Elbow Amputations
Elbow disarticulation
When the elbow joint must be sacrificed, an elbow disarticulation is preferable to a more proximal amputation. Not only is greater length preserved, but also the broad flare of the remaining humeral condyles enhances prosthetic fitting and allows humeral rotation to be transmitted to the prosthesis.
Equal anterior and posterior skin flaps are created, beginning at the level of the humeral epicondyles. The incisions are extended distally 3 cm distal to the tip of the olecranon posteriorly and to a point just distal to the insertion of the biceps tendon anteriorly. The lacertus fibrosus is identified and divided, which allows the flexor-pronator origin to be freed from the medial epicondyle and exposes the neurovascular bundle underneath.
The brachial artery is isolated, doubly ligated, and divided proximal to the joint line. Located medial to the brachial artery, the median nerve is drawn distally, transected as proximally as possible, and allowed to retract into the proximal wound.
The ulnar nerve is identified posterior to the medial epicondyle and is transected in a similar manner. The biceps and brachialis tendons are freed from their insertions on the radius and ulna, respectively. Within the interval between the brachialis and brachioradialis, the radial nerve is identified and transected (as above).
The extensor musculature is divided transversely, approximately 7 cm distal to the joint line. Although the skin flaps are approximately equal, the posterior muscle flap remains longer than the anterior muscle flap so that it can wrap around and cushion the end of the humerus.
To complete the disarticulation, the anterior capsule and posterior fascia near the level of the olecranon tip are divided, the radiohumeral and ulnohumeral capsules are divided posteriorly, and the forearm is removed. The articular surface of the humerus is left intact.
The posterior flap should be carried medially and anchored to the remaining soft tissues on the medial epicondyle. Additional sutures are placed through the muscle flap and adjacent periosteum, so that all bony prominences and exposed tendons at the end of the humerus are covered. In patients with very little subcutaneous tissue and muscle, covering the end of the humerus with a reflected flap of brachialis, biceps, or triceps may be advisable.
Because of the flare of the humeral condyles, the distal stump should be expected to be somewhat more bulbous than it is for amputations above the elbow.
An article from Brazil suggested a surgical procedure by which electric elbow prostheses are fitted to an elbow disarticulation. [15] Normally, the bulky motor hangs several centimeters below the contralateral elbow, causing a cosmetic problem. The authors suggested a shortening osteotomy through the supracondylar area, thus accommodating the prosthetic motor and preserving the condylar flares.
Transcondylar amputations
Amputations at this level function prosthetically as elbow disarticulations. Depending on the precise level, some portion of the lateral epicondyle with its attached posterior flap may be preserved. If the lateral epicondyle and posterior flap are otherwise compromised, closure over the humerus must be accomplished by means of techniques described for amputations at the supracondylar level (see Above-Elbow Amputations below). However, this coverage should not affect the prosthetic function as long as some remnant of the condylar flare is preserved.
Above-Elbow Amputations
Supracondylar amputations
Amputations at or proximal to the supracondylar level define the distal extent of above-elbow amputations. Amputations distal to the supracondylar area, such as the transcondylar amputation, function as elbow disarticulations and are prosthetically fitted as such (see Elbow Amputations above). Without the presence of the humeral condylar flare, the prosthesis must contain an elbow-lock mechanism and an elbow turntable to allow prosthetic joint stability and rotation, respectively.
As with all amputations, length should be preserved as much as possible. However, the necessary prosthetic elbow-lock mechanism extends approximately 4 cm distally from the end of the prosthetic socket and, to be cosmetically appealing, should lie at a level equal to that of the contralateral elbow. Therefore, bone sectioning at the supracondylar level and above should be at least 4 cm proximal to the elbow joint to allow room for this mechanism.
Anterior and posterior skin flaps are extended equally. Neurovascular structures are identified and are divided as described for elbow disarticulations. Muscles in the anterior compartment of the arm are transected 2 cm distal to the intended level of bone section. The triceps insertion is freed from the olecranon, with the triceps fascia and muscle preserved as a long flap.
The humerus is sectioned at least 4 cm from the joint to allow for the prosthetic elbow mechanism. After the contour of the humeral end is smoothed with a rasp, the triceps flap is carried anteriorly and sutured to the fascia of the anterior muscular compartment.
Transhumeral amputations proximal to supracondylar area
Amputations that are proximal to the supracondylar area should maintain all possible length. In traumatic amputations, it should be considered whether free-flap coverage and skin-graft coverage are possible alternatives before the choice of additional bone resections to allow primary closure.
