Complications associated with prone positioning in elective spinal surgery

Agreement between non-invasive and invasive arterial blood pressure during surgery in the prone position: an error grid analysis

PURPOSE

Prone position has recently gained renewed importance as a treatment for acute respiratory distress syndrome and spine and brain surgeries. Our study aimed to perform an error grid analysis to examine the clinical discrepancies between arterial blood pressure (ABP) and non-invasive blood pressure (NIBP) in the prone position and to investigate the risk factors influencing these differences.

METHODS

Error grid analysis was performed retrospectively on 1389 pairs of 100 consecutive prone positioning cases. This analysis classifies the difference between the two methods into five clinically relevant zones, from "no risk" to "dangerous risk". Additionally, multivariable ordinal logistic regression analysis was conducted to evaluate the relationship between the risk zones of mean blood pressure (MBP), as classified by error grid analysis and the covariate of interest.

RESULTS

Error grid analysis showed that the proportions of measurement pairs in risk zones A-E for systolic blood pressure were 96.8%, 3.2%, 0.1%, 0%, and 0%, respectively. In contrast, the MBP proportions were 74.0%, 25.1%, 0.9%, 0.1%, and 0%. Multivariable ordinal logistic regression analysis revealed that the position of arms (next to the head) was a significant factor (adjusted odds ratio: 4.35, 95% CI: 2.38-8.33, P < 0.001).

CONCLUSION

Error grid analysis revealed a clinically unacceptable discrepancy between ABP and NIBP for MBP during prone positioning surgery. The position of the arms next to the head was associated with increased clinical discrepancy between the two MBP measurement methods.

Spinal Robotics in Single-Position Lateral Surgery: A Narrative Review of Key Concepts and Considerations

Anterior column realignment via anterior, oblique, or lateral lumbar interbody fusion is increasingly recognized as a powerful mechanism for indirect decompression and sagittal realignment in flexible deformity. Single-position lateral surgery is a popular variation that places patients in the lateral decubitus position, allowing concomitant placement of lateral interbodies and posterior segmental instrumentation without the need for repositioning the patient. The addition of robotics to this technique can help to overcome ergonomic limitations of the placement of pedicle screws in the lateral decubitus position; however, its description in the literature is relatively lacking. In this review we aim to discuss the indications, advantages, and pitfalls of this approach.

Single-position oblique lumbar interbody fusion with navigation: improved efficiency and screw accuracy compared to dual-position with fluoroscopy

Dual-position oblique lumbar interbody fusion with fluoroscopy (D-OLIF) requires repositioning the patient to a prone position for pedicle screw insertion. Recently, single-position surgery with navigation has been introduced. However, there are concerns regarding pedicle screw accuracy and achieving appropriate sagittal balance in single-position OLIF with navigation (S-OLIF). The purpose of this study is to evaluate the clinical and radiological outcomes of S-OLIF compared to D-OLIF. A retrospective analysis was conducted on 102 patients who underwent single-level OLIF at a single institution. The patients were divided into two groups: 55 in the S-OLIF group and 47 in the D-OLIF group. The numeric rating scale for back and leg, Oswestry disability index, and walking distance improvements showed no significant difference. However, the EuroQol 5-dimension 5-level index showed higher improvement in the S-OLIF (P = 0.029). The segmental lordosis, lumbar lordosis, and C7 sagittal vertical axis showed no significant difference. S-OLIF had significantly fewer cases of pedicle screw malposition (P = 0.045). Additionally, the surgery time was shorter in the S-OLIF (P = 0.002). In conclusion, S-OLIF exhibited clinical and radiological outcomes comparable to D-OLIF, with the added advantages of reduced surgery time and enhanced accuracy in pedicle screw placement.

Impact of Supine versus Prone Positioning on Segmental Lumbar Lordosis in Patients Undergoing ALIF Followed by PSF: A Comparative Study

Background: Anterior lumbar interbody fusion (ALIF) and posterior spinal fusion (PSF) play pivotal roles in restoring lumbar lordosis in spinal surgery. There is an ongoing debate between combined single-position surgery and traditional prone-position PSF for optimizing segmental lumbar lordosis. Methods: This retrospective study analyzed 59 patients who underwent ALIF in the supine position followed by PSF in the prone position at a single institution. Cobb angles were measured preoperatively, post-ALIF, and post-PSF using X-ray imaging. One-way repeated measures ANOVA and post-hoc analyses with Bonferroni adjustment were employed to compare mean Cobb angles at different time points. Cohen's d effect sizes were calculated to assess the magnitude of changes. Sample size calculations were performed to ensure statistical power. Results: The mean segmental Cobb angle significantly increased from preoperative (32.2 ± 13.8 degrees) to post-ALIF (42.2 ± 14.3 degrees, Cohen's d: -0.71, p < 0.0001) and post-PSF (43.6 ± 14.6 degrees, Cohen's d: -0.80, p < 0.0001). There was no significant difference between Cobb angles after ALIF and after PSF (Cohen's d: -0.10, p = 0.14). The findings remained consistent when Cobb angles were analyzed separately for single-screw and double-screw ALIF constructs. Conclusions: Both supine ALIF and prone PSF significantly increased segmental lumbar lordosis compared to preoperative measurements. The negligible difference between post-ALIF and post-PSF lordosis suggests that supine ALIF followed by prone PSF can be an effective approach, providing flexibility in surgical positioning without compromising lordosis improvement.

Treatment approach for coexisting chest wall fractures and unstable thoracolumbar spine fractures in polytrauma patients requiring prone spine surgery

Concomitant chest wall fractures (sternal and/or rib fractures) with unstable thoracolumbar fractures that require surgical fixation are rare but highly morbid injuries that mandate a multidisciplinary approach to treatment. There is limited evidence in the literature regarding optimal timing and order of surgical fixation of these patients with multiple injuries. Here, we present our experience with two patients at a single institution that demonstrates the challenges that present with this patient population. We advocate for earlier fixation of the chest wall fractures in the appropriately indicated patients, prior to prone positioning for spinal fixation.

