Anterior cervical discectomy and fusion

Sentinel sign in standalone anterior cervical fusion: Outcomes and fusion rate

Background

The authors aim to demonstrate the feasibility, outcomes and fusion rate of a standalone PEEK cage in the outpatient setting.

Methods

48 consecutive patients undergoing standalone ACDF (S-ACDF) (Group 1) were compared to control group of 49 patients who had ACDF with ACP (Group 2).

Results

Analysis of follow-up at the one year period postoperative outcomes between groups 1 and 2 demonstrated no intergroup statistical significant difference in VAS neck, arm and NDI scores p = 0.414, 0.06 and p = 0.328 respectively.

Conclusion

We conclude that S-ACDF can be safely done in an ambulatory surgery center with satisfactory clinical and patient-reported outcomes.

ACDF vs TDR for patients with cervical spondylosis - an 8 year follow up study

Background

ACDF has been considered as the gold standard in the treatment of single level cervical disk protrusion. However, it may cause adjacent level degeneration due to regional biomechanical changes. TDR has been applied with satisfactory results for over a decade, but there is no consensus if TDR is safer and more efficient than ACDF. The current study was carried out to compare the efficiency and safety of TDR and ACDF in the treatment of patients with single level cervical disk protrusion.

Methods

One hundred forty-five consecutive patients who underwent either TDR or ACDF in our center were included in the current study. Time of surgery, intraoperative blood loss, VAS arm and neck pain scores, ROM, ODI, SF36 and Patient satisfaction were compared before the surgery, after the surgery, and during follow up 1, 3, 5, 8 years after the surgery.

Results

The time of surgery was 64.6 ± 20.7 min in the ACDF group and 69.4 ± 19.3 min in the TDR group; intraoperative hemorrhage was 67.2 ± 14.3 ml in ACDF group and 70.7 ± 18.6 ml in TDR group. There were no significant differences between two groups concerning time of surgery and intraoperative blood loss. No differences were found concerning patient satisfaction between the two groups during the follow up (P > 0.05). Significant differences were found between the groups concerning VAS arm and neck pain scores, ROM, ODI and SF36 after the surgery and during the 8 year follow up.

Conclusion

TDR may be a more effective approach than ACDF for treating patients with single level cervical disk protrusion.

Keywords

Cervical disk herniation, ACDF, TDR, Retrospective study

Misaligned Versus Straight Placement of Anterior Cervical Plates: A Clinical and Radiologic Outcomes Study

BACKGROUND

In anterior cervical diskectomy and fusion (ACDF), misaligned plates are concerning because of the risk of screw-and-plate failure; however, these plates also hypothetically have the potential for asymmetric micromotion on the facet and uncovertebral joint. The aim of this study was to determine whether misaligned plate placement during ACDF had clinical benefits compared with straight plate placement.

METHODS

Postoperative AP radiographs of 128 consecutive patients who underwent ACDF with anterior cervical plate (ACP) fixation were reviewed, and plate alignment was assessed. Patients were separated into control group 1 (straight plates) or group 2 (misaligned plates).

RESULTS

The mean age of patients was 51.5 ± 0.9 years, and women represented 51% of the total population. There was no significant difference between groups with regard to the preoperative visual analog scale (VAS) and Neck Disability Index (NDI) scores (P = 0.744 and P = 0.943, respectively). At 6 weeks postoperatively, the VAS scores for group 1 decreased from 7.6 ± 0.2 to 4.0 ± 0.2 compared with the scores in group 2, which decreased from 7.7 ± 0.2 to 2.1 ± 0.1, which demonstrated statistical significance (P = 0.019). At 2-year follow-up, no significant difference was demonstrated between the groups' VAS and NDI scores (P = 0.670 and P = 0.266).

CONCLUSION

Misaligned plates have increased torsional strength and are associated with better clinical outcomes compared with those of straight plates in the early postoperative period. After fusion, no significant difference in clinical outcomes between the groups was noted, which may reduce the concerns regarding misaligned plates.

LEVEL OF EVIDENCE

Retrospective comparative study.

