Lower limb amputation in children: report and experience in 21 cases

Abstracts

Os autores apresentam os resultados de 21 pacientes, com idade média de 6 anos, submetidos à 26 amputações do membro inferior por malformações congênitas (14), infecções (06) e outras. Discute-se os procedimentos, as complicações, as vantagens e desvantagens de cada nível de amputação. Concluem que a amputação na criança continua sendo uma opção a ser considerada, principalmente por propiciar rápida recuperação funcional e social do paciente.

ARTIGO ORIGINAL

Lower limb amputation in children. Report and experience in 21 cases

William Dias Belangero^I; Bruno Livani^II, Alessando Janson Angelini^III; Michael Davitt^IV

^IProf. Dr. Department Coordinator of DOT/HC/UNICAMP

^IIPost-Graduate student and Orthopedic Surgeon of DOT/HC/UNICAMP

^IIIPost-Graduate student and Orthopedic Surgeon of DOT/HC/UNICAMP

^IVOrthesis and Responsible for Orthesis and Prosthesis Unity

SUMMARY

It is reported the experience in 21 patients, average age of 6 years old, who were submitted to 26 lower limb amputation due to congenital malformation (14), infection (6) and others. It is discussed the procedures, complications, advantages and disadvantages of each amputation level. It is concluded that amputation in children is still an option to be considered, mainly for allowing the patent a rapid recovery both functional and social.

INTRODUCTION

Even considering that the same basic technical principles of amputation in adults are also used in children, there are some important differences that should be highlighted. Children, differently from adults, can tolerate tensioned suturae and skin grafting over the stump, present a smaller number of complications ⁽⁷⁾, as well as phantom pain and development of neuromae virtually do not exist at this age level^(1,2,3). On the other hand, differently from adults, children may present instability or even patellar dislocation in amputations below the knee. Patellar elevation induced by the use of PTB prosthesis in children may be avoided by the use of adequate sockets for a more uniform distribution of weight. ⁽⁶⁾. This presentation aims to discuss aspects as those related to indications, and functional amputation levels for lower limb amputations in children.

CASES AND METHOD

Between January/1990 and January/2000, 26 amputation were performed in 21 children. The ages ranged from 09 months to 16 years (average 6 years), with an average follow-up of 4.5 years (range 1-10 years). Fourteen amputations were due to congenital abnomarlities, 6 due to infection, 1 to trauma and 5 due to other causes (vasculitis, fulminant purpura and 3 due to neurofibromatosis). The amputation level was: 1 toes disarticulation, 2 knee disarticulation, 7 Syme’s disarticulation and 16 transtibial amputation (Table 1).

Two patients (cases 14 and 16) with transtibial amputation needed stump revision respectively 2 and 5 years after surgery. This was necessary to remove distal exostosis and percutaneous osteotomy of tibia for correction of antecurvatum, which were interfering in prosthesis adaptation.

Case number 11 was the only one in this series who was submitted to amputation at medium level of the leg bones (transtibial) with a bone bridge according to Ertl’s ⁽⁴⁾ technique.

DISCUSSION

Lower limb amputation in children may be an excellent treatment alternative for complex deformities, for avoiding to submit the patient to multiple surgical procedures with results that can be sometimes frustrating.

Rapid post surgery recovery, and good adaptability to prosthesis should be taken into consideration for early indication of this procedure. Prosthesis should be adapted as soon as cicatrization and stump adaptation. During immediate post-operative period would be advisable the use of a dressing with plaster, which could be splited into two valves if necessary. Once cicatrization is obtained, the stump should be involved in an elastic bandage for reducing edema and molding it, allowing better prosthesis adaptation.

When planning an amputation, the maximum length of the limb should be preserved and, whenever possible, growing plates should as well be preserved. The presence of the epiphysis avoids terminal bone growing caused by neo-formed bone tissue aggregation, which has no relationship to growing plate activity of proximal stump extremity. This phenomenon is more frequently observed in the humerus, fibula, tibia and femur (in this frequency order) and, for not being influenced by the growing plate, epiphysiodesis is not indicated. ⁽⁷⁾. Even though a transtibial amputation may result in this overgrowing, this is not an acceptable reason for sacrificing the limb length and perform, for example, a knee disarticulation. In this series, from the 16 transtibial amputation, with a mean follow up of 5 years, only two (cases 14 and 16) needed a surgical review of the stump. The preservation of knee joint, even with a short stump is justified in children, since there is a good growing potential due to the proximal tibial physis, which is responsible for 60% of the total growing of this bone (Figure 1). Besides this, gait of children with knee disarticulation, even being acceptable in moderate activities, is worse for activities eliciting larger physical performance, as racing and sports practicing ⁽⁵⁾.

