Case report: Atlantoaxial instability in a 4-year-old child treated with harms technique

A 4-year-old child with a chronic inflammatory syndrome and osteolytic lesions of unknown cause presented with C1ĝ€"C2 instability and myelopathy. She was treated successfully with posterior atlantoaxial screw arthrodesis with Harms technique. Atlantoaxial instability in children is rare and is usually treated with conventional wiring techniques or transarticular screw fixation (Magerl technique). The latter shows very high fusion rates, but it is technically demanding and has a potential risk of injury to the vertebral artery (VA). In addition, in some cases the procedure cannot be used because of anatomical unsuitability or the presence of fixed subluxation of C1 on C2. To overcome these limitations, Harms developed a technique of fixation with pedicle screws. The technique is easier to apply than transarticular screw fixation and lowers the risks of injury to the VA. Fusion rates are comparable. The authors used polyaxial-head screws and rods for posterior fixation of the atlantoaxial complex in a 4-year-old child. Successful posterior fusion of C1ĝ€"C2 and decompression of the myelum was achieved. Fixation of the atlantoaxial complex using the Harms technique is an efficient alternative to previously reported fusion techniques for the pediatric population.