RESULTS OF TREATMENT OF CERVICAL DISCOPATHY WITH PEEK INTERBODY CAGES AT THREE LEVELS WITHOUT PLATE FIXATION

ABSTRACT Objective: To present the results of treatment of patients with cervical discopathy by anterior cervical approach, discectomy and placement of a PEEK interbody cage without anterior plate fixation. Methods: Retrospective, cross-sectional study from March 2013 to March 2015. Sixteen patients with radiculopathy or clinical signs of myelopathy were included; all patients underwent cervical surgery through anterior approach, discectomy, and placement of PEEK cages on three levels. Decompression levels were determined according to the correlation between preoperative radiological and clinical findings. Results: Sixteen patients predominantly male were included, with mean age of 50 years at the onset of the condition. Ten patients had involvement of C4-C5, C5-C6, C6-C7 levels, and six patients C3-C4, C4-C5 and C5-C6. Fourteen patients had cervicobrachialgia and two myelopathy. The preoperative visual analog scale average was 8/10 and the average postoperative value at 6 months was 3/10. At 6 months, there was no radiological evidence of recurrence. One patient had non-fatal complications. Conclusions: The treatment of cervical discopathy by anterior approach with interbody fusion with PEEK cage on three levels, with no plate fixation seemed to be safe and effective with better long-term results in terms of pain and myelopathy. The clinical results compare favorably with other similar series and, most importantly, the complications associated with anterior fixation plate are avoided.

Evaluation of glycerol-preserved bone allografts in cervical spine fusion: a prospective, randomized controlled trial

OBJECT

Bone allografts used for interbody spinal fusion are often preserved through either freeze drying or lowtemperature freezing, each having disadvantages related to graft preparation time and material properties. In response, a glycerol preservation treatment has been developed to maintain the biomechanical properties of allografts at ambient temperatures, requiring no thawing or rehydration and minimal rinsing prior to implantation. The authors conducted a prospective randomized study to compare the clinical results of glycerol-preserved Cloward dowels and those of freezedried Cloward dowels in anterior cervical discectomy and fusion. The primary outcome measures were evidence of fusion and graft subsidence, and the secondary outcome measures included adverse events, pain, and neck disability scores.

METHODS

Of 106 patients, 53 (113 levels of surgery) were randomly assigned to the glycerol-preserved graft group and 53 (114 levels of surgery) to the freeze-dried graft group. Subsidence was assessed at 3 and 6 months after implantation. Evidence of fusion was evaluated radiographically at 6 months postimplantation. Subsidence was quantitatively assessed based on physical measurements obtained from radiographs by using calibrated comparators, whereas fusion was also evaluated visually. Surgeons were blinded to treatment type during visual and physical assessments of the patients and the radiographs.

RESULTS

No one in either group had evidence of complete nonunion according to radiographic evaluation at the 6-month follow-up. Average subsidence for all graft-treated levels was 2.11 mm for the glycerol-preserved group and 2.73 mm for the freeze-dried group at the 3-month follow-up and 2.13 and 2.83 mm at the 6-month follow-up, respectively. The 2 treatment groups were statistically equivalent (p = 0.2127 and 0.1705 for the 3- and 6-month follow-up, respectively). No differences were noted between the graft types in terms of adverse event incidence or severity.

CONCLUSIONS

Glycerol-preserved bone allografts exhibit fusion results and subsidence values similar to those of their freeze-dried counterparts, potentially more favorable biomechanical properties, and significantly shorter preparation times.

Biomechanical comparison of a two-level anterior discectomy and a one-level corpectomy, combined with fusion and anterior plate reconstruction in the cervical spine

BACKGROUND

Common fusion techniques for cervical degenerative diseases include two-level anterior discectomy and fusion and one-level corpectomy and fusion. The aim of the study was to compare via in-vitro biomechanical testing the effects of a two-level anterior discectomy and fusion and a one-level corpectomy and fusion, with anterior plate reconstruction.

METHODS

Seven fresh frozen human cadaveric spines (C3-T1) were dissected from posterior musculature, preserving the integrity of ligaments and intervertebral discs. Initial biomechanical testing consisted of no-axial preload and 2Nm in flexion-extension, lateral bending and axial rotation. Thereafter, discectomies were performed at C4-5 and C5-6 levels, then two interbody cages and an anterior C4-C5-C6 plate was implanted. The flexibility tests were repeated and followed by C5 corpectomy and C4-C6 plate reconstruction. Biomechanical testing was performed again and statistical comparisons among the means of range of motion and axial rotation energy loss were investigated.

FINDINGS

The two-level cage-plate construct had significantly lower range of motion than the one-level corpectomy-plate construct (P≤0.03). Axial rotation energy loss was significantly (P≤0.03) greater for the corpectomy-plate construct than for the two-level cage-plate construct and the intact condition.

INTERPRETATION

A two-level cage-plate construct provides greater stability in flexion, extension and lateral bending motions when compared to a one-level corpectomy-plate construct. A two-level cage-plate is more likely to maintain axial balance by reducing the energy lost in axial rotation.