Human Rotator Cuff Tears Reveal an Age-Dependent Increase in Markers of Cellular Senescence and Selective Removal of Senescent Cells With Dasatinib + Quercetin Increases Genetic Expression of COL1A1 In Vitro.

PURPOSE: To quantify cellular senescence in supraspinatus tendon and subacromial bursa of humans with rotator cuff tears and to investigate the in vitro efficacy of the senolytic dasatinib + quercetin (D+Q) to eliminate senescent cells and alter tenogenic differentiation. METHODS: Tissue was harvested from 41 patients (mean age, 62 years) undergoing arthroscopic rotator cuff repairs. In part 1 (n = 35), senescence was quantified using immunohistochemistry and gene expression for senescent cell markers (p16 and p21) and the senescence-associated secretory phenotype (SASP) (interleukin [IL] 6, IL-8, matrix metalloproteinase [MMP] 3, monocyte chemoattractant protein [MCP] 1). Senescence was compared between patients <60 and ≥60 years old. In part 2 (n = 6) , an in vitro model of rotator cuff tears was treated with D+Q or control. D+Q, a chemotherapeutic and plant flavanol, respectively, kill senescent cells. Gene expression analysis assessed the ability of D+Q to kill senescent cells and alter markers of tenogenic differentiation. RESULTS: Part 1 revealed an age-dependent significant increase in the relative expression of p21, IL-6, and IL-8 in tendon and p21, p16, IL-6, IL-8, and MMP-3 in bursa (P < .05). A significant increase was seen in immunohistochemical staining of bursa p21 (P = .028). In part 2, D+Q significantly decreased expression of p21, IL-6, and IL-8 in tendon and p21 and IL-8 in bursa (P < .05). Enzyme-linked immunosorbent assay analysis showed decreased release of the SASP (IL-6, MMP-3, MCP-1; P = .002, P = .024, P < .001, respectively). Tendon (P = .022) and bursa (P = .027) treated with D+Q increased the expression of COL1A1. CONCLUSIONS: While there was an age-dependent increase in markers of cellular senescence, this relationship was not consistently seen across all markers and tissues. Dasatinib + quercetin had moderate efficacy in decreasing senescence in these tissues and increasing COL1A1 expression. CLINICAL RELEVANCE: This study reveals that cellular senescence may be a therapeutic target to alter the biological aging of rotator cuffs and identifies D+Q as a potential therapy.

Biomechanical evaluation of subscapularis peel repairs augmented with the long head of the biceps tendon for anatomic total shoulder arthroplasty.

BACKGROUND: Subscapularis failure is a troublesome complication following anatomic total shoulder arthroplasty (aTSA). Commonly discarded during aTSA, the long head of the biceps tendon (LHBT) may offer an efficient and cheap autograft for the augmentation of the subscapularis repair during aTSA. The purpose of this study was to biomechanically compare a standard subscapularis peel repair to 2 methods of subscapularis peel repair augmented with LHBT. METHODS: 18 human cadaveric shoulders (61 ± 9 years of age) were used in this study. Shoulders were randomly assigned to biomechanically compare subscapularis peel repair with (1) traditional single-row repair, (2) single row with horizontal LHBT augmentation, or (3) single row with V-shaped LHBT augmentation. Shoulders underwent biomechanical testing on a servohydraulic testing system to compare cyclic displacement, load to failure, and stiffness. RESULTS: There were no significant differences in the cyclic displacement between the 3 techniques in the superior, middle, or inferior portion of the subscapularis repair (P > .05). The horizontal (436.7 ± 113.3 N; P = .011) and V-shape (563.3 ± 101.0 N; P < .001) repair demonstrated significantly greater load to failure compared with traditional repair (344.4 ± 82.4 N). The V-shape repair had significantly greater load to failure compared to the horizontal repair (P < .001). The horizontal (61.6 ± 8.4 N/mm; P < .001) and the V-shape (62.8 ± 6.1; P < .001) repairs demonstrated significantly greater stiffness compared to the traditional repair (47.6 ± 6.2 N). There was no significant difference in the stiffness of the horizontal and V-shape repairs (P = .770). CONCLUSIONS: Subscapularis peel repair augmentation with LHBT autograft following aTSA confers greater time zero load to failure and stiffness when compared to a standard subscapularis peel repair.

Current Trends in Recombinant Human Bone Morphogenetic Protein 2 (rhBMP2) Usage for Spinal Fusion Surgery.

