Validating the capture rate of revisions by the New Zealand ACL Registry: An analysis of all-cause reoperation following primary ACL reconstruction.

PURPOSE: To validate the New Zealand Anterior Cruciate Ligament (ACL) Registry's capture rate of revisions by cross-referencing Registry data with reoperations data recorded by the Accident Compensation Corporation (ACC) and identify risk factors for all-cause reoperation. METHODS: Primary ACL reconstructions performed between April 2014 and September 2019 were individually matched on a record-by-record basis between the two databases. The ACC database was used to identify patients who underwent a reoperation with manual review of operation notes to identify whether a revision or other procedure was performed. This was combined with the number of revisions separately recorded in the New Zealand ACL Registry, which was used as the denominator value to calculate the Registry's capture rate of revisions. Patient and surgical data recorded in the Registry were analysed to identify independent predictors for all-cause reoperation. RESULTS: A total of 8046 primary ACL reconstructions were matched between the New Zealand ACL Registry and the ACC databases. The reoperation rate was 8.9% (n = 715) at a mean follow-up of 2.5 years. Meniscal-related procedures were the most common reoperation (n = 299, 3.7%), followed by revision ACL reconstruction (n = 219, 2.7%), arthrofibrosis (n = 185, 2.3%), cartilage (n = 56, 0.7%) and implants (n = 32, 0.4%). The New Zealand ACL Registry captured 96% of revisions. Younger age (hazard ratio [HR] > 1.4, p < 0.001), earlier surgery (HR > 1.3, p = 0.05), concurrent meniscal repair (medial meniscus HR = 1.9, p < 0.001 and lateral meniscus HR = 1.3, p = 0.022) and hamstring tendon autografts (HR = 1.4, p = 0.001) were associated with a higher risk of reoperation. CONCLUSION: The New Zealand ACL Registry captured 96% of revisions. Risk factors for all-cause reoperation included younger age, earlier surgery, meniscal repair and hamstring tendon autografts. LEVEL OF EVIDENCE: Level III.

Risk factors for reoperation for arthrofibrosis following primary anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study is to identify the rate and risk factors for a reoperation for arthrofibrosis following primary anterior cruciate ligament (ACL) reconstruction. METHODS: Prospective data recorded in the New Zealand ACL Registry were cross-referenced with data from the Accident Compensation Corporation (ACC). Primary ACL reconstructions performed between April 2014 and May 2021 were analysed. The ACC database was used to identify patients who underwent a reoperation for a diagnosis of arthrofibrosis. Multivariable survival analysis was performed to compute adjusted hazard ratios (aHR) and 95% confidence intervals. RESULTS: A total of 12,296 primary ACL reconstructions were analysed, of which 230 underwent a reoperation for arthrofibrosis (1.9%) at a mean follow-up of 3.6 years. A higher risk of arthrofibrosis was observed in females (aHR = 1.76, p = 0.001), patients with a history of previous knee surgery (aHR = 1.82, p = 0.04) and when a transtibial drilling technique was used (aHR = 1.53, p = 0.03). ACL reconstruction >6 months after injury had the lowest rate of arthrofibrosis (1.3%, aHR = 0.45, p = 0.01). There was no difference in risk between early surgery within 6 weeks versus delayed surgery between 6 weeks and 6 months after injury (2.9% versus 2.1%, aHR = 0.78, not significant). CONCLUSION: Female sex, previous knee surgery and a transtibial drilling technique increased the risk of reoperation for arthrofibrosis. Early surgery within 6 weeks of injury was not associated with an increased risk when compared with surgery between 6 weeks and 6 months after injury. LEVEL OF EVIDENCE: Level III.

Clinical and functional outcomes of TKA after HTO or UKA: a New Zealand Joint Registry Study.

