Impact of age on comparative outcomes of decompression alone versus fusion for L4 degenerative spondylolisthesis.

PURPOSE: To compare the outcomes of decompression alone and fusion for L4-5 DLS in different age cohorts (< 70 years, ≥ 70 years). METHODS: This retrospective cohort study included patients who underwent minimally invasive decompression or fusion for L4-5 DLS and had a minimum of 1-year follow-up. Outcome measures were: (1) patient-reported outcome measures (PROMs) (Oswestry Disability Index, ODI; Visual Analog Scale back and leg, VAS; 12-Item Short Form Survey Physical Component Score, SF-12 PCS), (2) minimal clinically important difference (MCID), (3) patient acceptable symptom state (PASS), (4) response on the global rating change (GRC) scale, and (5) complication rates. The decompression and fusion groups were compared for outcomes separately in the < 70-year and ≥ 70-year age cohorts. RESULTS: 233 patients were included, out of which 52% were < 70 years. Patients < 70 years showed non-significant improvement in SF-12 PCS and significantly lower MCID achievement rates for VAS back after decompression compared to fusion. Analysis of the ≥ 70-year age cohort showed no significant differences between the decompression and fusion groups in the improvement in PROMs, MCID/PASS achievement rates, and responses on GRC. Patients ≥ 70 years undergoing fusion had significantly higher in-hospital complication rates. When analyzed irrespective of the surgery type, both < 70-year and ≥ 70-year age cohorts showed significant improvement in PROMs with no significant difference. CONCLUSIONS: Patients < 70 years undergoing decompression alone did not show significant improvement in physical function and had significantly less MCID achievement rate for back pain compared to fusion. Patients ≥ 70 years showed no difference in outcomes between decompression alone and fusion.

Loss of lumbar disc height with age and its impact on pain and sensitivity associated behaviors in mice.

PURPOSE: Aging is a risk factor for several debilitating conditions including those related to chronic back pain and intervertebral disc degeneration, both of which have no cure. Mouse models are useful tools for studying disc degeneration and chronic back pain in a tightly controlled and clinically relevant aging environment. Moreover, mice offer the advantage of carrying out longitudinal studies to understand the etiology and progression of disc pathology induced by genetic or surgical strategies. Previously, age-related behavioral trends of discomfort and enhanced nociception in mice were reported; however, whether these measures are mediated by structural and pathological changes in the disc is unknown. METHODS: The goal of the present observational study was to identify behavioral correlates of age-related degenerative changes in the disc. Towards this, we collected radiographs from 150 mice (77 females) between three and 23 months of age and measured the disc height index for each level of lumbar disc. Behavioral measures were collected on several of these mice which included rearing and distance travelled in an open field test; time spent in rearing, reaching, immobile, and self-suspended in the tail suspension test; bilateral hind paw licking in response to cold allodynia using acetone; and unilateral hind paw licking in response to heat hyperalgesia using capsaicin. RESULTS: Results show that the lower lumbar discs lose height with age and these changes are independent of body composition measures including body weight, bone mineral density, fat mass, lean weight mass, percent fat mass, and percent lean mass. Disc height positively correlates with rearing and mobility in the open field test, immobility in the tail suspension test, and thermal hyperalgesia. Disc height negatively correlates with cold allodynia and rearing in the tail suspension test. Furthermore, mediation analysis shows that the lumbosacral disc significantly mediates the effect of age on rearing in the open field test, but not cold allodynia, suggesting this behavior is a useful measure of age-related axial discomfort due to disc degeneration. CONCLUSION: In summary, the findings from the current study show that disc height are associated with measures of axial discomfort and nociception in mice.

How Do Areas of Work Life Drive Burnout in Orthopaedic Attending Surgeons, Fellows, and Residents?

