Survey of major complications after prone transpsoas surgery: an analysis of early adopters' practice.

INTRODUCTION: The prone transpsoas technique (PTP) is a modification of the traditional lateral lumbar interbody fusion approach, which was first published in the literature in 2020. The technique provides several advantages, such as lordosis correction and redistribution, single-position surgery framework, and ease of performing posterior techniques when needed. However, the prone position also leads to the movement of some retroperitoneal, vascular, and neurological structures, which could impact the complication profile. Therefore, this study aimed to investigate the occurrence of major complications in the practice of early adopters of the PTP approach. METHODS: A questionnaire containing 8 questions was sent to 50 participants and events involving early adopters of the prone transpsoas technique. Of the 50 surgeons, 32 completed the questionnaire, which totaled 1963 cases of PTP surgeries. RESULTS: Nine of the 32 surgeons experienced a major complication (28%), with persistent neurological deficit being the most frequent (7/9). Of the total number of cases, the occurrence of permanent neurological deficits was approximately 0,6%, and the rate of vascular and visceral injuries were both 0,05% (1/1963 for each case). CONCLUSION: Based on the analysis of the questionnaire responses, it can be concluded that PTP is a safe technique with a very low rate of serious complications. However, future studies with a more heterogeneous group of surgeons and a more rigorous linkage between answers and patient data are needed to support the findings of this study.

Lateral versus posterior approaches to treat degenerative lumbar pathologies-systematic review and meta-analysis of recent literature.

INTRODUCTION: The lateral lumbar interbody fusion arose as a revolutionary approach to treating several spinal pathologies because the techniques were able to promote indirect decompression and lordosis restoration through a minimally invasive approach allowing for reduced blood loss and early recovery for patients. However, it is still not clear how the technique compares to other established approaches for treating spinal degenerative diseases, such as TLIF, PLIF, and PLF. MATERIAL AND METHODS: This is a systematic review and meta-analysis of articles published in the last 10 years comparing lateral approaches to posterior techniques. The authors included articles that compared the LLIF technique to one or more posterior approaches, treating only degenerative pathologies, and containing at least one of the key outcomes of the study. Exclusion articles that were not original and the ones that the authors could not obtain the full text; also articles without the possibility to calculate the standard deviation or mean were excluded. For count variables, the odds ratio was used, and for continuous variables, the standard means difference (SMD) was used, and the choice between random or fixed-effects model was made depending on the presence or not of significant (p < 0.05) heterogeneity in the sample. RESULTS: Twenty-four articles were included in the quantitative review. As for the intra-/perioperative variables, the lateral approaches showed a significant reduction in blood loss (SMD-1.56, p < 0.001) and similar operative time (SMD = - 0.33, p = 0.24). Moreover, the use of the lateral approaches showed a tendency to lead to reduced hospitalization days (SMD = - 0.15, p = 0.09), with significantly reduced odds ratios of complications (0.53, p = 0.01). As for the clinical outcomes, both approaches showed similar improvement both at improvement as for the last follow-up value, either in ODI or in VAS-BP. Finally, when analyzing the changes in segmental lordosis and lumbar lordosis, the lateral technique promoted significantly higher correction in both outcomes (p < 0.05). CONCLUSION: Lateral approaches can promote significant radiological correction and similar clinical improvement while reducing surgical blood loss and postoperative complications.

Radiographic alignment outcomes after the single-position prone transpsoas approach: a multi-institutional retrospective review of 363 cases.

OBJECTIVE: The aim of this paper was to evaluate the changes in radiographic spinopelvic parameters in a large cohort of patients undergoing the prone transpsoas approach to the lumbar spine. METHODS: A multicenter retrospective observational cohort study was performed for all patients who underwent lateral lumber interbody fusion via the single-position prone transpsoas (PTP) approach. Spinopelvic parameters from preoperative and first upright postoperative radiographs were collected, including lumbar lordosis (LL), pelvic incidence (PI), and pelvic tilt (PT). Functional indices (visual analog scale score), and patient-reported outcomes (Oswestry Disability Index) were also recorded from pre- and postoperative appointments. RESULTS: Of the 363 patients who successfully underwent the procedure, LL after fusion was 50.0° compared with 45.6° preoperatively (p < 0.001). The pelvic incidence-lumbar lordosis mismatch (PI-LL) was 10.5° preoperatively versus 2.9° postoperatively (p < 0.001). PT did not significantly change (0.2° ± 10.7°, p > 0.05). CONCLUSIONS: The PTP approach allows significant gain in lordotic augmentation, which was associated with good functional results at follow-up.

