Abstract
Introduction
There is no doubt that the future of limb lengthening lies with internal lengthening. Complication rates are reduced and patient satisfaction is increased. The evolution of internal lengthening peaked with the dual direction, easily inserted and externally controlled PRECICE Nail. It has excelled in performance in accuracy and satisfaction. Its versatility increased with smaller sizes and increased excursion. A field safety notice was issued was issued in October 2021 by the parent company NuVasive. The advice was monitoring of current cases and a hold on implantation until after a review of process. At the National Orthopaedic Hospital Cappagh we elected to remove all implanted nails and assess the nail integrity and physiological changes associated with implantation.
Materials & Methods
All patients in who a retained Precice nail at the time of the field safety notice were identified. Patients and families were contacted to explain the issued safety notice from the company and explain that we would be scheduling them for nail removal. This was part of our standard care but we prioritised this group on our waiting list. Consent was obtained for nail removal but also for histological assessment of canal scrapings, blood ion level analysis and independent assessment of the retrieved nail by our academic collaborators at University College Dublin. Ion levels were then repeated at an interval post removal with consent.
Results
We identified 7 Precice nails in 5 patients still implanted. All patients had consolidated after lengthening and were ready for nail removal. Elevated Titanium blood ion levels were identified at the time of retrieval. Histological abnormalities consistent with metalosis were identified. In all cases the nail was grossly intact and examination of the motor showed no evidence of wear or failure. Follow up ion levels obtained post retrieval showed persistent elevation.
Conclusions
Our retrieval audit shows persistent elevation of Titanium ion levels and abnormal histology despite apparent nail integrity. These findings require further evaluation in a larger retrieval series to determine if there is a high incidence of this phenomenon and if ion levels have a clinical effect.
