Pediatric floating knee injuries: Clinical modifiers affecting sports and transfer outcomes.

Abstract

This study assessed the functional outcome, and the clinical modifiers that influence them with the aim to assist the clinician plan a better management strategy in Paediatric Floating Knee (PFK) injuries. A quasi-prospective, single-center observational study was designed to determine the functional and radiological outcomes in children (</= 16 years), with minimum 1 year follow-up after treatment for PFK from 01-01-2014 to 01-08-2019. A retrospective audit was conducted, and a prospective patient/parent reported outcome score was determined with the Pediatric Outcome Data Collection Instrument (PODCI) questionnaire for 'transfer and mobility' and 'sports and physical function'. Of 32 patients with PFK injury, twenty-five patients with a mean follow-up of 43 months (SD = 18) who completed the PODCI questionnaire were analysed. Fourteen (56%) children had open fractures (Lett's D or E types) with 6 open femur and 12 open tibia fractures. Majority underwent surgical fixation, 8 children required staged reconstruction and 11 children required soft tissue procedure in the ipsilateral limb. The mean time to union for femur and tibia fractures was 3.86 months (SD = 5.3) and 3.5 months (SD = 2.9), respectively with delayed union/non-unions in 3 femoral and 4 tibial fractures. The mean knee range of movement (RoM) was 102° (SD = 34.1) with limb shortening in 6 children, and overgrowth in 3 children. The mean normative PODCI (transfer) score was 35.6 (normal range: -74 to 52) and mean PODCI (sports) score was 37.6 (normal range: -33 to 56). Both the PODCI scores demonstrated strong inverse correlation with higher ISS(p < 0.01) and > 4 cm of bone loss (p < 0.01) but poor correlation with age at injury (p = 0.5), open fracture (p = 0.17), comminuted femoral and/or tibial fracture patterns (p > 0.05) and loss of soft tissue cover (p = 0.08). Early recognition of clinical modifiers such as high ISS and bone loss > 4 cm warrants targeted limb reconstruction strategy and can help to prognosticate outcome.