Comparison of segmental lordosis gain of prone transpsoas (PTP) vs. lateral lumbar interbody fusion.

INTRODUCTION: Lumbar interbody fusion is a standard method to treat certain degenerative conditions that are refractory to conservative treatments. LLIF reduces posterior muscle damage, can relieve neurological symptoms through indirect decompression, provides increased stability with its wider cages, and promotes more significant segmental lordosis than standard posterior techniques. However, the technique possesses its issues, such as unusual positioning, possible plexus-related symptoms, and median segmental lordosis correction. Trying to ease those issues, the idea of a prone transpsoas technique occurred. METHODS: Retrospective, single-centric, comparative, and non-randomized study. The authors paired patients receiving lateral lumbar interbody fusion (LLIF) or prone transpsoas (PTP) to evaluate the technique's impact on the segmental lordosis correction. A correlation test selected the covariates for the matching. p-Values inferior to 0.05 were deemed significant. RESULTS: Seventy-one patients were included in the analysis, 53 in the LLIF group and 18 in the PTP group. The significant covariates to the segmental lordosis correction were technique, preoperative segmental lordosis, cage position, and preoperative pelvic tilt. After the paring model, PTP showed significant segmental lordosis correction potential regarding the LLIF. CONCLUSION: The prone transpsoas approach can significantly enhance the correction of segmental lordosis proportionated to the traditional LLIF approach.

Minimally invasive versus open surgery for degenerative lumbar pathologies:a systematic review and meta-analysis.

INTRODUCTION: With the increase in life expectancy and consequent aging of the population, degenerative lumbar spine diseases tend to increase its number exponentially. Several treatment options are available to treat degenerative spinal diseases, such as laminectomies, posterior fusions, and interbody fusions, depending on their locations, correction necessities, and surgeon philosophy. With the advance in technology and surgical knowledge, minimally invasive techniques (MIS) arose as a solution to reduce surgical morbidity, while maintaining the same benefits as the traditionally/open surgeries. Several studies investigated the possible advantages of MIS techniques against the traditional open procedures. However, those articles are usually focused only on one technique or on one pathology. METHODS: The electronic databases, including PubMed, Google Scholar, Ovid, and BVS, were systematically reviewed. Only original articles in English or Portuguese were added to the review, the revision was performed following the PRISMA guideline. RESULTS: Fifty-three studies were included in the meta-analysis. Of the studied outcomes the Length of Stay Odds of complications, Blood Loss, and Surgery costs presented significantly favored MIS approaches, while the Last FUP ODI score, and Surgery Time did not differ among the groups. CONCLUSION: Minimally invasive techniques are a remarkably interesting option to traditional open surgeries, as these procedures showed a significant reduction in blood loss, hospitalization time, complications, and surgical costs.

Single-position prone transpsoas fusion for the treatment of lumbar adjacent segment disease: early experience of twenty-four cases across three tertiary medical centers.

PURPOSE: Prone transpsoas fusion (PTP) is a minimally invasive technique that maximizes the benefit of lateral access interbody surgery and the prone positioning for surgically significant adjacent segment disease. The authors describe the feasibility, reproducibility and radiographic efficacy of PTP when performed for cases of lumbar ASD. METHODS: Adult patients undergoing PTP for treatment of lumbar ASD at three institutions were retrospectively enrolled. Demographic information was recorded, as was operative data such as adjacent segment levels, operative time, blood loss, laterality of approach, open versus percutaneous pedicle screw instrumentation and need for primary decompression. Radiographic measurements including segmental and global lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope and sagittal vertical axis were recorded both pre- and immediately post-operatively. RESULTS: Twenty-four patients met criteria for inclusion. Average age was 60.4 ± 10.4 years and average BMI was 31.6 ± 5.0 kg/m2. Total operative time was 204.7 ± 83.3 min with blood loss of 187.9 ± 211 mL. Twenty-one patients had pedicle screw instrumentation exchanged percutaneously and 3 patients had open pedicle screw exchange. Two patients suffered pulmonary embolism that was treated medically with no long-term sequelae. One patient had transient lumbar radicular pain and all patients were discharged home with an average length of stay of 3.0 days (range 1-6). Radiographically, global lumbar lordosis improved by an average of 10.3 ± 9.0 degrees, segmental lordosis by 10.1 ± 13.3 degrees and sagittal vertical axis by 3.2 ± 3.2 cm. CONCLUSION: Single-position prone transpsoas lumbar interbody fusion is a clinically reproducible minimally invasive technique that can effectively treat lumbar adjacent segment disease.

