Cannestra Andrew F, Peterson Mark D, Parker Stephen R, Roush Thomas F, Bundy Justin V, Turner Alexander W
*Lyerly Neurosurgery, Jacksonville, FL †Southern Oregon Spine Care, Medford, OR ‡St Vincent's Brain and Spine Institute, Jacksonville, FL §Roush Spine, Lake Worth, FL ¶Augusta Orthopedic and Sports Medicine Specialist, PC, Augusta, GA ||NuVasive, Inc., San Diego, CA.
Spine (Phila Pa 1976). 2016 Apr;41 Suppl 8:S44-9. doi: 10.1097/BRS.0000000000001465.
Biomechanical study and review of literature on expandable lumbar interbody fusion constructs.
To evaluate the biomechanical stability of expandable interbody devices.
Lumbar interbody implants placed from an anterior or lateral approach are desirable due to their large size, providing a stable fusion environment. Posterior implants are typically limited by their access corridor. Expandable footprint transforaminal lumbar interbody fusion (TLIF) interbodies may allow for a minimally invasive TLIF approach with the biomechanical benefits of an anterior lumbar interbody fusion (ALIF)-sized graft; however, this requires experimental investigation.
Six cadaveric L1-sacrum segments were tested intact with pure moments of ± 7.5 N m in flexion-extension, lateral bending, and axial rotation. Specimens received at L4-5 either a medial-lateral expandable TLIF cage (MLX-TLIF) or a conventional polyether ether ketone (PEEK) banana-shaped TLIF cage (Conv-TLIF) first. Both were tested with unilateral and bilateral pedicle screw (PS) fixation. Testing was repeated with the alternate cage and fixation. Motion marker arrays were fixed to L4 and L5 to assess range of motion. Results were compared with published data for a PEEK ALIF cage with anterior plate and a PEEK ALIF cage with bilateral PS fixation, tested under the same conditions.
The most rigid construct was ALIF with bilateral PS fixation in flexion-extension and axial rotation, whereas MLX with bilateral PS was most rigid in lateral bending. Conv-TLIF with unilateral PS was the least rigid construct. MLX-TLIF with unilateral PS provided similar range of motion to Conv-TLIF with bilateral PS in flexion-extension and lateral bending, and ALIF with anterior plate in lateral bending.
The MLX-TLIF cage with unilateral PS fixation provided comparable stability to conventional TLIF with bilateral PS fixation and ALIF with anterior plate treatments. The large footprint of the expandable cage may reduce the TLIF supplemental fixation demands and facilitate minimally invasive single-position surgery. If needed, additional stability may be achieved by using bilateral PS.
N/A.
可扩张腰椎椎间融合器的生物力学研究及文献综述。
评估可扩张椎间装置的生物力学稳定性。
从前路或侧路置入的腰椎椎间植入物因其尺寸较大，能提供稳定的融合环境，故而备受青睐。后路植入物通常受限于其操作通道。具有可扩张底面的经椎间孔腰椎椎间融合术（TLIF）椎间融合器或许能实现微创TLIF手术，同时具备前路腰椎椎间融合术（ALIF）大小移植物的生物力学优势；然而，这需要进行实验研究。
对6个尸体L1 - 骶骨节段进行完整测试，在屈伸、侧弯和轴向旋转时施加±7.5 N·m的纯力矩。标本在L4 - 5水平首先置入一个内外侧可扩张TLIF融合器（MLX - TLIF）或一个传统聚醚醚酮（PEEK）香蕉形TLIF融合器（Conv - TLIF）。二者均采用单侧和双侧椎弓根螺钉（PS）固定进行测试。使用另一种融合器和固定方式重复测试。将运动标记阵列固定于L4和L5以评估活动范围。结果与在相同条件下测试的带前路钢板的PEEK ALIF融合器和双侧PS固定的PEEK ALIF融合器的已发表数据进行比较。
在屈伸和轴向旋转时，最坚固的结构是双侧PS固定的ALIF，而在侧弯时，双侧PS固定的MLX最坚固。单侧PS固定的Conv - TLIF是最不坚固的结构。单侧PS固定的MLX - TLIF在屈伸和侧弯时提供的活动范围与双侧PS固定的Conv - TLIF以及侧弯时带前路钢板的ALIF相似。
单侧PS固定的MLX - TLIF融合器提供的稳定性与双侧PS固定的传统TLIF以及带前路钢板的ALIF治疗相当。可扩张融合器的大底面或许能减少TLIF的辅助固定需求，并便于进行微创单节段手术。如有需要，可通过使用双侧PS实现额外的稳定性。
无。
