Objective: To evaluate the feasibility of placement of S(2) alar iliac screw (S(2)AI) using free-hand technique for sacrapelvic fusion in lumbar degenerative scoliosis. Methods: Eighteen patients with Lumbar Degenerative Scoliosis treated by S(2)AI screw fixation at Department of Orthopedics, General Hospital of Southern Theater Command of People’s Liberation Army and Department of Orthopedics, 89th hospital of People’s Liberation Army from August 2014 to October 2018 were analyzed retrospectively. There were 5 males and 13 females, aged 63.2 years old (range:55 to 71 years old).Parameters of spine including: Cobb Angle, C(7) plumb line -center sacral vertical line (C(7)PL-CSVL), lumbar lordosis(LL), sagittal vertical axis(SVA), pelvic incidence(PI), pelvic tilt(PT), sacral slope (SS) and pI-LL were measured on the whole spine X-ray before operation and at final follow-up. Pelvic CT scan was performed postoperatively to assess the accuracy of S(2)AI placement. Oswestry disability Index (ODI) was also recorded. The data were compared by paired t test or Wilcoxon tests. Results: All patients were followed up for 23.7 months (range: 12~62 months).At the last follow up, Cobb Angle decreased from (32.28±4.97) °preoperative to (6.56±3.20) ° (t=41.142, P<0.01) and C(7)PL-CSVL deceased from (1.11±2.07) cm preoperative to (0.18±1.08) cm (t=41.142, P=0.06) .LL improved from (-22.39±13.07) °preoperative to (-36.39±4.29) ° (t=4.470, P<0.01) , PI-LL decreased from (26.83±14.83)°preoperative to (13.72±8.3)° (t=4.396, P<0.01) , PT decreased from (27.94±4.26) °to (23.39±6.08) ° (t=2.680, P=0.02) , and SS increased from (22.22±6.36) °to (26.28±7.24) ° (t=-2.178, P=0.04) .SVA decreased from (6.54±4.51) cm preoperative to (2.62±1.29) cm (t=3.052, P=0.01) .ODI decreased from 0.58(0.40) (M(Q(R))) to 0.18 (0.15) (Z=-4.567, P<0.01) .No complications such as nerve and blood vessel injury occurred during the operation. A total of 32 S(2)AI screws were placed, 3 screws were placed with mild to moderate cortical breaches, 2 were perforated the pelvis ventrally, 1 was perforated posteriorly, with no clinically notable neurovascular or visceral complications. Eight patients finished the SRS-22 questionnaire, with mean score of 4.4 in terms of satisfaction with management. Conclusions: Free-hand technique of S(2)AI screw placement for sacrapelvic fusion in degenerative lumbar scoliosis is safe and feasible.S(2)AI fixation in DLS can provide great correction of deformity, maintain the stability of lumbo-pelvic area and improve the clinical symptoms.

目的： 探讨徒手经第2骶骨翼骶髂螺钉（S(2)AI）植入技术应用于退变性腰椎侧凸腰骶骨盆固定融合术的可行性。 方法： 回顾性分析2014年8月至2018年10月南部战区总医院和解放军第八十九医院收治的采用徒手S(2)AI植入技术治疗的18例退变性腰椎侧凸患者的临床资料。其中男性5例，女性13例，年龄63.2岁（范围：55~71岁)。测量术前及末次随访时患者站立位脊柱全长正侧位X线片的相关参数，包括主弯侧凸Cobb角，冠状面躯干偏移（C(7)PL-CSVL)、腰椎前凸角（LL)、矢状面铅锤轴线（SVA)、骨盆投射角（PI)、骨盆倾斜角（PT)、S(1)骶骨倾斜角（SS）及脊柱-骨盆匹配度；术后行骨盆CT评估S(2)AI植入准确性，同时记录术前及末次随访时Oswestry功能障碍指数评估临床症状缓解情况并记录并发症情况。手术前后指标比较采用配对样本t检验或非参数Wilcoxon检验。 结果： 所有患者均获得随访，平均随访时间23.7个月（范围：12~62个月)。末次随访时，患者的腰椎侧凸Cobb角由术前的（32.28±4.97）°降至（6.56±3.20）°（t=41.142，P<0.01），C(7)PL-CSVL由术前的（1.11±2.07）cm降至（0.18±1.08）cm（t=41.142，P=0.06），LL由术前的（-22.39±13.07）°改善至（-36.39±4.29）°（t=4.470，P<0.01），脊柱-骨盆匹配度由术前的（26.83±14.83）°降至（13.72±8.3）°（t=4.396，P<0.01），PT由术前的（27.94±4.26）°降至（23.39±6.08）°（t=2.680，P=0.02），SS由术前的（22.22±6.36）°升至（26.28±7.24）°（t=-2.178，P=0.04），SVA由术前（6.54±4.51）cm降至（2.62±1.29）cm（t=3.052，P=0.01），矢状面失平衡明显改善。Oswestry功能障碍指数从术前0.58(0.40）分[M(Q(R))]降至0.18（0.15）分（Z=-4.567，P<0.01)，临床症状明显缓解。18例患者共植入S(2)AI螺钉32枚，术中未发生神经、血管损伤等并发症，术后3例患者CT检查见S(2)AI突破皮质，1例为2级（中度)，偏向腹侧；2例为1级（轻度），1例偏腹侧，1例偏背侧。8例患者末次随访时完成了SRS-22问卷，手术满意度平均4.4分。 结论： 徒手S(2)AI植入技术应用于退变性腰椎侧凸腰骶骨盆固定融合术能维持腰骶骨盆稳定性，临床效果满意。.