Above-Knee (Transfemoral) Amputation - Full Detail

Definition & Overview

Levels of Transfemoral Amputation

• Campbell's Operative Orthopaedics 15th Ed 2026, p. 886
• Miller's Review of Orthopaedics 9th Edition, p. 875

Indications

1. Peripheral vascular disease (PVD) / ischemia - when ischemia extends too proximally for adequate soft tissue coverage of a below-knee stump
2. Diabetic foot gangrene with proximal spread - wet, dry, or gas gangrene not amenable to distal amputation
3. Failed below-knee amputation - wound breakdown, infection, or non-healing stump
4. Severe trauma with irreparable neurovascular injury, unsalvageable limb
5. Malignancy - soft tissue or bone tumors of the distal thigh/knee
6. Severe infection - osteomyelitis, necrotizing fasciitis, gas gangrene
7. Refractory infected total knee arthroplasty - when arthrodesis is not possible due to massive bone loss or life-threatening infection
8. Non-ambulatory patients with severe tissue loss - bed-bound patients where healing at a lower level is not feasible
9. Congenital deformity - when limb salvage is not functional

• Fischer's Mastery of Surgery 8th Ed, p. 6626-6627
• Current Surgical Therapy 14e, p. 1195

Contraindications / When to Choose a Lower Level

• Every centimeter of limb length preserved reduces energy expenditure of ambulation
• Patients with transfemoral amputations and PVD are unlikely to become efficient prosthetic walkers
• The energy cost of bilateral AKA prosthetic ambulation is 4-7 times normal oxygen consumption

• Causes minimal muscle transection and less intraoperative bleeding
• Preserves a longer lever arm for transfers
• Creates an end-weight-bearing stump
• Avoids knee flexion contracture seen at BKA level
• Reduces metabolic cost of ambulation compared with transfemoral amputation

Relevant Anatomy

Thigh Compartments (at AKA level)

• Bounded by lateral and anteromedial intermuscular septa (attached to fascia lata and linea aspera)
• Contains: quadriceps femoris (vastus lateralis, medialis, intermedius, rectus femoris), sartorius
• Innervated by the femoral nerve

• Contains: adductor longus, adductor brevis, adductor magnus, gracilis
• Innervated by the obturator nerve
• Contains the adductor canal (femoral artery, femoral vein, saphenous nerve/nerve to vastus medialis at mid-thigh and above)

• Contains: semimembranosus, semitendinosus, biceps femoris (long and short heads)
• Innervated by the sciatic nerve (posteromedial at distal thigh - may present as medial tibial nerve + lateral common peroneal nerve)
• At distal thigh: sciatic nerve is posterolateral to biceps femoris

• Greater saphenous vein runs from 8-10 cm posterior to medial patella toward pubic tubercle
• Large communicating branch between small and great saphenous veins may ascend around medial thigh
• Duplication of great saphenous vein may occur in distal thigh

• Thicker proximally and laterally (reinforced by iliotibial tract - tensor fascia lata + gluteus maximus)
• Reinforced distally by fibrous expansions from biceps femoris, sartorius, and quadriceps

• Superficial femoral artery and femoral vein travel between vastus medialis and sartorius
• At/above adductor hiatus: popliteal artery and vein encountered posteriorly
• Profunda femoris (deep femoral artery): terminal perforating branches posteromedial to femur; main terminal profunda may require suture ligation if SFA is occluded
• Fischer's Mastery of Surgery 8th Ed, p. 6657-6659

Preoperative Considerations

1. Vascular assessment - confirm level of viable tissue; Doppler/ABI, angiography if revascularization is possible
2. Nutritional optimization - albumin, pre-albumin; malnutrition impairs wound healing
3. Glycaemic control in diabetics
4. Antibiotic prophylaxis - for infection/gangrene cases
5. Assess rehabilitation potential - determines whether adductor myodesis (adds operative time) is worthwhile; not recommended for frail, elderly dysvascular patients unlikely to use a prosthesis
6. Patient counseling on prosthetics, rehabilitation, and energy demands
7. Tourniquet - can be used in nonischemic limbs; not appropriate in dysvascular disease

Surgical Technique (Transfemoral Amputation)

Patient Positioning

• Supine on the operating table
• Tourniquet applied proximally for non-ischemic limbs