Skin and muscle flaps are fashioned as previously described. Neurovascular bundles are isolated and transected in order to retract into the proximal stump. The anterior and posterior fascias over the flexor and extensor muscle masses are sutured together to cover the end of the humerus. It may be necessary to trim some of the muscle fibers to decrease bulk and better contour the final stump. Alternatively, closure may be accomplished in two layers, with the subcutaneous tissue and skin used to contour the end of the stump.
Transhumeral amputations at or above the level of the pectoralis major insertion deserve special consideration. Bony resection through the level of the surgical neck functions as a shoulder disarticulation because independent motion of the humerus is no longer possible. However, preservation of the humeral head retains the normal contour of the shoulder, which is cosmetically desirable. Furthermore, the stability of a disarticulation prosthesis is enhanced if a portion of the humerus remains.
The technique of amputating through the surgical neck involves placing the patient in a position that allows access to the anterior and posterior shoulder. "Beach-chair" or "sloppy" lateral decubitus positions are commonly used. The incision begins at the coracoid and follows the inferior border of the anterior and posterior deltoid to its insertion laterally. Crossing the axilla with an additional incision connects the two limbs of the incision.
The cephalic vein is identified within the deltopectoral groove and divided proximally. The deltoid and the pectoralis major are freed from their insertions at the humerus. The plane between the coracobrachialis and the pectoralis minor is developed. The pectoralis minor is left attached to the coracoid, and the coracobrachialis is removed from its origin, revealing the neurovascular bundle underneath. The axillary artery, as well as the radial, median, ulnar, and musculocutaneous nerves, should be isolated and divided so that they retract deep to the pectoralis minor.
The lateral flap of the deltoid is developed from the humerus. The axillary nerve on the undersurface of the deltoid must remain intact during this dissection. If this nerve is injured, atrophy caused by denervation of the deltoid compromises stump cushion and prosthetic fit.
Near their insertions at the bicipital groove, the teres major and the latissimus dorsi should be divided. The long and short heads of the biceps, triceps, and coracobrachialis are divided approximately 2 cm distal to the level of intended bony section. After the humerus is cut and rounded, the long head of the triceps, the two heads of the biceps, and the coracobrachialis are sutured together as a myofascial flap over the end of the humerus.
Alternatively, both heads of the biceps may be divided and allowed to retract proximally into the stump. In either alternative, the pectoralis major is advanced laterally and secured to the end of the humerus. The deltoid flap covers the remaining bone and is sutured to the skin of the axilla. Some contouring of the deltoid flap may be necessary to ensure proper skin approximation.
Shoulder disarticulation
Disarticulations at the shoulder level severely hinder prosthetic function because virtually all shoulder motion is lost. In fact, the prosthesis is used primarily as a holding device when the patient is performing activities with both hands. As previously explained, sparing the humeral head is preferable whenever possible to obtain the best appearance and prosthetic fit.
Shoulder disarticulation is performed in a manner similar to that described for amputations at the level of the pectoralis major, with a few notable exceptions. After ligation and division of the axillary artery, the thoracoacromial artery can be identified just at the medial border of the pectoralis minor tendon, where it emerges from the second portion of the axillary artery. From this artery, the acromial branch may be observed lying on the pectoralis minor tendon and coursing toward the acromion. This vessel should be ligated and allowed to retract.
By placing the arm in extreme internal rotation, the short external rotator muscles and the posterior capsule are exposed and easily sectioned. Placing the arm in extreme external rotation facilitates division of the anterior capsule and the subscapularis. After excision of the humeral head, the cut ends of all muscles are reflected and secured into the glenoid cavity in an effort to fill the resulting hollow. Finally, partial excision of the acromion may be necessary to smooth the contour of the shoulder.
Forequarter amputations
A forequarter amputation (FQA), also referred to as a shoulder girdle or interscapulothoracic amputation, removes the entire upper extremity and shoulder girdle in the interval between the scapula and thoracic wall. This operation is reserved for malignant tumors that extend to the region of the shoulder joint or infiltrate the deltoid, pectoral, or subscapular muscles. [16] The functional prognosis is poor following this procedure, and the 5-year survival rate for patients was reported to be only 23%, presumably because of the grave circumstances that warrant such a radical procedure. [11]
Two techniques have been described. The classic anterior approach introduced by Berger involves ligating the major vessels as the preliminary step. [17] Littlewood described a posterior approach, which is regarded by most as somewhat less technically demanding. [18]
The anterior approach begins with the upper limb of the incision, which starts at the lateral border of the sternocleidomastoid, extends laterally along the anterior aspect of the clavicle and across the acromioclavicular joint and the superior aspect of the shoulder to the scapular spine, and then progresses inferiorly along the vertical border of the scapula to the scapular angle. The lower limb of the incision begins at the middle third of the clavicle, extends along the deltopectoral groove, and continues across the axilla to connect to the upper limb of the incision at the angle of the scapula.
