Comparative analysis of perioperative characteristics and early outcomes in transforaminal endoscopic lumbar diskectomy: general anesthesia versus conscious sedation.

PURPOSE: To better understand how anesthesia type impacts patient selection and recovery in TELD, we conducted a multicenter prospective study which evaluates the differences in perioperative characteristics and outcomes between patients who underwent TELD with either general anesthesia (GA) or conscious sedation (CS). METHODS: We prospectively collected data from all TELD performed by five neurosurgeons at five different medical centers between February and October of 2022. The study population was dichotomized by anesthesia scheme, creating CS and GA cohorts. This study's primary outcomes were the Oswetry Disability Index (ODI) and the Visual Analog Scale (VAS) for back and leg pain, assessed preoperatively and at 2-week follow-up. RESULTS: A total of 52 patients underwent TELD for symptomatic lumbar disk herniation. Twenty-three patients received conscious sedation with local anesthesia, and 29 patients were operated on under general anesthesia. Patients who received CS were significantly older (60.0 vs. 46.7, p < 0.001) and had lower BMI (28.2 vs. 33.4, p = 0.005) than patients under GA. No intraoperative or anesthetic complications occurred in the CS and GA cohorts. Improvement at 2-week follow-up in ODI, VAS-back, and VAS-leg was greater in patients receiving CS relative to patients under GA, but these differences were not statistically significant. CONCLUSION: In our multicenter prospective analysis of 52 patients undergoing TELD, we found that patients receiving CS were significantly older and had significantly lower BMI compared to patients under GA. On subgroup analysis, no statistically significant differences were found in the improvement of PROMs between patients in the CS and GA group.

Learning curve for endoscopic posterior cervical foraminotomy.

PURPOSE: While anterior cervical discectomy and fusion as well as cervical disk arthroplasty are gold standard treatments for the surgical treatment of cervical radiculopathy, posterior endoscopic cervical foraminotomy (PECF) as a substitute procedure is gaining popularity. To date, studies investigating the number of surgeries needed to achieve proficiency in this procedure are lacking. The purpose of the study is to examine the learning curve for PECF. METHODS: The learning curve in operative time for two fellowship-trained spine surgeons at independent institutions was retrospectively assessed for 90 uniportal PECF procedures (PBD: n = 26, CPH: n = 64) performed from 2015 to 2022. Operative time was assessed across consecutive cases using a nonparametric monotone regression, and a plateau in operative time was used as a proxy to define the learning curve. Secondary outcomes assessing achievement of endoscopic prowess before and after the initial learning curve included number of fluoroscopy images, visual analog scale (VAS) for neck and arm, Neck Disability Index (NDI), and the need for reoperation. RESULTS: There was no significant difference in operative time between surgeons (p = 0.420). The start of a plateau for Surgeon 1 occurred at 9 cases and 111.6 min. The start of a plateau for Surgeon 2 occurred at 29 cases and 114.7 min. A second plateau for Surgeon 2 occurred at 49 cases and 91.8 min. Fluoroscopy use did not significantly change before and after surmounting the learning curve. The majority of patients achieved minimally clinically important differences in VAS and NDI after PECF, but postoperative VAS and NDI did not significantly differ before and after achieving the learning curve. There were no significant differences in revisions or postoperative cervical injections before and after reaching a steady state in the learning curve. CONCLUSION: PECF is an advanced endoscopic technique with an initial improvement in operative time that occurred after as few as 8 cases to as many as 28 cases in this series. A second learning curve may occur with additional cases. Patient-reported outcomes improve following surgery, and these outcomes are independent of the surgeon's position on the learning curve. Fluoroscopy use does not change significantly along the learning curve. PECF is a safe and effective technique that current and future spine surgeons should consider as part of their armamentarium.

Accuracy of various fluoroscopic landmarks for determination of midline implant placement within the cervical disc space.

