Comparative Study of Ultrasonic Bone Scalpel and Drill in Keyhole Spinal Surgery: Efficiency, Safety, and Learning Curve Analysis

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However, the optimal surgical tool for keyhole spinal procedures—ultrasonic bone scalpel or traditional drill—remains debated. This study aimed to compare these tools regarding operative efficiency, learning curves, clinical outcomes, and complication rates. Methods A prospective cohort study was conducted involving 72 patients with cervical radiculopathy who underwent keyhole spinal surgery at a single tertiary care center. Patients were assigned to the ultrasonic bone scalpel group (n = 36) or the drill group (n = 36). Data on operative time, intraoperative blood loss, clinical outcomes (VAS, JOA scores), complications, and radiological assessments (NR-SCW distance, STE area) were collected preoperatively and at 3 and 6 months postoperatively. Statistical analyses included independent t-tests, repeated measures ANOVA, and CUSUM analysis. Results The ultrasonic bone scalpel group demonstrated significantly shorter operative times (95.72 ± 8.32 vs. 121.97 ± 11.53 minutes, p < 0.001), lower intraoperative blood loss (41.81 ± 2.46 vs. 49.58 ± 2.57 mL, p < 0.001), and smaller postoperative soft tissue edema areas (19.09 ± 6.84 mm² vs. 33.66 ± 15.91 mm², p < 0.001) compared to the drill group. Pain relief (VAS scores) and functional recovery (JOA scores) were superior in the ultrasonic bone scalpel group at both 3 and 6 months. The learning curve analysis revealed that proficiency was achieved after 10 cases in the ultrasonic bone scalpel group, compared to 25 cases in the drill group. No significant differences in complication rates or recurrence were observed between groups. Conclusion The ultrasonic bone scalpel offers significant advantages in operative efficiency, soft tissue preservation, and clinical outcomes while providing a shorter learning curve. These findings support its broader adoption in minimally invasive spinal surgery for cervical radiculopathy. Ultrasonic Bone Scalpel Cervical Radiculopathy Keyhole Spinal Surgery Minimally Invasive Spine Surgery Learning Curve Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Minimally invasive spinal surgery has revolutionized the treatment of cervical radiculopathy by reducing tissue trauma and promoting faster recovery compared to conventional open procedures( 1 ). Among these techniques, the keyhole approach has gained significant traction for its ability to achieve effective nerve decompression while minimizing damage to surrounding structures(2)( 3 ). However, the choice of surgical tools within the keyhole approach remains a matter of debate, particularly concerning the traditional drill (burr) and the ultrasonic bone scalpel. The burr, a long-standing tool in spinal surgery, is effective for bone resection but is associated with thermal damage, increased risk of dural tears, and higher rates of intraoperative nerve injury( 4 )( 5 ). In contrast, the ultrasonic bone scalpel, with its selective tissue-cutting capability and reduced heat generation, offers a promising alternative for enhancing nerve safety during minimally invasive procedures( 6 ). Despite its theoretical advantages, the evidence directly comparing the ultrasonic bone scalpel with the burr in terms of clinical outcomes, learning curves, and postoperative complications remains sparse. Early research on ultrasonic bone scalpels has highlighted their potential to lower postoperative pain and soft tissue edema while shortening operative times( 7 ). However, these findings are largely derived from non-spinal applications, leaving a gap in the literature regarding their role in cervical keyhole surgery. Moreover, understanding the learning curve associated with these tools is crucial for their widespread adoption in clinical practice( 8 )( 9 ). This study aims to compare the ultrasonic bone scalpel and burr in keyhole spinal surgery for cervical radiculopathy. Specifically, we evaluate their impact on operative efficiency, learning curves, and clinical outcomes, including pain relief, functional recovery, and complication rates. By addressing these aspects, we aim to provide evidence-based guidance for optimizing tool selection in minimally invasive spinal procedures. Methods Study Design and Patient Selection This prospective cohort study was conducted between January 2023 and December 2024 at Honghui Hospital, Xi'an Jiaotong University. A total of 72 patients diagnosed with cervical radiculopathy and undergoing keyhole spinal surgery were included. Patients were divided into two groups based on the surgical instrument used: the Ultrasonic Bone Scalpel group (n = 36) and the Drill group (n = 36). Inclusion criteria consisted of adults aged 18–75 years, diagnosed with cervical radiculopathy confirmed by MRI and clinical symptoms, with spinal segments limited to C4-C5, C5-C6, C6-C7, or C7-T1. Patients were included if they exhibited severe pain (VAS ≥ 6) or functional impairment requiring surgical intervention. Exclusion criteria included a history of prior cervical spine surgery, the presence of systemic diseases (e.g., severe osteoporosis, malignancy, or infection), and inability to complete follow-up evaluations. Surgical Techniques All surgeries were performed by two experienced spinal surgeons using a standardized keyhole technique under general anesthesia. In the Ultrasonic bone scalpel group, a ultrasonic bone scalpel (SMTP, CHN) was utilized for decompression. Operating at a frequency of 25–30 kHz, this device enabled precise bone cutting while minimizing soft tissue and nerve root damage. It was specifically used for osteophyte removal and nerve decompression. In the Drill group, a Midas Rex® high-speed drill (Medtronic, USA) was employed to perform similar procedures, including osteophyte removal and nerve decompression. Special care was taken to control heat generation and avoid nerve root injury during the procedure. Data Collection Clinical and radiological data were collected preoperatively and at 3 and 6 months postoperatively, focusing on clinical outcomes, surgical metrics, and radiological assessments. Clinical outcomes included VAS scores (Visual Analog Scale) for pain evaluation, JOA scores (Japanese Orthopaedic Association) for functional recovery assessment, and complication rates (e.g., intraoperative nerve root injuries, dural tears, cerebrospinal fluid leaks, and infections). Surgical metrics comprised operative time, recorded from skin incision to closure, and intraoperative blood loss, measured using suction canisters and sponges. Learning curve analysis was performed using the Cumulative Sum (CUSUM) method based on operative time. Radiological assessments were conducted using ImageJ software to analyze pre- and postoperative MRI scans, measuring the Nerve Root to Spinal Canal Wall Distance (NR-SCW, mm), Soft Tissue Edema Area (STE Area, mm²), and lesion volume (cm³). Statistical Analysis All statistical analyses were performed using SPSS (version 26.0; IBM, USA) and GraphPad Prism (version 9.0; GraphPad Software, USA). Statistical significance was set at p < 0.05. Continuous variables, such as VAS scores, JOA scores, and operative time, were expressed as mean ± standard deviation (SD) and compared using independent t-tests or Mann-Whitney U tests as appropriate. Categorical variables, such as complication rates, were presented as frequencies (%) and compared using the Chi-square test or Fisher’s exact test. Changes in VAS and JOA scores over time (baseline, 3 months, and 6 months) were evaluated using repeated measures ANOVA. Learning curves were assessed using CUSUM analysis of operative time, identifying the number of cases required for each group to achieve proficiency. Results Baseline Characteristics A total of 72 patients were included in the study, with 36 patients in the Ultrasonic Bone Scalpel group and 36 in the Drill group. Baseline demographic and clinical characteristics, such as age, gender distribution, surgical segments, and preoperative VAS and JOA scores, were comparable between the two groups, with no statistically significant differences (all p > 0.05). Detailed baseline characteristics are provided in Table 1 . Table 1 Baseline Characteristics of Patients in the Ultrasonic Scalpel and Drill Groups Variables N (%) Mean (± SD) Overall n = 72 Drill n = 36 Ultrasonic Scalpel n = 36 p value Age (years) 56.68 ± 4.49 56.39 ± 5.07 56.97 ± 3.83 0.68 Gender 0.23 male 44 (61.11%) 25(69.44%) 19 (52.78%) female 28 (38.89%) 11(30.56%) 17 (47.22%) Segment 0.46 C4-C5 10 (13.89%) 6(16.67%) 4 (11.11%) C5-C6 30 (41.67%) 14(38.89%) 16 (44.44%) C6-C7 14 (19.44%) 9(25.00%) 5 (13.89%) C7-T1 18 (25.00%) 7(19.44%) 11 (30.56%) JOA 8.57 ± 1.29 8.53 ± 1.32 8.61 ± 1.25 0.59 VAS 6.24 ± 0.87 6.19 ± 0.89 6.28 ± 0.85 0.46 Operation time(min) 108.85 ± 11.53 121.97 ± 11.53 95.72 ± 8.32 0.00* Blood loss (ml) 45.69 ± 2.52 49.58 ± 2.57 41.81 ± 2.46 0.00* Intraoperative Nerve Root Injury Y 1 (1.39%) 1 (2.78%) 0 (0.00%) 1.00 N 71 (98.61%) 35 (97.22%) 36 (100.0%) Dural Tear Y 2 (2.78%) 2 (5.56%) 0 (0.00%) 0.47 N 70 (97.22%) 34 (94.44%) 36 (100.0%) Postoperative VAS 4.17 ± 1.11 4.55 ± 1.20 3.80 ± 0.90 0.00* Postoperative VAS (3 months) 1.55 ± 0.78 1.92 ± 0.77 1.18 ± 0.22 0.00* Postoperative VAS (6 months) 1.23 ± 0.75 1.46 ± 1.00 1.00 ± 0.00 0.00* Postoperative JOA 8.35 ± 1.06 8.10 ± 1.00 8.60 ± 1.10 0.08 Postoperative JOA (3 months) 10.91 ± 1.21 10.69 ± 1.17 11.12 ± 1.24 0.07 Postoperative JOA (6 months) 11.11 ± 0.85 10.97 ± 1.17 11.25 ± 0.44 0.07 Length of Hospital Stay 5.25 ± 1.21 5.47 ± 1.25 5.03 ± 1.16 0.15 Pre-op NR-SCW Distance (mm) 3.23 ± 1.06 3.14 ± 1.08 3.33 ± 1.03 0.47 Post-op NR-SCW Distance (mm) 5.85 ± 1.47 5.72 ± 1.54 5.98 ± 1.40 0.59 Pre-op STE Area (mm²) 63.22 ± 20.31 62.08 ± 20.48 64.35 ± 19.97 0.62 Post-op STE Area (mm²) 26.38 ± 12.65 33.66 ± 15.91 19.09 ± 6.84 0.00* Pre-OP Lesion Volume (cm³) 2.95 ± 1.15 2.90 ± 1.15 3.00 ± 1.14 0.71 Post-OP Lesion Volume (cm³) 1.81 ± 0.88 1.82 ± 0.86 1.79 ± 0.89 0.84 Recurrence 1.00 Y 7 (9.72%) 4 (11.11%) 3 (8.33%) N 65 (90.28%) 32 (88.89%) 33 (91.67%) Abbereviation: Pre-op NR-SCW Distance (mm): Preoperative MRI: Nerve Root to Spinal Canal Wall Distance (mm) Post-op NR-SCW Distance (mm): Postoperative