Longer Operative Time in Elderly Patients Undergoing Posterior Lumbar Fusion Is Independently Associated With Increased Complication Rate

Identification of an Operative Time Threshold for Substantially Increased Postoperative Complications Among Elderly Spine Surgery Patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To identify whether thresholds exist beyond which operative duration or age increases risks for complications among patients ≥65 years undergoing elective spine surgery.

METHODS

Elective inpatient spine procedures unrelated to infection/trauma/tumor diagnoses in patients <65 years recorded in the 2006-2019 American College of Surgeons National Surgical Quality Improvement database were identified. Univariate analyses was used to compare 30 day complication rates among 5 operative duration and age-stratified groups. To quantify the risk of prolonged operative duration on complications, multivariate analyses were performed controlling for confounders. A generalized linear model was used to assess the individual and combined effect strength of age and operative duration on complication rates.

RESULTS

Among 87,705 patients stratified by operative duration, 30 day complication rates rose nonlinearly as operative duration increased, with a sharp rise after 4.0-4.9 hours (28.3% at 4.0-4.9 hours, 51.7% at ≥5 hours, P < .001). Multivariate analysis found operative duration was independently associated with increased risk of overall complications (odds ratio 1.10→1.69, P < .001) and medical complications (odds ratio 1.19→1.98, P < .001). Although complication rates rose by age (all P < .001), age was not independently predictive of overall complications within any operative duration group on multivariate analysis. Operative duration had a greater effect (η2P = .067) than age (η2P = .003) on overall complication rates.

CONCLUSIONS

Increased operative duration was strongly associated with 30 day complication rates, particularly beyond a threshold of 5 hours. Furthermore, operative duration had a notably larger effect on overall complication rates than age.

Lumbar Decompression versus Decompression and Fusion in Octogenarians: Complications and Clinical Course With 3-Year Follow-Up

STUDY DESIGN

Retrospective review.

OBJECTIVES

This study aimed to assess and compare the clinical course and complications between surgical decompression and decompression with fusion in lumbar spine patients aged ≥80 years.

METHODS

A retrospective review of electronic medical records at a single institution was conducted between September 2005 and December 2021. Logistic regression was used to identify potential risk factors for the occurrence of complications.

RESULTS

Over a 16-year period, 327 patients were allocated to the decompression only group and 89 patients were allocated to the decompression and instrumented fusion group. The study had a mean follow-up duration of 36.7 ± 12.4 months. When assessing the CCI, patients of the instrumentation group had fewer comorbidities (8.9 ± .5 points vs 6.2 ± 1.5 points; P < .001), significantly longer surgical duration (290 ± 106 minutes vs 145 ±50.2 minutes; P < .001), significantly higher volume of intraoperative blood loss (791 ± 319.3 ml vs 336.1 ± 150.8 ml; P < .001), more frequent intraoperative blood transfusion (7 ± 2.1% vs 16± 18.0%; P < .001), and extended stays in the intensive care unit and hospitalization rates. Logistic regression analysis revealed that surgical duration and extent of surgery were unique risk factors for the occurrence of complications.

CONCLUSIONS

Lumbar decompression and additional fusion in octogenarians are considerable treatment techniques; albeit associated with increased complication risks. Prolonged operative time and extent of surgery are critical confounding factors associated with higher rates of postoperative complications. Surgery should only be performed after careful outweighing of potential benefits and risks.

Posterior Instrumented Spinal Surgery Outcomes in the Elderly: A Comparison of the 5-Item and 11-Item Modified Frailty Indices

STUDY DESIGN

Retrospective Cohort.

OBJECTIVES

To validate the most concise risk stratification system to date, the 5-item modified frailty index (mFI-5), and compare its effectiveness with the established 11-item modified frailty index (mFI-11) in the elderly population undergoing posterior instrumented spine surgery.

METHODS

A single centre retrospective review of posterior instrumented spine surgeries in patients aged 65 years and older was conducted. The primary outcome was rate of post-operative major complications (Clavien-Dindo Classification ≥ 4). Secondary outcome measures included rate of all complications, 6-month mortality and surgical site infection. Multi-variate analysis was performed and adjusted receiver operating characteristic curves were generated and compared by DeLong's test. The indices were correlated with Spearman's rho.

RESULTS

272 cases were identified. The risk of major complications was independently associated with both the mFI-5 (OR 1.89, 95% CI 1.01-3.55, P = .047) and mFI-11 (OR 3.73, 95% CI 1.90-7.30, P = .000). Both the mFI-5 and mFI-11 were statistically significant predictors of risk of all complications (P = .007 and P = .003), surgical site infection (P = .011 and P = .003) and 6-month mortality (P = .031 and P = .000). Adjusted ROC curves determined statistically similar c-statistics for major complications (.68 vs .68, P = .64), all complications (.66 vs .64, P = .10), surgical site infection (.75 vs .75, P = .76) and 6-month mortality (.83 vs .81, P = .21). The 2 indices correlated very well with a Spearman's rho of .944.

CONCLUSIONS

The mFI-5 and mFI-11 are equally effective predictors of postoperative morbidity and mortality in this population. The brevity of the mFI-5 is advantageous in facilitating its daily clinical use.

