Cemented vs Cementless Robotic-Assisted Total Knee Arthroplasty Yield Similar Short-Term Clinical Outcomes.

Background: In primary total knee arthroplasty (TKA), there is ongoing controversy about optimal fixation (cemented vs cementless). Cemented TKA remains the gold standard, with the largest body of long-term evidence available to support it. However, cementless TKA implants are gaining popularity due to potential biomechanical advantages and a growing body of literature supporting survivorship. Due to paucity of literature investigating fixation methods in robotic-assisted TKA (Ra-TKA), we aim to compare clinical outcomes of cementless Ra-TKA with those of cemented Ra-TKA. Methods: This is a retrospective cohort study of patients who underwent Ra-TKA by 19 surgeons comparing results of cases using cementless vs cemented fixation. We observed short-term complications, emergency room visits, and readmissions. We collected patient-reported outcomes measurement information system and knee injury and osteoarthritis outcome scores preoperatively and 12 weeks after surgery. Results: A total of 582 TKA cases were included: 335 cementless and 247 cemented. The patients in the cementless group were younger and had a higher body mass index. The cemented group had a higher rate of return to the operating room, with manipulation under anesthesia for stiffness being the most common indication in both groups. There were no statistically significant differences in 30-day readmissions, 90-day emergency room visits, or patient-reported outcomes. Conclusions: Our retrospective study demonstrated higher return to operating room in the cemented group vs the cementless group. We reported no differences in any other short-term outcomes between the cementless and cemented Ra-TKA. Our data support efficacy and safety of cementless Ra-TKA at 3-month follow-up.

Evaluation of Timing of Antimicrobial Surgical Prophylaxis on Rates of Surgical Site Infections.

Background: Surgical site infections (SSIs) are common healthcare-associated infections, and national guidelines recommend that antimicrobial prophylaxis (AP) be administered 60 min prior to incision. However, there are limited data regarding the "most optimal" time for administration within the 60-min window. Patients and Methods: This was a multicenter, retrospective study of adult (≥18-year-old) patients that underwent an abdominal hysterectomy, colorectal surgery, or craniotomy and received AP within 60 min of incision. Incidence of SSI was compared between patients who received AP 0-30 versus 31-60 min of incision. In addition, a predefined subgroup analysis evaluated incidence of SSI for 15-min intervals within the 60-min timeframe. Results: Of the 277 patients included in the primary analysis, 233 (84.1%) and 44 (15.9%) received AP 0-30 min and 31-60 min prior to incision, respectively. SSIs were documented in 6.0% (14/233) versus 4.5% (2/44) of patients in the primary analysis (p = 0.703). In the secondary analysis, 137 (49.5%), 95 (34.3%), 34 (12.3%), and 11 (4.0%) patients received AP 0-15, 16-30, 31-45, and 46-60 min prior to incision, respectively. There was no difference in incidence of SSIs among the 15-min intervals (4.4% vs. 8.4% vs. 2.9% vs. 9.1%, p = 0.487). Of the 16 patients in this study that incurred a SSI, 5 patients had positive cultures, of which 3 contained bacteria that proved to be resistant to the antibiotic used for AP. Conclusions: The results of our analysis support current national guidelines. Future investigation of different intervals (e.g., AP 15-45 min prior to incision) may be beneficial on the basis of pharmacokinetics of routinely prescribed AP.

Residual OXPHOS is required to drive primary and metastatic lung tumours in an orthotopic breast cancer model.

Background: Fast adaptation of glycolytic and mitochondrial energy pathways to changes in the tumour microenvironment is a hallmark of cancer. Purely glycolytic ρ0 tumour cells do not form primary tumours unless they acquire healthy mitochondria from their micro-environment. Here we explored the effects of severely compromised respiration on the metastatic capability of 4T1 mouse breast cancer cells. Methods: 4T1 cell lines with different levels of respiratory capacity were generated; the Seahorse extracellular flux analyser was used to evaluate oxygen consumption rates, fluorescent confocal microscopy to assess the number of SYBR gold-stained mitochondrial DNA nucleoids, and the presence of the ATP5B protein in the cytoplasm and fluorescent in situ nuclear hybridization was used to establish ploidy. MinION nanopore RNA sequence analysis was used to compare mitochondrial DNA transcription between cell lines. Orthotopic injection was used to determine the ability of cells to metastasize to the lungs of female Balb/c mice. Results: OXPHOS-deficient ATP5B-KO3.1 cells did not generate primary tumours. Severely OXPHOS compromised ρ0D5 cells generated both primary tumours and lung metastases. Cells generated from lung metastasis of both OXPHOS-competent and OXPHOS-compromised cells formed primary tumours but no metastases when re-injected into mice. OXPHOS-compromised cells significantly increased their mtDNA content, but this did not result in increased OXPHOS capacity, which was not due to decreased mtDNA transcription. Gene set enrichment analysis suggests that certain cells derived from lung metastases downregulate their epithelial-to-mesenchymal related pathways. Conclusion: In summary, OXPHOS is required for tumorigenesis in this orthotopic mouse breast cancer model but even very low levels of OXPHOS are sufficient to generate both primary tumours and lung metastases.

