Post-operative nerve injuries after cervical spine surgery

Risks for prolonged mechanical ventilation and reintubation after cervical malignant tumor surgery: a nested case-control study

PURPOSE

Prolonged mechanical ventilation (PMV) and reintubation are among the most serious postoperative adverse events associated with malignant cervical tumors. In this study, we aimed to clarify the incidence, characteristics, and risk factors for PMV and reintubation in target patients.

METHODS

This retrospective nested case-control study was performed between January 2014 and January 2020 at a large spinal tumor center in China. Univariate analysis was used to identify the possible risk factors associated with PMV and reintubation. Logistic regression analysis was performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) with covariates of a probability < 0.05 in univariate analysis.

RESULTS

From a cohort of 560 patients with primary malignant (n = 352) and metastatic (n = 208) cervical tumors, 27 patients required PMV and 20 patients underwent reintubation. The incidence rates of PMV and reintubation were 4.82% and 3.57%, respectively. Three variables (all p < 0.05) were independently associated with an increased risk of PMV: Karnofsky Performance Status < 50 compared to ≥ 80, operation duration ≥ 8 h compared to < 6 h, and C4 nerve root encased by the tumor. Longer operative duration and preoperative hypercapnia (all p < 0.05) were independent risk factors for postoperative reintubation, both of which led to longer length of stay (32.6 ± 30.8 vs. 10.7 ± 5.95 days, p < 0.001), with an in-hospital mortality of 17.0%.

CONCLUSION

Our results demonstrate the risk factors for PMV or reintubation after surgery for malignant cervical tumors. Adequate assessment, early detection, and prevention are necessary for this high-risk population.

Upper Extremity Nerve Transfers for Treatment of Nerve Injury After Cervical Spine Surgery: A Single-Center Retrospective Review

PURPOSE

Nerve transfers to restore or augment function after spinal cord injury is an expanding field. There is a paucity of information, however, on the use of nerve transfers for patients having undergone spine surgery. The incidence of neurologic deficit after spine surgery is rare but extremely debilitating. The purpose of this study was to describe the functional benefit after upper extremity nerve transfers in the setting of nerve injury after cervical spine surgery.

METHODS

A single-center retrospective review of all patients who underwent nerve transfers after cervical spine surgery was completed. Patient demographics, injury features, spine surgery procedure, nerve conduction and electromyography study results, time to referral to nerve surgeon, time to surgery, surgical technique and number of nerve transfers performed, complications, postoperative muscle testing, and subjective outcomes were reviewed.

RESULTS

Fourteen nerve transfers were performed in 6 patients after cervical spine surgery. Nerve transfer procedures consisted of a transfer between a median nerve branch of flexor digitorum superficialis into a biceps nerve branch, an ulnar nerve branch of flexor carpi ulnaris into a brachialis nerve branch, a radial nerve branch of triceps muscle into the axillary nerve, and the anterior interosseous nerve into the ulnar motor nerve. Average patient age was 55 years; all patients were male and underwent surgery on their left upper extremity. Average referral time was 7 months, average time to nerve transfer was 9 months, and average follow-up was 21 months. Average preoperative muscle grading was 0.9 of 5, and average postoperative muscle grading was 4.1 of 5 ( P < 0.00001).

CONCLUSIONS

Upper extremity peripheral nerve transfers can significantly help patients regain muscle function from deficits secondary to cervical spine procedures. The morbidity of the nerve transfers is minimal with measurable improvements in muscle function.

The Ultrasonic Bone Scalpel does not Outperform the High-Speed Drill: A Single Academic Experience

BACKGROUND

Spinal decompression and osteotomies are conventionally performed using high-speed drills (HSDs) and rongeurs. The ultrasonic bone scalpel (UBS) is a tissue-specific osteotome that preferentially cuts bone while sparing the surrounding soft tissues. There is ongoing investigation into its ability to optimize peri- and postoperative outcomes in spine surgery. The purpose of this study was to compare the intraoperative metrics and complications during a transition period from HSD to UBS.

METHODS

A single-institution, single-surgeon retrospective analysis was conducted of patients undergoing spine surgery from January 2020 to December 2021. Statistical analyses were performed to detect associations between the surgical technique and outcomes of interest. A P value < 0.05 was considered statistically significant.