Advancing Prone-Transpsoas Spine Surgery: A Narrative Review and Evolution of Indications with Representative Cases

The Prone Transpsoas (PTP) approach to lumbar spine surgery, emerging as an evolution of lateral lumbar interbody fusion (LLIF), offers significant advantages over traditional methods. PTP has demonstrated increased lumbar lordosis gains compared to LLIF, owing to the natural increase in lordosis afforded by prone positioning. Additionally, the prone position offers anatomical advantages, with shifts in the psoas muscle and lumbar plexus, reducing the likelihood of postoperative femoral plexopathy and moving critical peritoneal contents away from the approach. Furthermore, operative efficiency is a notable benefit of PTP. By eliminating the need for intraoperative position changes, PTP reduces surgical time, which in turn decreases the risk of complications and operative costs. Finally, its versatility extends to various lumbar pathologies, including degeneration, adjacent segment disease, and deformities. The growing body of evidence indicates that PTP is at least as safe as traditional approaches, with a potentially better complication profile. In this narrative review, we review the historical evolution of lateral interbody fusion, culminating in the prone transpsoas approach. We also describe several adjuncts of PTP, including robotics and radiation-reduction methods. Finally, we illustrate the versatility of PTP and its uses, ranging from 'simple' degenerative cases to complex deformity surgeries.

An Analysis of a Decade of Lumbar Interbody Cage Failures in the United States: A MAUDE Database Study

STUDY DESIGN

A retrospective case series.

OBJECTIVE

This study aims to assess the rates of lumbar interbody cage failures based on their material and manufacturer.

SUMMARY OF BACKGROUND DATA

Perioperative lumbar interbody cage malfunctions are underreported events in the spine literature and may result in complications. Although the Food and Drug Administration ensures the safety of these devices under physiological conditions after implantation, these devices may experience nonphysiological conditions during implantation, which may be overlooked.

MATERIALS AND METHODS

The MAUDE database was examined for reports of lumbar cage device malfunctions from 2012 to 2021. Each report was categorized based on failure type and implant design. A market analysis was performed by dividing the total number of failures per year for each manufacturer by their approximate yearly revenue from spinal implants in the United States. Outlier analysis was performed to generate a threshold value above which failure rates were defined as greater than the normal index.

RESULTS

Overall, 1875 lumbar cage malfunctions were identified. Of these, 1230 (65.6%) were cage breakages, 257 (13.7%) were instrument malfunctions, 177 (9.4%) were cage migrations, 143 (7.6%) were assembly failures, 70 (4.5%) were screw-related failures, and 21 (1.1%) were cage collapses. Of the breakages, 923 (74.9%) occurred during insertion or impaction and 97 entries detailed a medical complication or a retained foreign body. Of the migrations, 155 (88.6%) were identified postoperatively, of which 73 (47.1%) detailed complications and 52 (33.5%) required a revision procedure. Market analysis demonstrated that Medtronic, Zimmer Biomet, Stryker, Seaspine, and K2M exceeded the calculated threshold.

CONCLUSIONS

Lumbar cages with polyether ether ketone core material failed more frequently by breakage, whereas titanium surface cages failed more frequently by migration. Failure rates varied depending on the manufacturer. Most cage breakages identified in the present study occurred intraoperatively during implantation. These findings call for a more detailed Food and Drug Administration evaluation of these intraoperative malfunctions before commercial approval.

LEVEL OF EVIDENCE

Level 4.

Percutaneous Computed Tomography-Guided Oxygen-Ozone (O2O3) Injection Therapy in Patients with Lower Back Pain-An Interventional Two-Year Follow-Up Study of 321 Patients

OBJECTIVES

To assess the effect of oxygen-ozone therapy guided by percutaneous Computed Tomography (CT) compared to corticosteroids in individuals experiencing lower back pain (LBP) not attributed to underlying bone-related issues.

METHODS

A total of 321 patients (192 males and 129 females, mean age: 51.5 ± 15.1 years) with LBP were assigned to three treatment groups: group A) oxygen-ozone only, group B) corticosteroids only, group C) oxygen-ozone and corticosteroids. Treatment was administered via CT-guided injections to the intervertebral disc (i.e., intradiscal location). Clinical improvement of pain and functionality was assessed via self-reported pain scales and magnetic resonance (MR) and CT imaging.

RESULTS

At all follow-up times, the mean score of the numeric rating scale and the total global pain scale (GPS) of study groups receiving oxygen-ozone (groups A and C) were statistically significantly lower than the study group receiving corticosteroids only (group B), with p < 0.001. There was a statistically significant difference between groups A and C at 30 days for the numeric rating scale.

CONCLUSIONS

The percutaneous application of oxygen-ozone in patients with LBP due to degeneration of the lumbosacral spine showed long-lasting significant pain reduction of up to two years post-treatment when compared to corticosteroids alone. Combination therapy of oxygen-ozone and corticosteroids can be useful as corticosteroids showed statistically significant improvement in LBP earlier than the oxygen-ozone-only treatment.

Simultaneous Single-Position Lateral Lumbar Interbody Fusion Surgery and Unilateral Percutaneous Pedicle Screw Fixation for Spondylolisthesis

OBJECTIVE

To evaluate the clinical and radiological efficacy of a combine of lateral single screw-rod and unilateral percutaneous pedicle screw fixation (LSUP) for lateral lumbar interbody fusion (LLIF) in the treatment of spondylolisthesis.

