Lower extremity amputation is performed to remove ischemic, infected, necrotic tissue, fracture, accidental removal of body parts, or locally unresectable tumor and, at times, is a life-saving procedure. Peripheral artery disease and diabetes mellitus, diabetic foot ulcers contribute to more than one-half of all amputations; trauma is the second leading cause worldwide. The second Trans-Atlantic Inter-Society Consensus Working Group (TASC II) documented that major amputations due to peripheral artery disease range from 12 to 50 per 100,000 individuals per year in the USA.
This incidence is directly proportional to rates of peripheral arterial occlusive disease, neuropathy, soft tissue sepsis, necrosis.[rx] This correlation is due to the increased incidence of diabetes mellitus, diabetic foot ulcers which are present in eighty-two percent of all vascular-related lower extremity amputations. Patients with diabetes mellitus have a 30 times greater lifetime risk of undergoing an amputation when compared to patients who do have no diabetes mellitus.[rx] [rx].[rx]
This activity will focus on amputations at the level of the femur and distally femur parts; it will cover above-knee, through-knee, and below-knee amputations. In addition, it will describe the technique for certain foot amputations (Syme, Chopart, Boyd), but the reader is encouraged to seek further in-depth text on these techniques. Amputations are procedures that are performed surgically although on rare occasions and limited settings can be performed employing amputation.[rx]
Anatomy and Physiology
The lower extremity is subdivided among the thigh (between the hip and knee joints), lower leg (between knee and ankle), and the foot (calcaneus and distally).
The thigh compartments and their contents are the followings
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Anterior compartment:
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Sartorius
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Quadriceps, composed of rectus femoris, vastus lateralis, vastus medius, and vastus intermedius.
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Superficial femoral artery and vein
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Medial compartment
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Adductor magnus muscle
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Gracilis muscle
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Deep femoral artery and vein
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Saphenous nerve
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Posterior compartment
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Biceps femoris muscle
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Semitendinosus muscle
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Semimembranosus muscle
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Sciatic nerve
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The great and small saphenous vein and nerve are located in the subcutaneous tissue of the medial thigh and run parallel to the intermuscular septum of the anterior and medial compartments.
The lower leg compartments and their contents are the following:
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Anterior compartment
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Tibialis anterior muscle
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Extensor hallucis longus muscle
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Extensor digitorum longus muscle
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Peroneus tertius muscle
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Anterior Tibial artery
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Anterior tibial vein
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Deep peroneal nerve
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Lateral compartment
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Peroneus brevis muscle
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Peroneus longus muscle
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Deep posterior compartment
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Tibialis posterior muscle
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Flexor digitorum longus muscle
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Flexor hallucis longus muscle
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Posterior tibial artery
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Posterior tibial vein
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Peroneal artery
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Peroneal vein
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Tibial nerve
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Superficial posterior compartment
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Soleus muscle
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Gastrocnemius muscle
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Plantaris muscle
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Sural cutaneous nerve
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*The lesser saphenous vein is located in the subcutaneous tissue of the posterior lower leg and runs parallel up to the sural nerve.
The foot is encomposed of seven tarsal bones, five metatarsals, and fourteen phalanges. It is subdivided among hindfoot (talus and calcaneus bones), midfoot (cuboid, navicular, three cuneiform bones), and forefoot (metatarsals and phalanges). The muscles of the foot can be extrinsic, intrinsic originating from the anterior, posterior aspect of the lower leg, intrinsic muscles, and originating from the foot.
Indications
Indications for amputation are related to the degree of tissue necrosis or apoptosis is viability, and it is performable in either a single operation or a staged system(amputation followed by reconstruction). The decision to take on depends largely on the clinical status of the patient and the quality of the soft tissues at the desired level of amputation with the primary goal being to excise or cut the non-viable and infected tissue. In general, soft tissue quality and the ability to obtain bone coverage will follow the adequacy of the level of amputation. It is important that skin grafts are an acceptable option for patients where adequate muscle coverage is visible, where skin coverage is not possible.
Patients with diabetes mellitus can present along with a group of diseases; from a non-healing foot wound with underlying osteomyelitis to a grossly infected wound leading to septic shock. In peripheral vascular disease, this decision to amputate is made with the appearance of non-healing tissues, or wounds when there are no options for the restoration of flow. In this case, patients can generally present in one of two ways in the acute setting with infected necrosis is present (‘wet gangrene’) leading to puss or with ischemic necrosis (‘dry gangrene’) where the tissue is necrotic without signs of systemic compromise.