The prone transpsoas technique: preliminary radiographic results of a multicenter experience.

INTRODUCTION: The lateral lumbar interbody fusion (LLIF) is a safe and effective technique to treat a vast range of lumbar disorders. However, the technique is also burdened by some problems. A new approach to the lateral lumbar interbody fusion was devised to solve or reduce some of the problems regarding the lateral approach. Its principal difference from the standard LLIF relies on positioning the patient in a prone decubitus, which might lead to an increase in the intradiscal lordosis. METHODS: A retrospective, multicentric, non-randomized study to evaluate segmental and regional lordosis following prone transpsoas (PTP) approach to LLIF. All patients undergoing prone transpsoas surgery at the involved institutions were included. Patients with low-quality images not allowing the measurements of the required spinopelvic parameters were excluded. Measurements included pre- and postoperative index-level segmental lordosis, lumbar lordosis, pelvic incidence, and pelvic tilt. RESULTS: Thirty-two (32) patients were included in the study, in which 23 underwent single-level, six (6) underwent two-level, Two (2) underwent three-level, and one underwent four-level PTP. Mean index level segmental lordosis increased from 8.7° to 14.8°(p < 0.001); lumbar lordosis (L1-S1) increased from 42.1° to 45.8° (p = 0.11), although after excluding an outlier value L1-S1 lordosis results were 41.9° pre-op to 46.7° post-op (p = 0.003). Twenty-two (22) patients had a pre-op PI-LL mismatch of 10° or more, while at the postoperative visit, only 12 patients had a mismatch outside of 10° (p = 0.01). CONCLUSION: The prone transpsoas technique is feasible and is associated with a significant gain of segmental lordosis and correction of spinopelvic alignment parameters.

Three-Dimensional Assessment of Cervical Vertebrae Anomalies in Patients With Cleft Lip and Palate.

OBJECTIVE: To evaluate the occurrence of cervical vertebrae anomalies (CVA) in patients with unilateral (UCLP) and bilateral cleft lip and palate (BCLP) using cone beam computed tomography (CBCT) examinations. DESIGN: Retrospective assessment of CBCT images. Descriptive statistics were calculated. Fisher exact test or χ2 test was performed to evaluate the differences among each CVA between sex and type of cleft. SETTING: School of Dentistry. PARTICIPANTS: One hundred fifty-one patients with cleft lip and palate (103 UCLP/48 BCLP). INTERVENTIONS: No relevant intervention. MAIN OUTCOME MEASURES: Cone beam computed tomography images were assessed for the presence or absence of 12 most commonly observed CVA: spina bifida, dehiscence, cleft of the posterior arch, cleft of the anterior arch, fusion between cervical vertebrae, block fusion, occipitalization, narrowing of the intervertebral space, posterior ponticle, os odontoideum, ossiculum terminale, and subdental cartilaginous remnants. RESULTS: The presence of subdental cartilaginous remnants was the most frequently observed alteration-found in 81.45% of the sample-and it was the only CVA with statistically significant frequencies in the individuals with BCLP. Considering only the other CVA, 22.51% presented 1 and 5.29% presented 2 or more CVA. CONCLUSIONS: Patients with cleft lip and palate may present an overall high incidence of CVAs. However, when comparing the distribution of the CVAs among sex and types of cleft, the only significant difference noted was a higher incidence of subdental cartilaginous remnants among patients with BCLP.

Three-dimensional tomographic assessment of the upper airway using 2 different imaging software programs: A comparison study.

