Annals of the Royal College of Surgeons of England (1991) vol. 73, 152-154
Above-knee
amputation
S J D Chadwick
MS FRCS Senior Registrar in General Surgery
St Mary's Hospital, London
J D Lewis
FRCS Consultant Vascular Surgeon
Northwick Park Hospital, Harrow, Middlesex The goal for all amputees is to achieve an independent and mobile existence. As most major lower limb ablations are for peripheral vascular disease, which particularly affects the elderly, the problems of management are likely to be compounded by associated widespread arterial disease, other medical conditions and social status. In addition, not only does the amputee have to adapt to the use of a prosthesis but also a significant alteration of body image and, in some instances, an emotion similar to the loss of a loved one. Thus, the patient has enough to contend with without the additional burden of a 'technical complication' of the amputation.
Preoperative management Except in the rare instance of an amputation performed at the site of trauma, amputations are either urgent or planned. This allows some time to counsel the patient upon reasonable expectations and to introduce members of the hospital staff (nursing, physiotherapy, occupational therapy and social workers) who will interact with the patient during hospital stay. The Disablement Service Centre (DSC) medical officer should be contacted, as he/she too may be able to visit the patient preoperatively. The general practitioner should also be informed of the proposed amputation. Specific medical attention should be directed towards ensuring the patient is as fit as possible for the amputation. The 'healthy' limb requires careful examination and, if necessary, vascular intervention considered. If time allows, physiotherapy to the arms, trunk and healthy limb should be started.
Correspondence to: Mr J D Lewis FRCS, Consultant Vascular Surgeon, Northwick Park Hospital, Watford Road, Harrow, Middlesex HAI 3UJ
Operation Preoperatively, the condition of the patient should be discussed with the anaesthetist so that a decision regarding the type of anaesthesia can be made. If a regional anaesthetic is to be used we have found it useful to loan the patient a personalised stereo during the procedure. In the anaesthetic room the surgeon should check the identity of the patient and that the site of amputation is correctly marked. Intravenous antibiotics (penicillin and a broad-spectrum agent) are started. If the patient has a preoperative haemoglobin concentration of less than 11 g/dl, two units of blood should have been crossmatched and available in theatre. After induction of anaesthesia the patient is placed supine on the operating table. Based on a clinical decision, a urinary catheter may be inserted per urethra. If the lower limb is ischaemic with ulceration it should be placed in a plastic bag, the open end of which is wrapped flush with the skin below the knee. The surgeon, gowned and gloved, prepares the skin of the lower anterior abdominal wall and anterior thigh and knee. An assistant lifts the leg and gently abducts the hip so that the posterior skin of the thigh, lower buttock and perineum can be prepared. With the leg still elevated towels are placed across the operating table. The lower leg is wrapped in a green towel and covered with a stockinet up to the knee joint. The limb is placed on the operating table and towels positioned to cover the lower abdomen at the level of the anterior superior iliac spine. A towel is placed to cover the external genitalia and to exclude the perineum. We do not use a plastic adhesive skin drape. As most amputations are for ischaemia a tourniquet is not required. Once the preparations are complete, the knee and hip are flexed to 90° and the limb supported by the assistant. The apex of the skin flap is marked on the lateral side of the thigh first. As a rule of thumb, this is approximately a hand's span (20-25 cm) from the greater trochanter, or a palm's breadth (10 cm) from the upper border of the patella. By placing the index finger of the left hand on
Above-knee amputation
Greater Trochanter
20-25cm
Site of division of Minimal length of
10cm
distal femur
to amputate > 10cm
Upper border of patella
Figure 1. Anatomical site of amputation.
