Levels of Amputation in the Lower Limb

1. Ray Amputation

• The incision passes through the metatarsal shaft or at the metatarso-phalangeal (MTP) joint level.
• One or more "rays" (toe + metatarsal unit) are excised while leaving the remaining foot intact.
• Most commonly performed for diabetic foot infections, osteomyelitis, or gangrene limited to a single toe and its metatarsal.

2. Transmetatarsal Amputation (TMA) — Gillies

• The bone cut is made through the mid-shafts of the metatarsals (across all 5).
• The plantar flap is longer than the dorsal flap to allow cushioned weight-bearing over the stump.
• Preserves a functional, plantargrade foot stump.

3. Tarsometatarsal Amputation — Lisfranc's

• The amputation passes through the Lisfranc joint complex, which is the articulation between the bases of all 5 metatarsals and the three cuneiforms + cuboid.
• All metatarsals are removed; the tarsal bones (cuneiforms, cuboid, navicular, calcaneus, talus) are retained.
• The stump is at the level of the midfoot/tarsus.

4. Midtarsal Amputation — Chopart's

• The cut passes through the transverse tarsal joint — between the talus + calcaneus (posteriorly) and the navicular + cuboid (anteriorly).
• Only the calcaneus and talus are retained; everything anterior (navicular, cuboid, cuneiforms, metatarsals, toes) is removed.
• Risk of equinus deformity due to Achilles tendon pull on the retained calcaneus/talus without the anterior muscle counterbalance — often requires tendon lengthening.

5. Syme's Amputation

• Disarticulation occurs at the ankle joint (tibiotalar joint).
• The distal tibia and fibula are trimmed of their malleoli.
• The heel pad (calcaneal fat pad with its skin) is preserved and sutured over the bone ends — this is critical as it allows the patient to bear weight directly on the stump, even without a prosthesis.
• Named after James Syme (19th-century Scottish surgeon).
• Results in a long below-knee stump with excellent weight-bearing capability.

6. Below-Knee (Transtibial) Amputation — Burgess

• The standard level is approximately 10–15 cm below the tibial tuberosity (roughly the junction of the proximal and middle thirds of the tibia).
• The Burgess technique uses a long posterior myocutaneous flap from the gastrocnemius/soleus muscles to pad the bone end — providing better soft tissue coverage and improved prosthetic fitting.
• The fibula is cut slightly shorter (~1–2 cm) than the tibia.
• Preserving the knee joint dramatically improves prosthetic function and mobility.

7. Transcondylar (Through-Knee) Amputation — Gritti-Stokes

• The Gritti-Stokes variant: the femur is transected through or just above the femoral condyles (supracondylar level), and the patella is preserved and fused to the femoral stump (patelloplasty) to provide end-bearing.
• The knee joint is disarticulated or the femur is cut just proximal to the condyles.
• Results in a long femoral stump — good for end-bearing but may be difficult to fit a prosthetic knee unit due to the length.
• Done when below-knee amputation is not feasible but above-knee is not yet required.

8. Above-Knee (Transfemoral) Amputation

• Typically through the middle third of the femur, ideally leaving the stump at least 10 cm above the knee joint line.
• The longer the femoral stump, the better the lever arm for prosthetic control — but enough room must be left for a prosthetic knee unit.
• Standard technique involves myodesis (suturing muscles to bone) or myoplasty to balance the stump and prevent flexion-abduction deformity from unopposed iliopsoas and hip abductors.

Summary Table

Levels of Amputation in the Lower Limb — Fig. 21.6

1. Ray Amputation

• The incision is made around the affected toe and carried proximally along the metatarsal shaft.
• The metatarsal is divided at its base or mid-shaft, and the entire ray (metatarsal + all phalanges) is excised.
• The remaining metatarsals are left intact.
• Most common for diabetic foot osteomyelitis, gangrene, or tumors limited to a single ray.

