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Comparison of hybrid constructs with 2-level artificial disc replacement and 2-level anterior cervical discectomy and fusion for surgical reconstruction of the cervical spine: a kinematic study in whole cadavers.

Liu B, Zeng Z, Hoof TV, Kalala JP, Liu Z, Wu B - Med. Sci. Monit. (2015)

Bottom Line: Two-level ACDF resulted in increased ROM at C3-4 and C6-7 compared with intact spine.At C6-C7, the ICR was more posterior and superior than in the intact condition.The type of surgery had a significant impact on the ICR location.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China (mainland).

ABSTRACT

Background: Multi-level cervical degeneration of the spine is a common clinical pathology that is often repaired by anterior cervical discectomy and fusion (ACDF). The aim of this study was to investigate the kinematics of the cervical spine after hybrid surgery compared with 2-level ACDF.

Material and methods: Five freshly frozen, unembalmed whole human cadavers were used including 3 males and 2 females with a mean age of 51 ± 8 years. After evaluating the intact spine for range of motion (ROM), sagittal alignment and instantaneous center of rotation (ICR), each cadaver underwent 4 consecutive surgeries: 2-level artificial disc replacement (ADR) from C4 to C6 (ADR surgery); 2-level ACDF from C4 to C6 (ACDF surgery); hybrid C4-5 ACDF and C5-6 ADR (ACDF+ADR surgery); and hybrid C4-5 ADR and C5-6 ACDF (ADR+ACDF surgery). The ROM and ICR of adjacent intact segments (C3-4; C6-7), and whole sagittal alignment were revaluated.

Results: Two-level ACDF resulted in increased ROM at C3-4 and C6-7 compared with intact spine. ROM was significantly different to intact spine using ACDF surgery at C3-C4 and C6-C7 and ROM was increased with ACDF+ADR surgery at C6-C7 (all P<0.05). No improvement in sagittal alignment was observed with any approach. The localization of the ICR shifted upwards and anteriorly at C3-C4 after reconstruction. ICR changes at C3-C4 were greatest for ADR+ACDF surgery and were significantly different to ACDF surgery (P<0.05), but not between ADR surgery and ACDF+ADR surgery. At C6-C7, the ICR was more posterior and superior than in the intact condition. The greatest change in ICR was observed in ACDF surgery at the C6-C7 level, significantly different from the other groups (P<0.05).

Conclusions: For 2-level reconstruction, hybrid surgery and ADR did not alter ROM and minimally changed ICR at the adjacent-level. The type of surgery had a significant impact on the ICR location. This suggests that hybrid surgery may be a viable option for 2-level cervical surgery.

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Related in: MedlinePlus

Cervical spine measurements for the intact spine, artificial disc replacement from C4 to C6 (ADR), two-level anterior cervical discectomy and fusion from C4 to C6 (ACDF), and hybrid surgeries of C4–5 ACDF and C5–6 ARD (ACDF+ADR), and C4–5 ARD and C5–6 ACDF (ADR+ACDF) (A) Range of motion (ROM) for adjacent motion segments compared with intact spine (3 cycles/cadaver). * P<0.05 vs. the intact spine. (B) Sagittal alignment for adjacent motion segments compared with intact spine (3 cycles/cadaver): (C) Translational distance of instantaneous center of rotation (ICR) in each specimen (3 cycles/cadaver). # P<0.05 for ICR at C3–C4 between ACDF surgery and ADR+ACDF surgery. * P<0.05 for ICR at C6–C7 between ACDF+ADR surgery vs. the other 3 surgeries.
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f4-medscimonit-21-1031: Cervical spine measurements for the intact spine, artificial disc replacement from C4 to C6 (ADR), two-level anterior cervical discectomy and fusion from C4 to C6 (ACDF), and hybrid surgeries of C4–5 ACDF and C5–6 ARD (ACDF+ADR), and C4–5 ARD and C5–6 ACDF (ADR+ACDF) (A) Range of motion (ROM) for adjacent motion segments compared with intact spine (3 cycles/cadaver). * P<0.05 vs. the intact spine. (B) Sagittal alignment for adjacent motion segments compared with intact spine (3 cycles/cadaver): (C) Translational distance of instantaneous center of rotation (ICR) in each specimen (3 cycles/cadaver). # P<0.05 for ICR at C3–C4 between ACDF surgery and ADR+ACDF surgery. * P<0.05 for ICR at C6–C7 between ACDF+ADR surgery vs. the other 3 surgeries.

Mentions: The inter-orthopedist reliability was evaluated using the ICC, and demonstrated a good inter-observer reliability (ICC=0.82, 95%CI: 0.73–0.91). Analysis of kinematics demonstrated that there was no significant difference between the intact spine and 2-level ADR, according to ROM. Two-level ACDF resulted in a significant increase in ROM at C3–4 and C6–7 compared with the intact spine. Compared with the intact spine, the ROM at C3–C4 was significantly different using ACDF surgery. Compared with the intact spine, ROM at C6–C7 was significantly different after both ACDF surgery and ACDF+ADR surgery. In ACDF+ADR surgery, ROM was increased at C3–4 and C6–7 compared with intact spine; however, significant changes were noted only at lower levels (C6–C7) (P<0.05). In ADR+ACDF surgery, ROM in flexion and extension were increased at C3–4 and C6–7, but the differences were not significant compared with the intact spine (Figure 4A).


