Safety and efficacy of cervical laminoplasty using a piezosurgery device compared with a high-speed drill

The efficacy and safety of ultrasonic bone scalpel for removing retrovertebral osteophytes in anterior cervical discectomy and fusion: A retrospective study

In this study, we present a novel surgical method that utilizes the ultrasonic bone scalpel (UBS) for the removal of large retrovertebral osteophytes in anterior cervical discectomy and fusion (ACDF) and evaluate its safety and efficacy in comparison to the traditional approach of using high-speed drill (HSD). A total of 56 patients who underwent ACDF for retrovertebral osteophytes were selected. We recorded patients' baseline information, operation time, intraoperative blood loss, complications, JOA and VAS scores, and other relevant data. The mean operation time and the mean intraoperative blood loss in the UBS group were less than those in the HSD group (P < 0.05). Although both groups exhibited considerable improvements in JOA and VAS scores following surgery, there was no statistically significant difference between the two groups (P > 0.05). Additionally, no significant disparities were found in bone graft fusion between the two groups at 6- and 12-months postsurgery. Notably, neither group exhibited complications such as dura tear or spinal cord injury. Our study found that the use of UBS reduced operative time, minimized surgical bleeding, and led to clinical outcomes comparable to HSD in ACDF. This technique offers an effective and safe method of removing large retrovertebral osteophytes.

Using Piezosurgery in Anterior Cervical Discectomy and Fusion to Treat Complex Cervical Spondylotic Myelopathy Is Safe and Effective

Objective

To investigate the safety and efficacy of piezosurgery in anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM).

Methods

47 patients with complex CSM (cCSM) underwent ACDF surgery from 2014 to 2017. Among these patients, 26 underwent ACDF using piezosurgery (group A) and 21 underwent ACDF by using traditional tools such as high-speed air drill, bone curette, and Kerrison bone punch (group B). Average surgical time, intraoperative blood loss, surgical complications, preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, and improvement rate were measured.

Results

Average surgical time and intraoperative blood loss were significantly lower in group A than those in group B (P < 0.01). The incidences of surgical complications were 3.8% and 23.8% in the A and B groups (P < 0.05), respectively. There were no significant differences in JOA scores and improvement rates between data collection periods at preoperative, 3-day postoperative, and 1-year postoperative follow-ups (P > 0.05).

Conclusion

For treating cCSM, both the piezosurgery and traditional tools led to significant neurological improvement. However, the piezosurgery was superior to the traditional tools in terms of surgical time, blood loss, and complication rate. Hence, piezosurgery was a safe and effective adjunct for ACDF treating cCSM.

Ultrasonic Bone Scalpel versus Conventional Methods for Osteotomy in Posterior Surgery for Cervical Spondylotic Myelopathy: A Review and Meta-Analysis

Posterior methods for cervical myelopathy include laminoplasty and laminectomy with/without fusion. A more recent innovation in these treatments is the use of an ultrasonic bone shaver for osteotomy. In this study, we examined the perioperative results after laminectomy/laminoplasty between conventional methods (rongeur/high-speed drill) vs. piezosurgery-based instruments. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed and the search was performed on four databases (PubMed, Scopus, EMBASE, and Google Scholar). Seven comparative studies were chosen after thorough screening by the authors and a meta-analysis was performed between piezosurgery and conventional technique to ascertain intraoperative and postoperative results after laminectomy/laminoplasty. The analysis includes four retrospective cohort studies and three randomized controlled trials published between 2015 and 2022. The mean age ranged from 55.5 to 64.2 years. Blood loss was significantly reduced in the piezosurgery group, other findings were not significant. On subgroup analysis, laminoplasty dramatically reduced blood loss and the rate of iatrogenic dural rips in the piezosurgery group. The use of ultrasonic bone shaver for osteotomy in cervical spondylotic myelopathy is related to significantly decreased blood loss and no significant increase in postoperative drainage, operative time, complication rate, and functional outcomes as compared to traditional techniques. We noticed significantly reduced blood and rate of dural tears in the laminoplasty subgroup with the use of ultrasonic bone shaver, which was not mirrored in the laminectomy subgroup. Careful intraoperative handling of the instrument can help prevent iatrogenic dural tears and nerve damage.