PURPOSE: The traditional teaching has been that proper function of a cervical disc replacement is dependent upon appropriate placement, which includes centering the device in the coronal plane. The purpose of this study was to identify the most reliable anatomical landmark for determining midline placement of an implant within the cervical disc space under fluoroscopy. METHODS: Digital fluoroscopy images were taken for each cervical level at 0 °, 2.5 °, 5 °, 7.5 °, 10 °, and 15 ° from the mid-axis by rotating the C-arm beam of six cadavers. Thin-slice CT scanning of the same levels was subsequently performed. Three independent reviewers measured the distance between anatomic structures: (a) tip of the right uncinate; (b) medial border of the right pedicle; and (c) center of the spinous processes for different x-ray angles across cervical levels C3-7. RESULTS: Both the uncinate and pedicle demonstrated superior overall accuracy to that of the spinous process (p ≤ 0.02) at all angles except at 0 ° for the pedicle where the difference was not statistically significant. Overall (pooled C3-7), the accuracy of the uncinate did not differ significantly from that of the pedicle at any fluoroscopic angle. The center of the spinous process measurement was particularly sensitive to deviations from the perfect anteroposterior fluoroscopy image. CONCLUSIONS: The results of this investigation suggest that the tip of the uncinate and the medial border of the pedicle are more accurate measures of midline in the cervical spine than the center of the spinous process and are less susceptible to inadvertent off-axis imaging.

Assessing the cone of economy in patients with spinal disease using only a force plate: an observational retrospective cohort study.

STUDY DESIGN: This is a retrospective cohort with multiple regression modeling. OBJECTIVE: The aim is to develop a new method for estimating cone of economy (CoE) using a force plate rather than traditional motion capture. BACKGROUND: Currently, most spinal deformity surgeons rely on static radiographic parameters for alignment, balance, and outcomes data alongside patient-reported outcome measures. The CoE, the stable region of upright posture, can be objectively measured to determine the efficiency and balance of the spine. Motion capture technology is currently used to collect data to calculate CoE, but this requires expensive and complex equipment, which is a barrier to widespread adoption and clinical use of CoE measurements. Force plates, which measure pressure, are less expensive and can be used in a clinical setting. METHODS: Motion capture and a force plate were used to quantify the CoE of 473 subjects (423 spinal surgical candidates; 50 healthy controls; 271 females; age: 58.60 ± 15.27; height: 1.69 ± 0.13; weight: 81.07 ± 20.91), and a linear multiple regression model was used to predict CoE using force plate data in a human motion laboratory setting. Patients were required to stand erect with feet together and eyes open in their self-perceived balanced and natural position for a full minute while measures of sway and center of pressure (CoP) were recorded. RESULTS: The CoP variable regression model successfully predicted CoE measurements. The variables that were used to predict vertical CoE were CoP coronal sway, CoP sagittal sway, and CoP total sway in several combinations. The coefficient of determination for the head total sway model indicated a 87.0% correlation (F(3,469) = 1044.14, p < 0.001). The coefficient of determination for the head sagittal sway model indicated a 69.2% correlation (F(3,469) = 351.70, p < 0.001). The coefficient of determination for the head coronal sway model indicated a 85.2% correlation (F(3,469) = 899.27, p < 0001). CONCLUSION: Cone of economy was estimated from force plate data using center of pressure with high correlation without the use of motion capture in healthy controls and a variety of spine patients. This could lower the entry burden for measurement of the CoE in patients, enabling widespread use. This would provide surgeons objective global balance data, along with Haddas' CoE classification system, that could assist with surgical decision-making and facilitate objective monitoring surgical outcomes.

Will Medicare Readmission Penalties Motivate Hospitals to Reduce Arthroplasty Readmissions?

