Postoperative Evolution of Sagittal Parameters Over Time Does Not Differ by Upper Instrumented Vertebra

Abstract

Study Design. Retrospective cohort study.Objectives. The aim of this study was to examine sagittal alignment over time in adult spinal deformity (ASD) and to understand whether these changes vary by choice of upper instrumented vertebra (UIV). Summary of Background Data. Recent ASD literature has focused on specific alignment goals. Less is known about how sagittal parameters evolve over time after surgical correction and whether these changes differ by choice of UIV. Methods. This was a retrospective review of ASD patients from a single institution. Routine 36 00 sagittal x-rays were obtained preoperatively, before hospital discharge, and at 6 months, 1 year, and 2 years and sagittal parameters were measured. Patients with UIV T6 and above were classified as upper thoracic (UT) and T7 and below as lower thoracic (LT). Results. A total of 102 patients with mean age 66.0 years (AE7.7) were included in the analysis (49 UT, 53 LT). All sagittal and coronal alignment parameters demonstrated significant improvement from preoperatively to any postoperative time point. Although multiple parameters maintained correction over time, others (TK, TPA, and PT) demonstrated significant increase from discharge to 2 years postoperatively, with changes occurring relatively early after surgery, whereas overall global alignment was maintained. Both UT/LT groups demonstrated significantly greater TK from preoperatively to discharge to 6 months (P < 0.05), stabilizing at that time point out to 2 years, whereas TLK preferentially increased in the LT group. There was significant improvement in sagittal vertical axis after surgery, which was maintained out to 2years of follow-up (P > 0.05). Conclusions. Our data suggest that although several key parameters are maintained over time out to 2years postoperatively, TK tends to worsen over time for all patients, whereas TLK preferentially increases in the LT group. Nevertheless, despite these trends, compensatory changes are seen in PT such that global alignment is relatively maintained.

Risk Factors of Postoperative Coronal Balance Transition in Degenerative Lumbar Scoliosis

“…Nevertheless, literature regarding the regression of postoperative CIB was limited. Recent articles [26][27][28] reported a progressive loss of sagittal balance after degenerative scoliosis has been corrected, indicating that most elderly patients have compensatory ability and alteration of postoperative sagittal balance. Thus, when monitoring the postoperative CB, particularly for patients with immediate balance after surgery, it is important to pay attention to the dynamic change process during the follow-up period.…”

Revision Free Loss of Sagittal Correction > 3 Years After Adult Spinal Deformity Surgery

“…The mean age at the time of the surgery was 63. 5 9.6 years, 80.3% were female, the mean Body Mass Index was 27.9 kg/m 2 5.8, the median Charlson Comorbidity Index was 2 [interquartile range (IQR: 1-3)] and 56.9% had a history of previous spine surgery (Table 1). Preoperative PROs demonstrated severe disability with a mean Oswestry Disability Index of 45.9 15.9, mean Short Form 36 Physical Component Score of 30.2 8.9, and mean total SRS score of 2.71 0.61 (Table 1).…”

“…The relationship between sagittal alignment, patient-reported outcomes (PROs), and mechanical complications within adult spinal deformity (ASD) is well known 1–4 . However, several authors have shown that many patients experience worsening sagittal alignment after their initial correction 5 . Given the relationship between alignment and PROs, it would follow that the long-term maintenance of the correction is critical to ensuring satisfactory long-term outcomes.…”

“…However, new series have demonstrated that changes also occur in the instrumented portion of the spine. 5 It is unknown whether changes occur in the instrumented lumbar spine. Furthermore, past studies have not isolated patients with mechanical complications from those with maintained constructs.…”

“…[1][2][3][4] However, several authors have shown that many patients experience worsening sagittal alignment after their initial correction. 5 Given the relationship between alignment and PROs, it would follow that the long-term maintenance of the correction is critical to ensuring satisfactory long-term outcomes.…”