Amputation (amputation) is the removal of a portion of a limb based on disease or trauma. The development of prosthetic technology has contributed to the change of the concept of amputation and the change of amputation surgery.
(A) The change of the concept of amputation
1. Amputation is not only a destructive surgery, but also a reconstructive and restorative surgery.
2, amputation is not the end of treatment, but the beginning of amputation rehabilitation.
3, amputation is the preparation for prosthesis installation, is the first step of the disabled back to society.
4.The amputation plane is mainly determined by the need of surgery, and the length of the limb is preserved as much as possible through intraoperative judgment.
5.The shape of the stump should be cylindrical rather than the traditional conical shape.
6.The rehabilitation work should be early intervention.
(II) Modern amputation techniques
Traditional prosthetic assembly, the length of the residual limb has high requirements; modern prosthetic assembly, no special requirements for the amputation plane, any reasonable composition, no pressure pain and good healing of the stump can be assembled prosthesis.
1, amputation plane upper limb to finger amputation for the most, forearm amputation, upper arm amputation, wrist joint severance, shoulder joint severance and elbow joint severance in decreasing order. The lower limbs are most often amputated by toe amputation, followed by lower leg amputation, thigh amputation, knee amputation, and knee amputation.
(1) Shoulder amputation: Preserve the humeral head as much as possible.
(2) Upper arm amputation: also known as transhumeralamputation (TH) or above-elbow amputation (AE). The reason for retaining the length as much as possible is that the function of the upper arm prosthesis depends on the lever arm length, muscle strength and shoulder joint range of motion of the residual limb, and the long residual limb facilitates the suspension and control of the prosthesis.
(3) Elbow disarticulation amputation: If the distal humerus can be preserved, elbow disarticulation is the ideal amputation site. Due to the design and application of the lateral hinge of the elbow joint, the appearance and function of the elbow disarticulation prosthesis are taken into account; the internal and external condyles of the humerus are conducive to the suspension and control of the prosthesis, and the rotation of the humerus can be directly transmitted to the prosthesis, so the distal humerus should not be decoratively corrected.
(4) Forearm amputation: also known as transradial amputation (transtadiaamputation, TR) or below-elbow amputation (BELOW-elbowamputation, BE). Forearm amputation should preserve as much length as possible, even if it is a very short stump. Amputation through the proximal forearm, even if a very short forearm stump is retained, such as only 4-5 cm long, is preferable to elbow disarticulation or upper arm amputation. The longer the residual limb, the greater the leverage function and the more rotational function is preserved. When the length of the residual limb is retained 80%, the angle of rotation of the residual limb is 100o; the length of the residual limb is retained 55%, the angle of rotation of the residual limb is only 60o; the length of the residual limb is retained 35%, the angle of rotation of the residual limb is 0o. The distal end of the forearm is oval, which is conducive to the play of the rotation function of the prosthesis. The more residual limb muscles are preserved, the easier it is to obtain EMG signals, which is more conducive to the installation of myoelectric prosthesis.
(5) Wrist disarticulation amputation: The function of the prosthesis with wrist disarticulation is superior to forearm amputation because it preserves the lower ulnar radial joint of the distal forearm, thus allowing complete preservation of forearm rotation function. Although only 50% of the prerotation and postrotation movements are transmitted to the prosthesis, these movements are very important to the patient and it allows the maximum function of the residual limb.
(6) Partial hand amputation: including carpometacarpal joint disarticulation, metacarpal amputation and phalangeal amputation. The flexion and extension movements of the radial carpal joint can be applied by prosthesis and should be preserved; carpometacarpal joint dissection is an optional amputation site; metacarpal amputation and phalangeal amputation, especially thumb amputation, should try to preserve their length; multi-finger amputation should try to preserve the pinch and grip function of the hand.
(7) Hemipelvic amputation: try to retain the iliac crest and sciatic tuberosity to increase the suspension function and weight-bearing area of the prosthesis.
(8) Hip disarticulation amputation: try to preserve the femoral head and neck and amputate below the lesser trochanter to increase the weight-bearing area and improve the stability of the prosthesis and the ability of the residual limb to control the prosthesis.
(9) Thigh amputation: also known as transfemoralamputation (TF) or above-kneeamputation (AK). The length is preserved as much as possible from 3-5 cm below the sciatic tuberosity for very short thigh stump, and the silicone rubber liner sleeve with locking device can solve the prosthetic suspension, which is better than hip disarticulation amputation.
(10) knee disarticulation amputation: knee disarticulation preserves the intact femur, with a longer lever arm and larger weight-bearing area. The knee amputation prosthesis is suspended by the femoral condyles, and the height of the upper edge of the prosthesis receiving cavity is below the sciatic tuberosity, and the range of motion of the hip joint is basically unrestricted, so the effect of the knee amputation prosthesis is better than that of the thigh prosthesis. Since the knee disarticulation prosthesis is completely dependent on the weight bearing of the stump, the disarticulated joint surface should avoid scarring, while the patella is not preserved.