MRI: Nerve Root to Spinal Canal Wall Distance (mm) Pre-op STE Area (mm²): Preoperative MRI: Soft Tissue Edema Area (mm 2 ) Post-op STE Area (mm²): Postoperative MRI: Soft Tissue Edema Area (mm 2 ) Pre-OP Lesion Volume (cm³): Preoperative MRI: Lesion Volume (cm 3 ) Post-OP Lesion Volume (cm³): Postoperative MRI: Lesion Volume (cm 3 ) Continuous variables (e.g., age, BMI, NR-SCD, STE-Area, Lesion-Vol) are presented as mean ± standard deviation (Mean ± SD) and compared using an independent samples t-test or Mann-Whitney U test. Categorical variables (e.g., sex, NSAIDs usage) are shown as frequency and percentage, with group comparisons performed using Chi-square or Fisher’s exact test. Table 2 Repeated Measures ANOVA Results Score Type F Value Num DF Den DF Pr > F VAS 149.0112 1 71 0.0000 JOA 115.4413 1 71 0.0000 Abbreviations : DF: Degrees of Freedom; Pr > F: Probability of observing a test statistic as extreme as, or more extreme than, the value observed, under the null hypothesis. Data are presented as Mean ± Standard Deviation (SD). Group differences were analyzed using Repeated Measures ANOVA with statistical significance set at p < 0.05. Repeated Measures ANOVA showed significant differences in VAS and JOA scores at postoperative 3 and 6 months (p < 0.001). Degrees of freedom for each score are 1 (Num DF) and 71 (Den DF), respectively. Surgical Metrics The Ultrasonic Bone Scalpel group demonstrated significantly better surgical efficiency compared to the Drill group. Operative time was notably shorter in the Ultrasonic Bone Scalpel group (95.72 ± 8.32 minutes) compared to the Drill group (121.97 ± 11.53 minutes, p < 0.001). The CUSUM learning curve analysis revealed that proficiency was achieved after 10 cases in the Ultrasonic Bone Scalpel group, whereas the Drill group required 25 cases to reach a similar level (Fig. 2 ). Intraoperative blood loss was also significantly lower in the Ultrasonic Bone Scalpel group (41.81 ± 2.46 mL vs. 49.58 ± 2.57 mL, p < 0.001). In terms of intraoperative complications, the incidence of nerve root injury was 0% in the Ultrasonic Bone Scalpel group compared to 2.78% in the Drill group (p = 1.00). Similarly, no dural tears were observed in the Ultrasonic Bone Scalpel group, while the Drill group reported a rate of 5.56% (p = 0.47). (Figure.3) Clinical Outcomes The Ultrasonic Bone Scalpel group showed superior pain relief and functional recovery compared to the Drill group. At three months postoperatively, VAS scores were significantly lower in the Ultrasonic Bone Scalpel group (1.18 ± 0.22) compared to the Drill group (1.92 ± 0.77, p < 0.001), and this trend was maintained at six months (1.00 ± 0.00 vs. 1.46 ± 1.00, p < 0.001). Repeated measures ANOVA confirmed a significant interaction between time and group, demonstrating greater pain relief in the Ultrasonic Bone Scalpel group (F = 149.01, p < 0.001, Fig. 5 ). JOA scores also improved significantly in both groups. At three months, the Ultrasonic Bone Scalpel group achieved slightly higher scores compared to the Drill group (11.12 ± 1.24 vs. 10.69 ± 1.17, p = 0.07). At six months, the Ultrasonic Bone Scalpel group showed superior functional recovery (11.25 ± 0.44 vs. 10.97 ± 1.17, p = 0.07). Repeated measures ANOVA indicated significant improvement over time (F = 115.44, p < 0.001), although the interaction effect between group and time did not reach statistical significance (p = 0.07). (Table.2) Radiological Outcomes Radiological evaluations demonstrated similar patterns of improvement in both groups, with the Ultrasonic Bone Scalpel group exhibiting slightly better results. Preoperative NR-SCW distances were comparable between the two groups (3.33 ± 1.03 mm vs. 3.14 ± 1.08 mm, p = 0.47). Postoperatively, both groups achieved significant increases in NR-SCW distance, with the Ultrasonic Bone Scalpel group showing slightly greater improvements (5.98 ± 1.40 mm vs. 5.72 ± 1.54 mm, p = 0.59). Postoperative soft tissue edema area was significantly smaller in the Ultrasonic Bone Scalpel group (19.09 ± 6.84 mm²) compared to the Drill group (33.66 ± 15.91 mm², p < 0.001), reflecting reduced tissue damage and better soft tissue preservation. Both groups achieved similar reductions in lesion volume postoperatively (1.79 ± 0.89 cm³ vs. 1.82 ± 0.86 cm³, p = 0.84). (Figure.1) Interaction Effects Subgroup analysis by surgical segment (C4-C5, C5-C6, C6-C7, C7-T1) did not reveal any statistically significant differences in VAS and JOA scores between segments (p > 0.05 for all interaction effects). However, the Ultrasonic Bone Scalpel group consistently demonstrated better outcomes across all segments (Table 3) (Fig. 4 ). Table 3: Interaction Effects Analysis by Surgical Segment Effect Sum of Squares DF F Value Pr > F Segment 0.543272 3 0.860508 0.4621 Group 1.042437 1 4.953464 0.0269 Score_Type 9603.793347 1 45635.4203 0.0000 Time 0.105549 1 0.501550 0.4795 Segment:Group 0.014057 3 0.022266 0.9955 Segment:Score_Type 0.135253 3 0.214233 0.8865 Group:Score_Type 118.484240 1 563.0148 1.35e-66 Segment:Time 1.631791 3 2.584655 0.0537 Group:Time 0.807625 1 3.837683 0.0512 Score_Type:Time 54.496561 1 258.9574 9.84e-41 Segment:Group:Score_Type 0.722107 3 1.143773 0.3319 Segment:Group:Time 1.955320 3 3.097104 0.0274 Segment:Score_Type:Time 0.535400 3 0.848040 0.4687 Group:Score_Type:Time 0.111308 1 0.528914 0.4677 Segment:Group:Score_Type:Time 0.546519 3 0.865651 0.4594 Residual 53.874185 256 - - Abbreviations: DF: Degrees of Freedom; Pr > F: Probability of observing a test statistic as extreme as, or more extreme than, the value observed, under the null hypothesis. Data are presented as Mean ± Standard Deviation (SD). Group differences were analyzed using Repeated Measures ANOVA with statistical significance set at p < 0.05. Analysis of variance (ANOVA) was conducted to assess interaction effects between surgical segment, treatment group, score type, and time. Each main effect and interaction term was tested, with p-values indicating statistical significance at conventional levels (e.g., p < 0.05). Complications and Recurrence The overall complication rates were lower in the Ultrasonic Bone Scalpel group compared to the Drill group, but this difference was not statistically significant (p = 1.00, p = 0.47). Recurrence rates were similarly low in both groups, with no significant differences observed (8.33% in the Ultrasonic Bone Scalpel group vs. 11.11% in the Drill group, p = 1.00). Discussion This study provides a comprehensive comparison between the ultrasonic bone scalpel and the traditional drill in keyhole spinal surgery for cervical radiculopathy, highlighting significant advantages in operative efficiency, soft tissue preservation, clinical outcomes, and surgeon learning curves. By integrating our findings with prior research, we provide evidence-based insights into the superiority of the ultrasonic bone scalpel and the potential reasons for its improved performance. Operative Efficiency and Learning Curve One of the most prominent findings of this study was the significantly shorter operative time in the ultrasonic bone scalpel group compared to the drill group. This can be attributed to the device’s ability to perform precise bone cutting without requiring additional steps to manage heat damage or minimize risks to soft tissues. Similar results have been reported in other spinal surgeries where ultrasonic devices were associated with reduced operative times due to their efficiency in cutting hard tissues while sparing soft structures(10)( 11 ). In addition, our learning curve analysis demonstrated that surgeons reached proficiency after 10 cases with the ultrasonic bone scalpel, whereas 25 cases were required for the drill group. This result aligns with prior studies indicating that the intuitive handling of ultrasonic bone scalpels and their selective tissue-cutting properties reduce the cognitive and technical demands on surgeons during the learning phase ( 6 ). Furthermore, a shorter learning curve is clinically significant as it facilitates the adoption of new techniques in minimally invasive surgery, ultimately improving patient outcomes and reducing the potential for surgeon error during the early phase of skill acquisition( 7 ). Soft Tissue Preservation Another critical finding was the significantly smaller postoperative soft tissue edema area in the ultrasonic bone scalpel group, suggesting superior preservation of surrounding tissues. The ultrasonic bone scalpel’s mechanism, which combines high-frequency vibration with minimal heat generation, allows selective cutting of calcified structures while sparing elastic soft tissues such as the dura and nerve roots( 12 )( 11 ). In contrast, traditional drills often generate excessive heat, which can cause collateral tissue damage and local inflammation, potentially contributing to larger edema areas( 13 ). Previous studies in general surgery and orthopedic applications of ultrasonic devices have also reported similar benefits, including reduced soft tissue trauma and postoperative inflammation( 14 ). In our study, this tissue-preserving effect of the ultrasonic bone scalpel likely contributed to improved pain relief and faster functional recovery, further supporting its advantages in minimally invasive spinal procedures. Clinical Outcomes Clinical outcomes were another area where the ultrasonic bone scalpel group demonstrated superior results. Patients in this group reported significantly lower VAS scores at 3 and 6 months postoperatively, indicating better pain control compared to the drill group. Additionally, improvements in JOA scores were more pronounced in the ultrasonic bone scalpel group, reflecting better functional recovery. These findings are consistent with earlier studies in spinal surgery, where reduced tissue trauma from ultrasonic devices was linked to decreased postoperative pain and quicker neurological recovery( 15 ). The mechanism underlying these superior outcomes is likely multifactorial. First, the reduced intraoperative trauma observed in the ultrasonic bone scalpel group minimizes the inflammatory cascade and associated pain. Second, the smaller soft tissue edema area in this group decreases postoperative nerve compression, promoting better recovery of neurological function. Finally, the