2. Transmetatarsal Amputation (TMA) — Gillies

• Bone cuts are made through the mid-shafts of all 5 metatarsals simultaneously.
• A long plantar skin flap is fashioned (longer than the dorsal flap) to cover the stump — this provides a durable, well-padded weight-bearing surface.
• The fibula-like taper at each metatarsal stump end is bevelled to avoid pressure points.
• The ankle joint and all tarsal bones are fully preserved.

3. Tarsometatarsal Amputation — Lisfranc's

• All 5 metatarsals are disarticulated from the tarsus at the Lisfranc joint line.
• The 3 cuneiforms, cuboid, navicular, talus, and calcaneus are all retained.
• The stump ends at the midfoot level.
• The 2nd metatarsal base locks into a mortise between the cuneiforms — the surgeon must carefully release this during disarticulation.

4. Midtarsal Amputation — Chopart's

• The surgical cut passes through the joint between:
  • Talus → Navicular (medially)
  • Calcaneus → Cuboid (laterally)
• Everything anterior to this line (navicular, cuboid, cuneiforms, metatarsals, toes) is removed.
• Only the talus and calcaneus are retained.
• Risk: unopposed Achilles tendon causes equinus deformity — so Achilles tendon lengthening or tenotomy is often performed simultaneously.

5. Syme's Amputation

• Disarticulation at the tibiotalar (ankle) joint.
• The malleoli (medial and lateral projections of tibia and fibula) are trimmed flush with the joint surface to create a smooth, broad bone end.
• The calcaneal fat pad (heel pad) — with its overlying skin — is carefully dissected free from the calcaneus and rotated anteriorly to cover the bone ends.
• This heel pad is uniquely durable and allows the patient to bear weight directly on the stump tip, sometimes without a prosthesis.
• Results in the longest possible below-knee stump length.

6. Below-Knee (Transtibial) Amputation — Burgess Technique

• Standard bone division: 8–15 cm below the tibial tuberosity (roughly the junction of the proximal and middle thirds of the leg).
• The Burgess long posterior flap technique:
  • A long posterior myocutaneous flap of gastrocnemius/soleus muscle + overlying skin is preserved.
  • This flap is folded anteriorly over the bone ends, providing well-vascularised, padded stump coverage.
• The fibula is cut 1–2 cm shorter than the tibia.
• The anterior tibial crest is bevelled to prevent a sharp pressure point under the prosthetic socket.
• Preserving the knee is critical — below-knee amputees walk with ~25% extra energy expenditure vs. ~65% extra for above-knee amputees.

7. Transcondylar / Through-Knee Amputation — Gritti-Stokes

• In the Gritti-Stokes variant:
  • The femur is divided just above (supracondylar level) or through the condyles.
  • The patella is preserved, its cartilage is removed, and it is sutured to the cut surface of the femoral stump (patellodesis) — providing a broad, end-bearing stump surface.
• In simple through-knee disarticulation, the femoral condyles are retained without patellodesis.
• Advantage: long lever arm; good proprioception; no muscle cutting across bone (disarticulation preserves soft tissue).
• Disadvantage: the wide condylar stump is bulky and makes fitting a prosthetic knee unit difficult.

8. Above-Knee (Transfemoral) Amputation

• Bone division through the middle third of the femur, ideally leaving a stump ≥10 cm proximal to the knee joint line to allow fitting of a prosthetic knee unit.
• Myodesis (suturing muscle directly to bone through drill holes) or myoplasty (muscle to muscle) is performed to:
  • Provide soft tissue padding over the bone end.
  • Balance the stump — preventing flexion-abduction deformity caused by unopposed iliopsoas (hip flexor) and hip abductors pulling the femur.
• The longer the femoral stump, the better the prosthetic control — but at least 5–7 cm of femur below the lesser trochanter must remain.

Summary Table

Key Principle: Every level of amputation saved preserves function. The knee joint is the single most important landmark — its preservation dramatically reduces energy cost of walking and improves prosthetic outcomes.