METHODS

Sixty-two consecutive patients with lumbar spondylolisthesis who underwent minimally invasive (MIS)-TLIF with bilateral pedicle screw (BPS) or LLIF-LSUP were retrospectively studied. Segmental lordosis angle (SLA), lumbar lordosis angle (LLA), disc height (DH), slipping percentage, the cross-sectional areas (CSA) of the thecal sac, screw placement accuracy, fusion rate and foraminal height (FH) were used to evaluate radiographic changes postoperatively. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the clinical efficacy.

RESULTS

Patients who underwent LLIF-LSUP showed shorter operating time, less length of hospital stay and lower blood loss than MIS-TLIF. No statistical difference was found between the 2 groups in screw placement accuracy, overall complications, VAS, and ODI. Compared with MIS-TLIF-BPS, LLIF-LSUP had a significant improvement in sagittal parameters including DH, FH, LLA, and SLA. The CSA of MIS-TLIF-BPS was significantly increased than that of LLIF-LSUP. The fusion rate of LLIF-LSUP was significantly higher than that of MIS-TLIF-BPS at the follow-up of 3 months postoperatively, but there was no statistical difference between the 2 groups at the follow-up of 6 months, 9 months, and 12 months.

CONCLUSION

The overall clinical outcomes and complications of LLIF-LSUP were comparable to that of MIS-TLIF-BPS in this series. Compared with MIS-TLIF-BPS, LLIF-LSUP for lumbar spondylolisthesis represents a significantly shorter operating time, hospital stay and lower blood loss, and demonstrates better radiological outcomes to maintain lumbar lordosis, and reveal an overwhelming superiority in the early fusion rate.

Minimally invasive lateral single-position surgery for multilevel degenerative lumbar spine disease: feasibility and perioperative results in a single Latin-American spine center

INTRODUCTION

Within advances in minimally invasive spine surgery, the implementation of lateral single position (LSP) increases efficiency while limiting complications, avoiding intraoperative repositioning and diminishing surgical time. Most literature describes one-level instrumentation of the lumbar spine; this study includes the use of LSP for multilevel degenerative disease.

OBJECTIVE

The objective of the article is to analyze initial clinical results and complications in the use of LSP for multiple level instrumentation in adults with lumbar degenerative disease.

METHODS

A retrospective early clinical series was performed for patients who had multiple level instrumentation in LSP between August 2019 and September 2022 at the Hospital Universitario San Ignacio in Bogota, Colombia. Inclusion criteria were patients older than 18 years with symptomatic lumbar degenerative disease, undergoing any combination of multilevel anterior lumbar interbody fusion, lateral lumbar interbody fusion (LLIF) and pedicle screw fixation.

RESULTS

Forty patients with an average age of 61.3 years were included, with diagnosis of multilevel degenerative spondylotic changes. Four-, three- and two-level interventions were performed in 52.5, 35 and 12.5%, respectively. Average time per level was 68.9 min, and length of hospital stay had an average of 2.4 days, with all patients starting ambulation within the first postoperative day.

CONCLUSION

Procedural time and blood loss were similar to those reported in literature. No severe lesions, postoperative infections or reinterventions took place. Although it was a small number of patients and further clinical trials are needed, LSP for multiple levels is apparently safe with adequate outcomes which may improve efficiency in the operating room.

Chief Residents Can Safely Operate on Older and Frail Patients

INTRODUCTION

Older age and frailty increase the risk of poor recovery after surgery. We hypothesized that general surgery operations performed by supervised chief residents, as opposed to attending physicians, would still be safe for these vulnerable patients.

MATERIALS AND METHODS

We used the Veterans Affairs Surgical Quality Improvement Program database to identify 114,525 patients age 65+ y, including 18,030 patients age 80+ y and 47,555 categorized as frail, who had a general surgery procedure from 1999 to 2019 that was performed by an attending physician or by a supervised chief resident. Frailty was defined by a Risk Analysis Index score ≥30. We used inverse probability weighting on the propensity score to compare morbidity and mortality between operations performed by attendings versus chief residents.

RESULTS

Patients 65 y and above had a 2.1% increase in postoperative complications when the surgery was performed by a chief resident instead of an attending surgeon (95%CI 1.2%-3.0%, P < 0.0001). A similarly increased risk of complications was seen for patients age ≥80 y old (+2.3%, 95%CI 0.7%-3.9%, P = 0.004) and for frail patients (+2.7%, 95%CI 1.4%-4.0%, P < 0.0001). There were no differences in mortality for patients age 65+ y (+0.2%, 95%CI -0.1%-0.5%, P = 0.2), 80+ y (+0.3%, 95%CI -0.6%-1.1%, P = 0.5), or frail patients (+0.2%, 95%CI -0.5%-0.8%, P = 0.6) when their operations were performed by chief residents.

CONCLUSIONS

We found a small increase in morbidity and no difference in mortality when older or frail patients were operated on by chief residents rather than attending surgeons. Our findings suggest that it is reasonable and safe for training programs to allow appropriately supervised chief residents to operate on older or frail patients.

Comparison of Perioperative Outcomes in Patients Undergoing Short-Level Lumbar Fusion Surgery After Implementing Enhanced Recovery After Surgery: A Propensity Score Matching Analysis Focusing on Young-Old and Old-Old

Background

There were exponentially increased studies focused on revealing the satisfactory outcomes after implementing enhanced recovery after surgery (ERAS) in patients undergoing lumbar fusion surgery. However, little attention has been paid to the impact of chronologic age alone on perioperative outcomes.

