Figure 5.

Histologic findings. A: Hematoxylin and eosin staining of the fracture site and adjacent area in both phosphate-buffered saline (PBS) and NELL-PEG groups. At the final time point of the treatment (week 4), PBS group shows nonunion of the callus with fibrocartilaginous remnants at the fracture site. Dashed lines represent the cortical border of radius. Black boxed areas denote perifracture areas, and red boxed areas denote midcallus areas. Boxed areas in top panels are shown at higher power magnification in middle and bottom panels. B: Histologic assessment was based on Allen's scoring system for fracture healing.¹⁸ The PBS group shows three of seven samples fail to form a union at week 4, whereas all samples in the NELL-PEG group are healed. Original magnification: ×4 (A, top panels); ×20 (A, middle and bottom panels).