Statistical changes of lung morphology in patients with adolescent idiopathic scoliosis after spinal fusion surgery—a prospective nonrandomized study based on low-dose biplanar X-ray imaging

BACKGROUND: Adolescent idiopathic scoliosis (AIS) patients suffer from restrictive impairment of pulmonary function (PF) as a consequence of spinal and ribcage deformity. Statistic modelling of scoliotic geometry has been well-established based on low-dose biplanar X-ray device (EOS) imaging. However, the postoperative lung morphology change derived from EOS has not yet been studied adequately till now. METHODS: Twenty-five female AIS patients with severe right-sided major thoracic curve (aged 13–31 years; Cobb angle 45°–92°) underwent posterior spinal fusion (PSF) were prospectively recruited for standing EOS imaging at preoperative, postoperative, and 1-year follow-up (1Y-FU) stages. EOS-based lung morphology at frontal and lateral view was measured respectively to assess serial statistical changes in area and height. RESULTS: At frontal view, left lung area significantly increased postoperatively (104.7 vs. 125.1 cm(2); P0.05). At lateral view, the increase in left lung area was slight without statistically difference (median: 175.8, 178.4, 182.5 cm(2) at preoperative, postoperative, 1Y-FU stage, respectively; all P>0.05), while right lung area did not significantly change postoperatively (median: 209.9, 206.7, 212.4 cm(2) at preoperative, postoperative, 1Y-FU stage, respectively; all P>0.05). At both frontal and lateral view, left lung height significantly improved at both postoperative and 1Y-FU stage (all P0.05). CONCLUSIONS: EOS imaging demonstrates that left lung area in severe AIS may improve after PSF surgery. EOS may provide useful information about lung morphology change after PSF in severe AIS.