Effects of Anesthetic Choice on the Incidence of Transcranial-Motor Potential-Induced Oral Trauma

Transcranial motor-evoked potentials (TcMEPs) play an integral role in assessing motor tract function in surgical procedures where motor function is at risk. However, transcranial stimulation creates a risk for oral trauma. Several studies have reported on distinct factors that can influence the rate of TcMEP-induced oral trauma, but little is known about how an anesthetic regimen can influence this rate. In this retrospective review, we investigated the incidence of oral injury under total intravenous anesthesia (TIVA) and balanced anesthesia in 66,166 cases from 2019 to 2021. There were 295 oral injuries in our sample, yielding an incidence of 0.45%, which is in line with ranges reported in the literature. A total of 222 of the injured patients were sedated with balanced anesthesia, while the remaining 73 were under TIVA anesthetics. This difference in distribution was statistically significant (p < 0.0002). Our findings suggest TIVA is associated with lower risk of oral trauma when TcMEPs are monitored, thereby improving patient safety.

Prediction of tissue deformation based on mechanical and physiological factors in the prone position during surgery

AIM

This study aimed to predict tissue deformation based on the pressure applied while lying in the prone position and physiological factors.

METHODS

Healthy volunteers were instructed to lie on mattresses of four different hardness levels (50, 87.5, 175, and 262.5 N). The order in which the mattresses were used was randomized per participant. Pressure at the iliac crests was measured using a pressure mapping sensor sheet. Participants were placed in the prone position for 10 min, with pressure data used from the latter 5 min. For the tissue deformation at the iliac crests, our previous study data were used. Multiple regression analysis was used to identify predictive mechanical and physiological factors.

RESULTS

The distance between the left and right greater trochanters, maximum interface pressure and age were significant predictors for compression of the skin and soft tissue. Significant predictors of internal soft tissue displacement were the distances between the left and right anterior superior iliac spines and greater trochanters. No factors predicted skin surface displacement.

CONCLUSIONS

Our study provided predictive factors that may be measured easily in a clinical setting to reduce the risk of pressure ulcers during surgery in the prone position.

Evaluating the Effects of a General Anesthesia and Prone Position Nursing Checklist and Training Course on Posterior Lumbar Surgery: A Randomized Controlled Trial

BACKGROUND

While general anesthesia in the prone position is one of the most utilized surgical positions, it predisposes to multiple types of complications. Existing studies on this topic are mostly literature reviews or focus on solving one complication, which limits their clinical use.

OBJECTIVE

The aims of the study were to evaluate the effectiveness of a 22-item general anesthesia and prone position nursing checklist and specific training course at preventing complications related to general anesthesia in the prone position.

DESIGN

The study used a randomized controlled trial.

SETTINGS AND PARTICIPANTS

Convenience sampling was used to recruit patients who underwent general anesthesia during posterior lumbar surgery from July 2021 to December 2021 at the Run Run Shaw Hospital, Zhejiang University School of Medicine Hospital.

METHODS

Patients involved in the study were randomly assigned to the control (standard general anesthesia and prone position care) or experimental group (general anesthesia and prone position nursing checklist combined with specific training course in addition to standard general anesthesia and prone position care). Outcomes were pressure injuries, peripheral nerve injuries, ocular complications, and length of stay (LOS). Patient satisfaction, Numeric Pain Rating Scale (NRS) and the Oswestry Disability Scale were also measured.

RESULTS

Compared with the control group, pressure injury, brachial plexus injury, and two ocular findings (foreign body sensation and blurry vision) were significantly less common in the intervention group ( P ≤ 0.01). Participants who received standard general anesthesia and prone position care had lower self-reported satisfaction than those managed with the general anesthesia and prone position nursing checklist plus specific training course ( P = 0.002). The checklist-based intervention also significantly reduced LOS ( P = 0.000) and NRS ( P = 0.000).

CONCLUSIONS

The intervention group had significant fewer general anesthesia in the prone position-related complications, improved satisfaction, reduced LOS, and lower NRS. These findings suggest that a general anesthesia and prone position nursing checklist in addition to a specific training course are beneficial to standardizing prone position nursing care during posterior lumbar surgery.

Comparison of standard and modified prone positioning for lateral lumbar spine fusion: a feasibility study to reduce lumbar plexus injury

Single-prone-lateral (PL) positioning is a new technique that allows for simultaneous anterior and posterior lumbar spine surgery. However, there is a concern regarding the risk of lumbar plexus injury in PL positioning. This study compared the risk of lumbar plexus damage and the overall safety profile of a modified PL (mPL) position to the standard PL (sPL) position for lateral lumbar spine fusion surgery. A crossover soft cadaveric study was conducted with two raters examining the comparative outcomes of position A: sPL and position B: mPL. The mPL position differs from the sPL position in that the ipsilateral arm is placed at the side of the body rather than above the head. To assess positive results (no lumbar plexus injury) between positions A and B, a mixed effects logistic regression model was utilized. The odds ratio of a good result between positions B and A was also determined. The odds ratio of the favorable outcome between position B and A was 1.77, indicating significantly higher odds of a favorable outcome in the modified position B than in the control or position A. The mPL positioning outperformed the sPL positioning in terms of safety and efficacy for lateral lumbar spine fusion. The mPL positioning may reduce the risk of lumbar plexus injury by allowing for a more direct approach to the lumbar spine and by avoiding excessive stretching of the lumbar plexus.

The Utility and Appropriateness of Single-Position Circumferential Lumbar Interbody Fusion Using O-Arm-Based Navigation in the Novel Oblique Position

PURPOSE

Single-position surgery with patients in a lateral position, which involves inserting percutaneous pedicular screws (PPS) and lateral interbody fusion (LIF) to avoid changing the position, has been reported. The purpose of the present study was to evaluate the utility and appropriateness of single-position LIF-PPS using O-arm-based navigation in the innovative oblique position.

