During explanting Univers II or Apex, is it necessary to remove both inferior and superior screws to disengage from the stem?

During explanting Univers II or Apex, is it necessary to remove both inferior and superior screws to disengage from the stem?

• A. No
• B. Yes
• C. Only inferior screws
• D. Only superior screws

Answer: (A)

Think of the Univers II and Apex implants as having a neck that locks to the stem with locking screws. To disengage the neck from the stem, you only need to release that locking mechanism by removing the screws that cross-lock the neck to the stem. You do not have to take out both the inferior and superior screws to separate the components. Once the locking screws are removed, the neck and stem can be separated with gentle distraction and controlled manipulation. The remaining screws aren’t required for the disassembly, though you would address any bone in-growth or debris as part of the overall explant technique.

Think of the Univers II and Apex implants as having a neck that locks to the stem with locking screws. To disengage the neck from the stem, you only need to release that locking mechanism by removing the screws that cross-lock the neck to the stem. You do not have to take out both the inferior and superior screws to separate the components. Once the locking screws are removed, the neck and stem can be separated with gentle distraction and controlled manipulation. The remaining screws aren’t required for the disassembly, though you would address any bone in-growth or debris as part of the overall explant technique.