BACKGROUND: The Centers for Medicare & Medicaid Services (CMS) recently imposed penalties against hospitals with above-average 30-day readmission rates following total joint arthroplasty (TJA). Hospitals must decide whether investments in readmission prevention are worthwhile. This study examines the financial incentives associated with unplanned readmissions before and after invocation of these penalties. METHODS: Financial data were reviewed for 2028 consecutive primary TJAs performed on Medicare beneficiaries over a 2-year period at an urban academic health system. Readmission penalties were estimated in accordance with CMS policies. RESULTS: Unplanned readmissions generated a $4416 median contribution margin. The initial hospitalizations (when the TJA was performed) were financially unfavorable for patients subsequently readmitted relative to those not readmitted due to increased costs of care (P = .002), but these costs were more than outweighed by the increased reimbursement earned during the readmission (P < .001), ultimately making readmitted patients financially preferable (P < .001). Going forward, penalties will be levied for risk-adjusted readmission rates above the national rate of 4.8%. For the institution under review, the penalty per readmission outweighs the financial gains earned through readmission by $12,184, resulting in a net loss from readmissions if the rate exceeds 6.5%. It will be financially optimal to maintain a readmission rate (after risk adjustment) equal to the national average but exceeding that rate will be $7768 more expensive per readmission than undershooting that target. CONCLUSION: If our results are generalizable, unplanned Medicare readmissions have traditionally been financially beneficial, but CMS penalties outweigh this benefit. Thus, penalties should incentivize institutions to maintain below-average arthroplasty readmissions rates.

What Financial Incentives Will Be Created by Medicare Bundled Payments for Total Hip Arthroplasty?

BACKGROUND: Bundled payments are gaining popularity in arthroplasty as a tactic for encouraging providers and hospitals to work together to reduce costs. However, this payment model could potentially motivate providers to avoid unprofitable patients, limiting their access to care. Rigorous risk adjustment can prevent this adverse effect, but most current bundling models use limited, if any, risk-adjustment techniques. This study aims to identify and quantify the financial incentives that are likely to develop with total hip arthroplasty (THA) bundled payments that are not accompanied by comprehensive risk stratification. METHODS: Financial data were collected for all Medicare-eligible patients (age 65+) undergoing primary unilateral THA at an academic center over a 2-year period (n = 553). Bundles were considered to include operative hospitalizations and unplanned readmissions. Multivariate regression was performed to assess the impact of clinical and demographic factors on the variable cost of THA episodes, including unplanned readmissions. (Variable costs reflect the financial incentives that will emerge under bundled payments). RESULTS: Increased costs were associated with advanced age (P < .001), elevated body mass index (BMI; P = .005), surgery performed for hip fracture (P < .001), higher American Society of Anaesthesiologists (ASA) Physical Classification System grades (P < .001), and MCCs (Medicare modifier for major complications; P < .001). Regression coefficients were $155/y, $107/BMI point, $2775 for fracture cases, $2137/ASA grade, and $4892 for major complications. No association was found between costs and gender or race. CONCLUSION: If generalizable, our results suggest that Centers for Medicare and Medicaid Services bundled payments encompassing acute inpatient care should be adjusted upward by the aforementioned amounts (regression coefficients above) for advanced age, increasing BMI, cases performed for fractures, elevated ASA grade, and major complications (as defined by Medicare MCC modifiers). Furthermore, these figures likely underestimate costs in many bundling models which incorporate larger proportions of postdischarge care. Failure to adjust for factors affecting costs may create barriers to care for specific patient populations.

What Incentives Are Created by Medicare Payments for Total Hip Arthroplasty?

BACKGROUND: Differences in profitability and contribution margin (CM) between various patient populations may make certain patients particularly attractive (or unattractive) to providers. This study seeks to identify patient characteristics associated with increased profit and CM among Medicare patients undergoing total hip arthroplasty (THA). METHODS: The expected Medicare reimbursement for consecutive patients of Medicare-eligible age (65+ years) undergoing primary unilateral elective THA (n = 498) was calculated in accordance with Center for Medicare and Medicaid Services policy. Costs were derived from the hospital's cost accounting system. Profit and CM were calculated for each patient as reimbursement less total and variable costs, respectively. Patients were compared based on clinical and demographic factors by univariate and multivariate analyses. RESULTS: Medicare patients undergoing THA generated negative average profits but substantial positive CMs. Lower profit and CM were associated with higher American Society of Anesthesiologists Physical Status Classification (P < .01, P = .03), older age (P < .01), and longer length of stay (P < .01, P = .03). No association was found with gender, body mass index, or race. CONCLUSION: If our results are generalizable, Medicare patients requiring THA are currently financially attractive, but institutions have a long-term incentive to shift resources to more profitable patients and service lines, which may eventually restrict access to care for this population. THA providers have a financial incentive to favor Medicare patients with younger age, lower American Society of Anesthesiologists Physical Status Classification, and those who can be expected to require relatively short admissions. The Center for Medicare and Medicaid Services must strive to accurately match reimbursement rates to provider costs to avoid inequitable payments to providers and financial incentives discouraging treatment of high-risk patients or other patient subpopulations.