(1) Background: Since first approved by the FDA, on-label and off-label usage of recombinant human bone morphogenetic protein 2 (rhBMP2) for spinal fusion surgeries has become widespread. While many studies have investigated the safety and efficacy of its use, as well as its economic impact, few have looked at the current trends in its on- and off-label use. The goal of this study is to evaluate the current trends of on- and off-label rhBMP2 use for spinal fusion surgery. (2) Methods: A deidentified survey was created and electronically distributed to members of two international spine societies. Surgeons were asked to report their demographic information, surgical experience, and current usage of rhBMP2. They were then presented with five spinal fusion procedures and asked to report if they use rhBMP2 for these indications in their current practice. Responses were stratified between rhBMP2 users vs. non-users and on-label vs. off-label use. Data were analyzed using chi-square with Fisher's exact test for categorical data. (3) Results: A total of 146 respondents completed the survey with a response rate of 20.5%. There was no difference in overall rhBMP2 usage based on specialty, experience, or number of cases per year. Fellowship-trained surgeons and those who practice in the United States were more likely to use rhBMP2. Surgeons who were trained in the Southeast and Midwest regions reported the highest usage rates. rhBMP2 use was more common among fellowship-trained and US surgeons for ALIFs; non-US surgeons for multilevel anterior cervical discectomy and fusions; and fellowship-trained and orthopedic spine surgeons for lateral lumbar interbody fusions. Non-US surgeons were more likely to use rhBMP2 for off-label indications compared to surgeons from the US. (4) Conclusions: While various demographics of surgeons report different rates of rhBMP2 use, off-label use remains relatively commonplace amongst practicing spine surgeons.

Editorial Commentary: Machine Learning in Orthopaedics: Venturing Into the Valley of Despair.

Machine learning, a subset of artificial intelligence, has become increasingly common in the analysis of orthopaedic data. The resources needed to utilize machine-learning approaches for data analysis have become increasingly accessible to researchers, contributing to a recent influx of research using these techniques. As machine learning becomes increasingly available, misapplication owing to a lack of competence becomes more common. Sensationalized titles, misused vernacular, and a failure to fully vet machine learning-derived algorithms are just a few issues that warrant attention. As the orthopaedic community's knowledge on this topic grows, the flaws in our understanding of this field will likely become apparent, allowing for rectification and ultimately improvement of how machine learning is utilized in research.

Suture Tape Augmentation for the Repair of Index Finger Radial Collateral Ligament Injury: A Biomechanical Study.

PURPOSE: Despite their clinical importance in maintaining the stability of the pinch mechanism, injuries of the radial collateral ligament (RCL) of the index finger may be underrecognized and underreported. The purpose of this biomechanical study was to compare the repair of index finger RCL tears with either a standard suture anchor or suture tape augmentation. METHODS: The index fingers from 24 fresh-frozen human cadavers underwent repair of torn RCLs using either a standard suture anchor or suture tape augmentation. Following the repairs, the initial displacement of the repair with a 3-N ulnar deviating load was evaluated. Next, the change in displacement (cyclic deformation) of the repair after 1,000 cycles of 3 N of ulnar deviating force was calculated (displacement of the 1000th cycle - displacement of the first cycle). Finally, the amount of force required to cause clinical failure (30° ulnar deviation) of the repair was determined. RESULTS: Suture tape augmentation repairs displayed significantly less cyclic deformation (0.8 ± 0.5 mm) after cyclic loading than suture anchor repairs (1.8 ± 0.7 mm). There was no significant difference in the force required to cause the clinical failure of the repairs between the suture tape (35.1 ± 18.1 N) and suture anchor (24.5 ± 9.2 N) repairs. CONCLUSIONS: Index finger RCL repair with suture tape augmentation results in decreased deformation with repetitive motion compared with RCL repair alone. CLINICAL RELEVANCE: Suture tape augmentation may allow for early mobilization following index finger RCL repair by acting as a brace that protects the repaired ligament from deforming forces.

Bicortical suspensory button fixation yields greater ultimate load to failure over unicortical all-suture anchor fixation in distal biceps brachii tendon repair.