BACKGROUND: Concerning levels of burnout have been reported among orthopaedic surgeons and residents. Defined as emotional exhaustion and depersonalization, physician burnout is associated with decreased productivity, increased medical errors, and increased risk of suicidal ideation. At the center of burnout research, person-centered approaches focusing on individual characteristics and coping strategies have largely been ineffective in solving this critical issue. They have failed to capture and address important institutional and organizational factors contributing to physician burnout. Similarly, little is known about the relationship between burnout and the working environments in which orthopaedic physicians practice, and on how orthopaedic surgeons at different career stages experience and perceive factors relevant to burnout. QUESTIONS/PURPOSES: (1) How does burnout differ among orthopaedic attending surgeons, fellows, and residents? (2) What specific areas of work life are problematic at each of these career stages? (3) What specific areas of work life correlate most strongly with burnout at each of these career stages? METHODS: Two hundred orthopaedic surgeons (residents, fellows, and attending physicians) at a single institution were invited to complete an electronic survey. Seventy-four percent (148 of 200) of them responded; specifically, 43 of 46 residents evenly distributed among training years, 18 of 36 fellows, and 87 of 118 attending physicians. Eighty-three percent (123 of 148) were men and 17% (25 of 148) were women. Two validated questionnaires were used. The Maslach Burnout Inventory was used to assess burnout, measuring emotional exhaustion and depersonalization. The Areas of Worklife Survey was used to measure congruency between participants and their work environment in six domains: workload, control, reward, community, fairness, and values. Participants were invited to openly share their experiences and suggest ways to improve burnout and specific work life domains. The main outcome measures were Maslach Burnout Inventory subdomains of emotional exhaustion and depersonalization, and Areas of Worklife Survey subdomains of workload, control, reward, community, fairness and values. We compared outcome measures of burnout and work life between groups. Simple linear regression models were used to report correlations between subscales. Stratified analyses were used to identify which group demonstrated higher correlations. All open comments were analyzed and coded to fully understand which areas of work life were problematic and how they were perceived in our population. RESULTS: Nine percent (7 of 80) of attending surgeons, 6% (1 of 16) of fellows, and 34% (14 of 41) of residents reported high levels of depersonalization on the Maslach Burnout Inventory (p < 0.001). Mean depersonalization scores were higher (worse) in residents followed by attending surgeons, then fellows (10 ± 6, 5 ± 5, 4 ± 4 respectively; p < 0.001). Sixteen percent (13 of 80) of attending surgeons, 31% (5 of 16) of fellows, and 34% (14 of 41) of residents reported high levels of emotional exhaustion (p = 0.07). Mean emotional exhaustion scores were highest (worse) in residents followed by attending surgeons then fellows (21 ± 12, 17 ± 10, 16 ± 14 respectively; p = 0.11). Workload was the most problematic work life area across all stages of orthopaedic career. Scores in the Areas of Worklife Survey were the lowest (worse) in the workload domain for all subgroups: residents (2.6 ± 0.4), fellows (3.0 ± 0.6), and attending surgeons (2.8 ± 0.7); p = 0.08. Five problematic work life categories were found through open comment analysis: workload, resources, interactions, environment, and self-care. Workload was similarly the most concerning to participants. Specific workload issues identified included administrative load (limited job control, excessive tasks and expectations), technology (electronic medical platform, email overload), workflow (operating room time, patient load distribution), and conflicts between personal, clinical, and academic roles. Overall, worsening emotional exhaustion and depersonalization were most strongly associated with increasing workload (r = - 0.50; p < 0.001; and r = - 0.32; p < 0.001, respectively) and decreasing job control (r = - 0.50; p < 0.001, and r = - 0.41; p < 0.001, respectively). Specifically, in residents, worsening emotional exhaustion and depersonalization most strongly correlated with increasing workload (r = - 0.65; p < 0.001; and r = - 0.53; p < 0.001, respectively) and decreasing job control (r = - 0.49; p = 0.001; and r = - 0.51; p = 0.001, respectively). In attending surgeons, worsening emotional exhaustion was most strongly correlated with increasing workload (r = - 0.50; p < 0.001), and decreasing job control (r = - 0.44; p < 0.001). Among attending surgeons, worsening depersonalization was only correlated with increasing workload (r = - 0.23; p = 0.04). Among orthopaedic fellows, worsening emotional exhaustion and depersonalization were most strongly correlated with decreasing sense of fairness (r = - 0.76; p = 0.001; and r = - 0.87; p < 0.001, respectively), and poorer sense of community (r = - 0.72; p = 0.002; and r = - 0.65; p = 0.01, respectively). CONCLUSIONS: We found higher levels of burnout among orthopaedic residents compared to attending surgeons and fellows. We detected strong distinct correlations between emotional exhaustion, depersonalization, and areas of work life across stages of orthopaedic career. Burnout was most strongly associated with workload and job control in orthopaedic residents and attending surgeons and with fairness and community in orthopaedic fellows. CLINICAL RELEVANCE: Institutions wishing to better understand burnout may use this approach to identify specific work life drivers of burnout, and determine possible interventions targeted to orthopaedic surgeons at each stage of career. Based on our institutional experience, leadership should investigate strategies to decrease workload by increasing administrative support and improving workflow; improve sense of autonomy by consulting physicians in decision-making; and seek to improve the sense of control in residents and sense of community in fellows.

Effect of Ventral vs Dorsal Spinal Surgery on Patient-Reported Physical Functioning in Patients With Cervical Spondylotic Myelopathy: A Randomized Clinical Trial.

