Liebsch Christian, Obid Peter, Vogt Morten, Schlager Benedikt, Wilke Hans-Joachim
Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, Ulm University Medical Centre, Helmholtzstraße 14, 89081, Ulm, Germany.
Department of Orthopaedics and Trauma Surgery, Freiburg University Medical Centre, Freiburg, Germany.
Sci Rep. 2024 Dec 16;14(1):30496. doi: 10.1038/s41598-024-82132-0.
Scoliosis instrumentation length depends on the type and degree of deformity and the individual preference of the surgeon. This in vitro study aimed to explore effects of increasing instrumentation length on adjacent segment mobility and intervertebral disc loading. Six fresh frozen human spine specimens (C7-sacrum) with entire rib cage from young adult donors (26-45 years) were loaded with pure moments of 5 Nm. Range of motion (ROM) of all segments was determined using optical motion tracking. Lumbar intradiscal pressure (IDP) was measured using flexible pressure sensors from L1 to L5. The specimens were tested in two groups with increasing posterior instrumentation length in proximal (group 1) and distal direction (group 2). Significant (p < 0.05) adjacent segment ROM increases compared to the condition without any instrumentation and compared to other instrumentations were primarily found proximally to the instrumentation in lateral bending. IDP significantly (p < 0.05) increased in flexion in the distal adjacent segment for T4-L1 instrumentation and by up to 550% at instrumented levels compared to the condition without instrumentation. These findings may explain clinical complications such as adjacent segment disease and associated proximal and distal junctional kyphosis. To reduce loads on adjacent segments, instrumentation should therefore be applied as short as reasonable.
脊柱侧弯内固定长度取决于畸形的类型和程度以及外科医生的个人偏好。这项体外研究旨在探讨增加内固定长度对相邻节段活动度和椎间盘负荷的影响。从年轻成年供体（26 - 45岁）获取了六个带有完整胸廓的新鲜冷冻人体脊柱标本（C7 - 骶骨），施加5 Nm的纯力矩。使用光学运动跟踪确定所有节段的活动范围（ROM）。使用柔性压力传感器测量L1至L5的腰椎椎间盘内压力（IDP）。标本分为两组进行测试，分别在近端（第1组）和远端方向（第2组）增加后路内固定长度。与无任何内固定的情况相比，以及与其他内固定相比，主要在侧弯时内固定近端的相邻节段ROM有显著（p < 0.05）增加。对于T4 - L1内固定，远端相邻节段在屈曲时IDP显著（p < 0.05）增加，与无内固定的情况相比，在植入节段IDP增加高达550%。这些发现可能解释了诸如相邻节段疾病以及相关的近端和远端交界性后凸等临床并发症。因此，为了减轻相邻节段的负荷，内固定应尽可能合理地缩短使用长度。
