Selection of Patients
A review of the medical records of the patients from the study by Herring et al.15 showed that twelve of the fourteen patients who had had a Syme amputation for the treatment of fibular deficiency were more than eighteen years old at the time of our review. For all twelve patients, the indication for the amputation had been a severe deformity of the foot (the foot was not plantigrade because of equinovalgus of the ankle) or the absence of at least two rays, or both. The deformity usually was associated with appreciable shortening of the limb (five centimeters or more, which suggested that there would be substantial shortening at the completion of growth) at the time of the initial evaluation. Thus, there were no specific criteria; rather, there was a subjective perception by the treating physician that the cumulative deformity was too severe to be amenable to reasonable reconstructive capabilities at the time of the assessment.
All twelve patients were contacted and were asked if they would participate in a follow-up assessment of their physical and psychological functional status. Ten patients agreed to participate in the study, and the other two patients were interviewed by telephone only. The study was approved by the Research Review Committee of the Texas Scottish Rite Hospital for Children and by the University of Texas Southwestern Medical Center Institutional Review Board for the Use of Human Subjects. All subjects gave informed consent.
Evaluation Protocol
The evaluation of the ten patients comprised four major categories: physical examination, prosthetic assessment, psychological testing, and physical performance testing.
Physical Examination
Each patient was interviewed and examined by one of us (J. G. B., S. J. W., or J. M. S.). The historical review focused specifically on physical activity, level of limitations, problems with the stump (for example, skin irritation or breakdown, or painful end-bearing in or out of the prosthesis), any problems with the affected limb, and subsequent treatment of either lower extremity after the amputation. The physical examination was performed to assess the alignment of the lower limb in and out of the prosthesis, the range of motion and stability of the joints of the lower extremity, the condition of the residual limb, instability or deformity of the knee, evidence of heel-pad migration from the weight-bearing end of the residual limb, problems with the skin of the residual limb, and the gait while the patient wore the prosthesis.
Prosthetic Assessment
The prosthetic assessment was performed by one of us (D. C.) and consisted of an interview with the patient followed by an assessment of gait, the condition of the residual limb, and the condition of the prosthesis. The primary purpose of the assessment was to determine if the amputation, the prosthesis, or the patient's access to prosthetic care had an influence on the patient's ability to pursue his or her goals and interests. We recorded the number and type of prosthetic fittings and replacements that each patient had had since the last evaluation at our institution, and we asked about their concerns regarding access to prosthetic fittings as adults.
Psychological Testing
The battery of psychological tests consisted of the Wechsler Adult Intelligence Scale-Revised (WAIS-R)29, the Quality of Life Questionnaire (QLQ)8, and the Tennessee Self-Concept Scale-Revised (TSCS-R)27.
The WAIS-R is an individually administered instrument that is used to assess intellectual functioning29. It is the most widely researched and commonly used intelligence scale for patients between the ages of sixteen and seventy-four years. The test provides an overall intelligence-quotient score in addition to intelligence-quotient scores representing the subject's performance in verbal and psychomotor skills.
The QLQ is a 192-item self-reporting instrument designed to assess the subject's so-called quality of life across a broad range of specific areas8. The instrument provides a single overall score that represents the subject's global assessment of quality of life. The QLQ's content scales also measure fifteen specific areas: material well-being, physical well-being, personal growth, marital relations, parent-child relations (excluded from the present analysis as only one individual had children at the time of the evaluation), extended-family relations, extramarital relations, altruistic behavior, political behavior, job characteristics, occupational relations, job satisfiers, creative/aesthetic behavior, sports activities, and vacation behavior. This instrument is also sensitive to the subject's attempt to give socially desirable responses.
The TSCS-R is a 100-item self-reporting instrument designed for patients who are twelve years of age or older27. It is an accepted research and clinical tool that provides a multidimensional description of self-concept, including the following basic scales: identity, self-satisfaction, behavior, physical self, moral-ethical self, personal self, family self, and social self. The TSCS-R also contains scales that assess emotional and social maladjustment, including general maladjustment, psychosis, personality disorder, neurosis, and personality integration.
