Amputation for Tumour (Forequarter, Hindquarter & Rotationplasty)

The shift to limb salvage. Historically amputation was the primary treatment for extremity sarcoma. Following the landmark work of Rosen and the introduction of neoadjuvant chemotherapy, plus the limb-salvage comparison studies of the 1980s, limb salvage has become the standard of care. - Limb salvage is now performed in roughly 85 to 90 percent of extremity sarcomas

• Amputation is required in only about 5 to 10 percent of cases
• Survival is equivalent between amputation and limb salvage when a wide margin is achievable - amputation does NOT improve cure rates
• Local recurrence rates are slightly higher with limb salvage than amputation, but with no survival penalty when recurrence is detected and managed early

Indications for amputation. The decision is reserved for the tumour, the limb or the patient in whom a wide margin and a useful limb cannot otherwise be achieved: - Major neurovascular encasement - tumour circumferentially involving the main artery, vein and nerve such that a wide margin cannot be achieved without sacrificing limb viability or function

• Extensive joint or multi-compartment involvement - disease crossing fascial planes into several compartments or into a joint
• Large recurrent tumour - particularly after previous surgery and radiotherapy where re-excision margins are inadequate
• Fungating or infected tumour - for local control, hygiene and palliation of symptoms
• Pathological fracture - when the fracture haematoma contaminates compartments beyond the resectable field
• Failed limb salvage - chronic deep infection of a megaprosthesis, failed reconstruction, or a non-functional salvaged limb
• Distal tumours where salvage is non-functional - reconstruction would leave a limb worse than a well-fitted prosthesis
• Informed patient preference - some patients choose a single definitive procedure over prolonged, multi-operation salvage
• Palliation - in advanced disease for a fungating, painful or haemorrhaging tumour, even in the presence of metastases, to improve quality of life Oncological principles of the amputation. Every amputation for tumour is planned and executed to oncological rules, not prosthetic convenience: - Plan from staging imaging - whole-bone MRI defines the proximal tumour edge and detects skip lesions (discontinuous intramedullary deposits). A bone cut must be made a safe distance proximal to all disease
• Wide margin - a continuous cuff of normal tissue around the tumour in every plane, including the bone marrow margin
• Marrow margin confirmation - frozen section of the divided bone end confirms tumour-free marrow before closure
• Excise the biopsy tract - the tract is contaminated and must be removed en bloc within the specimen
• Plan flaps from uninvolved tissue - use atypical or non-standard flaps if needed to keep the tumour margin wide. Oncology trumps the textbook flap
• MDT and neoadjuvant therapy - decisions are made within the sarcoma MDT; chemotherapy and radiotherapy status influence timing, flap choice and wound healing The decision in one table. Whether to amputate turns on whether a wide margin and a useful limb can be achieved another way:

Consent and preparation. Counsel specifically on the amputation level, phantom pain, the prosthetic plan and psychological support. For hindquarter and forequarter amputations carry major haemorrhage risk, so cross-match generously, plan for cell salvage and large-bore access, and involve vascular and general or urology surgery as needed for the proximal dissection. Re-mark the biopsy tract for en bloc excision and plan flaps from uninvolved tissue.

The goal is to remove the tumour-bearing segment with a continuous wide margin while achieving proximal vascular control before division, preserving a tumour-free marrow margin, excising the biopsy tract en bloc, and closing with viable soft tissue fashioned from uninvolved, non-irradiated tissue. The exposure and vascular control are the heart of each operation and are laid out step by step below.

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Energy expenditure rises with each more proximal level. A central principle is that the energy cost of walking rises - and prosthetic function falls - with each more proximal amputation level. This drives the surgical preference to preserve length and joints where oncologically safe, and underpins the case for rotationplasty in children.