Comparison of hybrid constructs with 2-level artificial disc replacement and 2-level anterior cervical discectomy and fusion for surgical reconstruction of the cervical spine: a kinematic study in whole cadavers.

Liu B, Zeng Z, Hoof TV, Kalala JP, Liu Z, Wu B - Med. Sci. Monit. (2015)

Cervical spine measurements for the intact spine, artificial disc replacement from C4 to C6 (ADR), two-level anterior cervical discectomy and fusion from C4 to C6 (ACDF), and hybrid surgeries of C4–5 ACDF and C5–6 ARD (ACDF+ADR), and C4–5 ARD and C5–6 ACDF (ADR+ACDF) (A) Range of motion (ROM) for adjacent motion segments compared with intact spine (3 cycles/cadaver). * P<0.05 vs. the intact spine. (B) Sagittal alignment for adjacent motion segments compared with intact spine (3 cycles/cadaver): (C) Translational distance of instantaneous center of rotation (ICR) in each specimen (3 cycles/cadaver). # P<0.05 for ICR at C3–C4 between ACDF surgery and ADR+ACDF surgery. * P<0.05 for ICR at C6–C7 between ACDF+ADR surgery vs. the other 3 surgeries.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4403376&req=5

f4-medscimonit-21-1031: Cervical spine measurements for the intact spine, artificial disc replacement from C4 to C6 (ADR), two-level anterior cervical discectomy and fusion from C4 to C6 (ACDF), and hybrid surgeries of C4–5 ACDF and C5–6 ARD (ACDF+ADR), and C4–5 ARD and C5–6 ACDF (ADR+ACDF) (A) Range of motion (ROM) for adjacent motion segments compared with intact spine (3 cycles/cadaver). * P<0.05 vs. the intact spine. (B) Sagittal alignment for adjacent motion segments compared with intact spine (3 cycles/cadaver): (C) Translational distance of instantaneous center of rotation (ICR) in each specimen (3 cycles/cadaver). # P<0.05 for ICR at C3–C4 between ACDF surgery and ADR+ACDF surgery. * P<0.05 for ICR at C6–C7 between ACDF+ADR surgery vs. the other 3 surgeries.
Mentions: The inter-orthopedist reliability was evaluated using the ICC, and demonstrated a good inter-observer reliability (ICC=0.82, 95%CI: 0.73–0.91). Analysis of kinematics demonstrated that there was no significant difference between the intact spine and 2-level ADR, according to ROM. Two-level ACDF resulted in a significant increase in ROM at C3–4 and C6–7 compared with the intact spine. Compared with the intact spine, the ROM at C3–C4 was significantly different using ACDF surgery. Compared with the intact spine, ROM at C6–C7 was significantly different after both ACDF surgery and ACDF+ADR surgery. In ACDF+ADR surgery, ROM was increased at C3–4 and C6–7 compared with intact spine; however, significant changes were noted only at lower levels (C6–C7) (P<0.05). In ADR+ACDF surgery, ROM in flexion and extension were increased at C3–4 and C6–7, but the differences were not significant compared with the intact spine (Figure 4A).

Bottom Line: Two-level ACDF resulted in increased ROM at C3-4 and C6-7 compared with intact spine.At C6-C7, the ICR was more posterior and superior than in the intact condition.The type of surgery had a significant impact on the ICR location.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China (mainland).

ABSTRACT

Background: Multi-level cervical degeneration of the spine is a common clinical pathology that is often repaired by anterior cervical discectomy and fusion (ACDF). The aim of this study was to investigate the kinematics of the cervical spine after hybrid surgery compared with 2-level ACDF.

Material and methods: Five freshly frozen, unembalmed whole human cadavers were used including 3 males and 2 females with a mean age of 51 ± 8 years. After evaluating the intact spine for range of motion (ROM), sagittal alignment and instantaneous center of rotation (ICR), each cadaver underwent 4 consecutive surgeries: 2-level artificial disc replacement (ADR) from C4 to C6 (ADR surgery); 2-level ACDF from C4 to C6 (ACDF surgery); hybrid C4-5 ACDF and C5-6 ADR (ACDF+ADR surgery); and hybrid C4-5 ADR and C5-6 ACDF (ADR+ACDF surgery). The ROM and ICR of adjacent intact segments (C3-4; C6-7), and whole sagittal alignment were revaluated.

Results: Two-level ACDF resulted in increased ROM at C3-4 and C6-7 compared with intact spine. ROM was significantly different to intact spine using ACDF surgery at C3-C4 and C6-C7 and ROM was increased with ACDF+ADR surgery at C6-C7 (all P<0.05). No improvement in sagittal alignment was observed with any approach. The localization of the ICR shifted upwards and anteriorly at C3-C4 after reconstruction. ICR changes at C3-C4 were greatest for ADR+ACDF surgery and were significantly different to ACDF surgery (P<0.05), but not between ADR surgery and ACDF+ADR surgery. At C6-C7, the ICR was more posterior and superior than in the intact condition. The greatest change in ICR was observed in ACDF surgery at the C6-C7 level, significantly different from the other groups (P<0.05).

Conclusions: For 2-level reconstruction, hybrid surgery and ADR did not alter ROM and minimally changed ICR at the adjacent-level. The type of surgery had a significant impact on the ICR location. This suggests that hybrid surgery may be a viable option for 2-level cervical surgery.

Show MeSH
Related in: MedlinePlus