INTRODUCTION: Surgical options for patients with unicompartmental knee osteoarthritis include high tibial osteotomy (HTO) or unicompartmental knee arthroplasty (UKA). When managing younger patients with a higher chance of further surgery, the outcome of any subsequent conversion to total knee arthroplasty (TKA) also needs to be considered. The aim of this study was to compare implant survivorship and patient-reported outcomes for patients undergoing TKA after previous HTO or UKA, with comparisons for age, gender and comorbidities. METHODS: Revision risk and 6-month Oxford Knee Scores (OKS) from the New Zealand Joint Registry were compared for patients who underwent TKA after HTO (HTO-TKA; n = 1556) or UKA (UKA-TKA; n = 965) between 1999 and 2019, with a comparison group of primary TKA (n = 110,948). Mean follow-up was 8.2 years. RESULTS: Adjusted revision risk was similar for HTO-TKA and UKA-TKA groups (hazard ratio (HR) 1.04, p = 0.84); and risk for both groups were higher than primary TKA (HTO-TKA HR 1.45, p = 0.002; UKA-TKA HR 1.51, p = 0.01). Overall adjusted mean OKS at 6 months for HTO-TKA (36.2) was similar to primary TKA (36.8, p = 0.23); and both were higher than UKA-TKA (34.2, p < 0.001). For the youngest patient group (< 55 years), revision rates of UKA-TKA were two-fold higher than HTO-TKA (2.8 vs. 1.3 per 100 component yrs, p < 0.03). HTO-TKA had better OKS (37.5 vs. 34.1, p < 0.0001) for males. Mean OKS for UKA-TKA was lower than HTO-TKA for patients with ASA 1-2 (35.6 vs. 37.5, p < 0.01). CONCLUSION: The findings from this study suggest that revision rate following TKA after HTO and UKA are similar. However, TKA after HTO have superior functional outcomes compared with TKA after UKA and are comparable to functional outcomes post primary TKA. The results support the use of HTO for young, male and less co-morbid patients.

Previous arthroscopy does not decrease survivorship or functional outcomes for unicompartmental knee arthroplasty patients.

INTRODUCTION: Arthroscopic procedures for osteoarthritis (OA), in particular arthroscopic meniscectomy, have poorer long-term clinical outcomes compared to those managed non-operatively. In addition, previous arthroscopy is associated with worse outcomes following subsequent total knee arthroplasty (TKA), however there is limited data on the impact on subsequent unicompartmental knee arthroplasty (UKA) outcomes. The aim of the study is to investigate whether patients who had arthroscopy prior to UKA have differences in survivorship or functional outcomes compared to those with no prior arthroscopy. METHODS: All patients who received either a primary medial or lateral UKA at four large tertiary hospitals were included (n = 2,272). Patient data (age, sex, ethnicity, body mass index (BMI), American Society of Anesthesiologists (ASA) status and surgical data) was recorded following systematic review of all clinical notes and radiographs. Differences between survival curves were analysed using log-rank curves. Differences between categorical data was compared using Fisher's exact or Chi-squared tests, and differences between continuous variables were compared using t-tests. RESULTS: There was no difference between the survival curves for UKA patients with previous arthroscopy compared to those with no previous arthroscopy (10 years: 91% UKA with previous arthroscopy vs. 92% no previous arthroscopy; 15 years: 78% previous arthroscopy vs. 86% no previous arthroscopy; p = 0.50). Oxford Knee Score (OKS) was comparable between patients who had previous arthroscopy and those who had no previous arthroscopy at 6 months (38.8 vs. 39.3, p = 0.45), 5 years (42.0 vs. 40.4, p = 0.11) and 10 years (40.8 vs. 40.2, p = 0.71). DISCUSSION: In this large patient cohort with comprehensive review of clinical data and outcomes, we found that prior arthroscopy did not affect survivorship or functional outcomes of UKA patients.

Research-ready data: the C-Surv data model.

Research-ready data (data curated to a defined standard) increase scientific opportunity and rigour by integrating the data environment. The development of research platforms has highlighted the value of research-ready data, particularly for multi-cohort analyses. Following stakeholder consultation, a standard data model (C-Surv) optimised for data discovery, was developed using data from 5 population and clinical cohort studies. The model uses a four-tier nested structure based on 18 data themes selected according to user behaviour or technology. Standard variable naming conventions are applied to uniquely identify variables within the context of longitudinal studies. The data model was used to develop a harmonised dataset for 11 cohorts. This dataset populated the Cohort Explorer data discovery tool for assessing the feasibility of an analysis prior to making a data access request. Data preparation times were compared between cohort specific data models and C-Surv.It was concluded that adopting a common data model as a data standard for the discovery and analysis of research cohort data offers multiple benefits.

Evaluating the harmonisation potential of diverse cohort datasets.

