Consensus statements and guideline for the diagnosis and management of plantar fasciitis in Singapore.

Introduction: Plantar fasciitis (PF) is a common cause of heel pain among the general population. The lack of standard practice guideline in Singapore presents challenges in education and clinical practice for this painful condition. These consensus statements and guideline were developed to streamline and improve the management of PF, covering key aspects such as diagnosis, investigations, risk factors, treatment modalities, monitoring and return to work/play. Method: A multidisciplinary expert panel consisting of 6 sports physicians, 2 orthopaedic surgeons, 2 podiatrists and 1 physiotherapist from SingHealth Duke-NUS Sport & Exercise Medicine Centre (SDSC) was convened based on their clinical and academic experience with PF. The Grading of Recommen-dations, Assessment, Development and Evaluations (GRADE) approach was used to evaluate the quality of the evidence and subsequently prepare a set of clinical recommen-dations pertaining to the manage-ment of PF. A modified Delphi process was used to reach consensus. Results: Eighteen consensus statements were developed to cover key components of PF management, from initial diagnosis to treatment modalities and finally, clinical progression. They were subsequently consolidated under a proposed treatment pathway guideline for PF. Conclusion: The SDSC consensus statements and guideline provide concise recommendations for the management of PF in Singapore.

Biomechanical consequences of proximal screw placement in minimally invasive surgery for hallux valgus correction.

Hallux valgus is one of the most common surgically corrected forefoot deformities. Studies evaluating clinical outcomes of minimally invasive chevron and akin (MICA) procedure have shown shorter operation time, faster recovery, and smaller scars compared to the open approach. Previous biomechanical cadaveric studies have largely focused on the open approach with minimal on MICA. To our knowledge, no studies have compared different proximal screw placements in MICA which can either be three-point fixation or intramedullary. This study aims to compare the biomechanical properties of fixation between these two techniques in MICA. Six matched pairs of human fresh frozen cadaveric feet were randomized to either three-point fixation or intramedullary groups. Both procedures were performed by a single fellowship-trained orthopaedic foot and ankle surgeon. Using a material testing machine, each specimen underwent 1000 cycles of plantar-to-dorsal uniaxial loads from 0 to 31 N in cantilever configuration while monitoring bending stiffness and distal fragment dorsal angulation. They were then subjected to load until failure at a compression rate of 10 mm/min. Specimens from both groups tolerated the walking fatigue test. Mean bending stiffness of three-point fixation was 84% higher than intramedullary constructs (P=0.002). Mean dorsal angulation of intramedullary was thrice that of three-point fixation constructs (P=0.008). Mean load to failure of three-point fixation was 30% higher than intramedullary constructs (P=0.001). Three-point fixation provide superior biomechanical stability compared to intramedullary proximal screw placement. The surgical technique using three-point proximal screw fixation can offer robust fixation and lead to better clinical outcomes. LEVEL OF CLINICAL EVIDENCE: 5.

Winograd Wedge Resection Matrixectomy versus Partial Nail Avulsion with Chemical Cautery: A Tertiary Institution's Clinical Outcomes and Proposed Triaging Protocol.

BACKGROUND: Onychocryptosis, or ingrown toenail, is a common condition affecting patients of varying age groups, although usually, younger patients are affected. METHODS: We compared two techniques used in our institution: Winograd wedge resection with matrixectomy (WG-M) versus partial nail avulsion with phenolization of the nail matrix (PNA-P). RESULTS: Primary outcomes of interest were presence of nail regrowth and patient satisfaction postoperatively. Secondary outcomes were postoperative pain (within the first 2 weeks and after 2 weeks), postoperative inflammation, and healing time. A total of 65 patients were included in this study: 44 patients (19 female and 25 male patients), with a mean age of 45.7 years (range, 16-83 years) underwent WG-M in the orthopedic surgery department, whereas a total of 21 patients (10 female and 11 male patients), with a mean age of 44.5 years (range, 13 to 75 years) underwent PNA-P in the podiatry department. In patients who underwent WG-M, there was one case of regrowth (2.3%) compared with no regrowth cases (0%) in the PNA-P group. There was no significant difference in regrowth rate between the two procedures (P = .494). The satisfaction rate was high for both procedures: 100% patients in the WG-M group rated themselves better than before surgery, compared with 95.7% in the PNA-P group. CONCLUSIONS: From our study, we conclude that both techniques (WG-M and PNA-P) are able to achieve similar clinical outcomes, with the PNA-P procedure being less invasive and less resource intensive, and also achieving a shorter healing time.