more efficient surgical process associated with the ultrasonic bone scalpel may reduce systemic stress during surgery, indirectly contributing to improved recovery trajectories( 16 ). Safety Profile While both groups demonstrated low complication rates, the ultrasonic bone scalpel group had no cases of dural tears or nerve root injuries. Although this difference was not statistically significant, the trend is clinically relevant. Traditional drills are associated with higher risks of thermal and mechanical damage, which can lead to complications such as dural tears or nerve root irritation( 17 ). The ultrasonic bone scalpel, on the other hand, operates with minimal thermal spread and controlled cutting, providing an inherent safety advantage( 18 ). These findings align with reports from other studies highlighting the safety profile of ultrasonic devices in delicate surgical fields, including neurosurgery and otolaryngology( 19 ). Comparison with Prior Research Our findings align with and extend those of earlier studies on the ultrasonic bone scalpel. Previous research in general surgery, orthopedic applications, and some spinal procedures has demonstrated the advantages of ultrasonic devices in reducing operative times, minimizing tissue trauma, and improving clinical outcomes( 9 )( 20 ). However, few studies have directly compared the ultrasonic bone scalpel with traditional drills in keyhole spinal surgery. By filling this gap, our study provides specific evidence supporting the ultrasonic bone scalpel’s role in cervical radiculopathy treatment, highlighting its unique benefits in a minimally invasive context. One notable difference from prior research is the emphasis on learning curves. While previous studies have primarily focused on patient outcomes, our inclusion of surgeon learning curve analysis provides a broader perspective on the device’s clinical utility. This distinction underscores the importance of integrating both patient and surgeon outcomes when evaluating new surgical technologies. Limitations and Future Directions Despite its strengths, this study has limitations. The single-center design and relatively small sample size may limit the generalizability of our findings. Additionally, the follow-up period was restricted to 6 months, which may not capture long-term outcomes such as recurrence rates or late complications. Future multicenter studies with larger cohorts and extended follow-up periods are necessary to validate our findings and provide more comprehensive insights into the long-term benefits of ultrasonic devices in spinal surgery. Further research could also explore cost-effectiveness and patient-reported outcomes, which were beyond the scope of this study. Finally, investigating the performance of the ultrasonic bone scalpel in more complex spinal procedures or other regions of the spine could expand its clinical applications and establish its broader role in minimally invasive surgery. Conclusion This study demonstrates that the ultrasonic bone scalpel is a safer, more efficient, and clinically effective alternative to the traditional drill in keyhole spinal surgery for cervical radiculopathy. By reducing operative time, minimizing tissue trauma, and improving both pain relief and functional recovery, the ultrasonic bone scalpel offers significant benefits for patients and surgeons alike. Future research should focus on validating these findings in larger populations, exploring cost-effectiveness, and assessing long-term outcomes to support the widespread adoption of ultrasonic devices in spinal surgery. Abbreviations Pre-op NR-SCW Distance (mm) Preoperative MRI:Nerve Root to Spinal Canal Wall Distance (mm) Post-op NR-SCW Distance (mm) Postoperative MRI:Nerve Root to Spinal Canal Wall Distance (mm) Pre-op STE Area (mm²) Preoperative MRI:Soft Tissue Edema Area (mm²) Post-op STE Area (mm²) Postoperative MRI:Soft Tissue Edema Area (mm²) Pre-op Lesion Volume (cm³) Preoperative MRI:Lesion Volume (cm³) Post-op Lesion Volume (cm³) Postoperative MRI:Lesion Volume (cm³) Declarations Acknowledgements None. Disclosure of Funding None. Availability of data and materials The datasets used during the current study are available from the corresponding author on reasonable request. Ethics approval and consent to participate The study was conducted according to the guidelines of the Declaration of Helsinki. The need for approval was waived by the Ethical Committee of Honghui Hospital, Xi'an Jiaotong University for this retrospective study. Informed consent was obtained from all subjects involved in the study. Consent for publication Not applicable. Competing interests The authors declare no competing interests. References K J, Y L, Dh H, V K, S S, Js K. Minimally invasive endoscopy in spine surgery: where are we now? PubMed [Internet]. [cited 2024 Dec 29]; Available from: https://pubmed.ncbi.nlm.nih.gov/36856868/ Kc M, T K, M M, M W, So E. Keyhole approaches to intradural pathologies. PubMed [Internet]. [cited 2024 Dec 29]; Available from: https://pubmed.ncbi.nlm.nih.gov/28760029/ J L, J M, X F, X T, L S. 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Potential risk of thermal damage to cervical nerve roots by a high-speed drill. PubMed [Internet]. [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/19880905/ Cp C, Ps da SR, Flf M, Mm F, M de FF. Hemostasis with the Ultrasonic Scalpel. PubMed [Internet]. [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/30626994/ Jm S, J N, Rv H, Ne W, A J. Ultrasonic bone removal from the ossicular chain affects cochlear structure and function. PubMed [Internet]. 2021 [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/33810814/ Y C, Z C, X Y, R S, W H. Use of Ultrasonic Device in Cervical and Thoracic Laminectomy: a Retrospective Comparative Study and Technical Note. PubMed [Internet]. 2018 [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/29507350/ Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7011869","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":485425244,"identity":"481554ec-4490-4181-af68-b140c8d4e46c","order_by":0,"name":"Kaiyuan Lin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/UlEQVRIie3RMUvEMBTA8VcqcXk1a0LK+RUKDnJw6FfpceAtfoAODimBuDm3g1/DOSXgVLxVOAe76OKQW8RJ7F23g0sdBfNfAiE/Ho8AhEJ/MAaR3J4pgah8zYsZUip/R5BArDLXXqW8MmNkCAGONa+1nWUy9xN+a7XAmxc8EaUU2K4wAxO5zfVhInDek8c3JGkjz7BY43ksY14/HCYT2BJikbC5XGC7xqk0JE58hHY9+R6ITfQTZib3E8H6KYnekbKstRknvOrU9P5uRxS4doG8apR3F7Zads8fn3ZyWi3fv/Li4pJS1biNh/Qdsb2L4XN9xW7sRSgUCv3zfgDwWFFxjLGELQAAAABJRU5ErkJggg==","orcid":"","institution":"Honghui Hospital, Xi'an Jiaotong University","correspondingAuthor":true,"prefix":"","firstName":"Kaiyuan","middleName":"","lastName":"Lin","suffix":""},{"id":485425245,"identity":"c1b34bee-516f-4a7b-9697-7cc8f4f2907c","order_by":1,"name":"JunSong Yang","email":"","orcid":"","institution":"Honghui Hospital, Xi'an Jiaotong University","correspondingAuthor":false,"prefix":"","firstName":"JunSong","middleName":"","lastName":"Yang","suffix":""}],"badges":[],"createdAt":"2025-06-30 14:53:22","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7011869/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7011869/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":86777439,"identity":"a70e9515-c396-467b-a99d-115817e8a1b5","added_by":"auto","created_at":"2025-07-15 12:50:10","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":62850,"visible":true,"origin":"","legend":"\u003cp\u003eMRI-based Measurement Techniques for Lesion Volume, Nerve Root to Spinal Canal Wall Distance, and Soft Tissue Edema Area\u003c/p\u003e\n\u003cp\u003e(A,B) Illustrations of lesion volume calculation using ImageJ software on MRI scans, where lesions are outlined and accumulated across levels to determine the total Lesion Volume. (C) Demonstration of the Nerve Root to Spinal Canal Wall Distance (NR-SCW Distance) measurement on MRI, with preoperative and postoperative distances highlighted. (D) Soft Tissue Edema Area (STE Area) representation on MRI, showing the delineation of edematous areas both preoperatively and postoperatively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePre-op NR-SCW Distance (mm):\u003c/strong\u003ePreoperative MRI: Nerve Root to Spinal Canal Wall Distance (mm)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePost-op NR-SCW Distance (mm):\u003c/strong\u003ePostoperative MRI: Nerve Root to Spinal Canal Wall Distance (mm)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePre-op STE Area (mm²):\u003c/strong\u003ePreoperative MRI: Soft Tissue Edema Area (mm²)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePost-op STE Area (mm²):\u003c/strong\u003ePostoperative MRI: Soft Tissue Edema Area (mm²)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePre-op Lesion Volume (cm³):\u003c/strong\u003ePreoperative MRI: Lesion Volume (cm³)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePost-op Lesion Volume (cm³):\u003c/strong\u003ePostoperative MRI: Lesion Volume (cm³)\u003c/p\u003e","description":"","filename":"figure.1.tiff.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7011869/v1/376dcdf48b6c0bff1a2d992d.jpg"},{"id":86778609,"identity":"eb1865c6-17f1-4659-ba4a-f28e110085ca","added_by":"auto","created_at":"2025-07-15 12:58:10","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":647057,"visible":true,"origin":"","legend":"\u003cp\u003eCUSUM Learning Curve: Scalpel vs Drill (Operation Time).\u003c/p\u003e\n\u003cp\u003eThis figure illustrates the cumulative sum (CUSUM) learning curves for operation time in the Scalpel Group (Ultrasonic Scalpel) and the Drill Group (Burr). The blue line shows the Scalpel Group’s learning curve, while the green dashed line represents the Drill Group. The red dashed line indicates the baseline mean operation time.\u003c/p\u003e","description":"","filename":"figure.2.png","url":"https://assets-eu.researchsquare.com/files/rs-7011869/v1/753256d38ca57b74d378a10e.png"},{"id":86778930,"identity":"914071c4-f527-41e9-87e4-bf10a7f21ebb","added_by":"auto","created_at":"2025-07-15 13:06:10","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":416518,"visible":true,"origin":"","legend":"\u003cp\u003eComplication Rate by Surgery Number: Scalpel vs Drill.