METHODS

This study involved a retrospective analysis of 92 consecutive patients with lumbar spondylolisthesis who underwent LIF-PPS using O-arm-based navigation. Thirty-five subjects demonstrated surgery with repositioning, as well as 24 in the lateral decubitus position, and 33 in the oblique during PPS, where the position was changed to the lateral decubitus position using bed rotation without resetting. We compared these three groups in terms of the surgery time, blood loss, and the accuracy of the screw placement.

RESULTS

The operative time was significantly shorter in the single-position surgery, both in the lateral and oblique positions, compared to surgery in a dual position. The blood loss was significantly increased in the lateral position compared to the dual and oblique positions. The screw trajectory angle on the downside was significantly smaller in the lateral position, and the accuracy of the screw placement on the downside was significantly lower in the lateral position compared to the dual and oblique positions.

CONCLUSION

Single-position surgery could reduce the average surgery time by about 60 min. The present study indicated the oblique position during PPS insertion might make single-position surgery more useful to improve the accuracy of PPS on the downside, with less blood loss.

Post-kyphoplasty myelopathy, an unusual presentation of post-operative anterior spinal cord infarct: A case report

Highlights

To discuss a rare complication of prone positioning during kyphoplasty.To compare two rare causes of anterior spinal artery infarct secondary to prone positioning: Surfer Myelopathy and post-kyphoplasty myelopathy.

Background

Kyphoplasty is a common, minimally invasive procedure performed to restore vertebral body structure and relieve pain in insufficiency fractures that are refractory to conservative treatments. Complications are infrequent, but typically arise from epidural hematoma, cement embolism, or cement extravasation causing stenosis within the spinal canal or neural foramina. In this case, we discuss a rare complication involving a spinal cord infarct developing several levels above the level of intervention due to compression of the anterior spinal artery.

Case presentation

A 71-year-old female with kyphotic deformity and midthoracic compression fractures underwent a procedurally uneventful T12 kyphoplasty. Pre-procedure MRI demonstrated T12 superior endplate compression deformity with mild retropulsion of the superior endplate. Chronic T6 and T8 compression fractures with kyphotic deformity were also seen. Shortly after the procedure, she developed right leg pain and numbness progressing to profound weakness. She was taken immediately for CT scan of the thoracolumbar spine which was negative for cement extravasation, and subsequent MRI was negative for epidural hematoma. The MRI did show a peculiar finding of spinal cord infarct from T8 to the conus with punctate hemorrhage at T11.

Conclusions

It is postulated that the incomplete cord infarct in this patient occurred due to compression of the anterior spinal artery or radicular arteries during positioning in the setting of kyphotic deformity and posterior osteophyte. The dysmorphic changes seen at T8 may have behaved similarly to a disc herniation in compressing the spinal artery in a prone position.

Upper Extremity Neuropathies Following Severe COVID-19 Infection: A Multicenter Case Series

OBJECTIVE

The purpose of the study is to examine presentation, injury patterns, and clinical course, for COVID-19-related peripheral nerve injury following mechanical ventilation.

METHODS

A multicenter retrospective study of patients with COVID-19 complicated by acute respiratory distress syndrome (ARDS) that required mechanical ventilation was undertaken. Patient records were reviewed for intensive care unit and intubation characteristics, prone or lateral decubitus positioning, and the onset of neuropathy diagnosis.

RESULTS

Between September 2020 and January 2022, 11 patients were diagnosed with peripheral neuropathy, including 9 with brachial plexopathy following COVID-19 infection. Each patient developed ARDS requiring mechanical ventilation for a median of 39 days. Six patients (54.5%) underwent prone positioning and 1 lateral decubitus. Neuropathies involved 5 brachial pan-plexopathies, 2 incomplete brachial plexopathies, 2 lower trunk plexopathies, 1 radial neuropathy, and 1 bilateral ulnar neuropathy. At a mean follow-up of 10.2 months, patients with brachial pan-plexopathies demonstrated signs of reinnervation proximally, and 1 resolved to a radial mononeuropathy; however, the majority have demonstrated minimal clinical improvements.

CONCLUSIONS

Our series demonstrates that peripheral neuropathies and especially brachial plexopathies have occurred following mechanical ventilation for ARDS-related COVID-19 infections. Contrary to prior COVID-19 studies, only 54.5% of these patients underwent prone positioning. Aside from a traumatic disturbance of prone positioning, the increased incidence of neuropathy may involve an atraumatic effect of COVID-19 via direct invasion of nerves, autoantibody targeting of nervous tissue, or hypercoagulation-induced microthrombotic angiopathy.

The ideal patient positioning in spine surgery: a preventive strategy

Patient positioning on the surgical table is a critical step in every spine surgery. The most common surgical positions in spine surgery are supine, prone and lateral decubitus. There are countless lesions that can occur during spine surgery due to patient mispositioning. Ulnar nerve and brachial plexus injuries are the most common nerve lesions seen in malpositioned patients. Devastating complications due to increased intraocular pressure or excessive abdominal pressure can also occur in prone decubitus and are real concerns that the surgical team must be aware of. All members of the surgical team (including surgeons, anesthesiologists and nurses) should know how to correctly position the patient, identify possible positioning errors and know how to avoid them in order to prevent postoperative morbidity. This work pretends to do a review of the most common positions during spine surgery, alert to errors that can happen during the procedure and how to avoid them.

The value of intraoperative neurophysiological monitoring during positioning in pediatric scoliosis correction: A case report

Introduction

Prone position during posterior spine surgery can represent a potentially risky procedure for the nervous system. Infrequent injuries due to prone positioning consist of subtle spinal cord infarction or myelopathy that can be promptly detected by intraoperative neurophysiological monitoring (IONM), if applied in this phase of surgery. Here, we report a case that stresses the value of IONM even in detecting spinal positioning-related neurological complications during kyphoscoliosis correction.

