Above-the-knee amputation after a total knee replacement: prevalence,etiology, and functional outcome

BACKGROUND: Despite modern surgical techniques, salvage of a failed total knee replacement remains a challenge. In certain situations, when other treatment options have been exhausted, patients with a failed total knee replacement may become candidates for above-the-knee amputation. The objective of this study was to assess the prevalence, etiology, and functional outcome of above-the-knee amputation performed proximal to an ipsilateral total knee replacement. METHODS: From 1970 to 2000, 18,443 primary total knee replacements were performed at our institution; sixty-seven (0.36%) were eventually followed by above-the-knee amputation. Forty-two of the amputations were performed for a cause unrelated to the total knee replacement, most commonly peripheral vascular disease (twenty-four knees). The remaining twenty-five above-the-knee amputations were performed for causes related to the total knee replacement: nineteen were done for uncontrollable infection; two, for periprosthetic fracture; two, for pain; one, for severe bone loss; and one, for a vascular complication. RESULTS: The twenty-five above-the-knee amputations performed for causes related to the total knee replacement were done at an average of 8.6 years (range, eight days to 23.6 years) after the replacement. The prevalence of above-the-knee amputations done for causes related to total knee replacement was 0.14%. Complications after the above-the-knee amputation included deep infection in five patients and superficial infection and skin necrosis in one each; there was also one perioperative death. Nine of the twenty-five limbs were fitted with an above-the-knee prosthesis, but only five patients were walking even to a limited degree with the prosthesis at the time of the last follow-up. CONCLUSIONS: The overall prevalence of amputation after total knee arthroplasty at our tertiary care center was 0.36%. The majority (63%) of the amputations were performed for reasons not attributable to complications of the arthroplasty. The functional outcome after amputation performed above a total knee replacement is poor. A substantial percentage of the patients were never fitted with a prosthesis, and those who were seldom obtained functional independence.     

Results of amputation for gangrene in diabetic and non-diabetic patients. Selection of amputation level using photoelectric measurements of skin-perfusion pressure

Evaluation was done of 235 patients who had had 273 primary amputations for gangrene. Measurements of local skin-perfusion pressure or systolic blood pressure were made in 222 limbs (188 patients). For the other fifty-one limbs, for which no measurements of pressure were available, the surgeon elected to perform an above-the-knee amputation in nine of seventeen diabetic limbs and a below-the-knee amputation in eight. An above-the-knee amputation was selected by the surgeon for thirty-two of thirty-four non-diabetic limbs and a below-the-knee amputation, for two for which no measurements of pressure were available. Local skin-perfusion pressure was measured distal to the knee before amputation, using a standardized photoelectric technique in 203 limbs and systolic blood-pressure measurements in nineteen. Skin-perfusion pressure was also measured above the knee in seventy-six of the 222 limbs in which a pressure was determined below the knee. These measurements were made available to the surgeon for use as an adjuvant guide to clinical assessment in selecting the appropriate level of amputation. Seventy-four patients (ninety-two amputations) had diabetes and 114 patients (130 amputations) did not. The limbs of the diabetic patients had a significantly higher skin-perfusion pressure at the below-the-knee level (p less than 0.001) than did those of the non-diabetic patients. The ratios of below-the-knee to above-the-knee amputations for the diabetic and non-diabetic patients were 3.8 to one and 1.3 to one (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Malignant tumor of the distal part of the femur or the proximal part of the tibia: endoprosthetic replacement or rotationplasty. Functional outcome and quality-of-life measurements