\u003c/p\u003e\n\u003cp\u003eThis figure displays the intraoperative nerve root injury rate across surgery numbers for both the Scalpel Group (Ultrasonic Scalpel) and the Drill Group (Burr). The blue line represents the Scalpel Group, and the green dashed line represents the Drill Group.\u003c/p\u003e","description":"","filename":"figure.3.png","url":"https://assets-eu.researchsquare.com/files/rs-7011869/v1/22dcb3275d6b7c9f5568ff21.png"},{"id":86778605,"identity":"0ee2d945-3cb1-4c81-87f9-8858241e60ac","added_by":"auto","created_at":"2025-07-15 12:58:10","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":235028,"visible":true,"origin":"","legend":"\u003cp\u003eVAS and JOA Scores Comparison by Surgical Segment.\u003c/p\u003e\n\u003cp\u003eThis figure presents the comparison of VAS and JOA scores between the Scalpel Group and the Drill Group across different surgical segments (C6-C7, C7-T1, C4-C5, C5-C6). The blue bars represent the Scalpel Group, and the orange bars represent the Drill Group, with error bars indicating standard deviations.\u003c/p\u003e","description":"","filename":"figure.4.png","url":"https://assets-eu.researchsquare.com/files/rs-7011869/v1/c27550ae7bc3740a8e198809.png"},{"id":86777455,"identity":"38553f39-fa2e-4b9e-b511-cb432adc25a7","added_by":"auto","created_at":"2025-07-15 12:50:11","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":230996,"visible":true,"origin":"","legend":"\u003cp\u003eVAS and JOA Scores Changes at 3 and 6 Months Postoperative in Scalpel and Drill Groups\u003c/p\u003e\n\u003cp\u003eThis figure illustrates the changes in Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) scores between the Scalpel and Drill groups at 3 and 6 months postoperative. VAS scores, indicating pain levels, show a downward trend over time for both groups, with the Scalpel group consistently showing lower scores. JOA scores, reflecting functional recovery, demonstrate an upward trend, with the Scalpel group scoring slightly higher than the Drill group at both time points. This comparison highlights the differences in pain relief and functional recovery between the two groups across the follow-up period.\u003c/p\u003e","description":"","filename":"figure.5.png","url":"https://assets-eu.researchsquare.com/files/rs-7011869/v1/eb3c42d3d95a1e344a8346cb.png"},{"id":91080219,"identity":"cc615420-b6c3-494e-b6ed-61dcf722fe15","added_by":"auto","created_at":"2025-09-11 11:32:54","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2383801,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7011869/v1/8ecbf9b9-132a-49cb-b6b2-8780e499f430.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Comparative Study of Ultrasonic Bone Scalpel and Drill in Keyhole Spinal Surgery: Efficiency, Safety, and Learning Curve Analysis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMinimally invasive spinal surgery has revolutionized the treatment of cervical radiculopathy by reducing tissue trauma and promoting faster recovery compared to conventional open procedures(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Among these techniques, the keyhole approach has gained significant traction for its ability to achieve effective nerve decompression while minimizing damage to surrounding structures(2)(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). However, the choice of surgical tools within the keyhole approach remains a matter of debate, particularly concerning the traditional drill (burr) and the ultrasonic bone scalpel.\u003c/p\u003e\u003cp\u003eThe burr, a long-standing tool in spinal surgery, is effective for bone resection but is associated with thermal damage, increased risk of dural tears, and higher rates of intraoperative nerve injury(\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e)(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). In contrast, the ultrasonic bone scalpel, with its selective tissue-cutting capability and reduced heat generation, offers a promising alternative for enhancing nerve safety during minimally invasive procedures(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Despite its theoretical advantages, the evidence directly comparing the ultrasonic bone scalpel with the burr in terms of clinical outcomes, learning curves, and postoperative complications remains sparse.\u003c/p\u003e\u003cp\u003eEarly research on ultrasonic bone scalpels has highlighted their potential to lower postoperative pain and soft tissue edema while shortening operative times(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). However, these findings are largely derived from non-spinal applications, leaving a gap in the literature regarding their role in cervical keyhole surgery. Moreover, understanding the learning curve associated with these tools is crucial for their widespread adoption in clinical practice(\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e)(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThis study aims to compare the ultrasonic bone scalpel and burr in keyhole spinal surgery for cervical radiculopathy. Specifically, we evaluate their impact on operative efficiency, learning curves, and clinical outcomes, including pain relief, functional recovery, and complication rates. By addressing these aspects, we aim to provide evidence-based guidance for optimizing tool selection in minimally invasive spinal procedures.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eStudy Design and Patient Selection\u003c/p\u003e\u003cp\u003eThis prospective cohort study was conducted between January 2023 and December 2024 at Honghui Hospital, Xi'an Jiaotong University. A total of 72 patients diagnosed with cervical radiculopathy and undergoing keyhole spinal surgery were included. Patients were divided into two groups based on the surgical instrument used: the Ultrasonic Bone Scalpel group (n = 36) and the Drill group (n = 36).\u003c/p\u003e\u003cp\u003eInclusion criteria consisted of adults aged 18–75 years, diagnosed with cervical radiculopathy confirmed by MRI and clinical symptoms, with spinal segments limited to C4-C5, C5-C6, C6-C7, or C7-T1. Patients were included if they exhibited severe pain (VAS ≥ 6) or functional impairment requiring surgical intervention. Exclusion criteria included a history of prior cervical spine surgery, the presence of systemic diseases (e.g., severe osteoporosis, malignancy, or infection), and inability to complete follow-up evaluations.\u003c/p\u003e\u003cp\u003eSurgical Techniques\u003c/p\u003e\u003cp\u003eAll surgeries were performed by two experienced spinal surgeons using a standardized keyhole technique under general anesthesia. In the Ultrasonic bone scalpel group, a ultrasonic bone scalpel (SMTP, CHN) was utilized for decompression. Operating at a frequency of 25–30 kHz, this device enabled precise bone cutting while minimizing soft tissue and nerve root damage. It was specifically used for osteophyte removal and nerve decompression. In the Drill group, a Midas Rex® high-speed drill (Medtronic, USA) was employed to perform similar procedures, including osteophyte removal and nerve decompression. Special care was taken to control heat generation and avoid nerve root injury during the procedure.\u003c/p\u003e\u003cp\u003eData Collection\u003c/p\u003e\u003cp\u003eClinical and radiological data were collected preoperatively and at 3 and 6 months postoperatively, focusing on clinical outcomes, surgical metrics, and radiological assessments.\u003c/p\u003e\u003cp\u003eClinical outcomes included VAS scores (Visual Analog Scale) for pain evaluation, JOA scores (Japanese Orthopaedic Association) for functional recovery assessment, and complication rates (e.g., intraoperative nerve root injuries, dural tears, cerebrospinal fluid leaks, and infections). Surgical metrics comprised operative time, recorded from skin incision to closure, and intraoperative blood loss, measured using suction canisters and sponges. Learning curve analysis was performed using the Cumulative Sum (CUSUM) method based on operative time. Radiological assessments were conducted using ImageJ software to analyze pre- and postoperative MRI scans, measuring the Nerve Root to Spinal Canal Wall Distance (NR-SCW, mm), Soft Tissue Edema Area (STE Area, mm²), and lesion volume (cm³).\u003c/p\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eAll statistical analyses were performed using SPSS (version 26.0; IBM, USA) and GraphPad Prism (version 9.0; GraphPad Software, USA). Statistical significance was set at p \u0026lt; 0.05.\u003c/p\u003e\u003cp\u003eContinuous variables, such as VAS scores, JOA scores, and operative time, were expressed as mean ± standard deviation (SD) and compared using independent t-tests or Mann-Whitney U tests as appropriate. Categorical variables, such as complication rates, were presented as frequencies (%) and compared using the Chi-square test or Fisher’s exact test.\u003c/p\u003e\u003cp\u003eChanges in VAS and JOA scores over time (baseline, 3 months, and 6 months) were evaluated using repeated measures ANOVA. Learning curves were assessed using CUSUM analysis of operative time, identifying the number of cases required for each group to achieve proficiency.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eBaseline Characteristics\u003c/p\u003e\u003cp\u003eA total of 72 patients were included in the study, with 36 patients in the Ultrasonic Bone Scalpel group and 36 in the Drill group. Baseline demographic and clinical characteristics, such as age, gender distribution, surgical segments, and preoperative VAS and JOA scores, were comparable between the two groups, with no statistically significant differences (all p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Detailed baseline characteristics are provided in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline Characteristics of Patients in the Ultrasonic Scalpel and Drill Groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003cp\u003eN (%)\u003c/p\u003e\u003cp\u003eMean (\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eOverall\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;72\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDrill\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;36\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eUltrasonic Scalpel\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;36\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56.68\u0026thinsp;\u0026plusmn;\u0026thinsp;4.49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e56.39\u0026thinsp;\u0026plusmn;\u0026thinsp;5.07\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e56.97\u0026thinsp;\u0026plusmn;\u0026thinsp;3.