Prosthetic Management of Below-Knee Amputation with Flexion Contracture in the Child

ROBERT E. SCHWARTZ, MD*, WALTHER H. O. BOHNE, MD**, ANDHERBERT E. KRAMER, BS, CPO** New York, New York


Prosthetic management of below-knee or Syme amputation with concurrent knee-flexion contracture has long been problematic, especially in the growing child. A prosthesis has been developed at The Hospital for Special Surgery which not only accommodates the flexed attitude of the amputation limb, but also allows ease of application and adjustments for growth.

T. P. presented to The Hospital for Special Surgery Leg Length Discrepancy Clinic at the age of eight months. Bilateral lower-leg deformities were noted with severe equinovarus positioning of both feet. Radiographs of the limbs revealed type la tibial aplasia of the right tibia (Fig. 1 ) and type 4 tibial hypoplasia of the left tibia3 (Fig. 2 ). At age 18 months, the right fibula was centralized at the knee using Brown's techniques1,2. At age two years, the right knee had a fixed-flexion deformity. A Syme amputation was performed on the right, and the flexion contracture was corrected by an extension osteotomy at the proximal fibula. The flexion deformity recurred, however, and was severe enough at age five to prevent the patient from ambulating with a patellar-tendonbearing Syme prosthesis.

A brace which accommodates the flexion deformity of the knee and the amputation limb was fitted with success (Figs. 3 -4 ). This orthosis was designed and manufactured at The Hospital for Special Surgery, Prosthetics and Orthotics Department.

To allow for the flexion contracture at the knee, the socket was designed to pivot at its proximal attachment to the brace. A strap at the lower end of the socket secures it in maximal possible extension after the brace is applied. Ease of application is aided by a quadrilateral socket which accommodates the flexion deformity of the amputation limb by opening anteriorly and fastening with Velcro straps.

The quadrilateral socket was made height adjustable to allow for some axial growth of the femur before new brace manufacture was necessary. The double upright frame is attached to a SACH foot within the shoe.

With the assistance of this brace the patient was able to ambulate without crutches despite her contralateral deformity which also will require corrective surgery.

Fig. 5 . Child stands in a functionally extended weight-bearing position in spite of the flexion deformity of the amputation limb

* 1380 Northern Boulevard, Manhasset, NY 11030 "The Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021

References:

  1. Brown, F. W.. Construction of a Knee Joint in Cngenital Total Absence of the Tibia (Paraxial Hemimelia Tibia). J Bone Joint Surg 47-A: 695-704, 1965.
  2. Brown, F. W., and W. M. Pohnert: Construction of a Knee Joint in Meromelia Tibia (Congenital Absence of the Tibia). J Bone Joint Surg 54-A: 1333, 1972.
  3. Jones, D., J. Barnes, and G. C. Lloyd-Roberts: Congenital Aplasia and Dysplasia of the Tibia with Intact Fibula: Classification and Management. J Bone Joint Surg 60-B: 31-39, 1978.