Ultrasonic Bone Scalpel in Anterior Cervical Discectomy and Fusion Enhances Outcomes and Foraminal Decompression in Cervical Radiculopathy: A Retrospective Cohort Study

Abstract

Study design retrospective cohort study objective: This study compared the safety and efficacy of ultrasonic bone scalpel-assisted direct decompression versus conventional direct decompression (using high-speed drills and Kerrison rongeurs) in anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy with foraminal bone stenosis. This retrospective cohort study included 94 patients who underwent cervical foraminal stenosis surgery from 2019 to 2022. Group A (n=48) received traditional direct decompression using a high-speed drill and Kerrison rongeur, while Group B (n=46) underwent direct decompression using a combination of drilling and ultrasonic bone scalpel. Clinical outcomes were assessed using Visual Analog Scale (VAS) for pain, Neck Disability Index (NDI) for functional disability, and smallest oblique sagittal area (SOSA) of the neural foramen on CT scans to evaluate foraminal enlargement.

Results: Patients in Group B demonstrated significantly greater improvements in VAS and NDI scores (p<0.01), with a larger mean SOSA (73.85 mm² vs 50.00 mm²) compared to Group A. Additionally, Group B showed a reduction in blood loss and shorter operative time. No significant differences in complication rates, including dural tears or nerve root injuries, were found between the two groups.

Conclusion: The ultrasonic bone scalpel-assisted decompression technique offers significant advantages over traditional methods in terms of surgical outcomes, including better pain relief, functional recovery, and foraminal enlargement, while maintaining comparable safety profiles.

Keywords: ACDF; anterior cervical discectomy and fusion; foraminotomy; smallest oblique sagittal area; ultrasonic bone scalpel.

Figure 1

The square-headed spatula-shaped ultrasonic bone scalpel used in the present surgery.

Figure 2

Schematic diagram (A and B) and intraoperative photograph (C–J) of the application of ultrasonic osteotome in foraminotomy. Cranial direction is to the left. (C) After complete resection of the disc, the margin of the uncinate joint (small black arrow) is exposed, (A–D) the inner wall of the uncinate process is trimmed with a diamond bit (small black arrow) to thin the bone into a thin shell, (E) removal is stopped when cancellous bone hemorrhage occurs. (B–F) Osteotomy was performed at the posterior edge of the uncinate process with square-headed spatula-shaped ultrasonic bone scalpel as shown in Figure 1, which was inserted into the intervertebral foramen to further remove hyperplastic osteophytes behind the uncinate process, (G) posterior longitudinal ligament was resected using nerve hooks (small black arrow), (H) dura mater was exposed, (I) bone hyperplasia was further resected with ultrasonic bone scalpel, and (J) nerve hook (small black arrow) was subsequently used to verify the patency of the intervertebral foramen, and foraminotomy was completed when the nerve hook could easily and unobstructed access to the anterior foramen and to the nerve root outlet.

Figure 3

(A) The mean trend chart of preoperative and postoperative neck VAS; (B) The mean trend chart of preoperative and postoperative arm VAS; (C) The mean trend chart and that of preoperative and postoperative NDI; Group A patients who underwent foraminotomy using conventional tools; Group B patients who underwent foraminal decompression by ultrasonic bone scalpel. *means P value<0.05; **means P<0.01.

Figure 4

A case of cervical 5/6 bony foraminal stenosis was observed. Preoperative X-rays and CT scans (A–E) revealed stenosis of the right intervertebral foramen at the C5/6 level, which was caused by hypertrophy of the uncinate process. Postoperative X-rays and CT scans (F–H) demonstrated incomplete removal of the right uncinate process, complete elimination of hypertrophic osteophytes, and a noticeable enlargement of the right neural foramen.