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.68\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.23\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003emale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44 (61.11%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25(69.44%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e19 (52.78%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003efemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e28 (38.89%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11(30.56%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e17 (47.22%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSegment\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.46\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC4-C5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10 (13.89%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6(16.67%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4 (11.11%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC5-C6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e30 (41.67%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14(38.89%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e16 (44.44%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC6-C7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14 (19.44%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9(25.00%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5 (13.89%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eC7-T1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e18 (25.00%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7(19.44%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11 (30.56%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eJOA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e8.61\u0026thinsp;\u0026plusmn;\u0026thinsp;1.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.59\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVAS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.46\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOperation time(min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e108.85\u0026thinsp;\u0026plusmn;\u0026thinsp;11.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e121.97\u0026thinsp;\u0026plusmn;\u0026thinsp;11.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e95.72\u0026thinsp;\u0026plusmn;\u0026thinsp;8.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.00*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBlood loss (ml)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e45.69\u0026thinsp;\u0026plusmn;\u0026thinsp;2.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e49.58\u0026thinsp;\u0026plusmn;\u0026thinsp;2.57\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e41.81\u0026thinsp;\u0026plusmn;\u0026thinsp;2.46\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.00*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIntraoperative Nerve Root Injury\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eY\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (1.39%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (2.78%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0 (0.00%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e71 (98.61%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e35 (97.22%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e36 (100.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDural Tear\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eY\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (2.78%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (5.56%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0 (0.00%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.47\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e70 (97.22%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e34 (94.44%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e36 (100.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative VAS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.17\u0026thinsp;\u0026plusmn;\u0026thinsp;1.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.55\u0026thinsp;\u0026plusmn;\u0026thinsp;1.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.00*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative VAS (3 months)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.77\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.00*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative VAS (6 months)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.46\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.00*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative JOA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e8.35\u0026thinsp;\u0026plusmn;\u0026thinsp;1.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.10\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e8.60\u0026thinsp;\u0026plusmn;\u0026thinsp;1.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.08\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative JOA (3 months)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10.91\u0026thinsp;\u0026plusmn;\u0026thinsp;1.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10.69\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11.12\u0026thinsp;\u0026plusmn;\u0026thinsp;1.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative JOA (6 months)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.85\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10.97\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e11.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLength of Hospital Stay\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.25\u0026thinsp;\u0026plusmn;\u0026thinsp;1.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.47\u0026thinsp;\u0026plusmn;\u0026thinsp;1.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre-op NR-SCW Distance (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.23\u0026thinsp;\u0026plusmn;\u0026thinsp;1.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.14\u0026thinsp;\u0026plusmn;\u0026thinsp;1.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.33\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.47\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost-op NR-SCW Distance (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.47\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.72\u0026thinsp;\u0026plusmn;\u0026thinsp;1.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.98\u0026thinsp;\u0026plusmn;\u0026thinsp;1.40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.59\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre-op STE Area (mm\u0026sup2;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e63.22\u0026thinsp;\u0026plusmn;\u0026thinsp;20.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e62.08\u0026thinsp;\u0026plusmn;\u0026thinsp;20.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e64.35\u0026thinsp;\u0026plusmn;\u0026thinsp;19.97\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.62\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost-op STE Area (mm\u0026sup2;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e26.38\u0026thinsp;\u0026plusmn;\u0026thinsp;12.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33.66\u0026thinsp;\u0026plusmn;\u0026thinsp;15.91\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e19.09\u0026thinsp;\u0026plusmn;\u0026thinsp;6.84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.00*\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre-OP Lesion Volume (cm\u0026sup3;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.95\u0026thinsp;\u0026plusmn;\u0026thinsp;1.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.90\u0026thinsp;\u0026plusmn;\u0026thinsp;1.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.71\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost-OP Lesion Volume (cm\u0026sup3;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.86\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.84\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRecurrence\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e1.00\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eY\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7 (9.72%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (11.11%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3 (8.33%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e65 (90.28%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32 (88.89%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e33 (91.67%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eAbbereviation: Pre-op NR-SCW Distance (mm): Preoperative MRI: Nerve Root to Spinal Canal Wall Distance (mm)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003ePost-op NR-SCW Distance (mm): Postoperative MRI: Nerve Root to Spinal Canal Wall Distance (mm)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003ePre-op STE Area (mm\u0026sup2;): Preoperative MRI: Soft Tissue Edema Area (mm\u003csup\u003e2\u003c/sup\u003e)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003ePost-op STE Area (mm\u0026sup2;): Postoperative MRI: Soft Tissue Edema Area (mm\u003csup\u003e2\u003c/sup\u003e)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003ePre-OP Lesion Volume (cm\u0026sup3;): Preoperative MRI: Lesion Volume (cm\u003csup\u003e3\u003c/sup\u003e)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003ePost-OP Lesion Volume (cm\u0026sup3;): Postoperative MRI: Lesion Volume (cm\u003csup\u003e3\u003c/sup\u003e)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eContinuous variables (e.g., age, BMI, NR-SCD, STE-Area, Lesion-Vol) are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD) and compared using an independent samples t-test or Mann-Whitney U test.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eCategorical variables (e.g., sex, NSAIDs usage) are shown as frequency and percentage, with group comparisons performed using Chi-square or Fisher\u0026rsquo;s exact test.