appropriate for the planned amputation (see the images below). For a partial toe amputation, a plantar-based flap is commonly used. However, several other possibilities exist (eg, dorsal flap, side-to-side flap, and fish-mouth flap). The most important principles are to ensure that the flap is viable before closure and to perform a tension-free repair. For a disarticulation or a transmetatarsal amputation, a long plantar flap is the best choice.

Markup for second-toe amputation (fish-mouth skin Markup for second-toe amputation (fish-mouth skin excision): anterior view of (dry) gangrenous toe.
Markup for second-toe amputation: posterior view. Markup for second-toe amputation: posterior view.
Adjacent toe amputations: anterior view of markup. Adjacent toe amputations: anterior view of markup.

All necrotic tissue is debrided. If infection is present, the tendon sheaths must be drained of any purulent material (which often tracks along them). Microbiology samples may be sent for culture and sensitivity testing. Neurovascular bundles are ligated or cauterized as they are dissected.

If the wound is left open, many dressing options are available. Commonly, the wound is loosely packed with gauze soaked in saline or povidone-iodine (though there is only limited evidence to support the latter). Other alternatives are available, such as calcium-alginate fiber. A nonstick dressing (eg, paraffin gauze) over the top is helpful for holding the packing in place. Generous amounts of cotton wrapping are applied (particularly over potential pressure areas), and a crepe bandage is applied to finish the dressing (see the image below).

Dressing suggestion: wound packed with calcium-alg Dressing suggestion: wound packed with calcium-alginate dressing, paraffin gauze on top (crepe bandage to finish).

Partial toe amputation with osteotomy

For amputation of one of the medial two toes, preservation of the base of the proximal phalanx is beneficial, but for different reasons in each toe. In a hallux amputation, preservation of the base of the phalanx preserves the flexor hallucis brevis (FHB) insertion, and this helps maintain stability during terminal gait phase.[10] In a second-toe amputation, the retained segment helps maintain the position of the hallux on that foot, preventing gross hallux valgus (which, in turn, could predispose to development of a pressure area).

For the lateral three toes, virtually no functional loss is experienced with either partial amputation or disarticulation, and foot architecture is minimally disturbed.[11]

Dissection is carried down to the periosteum, and a bone cutter or pneumatic saw is used to perform the osteotomy at the appropriate level. It is important to be mindful of tendon insertions and to consider the biomechanical effects that sacrificing these will have; disruption may create a cycle whereby further surgical intervention will be needed.

Disarticulation of toe

Dissection is carried down to the joint capsule, the capsule is completely incised, and the distal segment is removed (see the images and the video below).

Toe excised. Note shiny cartilage cap on metatarsa Toe excised. Note shiny cartilage cap on metatarsal head.
Fourth metatarsal head cartilage. (For removal, se Fourth metatarsal head cartilage. (For removal, see video.)
Lateral two toes amputated. Note alternative techn Lateral two toes amputated. Note alternative technique used here. Single larger wound is made rather than two smaller fish-mouth wounds; this is because skin bridge between toes was unlikely to have adequate perfusion.
Amputation of adjacent toes at metatarsophalangeal joint using fish-mouth incisions.

Classically, a curette, a burr, or another instrument is then employed to remove the cartilage from the remaining joint surface (see the image below) as an aid to healing (because cartilage is avascular). However, some authors dispute the necessity of this measure.[12] After disarticulation of the great toe, suturing the long extensor tendons to the dorsal joint capsule will elevate the metatarsal head.

Metatarsal head cartilage removed. Metatarsal head cartilage removed.

Ray amputation

The operation is tailored to the burden of disease, ranging in extent from the removal of a single toe and its corresponding metatarsal to removal of the lateral four toes and their metatarsals. The latter amputation is functionally superior to a transmetatarsal amputation[12] and is preferable, provided that the hallux is free of disease.

Ray amputation of the hallux disrupts the medial column of the foot and should be performed only after careful consideration. The removal of a single metatarsal in the middle of the foot (ie, the second, third, or fourth metatarsal) results in a V-shaped wedge, which again maintains good function. However, because of the narrow forefoot that results from middle-ray amputation, shoe-fitting can be difficult, and forefoot equinus often develops.

Adequate skin and soft tissue for coverage can be obtained by removing an adequate amount of bone. Small case series have shown that primary closure with irrigation is better than leaving the wound open, even in the presence of infection.[12, 13]

Transmetatarsal amputation

When trauma, gangrene, or other pathology is confined to the toes and does not involve the web spaces or the forefoot, a transmetatarsal amputation is suitable (see the video below).[14] An osteotomy is performed through each of the metatarsal necks. The plantar surface of each is beveled or rounded to prevent a pressure area from forming.

Revision of transmetatarsal amputation.

Typically, a plantar flap is used to close the wound, and regular wound irrigation is recommended. In the presence of infection, the wound is left open to heal secondarily; if no infection is present, it is closed with nonabsorbable sutures.

A concomitant Achilles tendon–lengthening procedure may be required to achieve a neutral position of the shortened foot. The Hoke method of tendon lengthening can be performed as either an open or a closed technique.[15]

In a study comparing digital amputation (n = 77) with transmetatarsal amputation (n = 70) in 147 diabetic patients with gangrenous toes, Elsherif et al found that transmetatarsal amputation offered better outcomes, with a lower reintervention rate (15.7% vs 29.9%), a shorter median hospital stay (17 days vs 20 days), fewer theater trips, and a longer time without toxicity (346 days vs 315 days).[16] However, the differences did not reach statistical significance.

Complications

Complications of toe amputation include the following:

  • Inadequate hemostasis - This may necessitate a return to the operating room for ligation or cauterization of the responsible vessels; pressure bandages may be counterproductive, because they induce ischemia in the area
  • Hematoma - Undrained collections of fluid (including blood) are a nidus for infection and should be swiftly addressed
  • Proximal gangrene - This is caused by a mismatch between arterial supply and tissue demand and indicates inadequate amputation
  • Flap necrosis - This also reflects inadequate blood flow; it is worsened by any tension in the repair, which should be avoided
  • Failure to heal - This reflects inadequate blood supply as well; it may also be due to ongoing infection
  • Tetanus - This may result from failure to provide tetanus prophylaxis, particularly in trauma-related amputations
  • Phantom pain - This is unusual with toe amputations

In a study involving 10 elite alpinists who underwent digit amputation after sustaining freezing cold injury, Gorjanc et al found that amputated toes cooled much faster than their uninjured counterparts and reached lower skin temperatures during the cold exposure test, which suggests that amputated toes might be at greater risk for future freezing cold injury with subsequent cold exposures, as a consequence of less perfusion.[17]