To evaluate the effect of three-dimensional Z-shaped osteotomy with cranium distraction osteogenesis for unilateral lambdoid synostosis.

Imaging the skull as a cuboid, we designed the affected lambdoid suture as the middle line of letter Z, the osteotomy line paralleling to the sagittal suture or extending downward posterior cranial fossa as the two horizontal lines of Z to obtain the three-dimensional Z-shaped osteotomy lines. Two or three distraction devices were installed after removing the cranial bone at the premature fused suture with a width of 2.0-2.5 cm. Since the 5th day after operation, distraction was performed at the rate of 0.6 mm each day, twice a day, until the distraction distance reached 2.0-4.5 cm. Finally, we removed the distractors after fixation for three months.

Eleven cases of unilateral lambdoid synostosis were treated successfully. No infection or bleeding happened except for one case with distractor entrance scalp infection. No complications, including the fixed screws displacement, penetrating the cranium and the dura mater or distraction devices retracting, occurred. During a mean follow-up period of 24 months (5 to 36 months), all patients were satisfied with the cosmetic and functional result.

Three-dimensional Z-shaped osteotomy with cranium distraction osteogenesis can not only extend upward to raise the cranial height, but also lengthen backward to singularize the occipital carina, forming a well-pleasing occipitalia. Z shape stabilizes the whole plate, making the separated cranial bones not easy to retract. Therefore, using this procedure is effective and mini-invasive, and especially suitable for young infant.

Lambdoid suture; Craniosynostosis; Z-shape; Osteotomy; Osteogenesis, distraction