(11) Calf amputation: also known as transtibial amputation (TT) or below-knee amputation (BK). For short calf stump, as long as the attachment of patellar ligament is preserved, the function of knee joint can be obtained, and its prosthetic effect is obviously better than that of knee disarticulation; because of less soft tissue and poor blood flow in the distal calf, it is appropriate to choose mid-calf amputation.
(12) Syme amputation: Syme amputation is a distal tibiofibular condylar amputation, in which the basal articular surface of the inner and outer condyles is excised and rounded, and then the metatarsal heel flap is covered on the stump, and the flap is double horseshoe-shaped, and because the stump is covered by intact and good heel skin, it is stable, wear-resistant and not easy to break, so that the stump has good weight-bearing capacity.
(13) Partial foot amputation: including transmetatarsal amputation, transmetatarsalamputation, Lisfranc’samputation, Chopart’samputation The principle of partial foot amputation is to try to get the most out of the foot. The principle of partial foot amputation is to preserve the length of the foot as much as possible, that is, to preserve the length of the forefoot lever arm so that it can obtain sufficient posterior thrust at the end of the stance phase of the gait cycle. When the length of the forefoot lever arm is too short, it will cause great obstacles to fast walking, running and jumping.
2, skin treatment regardless of the level of amputation, the stump should have good skin coverage, and good stump skin should have appropriate mobility, stretch and normal sensation. The scar produced by wound healing may cause residual limb pain and skin damage in the piston movement of the prosthesis receiving cavity. Traumatic amputation should be handled according to skin survival and not shorten the limb by pursuing the requirements of skin incision during conventional amputation surgery; tumor amputation often uses atypical skin incisions and flaps.
(1) Upper limb amputation: the anterior and posterior flaps of the residual limb are equal in length. In the case of long forearm stump and wrist dissection, the skin flap on the flexor side is longer than that on the extensor side, with the aim of moving the scar to the extensor side.
(2) Lower limb amputation.
(① lower leg amputation, the anterior long and posterior short fish-mouth shaped flap is no longer commonly used, more often the posterior flap which needs to be lengthened is used, its flap with gastrocnemius muscle is actually a myocutaneous flap with medial and lateral heads of gastrocnemius muscle, its flap is richer in blood flow and provides a better soft tissue pad to the stump end.
② For thigh amputation, the flap design should be anteriorly long and posteriorly short, and the flap incision should intersect laterally beyond the plane of truncation. After cutting, the subfascial separation is made and the flap is turned upward, or a 25px thick rectus femoris flap is separated and cut at the same length as the anterior flap and turned upward along with the flap.
3, muscle treatment in the past amputation is to cut the muscle in the plane of osteotomy, let it retract, the muscle lost the attachment point and produce disuse atrophy, the formation of cone-shaped stump, suitable for the assembly of traditional prosthesis. Disadvantages: the stump is prone to edema, muscle atrophy, impaired venous return and nutritional disorders, which can easily cause serious complications such as residual limb pain. Nowadays, muscle fixation or/and muscle plication is widely used with the aim of improving muscle function and blood circulation in the stump and preventing phantom limb pain.
(1) Muscle fixation: myodesis is a procedure in which the muscle is cut at least 75px distal to the osteotomy to form a muscle flap, and the muscle flap is sutured to the adjacent side of the bone through a hole in the bone while maintaining the original tension of the muscle. Muscle fixation is prohibited in limbs with peripheral vascular disease or other causes of ischemia.
(2) Myoplastic surgery: myoplastic surgery (myoplastic) is to suture the corresponding muscle flaps to each other, the osteotomy end is completely covered and buried, keeping the muscle in its normal physiological functional state, forming a cylindrical residual limb, which can meet the assembly requirements of full contact and full weight-bearing prosthetic cavity.
4.The purpose of nerve treatment is to prevent neuroma. Methods.
(1) direct ligation with silk wire: first ligated with silk wire, and then cut the nerve.
(2) Ligation of the nerve epineurium: the nerve epineurium is cut longitudinally, the nerve bundle is stripped, the nerve bundle is cut, and the nerve epineurium is ligated and occluded so that the nerve fibers are buried in the occluded nerve epineurium tube to prevent the severed nerve stump from growing outward and forming neuroma.
5, bone processing general bone and periosteum cut at the same level, prohibit too much periosteum stripping to avoid bone end ring necrosis.
(1) Thigh amputation: flat and rounded edges of the femur severed end, do not leave broken periosteum.
