Safety and Feasibility of Steroid-Eluting Stent as a Bolster in Endoscopic Anterior Skull Base Reconstruction.

BACKGROUND: With a rising incidence of cerebrospinal fluid (CSF) leaks, endoscopic endonasal CSF leak repair is increasingly performed. Current approaches utilize a variety of materials including free mucosal grafts and vascularized flaps, but post-op leaks continue to be reported. Steroid-eluting bioabsorbable stents (SES) are used during functional endoscopic sinus surgery for chronic rhinosinusitis to reduce inflammation and scarring while maintaining patency of sinus ostia. OBJECTIVE: The aim of this study is to assess the feasibility of SES as a graft/flap bolster for endoscopic endonasal CSF leak repair. METHODS: This is a retrospective review of patients undergoing endoscopic endonasal CSF leak repair with SES placed as part of the bolster technique at a tertiary care center between January 2019 and May 2022. Age, sex, BMI, comorbid idiopathic intracranial hypertension, pathology, location of CSF leak, intraoperative CSF leak flow, reconstruction type, and presence of post-op CSF leak were recorded. RESULTS: Twelve patients (mean age 52, median BMI 30.9, 58% female) had SES placement as part of the bolster technique. The most common pathology was meningoencephalocele (75%). Reconstruction was performed with either a free mucosal graft (6), or a flap (6). No post-op CSF leaks occurred at a reconstruction site with a stent, and no known complications were reported. All sinusotomies were patent at the last follow-up visit. CONCLUSIONS: SES placement as an adjunct to graft and/or flap bolster appears to be safe and feasible during anterior skull base reconstruction and CSF leak repair providing longer term structural support and preserving sinus drainage patency.

Preparation and Characterization of Mono- and Biphasic Ca1-xAgxHPO4·nH2O Compounds for Biomedical Applications.

This study aimed to explore the effects of the full-scale replacement (up to 100%) of Ca2+ ions with Ag1+ ions in the structure of brushite (CaHPO4·2H2O). This substitution has potential benefits for producing monophasic and biphasic Ca1-xAgxHPO4·nH2O compounds. To prepare the starting solutions, (NH4)2HPO4, Ca(NO3)2·4H2O, and AgNO3 at different concentrations were used. The results showed that when the Ag/Ca molar ratio was below 0.25, partial substitution of Ca with Ag reduced the size of the unit cell of brushite. As the Ag/Ca molar ratio increased to 4, a compound with both monoclinic CaHPO4·2H2O and cubic nanostructured Ag3PO4 phases formed. There was a nearly linear relationship between the Ag ion ratio in the starting solutions and the wt% precipitation of the Ag3PO4 phase in the resulting compound. Moreover, when the Ag/Ca molar ratio exceeded 4, a single-phase Ag3PO4 compound formed. Hence, adjusting the Ag/Ca ratio in the starting solution allows the production of biomaterials with customized properties. In summary, this study introduces a novel synthesis method for the mono- and biphasic Ca1-xAgxHPO4·nH2O compounds brushite and silver phosphate. The preparation of these phases in a one-pot synthesis with controlled phase composition resulted in the enhancement of existing bone cement formulations by allowing better mixing of the starting ingredients.

Polycomb repressive complex 2 regulates basal cell fate during adult olfactory neurogenesis.

Adult neurogenesis occurs in the mammalian olfactory epithelium to maintain populations of neurons that are vulnerable to injury yet essential for olfaction. Multipotent olfactory basal stem cells are activated by damage, although mechanisms regulating lineage decisions are not understood. Using mouse lesion models, we focused on defining the role of Polycomb repressive complexes (PRCs) in olfactory neurogenesis. PRC2 has a well-established role in developing tissues, orchestrating transcriptional programs via chromatin modification. PRC2 proteins are expressed in olfactory globose basal cells (GBCs) and nascent neurons. Conditional PRC2 loss perturbs lesion-induced neuron production, accompanied by altered histone modifications and misexpression of lineage-specific transcription factors in GBCs. De-repression of Sox9 in PRC2-mutant GBCs is accompanied by increased Bowman's gland production, defining an unrecognized role for PRC2 in regulating gland versus neuron cell fate. Our findings support a model for PRC2-dependent mechanisms promoting sensory neuronal differentiation in an adult neurogenic niche.

