Conus medullaris injury from burst fractures is known to occur in conjunction with other neurological deficits, including lower-extremity motor weakness or sensory changes. Rarely does an isolated conus medullaris injury occur from an extradural cause without other neurological deficits. The authors report four cases of L-1 burst fractures in which conus medullaris dysfunction was the sole neurological injury in the absence of lower-extremity involvement.