Correlation of Acetabular Anteversion and Thoracic Kyphosis Postoperatively with Proximal Junctional Failure in Adult Spinal Deformity Fused to Pelvis

Abstract

Objectives: To investigate whether the immediate thoracic kyphosis (TK) and acetabular anteversion (AA) postoperatively are correlated with proximal junctional failure (PJF) in adult spinal deformity (ASD) patients underwent surgical treatment.Methods: This is a retrospective study. Following institutional ethics approval, a total of 57 patients (49 Female, eight Male) with ASD underwent surgery fused to sacroiliac bone (S1, S2, or ilium) from March 2014 to January 2019 were included. All of those patients were followed up for at least 2 years. Demographic, radiographic and surgical data were recorded. The maximum range of flexion motion (F-ROM) and extension motion (E-ROM) actively of hip joints was measured and recorded at pre-and postoperation. The sum of F-ROM and E-ROM was defined as the range of hip motion (H-ROM). Receiver operating characteristic (ROC) curve analysis was used to obtain the cut off value of parameters for PJF. A Kaplan-Meier curve and log-rank test were used to analyze the differences in PJF-free survival.Results: In all, 14 patients developed PJF during follow-up. Comparisons between patients with and without PJF showed significant differences in immediate TK (P < 0.001) and AA (P = 0.027) postoperatively. ROC curve analysis determined an optimal threshold of 13 for immediate AA postoperatively (sensitivity = 74.3%, specificity = 85.7%, area under the ROC curve [AUC] = 0.806, 95% CI [0.686-0.926]). Nineteen patients with post-AA ≤13 were assigned into the observational group, and 38 patients with post-AA >13 were being as the control group. Patients in the observational group had smaller H-ROM (P = 0.016) and F-ROM (P < 0.001), but much larger E-ROM (P < 0.001). There were 10 patients showing PJF in the observational group and four in the control group (10/9 vs 4/34, P < 0.001). PJF-free survival time significantly decreased in the observational group (P = 0.001, log-rank test). Furthermore, patients in the observational group had much larger TK (post-TK, P = 0.015). The optimal threshold for post-TK (sensitivity = 85.7%, specificity = 76.7%; AUC = 0.823, 95% CI [0.672-0.974]) was 28.1 after the ROC curve was analyzed. In the observational group, those patients with post-TK ≥28.1 had significantly higher incidence of PJF (9/2 vs 1/7, P < 0.001) than those with post-TK < 28.1 . Moreover, PJF-free survival time in those patients significantly decreased (P = 0.001, log-rank test).Conclusions: ASD patients with acetabular anteversion of ≤13 at early postoperation may suffer significantly restricted hip motion and much higher incidence of PJF during follow-up, moreover, in those patients, postoperative TK ≥28.1 would be a significant risk factor for PJF developing.

Association of spinopelvic index with proximal junctional failure developing in adult spinal deformity after surgical treatment: an observational study

“…We subdivided all patients into two groups by 28° of the immediate TK postoperatively (post-TK) suggested by professor Zhang et al [15]. For those patients in the observational group, there was no difference in PJFfree survival time between those with post-TK ≥ 28° and those with post-TK < 28° (P = 0.1, log-rank test) (Fig.…”

“…According to those results reported in recent studies [20,21], full-body balance describes the optimal alignment of the spine in the sagittal plane, resulting from the interaction between the spine and lower limbs, via the pelvis. Moreover, Zhang et al [15] suggested that the pathological hip joints would increase the incidence of proximal junctional failure (PJF) significantly in adult spinal deformity (ASD) patients underwent correction surgery. As a result of, we concluded that the match between spine and hip joints may correlate significantly to the quality of life of ASD patients who have undergone deformity correction surgeries.…”

“…However, Zhang et al [15] suggested that the smaller acetabular anteversion postoperatively would result in PJF developing, which may be accelerated by the larger TK postoperatively. After stratifying all patients by the optimal threshold of 28° for post-TK proposed by professor Zhang et al [15], post-TK ≥ 28° may decrease significantly the PJF-free survival time, especially for those with SPI ≤ 0.82 (Figs. 4 and 6).…”

“…In addition, previous studies reported that much larger global spinal alignment (thoracic kyphosis + lumbar lordosis + PI) was risk factor for PJK [3,14]. However, Zhang et al [15] suggested that the associations of thoracic kyphosis (TK) postoperatively with PJF developing may be based on the condition of hip joints. Therefore, we investigated whether the larger TK postoperatively would deteriorate the SPI, which may accelerate PJF developing in those ASD patients after correction surgery?…”

How does the correction in lumbar lordosis affect the spinopelvic realignments in degenerative lumbar scoliosis underwent scoliosis surgery?

“…Furthermore, previous studies have illustrated that the surgical procedure of thoracolumbar fusion with instrumentations can restore the spinopelvic alignments effectively in DLS [ 4 , 10 , 11 ]. However, the abnormal correction in LL may result in abnormal spinopelvic alignments, which would increase the incidence of mechanism complications, and deteriorate the QoL accordingly [ 12 – 17 ] because of the mismatch among the spine, pelvis and lower extremities [ 12 , 18 ].…”