Skin Incision - Fishmouth (Anterior and Posterior Flaps)

• Mark the distal aspect of the anterior flap ~2 cm proximal to the patella
• The corners (where the two flaps meet at 3 o'clock and 9 o'clock positions) are placed ~10 cm from the knee joint
• The femur will be transected approximately 12 cm from the knee joint

• The posterior flap can be made slightly longer (1-2 cm) if needed - particularly if the patient has a large lower extremity - to move the scar line away from the dependent/posterior position and to ensure tension-free closure
• In dysvascular patients: the femur may be transected as proximal as needed for skin closure (typically in the distal one-third of the femur, but more proximal if required)
• In ambulatory candidates: preserving maximum femoral length is the priority

Step-by-Step Operative Technique (Campbell's Technique 18.5)

1. Outline equal anterior and posterior skin flaps beginning proximally at the predicted bone section level. Each flap length should be at least one-half the anteroposterior diameter of the thigh at that level.
2. Fashion the anterior flap with an incision starting at the midpoint of the medial aspect of the thigh at the bone section level, curving distally and laterally across the anterior thigh, then curving proximally to the lateral aspect.
3. Fashion the posterior flap in a comparable manner.
4. Deepen skin incisions through subcutaneous tissue and deep fascia; reflect flaps proximally to the bone section level.
5. Divide the quadriceps muscle and overlying fascia along the anterior incision and reflect proximally as a myofascial flap. Leave the four muscle bellies at least three-quarters of the femoral diameter longer than the planned femoral transection level to support myodesis.
6. Be mindful of the greater saphenous vein medially - suture ligate it.
7. The superficial femoral artery and femoral vein are identified between the vastus medialis and sartorius and suture ligated separately. If the femoral artery is diseased or contains a stent, it can be divided with heavy scissors or wire cutters.
8. Identify and divide the saphenous nerve (or femoral nerve if proximal amputation) under tension.
9. Release posterior femoral attachments with electrocautery to prepare the posterior flap.
10. Clear the femur periosteum ~2 cm proximal to the flap corners (approximately 12 cm from knee joint) using a periosteal elevator.
11. Protect surrounding soft tissue with large skin hooks anteriorly and malleable retractors/laparotomy pad posteriorly.
12. Transect the femur with a power saw or Gigli saw.
13. Elevate the femur end with a bone hook and divide the posterior compartment muscles along the contour of the posterior incision using an amputation knife.
14. If medial hamstring myodesis is planned: leave medial hamstring long enough to cover the entire distal femur; otherwise leave both hamstrings ~three-quarters of the femoral diameter longer than the femur.
15. Ligate any arterial/large venous bleeding; secure muscular hemostasis.
16. Identify the sciatic nerve: place on tension, ligate proximally with absorbable suture, and sharply transect, allowing it to retract proximally (prevents painful neuroma at stump end).
17. Ligate the tertiary perforating branches of the deep femoral artery posteromedially; suture ligate the terminal profunda if well-developed.
18. Contour the femoral edges with a rasp or saw to smooth all sharp edges.

• Fischer's Mastery of Surgery 8th Ed, p. 6641-6644
• Sabiston Textbook of Surgery, p. 2345
• Campbell's Operative Orthopaedics 15th Ed 2026, p. 886

Adductor Myodesis (Key Step for Ambulatory Patients)

• Without myodesis of the adductor magnus, most transfemoral amputations result in at least 70% loss of adduction power
• The adductor magnus inserts at the adductor tubercle just proximal to the medial epicondyle; transecting it leaves the hip abductors unopposed, creating abduction deformity and inefficient widened gait
• Adductor myodesis maintains femoral adduction during stance phase, enabling optimal prosthetic function

1. Dissect the adductor muscle off its femoral attachment, preserving length
2. Drill four holes from the anterior midline to the lateral edge of the femur:
   • For right AKA: 12 o'clock, 10:45, 9:30, 8 o'clock positions
   • For left AKA: 12 o'clock, 1:15, 2:30, 4 o'clock positions
3. Pass three #2 Ticron sutures through the four holes
4. The lateral suture secures the adductor magnus to the femur
5. The anterior suture secures the medial hamstring
6. The anterolateral suture reinforces both adductor magnus and medial hamstring myodesis
7. Locking suture technique within muscle and tendon is preferred