Nasal Cavity Squamous Cell Carcinoma: Factors Associated With Treatment Outcomes and Potential Organ Preservation.

BACKGROUND: Squamous cell carcinoma of the nasal cavity (NCSCC) is a rare, challenging malignancy. Surgical resection of this tumor can cause significant facial deformity, and indications for adjuvant or organ preservation therapies are not well-described. OBJECTIVE: To examine the impact of treatment regimen on survival outcomes in NCSCC and to compare surgical to non-surgical based therapies. METHODS: The National Cancer Database was queried for NCSCC from 2004 to 2014. Patient demographics, tumor characteristics, and treatment regimen were compared for the entire cohort. Multivariable Cox proportional hazards regression was performed for statistical analysis of treatment regimen and surgical margins on overall survival (OS) for early and late-stage disease. RESULTS: A total of 1883 NCSCC patients were identified. The OS for the cohort was 83 months, and median age at diagnosis was 65 years. NCSCC patients who underwent surgery followed by adjuvant radiation therapy (RT) had a better OS compared to definitive RT (HR: 0.58, P < .001). In early stage NCSCC (T1/T2, N0), there was no significant difference in OS between patients treated with surgery only or surgery with adjuvant RT compared to definitive RT. In advanced stage NCSCC, surgery with adjuvant RT had a better OS compared to definitive chemoradiation. Having positive margins was shown to predict a worse OS when compared to negative margins in surgical patients despite adjuvant RT or chemoradiation. CONCLUSIONS: NCSCC appears to be best treated with surgery followed by adjuvant RT in advanced-stage disease whereas in early-stage disease, surgery does not improve OS compared to definitive RT.

Endoscopic Sinus Surgery in Older Patients With Significant Medical Comorbidities.

BACKGROUND: Endoscopic sinus surgery (ESS) offers excellent outcomes for patients with chronic rhinosinusitis (CRS) in the general population. It is unclear whether older patients with significant medical comorbidities experience similar benefits. OBJECTIVE: The purpose of this study is to evaluate whether increasing medical comorbidity is associated with worse sinonasal quality of life outcomes after ESS in older patients. METHODS: This is a retrospective study of CRS patients 55 years or older who underwent elective ESS at an academic institution from July 2017 to June 2019. 22-Item Sino-Nasal Outcomes Test (SNOT-22) scores were gathered at baseline as well as at 3 and 6 months following surgery. Data on demographics, medical comorbidities, preoperative Lund-Mackay (LM) scores, and postoperative complications were extracted from the medical record. The Charlson Comorbidity Index (CCI) was calculated for each patient. Multivariate linear regression was used to evaluate a potential association between CCI and change in SNOT-22 scores at 3 months postoperatively. RESULTS: A total of 205 patients met inclusion criteria with a mean (SD) CCI score of 2 (2.4) and a CCI score range of 0 to 11. The mean (SD) LM score was 8 (5.3). Rates of asthma and nasal polyposis were 28.3% and 36.6%, respectively. The mean (SD) improvement in SNOT-22 scores at 3 and 6 months compared to baseline was 17.9 (19.7) and 20.9 (18.1) points, respectively. After adjusting for covariates, there was no significant association between CCI and change in SNOT-22 scores. CONCLUSION: Greater medical comorbidity is not associated with worse SNOT-22 outcomes postoperatively, although future studies are needed to determine if comorbidities are associated with higher complication rates. A multidisciplinary approach to perioperative care is critical in maintaining the safety and efficacy of ESS in this patient population.

Aging-related olfactory loss is associated with olfactory stem cell transcriptional alterations in humans.

