Overgrowth after femoral shaft fractures in infants treated with a Pavlik harness

Risk factors for femoral overgrowth after femoral shortening osteotomy in children with developmental dysplasia of the hip

Objective

Developmental dysplasia of the hip (DDH) refers to a series of deformity of acetabulum and proximal femur and abnormal relationship between them, it represents the most common hip disease in children. Overgrowth and limb length discrepancy (LLD) was common complication in children undergoing femoral shortening osteotomy. Therefore, the purpose of this study was to explore the risk factors of overgrowth after femoral shortening osteotomy in children with DDH.

Methods

We included 52 children with unilateral DDH who underwent pelvic osteotomy combined with femoral shortening osteotomy between January 2016 and April 2018, including seven males (six left and one right hip) and 45 females (33 left and 12 right hips) with an average age of 5.00 ± 2.48 years, and an average follow-up time of 45.85 ± 6.22 months. The amount of overgrowth and limb length discrepancies (LLDs) were calculated. The risk factors of femoral overgrowth ≥1 cm and LLD ≥ 1 cm were analyzed.

Results

There were statistical differences in age (p < 0.001) and operation duration (p = 0.010) between the two groups with femoral overgrowth <1 cm and ≥1 cm. There was a statistical difference in operation duration (p < 0.001) between the two groups. Age (p < 0.001) was an independent influencing factor of femoral overgrowth in children with unilateral DDH after pelvic osteotomy and femoral shortening osteotomy, and a risk factor (p = 0.008) of LLD in these children.

Conclusion

The overgrowth and LLD of children with developmental dislocation of hip after pelvic osteotomy and femoral shortening osteotomy are significantly related to age. There was no significant difference between different pelvic osteotomies for femoral overgrowth in children. Therefore, surgeons should consider the possibility of LLD after femoral shortening osteotomy in children of a young age.

Leg-length discrepancy and associated risk factors after paediatric femur shaft fracture: a multicentre study

PURPOSE

This study was performed to investigate leg-length discrepancy (LLD) and associated risk factors after paediatric femur shaft fractures.

METHODS

A total of 72 consecutive patients under 13 years old (mean age 6.7 years; 48 boys, 24 girls) with unilateral femur shaft fracture, and a minimum follow-up of 18 months, were included. The amount of LLD was calculated by subtracting the length of the uninjured from that of the injured limb. Risk factors for an LLD ≥ 1 cm and ≥ 2 cm were analyzed using multivariable logistic regression analysis.

RESULTS

Hip spica casting, titanium elastic nailing and plating were performed on 22, 40 and ten patients, respectively. The mean LLD was 7.8 mm (sd 8.8) and 29 (40.3%) had a LLD of ≥ 1 cm, while nine (12.5%) had a LLD of ≥ 2 cm. There were significant differences in fracture stability (p = 0.005) and treatment methods (p = 0.011) between patients with LLD < 1 cm and ≥ 1 cm. There were significant differences in fracture site shortening (p < 0.001) and LLD (p < 0.001) between patients with length-stable and length-unstable fractures. Fracture stability was the only factor associated with LLD ≥ 1 cm (odds ratio of 4.0; p = 0.020) in the multivariable analysis.

CONCLUSION

This study demonstrated that fracture stability was significantly associated with LLD after paediatric femur shaft fractures. Therefore, the surgeon should consider the possibility of LLD after length-stable femur shaft fracture in children.

LEVEL OF EVIDENCE

Prognostic level III.