RESULTS

A total of 193 patients met the inclusion criteria (HSD, n = 100; UBS, n = 93). Multivariate logistic regression revealed similar durotomy (P = 0.10), nerve injury (P = 0.20), and reoperation (P = 0.68) rates. Although the estimated blood loss (EBL) and length of stay were similar, the operative time was significantly longer with the UBS (192.81 vs. 204.72 minutes; P = 0.03). Each subsequent surgery using the UBS revealed a 3.1% decrease in the probability of nerve injury (P = 0.026) but had no significant effects on the operative time, EBL, or probability of durotomy or reoperation.

CONCLUSIONS

The UBS achieves outcomes on par with conventional tools, with a trend toward a lower incidence of neurologic injury. The expected reductions in EBL and durotomy were not realized in our cohort, perhaps because of a high proportion of revision surgeries, although these might be dependent on surgeon familiarity, among other operative factors. Future prospective studies are needed to validate our results and further refine the optimal application of this device in spine surgery.

Acute complications in open/miss primary and revision thoracolumbar spine surgery: a descriptive study of the most common complications and treatment of choice

PURPOSE

Main question The aim of this study is to describe and analyze the frequency of acute perioperative (intraoperatively and 30 days after) complications of open/MISS thoracolumbar spine surgery. Secondary questions A) Describe the treatment of choice for every kind of complication mentioned. B) Perform a bibliographic search and compare the complications described and their frequency with those studied in the manuscript.

METHODS

A retrospective cohort of 816 patients undergoing spinal surgery over a two year period was analyzed. Acute complications of 59 patients are described whether those with a greater number of levels required longer periods of hospitalization.

RESULTS

The frequency of acute complications was 7.2%. The most common was infection (2.7%), followed by dural tear (1.7%), and screw malpositioning (1%), which is consistent with the current literature. No statistically significant results were observed when comparing the mean length of hospital stay among patients operated on a greater number of levels compared to the rest (P: 0.344; 95% CI: -3.88-10.93).

CONCLUSIONS

The subsidiary patient of spinal surgery is getting older and has more comorbidities, and therefore, has a higher risk of complications. Although there are models predicting the risk of complications, they are not used in routine clinical practice. It would be necessary to unify the main criteria and establish guidelines for risk detection and therapeutic algorithms based on new high-quality studies.

To infer the probability of cervical ossification of the posterior longitudinal ligament and explore its impact on cervical surgery

The ossification of the posterior longitudinal ligament (OPLL) in the cervical spine is commonly observed in degenerative changes of the cervical spine. Early detection of cervical OPLL and prevention of postoperative complications are of utmost importance. We gathered data from 775 patients who underwent cervical spine surgery at the First Affiliated Hospital of Guangxi Medical University, collecting a total of 84 variables. Among these patients, 144 had cervical OPLL, while 631 did not. They were randomly divided into a training cohort and a validation cohort. Multiple machine learning (ML) methods were employed to screen the variables and ultimately develop a diagnostic model. Subsequently, we compared the postoperative outcomes of patients with positive and negative cervical OPLL. Initially, we compared the advantages and disadvantages of various ML methods. Seven variables, namely Age, Gender, OPLL, AST, UA, BMI, and CHD, exhibited significant differences and were used to construct a diagnostic nomogram model. The area under the curve (AUC) values of this model in the training and validation groups were 0.76 and 0.728, respectively. Our findings revealed that 69.2% of patients who underwent cervical OPLL surgery eventually required elective anterior surgery, in contrast to 86.8% of patients who did not have cervical OPLL. Patients with cervical OPLL had significantly longer operation times and higher postoperative drainage volumes compared to those without cervical OPLL. Interestingly, preoperative cervical OPLL patients demonstrated significant increases in mean UA, age, and BMI. Furthermore, 27.1% of patients with cervical anterior longitudinal ligament ossification (OALL) also exhibited cervical OPLL, whereas this occurrence was only observed in 6.9% of patients without cervical OALL. We developed a diagnostic model for cervical OPLL using the ML method. Our findings indicate that patients with cervical OPLL are more likely to undergo posterior cervical surgery, and they exhibit elevated UA levels, higher BMI, and increased age. The prevalence of cervical anterior longitudinal ligament ossification was also significantly higher among patients with cervical OPLL.

Impact of cervical spine pathology on outcomes after total shoulder arthroplasty

BACKGROUND

Cervical spine pathology can affect the supporting muscles and function of the shoulder and contribute to shoulder and arm pain and hence may impact postoperative outcomes following shoulder arthroplasty. The purpose of this study was to evaluate the impact of a history of cervical spine arthrodesis and its timing, before or after total shoulder arthroplasty (TSA), on the outcomes of TSA. Our hypothesis is that a history of cervical arthrodesis (CA) will negatively impact patient outcomes after shoulder arthroplasty.