What are the economic consequences of unplanned readmissions after TKA?

BACKGROUND: In 2009, the Center for Medicare & Medicaid Services (CMS) began penalizing hospitals with high rates of 30-day readmissions after hospitalizations for certain conditions. This policy will expand to include TKA in 2015. QUESTIONS/PURPOSES: What are the median profits and contribution margins of: (1) Medicare-reimbursed TKA, (2) 30-day TKA readmission, and (3) entire episode of care for readmitted TKA patients within 30 days compared to nonreadmitted patients? (4) Under new CMS guidelines, what financial penalty will the authors' institution face if its arthroplasty readmission rate exceeds the national average? METHODS: A retrospective review of 3218 primary TKAs performed during 2 years at a large urban academic hospital network was conducted using administrative and financial data. RESULTS: The median profit and contribution margins, respectively, were as follows: TKA episode, USD 5209 and USD 11,726; 30-day readmission, USD 608 and USD 3814; TKA visit with readmission, USD 2855 and USD 13,901; TKA visit without readmission, USD 5300 and USD 11,652. Readmission penalties could reach USD 6.21 million per year for the authors' institution. DISCUSSION: If our results are generalizable, unplanned TKA readmissions lead to diminished total profit. Although associated with a positive contribution margin, this is likely to be a short-term phenomenon as the new CMS policy will result in readmissions coming at a steep cost to referral centers.

Are there identifiable risk factors and causes associated with unplanned readmissions following total knee arthroplasty?

We conducted a retrospective review of 3218 primary total knee arthroplasties (TKA) performed over two years at an urban academic hospital network using clinical and administrative data. Increased length of stay (LOS) was associated with readmission (P < 0.001). Readmission was not associated with age (P = 0.100), gender (P = 0.608), body mass index (P = 0.329), or staged bilateral procedures (P = 0.420). The most common readmitting diagnoses were post-operative infection (22.5%), hematoma (10.1%), pulmonary embolus (7.9%) and deep vein thrombosis (5.6%). Of readmissions, 53.9% were for surgical reasons and 46.1% were for medical reasons. Certain interventions described in previous literature may be more successful in minimizing unplanned readmissions by focusing on patients with extended LOS, elevated infection risk and low socioeconomic status.

Minimally Invasive Revision of Luque Plate Instrumentation: A Case Report.

Extension of existing spinal fusions may necessitate the removal of or linkage to prior constructs. Knowledge of previously placed instrumentation is critical to success in these revision scenarios. The Luque spinal instrumentation system, developed in the late 1980s, is a legacy pedicle screw and plate system that may be encountered during revision operations today. A 67-year-old male with a remote history of L4-S1 fusion with Luque instrumentation presented with bilateral lower extremity neurogenic claudication due to adjacent segment disease at L3-4. Decompression and extension of fusion to the L3-4 level were performed using minimally invasive techniques. Of note, posterior instrumentation was extended by removing prior L4 pedicle screws with a 7 mm female hexagonal driver through tubular retractors, leaving the Luque plates in place, placing modern pedicle screws at L4 (through the plates) and L3, and linking these with standard rods. The surgery and post-operative course were uncomplicated, and the patient experienced complete resolution of his pre-operative claudication symptoms. Extension of prior Luque plate instrumented fusion can be accomplished minimally invasively without removing the plates themselves, resulting in greater operative efficiency and less surgical morbidity.

