Indications for gastrocsoleus lengthening in ambulatory children with cerebral palsy: a Delphi consensus study

Abstract

Purpose: Equinus is the most common deformity in cerebral palsy (CP) and gastrocsoleus lengthening (GSL) is the most commonly performed surgery to improve gait and function in ambulatory children with CP. Substantial variation exists in the indications for GSL and surgical technique. The purpose of this study was to review surgical anatomy and biomechanics of the gastrocsoleus and to utilize expert orthopaedic opinion through a Delphi technique to establish consensus for surgical indications for GSL in ambulatory children with CP.

Methods: A 17-member panel, of Fellowship-trained paediatric orthopaedic surgeons, each with at least 9 years of clinical post-training experience in the surgical management of children with CP, was established. Consensus for the surgical indications for GSL was achieved through a standardized, iterative Delphi process.

Results: Consensus was reached to support conservative Zone 1 surgery in diplegia and Zone 3 surgery (lengthening of the Achilles tendon) was contraindicated. Zone 2 or Zone 3 surgery reached general agreement as a choice in hemiplegia and under-correction was preferred to any degree of overcorrection. Agreement was reached that the optimum age for GSL surgery was 6 years to 10 years and should be avoided in children aged under 4 years. Physical examination measures with the child awake and under anaesthesia were important in decision making. Gait analysis was supported both for decision making and for assessing outcomes, in combination with patient reported outcomes (PROMS).

Conclusions: The results from this study may encourage informed practice evaluation, reduce practice variability, improve clinical outcomes and point to questions for further research.

Level of evidence: V.

Keywords: cerebral palsy; consensus; equinus; gastrocsoleus lengthening; surgical indications.

Fig. 1.

Surgical anatomy of the gastrocsoleus muscle-tendon unit. Zone 1 extends from the origin of the gastrocnemius to the termination of the muscle fibres of the medial bely. There is a surgical plane between the two muscles, which can be used to recess the gastrocnemius alone or to lengthen the two muscles by different amounts. The Strayer distal gastrocnemius recession is illustrated in (a) and the Strayer plus SFL is illustrated in (b). Zone 2 is the conjoined tendon of the gastrocnemius aponeurosis and the soleal fascia. The modified Vulpius gastrocsoleus recession (GSR) is illustrated in (c). Zone 3 is the Achilles’ tendon. The White slide TAL is illustrated in (d), two transverse partial tenotomies with the anterior fibres cut distally (dotted line) and medial fibres cut proximally. For more detail see reference 13.

Fig. 2.

The body support moment, drawn after Winter. The body support moment, which maintains upright posture during stance phase, is the sum of the moments from the gastrocsoleus, quadriceps and hip extensors. The gastrocsoleus contributes most to the body support moment.

Fig. 3.

The sagittal plane motors for the lower limb. Of the three muscle groups that contribute to the body support moment, only the gastrocsoleus is commonly lengthened.

Fig. 4.

Zone 1 surgery in diplegia. Sagittal ankle and knee kinematics in a ten-year-old boy with asymmetric spastic diplegia before, 12 months and five years after Single-Event Multilevel Surgery (SEMLS). On the right side (solid line) the equinus was more severe and the surgery chosen was Strayer +SFL. On the left side (dotted line) the equinus was mild, the Silverskiold test indicated a contracture of the gastrocnemius but not the soleus. A Strayer procedure was performed. Surgery at the knee level was medial hamstring lengthening and transfer of rectus femoris to the semitendinosus. The grey band indicates the laboratory normal reference range. The Gait Profile Score (GPS) and GVS values are above each kinematic trace. A decrease in GVS and GPS indicates an improvement. The minimum clinically important difference for GPS is 1.6 degrees. Stance phase dorsiflexion was improved at 12 months with further improvements at five-year follow-up with no further intervention. Note the improvement in ankle dorsiflexion in swing phase at five-year follow-up with restoration of first rocker.