Case presentation

A 3-year-old child with a severe thoracic kyphoscoliosis with the angle in the tract T5-T6 underwent an early treatment of scoliosis with growing rods. Before instrumentation or the reduction maneuver, lower limb somatosensory and motor responses disappeared. The patient was repositioned with neck and chest in a more protective position and neuromonitoring signals returned to baseline. The surgery could be completed and the patient had no postoperative neurologic or vascular deficits.

Conclusion

Our findings suggest the importance of extending neuromonitoring in the early phases of anesthesia induction and patient positioning during corrective spinal deformity surgery.

Acute compartment syndrome of the contralateral thigh following reconstructive shoulder surgery done for multidirectional shoulder instability in lateral decubitus position

A man in his early 40s had revision reconstructive surgery on his left shoulder while in a right lateral decubitus position. The prolonged surgery (7 hours) caused acute compartment syndrome (ACS) in the contralateral (right) thigh. Moderate pain and swelling of the contralateral thigh ('well limb') was first noted in the recovery room. After progression to severe swelling and numbness in his right toes, fasciotomies of the right thigh were performed, confirming ACS. Thirteen months later he returned to his prior work without lower extremity discomfort or limitations, and he reported a good result from the revision shoulder surgery. Non-traumatic ACS of a well limb is a rare complication of surgery performed in the lateral decubitus position. We suggest that moving the patient temporarily, or to a new position (eg, beach chair), should be considered when the duration of surgery approaches 4.5 hours.

Percutaneous nephrolithotomy in horseshoe kidney: comparing ultrasound-guided access in flank position with conventional fluoroscopic-guided in prone position

We conducted this study to compare radiation-free US-guided percutaneous nephrolithotomy (PNL) in the flank position with conventional PNL in the prone position for the treatment of renal stones in patients with horseshoe kidneys. In a retrospective study, 14 HSK patients that were treated with conventional fluoroscopy-guided PNL in the prone position (group A) were compared with twenty-four HSK patients that were treated US-guided PNL in the flank position (group B). Data on baseline characteristics, percentage of successful entries, stone-free rate, duration of admission and complication rate were obtained from data registry. The average duration of the operation was 57.6 min in group B, which was statistically less than group A with 65.9 min (P = 0.001). Access time varied from 10 to 32.4 min (mean = 17.1 min) in group A and 5-29.5 min (mean = 10.9 min) in group B (P < 0.001). Access length had a significant relation to the surgery method so PNL with US-guided had less access length (P = 0.002). There was no significant relationship between the surgery guide and the residual stone rate (P = 0.6). Hemoglobin decrease (P = 0.5), hospitalization duration (P = 0.5) and need for blood transfusion (P value = 0.6) were not statistically different between the two groups. PNL with US guidance in flank position is a safe and effective technique in HSK patients and is associated with fewer complications than the traditional approach as well as reduced operating time, radiation exposure, and its complications.

Comprehensive Perioperative Approach to Complex Spine Deformity Management

OBJECTIVE

Study perioperative strategies for optimizing neuroprotection in complex spine deformity correction surgery.

METHODS

We report the case of a patient with severe lumbar dextroscoliosis, thoracolumbar junction hyperkyphosis with a 40-degree Cobb angle levoconvex scoliosis who underwent spinal deformity correction with loss of neuromonitoring during surgery. We performed a literature review on perioperative management of complex spine deformity.

RESULTS

A 50-year-old man presented with lumbar pain and right L4 radiculopathy. Surgical intervention for deformity correction and decompression was indicated with T4-L4 posterior instrumentation L2/L3 and L3/L4 transforaminal lumbar interbody fusion. Surgery was aborted due to the loss of neuromonitoring. Postsurgery, the patient had left sensory deficit and the neurocritical care team clinically suspected and deduced the anatomic location of the spinal cord compression. Magnetic resonance imaging confirmed a T10-T11 hyperintensity suggestive of cord ischemia due to osteophyte compressing the spinal cord. The patient underwent a second corrective surgery with no intraoperative events and has no long-term neurological sequela.

CONCLUSIONS

This case illustrates that a comprehensive perioperative approach and individualized risk factor assessment is useful in complex spine deformity surgery. Further research is needed to determine how this individualized comprehensive approach can lead to intraoperative and postoperative countermeasures that improved spine surgery outcomes.

LEVEL OF EVIDENCE

Level V.

Gravitational Dose‐Response Curves for Acute Cardiovascular Hemodynamics and Autonomic Responses in a Tilt Paradigm

Background

The cardiovascular system is strongly dependent on the gravitational environment. Gravitational changes cause mechanical fluid shifts and, in turn, autonomic effectors influence systemic circulation and cardiac control. We implemented a tilt paradigm to (1) investigate the acute hemodynamic response across a range of directions of the gravitational vector, and (2) to generate specific dose‐response relationships of this gravitational dependency.

Methods and Results

Twelve male subjects were tilted from 45° head‐up tilt to 45° head‐down tilt in 15° increments, in both supine and prone postures. We measured the steady‐state hemodynamic response in a range of variables including heart rate, stroke volume, cardiac output, oxygen consumption, total peripheral resistance, blood pressure, and autonomic indices derived from heart rate variability analysis. There is a strong gravitational dependence in almost all variables considered, with the exception of oxygen consumption, whereas systolic blood pressure remained controlled to within ≈3% across the tilt range. Hemodynamic responses are primarily driven by differential loading on the baroreflex receptors, combined with differences in venous return to the heart. Thorax compression in the prone position leads to reduced venous return and increased sympathetic nervous activity, raising heart rate, and systemic vascular resistance while lowering cardiac output and stroke volume.

Conclusions

Gravitational dose‐response curves generated from these data provide a comprehensive baseline from which to assess the efficacy of potential spaceflight countermeasures. Results also assist clinical management of terrestrial surgery in prone posture or head‐down tilt positions.

Upper Extremity Monoplegia following Prone Surrender Position for Spinal Surgery

Background Secondary peripheral nerve injuries remain a significant perioperative problem due to patient positioning and contribute to reduced patient quality of life and exacerbated professional liability. Comorbidities and concomitant lesions can further elicit these injuries in patients undergoing spinal surgeries.

