Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Ex Input:
Context: Pedicle subtraction osteotomy (PSO) is one of the surgical options for treating alignment disorders of the fused spine (due to post-surgical fusion or related to arthritis). It enables satisfactory sagittal realignment and improved function due to economic sagittal balance. The aim of this study was to analyze clinical and radiological results of PSO after a minimum follow-up of 2years and demonstrate the benefit of sub-group analysis as a function of pelvic incidence (PI).', 'A descriptive prospective single center study of 63 patients presenting with spinal global malalignment who underwent correction by PSO. Function was assessed by the Oswestry disability index (ODI), a visual analog scale of lumbar pain (VAS) and a SF-36 questionnaire. Radiographic analyses of pre- and post-operative pelvic-spinal parameters were performed on X-rays obtained by EOS(®️) imaging after 3D modeling. Global analysis and analysis of sub-groups as a function of pelvic incidence were performed and the full balance integrated index (FBI) was calculated.', 'this series showed a marked clinical improvement and significant progress of functional scores. Global post-operative radiological analysis showed a significant improvement in all pelvic and spinal parameters. The mean correction obtained after PSO was 31.78.4, hence global improvement of lumbar lordosis of 22. The sagittal vertical angle (SVA) decreased from +9cm before surgery to +4.3cm after surgery. Sub-group analysis demonstrated greater improvement in pelvic tilt, sacral slope and spinal parameters of patients with a small or moderate pelvic incidence; all had an FBI index<10. Most of the pelvic and spinal parameters of patients with a large pelvic incidence were insufficiently corrected and they had an FBI index>10
Answer: PSO is a surgical procedure enabling correction of multiplane rigid spinal deformities that require major sagittal correction. It was seen to be highly effective in patients with a small or moderate pelvic incidence (PI<60) but was sometimes less effective in patients with large pelvic incidence due to insufficient lordosis correction. Clinical results were highly correlated with the value of the FBI index.

Ex Output:
Are clinical and radiological outcomes of lumbar posterior subtraction osteotomies correlated to pelvic incidence and FBI index : Prospective series of 63 cases?

Ex Input:
Context: Mast cells have been associated with obliterative bronchiolitis (OB) in human pulmonary allografts, although their role in the development of OB remains unknown.', 'In this study, we evaluated the role of mast cells in pulmonary allograft rejection using an orthotopic rat pulmonary allograft model that utilizes chronic aspiration of gastric fluid to reliably obtain OB. Pulmonary allograft recipients (n = 35) received chronic aspiration of gastric fluid with (n = 10) and without (n = 16) treatment with a mast cell membrane stabilizer, cromolyn sodium, or chronic aspiration with normal saline (n = 9) as a control.', 'The acute graft injury associated with long ischemic time in the model (6 hours total ischemic time; typical acute graft injury rate ~30%) was apparently blocked by cromolyn, because peri-operative mortality associated with the acute graft injury was not observed in any of the animals receiving cromolyn (p = 0.045). Further, the rats receiving cromolyn developed significantly fewer OB lesions than those treated with gastric fluid alone (p < 0.001), with a mean reduction of 46% of the airways affected.
Answer: These findings provide impetus for further studies aimed at elucidating the effects of cromolyn and the role of mast cells in pulmonary allotransplantation.

Ex Output:
Does cromolyn ameliorate acute and chronic injury in a rat lung transplant model?

Ex Input:
Context: Objective analysis of surgical skill is necessary. A novel method of assessment using simple error analysis in synthetic models is examined for construct validity.', 'Two examination protocols were devised using synthetic models. These contained either a purpose made error or were representative of good surgical practice. Protocol one contained models of skin closure and minor operations. Protocol two in addition more complex procedures. Face validity was established by the approval of senior surgeons. Junior surgeons were recruited to undertake the assessment. A p value of less than 0.05 was deemed to be significant.', 'Eighty-nine surgeons were recruited. Both protocol one and two were able to discriminate between groups at statistically significant levels.
Answer: Construct validity has been established by showing that error analysis is able to distinguish surgeons with varying levels of experience.

Ex Output:
Is the surgical error examination a novel method for objective technical knowledge assessment?