BACKGROUNDPresbyosmia, or aging-related olfactory loss, occurs in a majority of humans over age 65 years, yet remains poorly understood, with no specific treatment options. The olfactory epithelium (OE) is the peripheral organ for olfaction and is subject to acquired damage, suggesting a likely site of pathology in aging. Adult stem cells reconstitute the neuroepithelium in response to cell loss under normal conditions. In aged OE, patches of respiratory-like metaplasia have been observed histologically, consistent with a failure in normal neuroepithelial homeostasis.MethodsAccordingly, we have focused on identifying cellular and molecular changes in presbyosmic OE. The study combined psychophysical testing with olfactory mucosa biopsy analysis, single-cell RNA-Sequencing (scRNA-Seq), and culture studies.ResultsWe identified evidence for inflammation-associated changes in the OE stem cells of presbyosmic patients. The presbyosmic basal stem cells exhibited increased expression of genes involved in response to cytokines or stress or the regulation of proliferation and differentiation. Using a culture model, we found that cytokine exposure drove increased TP63, a transcription factor acting to prevent OE stem cell differentiation.ConclusionsOur data suggest aging-related inflammatory changes in OE stem cells may contribute to presbyosmia via the disruption of normal epithelial homeostasis. OE stem cells may represent a therapeutic target for restoration of olfaction.FundingNIH grants DC018371, NS121067, DC016224; Office of Physician-Scientist Development, Burroughs-Wellcome Fund Research Fellowship for Medical Students Award, Duke University School of Medicine.

A Retrospective Study of Lymph Node Yield in Lateral Neck Dissection for Papillary Thyroid Carcinoma.

OBJECTIVE: Lateral neck dissection (LND) is important in managing papillary thyroid carcinomas (PTCs). This study aimed to evaluate the relationship between lymph node yield (LNY) for LND and patient outcomes, specifically postoperative serum thyroglobulin levels (sTG) and radioiodine uptake on thyroid scan, and to estimate a threshold LNY to signify adequate LND. METHODS: Patients diagnosed with PTC who underwent LND from 2006 to 2015 at a single institution were included. Linear regression with restricted cubic splines was used to characterize the association of LNY with outcomes. Outcomes were log-transformed to achieve a more symmetric distribution prior to regression. For nonlinear associations, a Monte Carlo Markov Chain procedure was used to estimate a threshold LNY associated with postoperative outcome. This threshold was then used to define high LNY versus low LNY in the subsequent analyses. RESULTS: In total, 107 adult patients were included. There was a significant relationship between LNY and postoperative sTG level (P = .004), but not radioiodine uptake (P = .64). An LNY of 42.96 was identified, which was associated with the maximum change in sTG level. No association was found between LNY groups (LNY ≥ 43 vs < 43) and radioiodine uptake, risk of complication, or longer operative times (all P > .05). High LNY was associated with a decrease in log(sTG) (estimate = -1.855, P = .03), indicating that adequacy of LND is associated with an 84.4% decrease in sTG. CONCLUSION: These results suggest an association between LNY and postoperative sTG level, with an estimated threshold of 43 nodes. This has implications for adequate therapeutic LND; additional work is needed to validate thresholds for clinical practice.

Endoscopic Sinus Surgery for Cystic Fibrosis: Variables Influencing Sinonasal and Pulmonary Outcomes.

BACKGROUND: Endoscopic sinus surgery is a well-established treatment for chronic rhinosinusitis in patients with cystic fibrosis, though its benefits seem to be limited to improving sinonasal symptoms rather than affecting lung function. OBJECTIVE: This study aims to identify clinical and demographic factors that may influence sinonasal and pulmonary outcomes after surgery. METHODS: This is a six-year retrospective analysis of adult cystic fibrosis patients who underwent endoscopic sinus surgery at a tertiary care center. 22-Item Sino-Nasal Outcomes Test scores and mean forced expiratory volume data at baseline and three to six months after surgery were analyzed using t-test and stepwise regression with the following covariates: age, gender, lung transplant, revision surgery, and pseudomonas on sinus culture. RESULTS: 119 surgeries were performed on 88 patients, with 69% on patients with transplant. The overall mean (Standard Deviation) improvement in 22-Item Sino-Nasal Outcomes Test score was 9.42 (18.15) for the entire cohort (P < .001). Pseudomonas on culture was associated with less improvement in sinonasal scores (P = .002). There was no significant change in forced expiratory volume after surgery (P = .94). Revision surgery (P = .004) and older age (P = .007) were associated with less favorable change of pulmonary function on stepwise regression (P = .002). There was no correlation between change in sinonasal scores and pulmonary function. CONCLUSION: Although surgery was associated with a clinically and statistically significant improvement in sinonasal scores in cystic fibrosis patients, patients with pseudomonas may experience less benefit. Revision surgery and older age may be associated with less favorable pulmonary outcomes. Awareness of such variables may help when deciding which cystic fibrosis patients should undergo surgery.

Mesenteric Malperfusion Syndromes in Type A Aortic Dissection: Current Management Strategies.