Reflect the clavicular portion of the pectoralis major, and expose the entire clavicle. Retract the external jugular vein from the field, or section the vein if it remains in the way. With a saw, divide the clavicle at the lateral border of the sternocleidomastoid and remove the bone by disarticulating the acromioclavicular joint. The subclavian muscle is divided medially. Releasing the insertions of the pectoralis major from the humerus and the pectoralis minor from the coracoid process exposes the subclavian artery and vein for double ligation and division. The brachial plexus is gently pulled distally into the field and sectioned to allow retraction superiorly.
The latissimus dorsi and remaining soft tissues that bind the shoulder girdle anteriorly to the chest wall are divided, followed by the muscles that hold the scapula to the thorax. Begin by dividing the trapezius, and continue through the omohyoid, levator scapulae, rhomboid major and minor, and serratus anterior. The limb is then removed. For additional padding, the pectoralis major, the trapezius, and any other remaining muscular structures may be sutured over the lateral chest wall. Given the circumstances under which this procedure is required, atypical flaps and skin grafts are often used, which may complicate closure.
The more popular posterior approach has the advantage of easily mobilizing the limb before the more challenging anterior dissection to gain vascular control. The approach involves two incisions. The first, which is the posterior cervicoscapular incision, begins at the medial end of the clavicle, extends laterally for its entire length, proceeds over the acromion to the posterior axillary fold, and then continues along the axillary border of the scapula to the scapular angle, where it curves medially to end 5 cm from the midline of the back.
The trapezius and the latissimus dorsi are divided parallel with the scapula. The levator scapulae, the rhomboids, and the scapular attachments of the serratus anterior and omohyoid are divided. Careful cauterization of the branches from the transverse cervical and transverse scapular arteries is warranted. The subclavian muscle is divided medially, as is the clavicle lateral to the insertion of the sternocleidomastoid. The extremity is then allowed to fall anteriorly, thus exposing the subclavian vessels and brachial plexus for relatively easy division.
The second incision, which is the anterior pectoroaxillary incision, begins at the middle of the clavicle and then curves laterally to the deltopectoral groove and toward the axillary fold, where it joins the posterior axillary incision at the lower axillary border of the scapula. Finally, the pectoralis major and minor are divided, and the limb is removed.
Radical forequarter amputation
Roth et al described a radical FQA that includes the chest wall. [19] Indications for this procedure are extensive tumors that involve the shoulder girdle, chest wall, or axilla. Thoracic surgeons are usually involved with this type of procedure.
Tikhoff-Linberg procedure
In rare instances, such as when well-localized tumors of limited extent are present, resection of the shoulder girdle with preservation of the arm may be indicated. When it is feasible, this procedure is preferable to the more disfiguring FQA, because the Tikhoff-Linberg procedure preserves some distal extremity function.
The anterior and posterior portions of the technique are similar to those of the FQA described by Berger. However, the humerus is transected at the appropriate level and the proximal portion is removed. Once the shoulder girdle is excised, it may be possible to reattach some of the remaining arm musculature proximally, either to the rib cage or to the soft-tissue attachments about the hemithorax.
A variation of the Tikhoff-Linberg procedure is to perform a partial or complete scapulectomy, leaving the humerus intact. One study reviewed 12 patients undergoing complete scapulectomies for malignancies. [20] At 6 months, there were no deaths and no local or regional recurrences. The authors concluded that scapulectomy remains an excellent procedure for local tumor control with preservation of distal limb function, though follow-up care was short for some patients and residual function was not defined clearly.
Postoperative Care
A soft compressive dressing is applied to the stump. The elastic bandage is applied more tightly distally than proximally to prevent stump edema. Rigid dressings and casts, such as those often used on lower-extremity stumps, are unnecessary for the upper extremity. If a drain is placed, it is removed within 24-48 hours. Provided that no contraindications exist for anticoagulation, low-dose subcutaneous heparin (5000 U q12hr) may be administered for deep venous thrombosis (DVT) prophylaxis, especially in the case of high-risk patients. Immediate active range of motion (ROM) of the shoulder, if applicable, is implemented to prevent joint contractures.
Complications
Hematoma
Meticulous hemostasis and, if necessary, the use of a drain can minimize the occurrence of postoperative hematomas. If allowed to accumulate, hematomas may provide an attractive medium for bacteria and may inhibit proper wound healing. Aspiration of the hematoma under sterile conditions is recommended, followed by the use of a compressive dressing to reduce the recurrence rate. If hematoma accumulation persists, surgical exploration, instead of resorting to repeat aspirations, may be required to achieve adequate hemostasis.