Before deciding to amputate, it’s essential to optimize the patient from a medical standpoint. In patients with DM, all efforts should specialize in achieving adequate glycemic control and early antibiotic treatment to attenuate the danger of surgical site infection and to maximize the length of non-infected tissue, respectively. it’s reasonable to think about these patients’ candidates for one operation should the standard of the soft tissue allow it. within the patient presenting with septic shock, the choice to perform an open (guillotine) amputation with staged reconstruction versus one operation depends on the clinical status of the patient and therefore the primary goal should be to get adequate source control, leaving reconstruction for a later date. Patients presenting with signs of a systemic inflammatory response and extensive cellulitis may receive initial treatment with intravenous antibiotics. A decrease in cellulitis may leave a more distal level of amputation than anticipated also allowing the operator to require place during a single stage.
High-energy traumatic injuries can cause amputation at the instant of injury. Alternatively, patients can present to the hospital with a mangled extremity not amenable to reconstruction. Several scoring systems are often utilized to work out whether complex reconstruction options should be pursued. However, the first focus should have its basis on employing the Advanced Trauma Life Support protocol since it’s likely that patients present with concomitant life-threatening injuries. This includes assessment of bleeding from the wound, obtaining hemostasis, and performing adequate resuscitation. the extent of amputation will depend upon the viability of the soft tissues wont to obtain bone coverage.[rx] it’s important to notice that victims of severe traumatic lower extremity injury who initially were candidates for limb salvage may become candidates for an amputation thanks to infection, inability to get bone or hardware coverage, persistently high pain levels or lack the will to undergo lengthy reconstructive protocols for poor functional results.
Contraindications
Patients with advanced peripheral vascular disease often have diabetes, are elderly, and have multiple comorbidities with low physiologic reserve. it’s therefore ideal to medically optimize these patients before a definitive operation. However, an emergency lower extremity amputation could also be required to permit for clinical improvement, and therefore the risks of surgery anesthesia must be discussed with the patient and/or designated advocates.
Certain patients are within the medical care setting receiving vasoactive infusions and heavy sedation with low cardiopulmonary reserve. Amputation could also be indicated, but their critically ill state doesn’t leave such. it’s acceptable to attend for clinical optimization before performing an amputation. an alternative to the present is computation, which is the concept of refrigeration of unsalvageable ischemic limbs in critically ill patients. There are many described techniques which include the appliance of ice bags, drinking water immersion, mechanical refrigeration, and utilizing solid. Although cumbersome, it is often employed successfully with appropriate training of nursing staff and therefore the creation of institutional protocols. A subsequent formal amputation procedure can then follow once the metabolic derangements have resolved, and therefore the benefits of the surgery have surpassed the risks.
Equipment
The procedure will occur within the operating room during a sterile environment with the utilization of an appropriately sized tourniquet. The patient is within the supine position and under general anesthesia or regional blockade. Of note, some patients may haven’t any vascular inflow, and thus, a tourniquet isn’t necessary. However, careful consideration should focus the skin by covering it with a cotton roll or stockinette before application of a tourniquet.
A ruler and marking pen are wont to demarcate the skin incision and therefore the respective soft tissue flap. an outsized 15 or 20 blade are often wont to incise the skin and soft tissues. Alternatively, electrocautery is an option for the soft tissues and therefore the entire dissection with fresh blades reserved for nerve transection.
A Gigli saw or an influence saw is employed for transecting the bones. the facility saw also can be utilized to melt the sides of the bone once transected. Alternatively, bone rasper is often used and allows for more control and possibly smoother curvature of the anterior surface of the bone. A drill, a 2.0 mm drilling bit, and fiber wire suture are used if performing a modest. The tissue is closed layers.
Dressing materials can include petroleum gauze, soft rolls, army battle dressings, and a bandage for compression.
Personnel
Every team performing a lower extremity amputation must include an OR nurse, a scrub technologist, a surgical assistant, and an anesthesiologist. Post-anesthetic care unit staff is typically comprised of nurses and anesthesiologists or intensivists and are vital within the care of the patient within the immediate postoperative period. Face-to-face communication from the surgery team is obligatory during patient hand-off this is often a chance to speak a summary of the patient and therefore the reason for the operation performed. It also allows the surgeon to speak adversities encountered during the case, report on estimated blood loss and discuss resuscitative measures used intra-operatively which will need continuation within the immediate post-operative setting. it’s also important to speak about the sort of hospital unit the patient will attend thereafter and therefore the need for post-operative laboratory values.