BACKGROUND: Various distal biceps tendon repair techniques exist, each with their own biomechanical profile. Recently, all-suture anchor fixation has recently become an intriguing option for distal biceps fixation, compared with the proven track record of the suspensory cortical button. In addition, intramedullary techniques have been utilized as a means to avoid complications such as nerve damage seen with extramedullary fixation. PURPOSE: The purpose of this study is to perform a comparative biomechanical analysis of 4 unique distal biceps tendon fixation methods: Unicortical/intramedullary all-suture anchor fixation (UIAS), Bicortical/extramedullary all-suture anchor fixation (BEAS), Unicortical/intramedullary suspensory button fixation (UISB), and Bicortical/extramedullary suspensory button fixation (BESB). STUDY DESIGN: Controlled Laboratory study. METHODS: 24 fresh-frozen cadaveric elbows were randomized into 4 groups providing data from 6 specimens, with each group undergoing a different repair technique. The specimens underwent 2 studies: Cyclic loading and Ultimate Load to failure (ULTF) testing. The repaired elbows were cycled 3000 times between 0 and 90 degrees of flexion, with displacement under cyclic loading at the repair site measured using a differential variable reductance transducer. ULTF test was performed with the elbow flexed at 90 degrees. The modes of failure were recorded. RESULTS: The mean cyclic displacements between the 4 groups were as follows: UIAS: 1.45 ± 1.04 mm; BEAS: 2.75 ± 1.32 mm; UISB: 1.45 ± .776 mm; BESB: 2.66 ± 1.18 mm (p= 0.077). Bicortical repairs displayed greater displacement after cyclic loading when compared with unicortical repairs regardless of anchor used (p= 0.007). The mean ULTF for each group was as follows: all-suture intramedullary: 200 N; all-suture extramedullary: 330 N; cortical-button intramedullary: 256 N; cortical-button extramedullary: 342 N). All-suture unicortical/intramedullary repair had a significantly lower ULTF (200 N) compared with cortical-button Bicortical/extramedullary repair (342 N) (p=0.043). CONCLUSION: Bicortical/extramedullary suspensory button fixation demonstrated a greater ultimate load to failure when compared with unicortical/intramedullary all-suture anchor fixation. These findings suggest that bicortical/extramedullary suspensory cortical button fixation is a biomechanically superior construct as compared to unicortical/intramedullary all-suture anchor fixation. However, there was no significant difference in ULTF between extra-medullary, Bicortical button or Bicortical, all-suture anchor fixation.

The Effects of Preoperative Epidural Steroid Injection on Pseudarthrosis Following Lumbar Fusion: A Retrospective Cohort Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The goal of this study is to evaluate the effects of preoperative lumbar epidural steroid injection on the rate of pseudarthrosis following lumbar spine fusion surgery. SUMMARY OF BACKGROUND DATA: Epidural corticosteroids help to reduce nerve root edema and suppress proinflammatory cytokines in patients with radiculopathy. Corticosteroids may inhibit bone formation and reduce bone matrix synthesis rates. Thus, there is concern that corticosteroids may reduce lumbar fusion capability, potentially resulting in increased rates of symptomatic pseudarthrosis. MATERIALS AND METHODS: We identified all patients who underwent 1-level or 2-level lumbar fusion surgery between 2018 and 2022. Patients were categorized into one of 3 groups: no preoperative epidural steroid injection (ESI) history (group 0), preoperative ESI within 90 days of surgery (group 1), or most recent ESI >90 days before surgery (group 2). The primary outcome of this study was pseudarthrosis. Binominal regression analyses were performed to determine the relationships between potential risk factors (sex, age, body mass index, smoking history, diabetes status, history of systemic steroid use, preoperative ESI, perioperative intravenous steroid administration, type of surgery, and postoperative ESI within 6 mo) and the development of postoperative pseudarthrosis. RESULTS: A total of 446 patients were included in this study. Of those, 106 patients (23.7%) did not have a preoperative ESI (group 0), 132 patients (29.5%) had an ESI within 90 days of surgery (group 1), and 208 patients (46.6%) had their most recent ESI >90 days before surgery (group 2). The overall incidence of pseudarthrosis following lumbar fusion was 8.7% (39 of 446). Although the incidence of pseudarthrosis following ESI at any time point was higher than in our control cohort (group 0), this difference was not statistically significant. CONCLUSIONS: This study found no increased risk of postoperative pseudarthrosis in patients who underwent 1-level or 2-level lumbar fusions after preoperative ESI. LEVEL OF EVIDENCE: Level III.

Lateral interbody fusion for adjacent segment disease: a narrative review.

