Perhaps a zipper put in the underarm seam of the sleeve would help. My SIL broke his leg in an accident at work and had the external rods and pins from the hip to the ankle. He wore loose shorts that I put in a seperating zipper in the outside seam. I put the clasp end at the waist line so that it would zip DOWN the leg. That way as the hardware was removed, he could zip it down more to close the pantleg. His doctor said he had never seen it done like that but wished I lived closer to the hospital because he would send patients my way for alterations. I hope your husband does well in his recovery.