The patients' mean scores on each of the psychological tests were compared with normative data, provided by the publishers of the tests, in order to determine if they differed significantly.
Physical Performance Testing
Physical performance was tested with use of a Cybex-II isokinetic dynamometer (Lumex, Ronkonkoma, New York). Cybex designed an attachment to enable the testing of children (that is, patients with shorter limbs). To ensure a secure and snug fit, the pediatric attachment was used on the involved side, and washcloths were wrapped around the residual limb if it was small.
The isokinetic muscle test consisted of knee extension and flexion at a speed of 60 degrees per second for both the involved and the uninvolved limb. This speed was chosen on the basis of the recommendations of Cybex. The uninvolved limb was tested first. Before the test was conducted, the patient was allowed to warm up and practice at the test speed. For testing purposes, the patient performed eight to ten maximum repetitions. The maximum torque was measured (in foot-pounds) in both extension and flexion. The results for the knee of the affected limb were compared with those for the contralateral knee.
One of the ten patients who agreed to participate in the physical assessment and psychological testing did not complete the psychological testing. The two patients who participated in a telephone interview but did not return for physical and psychological assessment reported no problem with the prosthesis or with function.
The ages of the ten patients (eleven limbs) at the time of the Syme amputation ranged from two years and five months to twelve years and four months (mean age, 7.4 years) (Table I). There were seven male patients and three female patients. At the time of this study, the patients ranged in age from eighteen years and two months to twenty-six years and six months (mean age, twenty-one years and eight months). Six patients had involvement of the right limb, three had involvement of the left limb, and one (Case 6) had involvement of both limbs. The patient who had bilateral involvement had bilateral Syme amputation, at the ages of ten and eleven years, after having had numerous procedures in an attempt to salvage limbs with severe foot and ankle deformities in the absence of major limb-length inequality. Two patients also had congenital anomalies of the upper extremities.
Physical Examination
All ten patients who were examined had alignment of the lower extremity that was within normal limits, both in and out of the prosthesis. The femorotibial alignment averaged 4 degrees of valgus (range, 0 to 10 degrees of valgus). Nine of the ten patients had a normal gait clinically while wearing the prosthesis. One patient (Case 3) had a slightly antalgic gait associated with a mildly tender callosity over the anterior aspect of the proximal part of the tibia, but she had no additional problems with the affected extremity. This patient also had recurrent symptomatic patellar instability on the contralateral side, which was treated nonoperatively. One patient (Case 8) had a mildly positive Lachman sign, indicating laxity of the anterior cruciate ligament; he complained of minor, intermittent episodes of instability, or giving-way, of the knee. He had no appreciable pain or effusion and no history of falls, and he had not sought treatment for this condition.
Five patients (including Case 3) reported no difficulty with the involved limb since the time of the Syme amputation and had had no additional operative procedures. Four patients had had a total of six additional operative procedures after the Syme amputation, each of which required a mean of three days of hospitalization. Three patients (Cases 2, 4, and 6) had had a medial distal femoral or proximal tibial hemiepiphyseodesis to correct genu valgum that had interfered with prosthetic fitting. One of these patients (Case 6) also had had reconstruction with an autologous patellar ligament graft because of laxity of the anterior cruciate ligament. He reported that he had no symptoms of instability or effusion, and he had a stable knee and essentially a full range of motion on clinical examination. Another patient (Case 5) had revision of the stump because of tenderness associated with retained calcaneal fragments; this procedure was performed concomitantly with a tibial osteotomy for the treatment of residual anteromedial bowing of the tibial diaphysis.
No patient had breakdown of the skin on the residual limb at the time of the examination. Three patients (Cases 1, 3, and 5) had mild migration of the heel pad: two had posterior migration and one, lateral migration. However, none of these patients were symptomatic, and the migration did not appear to affect their ability to bear weight on the end of the residual limb, either in or out of the prosthesis. Two patients (Cases 1 and 3) had a callosity over the anterior aspect of the tibia, and it was mildly tender in one of them (Case 3). One patient (Case 8) had a nontender callosity over the medial malleolus.