Background and Objective: Adjacent segment disease (ASD) is a late complication of lumbar fusion characterized by persistent symptoms correlating to radiographic changes in the levels immediately above or below the prior fusion. Lateral interbody fusion (LIF) through a direct lateral approach is a minimally invasive and effective surgical treatment for ASD. Biomechanically, LIF for ASD provides significantly decreased motion in multiple planes. While hardware failure and injury to the lumbar plexus are potential complications, these risks may be outweighed by decreased blood loss, shorter operating room (OR) times, and possibly superior patient reported visual analog scale (VAS) scores compared to traditional posterior spinal fusion (PSF) alone. The purpose of this review is to summarize the history, uses, outcomes, and future directions of LIF for ASD. Methods: A review of national databases (PubMed and SCOPUS) was performed using literature from 1900 to 2022. Keywords included terms "LATERAL" and "LUMBAR" and "INTERBODY" and "FUSION" and "ADJACENT" and "SEGMENT" and "DISEASE". Studies that aimed to describe the biomechanical, clinical course and complications, radiological outcomes, biomechanical aspects, need for revision surgery, and/or patient reported outcomes of the XLIF/LIF technique were included. Key Content and Findings: This review includes a brief overview of the natural history of ASD and current approaches to address it. It then summarizes the main indications and utilization of LIF to address ASD, summarizing reported outcomes in regard to biomechanical, clinical, and radiographic outcomes. Conclusions: LIF has emerged as a minimally invasive and effective surgical treatment for ASD. This mini-review suggests that LIF provides a solid foundational biomechanical construct that has been paired with good patient-reported, clinical, and radiographic outcomes. While further research is required, current literature suggests that LIF for ASD results in fewer complications, decreased morbidity, and decreased need for subsequent surgery compared to other commonly utilized techniques.

Clinical and radiologic outcomes of posterior column extension, pedicle subtraction, and vertebral column resection osteotomies in adult chin on chest deformity: A systematic review.

Background: Chin-on-chest deformity is a rare and severely disabling condition characterized by kyphotic deformity in the cervicothoracic spine. To treat this deformity, various osteotomy techniques were described. Methods: A comprehensive literature search of biomedical databases including MEDLINE (via PubMed), Scopus (via Elsevier), Embase (via Elsevier), and Cochrane Library in English from 1/1/1990 to 3/31/2022 was conducted using a combination of text and Medical Subject Headings (MeSH). Results: The final analysis included 16 studies. All the studies were assigned a level of evidence of four. Except for two articles, all of the articles were non-comparative studies. A total of 288 patients were included in this review. Of the 288 patients, 107 underwent posterior column extension osteotomy (PCEO), 108 underwent pedicle subtraction osteotomy (PSO), and 33 underwent vertebral column resection osteotomy (VCRO). The most common osteotomy level in fifteen of the studies was C7/T1. The studies included in this review described several techniques for cervical sagittal balance correction. The range of preoperative and postoperative visual analogue scale (VAS) scores was 5.5-8.6 to 1.7-4.91, respectively. The range of preoperative and postoperative neck disability index (NDI) was 34.2-65.4 to 22.1-51.3, respectively. The most common complications were upper extremity paresthesia and hand numbness through the C8 dermatome distribution. Conclusions: Corrective osteotomies provide satisfactory results in patients with chin-on-chest deformity; however, the quality of the included studies limits the evidence.

ChatGPT as a Source of Patient Information for Lumbar Spinal Fusion and Laminectomy: A Comparative Analysis Against Google Web Search.

STUDY DESIGN: Retrospective Observational Study. OBJECTIVE: The objective of this study was to assess the utility of ChatGPT, an artificial intelligence chatbot, in providing patient information for lumbar spinal fusion and lumbar laminectomy in comparison with the Google search engine. SUMMARY OF BACKGROUND DATA: ChatGPT, an artificial intelligence chatbot with seemingly unlimited functionality, may present an alternative to a Google web search for patients seeking information about medical questions. With widespread misinformation and suboptimal quality of online health information, it is imperative to assess ChatGPT as a resource for this purpose. METHODS: The first 10 frequently asked questions (FAQs) related to the search terms "lumbar spinal fusion" and "lumbar laminectomy" were extracted from Google and ChatGPT. Responses to shared questions were compared regarding length and readability, using the Flesch Reading Ease score and Flesch-Kincaid Grade Level. Numerical FAQs from Google were replicated in ChatGPT. RESULTS: Two of 10 (20%) questions for both lumbar spinal fusion and lumbar laminectomy were asked similarly between ChatGPT and Google. Compared with Google, ChatGPT's responses were lengthier (340.0 vs. 159.3 words) and of lower readability (Flesch Reading Ease score: 34.0 vs. 58.2; Flesch-Kincaid grade level: 11.6 vs. 8.8). Subjectively, we evaluated these responses to be accurate and adequately nonspecific. Each response concluded with a recommendation to discuss further with a health care provider. Over half of the numerical questions from Google produced a varying or nonnumerical response in ChatGPT. CONCLUSIONS: FAQs and responses regarding lumbar spinal fusion and lumbar laminectomy were highly variable between Google and ChatGPT. While ChatGPT may be able to produce relatively accurate responses in select questions, its role remains as a supplement or starting point to a consultation with a physician, not as a replacement, and should be taken with caution until its functionality can be validated.