Acute type A aortic dissection is a surgical emergency associated with high mortality and morbidity. When complicated with mesenteric malperfusion, its management carries a very high mortality. Many innovations in the field of vascular and cardiothoracic surgery in the last two decades have been tried in the continuous efforts to improve on the surgical outcomes. Although some reports have documented better mortality rates with reperfusion-first strategies, there is still room for improvement in the absence of a general consensus on its management.

Analysis of Self- and 360-Evaluation Scores of the Professionalism Intelligence Model Within an Academic Otolaryngology-Head and Neck Surgery Department.

PURPOSE: To analyze self and 360-evaluation scores of the professionalism intelligence model domains within an academic Otolaryngology-Head and Neck Surgery Department. METHODS: A leadership course was introduced within the Department of Head and Neck Surgery & Communication Sciences at Duke University Medical Center. A 360 evaluation assessing domains of the professional intelligence model was recorded for all participants. Participant demographics included gender (male vs female), generation group (generation Y vs older generations) and physician status of participants (physician vs non-physician). Differences in mean self-scores were modeled using linear regression. When analyzing the evaluator scores, gaps were defined as self-score minus evaluator-score for each member of a participant's evaluator groupings (supervisor, peer, and direct report). Two types of linear mixed models were fit with a random intercept to account for the correlated gaps in the same participant. RESULTS: Scores of 50 participants and 394 evaluators were analyzed. The average age was 40.6 (standard deviation 9.3) years, and 50% (N=25) of participants were females. Physicians accounted for 36% (N=18) of the cohort, and 61% (N=11) of physicians were residents. Physicians scored themselves lower than non-physicians when assessing leadership intelligence, interpersonal relations, empathy, and focused thinking. On average, participants under-rated themselves compared to their evaluators with direct reports giving higher scores than managers and peers. When compared with generation Y, older generations tended to rate themselves lower than their peers and managers in cognitive intelligence. No significant association was observed between gender and any scores. CONCLUSION: Participants rate themselves lower on average than their evaluators. This work is important in understanding how perceived leadership qualities are assessed and developed within an academic surgical department. Finally, the results presented could serve as a model to address the gap between self- and other-perceptions of defined leadership virtues in future leadership development activities.

Survival outcomes in sinonasal carcinoma with neuroendocrine differentiation: A NCDB analysis.

BACKGROUND: Sinonasal carcinoma with neuroendocrine differentiation (SCND) is a rare group of tumors with poor prognosis. Treatment and sequence of therapies are still unclear. The goal of this study is to analyze treatment outcomes in SCND using a national database. METHODS: The National Cancer Database was queried for SCND from 2004 to 2014. Patient demographics, tumor characteristics and treatment paradigms were tabulated. Multivariable Cox proportional hazards regression was performed for statistical analysis of treatment regimen on overall survival (OS). RESULTS: A total of 415 patients were identified. Most patients were male (61.2%), with a median age of 58 years and the most common primary site was the nasal cavity (52.5%). T4 tumors were observed in 67.7% of cases. Unimodality (41.9%) and bimodality (43.9%) therapies were the most common treatment modalities. Radiation therapy was the only treatment administered in 30% of the patients, while 27.2% received definitive chemoradiation (CRT) and 11.6% had surgery with adjuvant CRT. In our Cox-PH model, age (HR = 1.04, p < 0.001), T4 (HR = 2.6, p = 0.004) and N2/N3 (HR = 2.18, p = 0.001) were associated with worse survival. Trimodality (HR = 0.49, p = 0.005) and bimodality (HR = 0.65, p = 0.009) therapies had a better OS compared to unimodality. Patients treated with definitive CRT or surgery with adjuvant CRT had a significant increase in OS (p = 0.01 and 0.002 respectively). CONCLUSION: SCND appears to be best treated using a multimodality approach with definitive CRT or surgery followed by CRT. Neoadjuvant chemotherapy could be helpful in selecting the best treatment strategy.

Sinus Irrigation Penetration After Proposed Modified Draf IIa Technique in a Side-to-Side Cadaveric Model.

