Cervical total disc replacement exhibits similar stiffness to intact cervical functional spinal units tested on a dynamic pendulum testing system

Comparison of clinical outcomes of modified laminoplasty with preservation of muscle group inserted into C2 and C7 spinous processes versus conventional C3-C7 laminoplasty: a prospective, randomized, controlled, noninferiority trial

BACKGROUND

The efficacy and noninferior of performing modified double-door laminoplasty (MDDL) (C4-C6 laminoplasty plus C3 laminectomy, alongside a dome-like resection of the inferior part of the C2 lamina and the superior part of the C7 lamina) in patients with multilevel cervical spondylotic myelopathy (MCSM) is equivocal. A randomized, controlled trial is warranted.

OBJECTIVE

The objective was to evaluate the clinical efficacy and noninferior of MDDL compared with traditional C3-C7 double-door laminoplasty.

STUDY DESIGN

A single-blind, randomized, controlled trial.

METHODS

A single-blind, randomized, controlled trial was conducted in which patients who with MCSM with greater than or equal to 3 levels of spinal cord compression from the C3 to the C7 vertebral levels were enrolled and assigned to undergo either MDDL group or conventional double-door laminoplasty (CDDL) group in a 1:1 ratio. The primary outcome was the change in the Japanese Orthopedic Association score from baseline to 2-year follow-up. The secondary outcomes included changes in the Neck Disability Index (NDI) score, the Visual Analog Scale (VAS) for neck pain, and imaging parameters. Operative complications were also collected and reported. The outcome measures were compared between the groups at 3 months, 1 year, or 2 years after surgery.

RESULTS

A total of 96 patients (mean age 67 years, 39.8% women) underwent randomization. Of these patients, 93 completed 3-month follow-up, 79 completed 1-year follow-up, and 66 completed 2-year follow-up. The changes in the Japanese Orthopedic Association score did not differ significantly between the study groups at the three time points after surgery. With respect to amelioration of neck pain and disability related to neck pain, patients in the MDDL group had a significantly greater decrease in the VAS and NDI component summary score than did those in the CDDL group at 1-year (VAS: -2.5 vs. -3.2, difference -0.7, 95% CI -1.1 to -0.2, P =0.0035; NDI: -13.6 vs. -19.3, difference -5.7, 95% CI -10.3 to -1.1, P =0.0159) and 2-years (VAS: -2.1 vs. -2.9, difference -0.8, 95% CI -1.4 to -0.2, P =0.0109; NDI: -9.3 vs. -16.0, difference -6.7, 95% CI -11.9 to -1.5, P =0.0127). The changes in the range of motion (ROM), the C2-C7 Cobb angle, and the cervical sagittal vertical axis in the MDDL group were significantly less than those in the CDDL group (ROM: -9.2±6.4 vs. -5.0±6.0, P =0.0079; C2-C7 Cobb angle: -7.9±7.8 vs. -4.1±6.2, P =0.0345; cervical sagittal vertical axis: 0.6±0.9 vs. 0.2±0.6, P =0.0233). The MDDL group had less blood loss (428.1 vs. 349.1, P =0.0175) and a lower rate of axial symptoms (27.3 vs. 6.1%, P =0.0475) than the CDDL group.

CONCLUSIONS

Among patients with MCSM, the MDDL produced similar cervical cord decompression compared with the conventional C3-C7 double-door laminoplasty. The modified laminoplasty was associated with meaningful improvement in amelioration of neck discomfort, maintaining a better cervical ROM and sagittal alignment, decreasing blood loss, and reducing the incidence of axial symptoms.

C2 Dome-Like Expansive Laminoplasty Versus C2 Open-Door Laminoplasty for Treating Multilevel Cervical Ossification of the Posterior Longitudinal Ligament Involving C2

BACKGROUND

There are controversies over the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) involving C2.

OBJECTIVE

To compare the outcomes of C2 dome-like expansive laminoplasty (C2DL) and C2 open-door laminoplasty (C2OL) for treating cervical OPLL involving C2.

METHODS

The data of 36 patients undergoing C2OL and 40 patients treated with C2DL because of cervical OPLL involving C2 were retrospectively analyzed. The functional outcomes of the Japanese Orthopedic Association score, Neck Disability Index, 36-Item Short Form Health Survey score, and visual analog scale score for neck pain were compared between the 2 groups. The C2-C7 Cobb angle, cervical range of motion (ROM), and space available for the spinal cord at C2 were measured.

RESULTS

At the final follow-up, the Japanese Orthopedic Association score, Neck Disability Index, and 36-Item Short Form Health Survey score significantly improved in both groups (all P < .05), but with no significant intergroup differences (all P > .05). The visual analog scale score for neck pain reduced significantly in both groups (P < .05), but the patients in the C2OL group experienced more severe neck axial pain (P < .05). The C2-C7 Cobb angle and cervical ROM reduced greatly in both groups (P < .05), but those in the C2OL group decreased more (P < .05). The spinal cord at C2 significantly improved in both groups (P < .05), with no significant intergroup differences (P > .05).

