What modification should i do for these broken edges (red arrow) ?

I don't know why this marked edges are broken. but u see that all other edges are good. After median filtering i applied canny.Now my question is why these are bad ?. I applied another filter but in that these broken edges are good but other edges are broken.So what modification i do so that all horizontal edges will be fine ?

clear; close all;
 global first_comp

%Input Image Raw Depth 512x424
A_depth_distance=imread('C:\Users\sufi\Desktop\matlab_kinect\Data_image\512x424\Best-Dataset\depth\arfin_depth.png');
% A_depth_distance=31.25*uint16(A_depth_distance);
figure,imshow(A_depth_distance,[0 4500]);
title('Input Image Raw Depth 512x424');

%Filtering the raw depth image Median
filtered_depth_distance=medfilt2(A_depth_distance,[3 3]);
figure,imshow(filtered_depth_distance,[0 4500]);
title('Filtering the raw depth image Median');

fill=imfill(filtered_depth_distance,'holes');

%Edge Detection Using Canny Operator
edges_depth_distance=edge(fill,'canny',[0 .009],4);
figure, imshow(edges_depth_distance);
title('Image obtained using Canny Operator');

Broken edges ( red arrow)

Raw Image

[KALYAN ACHARJYA]

Provide the input image.