Department of Orthopaedic Surgery, Pinnacle Orthopaedics, Austelle, GA, USA.
Spine (Phila Pa 1976). 2010 Mar 1;35(5):526-30. doi: 10.1097/BRS.0b013e3181bb0e6e.
An in vivo biomechanical anterior cervical discectomy and instrumented fusion (ACDFI) model employing a calibrated distractor and a subminiature load cell used to intraoperatively measure distractive force across the discectomy site and subsequent compressive force across the interbody load cell following distractor removal.
To determine the relationship between the distractive force and resultant initial graft compression in an in vivo ACDFI model.
The relationship between the distractive force and subsequent graft compression following distractor removal has not been studied in an in vivo ACDFI model. The consequences of over or under distraction and its subsequent effect on graft compression with regards to axial neck pain, endplate failure with graft subsidence, and fusion rates is an area of clinical significance for ACDFI.
Intraoperative measurements were obtained from 17 discectomy sites in 12 patients undergoing one and two level ACDFI. Informed consent was obtained from all subjects before surgery. A calibrated Caspar distractor was used to measure the distraction across the discectomy site and a subminiature interbody load cell was placed into the discectomy site and used to measure the resultant initial compressive force following distractor removal. The statistical significance and correlation between the distractive force across the discectomy site and the subsequent compressive force across the load cell were investigated with the Pearson correlation coefficient.
The average distractive force across the discectomy site was 33.5 +/- 11.6 lbs and the subsequent compressive force across the interbody load cell was 16.9 +/- 5.9 lbs following distractor removal. The Pearson correlation coefficient was r = 0.912 (P < 0.0005). The data showed a statistically significant linear correlation between the distractive force and the subsequent compressive force across the range of distraction investigated.
This study demonstrated a statistically significant linear correlation between the distractive force applied across the discectomy site and the subsequent compressive force across a load cell placed in the interbody space following distractor removal in an in vivo ACDFI model.
采用校准牵开器和微型负载细胞的体内颈椎前路椎间盘切除术和器械融合（ACDFI）模型，用于术中测量椎间盘切除部位的牵开力以及牵开器去除后椎间负载细胞的后续压缩力。
确定体内 ACDFI 模型中牵开力与初始移植物压缩之间的关系。
在体内 ACDFI 模型中，尚未研究牵开器去除后牵开力与随后的移植物压缩之间的关系。牵开过度或不足及其随后对移植物压缩的影响，以及与轴向颈部疼痛、移植物下沉伴终板失败和融合率有关的问题，是 ACDFI 的一个临床重要领域。
对 12 例接受单节段和双节段 ACDFI 的 17 个椎间盘切除术部位进行术中测量。所有受试者均在手术前获得知情同意。使用校准的 Caspar 牵开器测量椎间盘切除部位的牵开力，并将微型椎间负载细胞放置在椎间盘切除部位，用于测量牵开器去除后产生的初始压缩力。使用 Pearson 相关系数研究椎间盘切除部位的牵开力与负载细胞的后续压缩力之间的统计学意义和相关性。
椎间盘切除部位的平均牵开力为 33.5 +/- 11.6 磅，牵开器去除后椎间负载细胞的后续压缩力为 16.9 +/- 5.9 磅。Pearson 相关系数为 r = 0.912（P < 0.0005）。数据显示，在所研究的牵开范围内，牵开力与随后的压缩力之间存在统计学显著的线性相关性。
本研究在体内 ACDFI 模型中证明，椎间盘切除部位的牵开力与牵开器去除后椎间负载细胞的后续压缩力之间存在统计学显著的线性相关性。