Ultrasonic bone scalpel in spine surgery

Background

Spine surgery has always been considered technically demanding even in the hands of the most experienced surgeon on account of close proximity of vital soft tissue structures. Technical advancements over the last few decades have been crucial for the progress of this complex speciality which not only increased the surgical accuracy, but patient safety as well. Ultrasonic devices are one such innovation based on piezoelectric vibrations, patented by Fernando Bianchetti, Domenico Vercellotti, and Tomaso Vercellotti in 1988.

Methods

We did an extensive literature search on ultrasonic devices and their applications in the field of spine surgery.

Results

We present the various ultrasonic bone devices available including their physical, technologic and clinical aspects in spine surgery. We also attempt to cover the limitations and future advances of Ultrasonic bone scalpel (UBS) in particular, which would be interesting and informative for any spine surgeon who is novice in this field.

Conclusion

UBS has been found to be safe and effective in all forms of spine surgeries offering distinct advantages over conventional instruments, although limited by an inherent learning curve.

Thoracic Myelopathy in Ossified Ligamentum Flavum: Surgical Management and Long-Term Outcome Following 2 Different Techniques of Surgical Decompression

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Thoracic ossified ligamentum flavum (TOLF) has been reported to present with varying degrees of neuro-deficit and multiple factors have been purported to affect its outcome. Purpose of study was to analyze factors affecting outcome and impact of ultrasonic osteotome (UO).

METHODS

We retrospectively reviewed patients treated for thoracic myelopathy secondary to OLF between 2010 and 2017. 77 patients with complete clinico-radiological records and 2 years follow-up were included. Initial 45 patients, conventional high-speed burr (HSB-group A) was used for decompression. In others, UO was used in combination with HSB (group B). Myelopathy was graded using modified Japanese orthopaedic association grading pre-operatively and each postoperative visit. At final follow-up, recovery rate was calculated. Radiological details including location, morphology, dural ossification, signal change and spinal ossifications were recorded.

RESULTS

Mean mJOA at presentation and final follow-up were 4.3±1.8 and 7.6±1.9 respectively (p = 0.001). HRR was 49.9±23 at final follow-up. A significant reduction in dural tear (12.5%; 29%) and surgical time (125.8±49.5; 189.4±52.5) were observed in group B (p = 0.00). However, there was no statistically significant difference (p = 0.18) in recovery rates between groups A (44.8±26.1) and B (52.8±24.3). Symptom duration (p = 0.00), severity of myelopathy (p = 0.04) and cord signal changes on MRI (p = 0.02) were important predictors of outcome.

CONCLUSION

Use of UO significantly reduced operative time and dural tears, although resulted in similar recovery rate as compared with HSB. Pre-operative severity of myelopathy, symptom duration and presence of cord signal change were the most significant predictors of outcome.

The H Laminectomy: Technical Description and Clinical Experience From the First 85 Patients

BACKGROUND

Over the years, lumbar laminectomy has been widely employed by spinal surgeons for many purposes throughout the spinal canal. The Misonix BoneScalpel relies on ultrasonic energy and allows the surgeon to make precise osteotomies while protecting collateral or adjacent soft tissue structures. Amplification of electric impulses allows the blade in the BoneScalpel to oscillate at very high frequencies, which thus allow it to cut bone with immense amounts of heat, which are then tempered with copious irrigation to prevent overheating. The purpose of this study is to outline and detail an innovative technique while providing insight into the technique's clinical application in a variety of spine surgeries.

METHODS

Data were retrospectively collected from medical charts and surgical reports from February 2018 to July 2021 for each surgery in which the ultrasonic scalpel was used to perform the H laminectomy. Baseline demographic information was recorded, including age, gender, laminectomy indication, and the number of levels of laminectomy.

RESULTS

A total of 85 patients (64 women, 21 men) were included in this study. The mean age of the patients was 63.7 years. Of those patients, 42.4% underwent H laminectomy for degenerative stenosis without instrumentation, 31.8% for degenerative stenosis with instrumentation, 9.4% for traumatic injuries, and 7.1% for revision surgery with instrumentation. Approximately 55% of patients underwent laminectomy of 2 or more levels, while the rest underwent single-level laminectomy. No patients had a dural tear or cerebrospinal fluid (CSF) leak as a result of the BoneScalpel.

CONCLUSIONS

The H laminectomy is another safe and effective way to perform a lumbar laminectomy. The technique has not been previously reported in the literature. No patients experienced a dural tear or CSF leak from the BoneScalpel using the H laminectomy technique. This technique affords the surgeon enhanced control of the dura-ligamentum interface. Even if the surgeon is not very experienced with the BoneScalpel, this technique provides an inherent safety mechanism with constant visualization/tactile feedback of the tip of the instrument and osteotome.