Methods

In the present study, patients were dichotomized into two groups: young-old (65-79 years), and old-old (80 years and older). Given the heterogeneity and age-related comorbidities in this population and the need to compare similar groups, we performed propensity score matching for gender, body mass index (BMI), operation time, American Society of Anesthesiologists (ASA) grade, Charlson Comorbidity Index (CCI), fusion levels and frail status. Perioperative outcomes were compared between two groups.

Results

In our study, we found there were significant discrepancies in length of stay (LOS) (7.17 ± 2.81 vs 8.11 ± 3.57 days, p = 0.031) and postoperative nausea and vomiting (3.7% vs 11.0%, p = 0.038); however, there were no significant differences in C-reactive protein (21.50 ± 26.52 vs 19.22 ± 22.04 mg/L, p = 0.490), overall complication rates (24.8% vs 33.0%, p = 0.179), ambulation time (2.89 ± 1.34 vs 2.55 ± 1.49 days, p = 0.078) or removal of urinary catheter time (2.47 ± 1.44 vs 2.32 ± 1.40 days, p = 0.446).

Conclusion

There were few differences in perioperative outcomes between young-old and old-old groups. Despite similar postoperative complication rates, the old-old group might experience longer LOS when complications occur. More importantly, current outcomes suggested that chronologic age alone does not appear to have the capacity to reflect the tolerance of elderly patients to surgery.

Freehand Pre-drilling Technique for Lateral Mass Screw Fixation Is More Efficient and Reliable Versus Sequential Drilling Technique: A Sawbone Analysis

Background Since posterior cervical fixation with lateral mass screws was introduced in 1979, multiple techniques have been described in the literature. However, no study to date has determined whether pre-drilling all lateral masses prior to screw insertion has a benefit over the traditional sequential drilling and screw insertion on the alignment of the screw-rod construct. This study sought to determine the efficacy and efficiency in achieving alignment with a novel pre-drilling technique compared to the traditional sequential drilling technique. The authors hypothesized that the novel pre-drilling technique could be applied more quickly and precisely than the traditional sequential drilling technique. Methods Eight cervical spine sawbones models were utilized to place 64 lateral mass screws by two surgeons. The pre-drilling technique was utilized to place 32 screws in four models, and the sequential drilling technique was utilized to place the 32 screws in the remaining four models. In the traditional sequential drilling technique, each lateral mass underwent screw tract preparation and insertion before proceeding to the subsequent vertebra. In the pre-drilling technique, all lateral masses were marked and drilled sequentially before screw placement. CT imaging with 3D reconstructions was generated for all models. Variability in screw placement and time taken to fully instrument the models were compared.  Results The mean time to completion of the pre-drilling technique was 337 ± 22 seconds compared to 490 ± 22 seconds with the traditional technique (p<0.01). There was a significantly higher variability in the coronal plane within the traditional group between C5 and C6 compared to other adjacent vertebrae (p<0.05). There was no significant difference in the start point variability and the overall tightness of line fit between the techniques. Conclusions Our study suggests that a novel pre-drilling technique for lateral mass screw insertion may be more efficient and reliable than the traditional sequential drilling technique. In addition, this technique may reduce the need for rod contouring or additional implants to optimize the alignment of cervical instrumentation. However, further clinical studies are necessary to validate the potential clinical and radiologic benefits of this described technique.

Cefazolin prophylaxis in spine surgery: patients are frequently underdosed and at increased risk for infection

BACKGROUND CONTEXT

Perioperative antibiotics are critical in reducing the risk of postoperative spine infections. However, the efficacy and optimal weight-based prophylactic cefazolin dosing is unclear.

PURPOSE

To determine (1) if inadequate weight-based prophylactic dosing of cefazolin affects infection rates after spinal fusions, and (2) identify the optimal dosing of cefazolin.

STUDY DESIGN/SETTING

Single center retrospective cohort PATIENT SAMPLE: Patients undergoing posterior cervical or lumbar spinal fusion between January 2000 and October 2020 OUTCOME MEASURES: Postoperative surgical site infection status METHODS: Patients were grouped based on our institutionally derived dosing adequacy standards, 1 g for <60 kg, 2 g for 60 to 120 kg, and 3 g for >120 kg. Univariate comparisons and multivariate regressions identified the effect of inadequate dosing on infection rate. Patients were subsequently regrouped into cefazolin dose (grams) administered and logistic regression and receiver operating characteristic curves were compiled to determine the probability of infection based on cefazolin dose and patient weight. Alpha was set at 0.05.

RESULTS

A total of 2,643 patients met inclusion criteria and 95 infections (3.6%) were identified. The infection rate was higher in the inadequate dosing group (5.86% vs. 2.58%, p<.001). Adequate dosing was a predictor of decreased infections after lumbar fusion (OR: 0.43, p<.001), but not posterior cervical fusions (OR: 0.47, p=.065). Patients were subsequently regrouped into 1 g or 2 g of cefazolin administered resulting in a 5.01% and 2.77% infection rate, respectively (p=.005). The area under the curve (AUC) and 95% confidence interval for one (0.850 [0.777-0.924]) and two (0.575 [0.493-0.657]) g of cefazolin demonstrated lower infection rates for patients given 2 g cefazolin.

CONCLUSIONS

Patients receiving an inadequate weight-based dose of preoperative cefazolin had an increased risk of infection following spinal fusion surgery. Two grams prophylactic cefazolin significantly reduces the likelihood of infection.

