Tissue-Sparing Posterior Cervical Fusion With Interfacet Cages: A Systematic Review of the Literature

Perioperative and safety outcomes following tissue-sparing posterior cervical fusion to revise a pseudarthrosis: A multicenter retrospective review of 150 cases

Background

Posterior cervical fusion (PCF) with lateral mass screws is a favorable treatment option to revise a symptomatic pseudarthrosis due to reliable rates of arthrodesis; however, this technique introduces elevated risk for wound infection and hospital readmission. A tissue-sparing PCF approach involving facet fixation instrumentation reduces the rates of postoperative complications while stabilizing the symptomatic level to achieve arthrodesis; however, these outcomes have been limited to small study cohorts from individual surgeons commonly with mixed indications for treatment.

Materials and Methods

One hundred and fifty cases were identified from a retrospective chart review performed by seven surgeons across six sites in the United States. All cases involved PCF revision for a pseudarthrosis at one or more levels from C3 to C7 following anterior cervical discectomy and fusion (ACDF). PCF was performed using a tissue-sparing technique with facet instrumentation. Cases involving additional supplemental fixation such as lateral mass screws, rods, wires, or other hardware were excluded. Demographics, operative notes, postoperative complications, hospital readmission, and subsequent surgical interventions were summarized as an entire cohort and according to the following risk factors: age, sex, number of levels revised, body mass index (BMI), and history of nicotine use.

Results

The average age of patients at the time of PCF revision was 55 ± 11 years and 63% were female. The average BMI was 29 ± 6 kg/m2 and 19% reported a history of nicotine use. Postoperative follow-up visits were available with a median of 68 days (interquartile range = 41-209 days) from revision PCF. There were 91 1-level, 49 2-level, 8 3-level, and 2 4±-level PCF revision cases. The mean operative duration was 52 ± 3 min with an estimated blood loss of 14 ± 1.5cc. Participants were discharged an average of 1 ± 0.05 days following surgery. Multilevel treatment resulted in longer procedure times (single = 45 min, multi = 59 min, P = 0.01) but did not impact estimated blood loss (P = 0.94). Total nights in the hospital increased by 0.2 nights with multilevel treatment (P = 0.01). Sex, age, nicotine history, and BMI had no effect on recorded perioperative outcomes. There was one instance of rehospitalization due to deep-vein thrombosis, one instance of persistent pseudarthrosis at the revised level treated with ACDF, and four instances of adjacent segment disease. In patients initially treated with multilevel ACDF, revisions occurred most commonly on the caudal level (48% of revised levels), followed by the cranial (43%), and least often in the middle level (9%).

Conclusions

This chart review of perioperative and safety outcomes provides evidence in support of tissue-sparing PCF with facet instrumentation as a treatment for symptomatic pseudarthrosis after ACDF. The most common locations requiring revision were the caudal and cranial levels. Operative duration and estimated blood loss were favorable when compared to open alternatives. There were no instances of postoperative wound infection, and the majority of patients were discharged the day following surgery.

Long-term outcomes in patients treated with tissue-sparing posterior cervical fusion to revise a 1-level pseudarthrosis following ACDF

STUDY DESIGN

Observational Study BACKGROUND: Symptomatic pseudarthrosis is one long-term complication in patients treated with anterior discectomy and fusion (ACDF). When revising a pseudarthrosis, a surgeon must decide to intervene posteriorly and/or anteriorly. Open posterior cervical fusion (PCF) is attractive for high rates of arthrodesis, however this technique introduces risks of added complications resulting from extensive soft tissue dissection. The purpose of this study was to assess long-term outcomes in patients undergoing tissue-sparing PCF with facet instrumentation to treat a single level pseudarthrosis.

METHODS

Forty-five subjects were recruited from six participating sites. All subjects had a history of ACDF that was subsequently revised with tissue-sparing PCF to treat symptomatic pseudarthrosis at one level. Long-term radiographic assessments included flexion and extension X-ray and multi-planar CT. Subjects additionally completed a patient satisfaction questionnaire. Radiographs were assessed by investigators and an independent core imaging lab to diagnose implant integrity and arthrodesis at the revised levels.