Data discovery, the ability to find datasets relevant to an analysis, increases scientific opportunity, improves rigour and accelerates activity. Rapid growth in the depth, breadth, quantity and availability of data provides unprecedented opportunities and challenges for data discovery. A potential tool for increasing the efficiency of data discovery, particularly across multiple datasets is data harmonisation.A set of 124 variables, identified as being of broad interest to neurodegeneration, were harmonised using the C-Surv data model. Harmonisation strategies used were simple calibration, algorithmic transformation and standardisation to the Z-distribution. Widely used data conventions, optimised for inclusiveness rather than aetiological precision, were used as harmonisation rules. The harmonisation scheme was applied to data from four diverse population cohorts.Of the 120 variables that were found in the datasets, correspondence between the harmonised data schema and cohort-specific data models was complete or close for 111 (93%). For the remainder, harmonisation was possible with a marginal a loss of granularity.Although harmonisation is not an exact science, sufficient comparability across datasets was achieved to enable data discovery with relatively little loss of informativeness. This provides a basis for further work extending harmonisation to a larger variable list, applying the harmonisation to further datasets, and incentivising the development of data discovery tools.

Discordant imaging: adrenal vein sampling in almost half of patients with primary aldosteronism and a unilateral adrenal adenoma.

BACKGROUND: Primary hyperaldosteronism (PHA) is an underdiagnosed cause of secondary hypertension, with an increased risk of cardiovascular and renal complications compared with those with essential hypertension alone. Distinguishing between unilateral and bilateral aldosterone secretion is important as management differs. Adrenal vein sampling (AVS) is the gold standard for determining lateralisation. Current international guidelines suggest AVS may be omitted in those aged <35 years with PHA and a unilateral adrenal adenoma on imaging. AIM: To characterise all patients referred for AVS at Waitemata District Health Board (WDHB), review the success rate of AVS and compare concordance of AVS with imaging. METHODS: All patients who underwent AVS in WDHB from January 2015 to September 2020 were retrospectively assessed. Clinical records, laboratory data and radiological findings were reviewed. RESULTS: Ninety-six patients underwent AVS, with four excluded as private records were unable to be obtained. Of the 92 patients included, age ranged from 22 to 79 years. AVS was successful on first attempt in 89 (96.7%) patients. AVS and imaging findings were concordant in 62.2% of patients. One (14.3%) of seven aged <35 years had discordant results, and 16 (47%) of 34 patients with a unilateral adenoma on imaging had discordant results to AVS. CONCLUSIONS: AVS at WDHB is successful on first attempt in most patients. AVS is essential in the management of PHA for those deemed to be surgical candidates, regardless of age.

Does Immediate Long-Span Nerve Allograft Reconstruction Affect the Incidence of Chronic Postsurgical and Neuropathic Pain in the Reconstructed Mandible Following Resection for Benign and Malignant Disease.

BACKGROUND: Peripheral nerve injury can lead to chronic postsurgical pain (CPSP) and neuropathic pain following major surgery. PURPOSE: Determine in patients undergoing ablative mandibular operations with transection of the trigeminal nerve: do those who undergo immediate repair, when compared to those whose nerves are not repaired, have a decreased or increased risk for CPSP or post-traumatic trigeminal neuropathic pain (PTTNp)? STUDY DESIGN, SETTING, SAMPLE: A multisite, retrospective cohort of patients who underwent resection of the mandible for benign or malignant disease with either no repair or immediate repair of the intentionally transected trigeminal nerve with a long-span nerve allograft were analyzed for the presence or absence of CPSP and PTTNp at 6 months. PREDICTOR VARIABLE: The primary predictor was the immediate repair or no repair of the trigeminal nerve. MAIN OUTCOME VARIABLE: The primary outcome was the presence or absence of CPSP and PTTNp at 6 months postsurgery. COVARIATES: There were 13 covariate variables, including age, sex, ethnicity, nerve injury, type of PTTNp, malignant or benign pathology and subtypes of each, use of radiation or chemotherapy, treatment of transected nerve end, longest follow-up time, pain scale, and onset of pain. ANALYSES: Two-tailed Student's t test and Welch's t test were performed on mean scores and post hoc logistics and linear regression modeling were performed when indicated. The confidence level for statistical significance was P value <.05. RESULTS: There were 103 and 94 subjects in the immediate and no-repair groups, respectively. The incidence of CPSP in the no-repair group was 22.3% and PTTNp was 2.12%, while there was 3.8% CPSP and 0% PTTNp in the repair group, which was statistically significant (P = <.001). Logistic regression modeling showed a statistically significant inverse relationship between the immediate repair and the incidence of CPSP/PTTNp with an odds ratio of 0.43, 95% confidence interval 0.18 to 1.01, P = .05. Greater age, malignant pathology, and chemo/radiation treatments were covariates found more frequently in the no repair group. CONCLUSION AND RELEVANCE: Immediate repair of an intentionally transected trigeminal nerve with a long-span nerve allograft during resection of the mandible for both benign and malignant disease appears to reduce CPSP and possibly eliminate the development of PTTNp.