this lateral skin mark perpendicular to the skin and wrapping the thumb around the upper thigh, the apex of the medial incision can be marked. From each of these two points the flaps are drawn in an inverted U shape, the anterior skin flap approaching the upper border of the patella. The usual method of this operation describes equal length anterior and posterior flaps. However, when possible, we prefer to use a shorter length posterior flap, the base of which is some 3-5 cm shorter than the anterior flap, ensuring a true posterior scar once healing is complete. The anterior flap is cut first with a bold positive stroke using a large scalpel blade. The incision traverses skin, subcutaneous fat and muscle or quadriceps tendon to the bone at the base of the flap. A continuous sweeping motion of the knife is far preferable, resulting in much less trauma and fraying of the skin margin. The posterior flap is incised with a similar technique; in this instance, however, the incision takes skin and subcutaneous tissues. The anterior incision is deepened to the bone
Figure 2. Lateral aspect. The anterior flap is 3-5 cm longer than the posterior flap. A suture has been passed through the anterior muscle mass, two holes drilled in the femur and the posterior muscle mass.
153
from the base to the lateral apex. The incision on the medial side of the upper flap is also deepened, but caution must be exercised until the subsartorial canal is entered when the major vessels are identified and individually ligated with non-absorbable sutures at the apex of the incision. The posterior muscle groups may then be divided in the line of the skin incision, again using firm pressure on the scalpel to avoid fraying of the muscles. The operator concentrates on division of muscles and the assistant upon control of haemorrhage. When muscle division is complete, the flaps of skin and muscle are folded back and the site of division of the femur is checked by measurement from the greater trochanter and distal end of the femur. The length of distal femur amputated should be >10 cm. By retaining a longer stump, the prosthetist will be unable to fit a socket and joint that will be complementary to the other leg. Thus, when the patient sits down the prosthetic knee will be prominent. The shortest length of the stump is not so critical because adaptions can be made by the prosthetist. However, short stumps are mechanically disadvantaged. At the site of division of the femoral shaft, the periosteum is incised and the periosteum elevated for some 23 cm above the line of incision. Posteriorly, muscle attachments to the linea aspera are separated. With the flaps protected by large packs or a metallic muscle shield, and the hip and knee flexed at 900 the bone is divided. The amputated limb is then wrapped in the stockinet and discarded, unless some or all of the limb is required for pathological examination. If the latter is the case, prior discussion with the histopathologist is required to determine the method of preservation to be used. Attention is then returned to the stump which the assistant elevates and a large bowel or kidney dish covered in a clean towel is placed underneath. The end of the bone is smoothed with a hand-held file or rasp. Haemostasis is achieved mainly by careful ligature with absorbable ligatures. Diathermy may be used sparingly and only on smaller vessels. The sciatic nerve is identified between the long head of biceps femoris laterally and semimembranosus medially and it is pulled down below the level of the muscles by forceps traction. By applying mosquito forceps to the perineurium on each side, the vasa nervorum can be identified and diathermied. The sciatic nerve is then divided by knife and allowed to retract into the muscle bulk proximal to the end of the stump. Complete diathermy and phenolisation of the nerve end have been described as an attempt to reduce the incidence of phantom limb sensation and neuroma formation, but to the authors' knowledge neither has been shown in controlled studies to be superior to the method described above. The size and shape of the flaps in relation to the cut end of the bone are then checked such that the muscle and deep fascia will approximate without tension. Any excess is carefully removed using a scalpel, always erring on the side of laxity of the stump flaps. The muscles are now lavaged with hydrogen peroxide to wash away any bone fragments and other debris. Haemostasis is finally
154
S
D Chadwick andj D Lewis
