Is it Better to Stop at C2 or C3/4 in Elective Posterior Cervical Decompression and Fusion?

Does Ending a Posterior Construct Proximally at C2 Versus C3 Impact Patient Reported Outcomes in Degenerative Cervical Myelopathy Patients up to 24 months After the Surgery?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The primary objective was to evaluate the impact of the upper instrumented level (UIV) being at C2 vs C3 in posterior cervical construct on patient reported outcomes (PROs) up to 24 months after surgery for cervical degenerative myelopathy (DCM). Secondary objectives were to compare operative time, intra-operative blood loss (IOBL), length of stay (LOS), adverse events (AEs) and re-operation.

METHODS

Patients who underwent a posterior cervical instrumented fusion (3 and + levels) with a C2 or C3 UIV, with 24 months follow-up were analyzed. PROs (NDI, EQ5D, SF-12 PCS/MCS, NRS arm/neck pain) were compared using ANCOVA. Operative duration, IOBL, AEs, and re-operation were compared. Subgroup analysis was performed on patient presenting with pre-operative malalignment (cervical sagittal vertical axis ≥40 mm and/or T1slope- cervical lordosis >15°).

RESULTS

173 patients were included, of which 41 (24%) had a C2 UIV and 132 (76%) a C3 UIV. There was no statistically significant difference between the groups for the changes in PROs up to 24 months. Subgroup analysis of patients with pre-operative malalignment showed a trend towards greater improvement in the NDI at 12 months with a C2 UIV (P = .054). Operative time, IOBL and peri-operative AEs were more in C2 group (P < .05). There was no significant difference in LOS and re-operation (P > .05).

CONCLUSION

In this observational study, up to 24 months after surgery for posterior cervical fusion in DCM greater than 3 levels, PROs appear to evolve similarly.

Stopping at C2 Versus C3/4 in Elective Posterior Cervical Decompression and Fusion: A 5-Year Follow-up Study

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

In patients undergoing elective posterior cervical laminectomy and fusion (PCLF) with a minimum of 5-year follow-up, we sought to compare reoperation rates between patients with an upper instrumented vertebra (UIV) of C2 versus C3/4.

SUMMARY OF BACKGROUND DATA

The long-term outcomes of choosing between C2 versus C3/4 as the UIV in PCLF remain unclear.

METHODS

A single-institution, retrospective cohort study from a prospective registry was conducted of patients undergoing elective, degenerative PCLF from December 2010 to June 2018. The primary exposure was UIV of C2 versus C3/4. The primary outcome was reoperation. Multivariable logistic regression controlled for age, smoking, diabetes, and fusion to the thoracic spine.

RESULTS

Of the 68 patients who underwent PCLF with 5-year follow-up, 27(39.7%) had a UIV of C2, and 41(60.3%) had a UIV of either C3/4. Groups had similar duration of symptoms (P=0.743), comorbidities (P>0.999), and rates of instrumentation to the thoracic spine (70.4% vs. 53.7%, P=0.210). The C2 group had significantly longer operative time (231.8±65.9 vs. 181.6±44.1 mins, P<0.001) and more fused segments (5.9±1.8 vs. 4.2±0.9, P<0.001). Reoperation rate was lower in the C2 group compared with C3/4 (7.4% vs. 19.5%), though this did not reach statistical significance (P=0.294). Multivariable logistic regression showed increased odds of reoperation for the C3/4 group compared with the C2 group (OR=3.29, 95%CI=0.59-18.11, P=0.170), though statistical significance was not reached. Similarly, the C2 group had a lower rate of instrumentation failure (7.4% vs. 12.2%, P=0.694) and adjacent segment disease/disk herniation (0% vs. 7.3%, P=0.271), though neither trend attained statistical significance.

CONCLUSIONS

Patients with a UIV of C2 had less than half the number of reoperations and less adjacent segment disease, though neither trend was statistically significant. Despite a lack of statistical significance, whether a clinically meaningful difference exists between UIV of C2 versus C3/4 should be validated in larger samples with long-term follow-up.

LEVEL OF EVIDENCE

Level-3.

Surgical Outcomes of Extensive Dome-Like Laminoplasty Using En Bloc Resection of C2 Inner Lamina for Patients With Severe Cord Compression Behind C2 Body

STUDY DESIGN

A retrospective, single-center study.

OBJECTIVE

The aim of this study is to evaluate the efficacy and safety of a newly developed extensive dome-like laminoplasty using en bloc resection of the C2 inner lamina in patients with severe cord compression behind the C2 body.

SUMMARY OF BACKGROUND DATA

A surgery for severe cord compression behind C2 body is challenging for spinal surgeons. To date, there has been no established solution for severe cord compression behind the C2 body.