Preparation
The most important part of the preparation, after medical optimization, is determining the extent of amputation. Transcutaneous oxygen tension (TcPO2) may be a measure of oxygen tension within the skin derived from the local capillary blood perfusion. This has been utilized as a tool to work out the extent of amputation in ischaemic limbs which demonstrated that patients with primary healing of postoperative wounds had significantly higher values of TcPO2 than patients with failure to heal (37 mmHg; range 15 to 56 mmHg vs. 18 mmHg; range 8 to 36 mmHg, p
Technique
The use of general anesthesia (GA) versus regional anesthesia (RA) for performing major lower extremity amputation is a neighborhood of ongoing process to support the utilization of RA for major lower extremity amputation with decreased blood loss, need for transfusion, postoperative pain medication, and faster time to oral intake in comparison with the overall anesthesia group.[rx] Another study showed there was no difference in postoperative myocardial infarct or mortality between GA and RA.[rx] More recently, the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was utilized to work out the effect of anesthesia type on major lower extremity amputation outcomes in functionally impaired elderly patients.[rx] They reviewed over 3000 patients over eight years. Fifty-nine percent underwent above-the-knee amputations, and therefore the remainder were below-the-knee. Patients undergoing GA were more apt to possess impaired sensorium, get on anticoagulation, or have a bleeding disorder and had a previous operation within 30 days. GA correlated with shorter anesthesia time to surgery but equivalent operative times in comparison to RA. There was no difference with regards to postoperative myocardial infarction/cardiac arrest, pulmonary complications, stroke, tract infections, and wound complications. Therefore, the choice about which anesthesia type to use should be performed on a case-by-case basis and collectively between the patient, surgeon, and anesthesiologist.
There are several components within the preparation of the patient within the OR which apply to all or any amputation levels. The patient should be within the supine position with appropriate use of tourniquet as this has shown to scale back blood loss during lower extremity amputation within the setting of peripheral artery disease.[rx] Preparation of the skin should be performed circumferentially and as proximal because of the groin. Skin preparation products include those containing iodophors or chlorhexidine gluconate, both of which are acceptable options.[rx] within the setting of diabetic foot wounds or gangrene, we recommend maintaining the wound covered with a dry dressing also as covering the affected foot with a sterile impermeable stockinette. An occlusive adhesive dressing are often utilized to make a seal and further isolate this from the incision site.
Principles of amputation surgery at any level includes: removal of diseased tissue, providing a residual limb that permits for prosthetic fit, tapering the ends of bone to avoid sharp edges, providing a conical shaped limb to permit better prosthetic fit, controlling postsurgical edema, avoiding hematoma formation, allowing nerve retraction, preservation of length and optimized postoperative pain control.[rx
The critical steps in surgical technique for several amputations levels are going to be discussed so as of proximal to distal.
Above-knee amputation
- The anterior and posterior flaps should be marked before incision to resemble an ellipse or fishmouth. it’s useful to live the circumference and mark the apices equally. If length isn’t a problem, the tip of the anterior flap should reach the sting of the patella with a reflection posterior flap.
- Tourniquet and Esmark bandage is employed . An incision is carried through the fascia, and therefore the anterior musculatures are divided with cautery.
- The muscle gets divided to the extent of the femur, and therefore the periosteum is elevated from the femur circumferentially to the extent of the incision apex.
- An oscillating saw or Gigli saw is employed to divide the femur. The adductor tendon is separated separately from the medial epicondyle and distal femur; this might be preserved to be used during a modest the sides are then rasped smooth.
- The artery of the femoralis and vena femoralis artery is clamped and suture ligated with heavy suture.
- The saphenous nerve should be dissected as proximally as possible and divided on tension it’s this author’s opinion that avoiding ligation helps avoid foreign body reactions and future neuroma formation. The nerve should retract 5 cm to 10 cm.
- If performing a myodesis (preferred by this author), a 2 mm drilling bit is employed to form a medial and lateral osteotomy on the distal femur.