Importance: Cervical spondylotic myelopathy is the most common cause of spinal cord dysfunction worldwide. It remains unknown whether a ventral or dorsal surgical approach provides the best results. Objective: To determine whether a ventral surgical approach compared with a dorsal surgical approach for treatment of cervical spondylotic myelopathy improves patient-reported physical functioning at 1 year. Design, Setting, and Participants: Randomized clinical trial of patients aged 45 to 80 years with multilevel cervical spondylotic myelopathy enrolled at 15 large North American hospitals from April 1, 2014, to March 30, 2018; final follow-up was April 15, 2020. Interventions: Patients were randomized to undergo ventral surgery (n = 63) or dorsal surgery (n = 100). Ventral surgery involved anterior cervical disk removal and instrumented fusion. Dorsal surgery involved laminectomy with instrumented fusion or open-door laminoplasty. Type of dorsal surgery (fusion or laminoplasty) was at surgeon's discretion. Main Outcomes and Measures: The primary outcome was 1-year change in the Short Form 36 physical component summary (SF-36 PCS) score (range, 0 [worst] to 100 [best]; minimum clinically important difference = 5). Secondary outcomes included 1-year change in modified Japanese Orthopaedic Association scale score, complications, work status, sagittal vertical axis, health resource utilization, and 1- and 2-year changes in the Neck Disability Index and the EuroQol 5 Dimensions score. Results: Among 163 patients who were randomized (mean age, 62 years; 80 [49%] women), 155 (95%) completed the trial at 1 year (80% at 2 years). All patients had surgery, but 5 patients did not receive their allocated surgery (ventral: n = 1; dorsal: n = 4). One-year SF-36 PCS mean improvement was not significantly different between ventral surgery (5.9 points) and dorsal surgery (6.2 points) (estimated mean difference, 0.3; 95% CI, -2.6 to 3.1; P = .86). Of 7 prespecified secondary outcomes, 6 showed no significant difference. Rates of complications in the ventral and dorsal surgery groups, respectively, were 48% vs 24% (difference, 24%; 95% CI, 8.7%-38.5%; P = .002) and included dysphagia (41% vs 0%), new neurological deficit (2% vs 9%), reoperations (6% vs 4%), and readmissions within 30 days (0% vs 7%). Conclusions and Relevance: Among patients with cervical spondylotic myelopathy undergoing cervical spinal surgery, a ventral surgical approach did not significantly improve patient-reported physical functioning at 1 year compared with outcomes after a dorsal surgical approach. Trial Registration: ClinicalTrials.gov Identifier: NCT02076113.

Morphometric analysis of cervical interlaminar space for posterior surgical approach and decompression.

PURPOSE: The purpose of this study is to provide a morphometric description of the bony margins of the interlaminar spaces by level in the cervical spine for guidance of safe posterior cervical surgical dissection and decompression. We also aim to describe the impact of increasing static cervical lordosis on the overlap between the lamina. METHODS: Morphometric measurements of the interlaminar space were performed on 100 consecutive cervical spine CT scans of patients ranging in age from 18 to 50 years were selected. Three raters performed measurements of the interlaminar height measured using two techniques (true interlaminar height and surgical interlaminar height), and interlaminar width from C2-C3 to C7-T1. RESULTS: In total, 100 patients were included. The true interlaminar height was greatest at C2-3, C3-4, C4-5 (5.2 ± 1.4-1.8 mm) and smallest at C6-7 (4.4 ± 1.3 mm). Surgical interlaminar height was greatest at C3-4 (4.2 ± 1.7) and smallest at C6-7 (3.0 ± 1.3 mm). The widest interlaminar space was observed at C3-4 (27.1 ± 2.1 mm) and most narrow at C7-T1 (20.9 ± 2.4 mm). Following multivariate regression, male gender was associated with greater interlaminar widths at each cervical level between C4 and T1 (Table 2). While greater patient height was associated with larger interlaminar height (true and surgical) and width at C2-3 and C4-5, weight was not independently associated with the interlaminar measurements. Increasing C2-C7 lordosis was significantly associated with decreasing true and surgical interlaminar heights at all levels except C7-T1, but was not associated with differences between interlaminar width. CONCLUSION: The study provides a morphometric analysis of interlaminar anatomy in the cervical spine. Surgeons can apply this information in their pre-operative plan to safely approach the posterior cervical spine.

Does interbody cage lordosis impact actual segmental lordosis achieved in minimally invasive lumbar spine fusion?

OBJECTIVE: In an effort to prevent loss of segmental lordosis (SL) with minimally invasive interbody fusions, manufacturers have increased the amount of lordosis that is built into interbody cages. However, the relationship between cage lordotic angle and actual SL achieved intraoperatively remains unclear. The purpose of this study was to determine if the lordotic angle manufactured into an interbody cage impacts the change in SL during minimally invasive surgery (MIS) for lumbar interbody fusion (LIF) done for degenerative pathology. METHODS: The authors performed a retrospective review of a single-surgeon database of adult patients who underwent primary LIF between April 2017 and December 2018. Procedures were performed for 1-2-level lumbar degenerative disease using contemporary MIS techniques, including transforaminal LIF (TLIF), lateral LIF (LLIF), and anterior LIF (ALIF). Surgical levels were classified on lateral radiographs based on the cage lordotic angle (6°-8°, 10°-12°, and 15°-20°) and the position of the cage in the disc space (anterior vs posterior). Change in SL was the primary outcome of interest. Subgroup analyses of the cage lordotic angle within each surgical approach were also conducted. RESULTS: A total of 116 surgical levels in 98 patients were included. Surgical approaches included TLIF (56.1%), LLIF (32.7%), and ALIF (11.2%). There were no differences in SL gained by cage lordotic angle (2.7° SL gain with 6°-8° cages, 1.6° with 10°-12° cages, and 3.4° with 15°-20° cages, p = 0.581). Subgroup analysis of LLIF showed increased SL with 15° cages only (p = 0.002). The change in SL was highest after ALIF (average increase 9.8° in SL vs 1.8° in TLIF vs 1.8° in LLIF, p < 0.001). Anterior position of the cage in the disc space was also associated with a significantly greater gain in SL (4.2° vs -0.3°, p = 0.001), and was the only factor independently correlated with SL gain (p = 0.016). CONCLUSIONS: Compared with cage lordotic angle, cage position and approach play larger roles in the generation of SL in 1-2-level MIS for lumbar degenerative disease.