BACKGROUND: The present study was performed to determine whether there is a difference, with regard to functional outcome and quality of life, between endoprosthetic replacement and rotationplasty for the treatment of malignant tumors of the distal part of the femur or the proximal part of the tibia. METHODS: Sixty-seven patients, between the ages of eleven and twenty-four years at the time of the diagnosis, had a malignant tumor of the distal part of the femur or the proximal part of the tibia. A rotationplasty was performed in thirty-three patients, and an endoprosthetic replacement was done in thirty-four patients. The median duration of follow-up was six years and one month (range, two years to sixteen years and two months). The scale developed by the Musculoskeletal Tumor Society was used to evaluate the functional results. Quality-of-life issues were assessed with the questionnaire developed by the European Organization for Research and Treatment of Cancer. RESULTS: The patients who had had a rotationplasty had a mean functional score, according to the system of the Musculoskeletal Tumor Society, of 24 points, and the patients who had had an endoprosthetic replacement had a mean score of 25 points. This difference was not found to be significant, with the numbers available (p = 0.47). Only one patient who had had a rotationplasty used an assistive device when walking long distances, whereas six patients who had had an endoprosthetic replacement used an assistive device. This difference was significant (p<0.001). The quality-of-life questionnaire revealed that the patients who had had a rotationplasty could participate in hobbies such as carpentry and sports as well as in other daily activities to a significantly greater degree than those who had had an endoprosthetic replacement (p = 0.001). Restriction in daily activities due to pain was significantly less common in the group that had had a rotationplasty than it was in the group that had had an endoprosthetic replacement (p = 0.047). CONCLUSIONS: Rotationplasty was not associated with any disadvantages with regard to function or quality of life in comparison with endoprosthetic replacement. It is possible that the psychosocial outcome is influenced by the fact that patients who have a rotationplasty know that additional operative intervention is not usually necessary. Despite good functional and quality-of-life results, the cosmetic appearance may be the most serious disadvantage of rotationplasty. The decision to perform this procedure must be made on a case-by-case basis.     

Selection of patients for through-the-knee amputation

Forty-six adult patients had a through-the-knee amputation (disarticulation of the knee) in a four-year period. Thirty-four of the patients had peripheral vascular insufficiency and were judged to lack the potential for using a prosthesis functionally, although the evaluation indicated that they had the potential for healing of the wound at the below-the-knee level of amputation. At a minimum follow-up of one year, the amputation wound had healed in thirty of these patients, and no joint contracture had developed. Two patients died in the first postoperative month, and two had failure to heal and needed revision to an above-the-knee amputation. The remaining twelve patients who had a through-the-knee amputation were judged to be potentially able to use a prosthesis functionally, but they did not have the capacity for wound-healing at the below-the-knee level. Therefore, in these patients, a through-the-knee amputation was performed as an alternative to an above-the-knee amputation. The amputation wound healed in eight of these patients, but four (33 per cent) had failure to heal and needed subsequent revision to an above-the-knee amputation. All twelve patients were able to use a prosthesis. The through-the-knee amputation provides good muscular balance and has a low risk for the late development of joint contracture. The residual limb (stump) provides an excellent surface area for sitting balance and a lever-arm for transfer. In a patient who has the potential to use a prosthesis functionally, the residual limb allows direct load-transfer (end weight-bearing).(ABSTRACT TRUNCATED AT 250 WORDS)     

Rotationplasty as a salvage procedure in revision of tumor endoprosthesis of the distal femur – a report of two cases

We performed two rotationplasties (type A1 and A2) as salvage procedures in cases of custom- made endoprosthetic replacements of the distal femur and knee joint. The patients suffered from malignant bone and soft-tissue tumors of the knee, respectively. One of them developed chronic osteomyelitis around both stems of the prosthesis, and three local revisions turned out to be ineffective. The other patient, suffering from parossal osteosarcoma of the distal femur, developed a local recurrence following endoprosthetic reconstruction. The functional abilities following the operation of these two patients suggested that rotationplasty was a viable alternative to above-the-knee amputation in failed or severely complicated total arthroplasty of the knee with massive bone loss. Received: 22 April 1999     

A review of 13-years experience of osteosarcoma

Since the inception of the authors' facility, 365 patients with osteogenic sarcoma have been treated. While other facilities were surgically treating patients with primary amputation, this facility attempted limb-salvage surgery. The majority of patients being treated with limb-salvage surgery had the resected bone replaced by a metallic endoprosthetic replacement. The emphasis on conservative surgery led to the development of growing endoprosthetic replacements with the first being used in 1975. The cumulative survival of those patients with Stage 2 osteosarcoma treated at this facility between 1977 and 1984 is 48% at five years.     