LEVEL OF EVIDENCE: 3

Safety and Effectiveness of Modified Expansive Open-door Laminoplasty Using a Ultrasonic Bone Scalpel Compared With a High-speed Drill

STUDY DESIGN

This was a retrospective study.

OBJECTIVE

Our study aimed to compare the effectiveness and safety of ultrasonic bone scalpel (UBS) and high-speed drill (HSD) in modified expansive open-door laminoplasty.

SUMMARY OF BACKGROUND DATA

The traditional methods of decompression mostly use HSD and laminectomy forceps to lift the lamina. As a new type of bone cutting instrument, UBS has the advantages of good tissue selectivity, bone cutting accuracy, good hemostasis, cold cutting, and easy operation, leading to its popular use in surgery.

MATERIALS AND METHODS

Forty-two patients who underwent modified expansive open-door laminoplasty for multilevel cervical spondylotic myelopathy were included in this study. They were divided into HSD and UBS groups (n=18 and 24, respectively). Data on demographics, operation duration, blood loss, postoperative drainage, extubation time, length of stay, cost of hospitalization, and complications were collected and compared. Modified Japanese Orthopedic Association score, visual analog scale, Neck Disability Index, and axial symptoms were also recorded and analyzed.

RESULTS

The blood loss in the UBS group was 255.4±217.5 mL, which was lower than that in the HSD group (490.6±389.4 mL, P=0.030). The cost of hospitalization was similar between the 2 groups. The operative time and postoperative drainage did not significantly differ (P>0.05). The modified Japanese Orthopedic Association score, visual analog scale score, and Neck Disability Index score after surgery were better than those before surgery (P<0.05), but no significant difference existed between the 2 groups in each period (P>0.05). No significant difference existed in the incidence of axial symptoms and other complications (P>0.05).

CONCLUSION

The application of the UBS to modified open-door laminoplasty resulted in a safe and effective decompression effect and reduced blood loss without increasing cost benefit.

Comparison of Total Laminectomy and Pedicle Screw Internal Fixation with Ultrasonic- and Microscopic-Assisted Laminectomy Replantation for Tumors of the Lumbar Spinal Canal: A Retrospective Study of 60 Cases from a Single Center

BACKGROUND Total laminectomy with pedicle screw internal fixation is the most common surgical procedure for patients with primary tumors arising in the spinal canal, but the procedure has several limitations. This study aimed to compare total laminectomy and pedicle screw internal fixation with ultrasound- and microscope-assisted laminectomy replantation surgery in patients with tumors of the lumbar spinal canal. MATERIAL AND METHODS A retrospective study was conducted. Sixty patients with tumor spinal canal were admitted to our hospital. Patients in group A (n=32) underwent total laminectomy and pedicle screw internal fixation; patients in group B (n=28) underwent laminectomy replantation with ultrasonic and microscopic assistance. Operative time, intraoperative blood loss, operative segment, length of hospital stay, postoperative length of bed rest, and visual analog scale (VAS) score after surgery were analyzed. RESULTS Hospital stay and postoperative bed rest time of patients in group B were shorter than those in group A (P=0.004). Intraoperative blood loss, postoperative drainage volume, and postoperative pain relief of group B were significantly lower than those of group A (P=0.000). There was no significant difference in postoperative pathological results between the 2 groups (P=0.901). CONCLUSIONS Ultrasound- and microscope-assisted laminectomy replantation resulted in the reduced intraoperative blood loss, postoperative drainage volume, length of hospital stay, and postoperative VAS pain score, compared with total laminectomy and pedicle screw internal fixation for the surgical removal of tumors of the lumbar spinal canal.

Drilling Speed and Bone Temperature of a Robot-assisted Ultrasonic Osteotome Applied to Vertebral Cancellous Bone

STUDY DESIGN

An experimental investigation of a robot-assisted ultrasonic osteotome applied to vertebral cancellous bone.

OBJECTIVE

The aim of this study was to investigate the effect of various ultrasonic parameter settings on temperature in the drilling site and penetration time and determine the most suitable parameters for efficient and safe robot-based ultrasonically assisted bone drilling in spinal surgery.

SUMMARY OF BACKGROUND DATA

A robot-assisted ultrasonic osteotome device may be safe and effective for spinal drilling.