Case Presentation We report a case of a 70-year-old male polytrauma patient presenting with a left first-rib fracture and an adjacent hematoma around the brachial plexus without preoperative deficits. Subsequent to a lumbar spinal fusion in the prone position, he developed a postoperative left upper extremity monoplegia. The postoperative magnetic resonance imaging revealed an enhanced asymmetric signal in the trunks and cords of the left brachial plexus. He progressively improved with rehabilitation, a year after the initial presentation, with a residual wrist drop.

Conclusions Pan brachial plexus monoplegia, following spine surgery, is rare and under-reported pathology. To minimize the occurrence of this rare morbidity, appropriate considerations in preoperative evaluation and counseling, patient positioning, intraoperative anesthetic, and electrophysiological monitoring should be performed. We emphasize an unreported risk factor in polytrauma patients, predisposing this rare injury that is associated with prone spinal surgery positioning, SEPs being an extremely sensitive test intraoperatively and highlight the importance of counseling patients and families to the possibility of this rare occurrence.

Meralgia Paresthetica

PURPOSE OF REVIEW

This review article summaries the epidemiology, etiology, clinical presentations, and latest treatment modalities of meralgia paresthetica, including the latest data about peripheral and spinal cord stimulation therapy. Meralgia paresthetica (MP) causes burning, stinging, or numbness in the anterolateral part of the thigh, usually due to compression of the lateral femoral cutaneous nerve (LFCN).

RECENT FINDINGS

There are emerging data regarding the benefit of interventional pain procedures, including steroid injection and radiofrequency ablation, and other interventions including spinal cord and peripheral nerve stimulation reserved for refractory cases. The strength of evidence for treatment choices in meralgia paraesthetica is weak. Some observational studies are comparing local injection of corticosteroid versus surgical interventions. However, more extensive studies are needed regarding the long-term benefit of peripheral and spinal cord stimulation therapy.

Postoperative spinal alignment comparison of lateral versus supine patient position L5-S1 anterior lumbar interbody fusion

PURPOSE

Over the past decade, alternative patient positions for the treatment of the anterior lumbar spine have been explored in an effort to maximize the benefits of direct anterior column access while minimizing the inefficiencies of single or multiple intraoperative patient repositionings. The lateral technique allows for access from L1 to L5 through a retroperitoneal, muscle-splitting, transpsoas approach with placement of a large intervertebral spacer than can reliably improve segmental lordosis, though its inability to be used at L5-S1 limits its overall adoption, as L5-S1 is one of the most common levels treated and where high levels of lordosis are optimal. Recent developments in instrumentation and techniques for lateral-position treatment of the L5-S1 level with a modified anterior lumbar interbody fusion (ALIF) approach have expanded the lateral position to L5-S1, though the positional effect on L5-S1 lordosis is heretofore unreported. The purpose of this study was to compare local and regional alignment differences between ALIFs performed with the patient in the lateral (L-ALIF) versus supine position (S-ALIF).

METHODS

Retrospective, multi-center data and radiographs were collected from 476 consecutive patients who underwent L5-S1 L-ALIF (n = 316) or S-ALIF (n = 160) for degenerative lumbar conditions. Patients treated at L4-5 and above with other single-position interbody fusion and posterior fixation techniques were included in the analysis. Baseline patient characteristics were similar between the groups, though L-ALIF patients were slightly older (58 vs. 54 years), with a greater preoperative mean L5-S1 disk height (7.8 vs. 5.8 mm), and with less preoperative slip (6.6 vs. 8.5 mm), respectively. 262 patients were treated with only L-ALIF or S-ALIF at L5-S1 while the remaining 214 patients were treated with either L-ALIF or S-ALIF at L5-S1 along with fusions at other thoracolumbar levels. Lumbar lordosis (LL), L5-S1 segmental lordosis, L5-S1 disk space height, and slip reduction in L5-S1 spondylolisthesis were measured on preoperative and postoperative lateral X-ray images. LL was only compared between single-level ALIFs, given the variability of other procedures performed at the levels above L5-S1.

RESULTS

Mean pre- to postoperative L5-S1 segmental lordosis improved 39% (6.6°) and 31% (4.9°) in the L-ALIF and S-ALIF groups, respectively (p = 0.063). Mean L5-S1 disk height increased by 6.5 mm (89%) in the L-ALIF and 6.4 mm (110%) in the S-ALIF cohorts, (p = 0.650). Spondylolisthesis, in those patients with a preoperative slip, average reduction in the L-ALIF group was 1.5 mm and 2.2 mm in the S-ALIF group (p = 0.175). In patients treated only at L5-S1 with ALIF, mean segmental alignment improved significantly more in the L-ALIF compared to the S-ALIF cohort (7.8 vs. 5.4°, p = 0.035), while lumbar lordosis increased 4.1° and 3.6° in the respective groups (p = 0.648).

CONCLUSION

Use of the lateral patient position for L5-S1 ALIF, compared to traditional supine L5-S1 ALIF, resulted in at least equivalent alignment and radiographic outcomes, with significantly greater improvement in segmental lordosis in patients treated only at L5-S1. These data, from the largest lateral ALIF dataset reported to date, suggest that-radiographically-the lateral patient position can be considered as an alternative to traditional ALIF positional techniques.

Brachial Plexus Injury and Musculocutaneous Nerve Palsy During Prone Positioning in a Patient With COVID-19

Prone positioning is crucial in the respiratory management of patients with acute respiratory distress syndrome (ARDS) and reduces mortality. However, this may be complicated by compression-related peripheral nerve injury. We report the case of a male in his 80s with obesity admitted to the intensive care unit (ICU) with COVID-19 pneumonia who developed brachial plexus disorder in the right upper extremity and musculocutaneous neuropathy in the left. The patient's cough, dyspnea, and fatigue did not improve; therefore, he was intubated and placed in the prone position for one week. The patient complained of bilateral upper limb weakness on regaining consciousness. We diagnosed left musculocutaneous nerve palsy and right brachial plexus palsy based on physical findings and needle electromyography (EMG). Physical therapy was initiated, including joint range-of-motion exercises focused on preventing contractures in the extremities and active assistive exercises. Motor impairment improved, and the patient was discharged from the rehabilitation center.