INTRODUCTION: Several imaging software programs with different tools are available for upper airway (UAW) analysis by means of cone beam computed tomography. Because of this wide variability, this study aimed to compare the reproducibility of two of the most used software programs on UAW segmentation, that is, Dolphin Imaging (Dolphin Imaging and Management Solutions, Chatsworth, Calif) and Mimics Research (Materialise, Leuven, Belgium). METHODS: The sample consisted of 50 scans of adult subjects with Class III malocclusion; pharyngeal volume and minimal cross-sectional area (mCSA) were assessed twice by 2 experienced evaluators using both software programs. Intra- and intersoftware and/or evaluator agreement were calculated using the intraclass correlation coefficient (ICC). Bland-Altman analysis was used to visualize the intersoftware and interevaluator agreement. RESULTS: Using Mimics Research and Dolphin Imaging, the respective mean values of volume (cm3) were 27.1 ± 8.4 and 24.7 ± 8.1 (P < 0.05) and of mCSA (mm2) were 167.8 ± 95.5 and 176.5 ± 102.3 (P < 0.05). Although differences between software packages were observed on both the analyzed variables, the results showed a high intersoftware agreement, with ICC of 0.87 (volume) and 0.97 (mCSA) and mean bias of 24.6 (volume) and -8.8 (mCSA). A high intrasoftware agreement was also observed, with values varying from 0.83 to 0.99. Excellent intra- and interevaluator agreement was also obtained, with ICC values from 0.93 to 0.99. CONCLUSIONS: Dolphin Imaging and Mimics Research individually provide highly reproducible results, with clinically acceptable agreement between them for UAW segmentation, providing consistent values for volume and mCSA.

Correction to: The prone transpsoas technique: preliminary radiographic results of a multicenter experience.

Unfortunately, the third and fourth author names have been incorrectly published in the original publication. The complete correct names are given below.

Craniofacial characterization of Marfan Syndrome.

OBJECTIVE: The morbidity and mortality associated with the Marfan Syndrome (MFS) warrant timely diagnosis and intervention that can improve long-term prognosis. The aim of this study was to test the hypothesis that a distinct craniofacial morphology exists for patients with MFS that can be described quantitatively and qualitatively. METHODS: Subjects with a positive diagnosis of MFS were recruited for this study (N = 36). Craniofacial anthropometric measurements were made on each subject and compared to established norms of age- and sex-matched controls using z-scores calculated for measurements of MFS patients. Lateral and frontal photographs were obtained to make qualitative assessments and describe facial features of subjects, and a clinical examination was completed to document occlusal relationships. RESULTS: The subjects were primarily female (58%) ranging in age between 4 and 57 years (mean age 10.7 ± 6.0 years). Comparison of craniofacial measurements revealed that for 10 of the 12 measurements, ≥65% of the study population had a z-score of ± 2 and fell within the normal range for facial dimension. For 2 of the 12 measurements, over half of the subjects fell outside of the normal range (z-score < -2 or > 2) for facial dimension. Specifically, the majority of participants resided in the supernormal category for biocular width and the subnormal category for width of the face. Photographic assessment revealed retrognathia (54%) and down-slanting palpebral fissures (62%) were most prevalent in MFS patients. CONCLUSION: Our data suggest there are quantitative differences in the facial morphology of patients with MFS when compared to a control population.

Academic Achievement Among Children With Nonsyndromic Orofacial Clefts : A Population-Based Study.

OBJECTIVE: Children with orofacial clefts (OFCs) may experience poor reading proficiency, learning disabilities, and academic underachievement. We examined the association between nonsyndromic (NS) OFCs and end-of-grade (EOG) performance in reading and math from third through eighth grade in a sample subgroup. PARTICIPANTS: We identified a cohort of 559 children with NS-OFCs and 6822 children without birth defects, classifying cleft type by cleft lip alone, with or without cleft alveolar ridge (CL); cleft lip with cleft palate (CL+P); and cleft palate only (CP). MAIN OUTCOME MEASURES: Using logistic regression, we estimated the odds of not meeting grade-level standards among children with NS-OFCs compared to unaffected peers. Using longitudinal analyses, we estimated the odds of not meeting grade-level standards and average change in test scores through eighth grade. RESULTS: Children with NS-OFCs were 1.22 (95% CI: 0.96, 1.83) times as likely not to meet grade-level standards in reading compared to unaffected peers. The effect was similar for math (OR: 1.17; 95% CI: 0.92, 1.48). Children with CL+P were 1.33 (95% CI: 0.86, 1.83) and 1.74 (95% CI: 1.19, 2.56) times as likely not to meet grade-level standard in reading and in both subjects, respectively, compared to unaffected peers. The average rate of change in both scores was similar for children with and without OFCs. CONCLUSIONS: Poor academic performance appears greatest for children with CL+P, a finding compatible with previous observations and hypothesized mechanisms associating orofacial clefts with subtle abnormalities in brain development. Academic performance monitoring and referral for academic assistance is warranted.