METHODS

Sixty specimens of bovine vertebral cancellous were randomly assigned to one of six groups, which varied by mode of ultrasonic vibration (L-T and L) and feed rate (one percent [0.8 mm/s], two percent [1.6 mm/s], and three pecent [2.4 mm/s]). Maximum temperature in the drilling site and penetration time was recorded.

RESULTS

Maximum temperature in the drilling site decreased as output power increased for L-T and L modes, was significantly lower for L-T compared to L mode at each feed rate and power setting, was significantly different at feed rates of 1.6 mm/s versus 0.8 mm/s and 2.4 mm/s versus 0.8 mm/s for L-T mode at an output power of 60 W and 84 W, but was not influenced by feed rate for L mode. Penetration time did not significantly improve as output power increased for both L-T and L modes, was significantly decreased with increased feed rates, but was not significantly different between L-T and L modes.

CONCLUSION

The optimal parameters for applying a robot-assisted ultrasonic osteotome to vertebral cancellous bone are L-T mode, maximum output power of 120 W, and maximum feed rate of 2.4 mm/s.Level of Evidence: 4.

The Effectiveness and Safety of Ultrasonic Bone Scalpel Versus Conventional Method in Cervical Laminectomy: A Retrospective Study of 311 Patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The aim of this study was to compare the results of cervical laminectomy (CL) performed with ultrasonic bone scalpel (UBS) or conventional method (CM).

METHOD

This study comprised 311 CL performed by a single surgeon between January 2004 and December 2017. Group A (GpA) comprised 124 cases of CL performed using UBS, while Group B (GpB) comprised 187 cases of CL performed using CM. These 2 groups were compared in terms of demographic characteristics of patients, duration of surgery, estimated blood loss, and surgical complications.

RESULTS

GpA included 112 males and 12 females, mean age being 61.18 years. GpB comprised 166 males and 21 females, mean age being 62.04 years. Mean duration of surgery, estimated blood loss, and length of hospital stay was 65.52/70.87 minutes, 90.24/98.40 mL, and 4.80/4.87 days in GpA and GpB, respectively. Six patients were reported to have dural injuries in each group. In GpA, 2 cases of C5 palsy and 1 nerve root injury was observed, while in GpB, 3 cases of C5 palsy and no nerve root injury was reported. One patient had developed transient neurological deterioration postsurgery in GpA as against 11 patients in GpB.

CONCLUSION

Neurological complications observed in CM leads to intensive care unit admission, additional morbidity, and additional expenditure, whereas UBS provides a safe, rapid, and effective means of performing CL, thereby decreasing the rate of surgical complications and postoperative morbidity.

Correlation between C7 slope and cervical lordosis in patients after expansive open-door laminoplasty

Purpose of the article: To investigate the correlation between C₇ slope and cervical lordosis in patients after expansive open-door laminoplasty (EOLP).Material and methods: We retrospectively analyzed 57 patients who underwent EOLP between June 2013 and January 2017 in the Department of Spinal Surgery of our hospital. The operation time, intraoperative blood loss and follow-up time were recorded. The C₇ slope, C_2-7 sagittal vertical axis, and C_2-7 Cobb angle were measured anteroposterior radiograph of the cervical spine preoperatively and postoperatively. All patients were divided into two groups according to the preoperative C₇ slope (C₇ slope ≤20° group and C₇ slope >20° group).Results: The amount of intraoperative bleeding was 220.2 ± 180.9ml, and the operation time was 143.4 ± 51.2min. The average follow-up time was 24.9 ± 10.3months (range12-48 months). The C_2-7 Cobb angle was 13.49 ± 10.46°at the final follow-up, which was significantly lower than that preoperatively (p = .026). But, The C₇ slope and C_2-7 sagittal vertical axis showed no significant difference between preoperatively and postoperatively. Preoperative and postoperative C₇ slope and C_2-7 Cobb angle were positively correlated to age and significant difference was observed. In the group of C₇ slope >20°, significant difference was observed in term of the change of the C_2-7 Cobb angle and C_2-7SVA postoperatively (p = .009 and p= .020). However, there was no statistically significant difference detected in these two parameters in the group of C₇ slope ≤20°.Conclusion: This study indicated that C₇ slope could be used as an indicator of the change in the curvature of the cervical spine after EOLP. The loss of cervical curvature after surgery was prone to occur when C₇ slope was greater than 20°, which should be noted in clinical practice.