Resection of disseminated recurrent myxopapillary ependymoma with more than 4-year follow-up: operative nuance for prolonged prone position. Illustrative case

BACKGROUND

Symptomatic disseminated myxopapillary ependymoma (MPE) in a young person presents a daunting challenge because the risks of prolonged prone positioning and spinal cord injury may outweigh the likelihood of attaining the benefit of gross total resection.

OBSERVATIONS

The authors reported the case of a 15-year-old girl with five discrete recurrent spinal cord ependymomas. The patient received a 25-hour surgical procedure for gross total resection of the tumors and fusion over an approximately 33-hour period. She experienced complete resolution of all preoperative neurological symptoms and subsequently received adjuvant radiation therapy. At 52 months after surgery, she was still experiencing neurologically intact, progression-free survival. This case illustrated one of the most extensive recurrent tumor resections for MPE with prolonged disease-free survival reported to date. It may also represent the longest prone position spinal case reported and was notable for a lack of any of the complications commonly associated with the prolonged prone position.

LESSONS

The authors discussed the complexity of surgical decision-making in a symptomatic patient with multiple disseminated metastases, technical considerations for resection of intradural and intramedullary spinal cord tumors, and considerations for avoiding complications during prolonged positioning necessary for spinal surgery.

Biomechanical Evaluation of an Oblique Lateral Locking Plate System for Oblique Lumbar Interbody Fusion: A Finite Element Analysis

OBJECTIVE

The oblique lateral locking plate system (OLLPS) is a novel internal fixation with a locking and reverse pedicle track screw configuration designed for oblique lumbar interbody fusion (OLIF). The OLLPS is placed in a single position through the oblique lateral surgical corridor to reduce operative time and complications associated with prolonged anesthesia and prone positioning. The purpose of this study was to verify the biomechanical effect of the OLLPS.

METHODS

An intact finite element model of L1-S1 (intact) was established based on computed tomography images of a healthy male volunteer. The L4-L5 intervertebral space was selected as the surgical segment. The surgical models were established separately based on OLIF surgical procedures and different internal fixations: 1) stand-alone OLIF (SA); 2) OLIF with a 2-screw lateral plate; 3) OLIF with a 4-screw lateral plate; 4) OLIF with OLLPS; and 5) OLIF with bilateral pedicle screw fixation (BPS). After validation of the intact model, physiologic loads were applied to the superior surface of L1 to simulate motions such as flexion, extension, left bending, right bending, left rotation, and right rotation. The evaluation indices included the L4/5 range of motion, the L4 maximum displacement, and the maximum stresses of the superior and inferior end plates, the cage, and the supplemental fixation.

RESULTS

During OLIF surgery, the OLLPS provided multiplanar stability similar to that provided by BPS. Compared with 2-screw lateral plate and 4-screw lateral plate, OLLPS had better biomechanical properties in terms of enhancing the instant stability of the surgical segment, reducing the stress on the superior and inferior end plates of the surgical segment, and decreasing the risk of cage subsidence.

CONCLUSIONS

With a minimally invasive background, the OLLPS can be used as an alternative to BPS in OLIF and it has better prospects for clinical promotions and applications.

Rehabilitation of COVID-19 patients with respiratory failure and critical illness disease in Slovenia: an observational study

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection often causes pneumonia and respiratory failure that may lead to postintensive care syndrome, including critical illness neuropathy (CIN) and critical illness myopathy (CIM). The data on the rehabilitation outcomes of post-novel coronavirus disease (COVID) patients with CIN and CIM following respiratory failure and mechanical ventilation are still limited. To address this, we enrolled in our prospective observational study a sample of 50 consecutive COVID-19 patients admitted to our facility between 2 November 2020 and 3 May 2021 with electrophysiologically confirmed or clinically suspected diagnosis of CIN/CIM. The functional abilities were assessed at admission and discharge with the Functional Independence Measure (FIM), The Canadian Occupational Performance Measure, 10-metre walk test, 6-min walk test and the de Morton Mobility Index. The gain in motor FIM and the length of stay were used as an index of rehabilitation efficiency. Nutritional status was also assessed using anthropometric measurements and bioelectrical Impedance analysis. Psychologic evaluation was performed at admission only. At admission, functional limitations and severe malnutrition were present in all patients with psychologic problems in about one third. At discharge (42 ± 16 days later), clinically important and statistically significant improvements were found in all outcome measures, which was also noted by the patients. The gain in motor FIM was larger with the longer length of stay up to 2 months and plateaued thereafter. We conclude that post-COVID-19 patients who develop CIN/CIM following respiratory failure can improve functional and nutritional status during inpatient rehabilitation.

Surgical fixation of pathologic and traumatic spinal fractures using single position surgery technique in lateral decubitus position

STUDY DESIGN

Retrospective Case Series.

OBJECTIVES

This study aims to determine complications, readmission, and revision surgery rates in patients undergoing single position surgery (SPS) for surgical treatment of traumatic and pathologic thoracolumbar fractures.

METHODS

A multi-center review of patients who underwent SPS in the lateral decubitus position (LSPS) for surgical management of traumatic or pathologic thoracolumbar fractures between January 2016 and May 2020 was conducted. Operative time, estimated blood loss (EBL), intraoperative complications, postoperative complications, readmissions, and revision surgeries were collected.

RESULTS

A total of 12 patients with a mean age of 45 years (66.67% male) were included. The majority of patients underwent operative treatment for acute thoracolumbar trauma (66.67%) with a mean injury severity score (ISS) of 16.71. Mean operative time was 175.5 min, mean EBL of 816.67 cc. Five patients experienced a complication, two of which required revision surgery for additional decompression during the initial admission. All ambulatory patients were mobilized on postoperative day 1. The mean hospital length of stay (LOS) was 9.67 days.