checked. Bone wax may be applied to the bone stump if there is oozing. Two suction drains are inserted beneath the main muscle mass, exiting through the skin 5-10 cm proximal to the apices of the incision; they are not sutured to the skin to allow removal in the early postoperative period without disturbance of the stump dressing. The original myoplastic technique described the apposition of flexors and extensors, adductors and abductors across the bone end. This can produce an awkward end result in which the muscle slides over the bone and may result in ulceration of the bone through the skin; furthermore, it may be difficult to obtain in the presence of marked wasting, a frequent accompaniment of atherosclerosis. Of more value would seem to be the fixation of muscle groups to their opposite group and to the femoral stump. A series of holes (2-6) are drilled 1 cm proximal to the bone end. Through these holes and the muscle groups an absorbable suture is passed but left untied. When all the muscle has been apposed in this way the sutures are tied, thus fixing muscle to bone over the two drains. Next, the deep fascia is sutured using interrupted absorbable sutures starting in the midline. The next deep fascial sutures are placed at the midpoint between the apices of the incision and the anterior suture. Segmental closing of the deep fascia is continued in this manner. This allows a gradual evening out of any discrepancies between the anterior and posterior flaps. This layer is of considerable importance in terms of maintaining wound integrity and its value has been greatly enhanced by the use of semisynthetic suture materials which retain their strength for longer than catgut. The skin is closed in the same segmented fashion using a fine (4/0) nonabsorbable synthetic suture and employing a simple stitch technique with good approximation of the edges, but relatively loose knot tying. On no account should mattress sutures be used since this will predispose the skin to ischaemia and breakdown. After completion of the skin suture, the wound is covered with an absorbent dressing and cotton wool. The stump is bandaged with crepe, firmly but not tightly. The drains are brought out at the upper end of the bandage. Adhesive bandage is then applied from the anterior abdominal wall and buttock over the crepe to provide support and prevent slippage. In the presence of extensive ischaemia, such as in the late presentation of acute ischaemia where obvious skin mottling is present, all non-viable skin must be excluded from the lines of incision and all non-viable muscle excised. It is often more satisfactory to attempt to produce flaps during initial surgery rather than to undertake a guillotine amputation. In this situation partial temporary closure and early reinspection of the stump is advocated. In rare situations it is necessary to undertake disarticulation of the hip, leaving virtually no surrounding muscle in the flaps but merely trying to obtain a reasonable amount of posterior thigh and buttock skin to reduce the size of skin defect to a minimum.
Postoperative management In the early postoperative period, pain control may require strong analgesia. This should not be continued inadvertently for too long as it runs the risk of dependence and constipation. The drains may be removed when the drainage is less than 15 ml/24 h, usually within the first 2 or 3 days of operation. Removal of the drains should not require dressing disturbance, if the drains have not been sutured to the skin. Antibiotics are continued for 5 days, at this time the wound is inspected. If there is any suggestion of deep anaerobic infection, such as a characteristic smell, a high fever, toxic confusion or a serosanguinous stain on the dressing, the wound must be inspected earlier. Stump physiotherapy may be started as soon as the patient is comfortable. If a flexion contracture exists, no attempt should be made to forcibly resist as this will potentiate the contracture. Stitches may be removed between the 10th and 14th day if the skin wound appears to be healing soundly. Unnecessary delay in removal of stitches may be a focus for infection. In elderly ladies with thin skin, the wound is particularly vulnerable to breakdown after only minor injury, so great care must be exercised to prevent local trauma, particularly during transfer from bed to chair. If the wound does break down, the stump must be assessed to identify the cause, if it is ischaemia then amputation at a higher level may be required. Until the wound is soundly healed no attempt should be made to apply a compression bandage to mould the stump. Before the stitches have been removed, mobilisation on parallel bars and a pneumatic post-amputation mobility (PPAM) aid under the supervision of a trained physiotherapist may be started. However, if it is apparent that the patient will never manage on a prosthesis, a cosmetic limb should be offered and wheelchair training given. The patient should be offered a useful booklet 'Your Next Step Forward' issued by the Department of Health and Social Security. This provides a useful introduction to the DSC and the services offered. It also gives a list and addresses of useful organisations the patient may wish to contact. Finally, before discharge a home visit should be made with the occupational therapist and social worker. Structural alterations to the home or even new accommodation may be required. Inpatient and outpatient physiotherapy will be required until the patient is confident on the prosthesis and regular outpatient review is mandatory.
We wish to thank Dr A Hewlett FFARCS, Consultant Anaesthetist, for his helpful comments during the preparation of this article.