CONCLUSION

C2DL was superior to C2OL in maintaining the cervical alignment and ROM and reducing neck axial pain for treating OPLL involving C2.

Double Dome Laminoplasty: A Novel Technique for C2 Decompression

Objective

To introduce a new surgical technique - double dome laminoplasty for decompression of the entire C2 lamina and preservation of an extensor muscle insertion.

Methods

Eleven consecutive cervical myelopathy patients due to ossification of the posterior longitudinal ligament involving the Axis (C2) area were contained at this study. Direct decompression was evaluated as an increasing rate in space available cord (%) and posterior cord shift (mm) at C2 level. The Japanese Orthopaedic Association (JOA) score, visual analogue scale, and C2–7 Cobb angle in a neutral lateral x-ray were analyzed.

Results

The mean increase in space available for spinal cord at the C2 level, average posterior cord shift, and JOA recovery rate were 69.7%, 5.3±0.15 mm, and 58.0%, respectively. Cervical lordotic angle was maintained in all patients. One patient reported neck pain (visual analogue scale 6) postoperatively. No specific complications such as C2 laminar fracture or insufficient decompression were observed.

Conclusion

We recommend double dome laminoplasty for treating patients with cervical myelopathy involving the C2 area to avoid C2 laminectomy, reduce postoperative neck pain, and maintain lordotic cervical spine alignment.

Application of a modified surgical position in anterior approach for total cervical artificial disc replacement

BACKGROUND

Total cervical artificial disc replacement (TDR) has been considered a safe and effective alternative surgical treatment for cervical spondylosis and degenerative disc disease that have failed to improve with conservative methods. Positioning the surgical patient is a critical part of the procedure. Appropriate patient positioning is crucial not only for the safety of the patient but also for optimizing surgical exposure, ensuring adequate and safe anesthesia, and allowing the surgeon to operate comfortably during lengthy procedures. The surgical posture is the traditional position used in anterior cervical approach; in general, patients are in a supine position with a pad under their shoulders and a ring-shaped pillow under their head.

AIM

To investigate the clinical outcomes of the use of a modified surgical position versus the traditional surgical position in anterior approach for TDR.

METHODS

In the modified position group, the patients had a soft pillow under their neck, and their jaw and both shoulders were fixed with wide tape. The analyzed data included intraoperative blood loss, position setting time, total operation time, and perioperative blood pressure and heart rate.

RESULTS

Blood pressure and heart rate were not significantly different before and after body positioning in both groups (P > 0.05). Compared with the traditional position group, the modified position group showed a statistically significantly longer position setting time (P < 0.05). However, the total operation time and intraoperative blood loss were significantly reduced in the modified position group compared with the traditional position group (P < 0.05).

CONCLUSION

The clinical outcomes indicated that total operation time and intraoperative blood loss were relatively lower in the modified position group than in the traditional position group, thus reducing the risks of surgery while increasing the position setting time. The modified surgical position is a safe and effective method to be used in anterior approach for TDR surgery.

Modified Laminoplasty Preserving the Posterior Deep Extensor Insertion into C2 Improves Clinical and Radiologic Results Compared with Conventional Laminoplasty: A Meta-Analysis

BACKGROUND

Whether modified laminoplasty is better than conventional laminoplasty is unclear. Thus, a meta-analysis comparing the outcomes of preserving or repairing the posterior deep extensor insertion to C2 in laminoplasty was conducted for patients with multilevel cervical spondylotic myelopathy (MCSM).

METHODS

Several electronic databases were chosen to search for relevant studies. The primary indices included preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, JOA recovery rate, muscle atrophy rate, preoperative and postoperative range of motion (ROM), ROM decrease rate, and incidence of axial pain. Results are expressed as odds ratios with 95% confidence intervals for the dichotomous outcomes and mean differences for continuous outcomes.

RESULTS

Eight studies involving 763 patients were included in this study. The postoperative cervical ROM was significantly higher in the modified group (P = 0.01, MD = 3.0 [0.66, 5.35]), as was the cervical posterior muscle volume (P = 0.02, MD = 28.28 [4.42, 52.3]) and the operation time (MD = -45.04, 95% CI -49.79, -40.29; P < 0.01). The incidence of axial symptoms in the modified group was lower than that in the conventional group (P < 0.01, OR 0.28 [0.17, 0.46]), as was the rate of decrease of cervical ROM (P = 0.004, MD = -6.72 [-11.25, 2.19]). There was no significant difference (P > 0.05) between the groups in blood loss, preoperative and postoperative JOA score, or JOA recovery rate.

CONCLUSIONS

Modified laminoplasty had shorter operation times, a lower incidence of axial pain, a higher cervical ROM, and a lower atrophy rate compared with conventional laminoplasty. The clinical and radiologic results of modified laminoplasty have been partly superior to those of conventional laminoplasty to date.