In transfemoral amputations we believe that the same doesn’t happens, since proximal physis of femur is responsible only for 30% of the final length of this bone, being sometimes necessary surgical procedures for increasing stump length.

Considering foot amputation, toes disarticulation and transmetatarsal amputations are procedures offering good functional results, while amputations at Chopart and Lisfranc joint levels can develop equino-valgus deformity, so being of better indication Boyd’s amputation or Syme’s disarticulation (Figure 3). In this group of cases, we decided for Syme’s disarticulation, for we are more familiar to the technique and for considering more difficult to get a fusion between calcaneal bone and tibia in lower aged children, who have large amounts of cartilaginous tissues in their bones. Theoretically, Boyd’s amputation brings more advantages for preserving the calcaneal bone, so giving a stump with a final length closer to the normal side. ⁽⁷⁾. However, when this fusion does not occur, the calcaneal bone tends to a equinous deviation, so making difficult walking without prosthesis and prosthesis adaptation.

In those patients who underwent Syme’s disarticulation, there were no difficulties for prosthesis adaptation because in 4 the preoperative diagnosis was Fibular Agenesia with lateral maleolar atrophy, and in case number 4, with a diagnosis of neurofibromatosis. Time evolution lead to a remodelation of the maleoli, which allowed not only weight bearing without prosthesis, but also a good prosthesis adaptation. (Figure 2)

In 1949 Ertl described a technique of using a bone bridge in transtibial amputation. ⁽⁴⁾. This technique has the advantage of allowing a stump with terminal weight bearing, since the union between the bones increases the weight bearing area and makes the distal end of the stump more rigid and firm, in a similar fashion to the obtained in disarticulation, so reducing overgrowing complications. ^(7). Besides this, closing the medullar channel avoids intraosseous pressure reduction and distal stump osteopenia as well as limiting adduction/abduction fibular movement during walking, which produces flaccid stumps. Among us this technique is being divulged by Pinto et alli. ^(8).

In this group of cases, only case 11 (Figure 1) underwent bone bridge and, even though the follow up is of only 1 year, it can be noticed the painless terminal weigh bearing. All the patients above the age of 10 report to be satisfied with functional and esthetic results of amputation, and do not regret the procedure.

We would like to remark that some patients underwent several surgical procedures attempting salvation of heavily compromised limbs. Many times these procedures request a long term follow-up, making these children to "loose" their childhood and teenage times, so compromising their life quality, with important emotional, psychological and educational consequences. It is the role of Orthopedic Surgeon to analyze critical and individually each case, weighting the risks and benefits that salvation procedures can bring when compared to limb amputation and early rehabilitation.

REFERÊNCIAS

• 1. AITKEN, G. T., and Frantz, C.H.: The juvenile amputee, J. Bone Joint Surg. 35-A:659,1953.
• 2. AITKEN, G.T.: Amputation as a treatment for certai lower extremity congenital abnormalities. J.Bone Joint Surg. 41-A:1267,1959.
• 3. AITKEN, G.T.: The child Amputee. Orthop. Clin. North Am. 3:347,1972.
• 4. ERTL, J.: Uber Amputationstumpfe. Chirurg 20:218, 1949
• 5. LODER, R.T. & HENRY, J.A.: Desarticulation of the knee in children: a functional assessment. J.Bone Joint Surg. 69 A: 1155, 1987.
• 6. MOWERY, C.A.; HENING, J.A. & JACKSON, D.: Dislocated pathella associated with below-knee amputation in adolescent patients. J. Pediatr. Orthop. 6: 299, 1986.
• 7. MÜLLER, G.: Amputation in children. In: Treatment of fractures in children and adolescents. BG Weber; CH. Brummer & Frauler, F. Springer Verlag, Berlin, 1980. .
• 8. PINTO, M.A.S; FILHO, N.A; GUEDES, J.P.B e YAMAHOKA, M.S.O: Ponte Óssea na amputação transtibial. Rev. Bras. Ortop. 33 (07): 525-531, 1998.

Publication Dates

• Publication in this collection
  20 Feb 2006
• Date of issue
  Sept 2001