Proximal Femur Guided Growth for the Management of Hip Dysplasia in Children with Cerebral Palsy

Abstract

Proximal femoral deformity associated with neuromuscular hip dysplasia in children with cerebral palsy (CP) is characterized by increased anteversion, coxa valga, and caput valgum. Guided growth of the proximal femur (PFGG) utilizes a screw to tether the medial portion of the physis to achieve progressive varus alignment of the femoral head and neck with subsequent growth. This procedure has been shown to decrease the head shaft angle and Reimer’s migration percentage (RMP); and decrease the need for subsequent skeletal hip reconstructive surgery. The indications, surgical technique, post-operative management, potential pitfalls of this relatively new procedure are reviewed.

Guided Growth of the Proximal Femur for the Management of the ‘Hip at Risk’ in Children with Cerebral Palsy—A Systematic Review

“…Davids [35] has published a detailed technical summary of TMH-PF and has identified guided growths as a minimally invasive, safe and effective treatment options for CP patients with hip dysplasia. Most patients in the reported studies [32,34,47] were between 4 and 12 years of age and had a GMFCS of III-V; however, TMH-PF was performed in GMFCS I and II children by others [46].…”

“…This can justify extended hip surveillance into adulthood and surgical intervention in selected cases [55]. Apart from GMFCS, Davids recommends an MP of 25 to 50% and an age between 4 and 10 years as indications for this guided growth procedure, and it was hypothesized that early surgical treatment is associated with greater potential for improvement of hip valgus; however, the likelihood of screw revision surgery due to the physis growing off the screw (whereby the screw no longer crosses the physis) is also increased [35]. A recent publication from the Cerebral Palsy Integrated Pathway Scotland (CPIPS) database concluded that the 'point of no return' for hip subluxation in this population was a MP > 46%, making spontaneous improvement unlikely [56]; however, others advocated a lower threshold for surgical intervention [12].…”

“…Our inclusion criteria were pediatric, skeletally immature patients with cerebral palsy, as described and updated by Bax et al [39,40]; and a "hip at risk" of progressive subluxation, as described by Davids et al and others [12,35].…”

“…Anterior hemiepiphysiodesis of the distal femur has been shown to be effective in the treatment of fixed flexion deformity of the knee when compared to traditional osteotomies [26][27][28][29][30]. Figure 1 shows intra-operative radiographs of this minimally invasive technique, which has been recently applied to the proximal femoral physis for various conditions [23,[31][32][33][34][35]. By placing a screw over the physis on the medial side, the tethering that occurs on the medial side will result in progressive varus of the proximal femur.…”