Above-knee
amputation
S J D Chadwick
MS FRCS Senior Registrar in General Surgery
St Mary's Hospital, London
J D Lewis
FRCS Consultant Vascular Surgeon
Northwick Park Hospital, Harrow, Middlesex The goal for all amputees is to achieve an independent and mobile existence. As most major lower limb ablations are for peripheral vascular disease, which particularly affects the elderly, the problems of management are likely to be compounded by associated widespread arterial disease, other medical conditions and social status. In addition, not only does the amputee have to adapt to the use of a prosthesis but also a significant alteration of body image and, in some instances, an emotion similar to the loss of a loved one. Thus, the patient has enough to contend with without the additional burden of a 'technical complication' of the amputation.
Preoperative management Except in the rare instance of an amputation performed at the site of trauma, amputations are either urgent or planned. This allows some time to counsel the patient upon reasonable expectations and to introduce members of the hospital staff (nursing, physiotherapy, occupational therapy and social workers) who will interact with the patient during hospital stay. The Disablement Service Centre (DSC) medical officer should be contacted, as he/she too may be able to visit the patient preoperatively. The general practitioner should also be informed of the proposed amputation. Specific medical attention should be directed towards ensuring the patient is as fit as possible for the amputation. The 'healthy' limb requires careful examination and, if necessary, vascular intervention considered. If time allows, physiotherapy to the arms, trunk and healthy limb should be started.
Correspondence to: Mr J D Lewis FRCS, Consultant Vascular Surgeon, Northwick Park Hospital, Watford Road, Harrow, Middlesex HAI 3UJ
Operation Preoperatively, the condition of the patient should be discussed with the anaesthetist so that a decision regarding the type of anaesthesia can be made. If a regional anaesthetic is to be used we have found it useful to loan the patient a personalised stereo during the procedure. In the anaesthetic room the surgeon should check the identity of the patient and that the site of amputation is correctly marked. Intravenous antibiotics (penicillin and a broad-spectrum agent) are started. If the patient has a preoperative haemoglobin concentration of less than 11 g/dl, two units of blood should have been crossmatched and available in theatre. After induction of anaesthesia the patient is placed supine on the operating table. Based on a clinical decision, a urinary catheter may be inserted per urethra. If the lower limb is ischaemic with ulceration it should be placed in a plastic bag, the open end of which is wrapped flush with the skin below the knee. The surgeon, gowned and gloved, prepares the skin of the lower anterior abdominal wall and anterior thigh and knee. An assistant lifts the leg and gently abducts the hip so that the posterior skin of the thigh, lower buttock and perineum can be prepared. With the leg still elevated towels are placed across the operating table. The lower leg is wrapped in a green towel and covered with a stockinet up to the knee joint. The limb is placed on the operating table and towels positioned to cover the lower abdomen at the level of the anterior superior iliac spine. A towel is placed to cover the external genitalia and to exclude the perineum. We do not use a plastic adhesive skin drape. As most amputations are for ischaemia a tourniquet is not required. Once the preparations are complete, the knee and hip are flexed to 90° and the limb supported by the assistant. The apex of the skin flap is marked on the lateral side of the thigh first. As a rule of thumb, this is approximately a hand's span (20-25 cm) from the greater trochanter, or a palm's breadth (10 cm) from the upper border of the patella. By placing the index finger of the left hand on
Above-knee amputation
Greater Trochanter
20-25cm
Site of division of Minimal length of
10cm
distal femur
to amputate > 10cm
Upper border of patella
Figure 1. Anatomical site of amputation.