METHODS

A retrospective analysis was performed on a prospectively collected cohort at a single institution. Anatomic (aTSA) and reverse TSA (rTSA) patients with CA were identified and compared to a cohort of patients without CA (NCA) enrolled in an institutional registry from 2011 to 2020. Demographic characteristics, diagnoses, implant type, range of motion, adverse events, and clinical outcome metric scores (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], Constant, Shoulder Function score, patient satisfaction) were recorded. Outcomes between cohorts were analyzed using conventional statistics as well as stratification by minimal clinically important difference and substantial clinical benefit (SCB) thresholds where applicable.

RESULTS

Of the 573 TSAs evaluated, 48 (20a CA-aTSA and 28 CA-rTSA) had a history of CA and 525 (280 NCA-aTSA and 245 NCA-rTSA) had no history of CA. The CA-TSA (aTSA and rTSA) had lower Constant, ASES, and Shoulder Function scores postoperatively as well as less improvement in active external rotation and an overall lower satisfaction rating (P < .05 for all) compared with NCA-TSA. The adverse event rate in the CA-TSA cohort was higher compared with the NCA-TSA cohort (25% vs. 6.5% [rTSA; P = .004] and 24.5% vs. 11% [aTSA; P = .068]). Optimal cutoff analysis showed that a time from CA to TSA of greater than 1.33 years had a sensitivity of 75.0% and specificity of 75.0% in predicting achievement of SCB for ASES score.

CONCLUSION

The current study demonstrates that patients with a history of CA undergoing shoulder arthroplasty results in lower postoperative functional outcomes, lower satisfaction, and higher rates of postoperative adverse events requiring surgical revision when compared to a cohort without a history of CA. Additionally, the current study demonstrates that a time interval of at least 16 months between CA and shoulder arthroplasty optimizes the chances of achieving SCB for ASES score.

The Role of Intraoperative Neuromonitoring Modalities in Anterior Cervical Spine Surgery

Background: Intraoperative neuromonitoring (IONM) is frequently used during spine surgery to mitigate the risk of neurological injuries. Yet, its role in anterior cervical spine surgery remains controversial. Without consensus on which anterior cervical spine surgeries would benefit the most from IONM, there is a lack of standardized guidelines for its use in such procedures. Purpose: We sought to assess the alerts generated by each IONM modality for 4 commonly performed anterior cervical spinal surgeries: anterior cervical diskectomy and fusion (ACDF), anterior cervical corpectomy and fusion (ACCF), cervical disk replacement (CDR), or anterior diskectomy. In doing so, we sought to determine which IONM modalities (electromyography [EMG], motor evoked potentials [MEP], and somatosensory evoked potentials [SSEP]) are associated with alert status when accounting for procedure characteristics (number of levels, operative level). Methods: We conducted a retrospective review of IONM data collected by Accurate Neuromonitoring, LLC, a company that supports spine surgeries conducted by 400 surgeons in 8 states, in an internally managed database from December 2009 to September 2018. The database was queried for patients who underwent ACCF, ACDF, anterior CDR, or anterior diskectomy in which at least 1 IONM modality was used. The IONM modalities and incidence of alerts were collected for each procedure. The search identified 8854 patients (average age, 50.6 years) who underwent ACCF (n = 209), ACDF (n = 8006), CDR (n = 423), and anterior diskectomy (n = 216) with at least 1 IONM modality. Results: Electromyography was used in 81.3% (n = 7203) of cases, MEP in 64.8% (n = 5735) of cases, and SSEP in 99.9% (n = 8844) of cases. Alerts were seen in 9.3% (n = 671), 0.5% (n = 30), and 2.7% (n = 241) of cases using EMG, MEP and SSEP, respectively. In ACDF, a significant difference was seen in EMG alerts based on the number of spinal levels involved, with 1-level ACDF (6.9%, n = 202) having a lower rate of alerts than 2-level (10.0%, n = 272), 3-level (15.2%, n = 104), and 4-level (23.4%, n = 15). Likewise, 2-level ACDF had a lower rate of alerts than 3-level and 4-level ACDF. A significant difference by operative level was noted in EMG use for single-level ACDF, with C2-C3 having a lower rate of use than other levels. Conclusions: This retrospective review of anterior cervical spinal surgeries performed with at least 1 IONM modality found that SSEP had the highest rate of use across procedure types, whereas MEP had the highest rate of nonuse. Future studies should focus on determining the most useful IONM modalities by procedure type and further explore the benefit of multimodal IONM in spine surgery.

