Upper Limb Amputation

Upper limb amputation is the surgical removal of part or all of the upper extremity. Unlike lower limb amputation where weight-bearing function is paramount, upper limb amputation surgery must prioritize preservation of sensation and fine motor function to maximize hand utility.

Epidemiology:

• Upper limb amputations are approximately 5 times less common than lower limb
• Trauma is the most common indication (80%) - industrial accidents, motor vehicle trauma
• Males predominate (3:1 ratio) due to occupational exposure
• Mean age is younger than lower limb amputees (occupational injury)
• Finger and partial hand amputations are most common

Indications:

Contraindications to Replantation (Favour Amputation):

• Multi-level or avulsion injury (poor prognosis)
• Severe crush injury with tissue destruction
• Warm ischaemia time greater than 6 hours for digits (12 hours if cooled)
• Life-threatening associated injuries requiring resuscitation
• Severe medical comorbidities precluding prolonged surgery
• Self-inflicted injuries (relative - psychiatric assessment needed)

Functional Anatomy Considerations

Understanding the functional requirements at each level is essential for amputation planning in the upper limb.

Nerve Handling and Neuroma Prevention

Neuroma Formation:

• Inevitable after nerve transection - regenerating axons form disorganized mass
• Painful neuroma develops when nerve end is in mobile or pressure-bearing area
• Upper limb neuromas are particularly problematic due to constant use
• Prevention is key - proper nerve management at initial surgery

Targeted Muscle Reinnervation (TMR):

TMR Nerve Transfers by Level:

• Transradial: Median and ulnar nerves to remaining forearm muscle motor points
• Transhumeral: Median to short head biceps, ulnar to brachialis, radial to lateral triceps
• Shoulder: Musculocutaneous to clavicular pectoralis major, median/ulnar to sternal pectoralis

Phantom Limb Phenomena

Indications by Level

Replantation Decision-Making

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Prosthetic Options by Level

Body-Powered vs Myoelectric Prostheses

The topic repeatedly stresses that sensation is prized over length, that roughly a third of upper-limb amputees reject prostheses and adapt without them, and that limited-resource settings rely on function rather than technology - but it never mentions the one operation that delivers sensate prehension without any prosthesis: the Krukenberg procedure.

• What it is. A kineplastic (cineplastic) reconstruction of the transradial stump that splits the residual forearm into two sensate, independently mobile "pincers" - a radial ray (radius and its muscles) and an ulnar ray (ulna and its muscles) - separated down the interosseous space, with the pronator teres and other forearm muscles powering the opening and closing of the pincers.
• Why it is unique. The pincer tips are covered by the patient's own sensate skin, so grasp has intact sensation and proprioception that no prosthesis provides - the very qualities this topic says matter most in the upper limb. It is self-powered and self-suspending: no socket, battery, harness or maintenance.
• Who it is for. Classically the bilateral transradial amputee (on at least one side), the blind amputee (sensate grasp substitutes for lost vision), and low-resource settings where durable prostheses are unavailable. It needs an adequate residual forearm length and good soft tissue.
• The trade-off. The result is cosmetically confronting (a "lobster-claw" forearm), which limits acceptance for many patients; it can still be fitted with a prosthesis over it if desired, so it does not preclude later prosthetic use. Consider it when function without technology is the priority, not as a routine primary amputation.

The single most-repeated message in this topic is that the thumb is worth roughly half of hand function and should be replanted "at all costs", and "failed replantation" is listed as an indication for amputation - yet the topic never says what to do when the thumb is lost or unreplantable: reconstruct it.

• Why reconstruct at all. A hand without a thumb loses opposition, pinch and most grip; restoring even a mobile, sensate post to oppose against transforms function - so an unreplantable thumb is not simply "closed" but reconstructed up a ladder according to the level of loss and the available donors.
• Pollicization. For loss at or proximal to the metacarpophalangeal level (or a congenitally absent thumb), an adjacent digit - usually the index (or an already-injured, stiff finger) - is transposed onto the thumb axis, shortened and rotated into roughly 40-50 degrees of pronation/opposition with its intrinsics re-tensioned, converting a finger into a thumb in a single-stage, non-microsurgical operation that brings its own nerves and vessels.
• Microvascular toe-to-thumb transfer. When the other digits must be preserved, a free toe transfer (great toe, second toe, or a "wrap-around" great-toe flap) reconstructs the thumb with a growing, sensate, mobile digit and a nail - the workhorse for the amputated thumb on an otherwise healthy hand, at the cost of microsurgery and donor-foot morbidity.
• Simpler options. For lesser loss, length and stability are restored by distraction lengthening of the metacarpal, deepening of the first web space (Z-plasty/release), or osteoplastic reconstruction - lower-tech steps on the same ladder.

Global Epidemiology

• Upper-limb amputation is roughly 5 times less common than lower-limb amputation; in high-income settings the leading cause is trauma (occupational and machinery injury), whereas dysvascular and diabetic causes dominate the lower limb.
• Male predominance (~3:1) and a younger mean age than lower-limb amputees, reflecting occupational mechanism.
• In low- and middle-income countries, agricultural and industrial machinery, road trauma and conflict/blast injury are major contributors, often with delayed presentation that reduces replantation viability.

Guidelines and Society Guidance (side by side)

Registry and Outcome Data

• Upper-limb amputation and replantation lack the mature implant registries that exist for arthroplasty (NJR, AJRR, AOANJRR); evidence comes mainly from national administrative databases and large single-centre series (e.g. replantation volume-outcome relationships).
• Volume matters: higher institutional replantation volume is associated with higher digit-survival rates, supporting regionalised referral to specialist units.
• Emerging osseointegration outcome registries are beginning to capture infection and implant-survival data for bone-anchored upper-limb prostheses.

High- vs Limited-Resource Practice Variation

• High-resource: 24/7 microsurgical replantation, multi-articulating myoelectric hands, TMR/RPNI and osseointegration available in tertiary centres; structured limb-loss rehabilitation and peer support.
• Limited-resource: emphasis on durable revision amputation, sensate length preservation and robust body-powered or appropriate-technology prostheses; replantation reserved for the highest-yield cases (thumb, multiple digits) where microsurgical capacity exists.
• The functional priority (sensation greater than motion greater than length) and the imperative to preserve the elbow hold across all settings - they are decisions, not resources.