Genetic interrogation for sequence and copy number variants in systemic lupus erythematosus.

Early-onset systemic lupus erythematosus presents with a more severe disease and is associated with a greater genetic burden, especially in patients from Black, Asian or Hispanic ancestries. Next-generation sequencing techniques, notably whole exome sequencing, have been extensively used in genomic interrogation studies to identify causal disease variants that are increasingly implicated in the development of autoimmunity. This Review discusses the known casual variants of polygenic and monogenic systemic lupus erythematosus and its implications under certain genetic disparities while suggesting an age-based sequencing strategy to aid in clinical diagnostics and patient management for improved patient care.

Crosstalk between CD64+MHCII+ macrophages and CD4+ T cells drives joint pathology during chikungunya.

Communications between immune cells are essential to ensure appropriate coordination of their activities. Here, we observed the infiltration of activated macrophages into the joint-footpads of chikungunya virus (CHIKV)-infected animals. Large numbers of CD64+MHCII+ and CD64+MHCII- macrophages were present in the joint-footpad, preceded by the recruitment of their CD11b+Ly6C+ inflammatory monocyte precursors. Recruitment and differentiation of these myeloid subsets were dependent on CD4+ T cells and GM-CSF. Transcriptomic and gene ontology analyses of CD64+MHCII+ and CD64+MHCII- macrophages revealed 89 differentially expressed genes, including genes involved in T cell proliferation and differentiation pathways. Depletion of phagocytes, including CD64+MHCII+ macrophages, from CHIKV-infected mice reduced disease pathology, demonstrating that these cells play a pro-inflammatory role in CHIKV infection. Together, these results highlight the synergistic dynamics of immune cell crosstalk in driving CHIKV immunopathogenesis. This study provides new insights in the disease mechanism and offers opportunities for development of novel anti-CHIKV therapeutics.

Sex as a Predictor of Response to Immunotherapy in Advanced Cutaneous Squamous Cell Carcinoma.

Approximately 3-5% of patients with cutaneous squamous cell carcinoma (CSCC) develop advanced disease, accounting for roughly 1% of all cancer deaths in Australia. Immunotherapy has demonstrated significant clinical benefit in advanced CSCC in several key phase II studies; however, there are limited data for patients treated outside of clinical trials. This is particularly relevant in advanced CSCC, which is most often seen in elderly patients with significant comorbidities. Thus, we aim to describe our experience with immunotherapy in a cohort of patients with advanced CSCC in Australia. We retrospectively reviewed all advanced CSCC patients treated with immunotherapy within the Illawarra and Shoalhaven Local Health District. Among the 51 patients treated with immunotherapy, there was an objective response rate (ORR) of 53% and disease control rate (DCR) of 67%. Our most significant predictor of response was sex, with male patients more likely to have better responses compared to female patients (DCR 85% vs. 41%, p < 0.0001), as well as improved progression-free survival (HR 4.6, 95%CI 1.9-10.8, p = 0.0007) and overall survival (HR 3.0, 95%CI 1.3-7.1, p = 0.006). Differential expression analysis of 770 immune-related genes demonstrated an impaired CD8 T-cell response in female patients. Our observed ORR of 53% is similar to that described in current literature with durable responses seen in the majority of patients.

Glomus tumour: an institutional experience of 31 cases.