Horner's Syndrome and Lymphocele Following Thyroid Surgery

Horner’s syndrome (HS), caused by lesions of the 3-neuron oculosympathetic nerve pathway (ONP), includes the triad: blepharoptosis, miosis and anhidrosis (ipsilateral with ONP damage). Thyroid−related HS represents an unusual entity underling thyroid nodules/goiter/cancer−HS (T-HS), and post-thyroidectomy HS (Tx-HS). We aim to overview Tx-HS. This is a narrative review. We revised PubMed published, full-length, English papers from inception to November 2022. Additionally, we introduced data on post-thyroidectomy lymphocele/chylous leakage (Tx-L), and introduced a new pediatric case with both Tx-HS and Tx-L. Tx-HS: the level of statistical evidence varies from isolated case reports, studies analyzing the large panel of post-thyroidectomy complications reporting HS among the rarest side effects (as opposite to hypocalcemia), or different series of patients with HS due to various disorders, including T-HS/Tx-HS. Tx-HS is related to benign or malignant thyroid conditions, regardless the type of surgery. A pre-operatory rate of T-HS of 0.14%; a post-operatory rate of Tx-HS between 0.03% and 5% (mostly, 0.2%) are identified; a possible higher risk on endoscopic rather than open procedure is described. Incomplete HS forms, and pediatric onset are identified, too; the earliest identification is after 2 h since intervention. A progressive remission is expected in most cases within the first 2−6 months to one year. The management is mostly conservative; some used glucocorticoids and neurotrophic agents. One major pitfall is an additional contributor factor like a local compression due to post-operatory collections (hematoma, cysts, fistula, Tx-L) and their correction improves the outcome. The prognostic probably depends on the severity of cervical sympathetic chain (CSC) lesions: indirect, mild injury due to local compressive masses, intra-operatory damage of CSC like ischemia and stretching of CSC by the retractor associate HS recovery, while CSC section is irreversible. Other iatrogenic contributors to HS are: intra-operatory manipulation of parathyroid glands, thyroid microwave/radiofrequency ablation, and high-intensity focused ultrasound, and percutaneous ethanol injection into thyroid nodules. Tx-L, rarely reported (mostly <0.5%, except for a ratio of 8.3% in one study), correlates with extended surgery, especially lateral/central neck dissection, and the presence of congenitally—aberrant lymphatic duct; it is, also, described after endoscopic procedures and chest-breast approach; it starts within days after surgery. Typically low-fat diet (even fasting and parental nutrition) and tube drainage are useful (as part of conservative management); some used octreotide, local sealing solutions like hypertonic glucose, Viscum album extract, n-Butyl-2-cyanoacrylate. Re-intervention is required in severe cases due to the risk of lymphorrhoea and chylothorax. Early identification of Tx-HS and Tx-L improves the outcome. Some iatrogenic complications are inevitable and a multifactorial model of prediction is still required, also taking into consideration standardized operatory procedures, skillful intra-operatory manipulation, and close post-operatory follow-up of the patients, especially during modern era when thyroid surgery registered a massive progress allowing an early discharge of the patients.

Alteration of muscle activity during voluntary rehabilitation training with single-joint Hybrid Assistive Limb (HAL) in patients with shoulder elevation dysfunction from cervical origin

Shoulder elevation, defined here as arm raising, being essential for activities of daily living, dysfunctions represent a substantial burden in patients' lives. Owing to the complexity of the shoulder joint, the tightly coordinated muscular activity is a fundamental component, and neuromuscular impairments have devastating effects. A single-joint shoulder type version of the Hybrid Assistive Limb (HAL) allowing motion assistance based on the intention of the user via myoelectric activation has recently been developed, and its safety was demonstrated for shoulder rehabilitation. Yet, little is known about the physiological effects of the device. This study aims to monitor the changes in muscle activity and motion during shoulder HAL rehabilitation in several patients suffering from shoulder elevation dysfunction from cervical radicular origin. 8 patients (6 males, 2 females, mean age 62.4 ± 9.3 years old) with weakness of the deltoid muscle resulting from a damage to the C5 nerve root underwent HAL-assisted rehabilitation. We combined surface electromyography and three-dimensional motion capture to record muscular activity and kinematics. All participants showed functional recovery, with improvements in their Manual Muscle Testing (MMT) scores and range of motion (ROM). During training, HAL decreased the activity of deltoid and trapezius, significantly more for the latter, as well as the coactivation of both muscles. We also report a reduction of the characteristic shrugging compensatory motion which is an obstacle to functional recovery. This reduction was notably demonstrated by a stronger reliance on the deltoid rather than the trapezius, indicating a muscle coordination tending toward a pattern similar to healthy individuals. Altogether, the results of the evaluation of motion and muscular changes hint toward a functional recovery in acute, and chronic shoulder impairments from cervical radicular origin following shoulder HAL rehabilitation training and provide information on the physiological effect of the device.

