Occurrence and Factors Predisposing to Lower Limb Length Discrepancy Following Treatment of Paediatric Femoral Shaft Fractures With Early Spica Cast at the Kenyatta National Hospital

Abstract

Background: No local studies have examined the prevalence and factors predisposing to lower limb length discrepancy following treatment of paediatric femoral shaft fractures with early spica cast. The present study was carried out at the Kenyatta National Hospital to fill this gap. Methodology: This was a cross-sectional analytical study design that enrolled 35 paediatric patients (aged 3 months to 5 years). The participants were recruited through consecutive sampling. The independent variables were the patient’s body mass index and fracture pattern as classified under AO-Muller/Orthopaedic Trauma Association (AO/OTA) system. The intermediate variable was the spica cast application method. The dependent variable was lower limb length discrepancy. The patients were recruited into the study at the time of spica cast removal. Their weight and height was measured, and their body mass index (BMI) was calculated. The fracture type was classified according to AO/OTA classification using the injury radiograph from the patient’s file. Clinical limb length was measured for each limb and compared. Data analysis: Descriptive were presented using charts, tables, and graphs. Pearson chisquare was used to examine the relationship between BMI and LLLD, while spearman’s correlation was used for examining that between AO/OTA fracture type and LLLD. Results: There was a 100% response rate. The ages ranged from 24 months to 42 months with an average of 34.8 months. More females (54%) than males (46%) affected. The average BMI was 14.1, and none of the patients were noted to be obese when matched to BMI-for-age percentile. Majority (57.2%) were found to be in the underweight category. The most common AO/OTA classification fracture types were 3, 2, A2 at 37.1% (n=13); followed by 3, 2, A3 at 22.9% (n=8); 3, 2, A1 at 17.1% (n=6); and 3, 2, B2 at 11.4% (n=4). LLLD was present in 48.6% (n=17) of the cases, with only one participant having clinically significant shortening (2 centimetres). There was no statistically significant association between the BMI in percentiles and the LLLD (Chi-square value 13.673, D.F-26, P-value 0.997). There was no relationship between BMI and presence or absence of LLLD (OR- 1.38: Value 0.208). There was no statistically significant correlation between the fracture type classification and lower limb length discrepancy (Spearman’s rho -0.173, P-value 0.32). Conclusion: Treatment of paediatric fractures of the femur with spica casting at KNH is generally satisfactory with respect to lower limb length discrepancy.