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eRepeated Measures ANOVA Results\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eScore Type\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eF Value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNum DF\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eDen DF\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003ePr\u0026thinsp;\u0026gt;\u0026thinsp;F\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVAS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e149.0112\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.0000\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eJOA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e115.4413\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.0000\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003cb\u003eAbbreviations\u003c/b\u003e: DF: Degrees of Freedom; Pr\u0026thinsp;\u0026gt;\u0026thinsp;F: Probability of observing a test statistic as extreme as, or more extreme than, the value observed, under the null hypothesis.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eData are presented as Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard Deviation (SD). Group differences were analyzed using Repeated Measures ANOVA with statistical significance set at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eRepeated Measures ANOVA showed significant differences in VAS and JOA scores at postoperative 3 and 6 months (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eDegrees of freedom for each score are 1 (Num DF) and 71 (Den DF), respectively.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eSurgical Metrics\u003c/p\u003e\u003cp\u003eThe Ultrasonic Bone Scalpel group demonstrated significantly better surgical efficiency compared to the Drill group. Operative time was notably shorter in the Ultrasonic Bone Scalpel group (95.72\u0026thinsp;\u0026plusmn;\u0026thinsp;8.32 minutes) compared to the Drill group (121.97\u0026thinsp;\u0026plusmn;\u0026thinsp;11.53 minutes, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The CUSUM learning curve analysis revealed that proficiency was achieved after 10 cases in the Ultrasonic Bone Scalpel group, whereas the Drill group required 25 cases to reach a similar level (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIntraoperative blood loss was also significantly lower in the Ultrasonic Bone Scalpel group (41.81\u0026thinsp;\u0026plusmn;\u0026thinsp;2.46 mL vs. 49.58\u0026thinsp;\u0026plusmn;\u0026thinsp;2.57 mL, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). In terms of intraoperative complications, the incidence of nerve root injury was 0% in the Ultrasonic Bone Scalpel group compared to 2.78% in the Drill group (p\u0026thinsp;=\u0026thinsp;1.00). Similarly, no dural tears were observed in the Ultrasonic Bone Scalpel group, while the Drill group reported a rate of 5.56% (p\u0026thinsp;=\u0026thinsp;0.47). (Figure.3)\u003c/p\u003e\u003cp\u003eClinical Outcomes\u003c/p\u003e\u003cp\u003eThe Ultrasonic Bone Scalpel group showed superior pain relief and functional recovery compared to the Drill group. At three months postoperatively, VAS scores were significantly lower in the Ultrasonic Bone Scalpel group (1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22) compared to the Drill group (1.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.77, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and this trend was maintained at six months (1.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.00 vs. 1.46\u0026thinsp;\u0026plusmn;\u0026thinsp;1.00, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Repeated measures ANOVA confirmed a significant interaction between time and group, demonstrating greater pain relief in the Ultrasonic Bone Scalpel group (F\u0026thinsp;=\u0026thinsp;149.01, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001, Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eJOA scores also improved significantly in both groups. At three months, the Ultrasonic Bone Scalpel group achieved slightly higher scores compared to the Drill group (11.12\u0026thinsp;\u0026plusmn;\u0026thinsp;1.24 vs. 10.69\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17, p\u0026thinsp;=\u0026thinsp;0.07). At six months, the Ultrasonic Bone Scalpel group showed superior functional recovery (11.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44 vs. 10.97\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17, p\u0026thinsp;=\u0026thinsp;0.07). Repeated measures ANOVA indicated significant improvement over time (F\u0026thinsp;=\u0026thinsp;115.44, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), although the interaction effect between group and time did not reach statistical significance (p\u0026thinsp;=\u0026thinsp;0.07). (Table.2)\u003c/p\u003e\u003cp\u003eRadiological Outcomes\u003c/p\u003e\u003cp\u003eRadiological evaluations demonstrated similar patterns of improvement in both groups, with the Ultrasonic Bone Scalpel group exhibiting slightly better results. Preoperative NR-SCW distances were comparable between the two groups (3.33\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03 mm vs. 3.14\u0026thinsp;\u0026plusmn;\u0026thinsp;1.08 mm, p\u0026thinsp;=\u0026thinsp;0.47). Postoperatively, both groups achieved significant increases in NR-SCW distance, with the Ultrasonic Bone Scalpel group showing slightly greater improvements (5.98\u0026thinsp;\u0026plusmn;\u0026thinsp;1.40 mm vs. 5.72\u0026thinsp;\u0026plusmn;\u0026thinsp;1.54 mm, p\u0026thinsp;=\u0026thinsp;0.59).\u003c/p\u003e\u003cp\u003ePostoperative soft tissue edema area was significantly smaller in the Ultrasonic Bone Scalpel group (19.09\u0026thinsp;\u0026plusmn;\u0026thinsp;6.84 mm\u0026sup2;) compared to the Drill group (33.66\u0026thinsp;\u0026plusmn;\u0026thinsp;15.91 mm\u0026sup2;, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), reflecting reduced tissue damage and better soft tissue preservation. Both groups achieved similar reductions in lesion volume postoperatively (1.79\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89 cm\u0026sup3; vs. 1.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.86 cm\u0026sup3;, p\u0026thinsp;=\u0026thinsp;0.84). (Figure.1)\u003c/p\u003e\u003cp\u003eInteraction Effects\u003c/p\u003e\u003cp\u003eSubgroup analysis by surgical segment (C4-C5, C5-C6, C6-C7, C7-T1) did not reveal any statistically significant differences in VAS and JOA scores between segments (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05 for all interaction effects). However, the Ultrasonic Bone Scalpel group consistently demonstrated better outcomes across all segments (Table\u0026nbsp;3) (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTable 3: Interaction Effects Analysis by Surgical Segment\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eEffect\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSum of Squares\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eF Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePr \u0026gt; F\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eSegment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.543272\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.860508\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.4621\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.042437\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e4.953464\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.0269\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eScore_Type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e9603.793347\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e45635.4203\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.0000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eTime\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.105549\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.501550\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.4795\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eSegment:Group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.014057\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.022266\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.9955\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eSegment:Score_Type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.135253\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.214233\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.8865\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eGroup:Score_Type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e118.484240\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e563.0148\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e1.35e-66\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eSegment:Time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.631791\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e2.584655\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.0537\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eGroup:Time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.807625\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e3.837683\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.0512\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eScore_Type:Time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e54.496561\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e258.9574\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e9.84e-41\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eSegment:Group:Score_Type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.722107\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e1.143773\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.3319\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eSegment:Group:Time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.955320\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e3.097104\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.0274\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eSegment:Score_Type:Time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.535400\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.848040\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.4687\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eGroup:Score_Type:Time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.111308\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.528914\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.4677\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eSegment:Group:Score_Type:Time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.546519\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e0.865651\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e0.4594\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 246px;\"\u003e\n \u003cp\u003eResidual\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e53.874185\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 53px;\"\u003e\n \u003cp\u003e256\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 104px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u0026nbsp;\u003c/strong\u003eDF: Degrees of Freedom; Pr \u0026gt; F: Probability of observing a test statistic as extreme as, or more extreme than, the value observed, under the null hypothesis.