Analysis of the Risk Factors for C5 Nerve Palsy After Cervical Posterior Open-Door Laminoplasty for Patients with Cervical Spondylotic Myelopathy-From the Perspective of Cervical Sagittal Parameters

OBJECTIVE

This study was performed to explore the sagittal radiological parameters related to the occurrence of C5 nerve palsy after cervical posterior open-door laminoplasty for the patients with cervical spondylotic myelopathy.

METHODS

Sixty-two patients who underwent cervical posterior open-door laminoplasty were reviewed retrospectively from March 2017 to March 2022. The C2-7 Cobb angle, C2-7 sagittal vertex axis, thoracic inlet angle, neck tilt, T1 slope, and encroachment ratio of ossification were measured on X-rays. The enrolled patients were divided into C5 nerve palsy and control groups. Logistic regression was performed to analyze the potential risk factors for the occurrence of C5 nerve palsy. The receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) were used to evaluate the significance of the results and the optimal diagnostic value.

RESULTS

The results of logistic regression showed that only the T1 slope and encroachment ratio were variables that were responsible for C5 nerve palsy (P = 0.024; P = 0.04). The ROC curve analysis for the T1 slope showed that the cutoff value was 21.3° and the AUC was 0.796. The ROC curve analysis for the encroachment ratio revealed that the cutoff value was 0.21 and the AUC was 0.763. Both analyses demonstrated good diagnostic value for C5 nerve palsy.

CONCLUSIONS

The preoperative T1 slope and encroachment ratio were variables that were risk factors for C5 nerve palsy in patients who underwent cervical posterior open-door laminoplasty.

Neurological Complications and Recovery Rates of Patients With Adult Cervical Deformity Surgeries

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

This study aims to report the incidence, risk factors, and recovery rate of neurological complications (NC) in patients with adult cervical deformity (ACD) who underwent corrective surgery.

METHODS

ACD patients undergoing surgery from 2013 to 2015 were enrolled in a prospective, multicenter database. Patients were separated into 2 groups according to the presence of neurological complications (NC vs no-NC groups). The types, timing, recovery patterns, and interventions for NC were recorded. Patients' demographics, surgical details, radiographic parameters, and health-related quality of life (HRQOL) scores were compared.

RESULTS

106 patients were prospectively included. Average age was 60.8 years with a mean of 18.2 months follow-up. The overall incidence of NC was 18.9%; of these, 68.1% were major complications. Nerve root motor deficit was the most common complication, followed by radiculopathy, sensory deficit, and spinal cord injury. The proportion of complications occurring within 30 days of surgery was 54.5%. The recovery rate from neurological complication was high (90.9%), with most of the recoveries occurring within 6 months and continuing even after 12 months. Only 2 patients (1.9%) had continuous neurological complication. No demographic or preoperative radiographic risk factors could be identified, and anterior corpectomy and posterior foraminotomy were found to be performed less in the NC group. The final HRQOL outcome was not significantly different between the 2 groups.

CONCLUSIONS

Our data is valuable to surgeons and patients to better understand the neurological complications before performing or undergoing complex cervical deformity surgery.

Postoperative C5 Palsy Following Cervical Laminectomy With Instrumented Fusion Versus Cervical Laminoplasty With Reconstruction: Single Surgeon and National Inpatient Cohort Analyses

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

The objective of this study was to investigate whether cervical laminectomy with instrumented fusion (LF) and cervical laminoplasty with reconstruction (LP) are associated with different rates C5 palsy (C5P) at 1-month follow-up in a single surgeon and nationally representative cohort.

SUMMARY OF BACKGROUND DATA

LF and LP both carry a well-known risk of nerve root injury that most commonly presents as C5P which can reduce patient satisfaction, patient function, and impede patient recovery. The procedure type that is more frequently associated with C5P remains largely unclear.