Efficacy of local infiltration analgesia with ropivacaine for postoperative pain management in cervical laminoplasty: a retrospective study

Poor postoperative pain control impairs patient recovery and lengthens the duration of hospitalization after various surgeries. Local infiltration analgesia(LIA) has become an effective method for managing postoperative pain. This study aimed to investigate the efficacy of LIA with ropivacaine for postoperative pain control after cervical laminoplasty. In total, 68 patients undergoing cervical laminoplasty were included for retrospective review and divided into ropivacaine and control groups. The visual analogue scale (VAS) score, postoperative analgesic consumption, operative duration, intraoperative blood loss volume, incision length, hospitalization duration and incidence of complications were analyzed. In the ropivacaine group, the VAS score was 3.2 ± 1.4 at 4 hours postoperatively, which was lower than that of the control group(4.0 ± 1.4, P = 0.024). At 8, 12 and 24 hours after surgery, a significant difference was detected in the VAS score between the two groups(P ≤ 0.015). Sufentanil consumption was less in the ropivacaine group than in the control group in the first 4 hours postoperatively (25.6 ± 6.3 µg vs 32.2 ± 6.8 µg, P < 0.001), and similar results were observed in the first 8, 12, 24, 48 and 72 hours postoperatively(P < 0.001). Fewer patients required rescue analgesia in the ropivacaine group(8/33 vs 18/35 at 4–8 hours, P = 0.021; 9/33 vs 21/35 at 8–12 hours, P = 0.007). The hospitalization duration and time to ambulation were shorter in the ropivacaine group(8.5 ± 1.4 vs 9.6 ± 1.6 for postoperative duration, P = 0.002; 2.9 ± 0.7 vs 3.5 ± 0.8 for time to ambulation, P = 0.001). The incidence of nausea and vomiting was lower in the ropivacaine group than in the control group(30.3% vs 54.3%, P = 0.046). In conclusion, LIA with ropivacaine could effectively reduce postoperative pain, and postoperative analgesic consumption, and promote recovery after cervical laminoplasty.

Clinical Investigation of the Association of Opening Size with Sagittal Canal Diameter Based on Single-Door Cervical Laminoplasty

Background

Many clinical studies have assessed the association of laminoplasty opening size (LOS) with sagittal canal diameter (SCD) based on single-door cervical laminoplasty (SDCL). Nevertheless, the “worn-off” lamina extracted in SDCL was neglected in these reports. We aimed to develop a simple mathematical model to analyze the relationship between the effective LOS and SCD, taking into consideration the worn-off lamina.

Material/Methods

A total of 106 patients treated by SDCL at our hospital were included in this study. Pre-operative and post-operative SCDs were assessed using a picture archiving and communication system (PACS) based on computed tomography scans. Mini-plate sizes as well as drill bit diameters were recorded in detail in order to determine the effective LOS for each vertebral lamina involved.

Results

SCD in all patients was increased significantly after SDCL (P<0.01). A linear correlation was found between effective LOS and the post-operative SCD increment from C3 to C7 (R²>0.933, P<0.001). The 12 mm mini-plate was most often used in SDCL, accounting for 64.45% of all cases, whereas 10 mm and 16 mm mini-plates were the least used, accounting for 3.85% and 3.00%, respectively.

Conclusions

There is a strong linear correlation between effective LOS and the post-operative SCD increment. The SCD was increased by about 0.5 mm per mm increase in effective LOS. Thus, post-operative SCD could be precisely calculated and predicted, enabling the selection of optimal mini-plate prior to SDCL.

Ultrasonic bone scalpel: utility in cervical corpectomy. A technical note

PURPOSE

Anterior cervical corpectomy and fusion (ACCF) is a technically challenging surgery. Use of conventional instruments like high-speed burr and kerrison rongeurs is associated with high complication rates such as increased blood loss and incidental durotomy. Use of ultrasonic bone scalpel (UBS) in cervical corpectomy helps to minimize such adverse events.

METHODS

We performed a retrospective study based on the data of 101 consecutive patients who underwent cervical corpectomies with UBS for different cervical spine pathologies from December 2014 to December 2016. Total duration of surgery, time taken for corpectomy, estimated blood loss, and incidental durotomies were noted.