\u003c/p\u003e\n\u003cp\u003eData are presented as Mean \u0026plusmn; Standard Deviation (SD). Group differences were analyzed using Repeated Measures ANOVA with statistical significance set at p \u0026lt; 0.05.\u003c/p\u003e\n\u003cp\u003eAnalysis of variance (ANOVA) was conducted to assess interaction effects between surgical segment, treatment group, score type, and time. Each main effect and interaction term was tested, with p-values indicating statistical significance at conventional levels (e.g., p \u0026lt; 0.05).\u003c/p\u003e\u003cp\u003eComplications and Recurrence\u003c/p\u003e\u003cp\u003eThe overall complication rates were lower in the Ultrasonic Bone Scalpel group compared to the Drill group, but this difference was not statistically significant (p\u0026thinsp;=\u0026thinsp;1.00, p\u0026thinsp;=\u0026thinsp;0.47). Recurrence rates were similarly low in both groups, with no significant differences observed (8.33% in the Ultrasonic Bone Scalpel group vs. 11.11% in the Drill group, p\u0026thinsp;=\u0026thinsp;1.00).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study provides a comprehensive comparison between the ultrasonic bone scalpel and the traditional drill in keyhole spinal surgery for cervical radiculopathy, highlighting significant advantages in operative efficiency, soft tissue preservation, clinical outcomes, and surgeon learning curves. By integrating our findings with prior research, we provide evidence-based insights into the superiority of the ultrasonic bone scalpel and the potential reasons for its improved performance.\u003c/p\u003e\u003cp\u003eOperative Efficiency and Learning Curve\u003c/p\u003e\u003cp\u003eOne of the most prominent findings of this study was the significantly shorter operative time in the ultrasonic bone scalpel group compared to the drill group. This can be attributed to the device\u0026rsquo;s ability to perform precise bone cutting without requiring additional steps to manage heat damage or minimize risks to soft tissues. Similar results have been reported in other spinal surgeries where ultrasonic devices were associated with reduced operative times due to their efficiency in cutting hard tissues while sparing soft structures(10)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn addition, our learning curve analysis demonstrated that surgeons reached proficiency after 10 cases with the ultrasonic bone scalpel, whereas 25 cases were required for the drill group. This result aligns with prior studies indicating that the intuitive handling of ultrasonic bone scalpels and their selective tissue-cutting properties reduce the cognitive and technical demands on surgeons during the learning phase (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Furthermore, a shorter learning curve is clinically significant as it facilitates the adoption of new techniques in minimally invasive surgery, ultimately improving patient outcomes and reducing the potential for surgeon error during the early phase of skill acquisition(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eSoft Tissue Preservation\u003c/p\u003e\u003cp\u003eAnother critical finding was the significantly smaller postoperative soft tissue edema area in the ultrasonic bone scalpel group, suggesting superior preservation of surrounding tissues. The ultrasonic bone scalpel\u0026rsquo;s mechanism, which combines high-frequency vibration with minimal heat generation, allows selective cutting of calcified structures while sparing elastic soft tissues such as the dura and nerve roots(\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e)(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). In contrast, traditional drills often generate excessive heat, which can cause collateral tissue damage and local inflammation, potentially contributing to larger edema areas(\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e).\u003c/p\u003e\u003cp\u003ePrevious studies in general surgery and orthopedic applications of ultrasonic devices have also reported similar benefits, including reduced soft tissue trauma and postoperative inflammation(\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). In our study, this tissue-preserving effect of the ultrasonic bone scalpel likely contributed to improved pain relief and faster functional recovery, further supporting its advantages in minimally invasive spinal procedures.\u003c/p\u003e\u003cp\u003eClinical Outcomes\u003c/p\u003e\u003cp\u003eClinical outcomes were another area where the ultrasonic bone scalpel group demonstrated superior results. Patients in this group reported significantly lower VAS scores at 3 and 6 months postoperatively, indicating better pain control compared to the drill group. Additionally, improvements in JOA scores were more pronounced in the ultrasonic bone scalpel group, reflecting better functional recovery. These findings are consistent with earlier studies in spinal surgery, where reduced tissue trauma from ultrasonic devices was linked to decreased postoperative pain and quicker neurological recovery(\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe mechanism underlying these superior outcomes is likely multifactorial. First, the reduced intraoperative trauma observed in the ultrasonic bone scalpel group minimizes the inflammatory cascade and associated pain. Second, the smaller soft tissue edema area in this group decreases postoperative nerve compression, promoting better recovery of neurological function. Finally, the more efficient surgical process associated with the ultrasonic bone scalpel may reduce systemic stress during surgery, indirectly contributing to improved recovery trajectories(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eSafety Profile\u003c/p\u003e\u003cp\u003eWhile both groups demonstrated low complication rates, the ultrasonic bone scalpel group had no cases of dural tears or nerve root injuries. Although this difference was not statistically significant, the trend is clinically relevant. Traditional drills are associated with higher risks of thermal and mechanical damage, which can lead to complications such as dural tears or nerve root irritation(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). The ultrasonic bone scalpel, on the other hand, operates with minimal thermal spread and controlled cutting, providing an inherent safety advantage(\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). These findings align with reports from other studies highlighting the safety profile of ultrasonic devices in delicate surgical fields, including neurosurgery and otolaryngology(\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eComparison with Prior Research\u003c/p\u003e\u003cp\u003eOur findings align with and extend those of earlier studies on the ultrasonic bone scalpel. Previous research in general surgery, orthopedic applications, and some spinal procedures has demonstrated the advantages of ultrasonic devices in reducing operative times, minimizing tissue trauma, and improving clinical outcomes(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e)(\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). However, few studies have directly compared the ultrasonic bone scalpel with traditional drills in keyhole spinal surgery. By filling this gap, our study provides specific evidence supporting the ultrasonic bone scalpel\u0026rsquo;s role in cervical radiculopathy treatment, highlighting its unique benefits in a minimally invasive context.\u003c/p\u003e\u003cp\u003eOne notable difference from prior research is the emphasis on learning curves. While previous studies have primarily focused on patient outcomes, our inclusion of surgeon learning curve analysis provides a broader perspective on the device\u0026rsquo;s clinical utility. This distinction underscores the importance of integrating both patient and surgeon outcomes when evaluating new surgical technologies.\u003c/p\u003e\u003cp\u003eLimitations and Future Directions\u003c/p\u003e\u003cp\u003eDespite its strengths, this study has limitations. The single-center design and relatively small sample size may limit the generalizability of our findings. Additionally, the follow-up period was restricted to 6 months, which may not capture long-term outcomes such as recurrence rates or late complications. Future multicenter studies with larger cohorts and extended follow-up periods are necessary to validate our findings and provide more comprehensive insights into the long-term benefits of ultrasonic devices in spinal surgery.\u003c/p\u003e\u003cp\u003eFurther research could also explore cost-effectiveness and patient-reported outcomes, which were beyond the scope of this study. Finally, investigating the performance of the ultrasonic bone scalpel in more complex spinal procedures or other regions of the spine could expand its clinical applications and establish its broader role in minimally invasive surgery.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study demonstrates that the ultrasonic bone scalpel is a safer, more efficient, and clinically effective alternative to the traditional drill in keyhole spinal surgery for cervical radiculopathy. By reducing operative time, minimizing tissue trauma, and improving both pain relief and functional recovery, the ultrasonic bone scalpel offers significant benefits for patients and surgeons alike. Future research should focus on validating these findings in larger populations, exploring cost-effectiveness, and assessing long-term outcomes to support the widespread adoption of ultrasonic devices in spinal surgery.