METHODS

We identified patients undergoing primary LF or LP procedures for the treatment of cervical myelopathy in both a single-surgeon series cohort (2004-2018; Mount Sinai Hospital) and a nationally representative cohort drawn from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database (2006-2017). For the single-surgeon cohort, C5P within 1 month of surgery was recorded. For the NSQIP cohort, peripheral nerve injury (PNI) within 1 month of surgery was recorded and used as a proxy for C5P. Postoperative complications including C5P were compared between cohorts. Multivariable logistic regression was used to evaluate the association between procedure type and postoperative C5P or PNI.

RESULTS

Without adjusting for covariates, LF patients had a higher rate of 1-month C5P in the single-surgeon cohort (8% vs. 0%, P=0.01). An adjusted odds ratio could not be obtained due to the absence of C5P in the LP group. In the national cohort, LP patients had a significantly higher rate of 1-month PNI on unadjusted analysis (11% vs. 16%, P<0.001). After adjusting for covariates, we found no significant difference in odds of 1-month PNI between LF and LP (adjusted odds ratio=0.84, P=0.07).

CONCLUSIONS

Overall, the single-surgeon series suggest that cervical LF is associated with significantly higher rates of postoperative C5P as compared with LP. These findings are not corroborated by nationally representative data, which showed no difference in PNI rates between LF and LP. A surgeon's training and experience likely contribute to which procedure has a higher propensity for a C5P as a complication. Regardless, both LF and LP patients should be closely monitored for new-onset C5P during follow-up visits.

LEVEL OF EVIDENCE

Level III.

Systematic Review: Applications of Intraoperative Ultrasound in Spinal Surgery

BACKGROUND

Due to increased practicality and decreased costs and radiation, interest has risen for intraoperative ultrasound (iUS) in spinal surgery applications; however, few studies have provided a robust overview of its use in spinal surgery. We synthesize findings of existing literature on usage of iUS in navigation, pedicle screw placement, and identification of anatomy during spinal interventions.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized in this systematic review. Studies were identified through PubMed, Scopus, and Google Scholar databases using the search string. Abstracts mentioning iUS in spine applications were included. Upon full-text review, exclusion criteria were implemented, including outdated studies or those with weak topic relevance or statistical power. Upon elimination of duplicates, multi-reviewer screening for eligibility, and citation search, 44 manuscripts were analyzed.

RESULTS

Navigation using iUS is safe, effective, and economical. iUS registration accuracy and success is within clinically acceptable limits for image-guided navigation (Table 2). Pedicle screw instrumentation with iUS is precise with a favorable safety profile (Table 2). Anatomical landmarks are reliably identified with iUS, and surgeons are overwhelmingly successful in neural or vascular tissue identification with iUS modalities including standard B mode, doppler, and contrast-enhanced ultrasound (CE-US) (Table 3). iUS use in traumatic reduction of fractures properly identifies anatomical structures, intervertebral disc space, and vasculature (Table 3).

CONCLUSION

iUS eliminates radiation, decreases costs, and provides sufficient accuracy and reliability in identification of anatomical and neurovascular structures in various spinal surgery settings.

Iatrogenic lesions of the peripheral nervous system in orthopaedic surgery and traumatology procedures

OBJECTIVE

To describe iatrogenic lesions of the peripheral nervous system and their relationship with different orthopaedic and traumatological procedures, through their assessment by means of electromyographic study.

MATERIAL AND METHODS

Retrospective descriptive study of the electromyographies performed in the clinical neurophysiology service of the Hospital General Universitari de Castelló between July 2015 and March 2019, recovering those in which the aetiology was diagnosed as iatrogenic in relation to surgical procedures and analysing those that were initiated after orthopaedic and traumatological procedures.

RESULTS

Of the total number of electromyographies reviewed, 1.37% corresponded to iatrogenic surgical lesions and 55.1% of these were secondary to orthopaedic surgery and traumatology procedures, the incidence in relation to the procedures performed was 0.65%. The most frequent locations related to injuries were the lumbar spine, hip and hand/wrist. Injuries due to postural causes not directly related to the surgical field are noteworthy.

CONCLUSION

Iatrogenic injuries to the peripheral nervous system after orthopaedic surgery and traumatology procedures are infrequent, but given their mechanism of injury and the high severity of most of them, it would be advisable to implement corrective mechanisms to reduce their incidence.

LEVEL OF EVIDENCE

IV.

