Preoperative severity of facet joint degeneration does not impact the 2-year clinical outcomes and cervical imbalance following laminoplasty

Novel Risk Factors for Cervical Facet Joint Degeneration in the Subaxial Cervical Spine: Correlation with Cervical Sagittal Alignment and Bone Mineral Density

OBJECTIVE

The impact of cervical sagittal alignment on cervical facet joint degeneration (CFD) and the risk factors for CFD in patients with degenerative cervical myelopathy (DCM) were investigated in the current study.

METHODS

A total of 250 surgical patients with DCM were recruited. The clinical data and radiographical characteristics, including CFD, cervical sagittal balance parameters, Hounsfield unit (HU) values, disc degeneration (DD), and modic change, were collected. The detailed correlation between these characteristics and CFD was analyzed. Characteristics, including CFD, were compared among the various cervical alignment types and different CFD groups. Finally, the risk factors for CFD were revealed via logistic regression.

RESULTS

CFD was prevalent in DCM patients. Age, cervical sagittal vertical axis (cSVA), range of motion, T1 slope, thoracic inlet angle, DD, HU value, and modic change correlated with CFD segmentally and globally (P < 0.05). The lordosis and sigmoid types had a significantly higher CFD prevalence (P < 0.05). Furthermore, the average CFD threshold for the severe CFD group was 1.625 (area under the curve, 0.958). Additionally, 167 patients with average CFD <1.625 and 83 patients with CFD of ≥1.625 were classified into the mild CFD group and severe CFD group, respectively. Finally, multivariate analysis was performed, and age, cSVA, HU value, modic change, and DD were determined to be independent risk factors for CFD.

CONCLUSIONS

The load distribution tends to shift to a more shear-like pattern in the sigmoid and kyphosis types and in those with a higher cSVA, thereby promoting CFD. Aging, cervical malalignment, low bone mineral density, DD, and modic change were revealed to result in high risks of CFD.

Does cervical facet degeneration impact surgical outcomes and sagittal balance in patients with radiculopathy?

Purpose

In our present study, we aimed to investigate (1) whether cervical facet degeneration (FD) affects the clinical functional scores of patients with cervical radiculopathy after single-segment anterior cervical discectomy fusion (ACDF) and (2) whether FD affects the sagittal parameters of the cervical spine.

Methods

A total of 120 enrolled patients who underwent single-segment ACDF for radiculopathy with more than 2 years of follow-up were classified into two groups based on whether the preoperative mean FD was greater than or less than the mean FD grading score: mild FD group (mean score ≤ 2, n = 102) or severe FD group (mean score > 2, n = 48). Sagittal alignment changes and clinical functional scores were compared between the 2 groups. The relevant factors for FD were identified using multivariate logistic regression.

Results

Age, duration of symptoms, disc height and interfacet distance were independently associated with preoperative FD (age: P < 0.001; duration of symptoms: P = 0.020; disc height: P < 0.001; interfacet distance: P = 0.045). Compared with the mild FD group, the preoperative VAS (neck pain) score and NDI of the severe FD group were also higher, and the improvement of neck symptoms was better during the follow-up period. However, all clinical scores and radiographic parameters showed no significant differences during the 2-year follow-up. Additionally, no significant differences in the sagittal parameter changes were presented.

Conclusion

Patients with severe FD tended to experience more severe neck pain before surgery and greater improvement of neck symptoms at the follow-up visit. However, 2-year clinical efficacy and sagittal alignment after ACDF may not be markedly affected by preoperative FD severity. ACDF is considered to be a good choice for patients with radiculopathy, especially for patients with severe FD.

Laminoplasty-an underutilized procedure for cervical spondylotic myelopathy

BACKGROUND CONTENT

Cervical laminoplasty (LP) and laminectomy and fusion (LF) are commonly used surgical techniques for cervical spondylotic myelopathy (CSM). Several recent studies have demonstrated superior perioperative metrics and decreased overall costs with LP, yet LF is performed far more often in the United States.

PURPOSE

To determine the percentage of patients with CSM who are radiographically candidates for LP.

STUDY DESIGN

Retrospective comparative cohort study.

PATIENT SAMPLE

Patients >18 years old who underwent LF or LP for CSM at 2 large academic institutions from 2017 to 2019.

OUTCOME MEASURES

Candidacy for LP based on radiographic criteria.

METHODS

Radiographs were assessed by 2 spine surgeons not involved in the care of the patients to determine the C2-C7 Cobb angle and the presence and extent of cervical instability. Patients with kyphosis >13°, > 3.5 mm of listhesis on static imaging, or > 2.5 mm of motion on flexion-extension or standing-supine films were not considered candidates for LP. Intraclass coefficient (ICC) was calculated to assess the interobserver reliability of angular measurements and the presence of instability. The percentage of patients for whom LP was contraindicated was calculated.

RESULTS

One hundred eight patients underwent LF while 142 underwent LP. Of the 108 patients who underwent LF, 79.6% were radiographically deemed candidates for LP, as were all 142 patients who underwent LP. The ICC for C2-C7 alignment was 0.90; there was 97% agreement with respect to the presence of instability.

CONCLUSIONS

In 250 patients with CSM, 228 (91.2%) were radiographically candidates for LP. These data suggest that LP may be an underutilized procedure for the treatment for CSM.