RESULTS

Total surgical time was 30-80 min (59.36 ± 13.21 min) for single-level ACCF and 60-120 min (92.74 ± 21.04 min) for double-level ACCF. Time taken for single-level corpectomy was 2 min 11  ± 10 s and 3 min 41  ± 20 s for double-level corpectomy. Estimated blood loss ranged from 20-150 ml (52.07 ± 29.86 ml) in single level and 40-200 ml (73.22 ± 41.64 ml) in double level. Four (3.96%) inadvertent dural tears were noted, two during single-level corpectomy and other two during double-level corpectomy.

CONCLUSIONS

Use of UBS is likely to provide a safe, rapid, and effective surgery when compared to conventional rongeurs and high-speed burr. The advantages such as lower blood loss and lower intra-operative incidental dural tears were noted with the use of UBS.

[Safety and effectiveness of ultrasonic osteotome in posterior cervical laminectomy decompression and fusion]

Objective

To explore the safety of ultrasonic osteotome used in posterior cervical laminectomy decompression surgery and its effect on surgical outcome.

Methods

A clinical data of 52 patients with ossification of posterior longitudinal ligament of cervical spine (C-OPLL) undergoing posterior cervical laminectomy decompression and fusion (PCLDF) between April 2013 and April 2017 was retrospectively analysed. The patients were divided into two groups according to whether using the ultrasonic osteotome during operation: group A (20 cases, ultrasonic osteotome group) and group B (32 cases, traditional gun-clamp decompression group). There was no significant difference in gender, age, body weight, height, preoperative hemoglobin, and Japanese Orthopedic Association (JOA) score between the two groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage volume, hospitalization time, complications, hemoglobin at 1 day after operation, and JOA score at 6 months after operation were recorded and compared between the two groups, and the improvement rate of JOA was calculated.

Results

The operation time and intraoperative blood loss in group A were significantly less than those in group B ( P<0.05); there was no significant difference in the drainage volume and hospitalization time between the two groups ( P>0.05). The hemoglobin of group B was slightly higher than that of group A at 1 day after operation, but there was no significant difference between the two groups ( t=-1.260, P=0.214). All the patients were followed up 6-10 months (mean, 7.6 months). No serious complications such as C ₅ nerve paralysis, dural tear, infection, epidural hematoma, deep venous thrombosis, pulmonary embolism, transfusion allergy, or shock occurred during and after operation. The JOA scores of the two groups were significant improved at 6 months after operation when compared with preoperative scores ( P<0.05), and there was no significant difference in JOA score and improvement rate between the two groups at 6 months after operation ( P>0.05).

Conclusion

Compared with the traditional gun-clamp decompression, the effectiveness of PCLDF in treatment of C-OPLL by using ultrasonic osteotome is comparable, but the latter can effectively reduce the operation time and blood loss.

Use of Ultrasonic Device in Cervical and Thoracic Laminectomy: a Retrospective Comparative Study and Technical Note

Multilevel severe compressive myelopathy is a challenging disorder for the surgeons, the aim of this study is to assess the efficacy and safety of a newly designed ultrasonic burr as an assistant tool to the ultrasonic scalpel in laminectomy for this disease. This is a retrospective comparative study, the included subjects were patients who received cervical and thoracic laminectomy using ultrasonic device (LUD, n = 9, 10 surgeries) and controls with the high-speed burr (LHB, n = 16). Fifteen patients (60.0%) showed severe cord occupancy and the average number of laminae operated was 3.5. Ultrasonic devices caused less blood loss (P = 0.02) and quicker operative time per level (P < 0.001) than LHB, and was associated with more operated laminae (P = 0.04). Preoperative JOA scores (P = 0.51), improvement rate (P = 0.47), and dural injury (P = 0.51) were not related to LUD. Our experience indicates ultrasonic devices are safe and effective for laminectomy treating multilevel and severe compressive myelopathy, the instrument could be used with ease especially for cases with ossified posterior longitudinal ligament and ossification of the ligamentum flavum, proper utility of the instrument is crucial to prevent complications.

Relationship of actual laminoplasty opening size and increment of the cross-sectional area based on single-door cervical laminoplasy

BACKGROUND

Amounts of clinic research have been performed to investigate the increment of cross-sectional area in single-door cervical laminoplasty (SDCL). However, no one has taken the effects of surgery drill into consideration.