Opioid-free anesthesia within an enhanced recovery after surgery pathway for minimally invasive lumbar spine surgery: a retrospective matched cohort study.

OBJECTIVEEnhanced recovery after surgery (ERAS) and multimodal analgesia are established care models that minimize perioperative opioid consumption and promote positive outcomes after spine surgery. Opioid-free anesthesia (OFA) is an emerging technique that may achieve similar goals. The purpose of this study was to evaluate an OFA regimen within an ERAS pathway for lumbar decompressive surgery and to compare perioperative opioid requirements in a matched cohort of patients managed with traditional opioid-containing anesthesia (OCA).METHODSThe authors performed a retrospective analysis of prospectively collected data. They included 36 patients who underwent lumbar decompression under their ERAS pathway for spinal decompression between February and August 2018. Eighteen patients who received OFA were matched in a 1:1 ratio to a cohort managed with a traditional OCA regimen. The primary outcome was total perioperative opioid consumption. Postoperative pain scores (measured using the numerical rating scale [NRS]), opioid consumption (total morphine equivalents), and length of stay (time to readiness for discharge) were compared in the postanesthesia care unit (PACU). The authors also assessed compliance with ERAS process measures and compared compliance during 3 phases of care: pre-, intra-, and postoperative.RESULTSThere was a significant reduction in total perioperative opioid consumption in patients who received OFA (2.43 ± 0.86 oral morphine equivalents [OMEs]; mean ± SEM), compared to patients who received OCA (38.125 ± 6.11 OMEs). There were no significant differences in worst postoperative pain scores (NRS scores 2.55 ± 0.70 vs 2.58 ± 0.73) or opioid consumption (5.28 ± 1.7 vs 4.86 ± 1.5 OMEs) in the PACU between OFA and OCA groups, respectively. There was a clinically significant decrease in time to readiness for discharge from the PACU associated with OFA (37 minutes), although this was not statistically significantly different. The authors found high overall compliance with ERAS process measures (91.4%) but variation in compliance according to phase of care. The highest compliance occurred during the preoperative phase (94.71% ± 2.88%), and the lowest compliance occurred during the postoperative phase of care (85.4% ± 5.7%).CONCLUSIONSOFA within an ERAS pathway for lumbar spinal decompression represents an opportunity to minimize perioperative opioid exposure without adversely affecting pain control or recovery. This study reveals opportunities for patient and provider education to reinforce ERAS and highlights the postoperative phase of care as a time when resources should be focused to increase ERAS adherence.

An enhanced recovery after surgery pathway: association with rapid discharge and minimal complications after anterior cervical spine surgery.

OBJECTIVEEnhanced recovery after surgery (ERAS) pathways are associated with improved outcomes, lower morbidity and complications, and higher patient satisfaction in multiple surgical subspecialties. Despite these gains, there are few data to guide the application of ERAS concepts to spine surgery. The authors report the development and implementation of the first ERAS pathway for patients undergoing anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA).METHODSThis was a retrospective cohort study of prospectively collected data. The authors created a multidisciplinary pathway based on best available evidence for interventions that positively influence outcomes after anterior cervical spine surgery. Patients were followed prospectively up to postoperative day 90. Patient data were collected via electronic medical record review and included demographics, comorbidities, baseline and perioperative opioid use, postoperative complications, and length of hospital stay (LOS). ERAS process measures and compliance with pathway elements were also tracked.RESULTSThirty-three patients were cared for under the pathway (n = 25 ACDF; n = 8 CDA). The median LOS was 416 minutes (interquartile range [IQR] 210-1643 minutes). Eight patients required an extended stay-longer than 23 hours. Reasons for extended admission included pain (n = 4), dyspnea (n = 1), hypoxia (n = 1), hypertension (n = 1), and dysphagia (n = 1). The median LOS for the 8 patients who required extended monitoring prior to discharge was 1585 minutes (IQR 1423-1713 minutes). Overall pathway compliance with included process measures was 85.6%. The median number of ERAS process elements delivered to each patient was 18. There was no strong association between LOS and number of ERAS process elements provided (Pearson's r = -0.20). Twelve percent of the cohort was opioid tolerant on the day of surgery. There were no significant differences between total intraoperatively or postanesthesia care unit-administered opioid, or LOS, between opioid-tolerant and opioid-naïve patients. There were no complications requiring readmission.CONCLUSIONSAn ERAS pathway for anterior cervical spine surgery facilitates safe, prompt discharge. The ERAS pathway was associated with minimal complications, and no readmissions within 90 days of surgery. Pain and respiratory compromise were both linked with extended LOS in this cohort. Further prospective studies are needed to confirm the potential benefits of ERAS for anterior cervical spine surgery, including longer-term complications, cost, and functional outcomes.