Issues involved in the phenotypic classification of orofacial clefts ascertained through a state birth defects registry for the North Carolina Cleft Outcomes Study.

BACKGROUND: Epidemiologic studies involving birth defects are extremely sensitive to phenotype accuracy and precision. We devised a case review and classification protocol for a project to study school achievement in children with idiopathic, nonsyndromic orofacial clefts to improve the reliability of phenotypic classification from the statewide birth defects registry. METHODS: Surveillance-program abstraction data and medical records at the birth or treating hospitals were used when available. Exclusion criteria included: median cleft lip; Tessier cleft; premaxillary agenesis; presence of a recognizable syndrome, phenotype, association, or sequence (other than Robin sequence); clefts with other malformations not considered to be normal or common variants in the newborn; and cases with documented or suspected genetic or teratogenic causes. RESULTS: Of 712 children identified with orofacial clefts, 153 were excluded, leaving 559 nonsyndromic orofacial cleft cases of unknown cause in the final study. These cases were grouped into the following clinically meaningful types: cleft lip with or without cleft alveolus; cleft lip and cleft palate; and cleft palate only. This review and classification process resulted in the elimination of 21.5% of the original cohort of identified cases, with most exclusions being due to suspected syndromic associations. CONCLUSION: Verbatim descriptions of the clinical findings are critical for accurate classification of diagnoses. This review process improved the precision of orofacial cleft phenotype classification for our study. Precision would have been further improved if all of the cases had verbatim descriptions of diagnoses and all medical records could have been reviewed by the classification team.

Radiographic outcomes of anterior column realignment for adult sagittal plane deformity: a multicenter analysis.

PURPOSE: Anterior column reconstruction (ACR) is a minimally invasive technique for the treatment of sagittal plane deformity. ACR uses a lateral transpsoas approach with ALL release and the application of an interbody device to achieve correction. Here, we present 1-year radiographic results from a multicenter study of adult spinal deformity (ASD) patients. METHODS: A multicenter database was queried from 2005 to 2013 for ASD patients treated with ACR. Demographics, surgical data, and radiographic measurements were collected and retrospectively analyzed. Radiographic time points included preoperative (pre-op), postoperative (post-op; first visit prior to 3 months), and last follow-up (last FU; minimum of 1 year). Sagittal radiographic measurements included regional lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), T1 spinopelvic inclination (T1SPi), and segmental lordosis (disc angle). RESULTS: Mean patient age was 67.4 years (range 46.5-80.0) and 11 patients (32.4 %) were male. Twenty patients (58.8 %) had previous lumbar surgery. All patients had a minimal of one-level ACR with ALL release (mean 1.7; range 1-4). Mean number of lateral interbody fusion (LLIF) levels without ALL release per patient was 0.7 (range 0-3). Thirty-three patients (97.1 %) received supplemental posterior fixation and 1 patient (2.9 %) had lateral fixation only. In 26 patients (76.5 %), supplemental posterior fixation was performed using an open approach, and 7 patients (20.6 %) were treated with percutaneous placement. Mean of number of levels fused was 7.1 (range 2-16). There was a significant improvement in LL (p < 0.001), PI-LL mismatch (p < 0.001), and PT (p = 0.03) from pre-op to post-op, and pre-op to last FU. There was no change in T1SPi, SS, or PI. Segmental lordosis improved at ACR levels from mean of -2.2° pre-op to -16.0° post-op (p < 0.01) and -16.3° at last FU (p < 0.001). The addition of posterior column osteotomy increased the change in segmental lordosis with ACR by 72.7 % (p < 0.001). LLIF without ALL release led to significant improvement in segmental lordosis from pre-op (-2.4°) to post-op (-7.1°; p < 0.01) but not from pre-op to last FU (-5.7°; p = 0.06). CONCLUSION: ACR successfully restores lumbar lordosis in ASD patients with sagittal imbalance. ACR results in greater segmental correction than is achieved with LLIF alone. Supplementing with posterior osteotomies allows for even greater correction. The ability to achieve the desired radiographic goals is expected to improve as technical nuances are refined and patient selection is optimized.

Anterior column realignment following lateral interbody fusion for sagittal deformity correction.