Cervical laminoplasty with unilateral C4-5 foraminotomy: Technical note and case series

OBJECTIVE

The open-door laminoplasty technique is widely used in the treatment of multilevel cervical myelopathy. Despite the satisfactory functional and radiological results of this technique, postoperative C5 palsy is still a severe and disabling complication with a variable incidence in the literature. The objective of this article is to describe and demonstrate the surgical technique step by step with the addition of unilateral C4-5 foraminotomy and to evaluate the results obtained to date, with special emphasis on C5 palsy.

MATERIAL AND METHODS

Retrospective study of 20 patients operated on for cervical myelopathy using the "extended" laminoplasty technique, which is described step by step.

RESULTS

Between January 2013 and April 2019, 20 patients were operated on using the extended laminoplasty technique. Only one patient (5%) presented postoperative C5 palsy. The postoperative recovery rate of the modified JOA (Japanese Orthopaedic Association) score was 54.5%, similar to that observed in other series.

CONCLUSION

The extended cervical laminoplasty technique with unilateral C4-5 foraminotomy was developed and demonstrated for the prevention of C5 palsy. The results were analysed and an incidence of C5 palsy coinciding with the lowest percentage reported in the literature was obtained. A prospective randomised study would be useful to assess the role of preventive unilateral C4-5 foraminotomy.

Prediction of the risk of C5 palsy after posterior laminectomy and fusion with cervical myelopathy using a support vector machine: an analysis of 184 consecutive patients

Background

This study aimed to predict C5 palsy (C5P) after posterior laminectomy and fusion (PLF) with cervical myelopathy (CM) from routinely available variables using a support vector machine (SVM) method.

Methods

We conducted a retrospective investigation based on 184 consecutive patients with CM after PLF, and data were collected from March 2013 to December 2019. Clinical and imaging variables were obtained and imported into univariable and multivariable logistic regression analyses to identify risk factors for C5P. According to published reports and clinical experience, a series of variables was selected to develop an SVM machine learning model to predict C5P. The accuracy (ACC), area under the receiver operating characteristic curve (AUC), and confusion matrices were used to evaluate the performance of the prediction model.

Results

Among the 184 consecutive patients, C5P occurred in 26 patients (14.13%). Multivariate analyses demonstrated the following 4 independent factors associated with C5P: abnormal electromyogram (odds ratio [OR] = 7.861), JOA recovery rate (OR = 1.412), modified Pavlov ratio (OR = 0.009), and presence of C4C5 foraminal stenosis (OR = 15.492). The SVM model achieved an area under the receiver operating characteristic curve (AUC) of 0.923 and an ACC of 0.918. Additionally, the confusion matrix showed the classification results of the discriminant analysis.

Conclusions

The designed SVM model presented satisfactory performance in predicting C5P from routinely available variables. However, future external validation is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02476-5.

Circumferential Operations of the Cervical Spine

Generally, a combined anterior and posterior cervical approach is associated with significant morbidity since it requires an extended operative time, greater intraoperative blood loss, and both anterior- and posterior-related surgical complications. However, there are some instances where a circumferential cervical fusion can be advantageous. Our objective is to discuss the indications for circumferential cervical spine procedures. A narrative review of the literature was performed. We include the indications for circumferential cervical approaches of the senior author (KDR). Indications for circumferential approaches include: (1) high-risk patients for pseudoarthrosis, (2) cervical deformity (e.g., degenerative, posttraumatic, cervicothoracic kyphosis), (3) cervical spine metastases (especially those with multilevel involvement), (4) cervical spine infection, (5) unstable cervical trauma, (6) movement disorders and cerebral palsy, (7) Multiply operated patient (especially postlaminectomy kyphosis and patients with massive ossification of the posterior longitudinal ligament), and when (8) early fusion is desirable. Circumferential procedures may be useful in many different cervical spine conditions requiring surgery. Despite its advantages, particularly with reducing the risk for pseudarthrosis, the benefits of a combined approach must be weighed against the risks associated with a dual approach. With appropriate preoperative planning, intraoperative decision-making, and surgical techniques, excellent clinical outcomes can be achieved.

Iatrogenic lesions of the peripheral nervous system in orthopaedic surgery and traumatology procedures

OBJECTIVE

To describe iatrogenic lesions of the peripheral nervous system and their relationship with different orthopaedic and traumatological procedures, through their assessment by means of electromyographic study.

