Baba Kazuyoshi, Takahashi Kohei, Hashimoto Ko, Onoki Takahiro, Aki Takashi, Fujita Ryo, Ishikawa Keisuke, Aizawa Toshimi
Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
J Spine Surg. 2024 Jun 21;10(2):244-254. doi: 10.21037/jss-23-145. Epub 2024 Jun 14.
In upright standing, spinopelvic mismatch is compensated by hip extension. However, few studies have investigated the reciprocal relationship between the sagittal alignment of the hip joints and spinopelvic mismatch during upright standing in humans. Our study aims to investigate (I) the relationship between spinopelvic mismatch and hip extension and (II) whether insufficient hip extension against spinopelvic mismatch, i.e., pelvic incidence (PI)-lumbar lordosis (LL), affects trunk inclination in upright standing.
This study was a retrospective cross-sectional study. We included 398 consecutive female patients treated for osteoporosis at our outpatient department between November 2017 and June 2022. Patients with any of the following were excluded from the study: (I) those whose plain whole-spine radiographs did not cover the femurs, (II) those with fractures in the vertebrae or lower extremities, (III) those with a history of surgery of the spine or of the lower extremities, (IV) those with scoliosis with a Cobb angle ≥10° in the anteroposterior radiograph, and (V) those with transitional vertebrae. Sixty-two patients were divided into normal and malalignment groups based on their sagittal spinal alignment. The patients underwent plain whole-spine radiography as a routine examination. A linear approximation between the pelvic femoral angle (PFA), representing hip extension, and PI-LL was obtained in both groups. The optimal PFA of each patient was obtained by substituting the PI-LL into the linear approximation of the normal group. The difference between the optimal and measured PFA was defined as the ΔPFA for each patient. The correlation between the ΔPFA and sagittal vertical axis (SVA) was evaluated in both groups.
The PFA and PI-LL were correlated in both groups. The malalignment group had a significantly greater ΔPFA than the normal group. ΔPFA was correlated with SVA only in the malalignment group.
The magnitude of the ΔPFA indicated insufficient hip extension to compensate for the spinopelvic mismatch during upright standing.
在直立站立时，脊柱骨盆失配通过髋关节伸展来代偿。然而，很少有研究调查人体直立站立时髋关节矢状位对线与脊柱骨盆失配之间的相互关系。我们的研究旨在调查：（I）脊柱骨盆失配与髋关节伸展之间的关系；（II）针对脊柱骨盆失配的髋关节伸展不足，即骨盆入射角（PI）-腰椎前凸（LL），是否会影响直立站立时的躯干倾斜度。
本研究为回顾性横断面研究。我们纳入了2017年11月至2022年6月期间在我院门诊接受骨质疏松治疗的398例连续女性患者。有以下任何一种情况的患者被排除在研究之外：（I）全脊柱X线平片未覆盖股骨的患者；（II）有椎体或下肢骨折的患者；（III）有脊柱或下肢手术史的患者；（IV）在前后位X线片上Cobb角≥10°的脊柱侧弯患者；（V）有移行椎的患者。根据矢状位脊柱对线情况，将62例患者分为正常组和对线不良组。患者接受全脊柱X线平片作为常规检查。在两组中获得代表髋关节伸展的骨盆股骨角（PFA）与PI-LL之间的线性近似值。通过将PI-LL代入正常组的线性近似值中，获得每位患者的最佳PFA。每位患者的最佳PFA与测量的PFA之间的差异定义为ΔPFA。在两组中评估ΔPFA与矢状垂直轴（SVA）之间的相关性。
两组中PFA与PI-LL均相关。对线不良组的ΔPFA明显大于正常组。仅在线形不良组中，ΔPFA与SVA相关。
ΔPFA的大小表明在直立站立时髋关节伸展不足，无法代偿脊柱骨盆失配。