BACKGROUND: Glomus tumour is an uncommon soft tissue tumour which commonly occurs in the distal extremities, particularly the subungual region of the finger. Due to its rarity, there is a paucity of literature concerning glomus tumour. Therefore, this paper aims to report a case series based on our institution's experience. METHODS: A retrospective cross sectional study was performed in a single tertiary institution in Singapore. All patients diagnosed with glomus tumour confirmed on histology from January 2019 to October 2022 were included in the study. Patient demographics and clinical information (presenting signs and symptoms, tumour parameters and presence of recurrence) were retrieved from existing medical records. RESULTS: A total of 31 cases of glomus tumour were diagnosed from January 2019 to October 2022, and the relevant demographics and clinical presentation were reported. Majority of glomus tumours occurred in the finger (61.3%). Pain was present in almost all the cases (96.8%), while a lump was visible in less than half (48.4%). An average of 44.0 months elapsed before patients were properly diagnosed and treated. There were no cases of recurrence despite involved margins in three cases. CONCLUSION: Glomus tumour can be easily missed if clinicians do not have an index of suspicion for it, resulting in delayed treatment. Once diagnosed, glomus tumour can be treated with complete excision with good outcomes.

Third dose of BNT162b2 improves immune response in liver transplant recipients to ancestral strain but not Omicron BA.1 and XBB.

Vaccine immunogenicity in transplant recipients can be impacted by the immunosuppressive (IS) regimens they receive. While BNT162b2 vaccination has been shown to induce an immune response in liver transplant recipients (LTRs), it remains unclear how different IS regimens may affect vaccine immunogenicity after a third BNT162b2 dose in LTRs, which is especially important given the emergence of the Omicron sublineages of SARS-CoV-2. A total of 95 LTRs receiving single and multiple IS regimens were recruited and offered three doses of BNT162b2 during the study period. Blood samples were collected on days 0, 90, and 180 after the first BNT162b2 dose. At each time point, levels of anti-spike antibodies, their neutralizing activity, and specific memory B and T cell responses were assessed. LTRs receiving single IS regimens showed an absence of poor immunogenicity, while LTRs receiving multiple IS regimens showed lower levels of spike-specific antibodies and immunological memory compared to vaccinated healthy controls after two doses of BNT162b2. With a third dose of BNT162b2, spike-specific humoral, memory B, and T cell responses in LTR significantly improved against the ancestral strain of SARS-CoV-2 and were comparable to those seen in healthy controls who received only two doses of BNT162b2. However, LTRs receiving multiple IS regimens still showed poor antibody responses against Omicron sublineages BA.1 and XBB. A third dose of BNT162b2 may be beneficial in boosting antibody, memory B, and T cell responses in LTRs receiving multiple IS regimens, especially against the ancestral Wuhan strain of SARS-CoV-2. However, due to the continued vulnerability of LTRs to presently circulating Omicron variants, antiviral treatments such as medications need to be considered to prevent severe COVID-19 in these individuals.

Two-Year Clinical and Radiologic Outcomes Following Surgical Treatment of Insertional Achilles Tendinopathy Using a Central Tendon-Splitting Approach.

BACKGROUND: If conservative treatment of insertional Achilles tendinopathy (IAT) fails, surgery is often considered. Various surgical approaches have been used including the central Achilles tendon splitting approach. This study aimed to report the 2-year clinical and radiologic outcomes after surgical treatment of IAT with a central tendon-splitting approach. METHODS: Seventy-five cases of IAT treated surgically via the open central tendon-splitting approach were analyzed. Clinical outcomes included the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, visual analog scale (VAS), 36-Item Short Form Health Survey (SF-36) physical (PCS) and mental (MCS) component summary scores, all measured at baseline and 6 and 24 months postoperatively. Radiologic parameters measured included the Fowler-Philip angle (FPA) and parallel pitch lines (PPL). RESULTS: Three patients had clinically significant wound issues but healed completely by 3 weeks. Mean AOFAS score improved from 45.63 preoperatively to 94.71 at 24 months. Mean VAS score improved from 6.73 preoperatively to 0.55, mean SF-36 PCS from 35.98 to 48.74, and mean SF-36 MCS from 53.04 to 55.43 at 24 months. Satisfaction at 2 years was 94.3%. Mean FPA decreased from 62.0 degrees preoperatively to 34.0 degrees postoperatively. PPL was positive in 82.7% (62 of 75) of cases preoperatively, decreasing to 1.3% (1 of 75) postoperatively. Increasing age and higher preoperative VAS and SF-36 MCS scores were significantly associated with improvements in postoperative AOFAS, SF-36 PCS, and MCS scores. CONCLUSION: Surgical treatment of IAT via the central tendon-splitting approach achieved substantial improvements in all patient-reported outcome measures measured. These excellent clinical outcomes continued to show improvement 2 years postoperatively. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Prolonged inflammation in patients hospitalized for coronavirus disease 2019 (COVID-19) resolves 2 years after infection.

