Complete Longitudinal Deficiency of the Fibula: Comparison of Foot Ablation to Retention in Long-Term Follow-Up

ROBIN C. CRANDALL, MD*Minneapolis, Minnesota


The fibula is the most frequently missing long bone. Longitudinal deficiency of the fibula is termed complete longitudinal deficiency of the fibula or paraxial fibular hemimelia. Coventry and Johnson' classify three main types. Type One patients present partial unilateral absence and minimum leg length discrepancy. Type Two is the typical bowing of the tibia with shortening of the tibia and femur, and a variable number of absent missing rays. Type Three individuals have bilateral anomalies or other, congenital deformities involving the extremities. Many children with fibular absence can walk without surgical intervention. Maldevelopment of the foot (Fig. I ) and bowing of the tibia, however, often make ambulation impossible. Kruger and Talbot3 report that children with normal appearing feet often have the most severe types of shortening. Early ankle disarticulation has been proposed as the treatment of choice with this anomaly. The amputation is particularly recommended when bowing of the tibia exists, dysplasia of the foot is problematic, or significant shortening exists. It has also been pointed out that designing adequate prostheses to accommodate the maldeveloped foot can be particularly difficult and that these unconventional prostheses often are unacceptable to the patient. It is difficult to find longterm follow-up studies of individuals who have retained the foot.

The purpose of this study is to review the experience at the Minneapolis Shriners Hospital for Crippled Children regarding individuals who have had foot ablation and those who have had retention of the foot and unconventional fitting. It is the desire to compare "how good is good" so that a rational decision can be made regarding surgical recommendations.

Materials and Methods

Fifty-three individuals with a diagnosis of complete longitudinal deficiency of the fibula are currently seen at the Minneapolis Shriners Hospital for Crippled Children. After rejecting cases where follow-up was inconclusive or too brief, and where the individuals had proximal femoral focal deficiency, the study consisted of 39 individuals, having 44 affected limbs. Five patients had bilateral anomalies; the others were equally divided between right and left-sided deficiency. Of the bilateral cases, four were seen in young men. All tolled, men presented thirty limbs, including seventeen foot ablations: ten ankle disarticulations and seven below-knee amputations. Thirteen who retained the foot had unconventional fittings, including nonstandard prostheses on seven (Figs. 2A and 2B ) and six with various types of lifts.

Thirteen young women were studied. Seven were treated with foot ablation, including four ankle disarticulations and three below-knee amputations. The others wear nonstandard prostheses or shoe lifts. Of the 39 patients studied, 22 were seen and followed from the first year of life with only six patients being seen initially after age four. Patients were analyzed carefully for follow-up with the average being 9.4 years. Charts, records, and examinations were reviewed on all individuals. Other anomalies appear in Table 1 .

Analysis of Cost

A primary goal of this study was to analyze patient cost with respect to conventional and unconventional fitting. It has been frequently argued that unconventional fitting is more costly and that this is one of the proposals for requiring an ankle disarticulation-type prosthesis. Prostheses at the Minneapolis Shriners Hospital for Crippled Children are made by private practitioners in Minneapolis and Saint Paul, because the hospital does not have "in-house" facilities. Ankle disarticulation and below-knee prostheses cost $91,043 over the period analyzed, with the average expense per prosthesis being $591. Forty-eight unconventional fittings amounted to a total dollar expenditure of $25,968, with an average cost per prosthesis of $541. The analysis was based on ten patients, seven male and three female, who were fit with unconventional appliances. Unconventional fittings were slightly less expensive when analyzed over the same period.

Number of Clinic Visits

The number of clinic visits was compared with respect to unconventional and conventional fittings. It has often been argued that individuals with unconventional amputations frequently have more limb complaints, skin disorders, and prosthetic problems requiring an increased number of clinic visits. The unconventional group had 162 visits over 49 patient years, an average of 3.4 visits per year. The ankle disarticulation group had 271 visits over 124 years, 2.2 visits per year. The group of patients treated with below-knee amputation surgery required 359 visits over 117 patient years or 3.1 visits per year. These data suggest that unconventionally fit individuals do indeed require more visits, approximately an increase of 1.2 visits per year as compared with the ankle disarticulation group.

Ulceration

Amputation limbs were analyzed with respect to ulceration and other difficulties. The below-knee amputation group had the highest proportion of breakdown; four limbs had significant cutaneous ulcerations; this represent 40 percent of those individuals with below-knee amputations. Those with ankle disarticulations had a much lower incidence of limb problems; only two persons reported difficulties. This represents 14 percent of the entire group. It is interesting to note that in the unconventional fittings, no incidences of skin breakdown occurred, although various sores formed especially over the area of the great toe, the lateral ray, and occasionally over the tibial prominence. These areas, however, were easily relieved by modifications of the prosthesis, one of the reasons for the increased number of prosthetic visits per year by the unconventional wearers. Formal surgical revisions were necessary in seven cases, primarily the below-knee amputees.