Postoperative Opioid Use Following Single-Level Transforaminal Lumbar Interbody Fusion Compared with Posterolateral Lumbar Fusion

OBJECTIVE

To compare postoperative opioid morphine milligram equivalents (MME) prescriptions for opioid-naïve patients undergoing single-level transforaminal lumbar interbody fusion (TLIF) versus posterolateral lumbar fusion (PLF) and total postoperative MME prescribed based on operative duration.

METHODS

Patients undergoing single-level TLIF or PLF from September 2017 to June 2020 were identified from a single institution. Patients were first grouped based on procedure type (TLIF or PLF) and subsequently regrouped based on median operative duration. Statistical tests compared patient demographics and opioid prescription data between groups. Multivariate regressions were performed to control for demographics, operative time, and procedure type.

RESULTS

Of 345 patients undergoing single-level PLF or TLIF, 174 (50.4%) were opioid-naïve; 101 opioid-naïve patients (58.0%) underwent PLF and 73 (42.0%) underwent TLIF. Patients undergoing TLIF received more opioid prescriptions (1.99 vs. 1.26, P < 0.001) and total MME (91.2 vs. 66.8, P = 0.002). After regrouping patients based on operative duration, independent of procedure type, there were no differences in postoperative opioid prescriptions, and Spearman rank correlation coefficient between total MME and operative duration was r = 0.014. Multivariate analysis identified TLIF as an independent predictor of increased postoperative opioid prescriptions (β = 0.64, P < 0.001), prescribers (β = 0.49, P = 0.003), and MME (β = 24.4, P = 0.030).

CONCLUSIONS

Opioid-naïve patients undergoing single-level TLIF receive a greater number of postoperative opioids than patients undergoing single-level PLF, and TLIF was an independent predictor of increased postoperative opioid prescribers, prescribers, and MME. There were no differences in postoperative opioid prescriptions when assessing patients based on operative duration.

Single-position circumferential lumbar spinal fusion: an overview of terminology, concepts, rationale and the current evidence base

PURPOSE

To provide definitions and a conceptual framework for single position surgery (SPS) applied to circumferential fusion of the lumbar spine.

METHODS

Narrative literature review and experts' opinion.

RESULTS

Two major limitations of lateral lumbar interbody fusion (LLIF) have been (a) a perceived need to reposition the patient to the prone position for posterior fixation, and (b) the lack of a robust solution for fusion at the L5/S1 level. Recently, two strategies for performing single-position circumferential lumbar spinal fusion have been described. The combination of anterior lumbar interbody fusion (ALIF) in the lateral decubitus position (LALIF), LLIF and percutaneous pedicle screw fixation (pPSF) in the lateral decubitus position is known as lateral single-position surgery (LSPS). Prone LLIF (PLLIF) involves transpsoas LLIF done in the prone position that is more familiar for surgeons to then implant pedicle screw fixation. This can be referred to as prone single-position surgery (PSPS). In this review, we describe the evolution of and rationale for single-position spinal surgery. Pertinent studies validating LSPS and PSPS are reviewed and future questions regarding the future of these techniques are posed. Lastly, we present an algorithm for single-position surgery that describes the utility of LALIF, LLIF and PLLIF in the treatment of patients requiring AP lumbar fusions.

CONCLUSIONS

Single position surgery in circumferential fusion of the lumbar spine includes posterior fixation in association with any of the following: lateral position LLIF, prone position LLIF, lateral position ALIF, and their combination (lateral position LLIF+ALIF). Preliminary studies have validated these methods.

Pharmacogenetic profiling and individualised therapy in the treatment of degenerative spinal conditions

Patients presenting with degenerative spinal changes are often poor surgical candidates due to associated co-morbidities, frailty, or sarcopenia. Additionally, surgeries of a degenerative spine can prove difficult due to the distortion of normal surgical anatomy. Therefore, many patients are managed conservatively with a variety of modalities, including over-the-counter and prescription medications. Nevertheless, several patients do not experience adequate relief from pain with analgesic medications, precipitating multiple hospital visits, and usage of resources. As a result, back pain is regarded as a major economic burden, with total costs of associated treatment exceeding $100 billion annually. Pharmacogenetics is a relatively novel method of evaluating an individual's response to analgesic medications, through analysis of germline polymorphisms. It entails obtaining a genetic sample, often via buccal swab or peripheral blood sample, and genetic analysis achieved through either polymerase chain reaction +/- Sanger sequencing, microassays, restriction length fragment polymorphism analysis, or genetic library preparation and next generation sequencing. The potential efficacy of pharmacogenetic analysis has been highlighted across several specialities to date. However, a paucity of evidence exists regarding spine surgery populations. Nevertheless, regular prospective pharmacogenetic analysis may ultimately prove beneficial when concerning degenerative spinal cohorts due to aforementioned surgical and economic considerations. The purpose of this narrative review is to outline how metaboliser profile variants affect the pharmacokinetics of specific analgesia used to treat back pain, and to discuss the current potential and limitations of employing regular pharmacogenetic analysis for spine surgery populations with degenerative conditions.

The impact of case order and intraoperative staff changes on spine surgical efficiency

BACKGROUND CONTEXT

Despite concerted efforts toward quality improvement in high-volume spine surgery, there remains concern that increases in case load may compromise the efficient and safe delivery of surgical care. There is a paucity of evidence to describe the effects of spine case order and operating room (OR) team structure on measures of intraoperative timing and OR efficiency.

