Journal of the Pediatric Orthopaedic Society of North America (Nov 2024)
Weight Percentile Is Maintained During Spica Casting: A Retrospective Cohort Study of Patients Treated with Closed or Open Reduction for Developmental Dysplasia of the Hip
Abstract
Background: Weight changes during spica casting previously have not been reported. The primary aim of this study was to determine weight percentile change from cast initiation to cast removal. Secondary aims were to assess weight percentile changes from initiation to mid-term follow-up visits after cast removal and to assess the mean weight change from cast initiation to cast removal. Methods: Patients with developmental dysplasia of the hip (DDH) treated with closed or open reduction (± femoral/pelvic osteotomy) and spica cast were retrospectively reviewed from 2/2016–6/2023. Patients aged <4 years treated for ≥6 weeks in spica cast were included. Patients lacking weight measurements within the 4 weeks prior to cast initiation or within 2 weeks following cast removal were excluded. Demographics, weight, and weight percentiles at cast initiation, cast removal, and at follow-ups were collected. Mean weights and mean weight percentiles were compared across visits with dependent sample t-tests and one-way analysis of variance tests based on normality, with a significance threshold of P ≤ .05. Results: Thirty-six hips in 31 infants (median age: 10.4 [interquartile range {IQR}: 9, 16.3] months, 86% female) were included. The median duration of casting was 9.2 [IQR: 7.9, 12.6] weeks; 2 hips had midpoint cast change. The mean weight was 9.8 ± 2.3 kg at cast initiation and 10.1 ± 1.9 kg at final cast removal, with a mean change of 0.3 ± 0.4 kg (P = .527). Mean weight percentiles did not differ during or after treatment (range: 55-61st percentile, P = .974). Conclusion: Weight percentiles were maintained during spica casting in the patients examined in this study, which should be reassuring to the family and treatment team; our study did not find that spica casting stunts weight gain. For surgeons who may consider maintaining the original spica cast throughout treatment, without cast change, a mean weight gain of 0.3 kg for a mean casting length of 9 weeks in infants of median age 10.4 months should be reassuring; many infants/toddlers may not require a cast change due to growth. Key Concepts: (1) Spica casting does not appear to stunt weight gain. (2) The weight percentile did not change during spica casting following open or closed reduction for developmental dysplasia of the hip. (3) The mean weight gain during typical spica casting is 0.3 kg, which was not statistically significant. Level of Evidence: III, retrospective cohort
