A growing spinal rod system is configured to grow in response to the growth of a patient. The growing spinal rod system includes a housing, a spacer, and a sliding spinal rod. The housing includes a stepped passage therethrough. The spacer is disposed within the stepped passage and defines a through hole. The spacer includes a plurality of ribs biased inwards and into the through hole. The sliding spinal rod is slidably inserted through the through hole of the spacer. The sliding spinal rod moves the plurality of ribs outwards. The plurality of ribs permits the sliding spinal rod to extend from the housing and inhibit the sliding spinal rod from retracting into the housing.