True lambdoid craniosynostosis: long-term results of surgical and conservative therapy.

BACKGROUND: True lambdoid synostosis is a rare malformation. Few clinical reports have examined the efficacy of conservative or surgical management in the care of these patients.
METHODS: All patients with a diagnosis of true lambdoid synostosis treated by the senior author (S.P.B.) at The Children's Hospital of Philadelphia between 1990 and 2005 were included in the study. Both qualitative and quantitative assessments of craniofacial growth were performed following either conservative or surgical management. Qualitative assessments were made based on preoperative and postoperative photographs, computed tomographic scans, and a review of patient charts. A quantitative assessment of ear position was performed using craniometric analysis and the appropriate statistical tests.
RESULTS: The study included nine patients--six who underwent surgical intervention and three who did not undergo transcranial surgery to date. The authors' analysis of patient data revealed a predictable craniofacial dysmorphism manifest as occipital flattening, an ipsilateral occipitomastoid bulge, and a pronounced hemifacial deficiency. Generally, these malformations improved following operative management. A quantitative analysis of preoperative and postoperative ear position displayed no statistically significant vertical or anteroposterior displacement. In one untreated patient, true lambdoid synostosis resulted in persistent severe asymmetry of the cranial vault and facial skeleton.
CONCLUSIONS: True lambdoid synostosis, if left untreated, results in pronounced craniofacial asymmetry. Although a diversity of clinical presentations exists, diagnostic features include occipital flattening, an ipsilateral occipitomastoid bulge, and a contralateral hemifacial deficiency. Posterior vault switch cranioplasty is an effective treatment for true lambdoid synostosis when performed in the first year of life.