The two patients (Cases 6 and 9) who had congenital anomalies of the upper extremities were able to function well without the need for an upper-extremity prosthesis or assistive device.
Prosthetic Assessment
All twelve patients had an appropriate, functional Syme prosthesis as determined by examination (ten patients) or as reported to us by telephone (two patients). No patient reported difficulty with walking or running while wearing the prosthesis. No patient had to function without a prosthesis at any time after the operation, other than as required to repair the device or because of temporary problems with the stump.
Of the ten patients who were examined, five reported that they were able to tolerate full distal loading without the prosthesis in order to walk short distances (for example, to enter or exit a shower or pool). Four patients reported that they could tolerate distal loading with the prosthesis but could not walk without the prosthesis. Only one patient was unable to tolerate distal pressure because it was painful. With the exception of this patient, all patients wore a prosthesis that had a firm distal pad to facilitate some distal loading within the prosthesis.
All ten patients wore a self-suspending prosthesis that utilized the malleoli to keep the device on. Several strategies were used for suspension. These included the use of a removable molded pad that fit over the residual limb, a built-in flexible pad that compressed as the patient pushed the limb into the socket, and a compressible liner. Several limbs were sufficiently nonbulbous to enable the prosthesis to be donned simply through compression of soft tissue around the malleolus and the heel pad. No prosthesis required so-called windows to facilitate suspension. This is probably because the residual limbs in the study group were not as bulbous distally compared with those of adults with normal malleoli who have had a Syme amputation. Except for the prosthesis worn by the patient who had had bilateral amputation, whose limbs matched each other, most of the prostheses were slightly larger in circumference at the ankle compared with the circumference of the normal ankle. Three patients had mild posterior or lateral migration of the heel pad, but this did not create any problem with fitting or the stump.
When asked about any consistent problems related to the amputation or the prosthesis, all patients reported occasional minor skin irritation, including folliculitis, that resolved either spontaneously or after treatment with topical antibiotic treatment and prosthetic adjustment to relieve pressure. All patients stated that the most frustrating problem regarding the prosthesis was the frequent need to repair or replace the prosthetic foot because materials had worn out over time or keels or ankle bolts had broken.
When asked if the amputation or the prosthesis had ever limited their ability to participate in an activity, seven patients said that it had not. Nine patients reported participation in recreational sports both as children and as adults. Two had played high-school football. Two patients responded that, on rare occasions, they had been unable to run in physical education class or football practice because the prosthesis either was being repaired or was being modified to relieve a pressure area. One patient stated that he had been unable to enlist in the air force because of the amputation but that he had subsequently earned a private pilot's license.
The ability to pay for and receive prosthetic care was a concern of all patients; however, nine patients had been able to obtain funding through private insurance, employment-related policies, or state rehabilitation agencies. New prostheses cost between $5000 and $9000 in the private sector and last for approximately five years. The one patient (Case 6) who did not have funding for a new prosthesis at the time of the study had lost a number of funding sources because of sociopathic behavior as an adolescent. He was noncompliant with the requirements of the state rehabilitation agency and was not covered by any employer-related medical insurance. This patient had repaired his two Syme prostheses by himself a number of times (for example, by splinting a broken prosthetic ankle with fiberglass and spokes from a motorcycle). Despite the lack of professional attention to the prostheses for more than five years, this patient was managing a cattle ranch, loading bales of hay, and practicing karate.
Psychological Testing
Nine of the ten patients completed the entire battery of psychological tests. One patient completed the TSCS-R but refused to complete the remaining tests, saying that the questionnaires were intrusive.
Wechsler Adult Intelligence Scale-Revised (WAIS-R)
The WAIS-R revealed a mean full-scale intelligence quotient (with standard deviation) of 104 ± 17.8 points, a mean verbal intelligence quotient of 110 ± 18.1 points, and a mean performance intelligence quotient of 105 ± 18.0 points; with the numbers available for study, we could not detect any significant difference between these scores and the expected mean score (100 ± 15.0 points) of the normative sample. The patients' full-scale intelligence quotients ranged from 80 points (considered low-average) to 134 points (considered very superior). The patients' skills in the verbal and nonverbal domains showed similar amounts of variance; their verbal intelligence quotients ranged from 79 to 136 points, and their performance (nonverbal) intelligence quotients ranged from 87 to 125 points.