Degenerative and iatrogenic diseases may lead to loss of lordosis or even kyphotic thoracolumbar deformity and sagittal misalignment. Traditional surgery with three-column osteotomies is associated with important neurologic risks and postoperative morbidity. In a novel technique, the lateral transpsoas interbody fusion (LTIF) is complemented with the sacrifice of the anterior longitudinal ligament and anterior portion of the annulus followed by the insertion of a hyperlordotic interbody cage. This is a less invasive lateral technique named anterior column realignment (ACR) and aims to correct sagittal misalignment in adult spinal deformity (ASD), with or without the addition of minor posterior osteotomies. In this article, we provide an account of the evolution to the ACR technique, the literature, and the Brazilian experience in the treatment of adult spinal deformity with this novel advanced application of LTIF. In the presence of ASD, the risk-to-benefit ratio of a surgical correction must be evaluated. Less invasive surgical strategies can be alternatives to treat the deformity and provide better quality of life to the patient. ACR is an advanced application of lateral transpsoas approach, up to date has shown to be reliable and effective when used for ASD, and may minimize complications and morbidity from traditional surgical procedures. Long-term follow-up and comparative studies are needed to evaluate real benefit.

Is the lateral transpsoas approach feasible for the treatment of adult degenerative scoliosis?

BACKGROUND: Lumbar degenerative scoliosis is a common condition in the elderly. Open traditional surgical approaches are associated with high-morbidity complication rates. Less invasive options may carry fewer risks in this patient population. A minimally disruptive lateral transpsoas retroperitoneal technique to accomplish interbody fusion was developed to avoid the morbidity of traditional open surgery, but this approach as an anterior stand-alone construction has not been reported yet for the treatment of adult degenerative scoliosis. QUESTIONS/PURPOSES: We determined (1) the clinical outcomes (VAS scores for back and leg, Oswestry Disability Index), (2) the radiographic outcomes (Cobb angle, lumbar lordosis, sacral slope, high-grade subsidence, osseous fusion), and (3) the reoperation and complication rates in an older population undergoing this surgical approach. METHODS: Between 2004 and 2008, 62 patients were treated surgically for adult degenerative scoliosis, of whom 46 (74%) were treated with stand-alone lateral lumbar interbody fusion; 11 of these (24%) were lost to followup before 24 months, leaving the records of 35 patients (nine men, 26 women; mean ± SD age, 68 ± 10 years) available for this retrospective review. General indications for this approach included neurogenic claudication and radicular symptoms with history of chronic low-back pain. A total of 107 levels were treated (mean, three; range, one to seven). Clinical and radiographic outcomes were assessed at a followup of 24 months. RESULTS: Mean VAS back pain scores improved from 85 mm preoperatively to 27 mm at latest followup (p < 0.001). VAS leg pain scores improved from 91 mm to 24 mm (p < 0.001). Oswestry Disability Index scores improved from 51 to 29 (p < 0.001). Coronal alignment improved from Cobb angles of 21° to 12° (p < 0.001). Lumbar lordosis improved from 33° to 41° (p < 0.001). Sacral slope was enhanced from 28° to 35° (p < 0.001). Fusion rate was 84% at final evaluation. High-grade subsidence was seen in 10 patients (29%). Three patients (9%) needed further surgical intervention. CONCLUSIONS: Use of the lateral approach achieved reasonable coronal and sagittal correction, as well as improvements in pain and function, in mild scoliotic deformities; however, subsidence was a concern, occurring in 29% of patients. Questions still remain regarding the need for additional supplementation or the use of wider cages to prevent subsidence. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Microtensile bond strength of etch-and-rinse and self-etch adhesives to artificially created carious dentin.

This article evaluates a pH-cycling model for simulation of caries-affected and caries-infected dentin (CAD and CID, respectively) surfaces, by comparing the bond strength of an etch-and-rinse and a self-etch adhesive system. For both adhesives, bonding to sound dentin (SD) showed that the microtensile bond strength (µTBS) values of SD, CAD, and CID were SD > CAD > CID (P < 0.05). Knoop microhardness number mean values followed the same trend. Adhesive systems were not able to totally penetrate into CAD and CID, forming more irregular resin-dentin interdiffusion zones and atypical resin tags than SD. The tested in vitro pH-cycling caries model allowed the evaluation of specific dentin substrate alterations in response to µTBS. The type of dentin and its histological structure played an important role in etch-and-rinse and self-etch bonding, as lower µTBS values were attained in CAD and CID.