Modern Internet Search Analytics: Is There a Difference in What Patients are Searching Regarding the Operative and Nonoperative Management of Scoliosis?

STUDY DESIGN: Observational Study. OBJECTIVES: This study aimed to investigate the most searched types of questions and online resources implicated in the operative and nonoperative management of scoliosis. METHODS: Six terms related to operative and nonoperative scoliosis treatment were searched on Google's People Also Ask section on October 12, 2023. The Rothwell classification was used to sort questions into fact, policy, or value categories, and associated websites were classified by type. Fischer's exact tests compared question type and websites encountered between operative and nonoperative questions. Statistical significance was set at the .05 level. RESULTS: The most common questions concerning operative and nonoperative management were fact (53.4%) and value (35.5%) questions, respectively. The most common subcategory pertaining to operative and nonoperative questions were specific activities/restrictions (21.7%) and evaluation of treatment (33.3%), respectively. Questions on indications/management (13.2% vs 31.2%, P < .001) and evaluation of treatment (10.1% vs 33.3%, P < .001) were associated with nonoperative scoliosis management. Medical practice websites were the most common website to which questions concerning operative (31.9%) and nonoperative (51.4%) management were directed to. Operative questions were more likely to be directed to academic websites (21.7% vs 10.0%, P = .037) and less likely to be directed to medical practice websites (31.9% vs 51.4%, P = .007) than nonoperative questions. CONCLUSIONS: During scoliosis consultations, spine surgeons should emphasize the postoperative recovery process and efficacy of conservative treatment modalities for the operative and nonoperative management of scoliosis, respectively. Future research should assess the impact of website encounters on patients' decision-making.

Operative Time Associated With Increased Length of Stay After Single-level Cervical Disk Arthroplasty: An Analysis of 3681 Surgeries.

STUDY DESIGN: Level III evidence-retrospective cohort. OBJECTIVE: The purpose of this study was to (1) determine whether longer CDA operative time increases the risk of 30-day postoperative complications, (2) analyze the association between operative time and subsequent health care utilization, and (3) discharge disposition. BACKGROUND: Cervical disk arthroplasty (CDA) most commonly serves as an alternative to anterior cervical discectomy and fusion (ACDF) to treat cervical spine disease, however, with only 1600 CDAs performed annually relative to 132,000 ACDFs, it is a relatively novel procedure. METHODS: A retrospective query was performed identifying patients who underwent single-level CDA between January 2012 and December 2018 using a nationwide database. Differences in baseline patient demographics were identified through univariate analysis. Multivariate logistic regression was performed to identify associations between operative time (reference: 81-100 min), medical/surgical complications, and health care utilization. RESULTS: A total of 3681 cases were performed, with a mean patient age of 45.52 years and operative time of 107.72±49.6 minutes. Higher odds of length of stay were demonstrated starting with operative time category 101-120 minutes (odds ratio: 2.164, 95% CI: 1.247-3.754, P=0.006); however, not among discharge destination, 30-day unplanned readmission, or reoperation. Operative time <40 minutes was associated with 10.7x odds of nonhome discharge, while >240 minutes was associated with 4.4 times higher odds of LOS>2 days (P<0.01). Increased operative time was not associated with higher odds of wound complication/infection, pulmonary embolism, deep venous thrombosis, or urinary tract infections. CONCLUSIONS: Prolonged CDA operative time above the reference 81-100 minutes is independently associated with increased length of stay, but not other significant health care utilization parameters, including discharge disposition, readmission, or reoperation. There was no association between prolonged operative time and 30-day medical/surgical complications, including wound complications, infections, pulmonary embolism, or urinary tract infection.

