Multilevel Surgery for Equinus Gait in Children with Spastic Diplegic Cerebral Palsy

Abstract

as magnetic resonance imaging (MRI) or 3D ultrasound are costly, require specialist expertise, and take a long time to perform and process. These limitations may explain, in part, why the measurement of muscle volume has not yet transi-tioned into clinical practice or been included in large-scale clinical trials. To date, research studies of muscle volume in CP have low numbers of participants or are restricted to one or two muscles. Therefore, for larger research studies to be performed, and for muscle volume to become a routine clinical assessment, a new clinically feasible approach for measuring muscle volume is required. The work of Schless et al. 5 suggests that muscle volume may be estimated from measurements made using a standard two-dimensional (2D) ultrasound scanner. Schless et al. reported a strong linear relationship between muscle volume and the product of muscle length and cross-sectional area in the medial gastrocnemius. 5 This strong relationship has implications for the clinical feasibility of assessing muscle volume in this group. However, the work described is not a complete test of the utility and accuracy of estimating muscle volume by 2D ultrasound. The measurements of muscle length and anatomical cross-sectional area were made using a 3D ultrasound system. It cannot be assumed that by using a 2D method in isolation the relationship would be as strong as Schless et al. report. The authors identified the muscle insertion and musculo-tendinous junction from within a reconstructed 3D data set postdata collection. This has the advantage of allowing longitudinal reconstructions of the whole muscle length to be viewed, which greatly aids in identifying muscle end points. In practice, a 2D assessment would involve measurement of muscle length by tape measure guided by live 2D ultrasound imaging, and the identification of an optimal ultrasound image from which to estimate the anatomical cross-sectional area. Variation in probe location, orientation, and surface pressure are all likely to increase variability in the data set. Therefore, this 2D technique for estimating muscle volume is likely to have lower repeatability compared to MRI and 3D ultrasound techniques. However, accepting a suboptimal 2D technique that is simple, realistic, and feasible may be the way forward to enable large scale research studies to be performed and ultimately for a routine clinical assessment technique to be developed. The authors use an unconventional definition of the prox-imal origin of the medial gastrocnemius at the tibia, rather than utilising the real anatomical origin at the formal con-dyle. Although this limitation is unlikely to have a significant impact on the strength of the relationship between muscle volume and the product of muscle length and cross-sectional area, the regression equation developed by the authors is only valid for measurements made following the same definition. Furthermore, the findings of Schless et al. may not be generalisable to other muscles. Further investigation of the reliability ...

Abnormality of standing posture improves in patients with bilateral spastic cerebral palsy following lower limb surgery

“…Our improvement in mGPS was smaller than values reported in the literature. Lehtonen et al [31] found a change of 3.5 degrees five years post operatively and Frith [11] found changes of 5.9 and 6.6 degrees at 12-18 months and 7.5 years after surgery respectively. However both these studies included subjects who were not able to walk independently (GMFCS levels III).…”

“…Interventions may include lengthening of musculo-tendinous units, tendon transfers, rotational and displacement osteotomies and stabilization of the hip and foot [6]. A recent systematic review [7] identified numerous retrospective [8][9][10][11][12][13] and prospective studies [14][15][16][17][18][19] demonstrating improvements in gait, gross motor function and quality of life following orthopaedic intervention. 3D gait analysis is commonly used to inform surgical decision making [20][21][22].…”

“…A number of indices have been proposed in the literature to measure gait abnormality, including the Gillette Gait Index (GGI) [23], Gait Deviation Index (GDI) [24] and Gait Profile Score (GPS) [25]. The Gait Profile Score (GPS) [25][26][27] is a well-validated index commonlyadopted as an outcome measure for orthopaedic intervention [11,[14][15][16][17]28]. Thomason et al [14,15] reported improvements in gait and gross motor function at 1, 2 and 5 years post-operatively using a range of gait indices.…”

“…Rutz et al [17] found that patients with greater preoperative gait abnormality had the most significant improvements in GPS, with a mean improvement of 4.3°. In a retrospective study of 40 children with BSCP and an equinus gait, Firth et al [11] showed GPS improved by an average of 6.6 degrees 7.5 years after multi-level surgery.…”

Reproducibility of an instrumented measure for passive ankle dorsiflexion in conscious and anaesthetized children with cerebral palsy

“…In spastic diplegia, optimal sagittal balance suggests that 'a little equinus is better than calcaneus' and proposes that the most conservative gastrocnemius lengthening procedure be undertaken to achieve 5°ankle dorsiflexion with the knee extended. 20 In a systematic review of the reliability of threedimensional gait analysis measurements, it was suggested that 'errors in excess of 5°should raise concern and may be large enough to mislead clinical interpretation'. 21 Together, these arguments strengthen the proposal for a MCID of 5°for PADKE in children with CP.…”