In:
Journal of Pediatric Orthopaedics, Ovid Technologies (Wolters Kluwer Health), Vol. 42, No. 3 ( 2022-03), p. 149-157
Abstract:
The correlation between the number, size, and location of cannulated screws and the incidence of avascular necrosis (AVN) in children with femoral neck fractures treated surgically is uncertain. Methods: We retrospectively reviewed 153 children (mean age: 10.6±3.7 y) with femoral neck fractures treated by internal fixation with 2 (n=112) or 3 (n=41) cannulated screws. The severity of initial displacement was divided into incomplete (type I) and complete (type II, angulation 〈 50 degrees; type III, angulation 〉 50 degrees) fractures. The diameter of the screw was measured and recorded as a percentage of the femoral neck width. The distance (D) between the mid-point of each screw at the base (B) of the femoral neck and at the tip (T) of each screw and the superior and anterior cortices of the femoral neck, respectively, were measured on anteroposterior (AP) and lateral (L) radiographs. Values were expressed as the ratio between the measured distance and the width of the femoral neck (BD AP %, TD AP %, BD L %, and TD L %). The correlation between the number, size, and location of the screws and AVN was analyzed. Results: Patients with type II of initial displacement treated with 2 cannulated screws had a lower AVN rate (21.4%) than those treated with 3 screws (44.8%) ( P =0.027). Screw diameter (19%) in patients with AVN was larger than (17%) in patients without AVN ( P 〈 0.001); patients with AVN had a lower BD AP % (48.6%) than those without AVN (56.4%) ( P 〈 0.001). Screw size and BD AP % were risk factors for AVN ( P 〈 0.05). Further, screw diameter 〉 16.5% and BD AP % 〈 51.6% of the femoral neck width were the cutoff values for an increased AVN rate ( P 〈 0.05). Conclusions: Patients treated with 2 cannulated screws showed a lower rate of AVN than patients treated with 3 screws. Screws of larger size and screws closer to the piriformis fossa on AP radiographs increased the risk of AVN in children with femoral neck fractures treated surgically. Level of Evidence: Level III.
Type of Medium:
Online Resource
ISSN:
0271-6798
DOI:
10.1097/BPO.0000000000002018
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2022
detail.hit.zdb_id:
2049057-4