Risk Factors for Readmission Following Surgical Decompression for Spinal Epidural Abscesses: An Analysis of 4595 Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The study aimed to (1) compare baseline demographics of patients undergoing surgery for SEA who were/were not readmitted; (2) identify risk factors for 90-day readmissions; and (3) quantify 90-day episode-of-care health care costs. BACKGROUND: Spinal epidural abscess (SEA), while rare, occurring ~2.5-5.1/10,000 admissions, may lead to permanent neurologic deficits and mortality. Definitive treatment often involves surgical intervention via decompression. METHODS: A search of the PearlDiver database from 2010 to 2021 for patients undergoing decompression for SEA identified 4595 patients. Cohorts were identified through the International Classification of Disease, Ninth Revision (ICD-9), ICD-10, and Current Procedural Terminology codes. Baseline demographics of patients who were/were not readmitted within 90 days following decompression were aggregated/compared, identifying factors associated with readmission. Using Bonferroni correction, a P-value<0.001 was considered statistically significant. RESULTS: Readmission within 90 days of surgical decompression occurred in 36.1% (1659/4595) of patients. While age/gender were not associated with readmission rate, alcohol use disorder, arrhythmia, chronic kidney disease, ischemic heart disease, and obesity were associated with readmission. Readmission risk factors included fluid/electrolyte abnormalities, obesity, paralysis, tobacco use, and pathologic weight loss (P<0.0001). Mean same-day total costs ($17,920 vs. $8204, P<0.001) and mean 90-day costs ($46,050 vs. $15,200, P<0.001) were significantly higher in the readmission group. CONCLUSION: A substantial proportion of patients (36.1%) are readmitted within 90 days following surgical decompression for SEA. The top 5 risk factors in descending order are fluid/electrolyte abnormalities, pathologic weight loss, tobacco use, pre-existing paralysis, and obesity. This study highlights areas for perioperative medical optimization that may reduce health care utilization.

GPT-4 as a Source of Patient Information for Anterior Cervical Discectomy and Fusion: A Comparative Analysis Against Google Web Search.

STUDY DESIGN: Comparative study. OBJECTIVES: This study aims to compare Google and GPT-4 in terms of (1) question types, (2) response readability, (3) source quality, and (4) numerical response accuracy for the top 10 most frequently asked questions (FAQs) about anterior cervical discectomy and fusion (ACDF). METHODS: "Anterior cervical discectomy and fusion" was searched on Google and GPT-4 on December 18, 2023. Top 10 FAQs were classified according to the Rothwell system. Source quality was evaluated using JAMA benchmark criteria and readability was assessed using Flesch Reading Ease and Flesch-Kincaid grade level. Differences in JAMA scores, Flesch-Kincaid grade level, Flesch Reading Ease, and word count between platforms were analyzed using Student's t-tests. Statistical significance was set at the .05 level. RESULTS: Frequently asked questions from Google were varied, while GPT-4 focused on technical details and indications/management. GPT-4 showed a higher Flesch-Kincaid grade level (12.96 vs 9.28, P = .003), lower Flesch Reading Ease score (37.07 vs 54.85, P = .005), and higher JAMA scores for source quality (3.333 vs 1.800, P = .016). Numerically, 6 out of 10 responses varied between platforms, with GPT-4 providing broader recovery timelines for ACDF. CONCLUSIONS: This study demonstrates GPT-4's ability to elevate patient education by providing high-quality, diverse information tailored to those with advanced literacy levels. As AI technology evolves, refining these tools for accuracy and user-friendliness remains crucial, catering to patients' varying literacy levels and information needs in spine surgery.

Type A Thymoma with Spinal and Cranial Metastases: A Case Report.

Introduction: While metastases of malignant thymomas have been shown, type A thymomas are often treated as benign. Type A thymomas often have excellent response to treatment, low recurrence rate, and a small malignant potential. To date, there have been no reports of type A thymomas with spinal metastases. Case Report: A 66-year-old female with a type A thymoma metastatic to the T7 and T8 vertebral bodies and brain, with associated pathologic burst fracture, collapse of T7, and significant focal kyphosis . The patient underwent successful T7-T8 posterior corpectomy and T4-T11 posterior spinal fusion. At 2 years of follow-up, she was ambulating without assistive devices and completed spinal radiation and initial chemotherapy. Conclusion: Metastatic type A thymoma is a rare phenomenon. While traditionally thought to have low recurrence rates and overall excellent survival rates, our case suggests that the biologic malignant potential of a type A thymoma may not be fully understood.