PURPOSE

This study aims to determine if intraoperative staff changes and surgical case order independently predict extensions in intraoperative timing after spinal surgery for spondylotic diseases.

STUDY DESIGN/ SETTING

Retrospective cohort analysis PATIENT SAMPLE: All patients over age 18 who underwent primary or revision decompression and/or fusion for degenerative spinal diseases between 2017 to 2019 at a single academic institution were retrospectively identified. Exclusion criteria included absence of descriptive data and intraoperative timing parameters as well as surgery for traumatic injury, infection, and malignancy.

OUTCOME MEASURES

Intraoperative timing metrics including total theater time, wheels in to induction, induction start to cut, cut to close, and close to wheels out. Postoperative outcomes included length of hospital stay and 90-day hospital readmissions.

METHODS

Surgical case order and intraoperative changes in staff (circulator and surgical scrub nurse or technician) were determined. Patient demographics, surgical factors, intraoperative timing and postoperative outcomes were recorded. Extensions in each operative stage were determined as a ratio of the actual duration of the parameter divided by the predicted duration of the parameter. Univariate and multivariate analyses were performed to compare outcomes within case order and staff change groups.

RESULTS

A total of 1,108 patients met the inclusion criteria. First, second, and third start cases differed significantly in intraoperative extensions of total theater time, wheels in to induction, induction start to cut, cut to close, and close to wheels out. On regression, decreasing case order predicted extension in wheels in to induction time. Surgeries with intraoperative staff changes were associated with increases in total theater time, induction start to cut time, cut to close time, close to wheels out time, and length of hospital stay. Switch in primary circulator predicted extended theater time and cut to close time. Relief of primary circulator or scrub predicted extended total theater time, induction start to cut time, cut to close time, and close to wheels out time.

CONCLUSIONS

Intraoperative staff change in spine surgery independently predicted extended operative duration. However, higher case order was not significantly associated with procedural time.

The Effect of Anterior Cervical Discectomy and Fusion Procedure Duration on Patient-Reported Outcome Measures

OBJECTIVE

To determine whether operative duration of anterior cervical discectomy and fusion (ACDF) significantly affects patient-reported outcome measures (PROMs) 90 days after surgery and at 1-year follow-up.

METHODS

Patients who underwent primary 1-level to 4-level ACDF were retrospectively identified. Demographic data and PROMs were collected through chart review. Patients were split into short, medium, and long tertiles based on procedure duration. PROM surveys were administered preoperatively as baseline measurements, at initial follow-up (between 60 and 120 days postoperatively), and at 1 year postoperatively. Outcomes included Neck Disability Index, Short-Form 12 Physical Component Score (PCS-12), Short-Form 12 Mental Component Score, visual analog scale (VAS) neck score, and VAS arm score.

RESULTS

Significant short-term improvements were found across all groups for all PROMs. All groups showed long-term improvements in Short-Form 12 Mental Component Score, PCS-12, Neck Disability Index, VAS neck score, and VAS arm score, with the exception of the medium-duration group in PCS-12 (P = 0.093). On multivariate analysis, short-duration procedures predicted better improvement in VAS neck score (β = -1.01; P = 0.012) and VAS arm score (β = -1.38; P = 0.002) compared with long-duration procedures, whereas medium-duration procedures resulted in better improvement in VAS arm score (β = -1.00; P = 0.011). Further, short and medium duration was a predictor of decreased length of hospital stay (β = -0.67, P = 0.001 and β = -0.59, P = 0.001, respectively) compared with long-duration procedures.

CONCLUSIONS

All groups improved after ACDF regardless of surgical duration. Further, surgical duration was not a predictor of differing improvement in physical function or disability.

Development of a New Therapy-Oriented Classification of Intervertebral Vacuum Phenomenon With Evaluation of Intra- and Interobserver Reliabilities

STUDY DESIGN

Diagnostic study, level of evidence III.

OBJECTIVES

Low back pain is a common cause of disability among elderly patients. Percutaneous discoplasty has been developed as a tool to treat degenerative disease when conservative management is not successful. Indications for this procedure include low back pain and the presence of vacuum phenomenon. The objective of this study was to describe a new classification of vacuum phenomenon based on computed tomography scan in order to improve the indications for percutaneous discoplasty.

METHODS

We developed a classification of vacuum phenomenon based on computed tomography scan images. We describe 3 types of vacuum based on the relationship between vacuum and the superior/inferior endplates and 2 subtypes based on the presence of significant subchondral sclerosis. A validation study was conducted selecting 10 orthopedic residents with spine surgery training to analyze 25 vacuum scenarios. Inter- and intraobserver reliabilities were assessed through the Fleiss's and Cohen's kappa statistics, respectively.

RESULTS

The overall Fleiss's κ value for interobserver reliability was 0.85 (95% CI 0.82-0.86) in the first reading and 0.93 (95% CI 0.92-0.95) in the second reading. Cohen's κ for intraobserver reliability was 0.88 (95% CI 0.77-0.99).

CONCLUSION

The new classification has shown almost perfect inter- and intraobserver reliabilities for grading the vacuum phenomenon and could be an important tool to improve the indications for percutaneous cement discoplasty.

Perioperative outcomes of reconstructive surgery for apical prolapse in the very elderly: a national contemporary analysis

INTRODUCTION AND HYPOTHESIS

It is predicted that the number of women aged 80 years or older will more than triple by 2050. In the US, women have a 13% lifetime risk of undergoing pelvic organ prolapse surgery. Our aim was to compare the perioperative outcomes following various reconstructive approaches for apical prolapse surgery in the very elderly.

