Amputation of the Lower Extremity: Above-Knee Amputation, Below-Knee Amputation, Through-Knee Amputation



Amputation of the Lower Extremity: Above-Knee Amputation, Below-Knee Amputation, Through-Knee Amputation


Anahita Dua

Jason T. Lee



INTRODUCTION



  • Approximately 1.7 million Americans are living with the loss of a limb, and this number is expected to nearly double by 2050.1


  • Amputations of the lower extremity may be performed for a myriad of reasons including infection, trauma, cancer, and pain.


  • Thoughtful patient selection, early involvement of neuropsychiatry, and physical medicine and rehabilitation (PM&R) are fundamental to a successful outcome.


APPROACH CONSIDERATIONS



  • Before considering an amputation, the patient should be evaluated by vascular surgery to ensure no other options (endovascular or open) exist.


  • Patients who are suited for an above-knee amputation (AKA) include those who have limited or no mobility, a nonfunctional limb, infection that has progressed above the knee, inadequate overlying skin/muscle to provide stump coverage, and those patients who do not have adequate blood flow to heal a below-knee amputation (BKA) incision (popliteal pressures less than 50 mm Hg).


  • BKA is suited in patients who wish to ambulate with a prosthesis, do not have extensive infection above the knee joint, and have popliteal pressures greater than 50 mm Hg to heal the stump.


  • Knee disarticulations (through-knee amputations) represent less than 2% of all amputations and are typically performed for trauma; they are best suited for patients who are unlikely to ambulate.


  • AKA is also suitable for patients unlikely to ambulate, but cannot be performed in patients with inadequate femoral artery blood flow as the AKA stump will not heal.


  • Severe infection that involves the femoral head or proximal femur also preclude AKA.2


PREOPERATIVE PLANNING



  • All patients undergoing an amputation should be evaluated early by both neuropsychiatry and PM&R.


  • Thorough physical exam and arterial pressures should be used to determine which level (AKA or BKA) is best for the patient (FIG 1).


  • Cardiac optimization is important given the high incidence of cardiac disease among this patient population.


  • If discussing limb viability status post trauma, a multidisciplinary approach involving vascular, orthopedic, and plastic surgery services should take place prior to proceeding with amputation.






FIG 1 • Incisions for above-knee (AKA), below-knee (BKA), and through-knee amputation.


Nov 24, 2019 | Posted by in Aesthetic plastic surgery | Comments Off on Amputation of the Lower Extremity: Above-Knee Amputation, Below-Knee Amputation, Through-Knee Amputation

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