Combined technique of titanium telescopic rods and external fixation in osteogenesis imperfecta patients: First 12...

The major limitation of any intramedullary telescopic system is rotational and longitudinal instability. The combination of telescopic system with an external fixator in patients with osteogenesis imperfecta (OI) demonstrated advantages of stability, early weight-bearing and rehabilitation. This study aimed to examine the outcomes of deformity correction by combined technique uniting titanium telescopic rod and reduced Ilizarov frame in children with types III or IV of OI with a minimum 1-year follow-up.

The study included 12 children with OI who underwent femoral deformity correction (20 segments) or tibial deformity correction (4 segments) by combined technique. The children ranged in age between 2 years and 3 months and 12 years and 4 months (mean: 8.9 ± 2.02 years) at the time of the rodding. Parameters of surgery, clinical examination data, data of 3D gait analysis were assessed in the study.

External fixation lasted 35.8 ± 13.2 days in average. Neither loss of threaded fixation in the distal femoral and tibial epiphyses and apophysis of the greater trochanter nor migration of the rod into the knee and ankle joints were observed in follow-up. No secondary rotational or longitudinal bone displacement was noted. Telescoping gain related to spontaneous growth assessed at one-year follow-up control was 13.7 mm in the tibia and 15.9 mm in the femur. There were no deep infection or neurologic complications. The alignment measured by radio anatomical reference angles was maintained throughout the follow-up period.Gait abnormalities in postoperative period were caused by bulk and weight of EF: external hip rotation, slight external angle of foot progression, increased stride width and increased hip abduction angle. The second feature was reduced ROM in sagittal plane at all levels associated with significantly reduced ankle plantarflexion, hip and knee joint moments in comparison to kinetics of limb without EF. These abnormalities resolved by the one-year assessment.

The combination of titanium telescopic rod with reduced external fixation is reliable advantage in reconstructive orthopaedic surgery for OI children. Reduced external fixation allows to overcome inconveniencies of longitudinal and rotational instability of telescopic systems. Children were able to walk with weight-bearing since early postoperative period because of external fixation. Gait temporary changes were influenced by external device size and by strategy to reduce pin site pain.