Optimal correction of sagittal alignment and improving a patient’s functional capacity can significantly influence postoperative frailty resolution, according to a recent study by Peter Passias (NY Spine Institute, New York, USA) and colleagues. According to the authors, the CD-FI is an important tool in stratifying preoperative deformity patients and these findings quantified the improvement in postoperative frailty for cervical deformity frailty index (CD-FI) patients undergoing intervention. The results of this study were presented recently by co-author Edem Abotsi (NY Spine Institute) at the 19th Annual Conference of the International Society for the Advancement of Spinal Surgery (ISASS; 3–5 April 2019, Anaheim, USA).
The investigators report a correlation of improvement in radiographic and frailty component variables one-year post-surgical intervention. More specifically, they found that frailty decreased at one year along with a significant change in 13/40 (33%) CD-FI variables and that an improvement in ability to read, and feeling tired or exhausted correlated the most with improvement in frailty.
Furthermore, they write that average frailty decreased from 0.44 (“severely frail” status) to 0.25 (“frail” status) one-year post-surgery. Additionally, of the 40 variables included in the index, 20/40 (50%) improved at one-year, while 13/40 significantly improved. They note that the majority of the frailty drivers were patient-reported outcomes that measured improved functional status.
The authors begin by outlining that cervical deformity is a potentially severely debilitating condition that encompasses a wide range of etiologies, including spondylosis, inflammatory arthropathy, trauma, infection, iatrogenic, neoplastic, congenital, and neuromuscular pathologies. As a result, they identify that identification and stratification of patients at risk of complications is vital.
The investigators mention that Miller et al recently developed a novel adult CD-FI which correlated increased patient frailty with longer hospital stays, higher complication rates, and an increased risk of non-home discharge. According to Passias and colleagues, there are a few limitations of this index which prompted their current study. They mention in particular that it requires a total of 40 health variables to calculate and that it is unknown which of the variables have the greatest potential for change or are the primary drivers of postoperative change in frailty.
The objective of the present study was to determine the impact of corrective surgery on the CD-FI. They investigators further aimed to identify the drivers of postoperative frailty score and to determine which variables were modifiable and non-modifiable in response to surgical intervention.
Passias and colleagues describe the study as a retrospective review of a prospective, multicentre database of cervical deformity patients enrolled from 2013–2018. Those patients with complete baseline and one-year frailty scores were included in the study, while the exclusion criteria were defined as spinal deformity of neuromuscular etiology, and the presence of an active infection or malignancy.
The authors define cervical kyphosis as C2–C7 >10 degrees, cervical scoliosis as a Coronal Cobb angle >10 degrees, and a C2–C7 sagittal vertical axis of >4cm. Thoracic slope-cervical lordosis mismatch (TS–CL >10 degrees, chin-brow vertical angle C8VA) was defined as >25 degrees.
The surgical data that was collected for the study included the number of levels fused, the surgical approach, decompression type (discectomy, foraminectomy, corpectomy, or laminectomy), and the osteotomy type (incomplete/complete facet, Smith-Petersen osteotomy, and opening/closing wedge).
The investigators measured a number of global alignment parameters, including the sagittal vertical axis, regional spinopelvic parameters, such as pelvic incidence, lumbar lordosis, pelvic tilt, and the difference between pelvic incidence and lumbar lordosis. The final measurements related to regional and cervical alignment and included pelvic cervical kyphosis (C2–C7 angle >10 degrees, T1 slope angle subtended by superior T1 endplate and the horizontal), C2–C7 cervical lordosis (CL), T1 slope minus cervical lordosis (TS–CL), and C2–C7 sagittal vertical axis.