Patient Satisfaction

Most patients either with or without foot ablation were satisfied. In the male population, there were 26 patients with 30 amputation limbs. In this group, seventeen underwent foot ablations, including seven below-knee amputations in the older patient population. Below-knee amputations were only done prior to the usage of ankle disarticulation. All patients with foot ablation were satisfied. Seven patients were fit in unconventional fashion and six with simple shoe lifts. One man with an unconventional fitting was dissatisfied. He underwent surgery involving leg lengthening and shoe lift fitting. The surgery was fraught with complications, the overall lengthening was not appropriate, and the fitting was unsatisfactory. Several young men cited advantages to the retention of their foot. One was a place kicker on a football team who noted also that swimming was certainly no problem with retention of the foot. Virtually all who did not undergo foot ablation could ambulate easily at home without a prosthesis. Patients with ankle disarticulation tended to depend on their prosthesis.

Three young women were fit with unconventional prostheses and two with simple lifts. All patients with foot ablation were satisfied. Several had foot ablation because of cosmetic considerations. Unconventional fitting tends to have major cosmetic drawbacks. One unconventionally fitted individual specifically stated that she was not satisfied with this approach and would have surgery. Two bilaterally involved patients needed no fittings or surgery whatsoever because of relative leg length equality (Figs. 3 and 4 ).

Conclusions

These data suggest that unconventional fitting is an appropriate treatment option even in the more severe forms of complete longitudinal deficiency of the fibula. Careful consideration is necessary prior to any foot ablation. There was no increased incidence of prosthetic costs or lack of patient satisfaction. An increased number of visits per year were necessary in the unconventional wearer. Patients who retained their foot ambulate very well at home without the need for a prosthesis. Specific activities, including swimming and kicking, may be enhanced in individuals with foot retention. The main problem in analyzing this group of patients is how to deal with the statement "how good is good" or "how excellent is excellent." Advocates of ankle disarticulation state that this is the treatment of choice.2,4-6 This claim, however, may also apply to non-ablated individuals treated on a more conservative program. Certainly it is important to realize that cosmetic considerations have been major factors for female patients and that individuals with severely dysplastic feet with or without severely bowed tibiae, should certainly undergo foot ablation. It was noted in one young woman that the cosmetic consideration was of major importance in her dissatisfaction with the unconventional device. Currently at the Minneapolis Shriners Hospital for Crippled Children, we take a relatively conservative approach on foot ablation. We do not have a reflex action to ablate the foot in all individuals with complete longitudinal deficiency of the fibula. We prefer to wait and see. Certainly we do not feel it is mandatory to perform surgery prior to age four. In an individual with severe dysplasia and severe bowing with poor function of the residual foot, ablation is absolutely necessary. If ablation is done, ankle disarticulation is, without question, the treatment of choice. In male patients, however, we have found that retention of the foot has been a viable option. Families are presented with the data in a straight forward manner and are allowed to select the treatment options. They are shown individuals with retention of the foot and others with ablation of the foot and the prostheses involved. Individuals with bilateral anomalies often need no surgery or prosthetic fitting since relatively equal leg lengths are present.

Acknowledgment

Sincere appreciation is accorded Elaine Nordahl for help in preparation of this manuscript.

*Shriners Hospital for Crippled Children, 2025 East River Road, Minneapolis, MN 55414

References:

  1. Coventry MB, Johnson EW: Congenital Absence of the Fibula. Journal of Bone and Joint Surgery 34-A:941-955, 1952.
  2. Davidson WH, Bohne WH: The Syme Amputation in Children. Journal of Bone and Joint Surgery 57-A:905-909, 1975.
  3. Kruger LM, Talbot RD: Amputation and Prosthesis as Definitive Treatment in Congenital Absence of the Fibula. Journal of Bone and Joint Surgery 43-A:625-642, 1961.
  4. Mazet R Jr: Syme's Amputation: A Follow-up Study of Fifty-one Adults and Thirty two Children. Journal of Bone and Joint Surgery 50-A:1549-1563, 1968.
  5. Westin GW Sakai DN, Wood WL: Congenital Longitudinal Deficiency of the Fibula: Follow-up Treatment by Syme Amputation. Journal of Bone and Joint Surgery 58-A:492-496, 1976.
  6. Wood WL, Zltosky N, Westin GW: Congenital Absence of the Fibula: Treatment by Syme Amputation. Journal of Bone and Joint Surgery 47-A:1159-1169, 1965.