Clinical effect of kickstand rod in posterior throacolumbar orthopedic fusion surgery in treating patients with spinal scoliosis accompanied by severe coronal imbalance and pelvic obliquity

English Keywords:Scoliosis  Pelvic obliquity  Coronal imbalance  Kickstand rod  Pelvic fixation

English Abstract:

  【Abstract】 Objectives: To evaluate the correction of kickstand rod(KR) in posterior thoracolumbar fusion surgery for the treatment of scoliosis patients with severe coronal imbalance(CI) and pelvic obliquity(PO). Methods: From January 2019 to December 2020, a consecutive cohort of 45 scoliosis patients with CI and PO undergoing posterior thoracolumbar(spino-pelvic) fusion in our hospital were retrospectively analyzed, including 6 males and 39 females, aged 51.2±17.5(12-73) years, and followed up for 16.4±5.3 months(11-26 months). According to pelvic fixation method, the patients were divided into KR group of 20 cases fixed with KR technique and non-KR group of 25 cases fixed with S2 alar-iliac(S2AI) screw and iliac sacral screw(ISS). On the full spine anteroposterior and lateral radiographs before operation, at postoperative 7d and final follow-up, the coronal balance distance(CBD), pelvic obliquity angle(POA), coronal Cobb angle, lumbosacral fractional curve(LFC), and pelvic incidence(PI) were measured. The correction rates of spinopelvic parameters and the correction loss rates at the final follow-up were compared between the two groups. The complications after operation and during follow-up were collected. Results: The Cobb angle, POA, CBD, LFC and PI before operation were not statistically different from each other between the two groups(P>0.05), and those at postoperative 7d of both groups were statistically different from those before operation(P<0.05). In KR group, the Cobb angle, POA, CBD, LFC, and PI at final follow-up were not significantly different from those at postoperative 7d(P>0.05). In non-KR group, while the POA at final follow-up significantly decreased from that at postoperative 7d(P<0.05). The correction rates of POA and CBD in KR group and non-KR group were(66.9±13.4)% vs (44.2±23.4)% and (58.5±20.9)% vs (42.9±20.9)% respectively(P＜0.05). The differences of other imaging parameters between the two groups were not with statistical significance(P>0.05). During follow-up period, 1 patient in KR group developed rod breakage and 3 patients in non-KR group developed CI. The incidence of complications did not show any statistical difference between the two groups(χ2=0.672, P=0.412). Conclusions: Compared with traditional spino-pelvic fixation technique, KR based posterior spino-pelvic fusion surgery could achieve comparable correction and maintain coronal balance and pelvic level in scoliosis patients combined with severe coronal imbalance and pelvic obliquity.