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u003cb\u003ePre-op NR-SCW Distance (mm)\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePreoperative MRI:Nerve Root to Spinal Canal Wall Distance (mm)\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u003cb\u003ePost-op NR-SCW Distance (mm)\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePostoperative MRI:Nerve Root to Spinal Canal Wall Distance (mm)\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u003cb\u003ePre-op STE Area (mm\u0026sup2;)\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePreoperative MRI:Soft Tissue Edema Area (mm\u0026sup2;)\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u003cb\u003ePost-op STE Area (mm\u0026sup2;)\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePostoperative MRI:Soft Tissue Edema Area (mm\u0026sup2;)\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u003cb\u003ePre-op Lesion Volume (cm\u0026sup3;)\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePreoperative MRI:Lesion Volume (cm\u0026sup3;)\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u003cb\u003ePost-op Lesion Volume (cm\u0026sup3;)\u003c/b\u003e\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ePostoperative MRI:Lesion Volume (cm\u0026sup3;)\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisclosure of Funding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was conducted according to the guidelines of the Declaration of Helsinki. The need for approval was waived by the Ethical Committee of Honghui Hospital, Xi\u0026apos;an Jiaotong University for this retrospective study. Informed consent was obtained from all subjects involved in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eK J, Y L, Dh H, V K, S S, Js K. Minimally invasive endoscopy in spine surgery: where are we now? PubMed [Internet]. [cited 2024 Dec 29]; Available from: https://pubmed.ncbi.nlm.nih.gov/36856868/\u003c/li\u003e\n\u003cli\u003eKc M, T K, M M, M W, So E. Keyhole approaches to intradural pathologies. PubMed [Internet]. [cited 2024 Dec 29]; Available from: https://pubmed.ncbi.nlm.nih.gov/28760029/\u003c/li\u003e\n\u003cli\u003eJ L, J M, X F, X T, L S. Clinical efficacy and safety of posterior minimally invasive surgery in cervical spondylosis: a systematic review. PubMed [Internet]. 2022 [cited 2024 Dec 29]; Available from: https://pubmed.ncbi.nlm.nih.gov/35964065/\u003c/li\u003e\n\u003cli\u003eDerman PB, Phillips FM. Complication avoidance in minimally invasive spinal surgery. J Spine Surg. 2019 Jun;5(Suppl 1):S57\u0026ndash;67. \u003c/li\u003e\n\u003cli\u003eXu J, Wang D, Liu J, Zhu C, Bao J, Gao W, et al. Learning Curve and Complications of Unilateral Biportal Endoscopy: Cumulative Sum and Risk-Adjusted Cumulative Sum Analysis. Neurospine. 2022 Sep;19(3):792\u0026ndash;804. \u003c/li\u003e\n\u003cli\u003eKumar V, Neradi D, Salaria AK, Dagar A, Singh Dhatt S, Jindal K. Role of Ultrasonic Bone Scalpel in Spine Surgery: a Review Article. SN Comprehensive Clinical Medicine. 2020 Aug 28;2(10):1883\u0026ndash;9. \u003c/li\u003e\n\u003cli\u003eRenjith KR, Eamani NK, Raja DC, Shetty AP. Ultrasonic bone scalpel in spine surgery. J Orthop. 2023 May 10;41:1\u0026ndash;7. \u003c/li\u003e\n\u003cli\u003eHu Y, Dong Y, Qi J, Chen Z, Li W, Tian Y, et al. Learning Curve and Clinical Outcomes of Ultrasonic Osteotome‐based En Bloc Laminectomy for Thoracic Ossification of the Ligamentum Flavum. Orthop Surg. 2023 Jul 5;15(9):2318\u0026ndash;27. \u003c/li\u003e\n\u003cli\u003eDave BR, Krishnan A, Rai RR, Degulmadi D, Mayi S, Gudhe M. The Effectiveness and Safety of Ultrasonic Bone Scalpel Versus Conventional Method in Cervical Laminectomy: A Retrospective Study of 311 Patients. Global Spine J. 2020 Sep;10(6):760\u0026ndash;6. \u003c/li\u003e\n\u003cli\u003eP B, G C, Z P, R V, Hz R, J V. Minimally invasive spine surgery: systematic review. PubMed [Internet]. [cited 2024 Dec 29]; Available from: https://pubmed.ncbi.nlm.nih.gov/25199809/\u003c/li\u003e\n\u003cli\u003eHu X, Ohnmeiss DD, Lieberman IH. Use of an ultrasonic osteotome device in spine surgery: experience from the first 128 patients. Eur Spine J. 2013 Dec;22(12):2845\u0026ndash;9. \u003c/li\u003e\n\u003cli\u003eBansal P, Kumar V, Vatkar AJ, Gaurav A, Dhatt SS. Ultrasonic Bone Scalpel versus Conventional Methods for Osteotomy in Posterior Surgery for Cervical Spondylotic Myelopathy: A Review and Meta-Analysis. Asian Spine J. 2023 Oct;17(5):964\u0026ndash;74. \u003c/li\u003e\n\u003cli\u003eYao Z, Zhang S, Liu W, Wei M, Fang W, Li Q, et al. The efficacy and safety of ultrasonic bone scalpel for removing retrovertebral osteophytes in anterior cervical discectomy and fusion: A retrospective study. Scientific Reports. 2024 Jan 2;14(1):80. \u003c/li\u003e\n\u003cli\u003eWu W, Lin XB, Qian JM, Ji ZL, Jiang Z. Ultrasonic aspiration hepatectomy for 136 patients with hepatocellular carcinoma. World J Gastroenterol. 2002 Aug 15;8(4):763\u0026ndash;5. \u003c/li\u003e\n\u003cli\u003eBi B, Ca I, S I, G D, R B, M O, et al. Complications in Minimally Invasive Spine Surgery in the Last 10 Years: A Narrative Review. PubMed [Internet]. [cited 2024 Dec 29]; Available from: https://pubmed.ncbi.nlm.nih.gov/39363458/\u003c/li\u003e\n\u003cli\u003eShl T, Cw C, Ty L, Yc W, Cb W, Ak G, et al. The Use of Ultrasonic Bone Scalpel (UBS) in Unilateral Biportal Endoscopic Spine Surgery (UBESS): Technical Notes and Outcomes. PubMed [Internet]. 2023 [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/36769829/\u003c/li\u003e\n\u003cli\u003eN H, T M, Y M, S T, T M, T F. Potential risk of thermal damage to cervical nerve roots by a high-speed drill. PubMed [Internet]. [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/19880905/\u003c/li\u003e\n\u003cli\u003eCp C, Ps da SR, Flf M, Mm F, M de FF. Hemostasis with the Ultrasonic Scalpel. PubMed [Internet]. [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/30626994/\u003c/li\u003e\n\u003cli\u003eJm S, J N, Rv H, Ne W, A J. Ultrasonic bone removal from the ossicular chain affects cochlear structure and function. PubMed [Internet]. 2021 [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/33810814/\u003c/li\u003e\n\u003cli\u003eY C, Z C, X Y, R S, W H. Use of Ultrasonic Device in Cervical and Thoracic Laminectomy: a Retrospective Comparative Study and Technical Note. PubMed [Internet]. 2018 [cited 2025 Jan 1]; Available from: https://pubmed.ncbi.nlm.nih.gov/29507350/\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Ultrasonic Bone Scalpel, Cervical Radiculopathy, Keyhole Spinal Surgery, Minimally Invasive Spine Surgery, Learning Curve","lastPublishedDoi":"10.21203/rs.3.rs-7011869/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7011869/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eMinimally invasive spinal surgery has transformed the management of cervical radiculopathy by reducing tissue trauma and enhancing recovery. However, the optimal surgical tool for keyhole spinal procedures\u0026mdash;ultrasonic bone scalpel or traditional drill\u0026mdash;remains debated. This study aimed to compare these tools regarding operative efficiency, learning curves, clinical outcomes, and complication rates.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eA prospective cohort study was conducted involving 72 patients with cervical radiculopathy who underwent keyhole spinal surgery at a single tertiary care center. Patients were assigned to the ultrasonic bone scalpel group (n\u0026thinsp;=\u0026thinsp;36) or the drill group (n\u0026thinsp;=\u0026thinsp;36). Data on operative time, intraoperative blood loss, clinical outcomes (VAS, JOA scores), complications, and radiological assessments (NR-SCW distance, STE area) were collected preoperatively and at 3 and 6 months postoperatively. Statistical analyses included independent t-tests, repeated measures ANOVA, and CUSUM analysis.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe ultrasonic bone scalpel group demonstrated significantly shorter operative times (95.72\u0026thinsp;\u0026plusmn;\u0026thinsp;8.32 vs. 121.97\u0026thinsp;\u0026plusmn;\u0026thinsp;11.53 minutes, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), lower intraoperative blood loss (41.81\u0026thinsp;\u0026plusmn;\u0026thinsp;2.46 vs. 49.58\u0026thinsp;\u0026plusmn;\u0026thinsp;2.57 mL, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and smaller postoperative soft tissue edema areas (19.09\u0026thinsp;\u0026plusmn;\u0026thinsp;6.84 mm\u0026sup2; vs. 33.66\u0026thinsp;\u0026plusmn;\u0026thinsp;15.91 mm\u0026sup2;, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) compared to the drill group. Pain relief (VAS scores) and functional recovery (JOA scores) were superior in the ultrasonic bone scalpel group at both 3 and 6 months. The learning curve analysis revealed that proficiency was achieved after 10 cases in the ultrasonic bone scalpel group, compared to 25 cases in the drill group. No significant differences in complication rates or recurrence were observed between groups.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eThe ultrasonic bone scalpel offers significant advantages in operative efficiency, soft tissue preservation, and clinical outcomes while providing a shorter learning curve. These findings support its broader adoption in minimally invasive spinal surgery for cervical radiculopathy.\u003c/p\u003e","manuscriptTitle":"Comparative Study of Ultrasonic Bone Scalpel and Drill in Keyhole Spinal Surgery: Efficiency, Safety, and Learning Curve Analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-15 12:50:05","doi":"10.21203/rs.3.rs-7011869/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b23ba98c-6e0c-479d-a509-5a9eca9077ef","owner":[],"postedDate":"July 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-11T11:24:42+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-15 12:50:05","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7011869","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7011869","identity":"rs-7011869","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}