CONCLUSION

The results of this case series supports LSPS as a feasible alternative to the traditional combined anterior-posterior approach for surgical treatment of pathologic and thoracolumbar fractures. These results are similar to reductions in operative time, EBL, and LOS seen in the elective spine literature with LSPS.

LEVEL OF EVIDENCE

IV.

The Oral Complications of COVID-19

Background: COVID-19 is a novel coronavirus infectious disease associated with the severe acute respiratory syndrome. More and more patients are being cured due to the development of clinical guidelines for COVID-19 pneumonia diagnosis, treatment, and vaccines. However, the long-term impact of COVID-19 on patients after recovery is unclear. Currently available reports have shown that patients recovered from COVID-19 continue to experience health problems in respiratory and other organ systems. Oral problem is one of the important complications which has serious impacts on the rehabilitation and future quality of life, such as ageusia and macroglossia, but the oral complication is often being neglected.

Aim of Review: From the perspective of stomatology, we summarized and elaborated in detail the types, pathogenesis of oral complications from COVID-19 patients after rehabilitation, and the reported prevention or treatment recommendations which may improve the COVID-19 patients associated oral diseases.

Key Scientific Concepts of Review: 1) To understand the common oral complications and the mechanisms of the development of oral complications after the COVID-19 recovery; 2) To summary the practical strategies to prevent the oral complications and construct the rehabilitation plans for patients with oral complications.

Patient-Customised Theatre Mattress Supports for Spinal Surgery: A Pilot Study Presenting a Novel Engineering Virtual Design and Manufacturing Technique

Optimal patient positioning for spine surgery is vital for surgical success and the minimisation of complications intra-/post-operatively. In patients with complex co-morbidities, commercially available surgical positioning equipment is inadequate. To overcome this, a novel method was developed to create custom-fit patient-specific theatre mattresses for patients undergoing spine surgery. An innovative digital workflow involving 3D surface scanning, 3D simulation and computer aided design was developed to manufacture customised theatre supports with patient-specific requirements. These supports offered the surgeon an enhanced ability to relieve load bearing on prominent anatomical features or where desired, to tailor the support surface to the patient's anatomy for lengthy surgery. The bespoke theatre mattress was evaluated by whether the support resulted in a complication-free surgery. Using this new workflow, case examples for two patients with complex co-morbidities were described. The spine surgeon and anaesthetist reported the patient-specific custom mattresses were fit as per the required design, provided sufficient clearance around anatomical prominences and areas that required to be unloaded, had sufficient clearance for the anaesthetic method and cannulation, provided excellent surgical access and stability during surgery, and postoperatively no soft tissue overload over bony prominence and implanted devices. Positive patient outcomes after successful lengthy surgical interventions were associated with these patient-specific, contoured mattress supports. Future projects will seek to utilise this technology for other types of surgeries and intra-operative positioning requirements, and for a broader demographic of patients in both the paediatric and adult setting.

Prone position plexopathy: an avoidable complication of prone positioning for COVID-19 pneumonitis?

Prone positioning is a mainstay of management for those presenting to the intensive care unit with moderate-to-severe acute respiratory distress syndrome due to COVID-19. While this is a necessary and life-saving intervention in selected patients, careful positioning and meticulous care are required to prevent compression and traction of the brachial plexus, and resultant brachial plexopathy. We describe two patients who developed a brachial plexus injury while undergoing prone positioning for management of COVID-19 pneumonitis. Both patients were diabetic and underwent prolonged periods in the prone position during which the plexopathy affected arm was abducted for 19 and 55 hours, respectively. We discuss strategies to reduce the risk of this rare but potentially disabling complication of prone positioning.

Massive macroglossia, a rare side effect of COVID-19: clinical, histologic, and genomic findings in COVID-19-positive versus COVID-19-negative patients

Purpose

The primary purpose of this study is to identify if there is an underlying genetic predisposition for COVID-related macroglossia and if this susceptibility is higher among individuals of African heritage. Secondary objectives include determining if genetic testing of COVID-infected patients who are intubated and prone could identify patients with higher susceptibility to the development of macroglossia.

Methods

A retrospective chart review was completed for each patient, and prospectively, genetic and histopathologic analyses were completed. Whole-exome sequencing was completed on two patients; immunohistochemistry was completed on the COVID-positive tissue samples.

Results

Histopathology of the COVID-positive patient revealed significant peri-lymphocytic infiltrate, which was absent in the COVID-negative patient. Immunohistochemistry confirmed the presence of immune cells. Results from the whole-exome sequencing were inconclusive.

Conclusion

The findings of this study are consistent with others that have observed a lymphocytic infiltrate in the organs of patients infected with SARS-CoV-2. On histology, IHC highlighted a CD45 + predominance, indicating that a robust immune response is present in the tissues. The pathobiology of this phenomenon and its role in the development and/or persistence of massive macroglossia requires further study.

[Potential complications of patient positioning in spine surgery]

Patient position on the operating table during spine surgery is important for optimal intraoperative manipulations. However, this position is far from physiological one. An unnatural position, surgery time and sometimes necessary intraoperative change in body position can lead to certain neurological and somatic complications. Most of these events can significantly reduce the patient's working capacity and quality of life and even result disability. Medical staff placing the patient on operating table, neurosurgeons and anesthesiologists should be aware of risk factors of similar complications and their prevention. The authors describe the most serious and difficult for correction conditions, such as peripheral neuropathy, damage to visual analyzer, as well as optimal method of patient positioning.