METHODS

The National Surgical Quality Improvement Program database was used to identify women age ≥ 80 years of age who underwent reconstructive apical prolapse surgery from 2010 to 2017. Perioperative morbidity of vaginal colpopexy, minimally invasive sacrocolpopexy (MISC) and abdominal sacrocolpopexy (ASC) were compared. The primary outcome was the rate of composite serious complications. Univariate and multivariate logistic regression was used to identify independent predictors of serious complications.

RESULTS

A total of 1012 patients were identified: vaginal (n = 792), MISC (n = 151) and ASC (n = 69). The composite serious complication rate was higher in the ASC group compared to vaginal/MISC groups (18.8% vs. 9.3% and 9.3%, p < 0.05). ASC had higher rates of blood transfusion, thromboembolism and reintubation. Life-threatening complications, readmission, pneumonia, stroke and 30-day mortality were lowest in the vaginal group. ASC (aOR 2.27), age > 85 years (aOR 1.98), operative time > 3 h (aOR 2.02), baseline dyspnea (aOR 2.17), "other race" (aOR 2.04), preoperative coagulopathy (aOR 2.92) and ASA (aOR 1.47) were associated with composite serious complications.

CONCLUSION

ASC is associated with higher perioperative morbidity in the very elderly population. MISC and vaginal colpopexy have similar rates of composite serious complications; however, vaginal colpopexy is overall the safest approach in this population.

Risk of Postoperative Complications and Revision Surgery Following Robot-assisted Posterior Lumbar Spinal Fusion

STUDY DESIGN

Retrospective Study.

OBJECTIVE

This investigation examined matched cohorts of lumbar spinal fusion (LSF) patients undergoing robot-assisted and conventional LSF to compare risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization.

SUMMARY OF BACKGROUND DATA

Patient outcomes and complication rates associated with robot-assisted LSF compared to conventional fusion techniques are incompletely understood.

METHODS

The PearlDiver Research Program (www.pearldiverinc.com) was used to identify patients undergoing primary LSF between 2011 and 2017. Patients receiving robot-assisted or conventional LSF were matched using key demographic and comorbidity variables. Indication for revision was also studied. Risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization at 1 and 6 months was compared between the cohorts using multivariable logistic regression additionally controlling for age, sex, and Charlson Comorbidity Index.

RESULTS

The percent of LSFs that were robot-assisted rose by 169% from 2011 to 2017, increasing linearly each year (p = 0.0007). Matching resulted in 2528 patients in each cohort for analysis. Robot-assisted LSF patients experienced higher risk of revision (adjusted odds ratio [aOR] = 2.35, P ≤ 0.0001), 30-day readmission (aOR = 1.39, P = 0.0002), and total 30-day complications (aOR = 1.50, P < 0.0001), specifically respiratory (aOR = 1.56, P = 0.0006), surgical site infection (aOR = 1.56, P = 0.0061), and implant-related complications (aOR = 1.74, P = 0.0038). The risk of revision due to infection after robot-assisted LSF was an estimated 4.5-fold higher (aOR = 4.46, 95% confidence interval [CI] 1.95-12.04, P = 0.0011). Furthermore, robot-assisted LSF had increased risk of revision due to instrument failure (aOR = 1.64, 95% CI 1.05-2.58, P = 0.0300), and pseudarthrosis (aOR = 2.24, 95%CI = 1.32-3.95, P = 0.0037). A higher percentage of revisions were due to infection in robot-assisted LSF (19.0%) than in conventional LSF (9.2%) (P = 0.0408).

CONCLUSION

Robotic-assisted posterior LSF is independently associated with increased risk of revision surgery, infection, instrumentation complications, and postoperative opioid utilization compared to conventional fusion techniques. Further research is needed to investigate long-term postoperative outcomes following robot-assisted LSF. Spine surgeons should be cautious when considering immediate adoption of this emerging surgical technology.

LEVEL OF EVIDENCE

3.

Delayed Surgical Intervention in Acute Subdural Hematoma

Background Current guidelines recommend an acute subdural hematoma (ASDH) with a thickness greater than or equal to 10 mm or a midline shift greater than or equal to 5 mm be evacuated regardless of Glasgow Coma Scale (GCS). A large craniotomy versus craniectomy is the preferred surgical treatment for ASDH. A subset of patients who are typically older if not elderly meet the above criteria but have a monitorable neurologic exam. These patients can be followed and taken in a delayed manner allowing the ASDH to become chronic. The delay in treatment allows for a smaller surgery in regards to size of incision, size of craniotomy, and duration of anesthesia.  Methods Between February 2013 and July 2019, we retrospectively identified 19 patients who underwent delayed evacuation of an ASDH, with the primary outcome being Glasgow Outcome Score (GOS) at discharge and three-month follow-up. Results Eight patients (42%) were female and 11 patients (58%) were male. The median age was 77 years, with a range from 49 to 93 years. Sixteen patients (84%) were 60 years of age or older. Mechanism of injury was a fall for 10 patients (53%). Median number of days from initial evaluation and surgical evacuation was 11 days with a range from 6 to 31 days. Thirteen patients (68%) had a GOS of 4-5 at three-month follow-up. Six patients (32%) had a GOS 1-3 at three-month follow-up. Two mortalities (11%) recorded in the postoperative period. Conclusion Surgically evacuated ASDH in the elderly population is known to carry a significant mortality and morbidity. With close neuromonitoring, delayed intervention in older patients with an ASDH, initially meeting surgical criteria with a good neurologic exam, is a safe practice. Delayed treatment allows for smaller surgery, decreased operative time, and decreased surgical risk which affects older patients even more than younger patients.