Quality of Life Questionnaire (QLQ)
The normative mean score (with standard deviation) on the QLQ was 50 ± 10 points. Subjects' scores that are one standard deviation higher or lower than the normative mean score are considered significant (p < 0.05) and may be clinically meaningful. A clinically meaningful score indicates that most (84 percent) of the individuals in the normative sample achieved a score that was higher or lower than that achieved by the patients in our sample. Analysis of these scales with use of a two-tailed, one-sample t test indicated that the patients' mean scores on the creative/aesthetic behavior subscale (t [2,8] = 2.32, p < 0.05) and the vacation behavior subscale (t [2,8] = 2.42, p < 0.05) were significantly different from those of the normative sample but were not clinically meaningful; that is, the patients' scores on these two subscales were not sufficiently different to allow us to conclude that their self-ratings were considerably different from those of most individuals in the normative sample. With regard to all other subscales on the QLQ, our sample was not found to be significantly different from the normative sample, with the numbers available (Table II).
A tendency toward lower quality-of-life scores was noted for one patient who was divorced and had divorced parents and for another patient who had divorced parents.
Tennessee Self-Concept Scale-Revised (TSCS-R)
The normative mean score (with standard deviation) on the TSCS-R also was 50 ± 10 points. According to the TSCS-R manual, scores of 65 points or more are considered high and clinically meaningful, whereas scores of 35 points or less are considered low and clinically meaningful27. Although a two-tailed, one-sample t test revealed a significant difference between the mean score for our sample and the normative mean on the identity subscale (t [2,9] = 2.43, p = 0.038), the difference was within one standard deviation of the mean and therefore was not clinically important. There was no significant or clinically important difference between the scores for our sample and the normative scores on any other subscale. Although there was some degree of variability on the adjustment subscales, all patients scored average or high (Table III). On the maladjustment subscales, all subjects scored average or low, except for one patient who scored high on the psychosis subscale. Some investigators have found ethnic differences in scores on some of the subscales27.
The adjustment subscales reflect various facets of an individual's self-esteem, including perceived self-identity, level of self-acceptance, view of physical appearance and health, satisfaction with involvement in religion, sense of self-worth, sense of perceived worth as a family member, and sense of adequacy in relation to other people. The maladjustment subscales are psychopathological indices, including psychosis, personality disorder, neurosis, and personality integration (that is, level of adjustment and functioning) and are useful for distinguishing patients who have psychiatric disorders from those who do not27.
Physical Performance Testing
During one visit, the patients were tested for knee extension and flexion strength. They were asked to maximally perform six repetitions on the Cybex-II dynamometer. The three repetitions that demonstrated the greatest strength, and that varied from one another by less than 10 percent, then were chosen. If the patient did not achieve such repetitions, the test was repeated only once so as not to introduce the fatigue factor. Only the maximum three repetitions were reported.
In the nine patients who had unilateral fibular deficiency, the maximum torque strength of extension of the affected knee averaged 63 percent (range, 42 to 114 percent) of that of the unaffected, contralateral limb and the maximum torque strength of flexion averaged 73 percent (range, 49 to 103 percent) of that of the unaffected, contralateral limb (Table IV).
The one patient (Case 3) in whom the maximum torque strength of both flexion and extension of the affected knee was greater than that of the contralateral knee had had recurrent patellar dislocations of the contralateral knee. If her test results are excluded, the mean extension strength of the affected knee was 61 percent (range, 42 to 80 percent) and the mean flexion strength was 71 percent (range, 49 to 96 percent).
All knees had a clinically normal, full range of motion.