Limb-salvage treatment versus amputation for osteosarcoma of the distal end of the femur

A retrospective multi-institutional study of 227 patients with osteosarcoma of the distal end of the femur was done to compare rates of local recurrence, metastasis, and survival. Three cohorts of patients who had had either a limb-sparing procedure, an above-the-knee amputation, or disarticulation of the hip were compared. The results revealed prevalences of eight of seventy-three, nine of 115, and zero of thirty-nine as to local recurrence; forty-three of seventy-three, sixty-five of 115, and twenty-one of thirty-nine as to metastasis; and thirty-three of seventy-three, forty-eight of 115, and eighteen of thirty-nine as to death. Of the seventeen patients who had a local recurrence, sixteen died. In the limb-salvage group, eighteen patients required amputation, because of local recurrence in eight and other local complications in ten. The Kaplan-Meier estimates of the percentage of patients who survived and the percentage of patients without recurrent disease showed no difference among the three surgical groups (Mantel-Cox test statistic: p = 0.8) after a median length of follow-up of five and one-half years. Various covariant adjusted estimates yielded similar results. For the entire group of patients, the rate of continuously disease-free survival was 42 per cent, and the over-all rate of survival was 55 per cent at five years. It appears that, compared with above-the-knee amputation or disarticulation of the hip, the use of a limb-salvage procedure for osteosarcoma of the distal end of the femur did not shorten the disease-free interval or compromise long-term survival.     

Functional outcomes following trauma-related lower-extremity amputation

BACKGROUND: The principal aims of this study were to examine functional outcomes following trauma-related lower-extremity amputation and to compare outcomes according to the amputation levels. We hypothesized that above-the-knee amputations would result in less favorable outcomes than would through-the-knee or below-the-knee amputations. A secondary aim was to examine the factors, in addition to amputation level, that influence outcome, including the type of soft-tissue coverage, selected patient characteristics, and the technological sophistication of the prosthetic device. METHODS: A cohort of 161 patients who had undergone an above-the-ankle amputation at a trauma center within three months following the injury was followed prospectively at three, six, twelve, and twenty-four months after the injury. The Sickness Impact Profile, a self-reported measure of functional status, was used as the principal measure of outcome. Secondary outcomes included pain; degree of independence in transfers, walking, and climbing stairs; self-selected walking speed; and the physician's satisfaction with the clinical, functional, and cosmetic recovery of the limb. Longitudinal multivariate regression techniques were used to determine whether outcomes differed according to the level of amputation after we controlled for covariates. RESULTS: There was no significant difference in the scores on the Sickness Impact Profile between the patients treated with above-the-knee and those treated with below-the-knee amputation. However, patients with a below-the-knee amputation performed better than did patients with an above-the-knee amputation on the timed test for walking speed (p = 0.04). Patients with a through-the-knee amputation had worse regression-adjusted Sickness Impact Profile scores (p = 0.05) and slower self-selected walking speeds (p = 0.004) than did patients with either a below-the-knee or an above-the-knee amputation. Differences according to the level of amputation were most pronounced for physical function. In general, physicians were less satisfied with the clinical, cosmetic, and functional recovery of the patients with a through-the-knee amputation. Except for problems encountered with insufficient gastrocnemius coverage of the stump in many patients with a through-the-knee amputation, neither the soft-tissue coverage nor the technological sophistication of the prosthesis correlated with outcome. CONCLUSIONS: Severe disability accompanies above-the-ankle lower-extremity amputation following trauma, regardless of the level of amputation. Clinicians should critically evaluate the need for a through-the-knee amputation in patients with a traumatic injury. The results of this study also underscore the need for controlled studies that examine the relationship between the type and fit of prosthetic devices and functional outcomes.     

Procalcitonin as a Biomarker for Predicting Amputation Level in Lower Extremity Infections

Inflammatory markers are essential tools in the decision-making process for lower extremity infections. When coupled with objective findings, clinicians can more accurately diagnose and treat these entities. Typically, markers such as the white blood cell count, erythrocyte sedimentation rate, and C-reactive protein are used to initially assess these patients or monitor the progression of medical or surgical therapy. Procalcitonin is a newer inflammatory marker that is specific for an infectious process. Originally, procalcitonin was used to monitor antibiotic therapy and sepsis for patients in the intensive care setting, but it has now been expanded to other facets of medicine. The utility of procalcitonin has been described for diagnosing infection or osteomyelitis in diabetic foot ulcers. However, limited research has compared inflammatory marker levels and the level of amputation. A retrospective inpatient medical record review was performed of 156 consecutive patient occurrences during 25 months in which surgical intervention was required for a lower extremity infection and an initial procalcitonin level had been obtained. This initial procalcitonin value was then compared with the level of amputation at the final surgical intervention. A highly statistically significant difference was found when comparing those who underwent a below-the-knee or above-the-knee amputation (median procalcitonin 1.72 ng/mL) and those who did not (median procalcitonin 0.105 ng/mL; p < .001). Therefore, patients with higher initial procalcitonin values were more likely to undergo below-the-knee or above-the-knee amputation or require aggressive surgical intervention. Thus, the procalcitonin level can provide valuable initial information to the clinician.     

