Necessity of Bony Fusion After Surgical Treatment of Metastatic Spine Tumors

Usage Trends and Safety Profile of Recombinant Human Bone Morphogenetic Protein-2 for Spinal Column Tumor Surgery: A National Matched Cohort Analysis

STUDY DESIGN

Retrospective Cohort Analysis.

OBJECTIVE

The purpose of this study is to investigate national rates of rhBMP-2 utilization in spinal tumor surgery and examine its association with postoperative complications, revisions, and carcinogenicity.

METHODS

All patients diagnosed with primary or metastatic spinal tumors with subsequent surgical intervention involving a spinal fusion procedure were identified in PearlDiver. Patients were 1:1 matched into 2 cohorts according to rhBMP-2 usage. Postoperative complications and revisions were examined at 1 month, 3 months, 6 months, and 1 year after fusion. New cancer incidence following spinal tumor surgery was assessed until 5 years postoperatively.

RESULTS

A total of 11,198 patients underwent fusion surgery after resection of spinal tumors between 2005 and 2020, with 909 cases reporting the use of rhBMP-2 (8.1%). An annualized analysis revealed that the proportion of spine tumor fusion procedures utilizing rhBMP-2 has been significantly decreasing (R2 = .859, P < .001), with the most recent annual utilization rate at 1.1%. At least 3 months after surgery, significantly increased incidences of surgical site (11.4% vs 3.3%, P = .03) and systemic infections (8.1% vs 1.6%, P = .02) were observed in patients who underwent fusion with rhBMP-2. Across all time points, no significant differences were observed in survival, implant removal, revision rates, or new cancer diagnoses.

CONCLUSION

This analysis demonstrated significantly declining national utilization rates. Spinal tumor cases utilizing rhBMP-2 sustained greater rates of surgical site and systemic infections. rhBMP-2 usage did not significantly reduce the risk of mortality, implant failure, or reoperation.

Posterior vertebral column resection as a safe procedure leading to solid bone fusion in metastatic epidural spinal cord compression

OBJECTIVE

Cancer is one of the leading causes of death and greatly decreases a patient's quality of life. Vertebral metastases often lead to epidural spinal cord compression (ESCC) requiring surgical therapy. It has previously been shown that in patients with metastatic ESCC (MESCC), a surgical intervention leads to an improved outcome. Although the treatment paradigms in spinal metastases have changed and separation surgery followed by stereotactic radiosurgery is considered the best strategy, there are still cases in which 360° decompression with stabilization is indicated. In these patients, a proper bone fusion should be the treatment goal to guarantee good clinical results in extended survival times through progressions in oncological therapies. The aim of this study was to examine the safety and feasibility of posterior vertebral column resection (pVCR) in everyday clinical practice, achievement of bone fusion, and midterm outcome in patients with MESCC.

METHODS

All patients treated with pVCR due to MESCC between 2013 and 2020 were enrolled in this observational single-center study. Demographics, outcome parameters, numeric rating scale (NRS) score, Frankel grade, and Karnofsky Performance Scale (KPS) score were evaluated. Radiological images routinely acquired during follow-up were reviewed and screened for the presence of bone fusion.

RESULTS

Sixty-six patients were treated by eight surgeons. The mean follow-up period was 549 ± 739 days. At baseline, the average age was 64.4 ± 10.9 years. Reported NRS scores (preoperative 6.2 ± 1.7 vs postoperative 3.4 ± 1.6) and segmental kyphosis as measured on sagittal CT images (preoperative 13.5° ± 8.6° vs postoperative 3.8° ± 5.4°) decreased significantly (p < 0.001). In only 2 patients (3%), the Frankel grade worsened postoperatively, whereas in 12 patients (18.2%) an improvement was documented. The KPS score remained constant during the observation period (preoperative 73.2% ± 18.2% vs 78.3% ± 18% at last follow-up). Bone fusion was observed in 26 patients (86.7%) receiving CT more than 100 days after the index surgery.

CONCLUSIONS

pVCR is a reliable surgical technique in daily clinical practice, which proves to be beneficial in terms of short- as well as midterm outcome, as judged by the KPS and NRS. The overall improvement in the Frankel grade shows patient safety. A bone fusion was observed regularly in oncological patients undergoing pVCR. The authors therefore conclude that pVCR is a safe, fast, and efficient strategy to achieve stability and pain relief by achievement of bone fusion in cancer patients.