From the University of Washington School of Medicine.
Division of Plastic Surgery, Department of Surgery.
Plast Reconstr Surg. 2023 Jul 1;152(1):155-165. doi: 10.1097/PRS.0000000000010228. Epub 2023 Jan 24.
The purpose of this study was to quantify change in cranial morphology in patients with nonsyndromic unilateral lambdoid craniosynostosis (ULC) from presentation (t0), after open posterior switch-cranioplasty (t1), and at 2-year follow-up (t2).
Volumetric, linear, and angular analysis were performed on computed tomographic scans at the three time points and against normal control subjects. Significance was set at P < 0.05.
Twenty-two patients were included. ULC cranial vault asymmetry index was higher than in control subjects before surgery (6.22 ± 3.55) but decreased after surgery (3.00 ± 2.53) to become comparable with the normal asymmetry range present in the controls. After surgery, both diagonals increased, but more on the fused side. In the 2 years after surgery, both diagonals in patients with ULC grew proportionately, but the fused diagonal remained slightly shorter than the patent side. Total cranial volume was higher in patients with ULC than in control subjects after surgery but became comparable at t2. Cranial base angulation improved by t2 but did not approach normal, and ear position remained unchanged. The facial twist was higher than in controls at t0 and t1 but was comparable at t2. Coronal asymmetry improved with surgery but remained undercorrected at t2, with the greatest residual asymmetry at opisthion.
Open-switch cranioplasty normalizes cranial vault asymmetry index by increasing the fused cranial diagonal more than the patent side and is stable at 2 years. Skull base twist does not normalize, but facial twist approaches normal. Technique improvement should focus on residual coronal asymmetry present at opisthion.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.
本研究旨在定量分析非综合征性单侧矢状缝早闭（ULC）患者从初诊（t0）、行开放式后路切换颅骨成形术后（t1）以及 2 年随访（t2）时颅形态的变化。
在三个时间点对 CT 扫描进行容积、线性和角度分析，并与正常对照组进行比较。设定显著性水平为 P < 0.05。
共纳入 22 例患者。ULC 颅顶不对称指数高于术前对照组（6.22 ± 3.55），但术后降低（3.00 ± 2.53）至与对照组正常不对称范围相当。术后，双侧对角线均增加，但融合侧增加更多。术后 2 年内，ULC 患者双侧对角线均按比例生长，但融合对角线仍略短于未融合侧。术后患者总颅容量高于对照组，但 t2 时与对照组相当。颅底角度在 t2 时改善，但未接近正常，耳位不变。面部扭转在 t0 和 t1 时高于对照组，但在 t2 时与对照组相当。冠状面不对称性随着手术改善，但在 t2 时仍未完全矫正，最大残余不对称性位于枕骨后。
开放式切换颅骨成形术通过增加融合颅骨对角线的长度超过未融合侧来使颅顶不对称指数正常化，且在 2 年内保持稳定。颅底扭转未恢复正常，但面部扭转接近正常。技术改进应侧重于存在于枕骨后区的残余冠状面不对称。
临床问题/证据水平：治疗性，IV 级。