- The preserved adductor tendon is then secured to the osteotomies medially and laterally with heavy non-absorbable fiber-wire or braided nylon suture.
- If the medullary canal remains open, the elevated periosteum is often reapproximated at now with a heavy absorbable suture.
- The posterior tissue then gets divided with an amputation knife or cautery.
- The sciatic/tibial nerve is now divided and allowed to retract as above
- The tourniquet is released, and every one bleeding ligated.
- A subfascial drain is left in situ if needed but generally unnecessary.
- The anterior and posterior flap is reapproximated with an important absorbable suture at the fascia.
- Skin and subcutaneous tissues closed layers.
Through-knee amputation
- An elliptical incision almost like the above-knee is formed with the apices at the medial and lateral epicondyles near the highest of the patella if a line were extended around the femur. The anterior flap distal margin extends to the tibial tuberosity. The posterior flap should plan to mirror the anterior flap.
- A tourniquet is employed as above. The surgeon employs an identical technique through the fascia as above.
- The patellar tendon is detached from the tibia, and therefore the surgeon enters the knee .
- The joint capsule is incised circumferentially and therefore the cruciate ligaments are divided from within the knee.
- Before dividing the posterior joint capsule and posterior tissues, it’s useful to spot the semitendinosus medially and therefore the biceps femoris laterally because they insert into the tibia posteriorly. they ought to be held with a Kocher clamp to stop retraction.
- Popliteal artery and vein individually suture ligated.
- The common peroneal and tibial nerves are divided under tension and transected sharply to permit retraction.
- The posterior tissues get divided with an amputation knife or cautery. It’s not necessary to preserve any gastrocnemius. The specimen is removed now.
- An oscillating saw is employed to form six osteotomies removing all of the articular surfaces while preserving the bulk of the adductor insertion medially; this may be cancellous bone with no medullary canal.
- The patella is then everted and far away from the inner surface of the patellar tendon taking care to not injure the skinny skin from the bare area within the mid-tendon.
- The tourniquet is released and further hemostasis is achieved with ligatures.
- Myodesis then follows by suturing the semitendinosus and biceps to the cruciate remnant posteriorly and therefore the patellar tendon to the cruciate anteriorly. This process is performed with heavy fiber-wire or braided nylon.
- Fascia, subcutaneous tissue, and therefore the skin closed as above.
Open below-knee amputation
This procedure is performed as distal because the soft tissues allow and may happen expeditiously with a Gigli saw through all structures followed by suture ligation of vascular structures. The residual limb is roofed with wet to dry dressings once hemostasis obtained.
The alternative is to use a scalpel and electrocautery for the skin, subcutaneous tissue, and muscle followed by isolation and control of vascular bundles. an influence saw or an equivalent Gigli saw is often used for bone. The residual limb is roofed with wet to dry dressings upon achieving hemostasis.
Formal below-knee amputation
- The level selected depends largely on soft tissue viability with the perfect length being approximately 12 to 18 cm from the tibial tubercle.[rx]
- It is useful to possess a typical technique to work out skin flaps. This author prefers to live the diameter at the transection site and make the anterior flap one-half the circumference and therefore the posterior long flap’s full circumference; this prevents unnecessary tension at the time of closure. Additionally, longer residual limb lengths typically involve a smaller circumference and thereby have less chance for tension.
- The incisions are carried through the skin, subcutaneous tissue, and anterior muscle with suture ligation of vasculature identified.
The tibial bone gets transected with an influence saw, or Gigli saw and tibial edges blunted with the use of a rasper the facility saw or rasper is often won’t to bevel the anterior aspect of the tibia. This process allows for fewer trauma to the posterior flap because it sits along a smooth surface. - The fibula gets transacted within the same manner at approximately 1 cm proximal to the tibial transaction and sharp edges removed with rasper, giving the residual limb a cornified aspect.
- The posterior tissue is split with an amputation knife leaving only a thinned portion of the soleus but preserving the gastrocnemius.
- At now ligation of anterior tibial, posterior tibial, and peroneal arteries are confirmed before the tourniquet is released. The tibial, deep and superficial peroneal, and soleus nerves divide on tension.
- The myodesis is performed by bringing the Achilles tendon to the tibia. Three osteotomies are created with a 2 mm drilling bit within the anterior portion of the tibia. Fiber-wire or heavy braided nylon is employed to secure the Achilles to the tibia utilizing the three osteotomies during a mattress fashion.
