Treatment of hallux deformities in adolescents with cerebral palsy MARYSE BOUCHARD Department of Orthopedics and Sports Medicine, Seattle Children’s Hospital, Seattle, WA, USA. doi: 10.1111/dmcn.13775 This commentary is on the original article by van de Velde et al. on pages 624–628 of this issue. Hallux valgus and hallux flexus, or ‘dorsal bunion’, can develop in adolescents with cerebral palsy (CP). The preva- lence of these deformities is unknown and there is scant liter- ature on treatment outcomes. Typically, primary arthrodesis is recommended over joint sparing techniques for severe symptomatic hallux deformities in patients with CP. 1,2 The article by van de Velde et al. is the largest retrospective cohort review on hallux valgus and hallux flexus in patients with CP to date. They report on the radiographic and clinical characteristics of 41 patients identified through a state-wide CP register who underwent first metatarsophalangeal joint (MTPJ) arthrodesis over a 21-year period. The prevalence of hallux deformity requiring arthrodesis was 1.8%. 3 Most importantly, they noted patients with hallux valgus deformities were ambulant teenagers with spastic type CP, who functioned in Gross Motor Function Classification System (GMFCS) level II or III, and frequently had soft- tissue releases for equinovalgus and knee and hip contrac- tures. In contrast, the patient cohort with hallux flexus was non-ambulatory with dystonia type disorders, was slightly older at presentation (17y vs 15y 11mo), considered in GMFCS level IV or V, and more commonly underwent scoliosis or hip reduction surgery. Some patients in the lat- ter group had concurrent hallux valgus and hallux flexus. A recent study by Bayhan et al. 4 reviewed joint sparing pro- cedures for hallux valgus in 25 children (39 feet) with CP and had good results at a mean of 14.6 months follow-up with two revisions. Interestingly, the children in this cohort were also in GMFCS level II or III. One patient was in level I. Although biomechanical studies have shown that the fore- and hindfoot can compensate after an MTPJ arthrodesis and allow for near-normal gait, 5 this may not be possible in patients with CP who have spasticity and muscle imbalance. We cannot extrapolate from van de Velde et al.’s study if gait was improved or impeded after MTPJ arthrodesis, though we can assume concerns of pain and shoe wear were most likely resolved. These studies might behoove the orthopedist to consider joint sparing surgeries for isolated hallux valgus deformity in ambulatory, high functioning patients with CP, with the understanding that recurrence risks are likely higher and revision surgeries may be required. In contrast, as van de Velde et al.’s study suggests hallux flexus occurs in non-ambulatory patients with more severe muscle imbalance and dystonia, MTPJ arthrodesis should remain a primary treatment for this deformity. Recurrence rates would be lower, more aggressive correction can be achieved, especially in children with concurrent flexus and valgus, and the potential postoperative changes in gait mechanics would be less important in this population. This is a well-conducted retrospective study though it has inherent limitations. The registry did not allow for identification of patients with hallux deformities who did not require arthrodesis. The natural history, prevalence, and outcome of joint-sparing surgical intervention of milder deformities are not known. There is no information on the surgical techniques employed for arthrodesis. It is unknown whether these surgeries were performed concur- rently with procedures to address other foot or lower limb deformities, which is important for ensuring success of MTPJ realignment. Although the paper discusses assess- ment of preoperative radiographic deformity, there is no mention of postoperative correction achieved, fusion rates, or patient outcomes. Future research should include description of the natural history of hallux deformities in CP, and use of patient reported outcome scores, such as the pediatric-validated Oxford Foot and Ankle Score, to better understand the impact of these deformities pre- and postoperatively. Long-term studies comparing joint sparing techniques and MTPJ arthrodesis for hallux valgus and flexus in patients with CP are needed, and patient cohorts should be strati- fied by GMFCS level and ambulatory status. REFERENCES 1. Jenter M, Lipton GE, Miller F. Operative treatment for hallux valgus in children with cerebral palsy. Foot Ankle Int 1998; 19: 830–5. 2. Davids JR, Mason TA, Danko A, Banks D, Blackhurst D. Surgical management of hallux valgus deformity in chil- dren with cerebral palsy. J Pediatr Orthop 2001; 21: 89– 94. 3. van de Velde SK, Cashin M, Johari R, Blackshaw R, Khot A, Graham HK. Symptomatic hallux valgus and dorsal bunion in adolescents with cerebral palsy. Dev Med Child Neurol 2018; 60: 624–8. 4. Bayhan IA, Kadhim M, Sees JP, et al. Hallux valgus deformity correction without fusion in children with cerebral palsy. J Pediatr Orthop B 2017; 26: 164–71. 5. Brodsky JW, Baum BS, Pollo FE, Mehta H. Prospective gait analysis in patients with first metatarsophalangeal joint arthrodesis for hallux rigidus. Foot Ankle Int 2007; 28: 162–5. 542 Developmental Medicine & Child Neurology 2018, 60: 532–542