Heterotopic Ossification Interfering With Lengthening of Magnetically Controlled Growing Rods: A Report of 2 Cases Managed With Excision and a PTFE Liner.

Case: Two pediatric patients with early-onset neuromuscular scoliosis developed heterotopic ossification (HO) on the telescoping hub of magnetically controlled growing rods (MCGR), preventing lengthening. Resection of the circumferential HO and placement of a polytetrafluorethylene (PTFE) liner around the rod restored MCGR lengthening capabilities for 1.3 to 1.5 years after revision surgery, with no HO recurrence.

Conclusion: HO formation surrounding the telescoping portion of the MCGR is a possible cause for failure to lengthen. If found, resection and placement of a PTFE liner can restore MCGR lengthening.

Level Of Evidence: Level IV.