Clinical implications of combined hypogastric and profunda femoral artery occlusion

From 1983 to 1990, nine patients with combined hypogastric (HA) and profunda femoral arterial (PFA) occlusive disease presented with five nonhealing hip disarticulations, three nonhealing above-the-knee amputations, perineal necrosis in six patients, buttock necrosis in four patients, visceral ischemia in two patients, and lumbosacral spinal ischemia in one patient. Obviously some patients had more than one regional complication. Five patients died from complications of HA/PFA ischemia. Survivors included two patients who required a hemipelvectomy, one patient who required an axillary-to-hypogastric artery bypass graft for stump salvage, and one patient who survived despite lumbosacral paralysis and complete cystectomy. The 56% mortality and 100% morbidity emphasize the critical significance of combined hypogastric/profunda femoral artery circulatory compromise. Efforts should be made to preserve or re-establish the HA and/or PFA circulation whenever possible. A hemipelvectomy may be required to allow the wounds to finally heal. Furthermore, the certainty of an above-the-knee amputation healing is not present in these patients; therefore, a hemodynamic assessment of the healing potential of an above-the-knee amputation is required.     

Function after amputation, arthrodesis, or arthroplasty for tumors about the knee

We studied the function of twenty-two patients who had had a malignant skeletal tumor adjacent to the knee. An above-the-knee amputation was done in seven; a resection arthrodesis, in nine; and a replacement arthroplasty, in six. The patients all walked at a similar speed (sixty-one to sixty-six meters per minute), which is slower than normal (eighty meters per minute). They all walked with comparable efficiency at three velocities: the mean consumption of oxygen was 0.210 milliliter per kilogram of body weight per meter at free velocity, 0.215 milliliter per kilogram of body weight per meter when they walked 25 per cent faster, and 0.211 to 0.240 milliliter per kilogram of body weight per meter when they walked 50 per cent faster. The three groups of patients and a normal control group consumed oxygen at similar rates. The patients who had had an amputation were very active, and they were the least worried about damaging the affected limb, but they had difficulty walking on steep, rough, or slippery surfaces. The patients who had had an arthrodesis had a more stable limb and performed the most demanding physical work and recreational activities, but they had difficulty sitting. The patients who had had an arthroplasty led sedentary lives and were the most protective of the limb, but they were the least self-conscious about the limb.     

Comparative assessment of gait after limb-salvage procedures

We performed metabolic studies of gait in eighteen patients who had had above-the-knee amputation, block resection and arthrodesis of the knee, or block resection and rotationplasty for a malignant tumor of the distal end of the femur or the proximal end of the tibia. According to the measurement of consumption of oxygen, the patients who had had rotationplasty walked most efficiently. Those who had had arthrodesis used more oxygen and walked at a slower rate.     

Custom endoprosthetic reconstruction for malignant bone disease in the humeral diaphysis

The optimal reconstructive method following segmental resection of malignant tumours in the humeral diaphysis is unknown as there are no prospective long-term studies comparing biologic with endoprosthetic reconstruction. This is a retrospective review of 13 patients who, between 1995 and 2010, had undergone limb salvage at our institution using a custom-made humeral diaphyseal endoprosthetic replacement following excision of malignant bone disease. There were 9 males and 4 females with a mean age of 35 years at the time of surgery (range: 10 to 78). Mean follow-up was 56.8 months (range: 5 to 148). Cumulative patient survival was 75% at 10 years. Implant survival, with removal of the endoprosthesis or part of it for any reason as an end point, was 47% at 10 years. Seven patients required revision (54%). Complications included metastases in four, aseptic loosening in four, peri-prosthetic fracture in two and local recurrence in two. Mean MSTS and TESS scores were 23 (18 to 27) and 67% (52-80) respectively. Custom-made humeral diaphyseal replacement following resection of malignant bone tumours provided functional results superior to amputation, without an obvious compromise in patient survival. There was a relatively high revision rate for aseptic loosening and peri-prosthetic fracture and patients should be counselled about this preoperatively.     