this lateral skin mark perpendicular to the skin and wrapping the thumb around the upper thigh, the apex of the medial incision can be marked. From each of these two points the flaps are drawn in an inverted U shape, the anterior skin flap approaching the upper border of the patella. The usual method of this operation describes equal length anterior and posterior flaps. However, when possible, we prefer to use a shorter length posterior flap, the base of which is some 3-5 cm shorter than the anterior flap, ensuring a true posterior scar once healing is complete. The anterior flap is cut first with a bold positive stroke using a large scalpel blade. The incision traverses skin, subcutaneous fat and muscle or quadriceps tendon to the bone at the base of the flap. A continuous sweeping motion of the knife is far preferable, resulting in much less trauma and fraying of the skin margin. The posterior flap is incised with a similar technique; in this instance, however, the incision takes skin and subcutaneous tissues. The anterior incision is deepened to the bone
Figure 2. Lateral aspect. The anterior flap is 3-5 cm longer than the posterior flap. A suture has been passed through the anterior muscle mass, two holes drilled in the femur and the posterior muscle mass.
153
from the base to the lateral apex. The incision on the medial side of the upper flap is also deepened, but caution must be exercised until the subsartorial canal is entered when the major vessels are identified and individually ligated with non-absorbable sutures at the apex of the incision. The posterior muscle groups may then be divided in the line of the skin incision, again using firm pressure on the scalpel to avoid fraying of the muscles. The operator concentrates on division of muscles and the assistant upon control of haemorrhage. When muscle division is complete, the flaps of skin and muscle are folded back and the site of division of the femur is checked by measurement from the greater trochanter and distal end of the femur. The length of distal femur amputated should be >10 cm. By retaining a longer stump, the prosthetist will be unable to fit a socket and joint that will be complementary to the other leg. Thus, when the patient sits down the prosthetic knee will be prominent. The shortest length of the stump is not so critical because adaptions can be made by the prosthetist. However, short stumps are mechanically disadvantaged. At the site of division of the femoral shaft, the periosteum is incised and the periosteum elevated for some 23 cm above the line of incision. Posteriorly, muscle attachments to the linea aspera are separated. With the flaps protected by large packs or a metallic muscle shield, and the hip and knee flexed at 900 the bone is divided. The amputated limb is then wrapped in the stockinet and discarded, unless some or all of the limb is required for pathological examination. If the latter is the case, prior discussion with the histopathologist is required to determine the method of preservation to be used. Attention is then returned to the stump which the assistant elevates and a large bowel or kidney dish covered in a clean towel is placed underneath. The end of the bone is smoothed with a hand-held file or rasp. Haemostasis is achieved mainly by careful ligature with absorbable ligatures. Diathermy may be used sparingly and only on smaller vessels. The sciatic nerve is identified between the long head of biceps femoris laterally and semimembranosus medially and it is pulled down below the level of the muscles by forceps traction. By applying mosquito forceps to the perineurium on each side, the vasa nervorum can be identified and diathermied. The sciatic nerve is then divided by knife and allowed to retract into the muscle bulk proximal to the end of the stump. Complete diathermy and phenolisation of the nerve end have been described as an attempt to reduce the incidence of phantom limb sensation and neuroma formation, but to the authors' knowledge neither has been shown in controlled studies to be superior to the method described above. The size and shape of the flaps in relation to the cut end of the bone are then checked such that the muscle and deep fascia will approximate without tension. Any excess is carefully removed using a scalpel, always erring on the side of laxity of the stump flaps. The muscles are now lavaged with hydrogen peroxide to wash away any bone fragments and other debris. Haemostasis is finally
154
S
D Chadwick andj D Lewis