MATERIAL AND METHODS

Retrospective descriptive study of the electromyographies performed in the clinical neurophysiology service of the Hospital General Universitari de Castelló between July 2015 and March 2019, recovering those in which the aetiology was diagnosed as iatrogenic in relation to surgical procedures and analysing those that were initiated after orthopaedic and traumatological procedures.

RESULTS

Of the total number of electromyographies reviewed, 1.37% corresponded to iatrogenic surgical lesions and 55.1% of these were secondary to orthopaedic surgery and traumatology procedures, the incidence in relation to the procedures performed was 0.65%. The most frequent locations related to injuries were the lumbar spine, hip and hand/wrist. Injuries due to postural causes not directly related to the surgical field are noteworthy.

CONCLUSION

Iatrogenic injuries to the peripheral nervous system after orthopaedic surgery and traumatology procedures are infrequent, but given their mechanism of injury and the high severity of most of them, it would be advisable to implement corrective mechanisms to reduce their incidence.

LEVEL OF EVIDENCE

IV.

Cervical laminoplasty with unilateral C4-5 foraminotomy: Technical note and case series

OBJECTIVE

The open-door laminoplasty technique is widely used in the treatment of multilevel cervical myelopathy. Despite the satisfactory functional and radiological results of this technique, postoperative C5 palsy is still a severe and disabling complication with a variable incidence in the literature. The objective of this article is to describe and demonstrate the surgical technique step by step with the addition of unilateral C4-5 foraminotomy and to evaluate the results obtained to date, with special emphasis on C5 palsy.

MATERIAL AND METHODS

Retrospective study of 20 patients operated on for cervical myelopathy using the "extended" laminoplasty technique, which is described step by step.

RESULTS

Between January 2013 and April 2019, 20 patients were operated on using the extended laminoplasty technique. Only one patient (5%) presented postoperative C5 palsy. The postoperative recovery rate of the modified JOA (Japanese Orthopaedic Association) score was 54.5%, similar to that observed in other series.

CONCLUSION

The extended cervical laminoplasty technique with unilateral C4-5 foraminotomy was developed and demonstrated for the prevention of C5 palsy. The results were analysed and an incidence of C5 palsy coinciding with the lowest percentage reported in the literature was obtained. A prospective randomised study would be useful to assess the role of preventive unilateral C4-5 foraminotomy.

The anatomical mechanism of C5 palsy after expansive open-door laminoplasty

BACKGROUND

Postoperative C5 palsy is not an uncommon complication in patients who undergo expansive open-door laminoplasty. However, the etiology is unclear and likely multifactorial. Nerve root lesions and spinal cord lesions have been previously proposed theories.

PURPOSE

To investigate the anatomical mechanism of postoperative C5 palsy after cervical expansive open-door laminoplasty.

STUDY DESIGN

A dissection-based study of eight embalmed human cadavers.

METHODS

The anatomy was studied in eight whole cervical cadavers (three females, five males), prepared with formaldehyde, whose ages at the time of death ranged from 54 to 78 years. Dissection was performed on the intervertebral foramen and spinal canal. In the C3-C7 of the cervical vertebra, the extraforaminal ligaments and the meningovertebral ligaments were observed. The length, width, and thickness of the ligaments were measured with a Vernier caliper. After an expansive open-door laminoplasty was performed, the shape of the dural sac was changed, and displacement of the nerve root was observed. In addition, the lengths of the anterior rootlets were measured. This study has been supported by grants from Science and Technology Planning Project of Guangdong Province (CN) (Grant No. 2017B020210010) without potential conflict of interest-associated biases in the text of the paper.

RESULTS

One hundred seventy-seven extraforaminal ligaments were found to connect the spinal nerve to the surrounding structures. After an expansive open-door laminoplasty was performed, posterior distension of the dural sac and movement of the spinal cord and nerve root were found. The spinal cord was closely attached to the ligamentum flavum by meningovertebral ligaments. In addition, the length of the C5 intradural rootlets (5.81-10.59 mm) was the shortest among the vulnerable segments.

CONCLUSION

Traction on and posterior movement of the extradural roots may be the main pathologic mechanism of postoperative C5 palsy when expansive open-door laminoplasty is performed. The meningovertebral ligaments and extraforaminal ligaments might play an important role in the occurrence of postoperative C5 palsy.

CLINICAL SIGNIFICANCE

This study provides clinicians with a more detailed understanding of the anatomic structure and potential mechanism of C5 palsy. Consideration of the meningovertebral ligaments and the intervertebral foramen may provide new directions for reducing the incidence of this complication.