Long-term complications from coronavirus disease 2019 (COVID-19) are concerning, as survivors can develop subclinical multiorgan dysfunction. It is unknown if such complications are due to prolonged inflammation, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination may reduce sequela. We conducted a prospective longitudinal study on hospitalized patients over 24 months. Clinical symptoms were collected by self-reporting during follow-up, along with blood samples for quantification of inflammatory markers and immune cell frequencies. All patients were given one dose of mRNA vaccine at 12-16 months. Their immune profiles at 12 and 24 months were compared. Approximately 37% and 39% of our patients reported post-COVID-19 symptoms at 12 and 24 months, respectively. The proportion of symptomatic patients with more than one symptom decreased from 69% at 12 months to 56% at 24 months. Longitudinal cytokine profiling revealed a cluster of individuals with persistently high inflammatory cytokine levels 12 months after infection. Patients with prolonged inflammation showed elevated terminally differentiated memory T cells in their blood; 54% had symptoms at 12 months. The majority of inflammatory markers and dysregulated immune cells in vaccinated patients recovered to a healthy baseline at 24 months, even though symptoms persisted. Post-COVID-19 symptoms can linger for 2 years after the initial infection and are associated with prolonged inflammation. Prolonged inflammation in hospitalized patients resolves after 2 years. We define a set of analytes associated with persistent inflammation and presence of symptoms, which could be useful biomarkers for identifying and monitoring high-risk survivors.

Validity and Reliability of the European Foot and Ankle Society (EFAS) Score in Patients With Hallux Valgus in Singapore.

The European Foot and Ankle Society score is a popular tool for monitoring treatment outcomes of foot or ankle conditions. However, few studies have assessed its psychometric properties in patients with hallux valgus. We aimed to validate the European Foot and Ankle Society score in patients with hallux valgus in Singapore. This is a cohort study of 121 patients with operatively managed hallux valgus from a tertiary referral hospital, evaluated preoperatively and at 6 months postoperatively with the primary endpoint of restoring patients to premorbid status. Internal consistency was assessed via Cronbach's alpha. Construct validity was assessed through 7 a priori hypotheses by correlating the European Foot and Ankle Society score with other patient-reported outcomes measures. Structural validity was assessed via Confirmatory Factor Analysis, whereby a good fit was indicated when Comparative Fit Index >0.95, Tucker-Lewis Index >0.95, Root Mean Square Error of Approximation <0.06, and Standardized Root Mean Residuals <0.08. Among our subjects, the European Foot and Ankle Society score demonstrated reliability, reflected by a good internal consistency (Cronbach's alpha = 0.773). Six out of the 7 a priori hypotheses were fulfilled, indicating both convergent and divergent construct validity. Structural validity was confirmed with our European Foot and Ankle Society score model which showed good fit for a 1-factor structure (Confirmatory Factor Analysis = 0.998, Tucker-Lewis Index = 0.996, Root Mean Square Error of Approximation = 0.025 [90% CI: 0-0.111], Standardized Root Mean Residuals = 0.027). In conclusion, the European Foot and Ankle Society score was validated for monitoring treatment outcomes of patients with hallux valgus in Singapore.

Hepatectomy and pancreatectomy: how we could do it.