The risks and benefits of radiotherapy with massive endoprosthetic replacement

Between 1966 and 2001, 1254 patients underwent excision of a bone tumour with endoprosthetic replacement. All patients who had radiotherapy were identified. Their clinical details were retrieved from their records. A total of 63 patients (5%) had received adjunctive radiotherapy, 29 pre-operatively and 34 post-operatively. The mean post-operative Musculoskeletal Tumor Society scores of irradiated patients were significantly lower (log-rank test, p = 0.009). The infection rate in the group who had not been irradiated was 9.8% (117 of 1191), compared with 20.7% (6 of 29) in those who had pre-operative radiotherapy and 35.3% (12 of 34) in those who radiotherapy post-operatively. The infection-free survival rate at ten years was 85.5% for patients without radiotherapy, 74.1% for those who had pre-operative radiotherapy and 44.8% for those who had post-operative radiotherapy (log-rank test, p < 0.001). The ten-year limb salvage rate was 89% for those who did not have radiotherapy and 76% for those who did (log-rank test, p = 0.02). Radiotherapy increased the risk of revision (log-rank test, p = 0.015). A total of ten amputations were necessary to control infection, of which nine were successful. Radiotherapy may be necessary for the treatment of a bone sarcoma but increases the risk of deep infection for which amputation may be the only solution.     

Energy cost during gait in osteosarcoma patients after resection and knee replacement and after above-the-knee amputation

We determined the energy cost during gait by measuring the oxygen consumption of twenty-six patients after treatment for osteosarcoma about the knee. Fourteen had had an en bloc resection of the distal end of the femur and proximal end of the tibia followed by segmental replacement with a custom-made knee prosthesis and twelve had had an above-the-knee amputation followed by fitting with an artificial limb. Comparisons of free-walking velocity, oxygen consumption per meter traveled, and per cent of maximum aerobic capacity used during walking demonstrated that patients with resection and prosthetic knee replacement had a lower energy cost during gait.     

Transcutaneous oxygen tension as a predictor of success after an amputation

We measured local transcutaneous oxygen tension at the foot and proximal and distal to the knee in 162 patients who then had 206 amputations. When the values for oxygen tension at the foot and distal to the knee were compared with the success or failure of healing after an amputation of the foot or distal to the knee, respectively, a clearly increasing probability of failure was correlated with decreasing transcutaneous oxygen tension. However, even at a tension of zero the probability of failure was not 100 per cent. The results were similar for diabetic and non-diabetic patients. Preoperative values for transcutaneous oxygen tension were a much more consistent predictor of success or failure of healing after an amputation of the foot or distal to the knee than were measurements of systolic blood pressure at the ankle, but neither was predictive of the outcome after an above-the-knee amputation.     

Long-term follow-up after limb salvage in skeletally immature children with a primary malignant tumor of the distal end of the femur