Rate of failure of indirect decompression in lateral single-position surgery: clinical results

OBJECTIVE

Lateral single-position surgery (LSPS) of the lumbar spine generally involves anterior lumbar interbody fusion (ALIF) performed in the lateral position (LALIF) at L5–S1 with or without lateral lumbar interbody fusion (LLIF) at L4–5 and above, followed by bilateral pedicle screw fixation (PSF) without repositioning the patient. One obstacle to more widespread adoption of LSPS is the perceived need for direct decompression of the neural elements, which typically requires flipping the patient to the prone position. The purpose of this study was to examine the rate of failure of indirect decompression in a cohort of patients undergoing LSPS from L4 to S1.

METHODS

A multicenter, post hoc analysis was undertaken from prospectively collected data of patients at 3 institutions who underwent LALIF at L5–S1 with or without LLIF at L4–5 with bilateral PSF in the lateral decubitus position between March 2018 and March 2020. Inclusion criteria were symptoms of radiculopathy or neurogenic claudication, central or foraminal stenosis (regardless of degree or etiology), and indication for interbody fusion at L5–S1 or L4–S1. Patients with back pain only; those who were younger than 18 years; those with tumor, trauma, or suspicion of infection; those needing revision surgery; and patients who required greater than 2 levels of fusion were excluded. Baseline patient demographic information and surgical data were collected and analyzed. The number of patients in whom indirect decompression failed was recorded and each individual case of failure was analyzed.

RESULTS

A total of 178 consecutive patients underwent LSPS during the time period (105 patients underwent LALIF at L5–S1 and 73 patients underwent LALIF at L5–S1 with LLIF at L4–5). The mean follow-up duration was 10.9 ± 6.5 months. Bilateral PSF was placed with the patient in the lateral decubitus position in 149 patients, and there were 29 stand-alone cases. The mean case time was 101.9 ± 41.5 minutes: 79.3 minutes for single-level cases and 134.5 minutes for 2-level cases. Three patients (1.7%) required reoperation for failure of indirect decompression.

CONCLUSIONS

The rate of failure of indirect decompression in LSPS from L4 to S1 is exceedingly low. This low risk of failure should be weighed against the risks associated with direct decompression as well as the risks of the extra operative time needed to perform this decompression.

Outcomes and Complications With Age in Spondylolisthesis: An Evaluation of the Elderly From the Quality Outcomes Database

STUDY DESIGN

Prospective database analysis.

OBJECTIVE

To assess the effect of age on patient-reported outcomes (PROs) and complication rates after surgical treatment for spondylolisthesis SUMMARY OF BACKGROUND DATA.: Degenerative lumbar spondylolisthesis affects 3% to 20% of the population and up to 30% of the elderly. There is not yet consensus on whether age is a contraindication for surgical treatment of elderly patients.

METHODS

The Quality Outcomes Database lumbar registry was used to evaluate patients from 12 US academic and private centers who underwent surgical treatment for grade 1 lumbar spondylolisthesis between July 2014 and June 2016.

RESULTS

A total of 608 patients who fit the inclusion criteria were categorized by age into the following groups: less than 60 (n = 239), 60 to 70 (n = 209), 71 to 80 (n = 128), and more than 80 (n = 32) years. Older patients showed lower mean body mass index (P < 0.001) and higher rates of diabetes (P = 0.007), coronary artery disease (P = 0.0001), and osteoporosis (P = 0.005). A lower likelihood for home disposition was seen with higher age (89.1% in <60-year-old vs. 75% in >80-year-old patients; P = 0.002). There were no baseline differences in PROs (Oswestry Disability Index, EuroQol health survey [EQ-5D], Numeric Rating Scale for leg pain and back pain) among age categories. A significant improvement for all PROs was seen regardless of age (P < 0.05), and most patients met minimal clinically important differences (MCIDs) for improvement in postoperative PROs. No differences in hospital readmissions or reoperations were seen among age groups (P < 0.05). Multivariate analysis demonstrated that, after controlling other variables, a higher age did not decrease the odds of achieving MCID at 12 months for the PROs.

CONCLUSION

Our results indicate that well-selected elderly patients undergoing surgical treatment of grade 1 spondylolisthesis can achieve meaningful outcomes. This modern, multicenter US study reflects the current use and limitations of spondylolisthesis treatment in the elderly, which may be informative to patients and providers.

LEVEL OF EVIDENCE

4.

Complication avoidance and management in ambulatory spine surgery

The positive safety profile and potential cost savings associated with ambulatory spine surgery have resulted in an increasing number of spine procedures being performed on an outpatient basis. As indications become more inclusive and the variety and volume of ambulatory procedures grow, the incidence of complications may rise. Limiting adverse events in the outpatient setting starts with patient selection. Surgeons should be aware of the potential complications and associated risk factors for common ambulatory spine procedures and employ strategies to limit and appropriately manage them. Protocols which include patient education, multimodal anesthesia and analgesia, standardized post-operative monitoring, and safe discharge planning are also essential for maximizing safety in the ambulatory setting.