Although equinus gait is the most common abnormality in children with spastic cerebral palsy (CP) there is no consistency in recommendations for treatment, and evidence for best practice is lacking. The Baumann procedure allows selective fractional lengthening of the gastrocnemii and soleus muscles but the long-term outcome is not known. We followed a group of 18 children (21 limbs) with diplegic CP for ten years using three-dimensional instrumented gait analysis. The kinematic parameters of the ankle joint improved significantly following this procedure and were maintained until the end of follow-up. We observed a normalisation of the timing of the key kinematic and kinetic parameters, and an increase in the maximum generation of power of the ankle. There was a low rate of overcorrection (9.5%, n = 2), and a rate of recurrent equinus similar to that found with other techniques (23.8%, n = 5).

As the procedure does not impair the muscle architecture, and allows for selective correction of the contracted gastrocnemii and soleus, it may be recommended as the preferred method for correction of a mild fixed equinus deformity.

The results of the Baumann procedure (intramuscular lengthening of the gastrocnemius and soleus in the proximal part of the muscle) for correction of fixed gastrosoleus contracture in diplegic children are presented.

Eleven ambulatory children with diplegic type of cerebral palsy (mean age: 10 years) were operated for correction of fixed gastrosoleus contracture by the Baumann procedure as part of a multi-level, single-session surgery for gait improvement. Evaluation included clinical examination and gait analysis. Mean follow-up after surgery was 2.7 years.

Clinical examination demonstrated significant improvements in active and passive ankle dorsal flexion with maintenance of ankle plantar flexor power. Ankle kinematics showed an increase in the dorsal flexion at initial contact, an average angle in single limb support, and maximum dorsal flexion in swing. Although there was an increase in dorsal flexion at the beginning of push-off, the total range of motion during push-off was not affected. Ankle movement demonstrated better loading in stance, manifested by significant improvement in maximum flexor movement in the second half of single stance. Post-operatively there was a change from abnormal generation of energy to normal energy absorption in mid-stance. Positive action during pushoff was significantly increased.

It is known that the growth of muscle occurs at its musculo-tendinous junction. Anatomic and simulation studies have demonstrated differences in the muscle fasicle length and pennation angles. With the Baumann procedure, an intramuscular lengthening gives the best chance for functional adaptation in the muscle. When needed, the soleus can also be lengthened. Multiple incisions permit stretching of the muscle fibres even in severe deformities.

We treated 22 children (28 limbs) with diplegic cerebral palsy who were able to walk by the Baumann procedure for correction of fixed contracture of the gastrosoleus as part of multilevel single-stage surgery to improve gait. The function of the ankle was assessed by clinical examination and gait analysis before and at two years (2.1 to 4.0) after operation. At follow-up the ankle showed an increase in dorsiflexion at initial contact, in single stance and in the swing phase. There was an increase in dorsiflexion at initial push-off without a decrease in the range of movement of the ankle, and a significant improvement in the maximum flexor moment in the ankle in the second half of single stance. There was also a change from abnormal generation of energy in mid-stance to the normal pattern of energy absorption. Positive work during push-off was significantly increased. Lengthening of the gastrocnemius fascia by the Baumann procedure improved the function of the ankle significantly, and did not result in weakening of the triceps surae. We discuss the anatomical and mechanical merits of the procedure.