Multilevel Customized 3D-Printed Titanium Alloy Interbody Cages used to Treat Congenital Scoliosis: A Case Report.

Introduction: Customized, patient-specific interbody cages have been used in the treatment of spinal neoplasia, degenerative disease, infection, congenital anomalies, and trauma. However, to date, their use has been limited to a single spinal level, and the utility of customized spinal implants in multiple spinal levels remains unclear. In addition, limited studies exist that compare outcomes following fusion and decompression surgery using customized implants to traditional, standard implants. Case Report: We present two cases. Case 1 consists of a multilevel deformity surgery from L3-S1 ALIF and T10-Pelvis PSF in a patient with a congenital scoliosis (CS) using customized implants on multiple spinal levels. We compare Case 1 to Case 2, in which a patient underwent a lumbar decompression and fusion for CS using standard titanium implants. While the patient in Case 1 reported improved back pain and independent ambulation at 1-year post-operative and required no revision surgery, the patient in Case 2 required revision surgery 2 years post-operative due to pseudoarthrosis. Conclusion: CS with right wedge hemivertebrae may be treated with customized implants on multiple spinal levels, and customized implants may provide benefit standard implants.

Reverse Shoulder Arthroplasty Patients Younger Than 60 Years Old Exhibit Lower Clinically Significant Single Assessment Numeric Evaluation (SANE) Scores Compared to Older Patients.

INTRODUCTION: The incidence of reverse shoulder arthroplasty (RTSA) in the United States has increased. Patients under 60 years old with failed rotator cuff repairs or degenerative joint disease with glenoid deformity may be candidates for RTSA and contribute to this increase. The single assessment numeric evaluation (SANE) score is a reliable post-operative scoring technique when compared with other post-operative measures. This study aimed to compare the effect of age on the likelihood of reaching clinically significant SANE scores following RTSA. METHODS: A multicenter retrospective review was performed with a consecutive series of RTSA from December 2015 to September 2021. Patients were stratified into groups based on their age at the time of operation: (1) less than 60 years old, (2) 60-69 years old, (3) 70-79 years old, and (3) greater than 80 years old. The proportions of patients in all cohorts reaching and surpassing clinically significant thresholds at each visit were determined. Likelihood ratios were determined for each age cohort to compare the likelihood of reaching clinically significant SANE scores. RESULTS: A total of 292 of 885 (33%) patients had completed survey data over two years and were included in the study. The 70-79-year-old group was 3.152 (p=.035) times more likely to achieve minimal clinically important difference (MCID) and 2.125 (p=.048) times more likely to achieve patient-acceptable symptomatic state (PASS) compared with patients <60 years old. The cohort who was 80+ years old was also 4.867 (p=.045) times more likely to achieve MCID compared to the <60-year-old cohort. The <60 cohort had the lowest proportion of all patient cohorts achieving MCID. CONCLUSION: A lower proportion of patients younger than 60 years old undergoing RTSA achieved clinically significant post-operative SANE scores. The 70-79-year-old age group was more likely to reach MCID and PASS, and the patients who were 80+ years old were more likely to reach MCID compared to patients younger than 60 years old.

Early Clinical Outcomes of the Prone Transpsoas Lumbar Interbody Fusion Technique.

BACKGROUND: The prone transpsoas (PTP) approach for lateral lumbar interbody fusion (LLIF) is a relatively novel technique. Currently, little is known about its associated complications and early patient-reported outcomes. The aim of this study was to investigate the effect of LLIF performed via the PTP approach on sagittal radiographic parameters, patient-reported outcome measures (PROMs), and rates of complications. METHODS: A retrospective review was performed of 82 consecutive patients who underwent LLIF via a PTP technique. Lumbar lordosis (LL), segmental lordosis (SL), anterior disc height (ADH), and posterior disc height (PDH) were measured on preoperative, initial postoperative, and 3-month postoperative radiographs. PROMs including the Oswestry Disability Index (ODI); the visual analog scale (VAS); and pain portions of the EQ5D, VAS back, and VAS leg ratings were collected at the preoperative and subsequent postoperative visits. Length of hospital stay and postoperative complications related to the procedure were recorded. RESULTS: Significant improvements were seen at the initial (4.5° ± 8.6°, P < 0.001) and 3-month (4.4° ± 7.2°, P < 0.001) postoperative periods for LL, as well as SL (6.8° ± 4.8°, P < 0.001; 6.7° ± 4.4°, P < 0.001), ADH (8.0 mm ± 3.6, P < 0.001; 7.4 mm ± 3.6, P < 0.001), and PDH (3.3 mm ± 2.4, P < 0.001; 3.1 mm ± 2.5, P < 0.001). Significant improvements were seen at 3 months postoperatively for ODI (P < 0.001), EQ5D pain (P = 0.016), VAS leg (P < 0.001), and VAS back (P < 0.001). The average length of stay was 2.7 ± 4.5 days. The most common complications were ipsilateral thigh pain/numbness (45.1%), ipsilateral hip flexor weakness (39.0%), and contralateral thigh pain/numbness (14.6%). CONCLUSIONS: While early PROMs and correction of sagittal radiographic parameters show promising results for the PTP approach for LLIF, it is not without risks. CLINICAL RELEVANCE: PTP interbody fusion is an emerging technique that allows for simultaneous access to the anterior and posterior columns of the lumbar spine. This early case series demonstrates significant improvement in functional outcomes and lumbar lordosis with a safety profile comparable to other well-established techniques.