Visible patient software provides surgeons and trainees with the opportunity to construct accurate three dimensional models of patients liver and pancreas which reflect tumour location and unique anatomical features. These can be used for operative planning, patient discussions, operative rehearsal and teaching as well as pre and postoperative briefings.

Efficient recall of SARS-CoV-2 variant-reactive B cells and T responses in the elderly upon heterologous mRNA vaccines as boosters.

Waning antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the emergence of variants of concern highlight the need for booster vaccinations. This is particularly important for the elderly population, who are at a higher risk of developing severe coronavirus disease 2019 (COVID-19) disease. While studies have shown increased antibody responses following booster vaccination, understanding the changes in T and B cell compartments induced by a third vaccine dose remains limited. We analyzed the humoral and cellular responses in subjects who received either a homologous messenger RNA(mRNA) booster vaccine (BNT162b2 + BNT162b2 + BNT162b2; ''BBB") or a heterologous mRNA booster vaccine (BNT162b2 + BNT162b2 + mRNA-1273; ''BBM") at Day 0 (prebooster), Day 7, and Day 28 (postbooster). Compared with BBB, elderly individuals (≥60 years old) who received the BBM vaccination regimen display higher levels of neutralizing antibodies against the Wuhan and Delta strains along with a higher boost in immunoglobulin G memory B cells, particularly against the Omicron variant. Circulating T helper type 1(Th1), Th2, Th17, and T follicular helper responses were also increased in elderly individuals given the BBM regimen. While mRNA vaccines increase antibody, T cell, and B cell responses against SARS-CoV-2 1 month after receiving the third dose booster, the efficacy of the booster vaccine strategies may vary depending on age group and regimen combination.

Lower vaccine-acquired immunity in the elderly population following two-dose BNT162b2 vaccination is alleviated by a third vaccine dose.

Understanding the impact of age on vaccinations is essential for the design and delivery of vaccines against SARS-CoV-2. Here, we present findings from a comprehensive analysis of multiple compartments of the memory immune response in 312 individuals vaccinated with the BNT162b2 SARS-CoV-2 mRNA vaccine. Two vaccine doses induce high antibody and T cell responses in most individuals. However, antibody recognition of the Spike protein of the Delta and Omicron variants is less efficient than that of the ancestral Wuhan strain. Age-stratified analyses identify a group of low antibody responders where individuals ≥60 years are overrepresented. Waning of the antibody and cellular responses is observed in 30% of the vaccinees after 6 months. However, age does not influence the waning of these responses. Taken together, while individuals ≥60 years old take longer to acquire vaccine-induced immunity, they develop more sustained acquired immunity at 6 months post-vaccination. A third dose strongly boosts the low antibody responses in the older individuals against the ancestral Wuhan strain, Delta and Omicron variants.

Hallux valgus with second metatarsalgia: Is second metatarsal Weil osteotomy necessary?

BACKGROUND: The role of concomitant Weil osteotomy to address second toe metatarsalgia during hallux valgus correction is unclear. We aimed to critically analyse outcomes of an additional Weil osteotomy versus isolated Scarf osteotomy.in the management of hallux valgus and second metatarsalgia. METHODS: Patients with second toe metatarsalgia who underwent first metatarsal Scarf osteotomy for hallux valgus were enrolled retrospectively. Demographics, radiographic measurements and functional outcomes were assessed at baseline, 6-months and 2-years postoperatively. Between-group significance was established with Fisher exact test, Chi-square or Mann-Whitney U test. Within-group changes from baseline were assessed with paired t-test and Wilcoxon signed-rank test. RESULTS: 48 feet (34 isolated Scarf, 14 concomitant Weil osteotomy) were included. Both cohorts demonstrated significant improvements across all measures of functional outcome. However, patients with additional Weil osteotomy reported poorer short-term outcomes. CONCLUSION: Superiority of additional Weil osteotomy versus isolated Scarf osteotomy in addressing second toe metatarsalgia or improving functional outcomes was not demonstrated.