Robotic-arm assisted unicompartmental knee arthroplasty system has a learning curve of 11 cases and increased operating time.

PURPOSE: UKA has higher revision risk, particularly for lower volume surgeons. While robotic-arm assisted systems allow for increased accuracy, introduction of new systems has been associated with learning curves. The aim of this study was to determine the learning curve of a UKA robotic-arm assisted system. The hypothesis was that this may affect operative times, patient outcomes, limb alignment, and component placement. METHODS: Between 2017 and 2021, five surgeons performed 152 consecutive robotic-arm assisted primary medial UKA, and measurements of interest were recorded. Patient outcomes were measured with Oxford Knee Score, EuroQol-5D, and Forgotten Joint Score at 6 weeks, 1 year, and 2 years. Surgeons were grouped into 'low' and 'high' usage groups based on total UKA (manual and robotic) performed per year. RESULTS: A learning curve of 11 cases was found with operative time (p < 0.01), femoral rotation (p = 0.02), and insert sizing (p = 0.03), which highlighted areas that require care during the learning phase. Despite decreased 6-week EQ-5D-5L VAS in the proficiency group (77 cf. 85, p < 0.01), no difference was found with implant survival (98.2%) between phases (p = 0.15), or between 'high' and 'low' usage surgeons (p = 0.23) at 36 months. This suggested that the learning curve did not lead to early adverse effects in this patient cohort. CONCLUSION: Introduction of a UKA robotic-arm assisted system showed learning curves for operative times and insert sizing but not for implant survival at early follow-up. The short learning curve regardless of UKA usage indicated that robotic-arm assisted UKA may be particularly useful for low-usage surgeons. LEVEL OF EVIDENCE: Level III, Retrospective cohort study.

Early manipulation under anaesthesia for stiffness following total knee arthroplasty is associated with a greater gain in knee flexion.

PURPOSE: This study aimed to identify the risk factors for manipulation under anaesthesia (MUA) following total knee arthroplasty (TKA) and whether performing an 'early' MUA within 3 months leads to a greater improvement in range of motion. METHODS: Primary TKAs performed between 2013 and 2018 at three tertiary New Zealand hospitals were reviewed with a minimum follow-up of 1 year. Clinical details of patients who underwent MUA were reviewed to identify the knee flexion angle prior to and following MUA. Multivariate analysis identified the risk factors for undergoing MUA and compared flexion angles between 'early' (< 3 months) and 'late' MUA (> 3 months). RESULTS: A total of 7386 primary TKAs were analysed in which 131 underwent an MUA (1.8%). Patients aged < 65 years were two times more likely to undergo MUA compared to patients aged ≥ 65 years (2.5 versus 1.3%, p < 0.001; adjusted HR = 2.1, p < 0.001). There was no difference in the final flexion angle post-MUA between early and late MUA (104.7° versus 104.1°, p = 0.819). However, patients who underwent early MUA had poorer pre-MUA flexion (72.3° versus 79.6°, p = 0.012), and subsequently had a greater overall gain in flexion compared to those who underwent late MUA (mean gain 33.1° versus 24.3°, p < 0.001). CONCLUSION: Younger age was the only patient risk factor for MUA. Patients who underwent early MUA had similar post-MUA flexion, but had poorer pre-MUA flexion compared to those who underwent late MUA. Subsequently, a greater overall gain in flexion was achieved in those who underwent early MUA. LEVEL OF EVIDENCE: III.

Meniscal repair failure following concurrent primary anterior cruciate ligament reconstruction: results from the New Zealand ACL Registry.

PURPOSE: This study aimed to identify the risk factors for meniscal repair failure following concurrent primary anterior cruciate ligament (ACL) reconstruction. METHODS: Prospective data recorded by the New Zealand ACL Registry and the Accident Compensation Corporation were reviewed. Meniscal repairs performed during concurrent primary ACL reconstruction were included. Repair failure was defined as a subsequent reoperation involving meniscectomy of the repaired meniscus. Multivariate survival analysis was performed to identify the risk factors for failure. RESULTS: A total of 3,024 meniscal repairs were analysed with an overall failure rate of 6.6% (n = 201) at a mean follow-up of 2.9 years (SD 1.5). The risk of medial meniscal repair failure was higher with hamstring tendon autografts (adjusted HR [aHR] = 2.20, 95% CI 1.36-3.56, p = 0.001), patients aged 21-30 years (aHR = 1.60, 95% CI 1.30-2.48, p = 0.037) and in patients with cartilage injury in the medial compartment (aHR = 1.75, 95% CI 1.23-2.48, p = 0.002). The risk of lateral meniscal repair failure was higher in patients aged ≤ 20 years (aHR = 2.79, 95% CI 1.17-6.67, p = 0.021), when the procedure was performed by a low case volume surgeon (aHR = 1.84, 95% CI 1.08-3.13, p = 0.026) and when a transtibial technique was used to drill the femoral graft tunnel (aHR = 2.30, 95% CI 1.03-5.15, p = 0.042). CONCLUSION: The use of a hamstring tendon autograft, younger age and the presence of medial compartment cartilage injury are risk factors for medial meniscal repair failure, whereas younger age, low surgeon volume and a transtibial drilling technique are risk factors for lateral meniscal repair failure. LEVEL OF EVIDENCE: Level II.