New Paradigms in the Continuum of Spine Care: From Newborns to Elderly Patients.

The evaluation and management of spinal disorders is complex and constantly evolving. Back pain and spinal deformity are substantial contributors to hospital and outpatient physician visits even for young patients. With new insights into the etiology, clinical presentation, and evaluation, children can be more accurately diagnosed and treated. Patients with adolescent idiopathic scoliosis may undergo selective fusion to preserve motion segments, and in some cases, vertebral body tethering or other growth-modification techniques may provide correction with motion preservation in this rapidly changing specialty. The understanding of spinopelvic parameters (pelvic incidence, pelvic tilt, sacral slope) and sagittal balance as they relate to clinical health status has provided surgeons with valuable guidance when managing pediatric and adult spinal deformity. An evidence-based approach to the management of spinal disorders across the continuum of ages has the goal of improving the value of care through optimization of outcomes and limitation of costs and complications. There are new paradigms in the management of spinal disorders and evidence-based approaches to the evaluation and management of patients across the ages.

Lumbar disc herniation: what has the Spine Patient Outcomes Research Trial taught us?

INTRODUCTION: Intervertebral disc herniation (IDH) can cause back pain and/or radiculopathy and accounts for a significant portion of patients having spinal surgery in the USA. One of the most impactful and well-executed randomized trials to study diagnosis, treatments, and outcomes in patients with three commonly treated spinal conditions was the Spine Patient Outcomes Research Trial (SPORT). This study and the subsequent data analyses have resulted in numerous publications related to IDH. The purpose of this review is to summarize SPORT publications with IDH results to better understand what we have learned from this important landmark trial. METHODS: Publications utilizing SPORT data that reported findings related to IDH patients were identified from Medline, PubMed, and PubMed Central. The primary findings pertaining to IDH were summarized. RESULTS: There were 25 studies identified reporting findings related to IDH from the SPORT data published between 2004 and 2017. Publications in the following areas were summarized: epidemiology and baseline patient characteristics (1), treatment preferences and expectations (2), radiological and MRI (3), primary study objectives at two years (2), four years (1) and eight years (1), subgroup analyses (13), cost-effectiveness (1), and reherniation (1). CONCLUSIONS: This report reviewed the current state of SPORT publications related to IDH to identify and summarize what we have learned about diagnosis, patient characteristics, treatments, outcomes, and cost-effectiveness in patients with lumbar disc herniations. Many important findings are now published from this robust trial's data. Clinicians should incorporate these results into their clinical decision-making and during counseling patients presenting with lumbar disc herniations.

Radiographic variables that may predict clinical outcomes in cervical disk replacement surgery.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVE: To determine which, if any, radiographic parameters are predictive of clinical outcome after cervical disk replacement (CDR) surgery. SUMMARY OF BACKGROUND DATA: It is unclear whether radiographic parameters are predictive of outcome after CDR. METHODS: An analysis of the radiographic parameters and clinical outcomes of the CDR cohort of the Discover artificial cervical disk IDE trial was performed. Clinical outcome measures included Neck Disability Index (NDI), visual analog pain scale (neck, arm, and shoulder), and SF-36 physical component summary score scores, collected preoperatively and at regularly scheduled postoperative time periods. Patients with at least 1-year follow-up were included. The change in outcomes from baseline was determined at each follow-up interval. The following minimal clinically important difference (MCID) thresholds were applied: -7.5 for NDI, -25 for visual analog pain scale, and +4.1 for physical component summary score. Fifty-six radiographic variables were analyzed to identify factors that may be associated with a poor clinical outcome, defined as failure to achieve the MCID in NDI. RESULTS: A total of 243 patients underwent CDR at 304 levels (182 one level, 61 two level). One hundred seventy-one patients (89 female, 82 male; mean age, 44.2 y; range, 28-67 y) had at least 1-year follow-up. A preoperative disk height of <3.5 mm was associated with a 3.4 times greater risk of not achieving a MCID in NDI (P=0.018). Increasing the functional spinal unit angle by >3 degrees was associated with a 3.5 times greater risk of not achieving a MCID in NDI (P=0.016). There were 21/171 patients (25 levels) who did not achieve the NDI MCID threshold. All of these patients had at least1, and 16/21 of these patients had more than 1 abnormal radiographic finding. Seventy percent of treatment levels had severe or bridging heterotopic ossification at 3-years follow-up, the incidence of which increased linearly with time. CONCLUSIONS: Several radiographic variables are predictive of clinical outcomes, including decreased preoperative disk space height and excessive postoperative segmental lordosis.

