WASHINGTON?Doctors are closely monitoring retired Army Gen. Henry H. Shelton, a former chairman of the Joint Chiefs of Staff, to determine whether he needs spinal cord surgery, a spokeswoman for Walter Reed Army Medical Center said Thursday.

Shelton, who initially was partially paralyzed when he fell off a ladder at his suburban Virginia home Saturday, remains in serious condition in the hospital’s intensive care unit, Beverly Chidel said.

“We just don’t know” whether his injury will require surgery, she said, and Shelton probably will remain in the hospital through the weekend.

Shelton is having no difficulty breathing or speaking, doctors say.

Shelton, 62, served 38 years in the Army, including four as the top military adviser to the president. He stepped down as Joint Chiefs chairman Oct. 1, shortly before the United States went to war in Afghanistan.