Surgical Residents at the Forefront of the COVID-19 Pandemic: Perspectives on Redeployment

The COVID-19 pandemic has led many of us to re-evaluate our approaches to disaster management, reflect on our experiences, and be reminded of the strong resolve for our work. This article details a resident's perspective on redeployment of surgical residents to the COVID-19 frontline setting, using the example of the COVID-19 intensive care unit. Redeployment during a pandemic brings the unique opportunity to collaborate with colleagues on the frontlines and learn alongside one another about the evolving management of this disease. During this ongoing pandemic, it is incumbent upon us as clinicians to work together in a multidisciplinary manner and reflect on ways this pandemic impacts the delivery of patient care.

Perioperative Care of Patients Undergoing Major Complex Spinal Instrumentation Surgery: Clinical Practice Guidelines From the Society for Neuroscience in Anesthesiology and Critical Care

Evidence-based standardization of the perioperative management of patients undergoing complex spine surgery can improve outcomes such as enhanced patient satisfaction, reduced intensive care and hospital length of stay, and reduced costs. The Society for Neuroscience in Anesthesiology and Critical Care (SNACC) tasked an expert group to review existing evidence and generate recommendations for the perioperative management of patients undergoing complex spine surgery, defined as surgery on 2 or more thoracic and/or lumbar spine levels. Institutional clinical management protocols can be constructed based on the elements included in these clinical practice guidelines, and the evidence presented.

Prone position pressure sores in the COVID-19 pandemic: The Madrid experience

BACKGROUND

In the context of the COVID-19 pandemic, prone position (PP) has been frequently used in the intensive care units to improve the prognosis in patients with respiratory distress. However, turning patients to prone imply important complications such as pressure ulcers. The aim of this paper is to describe the prevalence and characteristics of prone-positioning pressure sores (PPPS) and analyze the related risk factors.

METHODS

A case-control study was performed in Gregorio Maranon hospital in Madrid during the COVID-19 pandemic between April and May 2020. We enrolled 74 confirmed COVID-19 patients in critical care units with invasive mechanical ventilation who were treated with pronation therapy. There were 57 cases and 17 controls. Demographic data, pronation maneuver characteristics and PPPS features were analyzed.

RESULTS

In the case group, a total number of 136 PPPS were recorded. The face was the most affected region (69%). Regarding the severity, stage II was the most frequent. The main variables associated with an increased risk of PPPS were the total number of days under pronation cycles, and PP maintained for more than 24 h. The prealbumin level at admission was significantly lower in the case group. All of the ulcers were treated with dressings. The most frequent acute complication was bleeding (5%).

CONCLUSIONS

According to our study, PPPS are related to the characteristics of the maneuver and the previous nutritional state. The implementation of improved positioning protocols may enhance results in critical patient caring, to avoid the scars and social stigma that these injuries entail.

Macroglossia secondary to prolonged prone positioning for management of COVID-19 respiratory failure

We report the case of a 59-year-old woman who developed acute macroglossia following prolonged prone positioning for management of COVID-19. We found that Biotene mixed in glycerin was effective at removing keratinised lingual plaques and better tolerated than Biotene alone. Additionally, uniform tongue compression applied via tubular elastic dressing yielded more efficacious results than uneven tongue compression via Coban.

An innovative adjustable prone positioning frame for treatment of severe kyphosis secondary to ankylosing spondylitis with two-level osteotomy

PURPOSE

This study aims to introduce an innovative adjustable prone positioning frame (APPF) and explore its feasibility and safety for treatment of severe kyphosis secondary to ankylosing spondylitis (AS) with two-level osteotomy.

METHODS

A retrospective, non-controlled study was conducted to illustrate the process where 13 patients diagnosed with severe kyphosis secondary to AS received operations on the APPF. Parameters of chin brow vertical angle (CBVA), global kyphosis (GK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL) and sagittal vertical axis (SVA) were measured. Positioning time, operation time, intraoperative blood loss aḥd complications were also determined. The Scoliosis Research Society outcomes instrument (SRS-22) was applied for clinical assessment.

RESULTS

All patients were placed on the APPF successfully with the positioning time of 2.92 ± 0.76 min, received operation with 457.00 ± 88.04 min and had blood loss of 2330.77 ± 1423.25 ml. Four cases experienced pain due to tensional skin of the abdomen and one case suffered cerebrospinal fluid leakage postoperatively, but these patients were all cured conservatively. No neurological complications were observed, although sagittal translation occurred in four patients. Significant improvements were detected in CBVA, GK, TLK, LL and SVA postoperatively (P < 0.05), but no significant difference was observed between postoperation and the final follow-up (P > 0.05). The SRS-22 scores at 2 years after operation were significantly higher than those before operation (P < 0.05).

CONCLUSION

The innovative APPF provided great convenience to place patients with severe kyphosis secondary to AS in a prone position. Performing two-level osteotomy with the aid of APPF is safe, feasible and effective.

Risk Factors for Facial Pressure Ulcers in Patients Who Underwent Prolonged Prone Orthopedic Spine Surgery

MINI

This study evaluated incidence and risk factors associated with the development of facial pressure ulcers (FPU) in patients who underwent spine surgery in prone position. A total of 300 cases were studied. The incidence of FPU after prone spine surgery using head padded device >3 hours was 27.3%. Hypotension, higher temperature, prolonged operation time, and much crystalloid therapy were the independent risk factors.

Applied anatomy and surgical technique of the lateral single-position L5-S1 fusion

The latest development in the anterior lumbar interbody fusion (ALIF) procedure is its application in the lateral position to allow for simultaneous posterior percutaneous screw placement. The technical details of the lateral ALIF technique have not yet been described. To describe the surgical anatomy relevant to the lateral ALIF approach we performed a comprehensive anatomical study. In addition, the preoperative imaging, patient positioning, planning of the skin incision, positioning of the C-arm, surgical approach, and surgical technique are discussed in detail. The technique described led to the successful use of the lateral ALIF technique in our clinical cases. No lateral ALIF procedure needed to be aborted during these cases. Our present work gives detailed anatomical background and technical details for the lateral ALIF approach. This teaching article can provide readers with sufficient technical and anatomical knowledge to assist them in performing their first lateral ALIF procedure.