WASHINGTON (AP) — The Food and Drug Administration said Friday that more than 300 spinal surgical instruments recalled last week by Zimmer Holdings Inc. could potentially cause serious injury or death.

Zimmer announced Dec. 20 it was recalling 315 Peek Ardis Inserters after reports that the devices could cause surgical delays and injury when used with in spinal surgery. The Warsaw, Ind., company said too much force on the Inserter could cause another implant to break during surgery, potentially damaging the cover of the spinal cord, or causing blood loss or nerve injury.

FDA issued a statement Friday saying it classified the company’s action as a Class I recall, meaning patients treated with the devices could be seriously injured or die.

The agency notes that the recalled device is an essential part of Zimmer’s Peek Ardis Implant System, which “will be unavailable for use until a redesigned inserter is cleared by the FDA.”