Rehabilitation pathway. Recovery is structured around stump maturation, pain control and prosthetic fitting, tailored to the level: - Early - stump oedema control (compression), pain management (phantom and stump pain), wound care, early mobilisation and transfers

• Prosthetic phase - a preparatory prosthesis once the wound and stump volume stabilise, progressing to a definitive socket
• Upper limb (forequarter) - prosthetics are often largely cosmetic; many patients function well as one-handed with a lightweight cosmetic shoulder prosthesis. Functional myoelectric options exist but uptake at this level is limited
• Lower limb proximal (hindquarter) - a complex socket with hip and knee units; sitting balance and skin care over the resection are key challenges
• Rotationplasty - a custom prosthesis harnesses ankle motion as knee motion, and intensive physiotherapy teaches the patient to drive the new knee with ankle plantar and dorsiflexion Osseointegration. A transcutaneous bone-anchored implant is an emerging option for selected amputees, particularly transfemoral, who cannot tolerate a socket. Advantages are direct skeletal load transfer, osseoperception and no socket-related skin problems. In oncology it requires a disease-free status and intact host bone - infection at the skin-implant interface (stoma) is the principal concern, so selection and surveillance are essential. Psychological and survivorship support. Amputation for tumour combines limb loss with a cancer diagnosis, so structured psychological support, peer mentoring (including meeting prior rotationplasty patients and families) and long-term survivorship follow-up are integral, not optional. Complications. Recognise, prevent and manage the major complications of oncological amputation:

Prosthetic and rehabilitation priorities by level:

Epidemiology and the shift to limb salvage. Limb salvage is now the standard of care for extremity sarcoma, performed in roughly 85 to 90 percent of cases, with amputation reserved for about 5 to 10 percent. Following the landmark work of Rosen on neoadjuvant chemotherapy and the limb-salvage comparison studies of the 1980s, survival has been shown to be equivalent between amputation and limb salvage when a wide margin is achievable. Local recurrence rates are slightly higher with limb salvage, but with no survival penalty when recurrence is detected and managed early. Definitions and classification of the specific amputations. The level and extent of each operation is defined by what is removed and by whether a functional limb can be preserved: - Forequarter amputation (Berger) removes the entire upper limb together with the scapula and clavicle at the level of the root of the neck. Indicated for high-grade tumours of the proximal humerus, shoulder girdle or scapula not amenable to limb salvage, and for large or recurrent shoulder-girdle sarcomas.

• Tikhoff-Linberg resection is the limb-sparing en bloc removal of the proximal humerus, scapula and lateral clavicle, preserving a functional hand and forearm - the shoulder-girdle equivalent of internal hemipelvectomy.
• Hindquarter amputation (external hemipelvectomy) removes the entire lower limb together with the hemipelvis (innominate bone). The standard hindquarter divides through or near the sacroiliac joint and pubic symphysis; the extended hindquarter includes part of the sacrum for more medial disease; the conservative (modified) hindquarter preserves a portion of the iliac wing when oncologically safe, improving sitting balance. Indicated for high-grade sarcomas of the pelvis, hip or proximal thigh that cannot be cleared by internal hemipelvectomy.
• Internal hemipelvectomy is the limb-SPARING resection of part of the pelvis without amputating the lower limb (Enneking pelvic resection types I to III: ilium, periacetabular, ischiopubic).
• Transfemoral and transtibial amputation are used for thigh and leg tumours where a more distal limb-sparing option is not possible - again the level is set by tumour clearance and marrow margin, NOT by the classic prosthetic level. Van Nes rotationplasty — concept and why it is ideal in children. For paediatric distal femoral (or proximal tibial) sarcoma, the tumour-bearing segment is resected and the distal limb is rotated 180 degrees and reattached so that the ankle now functions as a knee joint - plantarflexion of the ankle produces extension of the new knee, and dorsiflexion produces flexion. Functionally it converts an above-knee-level resection into a below-knee-equivalent prosthetic limb. It is ideal in children because it grows with the child (retaining the proximal tibial physis, so there is no leg-length crisis), has no implant to revise, is durable and active (children can run, cycle and play sport, with energy expenditure approaching that of a below-knee amputee), and its main barrier is cosmetic and psychological acceptance - thorough counselling with families and prior rotationplasty patients is essential.