Infection
Upper-extremity amputation stump infections are more likely to occur in patients who are immunocompromised or who have previous vascular diseases, as well as in patients with grossly contaminated or infected wounds. As with any postoperative infection, superficial infections may be treated with proper wound care, antibiotics, and close observation, but deep infections, whether accompanied by an abscess or not, may require further surgical débridement and possibly revision amputation to a more proximal level. It has been suggested that delaying formal amputation closure for at least 5 days after the procedure may reduce the rate of postoperative infection. [21]
Necrosis
As with infections, superficial areas of skin necrosis may be treated conservatively because healing usually continues under the eschar. However, larger areas of necrosis indicate insufficient vascularization and demand resection or possibly revision amputation to a more proximal level.
Neuroma
Regardless of the technique employed to divide peripheral nerves, a neuroma always forms. If the neuroma is compressed against a rigid surface (eg, a bone or a prosthetic wall) or if the neuroma experiences traction as it remains trapped in the healing scar, pain inevitably occurs.
Efforts to prevent the compression or entrapment of neuromas have previously been described. When a neuroma becomes symptomatic, it can usually be treated by altering the prosthetic socket so that pressure or traction on the lesion is avoided. When all nonoperative efforts have failed to relieve pain, the neuroma may be successfully excised, and the nerve can be divided at a more proximal level. In children, neuromas seldom warrant surgical intervention.
Phantom sensation
This poorly understood phenomenon is defined as the patient's awareness of the amputated portion of the limb. [22, 23, 24] The sensations may be disturbing but are rarely painful.
Many modalities have been used in an attempt to prevent or minimize the intensity of the sensations. Amitriptyline and gabapentin can be considered first-line agents in the pharmacologic treatment of phantom sensations. Other agents used less commonly are capsaicin, calcitonin, mexiletine, carbamazepine, propranolol, metoprolol, and clonazepam. Many of these drugs have only case-report usage and require further investigation.
Promising therapies for the upper extremity have included immediate or early prosthetic fitting. Substantial evidence also exists to support the use of perioperative epidural anesthesia and postoperative intraneural anesthesia that, though normally applied to transected nerves in amputated lower extremities, may be effective in the upper extremities. However, such data for the upper extremities are not yet available. Phantom sensations are uncommon in children.
Deep venous thrombosis
Patients who have undergone amputation may be at increased risk for DVT. Although persons with upper-extremity amputations are able to mobilize more easily after surgery than those with lower-extremity amputations (and consequently present less often with DVT), their underlying medical conditions often predispose them to this complication. This is because of multiple risk factors for DVT in this population, such as age, some degree of immobility, and the amputation itself, which involves the ligation of vessels.
Furthermore, 25% of patients undergoing vascular surgery have an identifiable hypercoagulable state. Unfortunately, most data pertain to individuals with lower-extremity amputations; therefore, it is difficult to make conclusions about the risks for persons with upper-extremity amputations.
Nevertheless, it is advisable to administer low-dose subcutaneous heparin to patients who have undergone amputations while they are still in the hospital, provided that they have no contraindications to anticoagulation. Low-molecular-weight heparins (LMWHs), such as enoxaparin and dalteparin, may increase the risk of bleeding and hematoma formation and may induce more anticoagulation than is necessary in the upper extremity. However, further research is required to assess the risks and benefits of anticoagulation therapy in this setting.
Terminal overgrowth
Although many amputation complications, such as neuroma or phantom pain, are less problematic in children, terminal overgrowth occurs to some degree in all children with amputations; as many as 12% of children with amputations require one or more stump revisions.
Above-elbow amputations are more problematic in this regard than any other amputation because the humerus is most commonly associated with this phenomenon. In above-elbow amputations, the humerus frequently overgrows distally and often with varus angulation. The cause of overgrowth is still controversial. Contracture of the soft-tissue envelope and disproportionate growth of bone from the proximal physis to the soft tissue have been implicated. However, a current hypothesis points to malfunctioning and acceleration of established mechanisms of normal fracture healing and local wound healing. [25]
Pediatric patients with disarticulations do not demonstrate terminal overgrowth, because the articular cartilage acts as a natural barrier to this activity. For this reason, as well as to preserve the distal physis and maintain normal stump growth, disarticulations are the treatment of choice in children whenever possible. Most attempts to prevent terminal overgrowth, including capping the bony ends with Silastic or with allograft and autograft tissues, have failed. The only treatment for symptomatic terminal overgrowth is revision amputation.
Bony spur
Bony spurs occasionally form at the end of the bones, especially in children. Unlike terminal overgrowth, bony spurs almost never require resection and are well tolerated after prosthetic socket modifications.
Contracture
Shoulder contractures are usually prevented with immediate postoperative active motion, when applicable. If contractures develop, more aggressive physical therapy may be required, including strengthening of the opposing musculature and the use of gentle passive motion.
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The various levels of an upper extremity amputation.