RESULTS

The revision procedure required a median 49 min to complete with an estimated blood loss of 10 cc. Subjects were discharged a median 1 day following treatment. There were no instances of hospital re-admission nor subsequent surgical interventions. Study follow-up assessments were performed a median 39 months from revision. Surgeons diagnosed complete fusion in 91 % of cases. The core imaging lab identified bridging bone across the revised segment in 80 % of cases. Range of motion was < 2° in 93 % of cases. Seventy-four percent of subjects reported being satisfied with their outcomes.

CONCLUSIONS

This study summarizes long-term radiographic outcomes in a cohort of patients receiving tissue-sparing PCF for the treatment of pseudarthrosis. Assessed years after revision, patients achieved rates of arthrodesis similar to open PCF without the soft tissue dissection responsible for perioperative morbidity and long-term soft tissue pain.

Current concepts of spondylosis and posterior spinal motion preservation for radiologists

Spinal fusion is performed to eliminate motion at a degenerated or unstable segment. However, this is associated with loss of motion at the fused levels and increased stress on adjacent levels. Motion-preserving implants have been designed in effort to mitigate the limitations of fusion. This review will focus on posterior spinal motion-preserving technologies. In the cervical spine, laminoplasty is a posterior motion-preserving procedure used in the management of myelopathy/cord compression. In the lumbar spine, motion-sparing systems include interspinous process devices (also referred to as interspinous process spacers or distraction devices), posterior dynamic stabilization devices (also referred to as pedicle screw/rod fixation-based systems), and posterior element replacement systems (also referred to as total facet replacement devices). Knowledge of the intended physiologic purpose, hardware utilized, and complications is important in the assessment of imaging in those who have undergone posterior motion preservation procedures.

Multilevel, Percutaneous Posterior Cervical Interfacet Distraction and Fusion for Cervical Spondylotic Radiculopathy: Clinical and Radiographic Outcomes

STUDY DESIGN

Retrospective review of patients who underwent multilevel posterior cervical interfacet distraction and fusion (PCIDF) using cages for cervical spondylotic radiculopathy (CSR).

OBJECTIVE

To determine clinical and radiographic outcomes following multilevel PCIDF.

SUMMARY OF BACKGROUND DATA

Anterior cervical discectomy and fusion has long been the standard of treatment for CSR. Advancements in surgery have employed minimally invasive techniques such as endoscopic discectomy, foraminotomy, and PCIDF. Studies on single-level PCIDF have reported good clinical outcomes, short hospital stays, and rare complications, but its application in multilevel disease is still evolving.

METHODS

Patients with CSR and confirmed radiologic evidence of multilevel foraminal stenosis without central canal stenosis were reviewed. Two-year outcomes of multilevel PCIDF included Neck Disability Index, neck and arm Visual Analogue Scale (VAS), radiographic cervical alignment parameters, evidence of fusion, and incidence of adjacent segment degeneration were compared at different time points.

RESULTS

Thirty patients (mean age 54.6 ± 8.3) were included in the study with an average of 3.4 ± 0.8 levels treated. Mean surgical duration and intraoperative blood loss was 143.2 ± 69.7 minutes and 27.7 ± 28.7 mL, respectively, with an average length of stay at 1.8 ± 1.5 days. Neck Disability Index, VAS-neck, and VAS-arm all significantly improved at 2 weeks (P < 0.001) and was maintained until 2 years postoperatively. A significant decrease in segmental and C2-C7 lordosis, with a corresponding increase in sagittal vertical axis, was observed at 3 months postoperatively (P < 0.001) but did not deteriorate further on subsequent visits. Successful fusion was achieved in 90% of patients after 2 years. There was a 13.3% incidence of adjacent segment degeneration in the study cohort and one perioperative complication (3.3%).

CONCLUSION

Our study suggests that multilevel PCIDF is safe and effective for CSR caused by foraminal stenosis. However, its potential to cause kyphosis and clinical impact on global sagittal alignment requires further scrutiny and long-term evaluation.Level of Evidence: 4.