Bilateral tibial fractures associated with powered exoskeleton use in complete spinal cord injury - a case report & literature review.

INTRODUCTION: Powered robotic exoskeleton (PRE) physiotherapy programmes are a relatively novel frontier which allow patients with reduced mobility to engage in supported walking. Research is ongoing regarding their utility, risks, and benefits. This article describes the case of two fractures occurring in one patient using a PRE. CASE: We report the case of a 54 year old man who sustained bilateral tibial fractures while using a PRE, on a background of T10 AIS A SCI. The initial session was discontinued due to acute severe bilateral knee swelling after approximately 15 min. The patient attended their local hospital the following day, where radiographs demonstrated bilateral proximal tibial fractures. The patient was treated with manipulation under anaesthetic and long-leg casting for five weeks, at which point he was stepped down to hinged knee braces which were weaned gradually while he remained non-weight bearing for 12 weeks. The patient was investigated with DEXA scan and was diagnosed with osteoporosis. He was liaised with rheumatology services and bone protection was initiated. Fracture healing was achieved and weight-bearing precautions were discontinued, however this period of immobilisation led to significant spasticity. The patient was discharged from orthopaedic services, with ongoing rehabilitation and physiotherapy follow-up. CONCLUSION: PRE assisted physiotherapy programmes are a promising concept in terms of rehabilitation and independence, however they are not without risk and it is important that both providers and patients are aware of this. Furthermore, SCI patients are at increased risk for osteoporosis and should be monitored and considered for bone protection.

Comparing return to play protocols after sports-related concussion among international sporting organisations.

BACKGROUND: Return to play (RTP) protocols are an important part of recovery management following a sport-related concussion (SRC) and can prevent athletes from returning to competition too early and thereby avoid prolonged recovery times. To assist sporting organizations in the development of RTP guidelines, the Concussion in Sports Group (CISG) provides scientific-based recommendations for the management of SRC in its consensus statement on concussion in sport. OBJECTIVES: This study investigates commonalities and differences among current RTP protocols of international sporting organizations and examines the implementation of the most recent CISG recommendations. METHODS: Concussion guidelines and medical rules of 12 international sporting organizations from contact, collision and combat sports were accessed via the organizations websites and compared regarding the management of SRC and the RTP decision. RESULTS: Only six of the included organizations developed and published their own concussion guidelines, which included an RTP protocol on their website. The number of steps until RTP was similar across the different protocols. Each protocol required at least one medical examination before clearing an athlete to RTP. A high variation among organizations was found for initial resting period after injury, the implementation of sport-specific training drills and the time needed to complete the protocol before returning to competition. At the date of this study (9 September 2023), none of the accessible RTP protocols were updated to include the latest version of the CISG consensus statement. CONCLUSION: To improve the safety of athletes after a head injury, sporting organizations should develop sport-specific guidelines according to the latest CISG consensus statement, and this should be updated regularly. Implementation is especially important in combat sports, where there is a high incidence of head injury. Thus, there is a requirement for the most up-to-date concussion management protocols in these sports.

Effectiveness of contact tracing on networks with cliques.

Contact tracing, the practice of isolating individuals who have been in contact with infected individuals, is an effective and practical way of containing disease spread. Here we show that this strategy is particularly effective in the presence of social groups: Once the disease enters a group, contact tracing not only cuts direct infection paths but can also pre-emptively quarantine group members such that it will cut indirect spreading routes. We show these results by using a deliberately stylized model that allows us to isolate the effect of contact tracing within the clique structure of the network where the contagion is spreading. This will enable us to derive mean-field approximations and epidemic thresholds to demonstrate the efficiency of contact tracing in social networks with small groups. This analysis shows that contact tracing in networks with groups is more efficient the larger the groups are. We show how these results can be understood by approximating the combination of disease spreading and contact tracing with a complex contagion process where every failed infection attempt will lead to a lower infection probability in the following attempts. Our results illustrate how contact tracing in real-world settings can be more efficient than predicted by models that treat the system as fully mixed or the network structure as locally treelike.

Intradiscal vacuum phenomenon matches lumbar spine degeneration patterns in an ageing population.