Skin and subcutaneous tissues closed layers.
ERTL amputation
- All steps are almost like formal below-knee amputation except a keyhole incision is employed extending just lateral to the tibial distally then round the ankle. The tibialis anticus muscle is preserved within the anterior compartment.
- An osteal periosteal graft is raised employing a hammer and chisel and left attached to the tibia anteriorly.
- The fibula is transected at an equivalent length because of the tibia. Soleus muscle and anterolateral compartment muscle are transected.
- A GIA stapler is beneficial for these Vascular bundles and nerves receiving similar treatment.
- A portion of the fibula is trimmed to make a strut between the tibia and fibula, which gets secured with a tightrope device, plate, or headless screw. The periosteal graft is secure round the fibula strut to assist in ossification
- Tibialis anterior is secured over the strut followed by the Achilles myodesis (pants over vest).
The closure begins anteriorly, and therefore the skin and subcutaneous tissue resected because the closure proceeds posteriorly
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Syme amputation
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A weight-bearing amputation through the ankle involves removal of all of the bones of the foot while preserving the heel pad for weight-bearing
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Boyd amputation
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A weight-bearing amputation through the ankle that preserves the calcaneus and heel pad for weight-bearing.
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The calcaneus gets fused to the tibia and is non-mobile
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Chopart amputation
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A weight-bearing amputation at the midtarsal level preserves the additional length of the foot
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Complications
- Lower extremity amputations involve significant peri-operative morbidity and mortality. Thirty-day postoperative mortality rates can range from 4% to 22%.[rx] .[rx] Mortality rates in diabetic lower extremity amputation patients can be as high as 77% at 5 years.[rx]
- Risk factors for death in the perioperative setting include AKA, postoperative cardiac complications, acute renal failure.[rx] A review of 2879 amputees demonstrated the most common post-surgical complications included pneumonia (22%), acute kidney injury (15%), deep venous thrombosis (15%), acute lung injury/acute respiratory distress syndrome (13%), osteomyelitis (3%) and flap failure (6%).[rx]
- Wound complications, which include dehiscence, seroma, hematoma, can occur in 12% to 34% of BKA patients and 6% to 16% of AKA patients.[rx] Risk factors for wound complications include sepsis, compartment syndrome, end-stage renal disease, ongoing tobacco use, body mass index over 30 kg/m2, and BKA.[rx] A retrospective study showed that the use of incisional negative pressure wound therapy (NPWT) in major limb amputation and revision amputation had a demonstrable benefit in decreasing the risk of wound complications.[rx]
- Phantom limb pain (PLP) is the pain that persists after complete tissue healing and is characterized by dysesthesia at the level of the absent limb. Patients describe this pain as burning, throbbing, stabbing, sharp as well as the sensation that the amputated limb is in an abnormal position.[rx] This pain can be present in 67% of patients at six months and 50% of patients at five to seven years.[rx][rx] There are several risk factors for developing PLP, which include: the presence of pre-amputation pain, female gender, upper extremity amputations, and bilateral amputations of the upper and/or lower extremities.[rx] A multidisciplinary approach that includes surgical technique, regional analgesia, pharmacological agents, physical therapy and psychotherapy are all key components in the peri-operative care of an amputee that can have a strong impact in decreasing the risk of PLP.
- Revision amputation procedures can occur in as many as 42% of patients who underwent a below-knee amputation secondary to trauma. Additionally, up to 13% of patients undergo revision to a higher level of amputation. Age, presence of a crush injury, compartment syndrome, and experiencing a major post-surgical complication were significant risk factors of revision amputation.[rx]
- It is also important to include psychological trauma as a complication of limb loss. A recent review performed by Mckechnie et al. reveals that depression can occur in 20.6 to 63% of patients (3 times higher than the general population) and anxiety in 25% to 57% (approximately the same as the general population) with 83% of patients attending a psychiatric clinic at one point after their surgery.[rx] Darnall et al. demonstrated an increased risk of depressive symptoms in patients undergoing an amputation secondary to trauma versus vascular disease or cancer.[rx] Current research, such as “Amputees Unanimous: A 12-step program”, is focusing on a multimodal approach toward the care of an amputee which aims to provide encouragement, support, and optimism for the future.[rx] Further research is needed to determine their impact on this patient population.