(2) lower leg amputation: flat and rounded tibiofibular end, the tip of the tibial end should be cut into a small wedge-shaped surface with flat and rounded edges. The tibia and fibula can be of equal length, or the fibula is slightly shorter. The tibiofibular fusion can increase the weight-bearing function of the end of the residual limb and is suitable for adults with long residual limbs, but this operation is contraindicated in children with lower leg amputation.
6, vascular treatment even small vessels should be completely hemostatic.
Knowledge Links
The special characteristics of children’s amputation
Amputation plane: Children are more conservative than adults, and the length of the residual limb should be preserved as much as possible, especially the preservation of joint dissection and adjacent epiphysis area is preferable to amputation at the level above this area, and the preservation of joint and distal epiphysis of the joint is preferable to joint dissection. For example, a five-year-old child with a mid-thigh amputation becomes a short thigh stump by age fourteen because the distal femoral epiphysis is removed; a five-year-old child with a short calf amputation may form a calf stump of ideal length by age fourteen because of the growth of the proximal calf epiphysis.
Muscle management: muscle plication is used. Muscle fixation has damage to the distal end of the bone, and it is easy to cause overgrowth of the bone end, resulting in a nail-tip-like bone end, which may penetrate the skin and cause infection, so muscle fixation is prohibited for children’s amputation.
Bone treatment: the bone end is covered with periosteal bone cortical flap to limit the excessive growth of the bone end. The reason is that the fibula grows faster than the tibia, which may cause tibial entropion deformity or dislocation of the fibular head.
(D) treatment of residual limb after amputation
1, maintain a reasonable limb body position
After amputation, due to the imbalance of the muscle strength of the stump, it is easy to lead to joint contracture deformity. After the occurrence of joint contracture, the installation and use of prosthesis will be adversely affected.
The easiest way to prevent joint contracture is to place the residual limb in a functional position. For example, after the lower leg amputation, the knee joint should be completely straight, especially in sitting position; after the thigh amputation, the hip joint should be kept in a straight position and not abducted, and if conditions allow, prone position rest can be taken as far as possible.
2.Promote residual limb crumpling and shaping
In order to reduce swelling and promote residual limb crinkling, the residual limb can be wrapped with pressure, such as elastic bandage wrapping, wearing elastic socks, plaster hard bandage wrapping, etc., of which the more common method is elastic bandage wrapping.
(E) Treatment of residual limb after amputation
1, maintain a reasonable limb position after amputation, due to the imbalance of the muscle strength of the stump, easily lead to joint contracture deformity. After the occurrence of joint contracture, the installation and use of prosthesis will be adversely affected.
The easiest way to prevent joint contracture is to place the residual limb in a functional position. For example, after the lower leg amputation, the knee joint should be completely straight, especially in sitting position; after the thigh amputation, the hip joint should be kept in a straight position and not abducted, and if conditions allow, prone position rest can be taken as far as possible.
2.Promote the residual limb crinkle stereotypes in order to reduce swelling and promote the residual limb crinkle stereotypes, the residual limb can be wrapped with pressure, such as elastic bandage wrap, wearing elastic socks, plaster hard bandage wrap, etc., of which the more commonly used method is elastic bandage wrap.
(1) Bandage bandage of thigh stump.
(1) Starting from the groin in front, completely around the end of the stump to the gluteus maximus sulcus posteriorly, at least twice round trip.
(ii) After folding back posteriorly, wrap several times from the inside out to prevent downward slippage.
③ Wrap from the tip of the stump end to the top in a figure-of-eight pattern, loosening near and tightening far, the tighter it gets to the tip.
(iv) For good fixation, wrap around the top of the contralateral hip and cross over the outer side of the stump.
⑤ a bandage from the pelvis diagonally down, at least twice, covering at least the perineum to prevent protruding muscles in the exposed portion.
(6) Ending with a final wrap around the waist.
(2) Bandage wrapping of the lower leg stump.
(i) Starting from below the patella in front and posteriorly to the N fossa, at least twice round trip.
(ii) Fold back the bandage from the posterior and then wrap it around several times from the inside out to prevent the bandage from slipping off.
③ wrapping the tip of the stump in a figure of eight pattern.
(iv) Continue wrapping in the same manner as above, ending with a wrap around the superior portion of the femoral condyle.
⑤ the patella should be exposed in order not to interfere with joint movement
⑥The tighter it is against the tip, the tighter it ends above the knee.
(3) Bandage wrapping of the upper arm stump: refer to the wrapping of the thigh stump. To prevent the bandage from slipping, the bandage should be wrapped around the contralateral axilla.
(4) Bandage wrapping of forearm stump: refer to the wrapping of calf stump. In order to avoid the influence on the elbow joint activity, the posterior aspect of the elbow joint should be exposed when wrapping.