Endoscopic Spine Surgery on Instagram: Analysis of Content and Engagement.

Introduction Social media platforms have changed the way society communicates and collaborates. Prior research in healthcare discusses how social media can empower patients, dispel health-related misinformation, and help maintain a patient-centered practice. The goal of this study was to evaluate the use of #endoscopicspinesurgery on Instagram and create a blueprint for creating engaging posts on the social media platform. Methodology Public Instagram posts (n = 171) that utilized #endoscopicspinesurgery were collected over three months in 2022. Each post was assessed for photo and caption content, likes, comments, number of followers, and hashtag information. Engagement rates were calculated for each post to assess the active interaction of post characteristics and content. Results The majority of posts were published by medical professionals (72/171, 42.1%) and industry-related user accounts (55/171, 32.2%). Content related to training, conferences, and the operating room garnered the highest average engagement. Post characteristics (number of hashtags and number of post photos) were significantly associated with engagement. Conclusions Results highlighted general trends in creating engaging social media posts, such as using hashtags intentionally to increase searchability and visibility, having higher numbers of photos in a post and using high-quality photos, and understanding the dynamic social media algorithms that may affect post viewership. When structuring social media posts, users should be aware of the audience they want to attract and construct their content accordingly.

Unplanned hip arthroplasty imposes clinical and cost burdens on treating institutions.

BACKGROUND: Emergent surgery has been shown to be a risk factor for perioperative complications. Studies suggest that patient morbidity is greater with an unplanned hip arthroplasty, although it is controversial whether unplanned procedures also result in higher patient mortality. The financial impact of these procedures is not fully understood, as the costs of unplanned primary hip arthroplasties have not been studied previously. QUESTIONS/PURPOSES: We asked: (1) What are the institutional costs associated with unplanned hip arthroplasties (primary THA, hemiarthroplasty, revision arthroplasty, including treatment of periprosthetic fractures, dislocations, and infections)? (2) Does timing of surgery (urgent/unplanned versus elective) influence perioperative outcomes such as mortality, length of stay, or need for advanced care? (3) What diagnoses are associated with unplanned surgery and are treated urgently most often? (4) Do demographics and insurance status differ between admission types (unplanned versus elective hip arthroplasty)? METHODS: We prospectively followed all 419 patients who were admitted to our Level I trauma center in 2011 for procedures including primary THA, hemiarthroplasty, and revision arthroplasty, including the treatment of periprosthetic fractures, dislocations, and infections. Fifty-seven patients who were treated urgently on an unplanned basis were compared with 362 patients who were treated electively. Demographics, admission diagnoses, complications, and costs were recorded and analyzed statistically. RESULTS: Median total costs were 24% greater for patients admitted for unplanned hip arthroplasties (USD 18,206 [USD 15,261-27,491] versus USD 14,644 [USD 13,511-16,309]; p < 0.0001) for patients admitted for elective arthroplasties. Patients with unplanned admissions had a 67% longer median hospital stay (5 days [range, 4-9 days] versus 3 days [range, 3-4 days]; p < 0.0001) for patients with elective admissions. Mortality rates were equivalent between groups (p = 1.0). Femoral fracture (p < 0.0001), periprosthetic fracture (p = 0.01), prosthetic infection (p = 0.005), and prosthetic dislocation (p < 0.0001) were observed at higher rates in the patients with unplanned admissions. These patients were older (p = 0.04), less likely to have commercial insurance (p < 0.0001), more likely to be transferred from another institution (p < 0.0001), and more likely to undergo a revision procedure (p < 0.0001). CONCLUSIONS: Unplanned arthroplasty and urgent surgery are associated with increased financial and clinical burdens, which must be accounted for when considering bundled quality and reimbursement measures for these procedures.

Transfer of hip arthroplasty patients leads to increased cost and resource utilization in the receiving hospital.