Plate vs. intramedullary screw fixation of chevron olecranon osteotomies: a biomechanical study.

Background: Intra-articular distal humerus fractures frequently require olecranon osteotomies for adequate exposure, but fixation of olecranon osteotomies is associated with high rates of hardware-related complications requiring subsequent reoperation for removal. Intramedullary screw fixation is an attractive option to attempt to minimize hardware prominence. The purpose of this biomechanical study is to directly compare intramedullary screw fixation (IMSF) with plate fixation (PF) of chevron olecranon osteotomies. It was hypothesized that PF would be biomechanically superior to IMSF. Methods: Chevron olecranon osteotomies of 12 matched pairs of fresh-frozen human cadaveric elbows were repaired with either precontoured proximal ulna locking plates or cannulated screws with a washer. Displacement and amplitude of displacement at the dorsal and medial aspects of the osteotomies under cyclic loading conditions were measured. Finally, the specimens were loaded to failure. Results: The IMSF group had significantly greater medial displacement (P = .034) and dorsal amplitude (P = .029) than the PF group. Medial displacement was negatively correlated with bone mineral density in the IMSF group (r = -0.66, P = .035) but not in the PF group (r = .160, P = .64). Mean load to failure between groups, however, was not statistically significant (P = .183). Conclusions: While there was no statistically significant difference in the load to failure between the two groups, IMSF repair resulted in significantly greater displacement of the medial osteotomy site during cyclic loading and greater amplitude of displacement dorsally with loading force. Decreased bone mineral density was associated with an increased displacement of the medial repair site. These results suggest that IMSF of olecranon osteotomies may result in increased fracture site displacement when compared to PF; this displacement may be greater in patients with poor bone quality.

Location of distal pronator quadratus repair in distal radius fractures: A cadaveric biomechanical study.

BACKGROUND: We aimed to biomechanically evaluate the distal pronator quadratus and compare two locations of distal transection on the strength of the subsequent repair. METHODS: Eighteen fresh-frozen cadaveric specimens were dissected to the pronator quadratus muscle. Specimens were randomly allocated for transection of the pronator quadratus at the myotendinous junction (red group) or parallel to the myotendinous junction at the midsection of the distal tendinous zone (white group). For both groups, repair of the muscle was performed using two figure-of-8 sutures. The radius and ulna were positioned in 90° of wrist extension. The proximal muscular pronator quadratus was fixed in a cryo-clamp. Load-to-failure testing of the repair was performed at 1 mm/s with maximum amount of force applied to the pronator quadratus recorded for each specimen. FINDINGS: The pronator quadratus had a mean width, height, and area of 31.41 ± 5.74 mm, 53.79 ± 7.46 mm, and 1604.27 ± 429.20 mm2 respectively. The pronator quadratus distal tendinous zone had a mean width, height, and area of 29.71 ± 5.83 mm, 12.22 ± 2.79 mm, 282.94 ± 148.30 mm2 respectively. There was no significant difference between the two groups for pronator quadratus height, width, total area, or tendinous zone height, width, or total area. The average load to failure for the white group was significantly higher than that of the red group (29.46 ± 4.24 N vs. 13.78 N ± 6.66 N). INTERPRETATION: Incision and repair of the pronator quadratus in the distal tendinous region is stronger than incision and repair at the red myotendinous junction of the distal PQ.