Outcome of Locking Plate Fixation Adjunctive to Intramedullary Rodding in Osteogenesis Imperfecta Patients.

Background: An intramedullary rodding is the preferred fixation method in limb stabilization of OI patients. However, the intramedullary rod may not provide adequate fixation and rotational stability, especially in adolescents and adults. The incorporation of adjunctive plate fixation alongside intramedullary rodding has been introduced to enhance this stability, although its complications remain insufficiently understood. The goal of this study was to explore the outcomes of adjunctive plating in conjunction with intramedullary rodding for limb stabilization in OI patients, emphasizing the complications related to the plates during the healing phase and following plate removal.

Methods: This retrospective study examined 74 limb segments from 45 patients with OI who underwent intramedullary rodding and adjunctive plating from 2008 to 2022. Criteria for inclusion comprised surgical treatment followed by a minimum of 2 years of follow-up or complication before that time point. The need for adjunctive plating arose from inadequate fixation, rotational instability, and persistent cortical gaps with intramedullary rodding alone. Medical records and follow-up radiographs were reviewed to assess the healing of the target lesion and any complications.

Results: The study encompassed 30 males and 15 females, ranging in age from 4 to 38 years, with 51 femoral and 23 tibial segments receiving treatment. Union was successfully achieved in 63 cases (85.3%), with an average union time of 14.4 months. Plates were subsequently removed in 62 cases after an average duration of 18.0 months. Before union, 11 revision surgeries were performed in 4 peri-implant fractures, 1 screw pull-out, and 6 failure of union. One sustained peri-implant fracture after the union. Following the removal of plates, complications included 10 refractures at screw sites, 3 progressive angulations at the previously targeted lesions, and 1 osteomyelitis. Kaplan-Meier analysis revealed that half of the refractures occurred within 1.8 years postplate removal. The overall complication showed borderline significance (P=0.056) among age groups. All the plate-related complications occurred at the diaphyseal, unicortical screws.

Conclusions: Plate fixation, when used as an adjunct to intramedullary rodding, effectively stabilizes limbs in OI patients when intramedullary rods alone are inadequate. Nevertheless, given the significant risks associated with plate-related complications, adjunctive plating should be employed selectively only in instances where the union is unlikely to be achieved with intramedullary rodding alone.

Level of evidence: Level IV-case series.