Factors other than complexity of care often drive the transfer of orthopedic patients to tertiary centers. We sought to compare the demographics, diagnoses, insurance data, peri-operative outcomes and institutional costs of total hip arthroplasty patients transferred from outside facilities with those of patients derived from our clinics. We analyzed 419 consecutive patients as part of a prospective risk study. Transferred patients were older (P=0.01), less likely to have private insurance (P<0.0001), and more likely to be admitted on weekends (P=0.04). Both dislocation and fracture were more prevalent in transferred patients (P=0.04; P=0.003). Across all key metrics - including length of stay, mortality scoring, peri-operative complications, and direct and total costs - transferred patients more significantly strained the resources of our arthroplasty center.

Risk factors, causes, and the economic implications of unplanned readmissions following total hip arthroplasty.

In order to identify risk factors for readmissions following total hip arthroplasty (THA) and the causes and financial implications of such readmissions, we analyzed clinical and administrative data on 1583 consecutive primary THAs performed at a single institution. The 30-day readmission rate was 6.51%. Increased age, length of stay, and body mass index were associated with significantly higher readmission rates. The most common re-admitting diagnoses were deep infection, pain, and hematoma. Average profit was lower for episodes of care with readmissions ($1548 vs. $2872, P=0.028). If Medicare stops reimbursing for THA readmissions, the institution under review would sustain an average net loss of $11,494 for episodes of care with readmissions and would need to maintain readmission rates below 23.6% in order to remain profitable.

Cement technique for reducing post-operative bursitis after trochanteric fixation.

Post-operative trochanteric bursitis is a known complication secondary to the surgical approach in total hip arthroplasty. This phenomenon may be partially attributable to repetitive microtrauma generated when soft tissues rub against implanted hardware. Significant rates of post-operative trochanteric bursitis have been observed following procedures in which a trochanteric fixation device, such as a bolt-washer mechanism or a cable-grip/claw system, is used to secure the trochanteric fragment after trochanteric osteotomy. We present a simple technique for use with a bolt-washer system or grip plate in which trochanteric components are covered in bone wax followed by a layer of cement to decrease friction and to diminish the risk of post-operative bursitis.

Device profile of the FlareHawk interbody fusion system, an endplate-conforming multi-planar expandable lumbar interbody fusion cage.

INTRODUCTION: The FlareHawk Interbody Fusion System is a family of lumbar interbody fusion devices (IBFDs) that include FlareHawk7, FlareHawk9, FlareHawk11, TiHawk7, TiHawk9, and TiHawk11. These IBFDs offer a new line of multi-planar expandable interbody devices designed to provide mechanical stability, promote arthrodesis, and allow for restoration of disc height and lordosis through a minimal insertion profile during standard open and minimally invasive posterior lumbar fusion procedures. The two-piece interbody cage design consists of a PEEK outer shell that expands in width, height, and lordosis with the insertion of a titanium shim. Once expanded, the open architecture design allows for ample graft delivery into the disc space. AREAS COVERED: The design and unique features of the FlareHawk family of expandable fusion cages are described. The indications for their use are discussed. Early clinical and radiographic outcome studies using the FlareHawk Interbody Fusion System are reviewed, and properties of competitor products are outlined. EXPERT OPINION: The FlareHawk multi-planar expandable interbody fusion cage is unique amongst the many lumbar fusion cages currently on the market. The multi-planar expansion, open architecture, and adaptive geometry set it apart from its competitors.

Collagen Matrix Inlay Graft for Management of Incidental Durotomy During Full-Endoscopic Lumbar Spine Surgery: Technique and Case Series.

