Treatment of Unilateral Lambdoid Synostosis Using Cranium Distraction Osteogenesis With Z-shaped Osteotomy.

Purpose: We studied the effect of cranium distraction osteogenesis using Z-shaped osteotomy to treat unilateral lambdoid synostosis.

Methods: Simulating the occipital, parietal, and temporal bones as a hemisphere, we designed a lambdoid suture that connected parallel osteotomy and sagittal sutures or extended to fossa cranii posterioras much like the parallel lines connect the upper and lower aspects of the letter Z. Two to 3 distraction devices were then installed after the Z-shaped osteotomy suture. From the second day postoperation, distraction at 0.6 mm twice a day up to 2 to 3 cm. Finally, we removed the distraction devices 3 months later.

Results: In total, 6 cases of unilateral lambdoid synostosis were performed and over 24 months mean follow-up (5-36 months), all patients were satisfied with cosmetic and functional outcomes. No complications, including fixed screw displacement, penetration of the cranium or dura matter or retraction of distraction devices occurred.

Conclusions: This procedure not only raises cranial height and extends it upward but also singularizes the occipital carina by prolonging it in a downward direction to form a occipitalia. The separated cranium is not easy to retract after fixation for 3 months so management of unilateral lambdoid synostosis with cranium distraction osteogenesis with a Z-shaped osteotomy is effective.