Disc space preparation in transforaminal lumbar interbody fusion: a comparison of minimally invasive and open approaches.

BACKGROUND: Minimally invasive surgical (MIS) approaches to transforaminal lumbar interbody fusion (TLIF) have been developed as an alternative to the open approach. However, concerns remain regarding the adequacy of disc space preparation that can be achieved through a minimally invasive approach to TLIF. QUESTIONS/PURPOSES: The purpose of this cadaver study is to compare the adequacy of disc space preparation through MIS and open approaches to TLIF. Specifically we sought to compare the two approaches with respect to (1) the time required to perform a discectomy and the number of endplate violations; (2) the percentage of disc removed; and (3) the anatomic location where residual disc would remain after discectomy. METHODS: Forty lumbar levels (ie, L1-2 to L5-S1 in eight fresh cadaver specimens) were randomly assigned to open and MIS groups. Both surgeons were fellowship-trained spine surgeons proficient in the assigned approach used. Time required for discectomy, endplate violations, and percentage of disc removed by volume and mass were recorded for each level. A digital imaging software program (ImageJ; US National Institutes of Health, Bethesda, MD, USA) was used to measure the percent disc removed by area for the total disc and for each quadrant of the endplate. RESULTS: The open approach was associated with a shorter discectomy time (9 versus 12 minutes, p = 0.01) and fewer endplate violations (one versus three, p = 0.04) when compared with an MIS approach, percent disc removed by volume (80% versus 77%, p = 0.41), percent disc removed by mass (77% versus 75%, p = 0.55), and percent total disc removed by area (73% versus 71%, p = 0.63) between the open and MIS approaches, respectively. The posterior contralateral quadrant was associated with the lowest percent of disc removed compared with the other three quadrants in both open and MIS groups (50% and 60%, respectively). CONCLUSIONS: When performed by a surgeon experienced with MIS TLIF, MIS and open approaches are similar in regard to the adequacy of disc space preparation. The least amount of disc by percentage is removed from the posterior contralateral quadrant regardless of the approach; surgeons should pay particular attention to this anatomic location during the discectomy portion of the procedure to minimize the likelihood of pseudarthrosis.

Minimally invasive versus open posterior lumbar interbody fusion: a systematic review.

BACKGROUND: Although conventional open posterior lumbar interbody fusion (open PLIF) is efficacious in management of lumbar spinal instability, concerns exist regarding lengthy hospital stays, blood loss, and postoperative complications. Minimally invasive posterior lumbar interbody fusion (MIS PLIF) may be able to address these concerns, but the research on this topic has not been systematically reviewed. QUESTIONS/PURPOSES: We performed a systematic review to determine whether MIS PLIF or open PLIF results in (1) better perioperative parameters, including blood loss, operative times, and length of hospital stay; (2) improved patient-reported outcome scores; and (3) improved disc distraction and (4) frequency of reoperation and complications when compared with open PLIF procedures. METHODS: A literature search of the MEDLINE database identified seven studies that met our inclusion criteria. A total of seven articles were included; quality was assessed using the Methodological Index for Non-Randomised Studies (MINORS) scale. Descriptive statistics were used to describe the included articles. RESULTS: In most studies, MIS PLIF was associated with decreased blood loss and shorter hospital stay but longer operative times. MIS PLIF resulted in better patient-related outcomes when compared with open PLIF in two studies in the short term, but most of the studies in this review found no short-term differences, and there was no difference at long-term followup in any studies. There was no significant difference in disc distraction. Both techniques appeared to have similar complication rates and reoperation rates. CONCLUSIONS: Based on the available evidence, which we restricted to prospective and retrospective studies with control groups, but did not include any well-designed randomized trials, MIS PLIF might lead to better perioperative parameters, but there was little evidence for improved patient-reported outcomes in the MIS groups. Randomized controlled trials are needed to compare these two surgical techniques.

An algorithmic strategy for selecting a surgical approach in cervical deformity correction.

Adult degenerative cervical kyphosis is a debilitating disease that often requires complex surgical management. Young spine surgeons, residents, and fellows are often confused as to which surgical approach to choose due to lack of experience, absence of a systematic method of surgical management, and today's plethora of information regarding surgical techniques. Although surgeons may be able to perform anterior, posterior, or combined (360°) approaches to the cervical spine, many struggle to rationally choose an appropriate approach for deformity correction. The authors introduce an algorithm based on morphology and pathology of adult cervical kyphosis to help the surgeon select the appropriate approach when performing cervical deformity surgery. Cervical deformities are categorized into 5 different prevalent morphological types encountered in clinical settings. A surgical approach tailored to each category/type of deformity is then discussed, with a concrete case illustration provided for each. Preoperative assessment of kyphosis, determination of the goal for surgery, and the complications associated with cervical deformity correction are also summarized. This article's goal is to assist with understanding the big picture for surgical management in cervical spinal deformity.

