Incidence of Proximal Junctional Kyphosis With Pedicle Screws at Upper Instrumented Vertebrae in Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis

Abstract

<jats:sec><jats:title>Study Design:</jats:title><jats:p> Longitudinal cohort. </jats:p></jats:sec><jats:sec><jats:title>Objectives:</jats:title><jats:p> Posterior spinal fusion (PSF) using all-pedicle screw constructs has become the standard procedure in the treatment of adolescent idiopathic scoliosis (AIS). However, there have been several reports that all-pedicle screw constructs or the use of pedicle screws at the upper instrumented vertebrae (UIV) increases the incidence of proximal junctional kyphosis (PJK). We aimed to evaluate the impact of instrumentation type on the incidence of PJK following PSF for AIS. </jats:p></jats:sec><jats:sec><jats:title>Methods:</jats:title><jats:p> We performed a stratified random sampling from 3654 patients enrolled in a multicenter database of surgically treated AIS to obtain a representative sample from all Lenke types. Patients were then allocated into 3 groups based on the instrumentation type: all-pedicle screw (PS), hook at UIV with pedicle screws distally (HT), and hybrid constructs (HB). We measured proximal junctional angle (PJA) and defined PJK as PJA ≥ 10° and PJA progression of &gt;10° at the final follow-up. </jats:p></jats:sec><jats:sec><jats:title>Results:</jats:title><jats:p> Fifteen (4.3%) of 345 cases had PJK. PJK was significantly more common in PS (11%) compared with HB (1%) and HT (0%) ( P &lt; .001). PJK patients were similar to non-PJK patients regarding age, sex, curve type, UIV, and preoperative coronal Cobb angle. Thoracic kyphosis was significantly higher in the PJK group before surgery. Patients who developed PJK had a statistically significantly larger negative sagittal balance compared with the non-PJK group. </jats:p></jats:sec><jats:sec><jats:title>Conclusion:</jats:title><jats:p> The incidence of PJK was 4.3% and was more common in all-pedicle screw constructs. Using hooks at UIV might be a treatment strategy to limit PJK. </jats:p></jats:sec>

Postoperative proximal junctional kyphosis correlated with thoracic inlet angle in Lenke 5c adolescent idiopathic scoliosis patients following posterior surgery

“…The extended fusion group also had higher risk of PJK in this study. This may partially explain the higher incidence rate of PJK in the present study rather than the one in previous studies after selective TL/L fusion of Lenke 5C patients [ 3 , 4 , 23 ]. Hence, extended fusion should be carefully evaluated in patients with Lenke 5C AIS who have a TIA of > 71°.…”

“…These patients may have developed an immediate increase in TK after surgery, but the large TIA also meant that they needed a much larger GTK at the final follow-up. In Ogura’s study, the increased TK at final follow-up time was also risk factor of PJK [ 23 ]. The increasing TK and GTK immediately after surgery were not enough for these patients; the TK and GTK continued to increase during follow-up, leading to PJK at the final follow-up.…”

“…The importance of maintaining appropriate postoperative SVA was also found in patients with Lenke 5C AIS [ 3 ]. AIS patients with preoperative negative SVA may have higher risk of PJK [ 23 ]. However, the present study did not find a correlation between PJK and SVA or LL.…”

Sagittal Balance Parameters and Proximal Junctional Kyphosis in Adolescent Idiopathic Scoliosis

“…Therefore, 22 studies were analyzed in our meta-analysis. In our systematic review, we included a total of 3922 patients; all were under the age of 18 years and were operated on due to adolescent idiopathic scoliosis [1,4,5,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] (Figure 1). statistical heterogeneity (α = 0.05), the χ 2 test was employed, and I 2 statistics were used to quantitatively assess heterogeneity.…”

The application of finite element analysis to determine the optimal UIV of growing-rod treatment in early-onset scoliosis

“…It can provide a stronger control force and reduce the mechanical stress of the instrumentation. However, dual growing rods and pedicle screw fixation, the most stable and effective option, may be more likely to lead to PJK (Pan et al, 2018;Ogura et al, 2021). Clinical studies have shown that there are many factors associated with PJK, but the relationship between the position of pedicle screw fixation and PJK is still a controversial topic (Homans et al, 2020).…”