The Severity of Cervical Disc Degeneration Does Not Impact 2-year Postoperative Outcomes in Patients With Cervical Spondylotic Myelopathy Who Underwent Laminoplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to evaluate the impact of cervical disc degeneration (CDD) severity on 2-year postoperative outcomes following laminoplasty.

SUMMARY OF BACKGROUND DATA

The impact of CDD on postoperative outcomes of cervical laminoplasty has not been well established.

METHODS

A total of 144 patients who underwent open-door laminoplasty for cervical spondylotic myelopathy (CSM) were enrolled. Six cervical discs were independently analyzed for degeneration severity using a previously reported grading system (grade 0: none, grade 3: severest). The relationship between the segmental range of motion (ROM) and the severity of CDD was evaluated. Subsequently, after dividing overall patients into mild and severe CDD groups by the average of CDD scores, the mixed-effect model was applied to assess 2-year postoperative outcomes, including physician-assessed myelopathy scores, patient-reported outcomes, and preoperative radiographic parameters. Finally, as additional analysis, the severe CDD group was further divided into two groups: group 1 included patients with a grade 3 CDD change in their most stenotic level and group 2 included the others. The 2-year postoperative myelopathy score was compared between groups 1 and 2.

RESULTS

The cervical segments with grade 3 CDD showed significantly smaller ROM compared with those with grade 0, 1, or 2 CDD (P < 0.01). There were no significant differences in postoperative improvements in myelopathy, pain, patient-reported physical and mental status, and radiographic parameters, except for quality of life (QOL) scores between CDD groups. A significant (P = 0.02) postoperative improvement in QOL scores was noted in the severe CDD group. In an additional analysis, myelopathy score at 2 years postoperatively was significantly higher in group 1 than group 2 (P = 0.041).

CONCLUSION

The severity of CDD did not negatively impact 2-year postoperative laminoplasty outcomes. The postulated reason is that the decreased segmental instability in the level with severe CDD may affect surgical outcomes positively.

LEVEL OF EVIDENCE

3.

The relationship between preoperative cervical sagittal balance and clinical outcome of laminoplasty treated cervical ossification of the posterior longitudinal ligament patients

BACKGROUND CONTEXT

Laminoplasty is a common surgical method used to treat patients with cervical ossification of the posterior longitudinal ligament (OPLL). Although laminoplasty is preferred over traditional laminectomy, the factors affecting the complications and outcomes are unclear. Recently, sagittal balance indexes have been revealed to be predictors of clinical outcomes in patients with cervical degenerative diseases, but their relationships with laminoplasty-treated OPLL outcomes remains unknown.

PURPOSE

The purpose of this study is to evaluate the relationship of preoperative cervical sagittal balance indexes and clinical outcome in laminoplasty treated OPLL patients.

STUDY DESIGN

This is a retrospective case study.

PATIENT POPULATION

Between January 2015 and January 2017, 181 consecutively included patients who underwent cervical laminoplasty for OPLL were enrolled (male:female ratio=126:75; mean age=60.2 years). Cervical spine lateral radiographs in neutral, flexion, and extension positions were taken before and 2 years after the surgery.

OUTCOME MEASURES

The C2-C7 Cobb angle, T1 slope, C1-C7 sagittal vertical axis (SVA), C2-C7 SVA, CGH (center of gravity of the head)-C7 SVA, cervical JOA (Japanese Orthopedic Association) score, and neck VAS (visual analogue scale) score were measured preoperatively and postoperatively at the 2-year follow-up.

METHODS

The patients were divided into two groups according to changes in the lordotic angle or the recovery rate of the JOA score. The relationships between the postoperative lordosis loss or the clinical outcome and the preoperative variables, including the patient's age, JOA score, C2-C7 Cobb angle, T1 slope, C1-C7 SVA, C2-C7 SVA, and CGH-C7 SVA, were investigated.

RESULTS

The patients were divided into two groups according to the postoperative change in the C2-C7 Cobb angle. There were no differences in the age, preoperative C2-C7 Cobb angle, C1-C7 SVA, or C2-C7 SVA; there was only a difference in the preoperative CGH-C7 SVA and T1 slope level (p=.038, p=.042). The postoperative JOA and JOA recovery rate were related to the postoperative lordosis loss in cervical alignment (p=.048, p=.031). We again divided the patients into two groups according to the JOA recovery rate and found that only the preoperative CGH-C7 SVA and C1-C7 SVA were related to the neurological outcome (p=.011, p=.047). According to the multivariate logistic regression analysis, higher preoperative CGH-C7 SVA levels were significantly associated with decreases in the lordosis angle postoperatively and the clinical outcome (p=.018, OR=1.225; p=.034, OR=1.654). The ROC (receiver operating characteristic) analysis revealed that the proper cutoff value of preoperative CGH-C7 SVA for predicting the postoperative loss of lordosis and clinical outcomes is 3.8 cm.

CONCLUSION

Preoperative cervical sagittal balance indexes are related to the outcomes of OPLL patients after laminoplasty. Patients with high preoperative CGH-C7 SVA levels have a high probability of developing sagittal imbalances and neurological symptoms of the cervical spine, and this measurement can be used as a predictor of outcomes in laminoplasty-treated cervical OPLL patients.