Obesity does not affect the success and outcomes of degenerative scoliosis correction surgery

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A new study published in the journal Spine has suggested that patient obesity has no impact on the correction, comorbidities, or complication rates associated with degenerative scoliosis correction surgery.

Lingjie Fu, of Sonoran Spine Center in Phoenix, USA, and colleagues conducted a retrospective cohort analysis of prospectively collected data with a view to determining whether an association exists between body mass and surgical outcomes in patients with degenerative scoliosis after long instrumented spinal arthrodesis (≥ four discs). The authors write: “Obesity is thought to be associated with increased surgical complications and inferior clinical outcomes in adults. There are no studies analysing the effect of obesity on surgical outcomes in patients with degenerative scoliosis after long instrumented spinal arthrodesis.”

Fu and colleagues note that “as the number of obese and overweight adults in the USA continues to increase, it is crucial to elucidate the effect of obesity on the surgical outcomes of patients with degenerative scoliosis.” As the first study to investigate the effect of body mass index (BMI) on clinical outcomes in degenerative scoliosis, the study holds additional value.

Eighty-four consecutive patients with degenerative scoliosis (69 females and 15 males with a mean age of 69) with a minimum follow-up of two years were included in this study. Patients were divided into three groups according to BMI: obese (BMI ≥ 30 kg/m2, n = 19), overweight (BMI = 25–29.9 kg/m2, n = 35), and normal weight (BMI < 25 kg/m2, n = 30). Radiographical measures, Oswestry Disability Index, visual analogue scale score, as well as comorbidities and complications were reviewed and analysed for all patients preoperatively and at one and two-year follow-ups.

Compared with the normal weight group, no significant differences in surgical methods, comorbidities, complication rates, curve correction, or radiographical measures were found in the obese and overweight groups, except for a greater preoperative lumbar lordosis in the overweight group (average of −40.3 degrees vs −26.0 degrees p<0.05). At two-year follow-up, Oswestry Disability Index and visual analogue scale scores improved significantly in all groups compared with preoperatively (p<0.01). The changes of Oswestry Disability Index and visual analogue scale scores from preoperatively to final follow-up were similar in the 3 groups (p>0.05). Fu et al comment that these results show that “obese and overweight patients benefit just as much as normal weight patients from having their curve corrected.” Complication rates were also “not significantly different among the three groups.”

Postoperative radiological outcomes also supported these results. According to the authors: “In the obese BMI group the percent correction (74%) was not significantly different from that of the overweight group (60%) or the normal weight group (62%). Furthermore, all coronal and sagittal radiographic parameters were statistically similar between the three groups at one and two-year follow-ups.”

Fu et al conclude by stating that “obesity did not affect the amount of deformity correction and did not increase comorbidities and postoperative complication rates.” Though they suggest that “the role of BMI on clinical outcomes in spine surgery remains controversial,” the results of this study indicate that there was no association between body mass and surgical outcomes in patients with degenerative scoliosis and that obese and overweight patients benefited from surgery just as much as normal weight patients at two-year follow-up.