METHODS

A mathematical model was built to investigate the relation of actual laminoplasty opening size (LOS), the transverse canal diameter (TCD), and the increment of cross-sectional area in SDCL). The model was based on geometric analysis on deformation of spinal canal; the relation was derived and characterized as: (Equation is included in full-text article.), where a is the TCD, b the actual LOS, c the size of mini-plate, and d is diameter of the surgery drill bit. In the equation, the related variables would be measured to estimate the increment of cross-sectional area before the surgery. In the current research, 25 patients authorized to use their CT scans of C3∼C7 as the subject samples.

RESULTS

The effects of surgery SDCL were very significant; for each patient, the cross-sectional area was enlarged dramatically after the surgery (P < .01). On the contrary, the difference between the cross-sectional area obtained by the equation and that measured by software was statistically negligible (P > .05), which confirmed the reliability of the modeling equation.

CONCLUSIONS

Before the SDCL, increment of the cross-sectional area can be estimated by the above-mentioned modeling equation with a high-level reliability. This method ensures the optimum selection of mini-plate before operation for each patient.

Lumbar laminotomy and replantation for the treatment of adult spinal epidermoid cyst: A case report

RATIONALE

Adult spinal epidermoid cyst (SEC) is a rare tumor. Lumbar laminectomy and tumor removal was a routine surgical procedure for adult spinal epidermoid cyst according to the literature, but postoperative lumbar instability and intractable low back pain may occur. In this study, we presented a brief report of an adult lumbar epidermoid cyst and introduced another surgical approach.

PATIENT CONCERNS

This 28-year-old woman has been complaining of the severe right buttock pain and right thigh radiating pain for half a year. She had been diagnosed as sacroiliitis, spinal arthritis, and lumbar disc herniation at 3 different hospitals before coming to our hospital. And she received a variety of conservative treatments, including non-steroidal anti-inflammatory drugs, aspirin, acetaminophen, glucocorticoids, acupuncture, physical therapy, and so on. However, her pain did not diminish at all. Finally, we find a space-occupying lesion in her lumbar magnetic resonance images (MRI). The lesion was slightly low, equal, and uneven equal-low signals on T1WI. T2WI showed slightly higher, equal, and uneven equal-high signals. And a thin-rim enhancement was observed on Gd-DTPA-enhanced MRI.

DIAGNOSES

Adult spinal epidermoid cyst.

INTERVENTIONS

The patient underwent a surgery of lumbar laminectomy, tumor excision, and spinous process-vertebral plate in situ replantation.

OUTCOMES

Postoperative pathology prompted that the tumor was cystoid. The patient's symptoms were completely removed 1 week after surgery. Three-month postoperative MRI confirmed that the spinal epidermoid cyst had been completely removed and three-dimensional CT prompted lumbar lamina in situ. Bony fusion occurred at 6 months after the surgery.

LESSONS

Lumbar laminotomy and replantation provides an ideal option to treat adult spinal epidermoid cyst because it can completely remove the cyst and simultaneously reduce the risk of iatrogenic lumbar instability.

Piezosurgery—A Safe Technique to Perform Lateral Suboccipital Craniotomy?

BACKGROUND

Piezosurgery (PS) is a relatively new technique based on microvibrations generated by the piezoelectric effect. It selectively cuts bone tissue and preserves the surrounding soft tissue.

OBJECTIVE

To evaluate the use of PS for performing lateral suboccipital craniotomy.

METHODS

PS was used to perform a lateral suboccipital craniotomy in 22 patients who underwent surgery for different cerebellopontine angle (CPA) pathologies in the neurosurgical department. The applicability of PS for lateral suboccipital craniotomy was evaluated with respect to safety, preciseness of bone cutting, and in particular the preservation of the adjacent dura and sigmoid and transverse sinuses.

RESULTS

Lateral suboccipital craniotomy in 22 patients who underwent surgery for different CPA pathologies (13 vestibular schwannoma, 5 petrous bone meningioma, 1 petroclival meningioma, 2 epidermoid cysts, and 1 petrous bone cholesterol granuloma) was performed with PS without any complications. A burr hole was set before piezosurgical craniotomy in 6 patients, with no prior burr hole in 16 patients. Incidental durotomy during piezosurgical craniotomy occurred in 6 patients, and small lacerations of the sigmoid sinus caused by the piezosurgical device were observed in 3 patients.

CONCLUSION

Although PS is a safe and selective bone cutting technique that preserves the surrounding soft tissue, it can still lead to unintended dural tears during lateral suboccipital craniotomy. This must be kept in mind when using PS for craniotomies and relying on the selective bone cutting properties of PS.