Radiofrequency Plantar Fascia Coblation With and Without Gastrocnemius Recession in the Management of Recalcitrant Plantar Fasciitis.

BACKGROUND: Plantar fasciitis is the most common cause of plantar heel pain. Although most are self-limiting, recalcitrant conditions can be debilitating, significantly reducing patient's quality of life. A myriad of surgical procedures are available for the treatment of recalcitrant plantar fasciitis (RPF) with little consensus on best practice. This purpose of this study was to assess the efficacy of radiofrequency coblation with and without gastrocnemius release on the surgical management of RPF. METHODS: Between June 2013 and June 2019, a total of 128 patients with RPF and tight gastrocnemius were treated surgically. Presence of tight gastrocnemius was assessed clinically by a positive Silfverskiold test. Group A (n = 73) consisted of patients who underwent radiofrequency coblation alone; group B (n = 55) consisted of patients who underwent radiofrequency coblation and endoscopic gastrocnemius recession. The primary outcome measure was visual analog scale (VAS) score. Secondary outcome measures included (1) American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score; (2) physical (PCS) and mental component summaries (MCS) of the 36-Item Short Form Health Survey; (3) overall assessment of improvement, expectation fulfilment, and satisfaction; and (4) complication rates. RESULTS: Both groups reported significant improvement in VAS, AOFAS, and PCS scores postoperatively at 6 and 24 months. Group B (radiofrequency coblation with gastrocnemius recession) was associated with better VAS at both 6 months (3.0 ± 2.9 vs 1.7 ± 2.6, P < .05) and 24 months postoperatively (1.9 ± 3.1 vs 0.8 ± 2.0, P < .05) compared with group A (radiofrequency coblation without gastrocnemius recession). At 24 months postoperatively, no differences were found in AOFAS, PCS, MCS scores, expectation fulfilment, or overall satisfaction. No wound complications were reported in either group. One patient (group B) has persistent symptoms consistent with tarsal tunnel syndrome. CONCLUSION: In this retrospective cohort comparative study, treatment of RPF with radiofrequency coblation alone was associated with slightly inferior results than radiofrequency coblation combined with endoscopic gastrocnemius recession in terms of pain relief without an increase in complication rates. However, at 2 years, we did not find a significant difference in other measures of outcome. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Association of Elevated Body Mass Index and Outcomes of Arthroscopic Treatment for Osteochondral Lesions of the Talus.

Background: Osteochondral lesions of the talus (OLTs) are a common condition found in patients with chronic ankle pain after previous ankle sprains. Surgical management is indicated after conservative management has failed. Hypothesis/Purpose: This study evaluates the influence of body mass index (BMI) on the early clinical outcomes of arthroscopic debridement and microfracture of OLTs. Methods: A total of 252 patients with symptomatic OLTs who failed conservative management underwent arthroscopic debridement and microfracture of OLTs over the affected ankle between 2007 and 2017. Patients from this cohort were divided into 2 groups based on BMI: the normal BMI group (NB Group) (BMI 18.5-25.0) and overweight and obese BMI group (OB Group) (BMI ≥25). Visual analogue scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, and the physical and mental component summaries of the 36-Item Short-Form Health Survey (PCS and MCS, respectively) were prospectively collected from the cohort during their standard postoperative outpatient follow-up. Results: The NB Group (n=105) and OB Group (n=147) were well matched demographically. The operative duration was significantly shorter for the NB Group compared to the OB Group. Patients from both groups had significant improvements in VAS, AOFAS, and PCS scores postoperatively at 6 and 24 months after surgery (P < .05). Between both groups, patients had comparable VAS, AOFAS, and PCS scores at preoperation, 6 months postoperation, and 24 months postoperation (P > .05). However, MCS in the OB Group was lower at 24 months postoperatively compared with the NB Group (P < .05). The OB Group reported better satisfaction scores (82.4% vs 72.6%, P < .05), and a greater proportion had their expectations met (88.2% vs 77.9%, P < .05). Conclusion: A BMI ≥25 was not associated with worse postoperative pain and functional outcomes, but rather was found to be associated with greater satisfaction and fulfillment. However, patients with BMI ≥25 required longer procedure duration and had poorer MCS scores at 24 months after surgery.Level of Evidence: Level III, retrospective cohort study.