BACKGROUND: Endoscopic sinus surgery (ESS) is an effective intervention for patients with medically refractory chronic rhinosinusitis. Frontal sinusotomy is the most challenging part of ESS, with one of the key outcomes being access for topical irrigations. OBJECTIVE: The purpose of this study is to compare irrigation penetration into the frontal sinus following Draf IIa versus modified Draf IIa frontal sinusotomy. METHODS: Four fresh cadaver heads were used in this experiment. Draf IIa was performed on one side of each head and a modified Draf IIa on the contralateral side. This proposed modification consists of a Draf IIa combined with an agger nasi punch-out procedure and partial trimming of the vertical lamella of the middle turbinate back to the posterior table of the frontal sinus without drilling the beak. Each head was irrigated with methylene blue-dyed water and recorded by rigid endoscopy through an endonasal view (EV) of the frontal sinus and frontal trephination view (TV). Two blinded rhinologists scored the extent of staining (using an ordinal scale of 0 to 3) for each side. A case report where the modified Draf IIa was performed is also described. RESULTS: After modified Draf IIa sinuosotomy, the mean score for the EV was 2.125 and for the TV was 2, versus 0.875 and 0.625 for traditional Draf IIa, respectively. There was a statistically significant increase for both EV (p = 0.019) and TV (p = 0.018) after modified Draf IIa. CONCLUSION: In our cadaveric model, this procedural modification improved penetration of postoperative irrigations into the frontal sinus. This simple technique may be easily adapted into frontal ESS when indicated.

Survival Outcomes in Sinonasal Poorly Differentiated Squamous Cell Carcinoma.

OBJECTIVE: Sinonasal squamous cell carcinoma (SCC) is rare with no consensus on treatment regimen. Our goal is to analyze treatment outcomes in poorly differentiated SCC (PDSCC) using a large national database. STUDY DESIGN: Retrospective database study. METHODS: The National Cancer Database was queried for sinonasal invasive SCC, grade 3 (poorly differentiated) from 2004 to 2014. Patient demographics and tumor and treatment characteristics were tabulated. Kaplan-Meier (KM) analysis was performed to compare overall survival (OS) between histology subtype and primary site. Multivariable Cox proportional hazards regression was performed for statistical analysis of treatment regimen on OS. RESULTS: A total of 1,074 patients were identified. The maxillary sinus was the most common site (45%). T4 tumors were observed in 50% of patients, with most patients treated at high-volume facilities (77%). In KM analysis, spindle cell SCC histological subtype, primary tumors of the maxillary sinus, and poorly differentiated grade had worse OS. In our Cox-PH model, higher T stage and age were associated with worse OS. Those treated at a high-volume facility and those who underwent surgical resection followed by adjuvant radiation had improved OS. Chemotherapy within the treatment regimen did not confer survival benefit except in surgical patients when positive margins were present, and surgery with adjuvant chemoradiation trended toward improved survival. CONCLUSIONS: Sinonasal PDSCC appears to be best treated at high-volume centers with surgical resection followed by adjuvant radiation. Poorly differentiated grade has worse OS compared to more differentiated tumors. Chemotherapy along with adjuvant radiation may have a role in patients with positive surgical margins. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1040-E1048, 2021.

Sinonasal Squamous Cell Carcinoma Outcomes: Does Treatment at a High-Volume Center Confer Survival Benefit?

OBJECTIVE: To determine whether treatment of sinonasal squamous cell carcinoma (SCC) at a high-volume facility affects survival. STUDY DESIGN: Retrospective database analysis. SETTING: National Cancer Database (2004-2014). SUBJECTS AND METHODS: The National Cancer Database was queried for sinonasal SCC from 2004 to 2014. Patient demographics, tumor characteristics and classification, resection margins, treatment regimen, and facility case-specific volume-averaged per year and grouped in tertiles as low (0%-33%), medium (34%-66%), and high (67%-100%)-were compared. Overall survival was compared with Cox proportional hazards regression analysis. RESULTS: A total of 3835 patients treated for sinonasal SCC between 2004 and 2014 were identified. Therapeutic options included surgery alone (18.6%), radiotherapy (RT) alone (29.1%), definitive chemoradiation (15.4%), surgery with adjuvant RT (22.8%), and combinations (14.1%) of the aforementioned treatments. Patients who underwent surgery with adjuvant RT had better overall survival (hazard ratio [HR], 0.74; P < .001; 95% CI, 0.63-0.86). As for treatment volume per facility, 7.4% of patients were treated at a low-volume center, 17.5% at a medium-volume center, and 75.1% at a high-volume center. Univariate analysis showed that treatment at a high-volume facility conferred a significantly better overall survival (HR, 0.77; P = .002). Multivariable Cox proportional hazards regression analysis, adjusting for age, sex, tumor classification, and treatment regimen, demonstrated that patients who underwent treatment at a high-volume facility (HR, 0.81; P < .001) had significantly improved survival. CONCLUSION: This study shows a better overall survival for sinonasal SCC treated at high-volume centers. Further study may be needed to understand the effect of case volume on the paradigms of sinonasal SCC management.