Fibular deficiency is a congenital disorder characterized by variable shortening of the limb, deformity of the foot and joints, and fibular hypoplasia. Several classification schemes have been developed in an attempt to quantify the severity of the deformity primarily according to the extent of the fibula that is present1,6,11. Clinical decisions regarding treatment are made mainly on the basis of limb-length inequality and the severity of the deformity of the foot19-22.
For many years, Syme or Boyd amputation in early childhood has been recommended to replace the deformed foot with a more functional prosthetic one, to simplify the treatment of limb-length inequality, and to avoid subjecting the child to multiple reconstructive operations. However, recent advances in reconstructive techniques, afforded by the introduction of Ilizarov's method and apparatus, have resulted in renewed interest in the reconstruction of limbs that have deformities associated with fibular deficiency4,5,10.
There are few long-term clinical data concerning the results of either approach to this particular limb deficiency. In a previous study from our institution, which provides free orthopaedic and prosthetic care to children, favorable clinical results were reported after Syme amputation in children15. In the present investigation, we sought to assess patients from that earlier study, who initially had been diagnosed with fibular deficiency and were no longer being managed at our institution, to determine whether the continuing need for prosthetic fitting interfered with their function and aspirations as young adults.
The psychological outcome data on this group of patients support the idea that adults who have had a Syme amputation in childhood perform as well as the average adult on measures related to intelligence, quality of life, self-concept, and psychological adjustment. Although our subjects actually evaluated themselves slightly more positively on the identity subscale27 than did the normative sample and rated themselves higher on the creative/aesthetic behavior subscale8, the difference between their mean scores on these subscales and the normative scores was not considered to be clinically meaningful. Also, although these patients had taken slightly fewer vacations than had the normative sample, according to the vacation-behavior subscale, this difference was not clinically meaningful.
We did observe a tendency toward lower quality-of-life scores for one patient who was divorced and had divorced parents and for another patient who had divorced parents. Because of the small sample size, we were not able to analyze this possible relationship statistically; however, this finding suggests possible avenues for future research.
Overall, these patients were not limited in their ability to pursue and achieve personal goals or to maintain a good quality of life. Clinicians working with patients who are facing amputation should be aware of these findings when making recommendations to parents and patients.
The results of isokinetic muscle-testing with the Cybex-II dynamometer showed generally good preservation of knee strength and motion after Syme amputation. We believe that other authors will need to account for loss of strength or motion as part of their final assessment of adults who have had other reconstructive procedures. The results of the present study can be used for comparisons in future studies of adults who have had limb-lengthening for the treatment of fibular deficiency during childhood.
The patients in the current study generally led active, productive lives and had always done so. All of the patients had an appropriate, functioning Syme prosthesis, and all were employed or attending school, or both. Most had been active in sports, including competitive high-school athletics. The two patients who qualified for but did not participate in this study also had a functioning prosthesis; one worked full time, and the other worked part time and attended school part time.
Boyd amputation has been recommended by some authors to prevent posterior slipping of the heel pad, which occurs frequently after Syme amputation21. Although variable slipping of the heel pad was noted in three patients, it did not appear to contribute to any prosthetic or other functional problem.
Both the amputation and the prosthesis had caused occasional inconvenience to most of these patients, and continued use of a Syme prosthesis always requires financial and insurance planning. Although most of the patients expressed some concern regarding the cost of future prosthetic requirements, at the time of this writing none had been without a prosthesis at any time other than that needed for repair.
In conclusion, our study shows that a small group of young adults who had a Syme amputation apparently were not limited in their ability to pursue and achieve their personal goals. On the basis of our interpretation of the results and our clinical experience with reconstructive procedures at our institution, we consider limb reconstruction only for patients who have a good foot (one with at least three rays and a stable ankle mortise) and for whom shortening of the entire affected limb is projected to be less than approximately 20 percent. Limb salvage is considered only after the family has been advised of the treatment alternatives of limb-lengthening and Syme amputation and has been provided with an opportunity to attend both juvenile-amputee and Ilizarov clinics.
NOTE: The authors thank Daniel R. Faber, B.S., whose diligent editing efforts were crucial to the successful completion of this article, and dedicate this work to his memory.