BACKGROUND: Skeletally immature children with a primary malignant tumor in the distal end of the femur are candidates for limb-salvage surgery; however, functional impairment due to subsequent limb-length discrepancy must be considered. Our aim was to evaluate the long-term clinical outcome of limb salvage in patients with a sarcoma of the distal end of the femur who were eleven years old or less, focusing on limb-length discrepancy and complications. METHODS: The cases of forty children were retrospectively reviewed in a multicenter study based on the responses to a questionnaire. Twenty-eight patients had had endoprosthetic reconstruction, and twelve had had biological reconstruction. Functional evaluation was based on the Musculoskeletal Tumor Society scoring system, with numerical values from 0 to 5 points assigned for each of the following six categories: pain, function, emotional acceptance, use of supports, walking ability, and gait. These values were added, and the functional score was presented as a percentage of the maximum possible score. Limb-length discrepancy was measured with orthoroentgenograms. Complications and their treatment were analyzed. Patient survival and the survival of the reconstructions were analyzed with use of the Kaplan-Meier method. RESULTS: Seven patients died and thirty-three remained alive, for a survival rate of 82% at ten years postoperatively. For the surviving patients, the mean follow-up periods (and standard deviations) were similar for the twenty-two who had endoprosthetic reconstruction (13.2 +/- 3.9 years) and the eleven who had biological reconstruction (10.4 +/- 4.4 years). All patients had reached skeletal maturity. The mean final functional score was 74% +/- 18% in the endoprosthetic reconstruction group and 68% +/- 17% in the biological reconstruction group (p = 0.37). For the nineteen patients who underwent limb-lengthening, the mean functional score increased significantly from 65% +/- 21% before the procedure to 81% +/- 11% after the lengthening (p = 0.0016). There were five early and twenty-eight late complications. In the endoprosthetic reconstruction group, the most frequent complications were deep infection and aseptic loosening. In the biological reconstruction group, the most frequent complications were implant breakage and nonunion. Revision surgeries were required in seventeen patients, including five who had an amputation. The rate of survival of the endoprosthetic reconstructions was 77% at five years and 51% at ten years postoperatively, whereas the rate of survival of the biological reconstructions was 46% at both five and ten years postoperatively. CONCLUSIONS: Endoprosthetic or biological reconstructions as limb salvage provided good functional outcome in skeletally immature children with a malignant bone tumor of the distal aspect of the femur despite a high rate of revisions and limb-lengthening procedures.     

Limb-salvage surgery in the treatment of osteosarcoma in skeletally immature individuals

Sacrifice of major growth plates during resection and fixed-length reconstruction of a limb in a skeletally immature child with osteosarcoma may result in a significant limb-length inequality as growth progresses. A limb-length discrepancy in the humerus may cause minor cosmetic problems but does not generally result in a significant functional deficit. In the lower extremity, tumors about the knee, including the distal femur and proximal tibia, usually present the dilemma of whether limb salvage by arthrodesis, osteoarticular allograft, or endoprosthetic replacement would result in a significant limb-length inequality and whether amputation of the extremity is a preferable procedure. The techniques of rotationplasty and an expandable endoprosthesis have been successfully used for treating skeletally immature patients with osteosarcoma of the distal femur. With regard to survival and function, the results obtained with these innovative methods are favorable compared with those of a high above-knee amputation.     

Endoprosthetic replacement for stage IIB osteosarcoma

Over an eight-year period, 100 patients with IIB osteosarcoma have been managed. Eighty-one were treated with limb-salvage procedures, 78 of which involved reconstruction utilizing endoprostheses. Only 19 patients received amputation as the primary treatment for local control. Since 1984, all patients received preoperative and post-operative adjuvant chemotherapy. Those patients who received chemotherapy had a statistically significant improvement in five-year survival over those who did not (57% and 32%, respectively, p = 0.014). The functional results were good overall, with excellent results seen in distal femoral reconstruction. Twenty-eight of the 78 patients treated with endoprosthetic reconstruction experienced 30 complications (36%). Mechanical failure was the most common complication (10%) but was generally correctable. The local recurrence rate was 5% and the infection rate was 3%. Local complications were manageable. A statistical analysis revealed that the relative risk of patient death was 2.5 times higher than prosthesis failure for the 78 patients with endoprosthetic reconstruction. The intermediate-term results, with a median follow-up period of 43 months, remains encouraging.     

Prosthetic usage following major lower extremity amputation

There were 157 patients following major lower extremity amputation who were evaluated to determine functional prosthetic ambulation. Twenty-eight patients were evaluated in the amputee clinic and found not to be candidates for prosthetic fitting. Forty-one patients were fit with a prosthesis but did not become functional prosthetic ambulators. Eighty-eight patients became functional prosthetic ambulators. Of all above-the-knee amputees, 46% became functional prosthetic ambulators. Only 19% of bilateral lower extremity amputees became functional prosthetic ambulators. Of all below-the-knee amputees, 66% became functional ambulators. The presence of coronary artery disease decreased the ambulatory potential in above-the-knee or bilateral amputees but not in below-the-knee amputees. A screening method for elderly, dysvascular amputees should be instituted prior to prosthetic fitting.