Deviation analysis of C1-C2 transarticular screw placement assisted by a novel rapid prototyping drill template: a cadaveric study.

STUDY DESIGN: Cadaveric study. OBJECTIVE: The aim of this study was to develop and validate the accuracy of a novel navigational template for C1-C2 transarticular screw (C1C2TAS) placement in cadaveric specimens. SUMMARY OF BACKGROUND DATA: Currently, C1C2TASs are primarily positioned using a free-hand technique or under fluoroscopic guidance. Screw placement is challenging owing to the small size of the C2 isthmus, which places technical demands on the surgeon. Screw insertion carries a potential risk of neurovascular injury, magnifying the importance of using a precise technique for screw insertion. MATERIALS AND METHODS: Computed tomography (CT) scans with 0.625-mm wide cuts were obtained from the 32 cadaveric cervical specimens. The CT data were imported into a computer navigation system. We developed 32 three-dimensional drill templates, which were created by computer modeling using a rapid prototyping technique based on the CT data. We constructed drill templates using a custom trajectory for each level and side based on specimen anatomy. The drill templates were used to guide establishment of a pilot hole for screw placement. The entry point and angular direction of the intended screw positions and inserted screw positions were measured by comparing postoperative and preoperative images after the coordinate axes were synchronized. RESULTS: The average displacement of the entry point of the left and right C1C2TAS in the x-, y-, and z-axis was 0.13±0.90 mm, 0.50±1.50 mm, and -0.22±0.71 mm on the left, and 0.21±1.03 mm, 0.46±1.55 mm, and -0.29±0.58 mm on the right. There was no statistically significant difference in entry point and direction between the intended and actual screw trajectory. CONCLUSIONS: The small deviations seen are likely due to human error in the form of small variations in the surgical technique and use of software to design the prototype. This technology improves the safety profile of this fixation technique and should be further studied in clinical applications.

Function-preserving reduction and fixation of unstable Jefferson fractures using a C1 posterior limited construct.

STUDY DESIGN: This is a retrospective, clinical, and radiologic study of posterior reduction and fusion of the C1 arch in the treatment of unstable Jefferson fractures. OBJECTIVE: The aim of the study was to describe a new motion-preserving surgical technique in the treatment of unstable Jefferson fracture. SUMMARY OF BACKGROUND DATA: The management of unstable Jefferson fractures remains controversial. The majority of C1 fractures can be effectively treated nonoperatively with external immobilization unless there is an injury to the transverse atlantal ligament (TAL). Conservative treatment usually involves immobilization for a long time in Halo vest, whereas surgical intervention generally involves C1-C2 fusion, eliminating the range of motion of the upper cervical spine. We propose a novel method for the treatment of unstable Jefferson fractures without restricting the range of motion. METHODS: A retrospective review of 12 patients with unstable C1 fractures between April 2008 and October 2011 was performed. They were treated by inserting bilateral posterior C1 pedicle screws or lateral mass screws interconnected by a transversal rod to achieve internal fixation. There were 8 men and 4 women, with an average age of 35.6 years (range, 20-60 y). Presenting symptoms included neck pain, stiffness, and decreased range of motion but none had neurological injury. Seven patients had bilateral posterior arch fractures associated with unilateral anterior arch fractures (posterior 3/4 Jefferson fracture, Landells type II), and 5 had unilateral anterior and posterior arch fractures (half-ring Jefferson fracture, Landells type II). Seven patients had intact TAL, and 5 patients had fractures and avulsion of the attachment of TAL (Dickman type II). RESULTS: A total of 24 screws were inserted. Five cases had screws placed in the lateral mass: 3 because of posterior arch breakage, and 2 because the height of the posterior arch at the entry point was <4 mm. The remaining 7 cases had pedicle screw fixation. One patient had venous plexus injury during exposure of lower margin of the posterior arch; however, successful hemostasis was achieved with Gelfoam. Postoperative x-ray and computed tomography scan showed partial breach of the transverse foramen caused by a screw in 1 case, and breach of the inner cortex of the pedicle caused by screw displacement in 1 case; however, no spinal cord injury or vertebral artery injury was found. The remaining screws were in good position. Patients were followed up for 6-40 months (average, 22 mo). All cases had recovery of range of motion of the cervical spine to the preinjury level by 3-6 months after surgery, with resolution of pain. At 6 months follow-up, plain radiographs and computed tomography scans revealed satisfactory cervical alignment, no implant failure, and satisfactory bony fusion of the fractures; no C1-C2 instability was observed on the flexion-extension radiographs. CONCLUSIONS: C1 posterior limited construct is a valid technique and a feasible method for treating unstable Jefferson fractures, which allows preservation of the function of the craniocervical junction, without significant morbidity.

Cervical laminectomy width and spinal cord drift are risk factors for postoperative C5 palsy.