Prospective use of Ablation Index targets improves clinical outcomes following ablation for atrial fibrillation.

AIMS: Late recovery of ablated tissue leading to reconnection of pulmonary veins remains common following radiofrequency catheter ablation for AF. Ablation Index (AI), a novel ablation quality marker, incorporates contact force (CF), time, and power in a weighted formula. We hypothesized that prospective use of our previously published derived AI targets would result in better outcomes when compared to CF-guided ablation. METHODS: Eighty-nine consecutive drug-refractory AF patients (49% paroxysmal) underwent AI-guided ablation (AI-group). AI targets were 550 for anterior/roof and 400 for posterior/inferior left atrial segments. Procedural and clinical outcomes of these patients were compared to 89 propensity-matched controls who underwent CF-guided ablation (CF-group). All 178 procedures were otherwise similar, and both groups were followed-up for 12 months. The last 25 patients from each group underwent analysis of all VisiTags™ for ablation duration, CF, Force-Time Integral, and impedance drop. RESULTS: First-pass pulmonary vein isolation (PVI) was more frequent in AI-group than in CF-group (173 [97%] vs. 149 [84%] circles, P < 0.001), and acute PV reconnection was lower (11 [6%] vs. 24 [13%] circles, P = 0.02). Mean PVI ablation time was similar (AI-group: 42 ± 9 vs. CF-group: 45 ± 14 minutes, P = 0.14). Median impedance drop for AI-group was significantly higher than in CF-group (13.7 [9-19] Ω vs. 8.8 [5.2-13] Ω, P < 0.001). Two major complications occurred in CF-group and none in AI-group. Atrial tachyarrhythmia recurrence was significantly lower in AI-group (15 of 89 [17%]) than in CF-group (33 of 89 [37%], P = 0.002). CONCLUSION: AI-guided ablation is associated with significant improvements in the incidence of acute PV reconnection and atrial tachyarrhythmia recurrence rate compared to CF-guided ablation, potentially due to creation of better quality lesions as suggested by greater impedance drop.

Prospective clinical and radiographic results of CHARITÉ III artificial total disc arthroplasty at 2- to 7-year follow-up: a Canadian experience.

BACKGROUND: Early and intermediate results have shown that the SB CHARITÉ III total disc arthroplasty (TDA) favourably compares to spinal fusion, but is associated with fewer complications and higher levels of satisfaction. We sought to prospectively report the clinical and radiographic results of the CHARITÉ III TDA after an average of 55 months follow-up. METHODS: We conducted a prospective study of patients receiving the CHARITÉ TDA at either L4-5 or L5-S1 between April 2001 and November 2006. The primary indication for surgery was discogenic low-back pain confirmed by provocative discography. Assessment included pre- and postoperative (3, 6 and 12 mo and yearly thereafter) validated patient outcome measures and radiographic review. RESULTS: Fifty-seven of the potential 64 (89%) patients were available for complete follow-up. Their mean age was 39 (range 21-59) years. A statistically significant improvement was demonstrated between all the mean pre- and postoperative intervals for the Oswestry Disability Index, visual analogue scale for back and leg pain, and Short Form-36 health survey (p < 0.001). The mean sagittal rotation was 6.5° (range 0.5°-22.4°), and the mean intervertebral translation was 1.1 mm (range 0-2.4 mm). Subsidence of the implant was present in 44 of 53 (83%) patients with an L5-S1 disc arthroplasty. The mean subsidence was 1.7 mm (range 0-4.8 mm). CONCLUSION: The 2- to 7-year follow-up of this cohort of patients demonstrated satisfactory clinical and radiographic results in a carefully selected patient population. The radiographic assessment confirmed preservation and maintenance of motion at the replaced disc during the period of follow-up.