PURPOSE: Intra-Discal Vacuum phenomenon (IDVP) is well-recognised, yet poorly visualised and poorly understood radiological finding in disc degeneration, particularly with regard to its role in spinal alignment. CT analysis of the lumbar spine in an aging population aims to identify patterns associated with IDVP including lumbopelvic morphology and associated spinal diagnoses. METHODS: An analysis was performed of an over-60s population sample of 2020 unrelated abdominal CT scans, without acute spinal presentations. Spinal analysis included sagittal lumbopelvic reconstructions to assess for IDVP and pelvic incidence (PI). Subjects with degenerative pathologies, including previous vertebral fractures, auto-fusion, transitional vertebrae, and listhesis, were also selected out and analysed separately. RESULTS: The prevalence of lumbar spine IDVP was 50.3% (955/1898) and increased with age (125 exclusions). This increased in severity towards the lumbosacral junction (L1L2 8.3%, L2L3 10.9%, L3L4 11.5%, L4L5 23.9%, and L5S1 46.3%). A lower PI yielded a higher incidence of IDVP, particularly at L5S1 (p < 0.01). A total of 292 patients had IDVP with additional degenerative pathologies, which were more likely to occur at the level of isthmic spondylolisthesis, adjacent to a previous fracture or suprajacent to a lumbosacral transitional vertebra (p < 0.05). CONCLUSIONS: This study identified the prevalence and severity of IDVP in an aging population. Sagittal patterns that influence the pattern of IVDP, such as pelvic incidence and degenerative pathologies, provide novel insights into the function of aging spines.

Natural History of Intradiscal Vacuum Phenomenon and its Role in Advanced Disc Degeneration.

STUDY DESIGN: Observational serial computed tomography (CT) analysis of the lumbar spine in a normal-aging population. OBJECTIVE: To assess the natural history of the intradiscal vacuum phenomenon (IDVP) and its role in disc degeneration. BACKGROUND: The natural history of disc degeneration is well described but our understanding of the end stage of pathogenesis remains incomplete. Magnetic resonance imaging loses accuracy with advanced degeneration, becoming hyporesonant and indistinct. Cadaveric specimens display adaptive changes in the disc with loss of the hydrostatic capacity of the nucleus, increased intradiscal clefts, and endplate impermeability. IDVP is associated with advanced disc degeneration and CT is the optimal modality to visualize this, yet these insights remain unreported. PATIENTS AND METHODS: Patients only included historic CT abdomen scans of those over 60 years of age without acute or relevant spinal pathology, with a diagnosis of at least one level with IDVP on the original CT scan, and all of whom had a similar scan >7 years later. A history of clinically significant back pain was also recorded. RESULTS: CT scans included 360 levels in 29 males and 31 females (mean: 68.9 y), displaying 82 levels of IDVP, with a second scan included after a mean of 10.3 years. Most levels displayed the same level of severity (persisted, 45) compared with where some progressed (26), regressed (8), and fused (3; P < 0.01). There was also an increased incidence, 37/60 (62%) of developing IDVP at another level. Disc heights were reduced with increased severity of IDVP. A record of back pain was evident in 31/60 patients, which was not significantly worse in those with worsening severity or additional level involvement over the study period. CONCLUSION: As disc degeneration advances, the associated IDVP persists in most cases, displaying a plateauing of severity over long periods, but rarely with progression to autofusion.

Disparities in Liver Transplantation for Nonalcoholic Steatohepatitis in Women.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is the fastest-growing indication for liver transplantation (LT). Sex disparities among patients with cirrhosis on the LT waitlist are well known. We wanted to understand these disparities further in women with end-stage liver disease patients listed for NASH cirrhosis in a contemporary cohort. METHODS: We used data from the Scientific Registry of Transplant Recipients to assess sex racial, and ethnic differences in NASH patients listed for LT. Adults transplanted from August 1997 to June 2021 were included. Inferential statistics were used to evaluate differences with univariate and multivariate comparisons, including competitive risk analysis. RESULTS: During the study time period, we evaluated 12 844 LT for NASH cirrhosis. Women were transplanted at a lower rate (46.5% versus 53.5%; P  < 0.001) and higher model for end-stage liver disease (MELD) (23.8 versus 22.6; P < 0.001) than men. Non-White women were transplanted at a higher MELD (26.1 versus 23.1; P  < 0.001) than White women and non-White male patients (26.1 versus 24.8; P  < 0.001). Graft and patient survivals were significantly different ( P  < 0.001) between non-White women and White women and men (White and non-White). CONCLUSIONS: Evaluation of LT candidates in the United States demonstrates women with NASH cirrhosis have a higher MELD than men at LT. Additional disparities exist among non-White women with NASH as they have higher MELD and creatinine at LT compared with White women. After LT, non-White women have worse graft and patient survival compared with men or White women. These data indicate that non-White women with NASH are the most vulnerable on the LT waitlist.