BACKGROUND: Cervical laminectomy and fusion (CLF) is a treatment option for multilevel cervical spondylotic myelopathy. Postoperative C5 nerve palsy is a possible complication of CLF. It has been suggested that C5 nerve palsy may be due to posterior drift of the spinal cord related to a wide laminectomy trough. PURPOSE: To test the hypothesis that excessive spinal cord drift into a wide laminectomy trough is associated with C5 palsy. STUDY DESIGN: Retrospective case-control study. PATIENT SAMPLE: Seventeen patients with C5 palsy, 8 patients as control group. OUTCOME MEASURES: Spinal cord positional measurements on magnetic resonance imaging (MRI). METHODS: All patients who underwent elective CLF for cervical spondylotic myelopathy or ossified posterior longitudinal ligament using posterior instrumentation between 2004 and 2008 were included. Patients who underwent CLF for trauma, infection, or tumors were excluded. Clinical and radiographic outcomes were assessed by chart review (minimum of 1 y follow-up). Patients who developed a new postoperative C5 nerve palsy underwent repeat MRI. The control group also underwent CLF, did not develop a neurological deficit, and received a postoperative MRI for evaluation of possible infection. MRI measurements included the width of the laminectomy trough, the distance from the posterior vertebral body or disk to the anterior spinal cord, the width of the spinal cord herniated into the laminectomy defect, and C2-7 sagittal alignment. Preoperative radiographic measurements included preoperative vertebral body diameter, spinal canal diameter, and sagittal vertical offset. RESULTS: There were seventeen patients with C5 nerve root palsy and 8 patients without C5 nerve root palsy. There were no baseline differences in fusion levels, instrumentation used, patient age, or sex. MRI measurements revealed an increase in mean postoperative cord drift in patients with C5 palsy at C3 (4.2 vs. 2.2 mm, P=0.002), C4 (4.6 vs. 2.8 mm, P=0.056), C5 (5.1 vs. 2.4 mm, P=0.011), and C6 (5.2 vs. 2.4 mm, P=0.003). There was a significant increase in C5 laminectomy trough width among patients with postoperative C5 palsy (17.9 vs. 15.2 mm, P=0.032), but there was no difference in sagittal alignment. CONCLUSIONS: A wider laminectomy at C5 was associated with an increased risk of postoperative C5 palsy. Increased preoperative spinal canal diameter is also associated with increased risk of C5 palsy. In addition, patients who experienced C5 nerve palsy had a significantly greater posterior spinal cord drift. Strategies to reduce postoperative laminectomy trough width and spinal cord drift may reduce the risk of postoperative C5 palsy.

Elective Single-Level Primary Anterior Cervical Decompression and Fusion for Degenerative Spondylotic Cervical Myelopathy is Associated With Decreased Resource Utilization Versus Posterior Cervical Decompression and Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare elective single-level anterior cervical discectomy and fusion (ACDF) versus posterior cervical decompression and fusion (PCDF) for degenerative cervical myelopathy (DCM) in terms of (1) cost, (2) length of hospital stay, and (3) discharge destination in Medicare patients. A sub-analysis of potential cost drivers was also performed. BACKGROUND: In the era of value-based medicine, there is substantial interest in reducing the cost of care. Both ACDF and PCDF are used to treat DCM but carry different morbidity and risk profiles that can impact hospital resource utilization. However, this has not been assessed on a national level. METHODS: Patients undergoing single-level elective ACDF and PCDF surgery were identified using the 2019 Medicare Provider Analysis and Review (MedPAR) Limited Data Set (LDS) and Centers for Medicare and Medicaid Services (CMS) 2019 Impact File. Multivariate models of hospital cost of care, length of stay, and discharge destination were performed, controlling for confounders. A univariate sub-analysis of 9 revenue centers was performed. RESULTS: In all, 3942 patients met the inclusion criteria. The mean cost of elective single-level cervical fusion for myelopathy was $18,084±10,783, and the mean length of stay was 2.45±2.95 d. On multivariate analysis, ACDF was independently associated with decreased cost of $5,814 (P<0.001), shorter length of stay by 1.1 days (P<0.001), and decreased risk of nonhome discharge destination by 58% (adjusted odds ratio: 0.422, P<0.001).On sub-analysis of 9 revenue centers, medical/surgical supply ($10,497, 44%), operating room charges ($5401, 23%), and accommodations ($3999, 17%) were the largest drivers of charge differences. CONCLUSIONS: Single-level elective primary ACDF for DCM was independently associated with decreased cost, decreased hospital length of stay, and a lower rate of nonhome discharge compared with PCDF. Medical and surgical supply, operating room, and accommodation differences between ACDF and PCDF are potential areas for intervention. Increased granularity in reimbursement structures is warranted to prevent the creation of disincentives to the treatment of patients with DCM with pathology that is better addressed with PCDF. LEVEL OF EVIDENCE: Level-III Retrospective Cohort Study.