checked. Bone wax may be applied to the bone stump if there is oozing. Two suction drains are inserted beneath the main muscle mass, exiting through the skin 5-10 cm proximal to the apices of the incision; they are not sutured to the skin to allow removal in the early postoperative period without disturbance of the stump dressing. The original myoplastic technique described the apposition of flexors and extensors, adductors and abductors across the bone end. This can produce an awkward end result in which the muscle slides over the bone and may result in ulceration of the bone through the skin; furthermore, it may be difficult to obtain in the presence of marked wasting, a frequent accompaniment of atherosclerosis. Of more value would seem to be the fixation of muscle groups to their opposite group and to the femoral stump. A series of holes (2-6) are drilled 1 cm proximal to the bone end. Through these holes and the muscle groups an absorbable suture is passed but left untied. When all the muscle has been apposed in this way the sutures are tied, thus fixing muscle to bone over the two drains. Next, the deep fascia is sutured using interrupted absorbable sutures starting in the midline. The next deep fascial sutures are placed at the midpoint between the apices of the incision and the anterior suture. Segmental closing of the deep fascia is continued in this manner. This allows a gradual evening out of any discrepancies between the anterior and posterior flaps. This layer is of considerable importance in terms of maintaining wound integrity and its value has been greatly enhanced by the use of semisynthetic suture materials which retain their strength for longer than catgut. The skin is closed in the same segmented fashion using a fine (4/0) nonabsorbable synthetic suture and employing a simple stitch technique with good approximation of the edges, but relatively loose knot tying. On no account should mattress sutures be used since this will predispose the skin to ischaemia and breakdown. After completion of the skin suture, the wound is covered with an absorbent dressing and cotton wool. The stump is bandaged with crepe, firmly but not tightly. The drains are brought out at the upper end of the bandage. Adhesive bandage is then applied from the anterior abdominal wall and buttock over the crepe to provide support and prevent slippage. In the presence of extensive ischaemia, such as in the late presentation of acute ischaemia where obvious skin mottling is present, all non-viable skin must be excluded from the lines of incision and all non-viable muscle excised. It is often more satisfactory to attempt to produce flaps during initial surgery rather than to undertake a guillotine amputation. In this situation partial temporary closure and early reinspection of the stump is advocated. In rare situations it is necessary to undertake disarticulation of the hip, leaving virtually no surrounding muscle in the flaps but merely trying to obtain a reasonable amount of posterior thigh and buttock skin to reduce the size of skin defect to a minimum.
Postoperative management In the early postoperative period, pain control may require strong analgesia. This should not be continued inadvertently for too long as it runs the risk of dependence and constipation. The drains may be removed when the drainage is less than 15 ml/24 h, usually within the first 2 or 3 days of operation. Removal of the drains should not require dressing disturbance, if the drains have not been sutured to the skin. Antibiotics are continued for 5 days, at this time the wound is inspected. If there is any suggestion of deep anaerobic infection, such as a characteristic smell, a high fever, toxic confusion or a serosanguinous stain on the dressing, the wound must be inspected earlier. Stump physiotherapy may be started as soon as the patient is comfortable. If a flexion contracture exists, no attempt should be made to forcibly resist as this will potentiate the contracture. Stitches may be removed between the 10th and 14th day if the skin wound appears to be healing soundly. Unnecessary delay in removal of stitches may be a focus for infection. In elderly ladies with thin skin, the wound is particularly vulnerable to breakdown after only minor injury, so great care must be exercised to prevent local trauma, particularly during transfer from bed to chair. If the wound does break down, the stump must be assessed to identify the cause, if it is ischaemia then amputation at a higher level may be required. Until the wound is soundly healed no attempt should be made to apply a compression bandage to mould the stump. Before the stitches have been removed, mobilisation on parallel bars and a pneumatic post-amputation mobility (PPAM) aid under the supervision of a trained physiotherapist may be started. However, if it is apparent that the patient will never manage on a prosthesis, a cosmetic limb should be offered and wheelchair training given. The patient should be offered a useful booklet 'Your Next Step Forward' issued by the Department of Health and Social Security. This provides a useful introduction to the DSC and the services offered. It also gives a list and addresses of useful organisations the patient may wish to contact. Finally, before discharge a home visit should be made with the occupational therapist and social worker. Structural alterations to the home or even new accommodation may be required. Inpatient and outpatient physiotherapy will be required until the patient is confident on the prosthesis and regular outpatient review is mandatory.
We wish to thank Dr A Hewlett FFARCS, Consultant Anaesthetist, for his helpful comments during the preparation of this article.