• Miller's Review of Orthopaedics 9th Edition, p. 875
• Fischer's Mastery of Surgery 8th Ed, p. 6644

Wound Closure

1. Approximate the deep fascia of the distal anterior and posterior flaps with interrupted 2-0 Vicryl sutures over the femoral shaft (myoplasty layer)
2. Perform interrupted Vicryl sutures to fully approximate both fascial flaps
3. Close the skin with vertical mattress interrupted nylon sutures (or deep dermal absorbable sutures + staples)
4. A closed suction drain may be placed at the surgeon's discretion
5. Apply a gauze dressing with compression ace bandage

Nerve Handling - General Principles

• Put on tension before division
• Ligated proximally with absorbable suture (prevents neuroma formation)
• Sharply transected under tension, allowing the nerve to retract proximally

Postoperative Management

Dressing & Stump Care

• Elastic compression dressings may be suspended about the opposite iliac crest for suspension
• Rigid dressings are difficult to apply and maintain at transfemoral level

Complications to Monitor

1. Wound dehiscence/breakdown - most common complication, especially in dysvascular patients
2. Wound infection / hematoma - drained if needed; closed suction drain helps
3. Phantom limb pain - pain perceived in the amputated limb; common, managed with medications, mirror therapy, targeted muscle reinnervation (TMR)
4. Stump neuroma - from inadequate nerve retraction
5. Hip flexion contracture - major complication; mitigated by:
   • Hip extension exercises
   • Formal physical therapy
   • Prone positioning postoperatively
   • Avoiding prolonged sitting/wheelchair positioning
6. Abduction deformity - from inadequate adductor myodesis (unopposed abductors)
7. Skin breakdown over bony prominences - especially prominent distal femur if anterior femur not covered by soft tissue; adductor myodesis helps here
8. Reamputation - for non-healing or proximal spread of infection

Rehabilitation After Transfemoral Amputation

• Cardiac patients
• Patients with ischemic contralateral limbs
• Bilateral AKA patients (O₂ consumption is 4-7 times normal)

• Many transfemoral amputees with vascular disease never use a prosthesis consistently
• Patients with bilateral transfemoral amputations often choose wheelchair use for speed
• Younger patients with non-ischemic amputations progress more rapidly

Rehabilitation Protocol

Prosthetic Options

• Conventional constant-friction knee - extends 9-10 cm distal to socket end; requires femur transected ≥9-10 cm proximal to knee
• Computer-assisted (microprocessor) knee - uses hydraulic or magnetic units; sensitive sensors allow more natural knee motion, especially deceleration during swing phase; accommodates shorter distal femoral segments
• Osseointegrated implants - emerging technique for select transfemoral amputees
• Campbell's Operative Orthopaedics 15th Ed 2026, p. 886-888
• Miller's Review of Orthopaedics 9th Edition, p. 875

Special Situations

Guillotine Amputation (Emergency)

• Done as quickly as possible and as distally as possible
• Goal: remove necrotic/infected tissue rapidly without wound closure
• Bleeding vessels ligated; vacuum or gauze dressing placed
• This is temporary and lifesaving; formal amputation follows in days when the patient is stabilized

Cryoamputation (Critically Ill)

• A Styrofoam cooler filled with dry ice is placed around the infected extremity
• A warming pack is applied proximal to the cooler to protect proximal tissue
• Isolates infected limb from the circulation by extreme cold
• Bridge therapy until the patient is stable enough for formal OR amputation

Short Transfemoral Stump (<5 cm from lesser trochanter)

• Functions and is prosthetically fitted as a hip disarticulation
• Standard above-knee prosthesis cannot be effectively used

Comparison: AKA vs. Adjacent Levels

Sources

• Fischer's Mastery of Surgery 8th Ed, pp. 6626-6644 (detailed AKA surgical technique, anatomy, myodesis)
• Campbell's Operative Orthopaedics 15th Ed 2026, pp. 886-888 (technique 18.5, rehabilitation)
• Miller's Review of Orthopaedics 9th Edition, p. 875 (adductor myodesis, prosthetics)
• Sabiston Textbook of Surgery, p. 2345 (AKA principles)
• Current Surgical Therapy 14e, pp. 1195-1196 (transfemoral amputation, cryoamputation)