BACKGROUND: Endoscopic spine surgery (ESS) has a reduced rate of incidental durotomy (ID) compared with open spine surgery. However, there are unique challenges regarding the management of ID in ESS due to the single, deep, narrow working corridor and aqueous environment. Here, we present a collagen matrix inlay graft technique for the management of ID encountered during ESS. METHODS: Three patients were identified via medical record review of full ESS where an intraoperative ID was encountered. These were all addressed endoscopically. All surgeries were performed by a single surgeon in the years 2019 to 2023. Patient, operative, and postoperative details, including patient-reported outcomes, were recorded. Briefly, the collagen matrix inlay graft technique included introducing a segment of collagen matrix into the surgical field and manipulating the collagen matrix so that it passed through the durotomy and resided within the dura, plugging the hole. RESULTS: Three IDs were identified out of a total of 295 eligible cases (1.02%). The IDs measured 2 to 2.5 mm in length. For these 3 patients, the duration of hospital stay ranged from 172 to 1,068 minutes. No patients exhibited signs or symptoms of cerebrospinal fluid leak at any postoperative timepoint. At the 6-week postoperative visit, all patients had achieved the minimum clinically important difference in Oswestry Disability Index, and all patients with available visual analog scale scores for leg and low back pain had achieved the cutoff for the minimum clinically important difference. CONCLUSIONS: We presented 3 cases of ID during uniportal full ESS who were repaired using a collagen matrix inlay technique. Prolonged bed rest was avoided, and all patients achieved excellent clinical outcomes without further complication. This technique may also be appropriate for other minimally invasive spine surgery techniques. CLINICAL RELEVANCE: ID is a common and undesirable complication of degenerative lumbar spine surgery. Endoscopic ID repair techniques provide an option to avoid conversion to open or tubular surgery for the management of ID.

Cervical Disk Arthroplasty and Range of Motion at 7 Years: Impact on Adjacent Level Degeneration.

STUDY DESIGN: Secondary analysis of data collected in a prospective, randomized, noninferiority Food and Drug Administration (FDA) Investigational Device Exemption (IDE) clinical trial. OBJECTIVE: The objective of this study was to evaluate the impact of range of motion (ROM) following single-level cervical disk arthroplasty (CDA) on the development of radiographic adjacent level degeneration (ALD). SUMMARY OF BACKGROUND DATA: The rationale for CDA is that maintenance of index-level ROM will decrease adjacent level stresses and ultimately reduce the development of ALD compared with anterior cervical discectomy and fusion. However, little information is available on the impact of hypermobility on the development of ALD after CDA. MATERIALS AND METHODS: Radiographic assessments were evaluated for index-level flexion-extension ROM and ALD. Continuous data was assessed using 1-way analysis of variance. The relationship between ALD progression and ROM was evaluated using χ 2 tests. The α was set at 0.05. RESULTS: More ALD progression was observed after anterior cervical discectomy and fusion than CDA ( P =0.002 at the superior and P =0.049 at the inferior level). Furthermore, there was an association between ALD progression and ROM ( P =0.014 at the superior level and P =0.050 at the inferior level) where patients with mid-ROM after CDA experienced the lowest frequency of ALD progression at the superior and inferior levels. Patients with the lowest and highest ROM after CDA experienced a greater increase in ALD score at the inferior level ( P =0.046). Sex and age were associated with ROM groups ( P =0.001 and 0.023, respectively). CONCLUSIONS: While maintenance of index-level ROM is protective after CDA, patients with the highest ROM after CDA have similar rates of ALD progression to the lowest ROM and greater increases in ALD compared with mid-ROM after CDA. High ROM after CDA may contribute to ALD progression.

Preservation of Motion in Spine Surgery.

The number of spinal procedures and spinal fusions continues to grow. Although fusion procedures have a high success rate, they have inherent risks such as pseudarthrosis and adjacent segment disease. New innovations in spine techniques have sought to eliminate these complications by preserving motion in the spinal column. Several techniques and devices have been developed in the cervical and lumbar spine including cervical laminoplasty, cervical disk ADA, posterior lumbar motion preservation devices, and lumbar disk ADA. In this review, advantages and disadvantages of each technique will be discussed.

Development of an Endoscopic Spine Surgery Program: Overview and Basic Considerations for Implementation.

Endoscopic spine surgery (ESS) is an innovative technique allowing for minimally invasive, direct visualization of spinal abnormalities. The growth of ESS in the United States has been stunted by high start-up costs, low reimbursement rates, and the steep learning curve associated with mastering endoscopic techniques. Hergrae, we describe the current state and future direction of ESS and provide key action items for ESS program implementation.