Validity and Reliability of the American Orthopaedic Foot and Ankle Society Score for the English-Literate Singapore Population With Hallux Valgus.

BACKGROUND: This study aimed to evaluate the reliability and validity of the American Orthopaedic Foot and Ankle Society Metatarsophalangeal-Interphalangeal (AOFAS MTP-IP) score in patients with hallux valgus in Singapore. METHOD: A total of 121 English-literate patients with hallux valgus identified between October 2017 and May 2020 were analyzed. Reliability was assessed via Cronbach α. Construct validity was evaluated through 20 a priori hypotheses by correlating the AOFAS MTP-IP score for hallux and lesser toes with other patient-reported outcome measures (PROMs). Standardized response means (SRMs) were calculated to evaluate responsiveness at 6 months postoperative. Structural validity was evaluated via confirmatory factor analysis (CFA) whereby a good fit was indicated when comparative fit index (CFI) is >0.95, Tucker-Lewis index (TLI) is >0.95 and standardized root mean residual (SRMR) is <0.08. RESULTS: The AOFAS MTP-IP score demonstrated reliability with a Cronbach α of 0.837. Convergent construct validity was confirmed when all a priori hypotheses were fulfilled. Structural validity was established with our AOFAS MTP-IP score model that displayed good fit for a 1-factor structure (CFI = 0.988, TLI = 0.960, SRMR = 0.034). Responsiveness of the AOFAS MTP-IP score for hallux was demonstrated by an SRM score of 1.28. CONCLUSION: The AOFAS MTP-IP score displayed adequate reliability and validity among English-literate patients in Singapore with an operatively managed hallux valgus. LEVEL OF EVIDENCE: Level III: Retrospective cohort study.

Decreased memory B cell frequencies in COVID-19 delta variant vaccine breakthrough infection.

The SARS-CoV-2 Delta (B.1.617.2) variant is capable of infecting vaccinated persons. An open question remains as to whether deficiencies in specific vaccine-elicited immune responses result in susceptibility to vaccine breakthrough infection. We investigated 55 vaccine breakthrough infection cases (mostly Delta) in Singapore, comparing them against 86 vaccinated close contacts who did not contract infection. Vaccine breakthrough cases showed lower memory B cell frequencies against SARS-CoV-2 receptor-binding domain (RBD). Compared to plasma antibodies, antibodies secreted by memory B cells retained a higher fraction of neutralizing properties against the Delta variant. Inflammatory cytokines including IL-1ß and TNF were lower in vaccine breakthrough infections than primary infection of similar disease severity, underscoring the usefulness of vaccination in preventing inflammation. This report highlights the importance of memory B cells against vaccine breakthrough and suggests that lower memory B cell levels may be a correlate of risk for Delta vaccine breakthrough infection.

Malaria abrogates O'nyong-nyong virus pathologies by restricting virus infection in nonimmune cells.

O'nyongnyong virus (ONNV) is a re-emerging alphavirus previously known to be transmitted by main malaria vectors, thus suggesting the possibility of coinfections with arboviruses in co-endemic areas. However, the pathological outcomes of such infections remain unknown. Using murine coinfection models, we demonstrated that a preexisting blood-stage Plasmodium infection suppresses ONNV-induced pathologies. We further showed that suppression of viremia and virus dissemination are dependent on Plasmodium-induced IFNγ and are associated with reduced infection of CD45- cells at the site of virus inoculation. We further proved that treatment with IFNγ or plasma samples from Plasmodium vivax-infected patients containing IFNγ are able to restrict ONNV infection in human fibroblast, synoviocyte, skeletal muscle, and endothelial cell lines. Mechanistically, the role of IFNγ in restricting ONNV infection was confirmed in in vitro infection assays through the generation of an IFNγ receptor 1 α chain (IFNγR1)-deficient cell line.