MATERIALS AND METHODS

Patients with severe cord compression behind the C2 body who underwent posterior surgery consecutively were enrolled. Extensive dome-like laminoplasty that was newly developed was performed to remove en bloc removal of the C2 inner lamina were performed. Preoperative and postoperative canal diameters behind the C2 and mean removed area of the C2 inner lamina were measured using MRI and CT scan. Clinical and radiographic parameters were assessed preoperative and postoperative periods. In addition, perioperative complications were analyzed.

RESULTS

A total of 36 patients underwent extensive dome-like laminoplasty and their diagnoses were ossification of the posterior longitudinal ligament (OPLL, 66.7%) and congenital stenosis with spondylosis (33.3%). The mean canal diameter behind the C2 increased from 9.85 (2.28) mm preoperatively to 19.91 (3.93) mm at the last follow-up ( P <0.001). Clinically, neck and arm visual analog scale, Japanese Orthopaedic Association score, and neck disability index significantly improved at postoperative 1 month ( P <0.05), and the scores were maintained until the last follow-up. No meaningful radiographic changes occurred after the surgeries. During the procedures, there were no particular complications, but one patient showed deteriorated myelopathic symptoms and underwent additional C1-C2 decompressive surgery.

CONCLUSIONS

After extensive dome-like laminoplasty, surgical outcomes are satisfactory, and complications are rare. This technique may be a viable option for patients with severe cord compression behind the C2 body.

LEVEL OF EVIDENCE

Level IV.

Is It Necessary to Cross the Cervicothoracic Junction in Posterior Cervical Decompression and Fusion for Multilevel Degenerative Cervical Spine Disease? A Systematic Review and Meta-Analysis

BACKGROUND

Posterior cervical decompression and fusion (PCF) is a common procedure for treating patients with multilevel degenerative cervical spine disease. The selection of lower instrumented vertebra (LIV) relative to the cervicothoracic junction (CTJ) remains controversial. This study aimed to compare the outcomes of PCF construct terminating at the lower cervical spine and crossing the CTJ.

METHODS

A comprehensive literature search was performed for relevant studies in the PubMed, EMBASE, Web of Science, and Cochrane Library database. Complications, rate of reoperation, surgical data, patient-reported outcomes (PROs), and radiographic outcomes were compared between PCF construct terminating at or above C7 (cervical group) and at or below T1 (thoracic group) in patients with multilevel degenerative cervical spine disease. A subgroup analysis based on surgical techniques and indications was performed.

RESULTS

Fifteen retrospective cohort studies comprising 2071 patients (1163 in the cervical group and 908 in the thoracic group) were included. The cervical group was associated with a lower incidence of wound-related complications (RR, 0.58; 95% CI 0.36 to 0.92, p = 0.022; 831 patients in cervical group vs. 692 patients in thoracic group), a lower reoperation rate for wound-related complications (RR, 0.55; 95% CI 0.32 to 0.96, p = 0.034; 768 vs. 624 patients), and less neck pain at the final follow-up (WMD, -0.58; 95% CI -0.93 to -0.23, p = 0.001; 327 vs. 268 patients). However the cervical group also developed a higher incidence of overall adjacent segment disease (ASD, including distal ASD and proximal ASD) (RR, 1.87; 95% CI 1.27 to 2.76, p = 0.001; 1079 vs. 860 patients), distal ASD (RR, 2.18; 95% CI 1.36 to 3.51, p = 0.001; 642 vs. 555 patients), overall hardware failure (including hardware failure of LIV and hardware failure occurring at other instrumented vertebra) (RR, 1.48; 95% CI 1.02 to 2.15, p = 0.040; 614 vs. 451 patients), and hardware failure of LIV (RR, 1.89; 95% CI 1.21 to 2.95, p = 0.005; 380 vs. 339 patients). The operating time was reasonably shorter (WMD, -43.47; 95% CI -59.42 to -27.52, p < 0.001; 611 vs. 570 patients) and the estimated blood loss was lower (WMD, -143.77; 95% CI -185.90 to -101.63, p < 0.001; 721 vs. 740 patients) when the PCF construct did not cross the CTJ.

CONCLUSIONS

PCF construct crossing the CTJ was associated with a lower incidence of ASD and hardware failure but a higher incidence of wound-related complications and a small increase in qualitative neck pain, without difference in neck disability on the NDI. Based on the subgroup analysis for surgical techniques and indications, prophylactic crossing of the CTJ should be considered for patients with concurrent instability, ossification, deformity, or a combination of anterior approach surgeries as well. However, long-term follow-up outcomes and patient selection-related factors such as bone quality, frailty, and nutrition status should be addressed in further studies.