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

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

Risk of Injury to Retroperitoneal Structures in Prone and Lateral Decubitus Transpsoas Approaches to Lumbar Interbody Fusion: A Pilot Cadaveric Anatomical Study.

Introduction The retroperitoneal approach for lateral lumbar interbody fusion (LLIF) originally described an initial posterolateral fascial incision enabling finger dissection from behind the peritoneum and guidance of instruments through a second direct-lateral fascial incision. It has since become common for single direct-lateral incisional access to the retroperitoneum. This study attempted to quantify the distance of the peritoneum from posterior landmarks in the space, assess the risk of peritoneal violation in each access trajectory (i.e., posterolateral versus direct lateral retroperitoneal dissection), and determine whether there are differences based on patient position (prone versus lateral decubitus). Methods In three prone cadaveric torsos, Steinman pins were percutaneously placed mid-disc at each level L2-5 bilaterally (for a total of 18 prone approaches). Open dissections exposed the retroperitoneum including the quadratus lumborum and psoas muscles, maintaining the natural reflection of the peritoneum. Visual assessment qualified whether any pin violated any retroperitoneal structure. Distance from the anterior border of the quadratus lumborum to the posterior-most reflection of the peritoneum was measured. For comparison, three additional torsos were positioned in lateral decubitus, and the above steps were repeated, only unilaterally (for a total of nine lateral decubitus approaches). Results In prone, no pin violated the peritoneum; three (3/18 total approaches) violated the kidney, all at L2-3 (3/6 approaches at L2-3). In lateral decubitus, all three L2-3 pins violated the kidney (3/3 approaches at L2-3); five of the six remaining pins from L3-5 violated the peritoneum (totaling eight violations in the nine total approaches). The incidence of any violation was significantly greater in lateral decubitus vs. prone (8/9 vs. 3/18, p=0.0006). The structure at risk (kidney vs. peritoneum) was significantly associated with disc level (p=0.0041): all kidney violations occurred at L2-3 and all peritoneal violations occurred at L3-4 or L4-5. Distance from the quadratus lumborum to the posterior-most reflection of the peritoneum averaged 8.7 cm (range: 6-10) in prone, and 2.9 cm (range: 2.5-3.2) in lateral decubitus (p=0.0129). Conclusion A cadaveric study of retroperitoneal anatomy demonstrates that there is an increased distance from the quadratus lumborum to the peritoneum in prone versus lateral decubitus and that the trajectory of approach to the lumbar discs risks violation of the peritoneum more frequently when accessing directly laterally versus posterolaterally. In either approach, care should be taken to identify and release the peritoneal reflection to create a safe passage to the lumbar discs.

Effects of 3D Airway Geometry on the Airflow of Adults with Cleft Lip and Palate and Obstructive Sleep Apnea: A Functional Imaging Study.

Objective Individuals with cleft lip and palate (CLP) are at a high risk of developing obstructive sleep apnea (OSA). Hypothetically, the severity of OSA might be associated with the morphology of the upper airway (UAW) and the characteristics of the airflow. Thus, the present study aimed to assess and compare, in adults with CLP and skeletal class-III discrepancy, with or without OSA, simulations of airflow resistance and pressure according to the geometrical characteristics of the UAW and cephalometric parameters. Materials and Methods According to the results of type-I polysomnography tests, the sample ( n = 21) was allocated in 2 groups: 1) without OSA (N-OSA; n = 6); and 2) with OSA (OSA; n = 15). Cephalometric measurements were performed on the cone-beam computed tomography (CBCT) scans of the groups. After three-dimensional (3D) reconstructions, the volume (V) and minimal cross-sectional area (mCSA) of the UAW were generated. Computational fluid dynamics (CFD) simulations were used to assess key airflow characteristics. The results were presented at a significance level of 5%. Results The UAW pressure values and airway resistance did not differ between the groups, but there was a tendency for more negative pressures (26%) and greater resistance (19%) in the OSA group. Volume and mCSA showed a moderate negative correlation with resistance and pressure. The more inferior the hyoid bone, the more negative the pressures generated on the pharyngeal walls. Conclusion The position of the hyoid bone and the geometry of the UAW (V and mCSA) exerted effects on the airway-airflow resistance and pressure. However, key airflow characteristics did not differ among subjects with CLP, were they affected or not by OSA.