Better post-operative outcomes at 1-year follow-up are associated with lower levels of pre-operative synovitis and higher levels of IL-6 and VEGFA in unicompartmental knee arthroplasty patients.

PURPOSE: Osteoarthritis (OA) is associated with inflammation, and residual inflammation may influence outcomes following knee arthroplasty. This may be more relevant for patients undergoing unicompartmental knee arthroplasty (UKA) due to larger remaining areas of native tissue. This study aimed to: (1) characterise inflammatory profiles for medial UKA patients and (2) investigate whether inflammation markers are associated with post-operative outcomes. METHODS: This prospective, observational study has national ethics approval. Bloods, synovial fluid, tibial plateaus and synovium were collected from medial UKA patients in between 1 January 2021 and 31 December 2021. Cytokine and chemokine concentrations in serum and synovial fluid (SF) were measured with multiplexed assays. Disease severity of cartilage and synovium was assessed using validated histological scores. Post-operative outcomes were measured with Oxford Knee Score (OKS), Forgotten Joint Score (FJS-12) and pain scores. RESULTS: The study included 35 patients. SF VEGFA was negatively correlated with pre-operative pain at rest (r - 0.5, p = 0.007), and FJS-12 at six-week (r 0.44, p = 0.02), six-month (r 0.61, p < 0.01) and one-year follow-up (r 0.63, p = 0.03). Serum and SF IL-6 were positively correlated with OKS at early follow-up (serum 6 weeks, r 0.39, p = 0.03; 6 months, r 0.48, p < 0.01; SF 6 weeks, r 0.35, p = 0.04). At six weeks, increased synovitis was negatively correlated with improvements in pain at rest (r - 0.41, p = 0.03) and with mobilisation (r - 0.37, p = 0.047). CONCLUSION: Lower levels of synovitis and higher levels of IL-6 and VEGFA were associated with better post-operative outcomes after UKA, which could be helpful for identifying UKA patients in clinical practice. LEVEL OF EVIDENCE: Level IV case series.

The Effect of Minor Adjustments to Tibial and Femoral Component Position on Soft Tissue Balance in Robotic Total Knee Arthroplasty.

BACKGROUND: Ideal goals for alignment and balance in total knee arthroplasty (TKA) remain controversial. We aimed to compare initial alignment and balance using mechanical alignment (MA) and kinematic alignment (KA) techniques and to analyze the percentage of knees that could achieve balance using limited adjustments to component position. METHODS: Prospective data on 331 primary robotic TKAs (115 MAs and 216 KAs) were analyzed. Medial and lateral virtual gaps were recorded in both flexion and extension. A computer algorithm was used to calculate potential (theoretical) implant alignment solutions to achieve balance within 1 millimeter (mm) without soft tissue release given an alignment philosophy (MA or KA), angular boundaries (±1, ±2, or ±3°), and gap targets (equal gaps or lateral laxity allowed). The percentage of knees that could theoretically achieve balance was compared. RESULTS: Less than 5% of TKAs were initially balanced. Limited adjustments to component position increased the percentage of TKAs that could be balanced in a graduated manner, with no difference between MA and KA start points: adjustments of ±1 (10% versus 6%, P = .17), ±2 (42% versus 39%, P = .61), or of ±3 (54% versus 51%, P = .66). A higher percentage of TKAs could be balanced when a greater range for lateral gap laxity was allowed. Balancing from KA resulted in increased joint line obliquity in the final implant alignment. CONCLUSION: A high percentage of TKAs can be balanced without soft tissue release using minor adjustments to component position. Surgeons should consider the relationship between alignment and balance goals when optimizing component positioning in TKA.

The Strongest Oxford Knee Score Predictors of Subsequent Revision are "Overall Pain," "Limping When Walking," and "Knee Giving Way".

BACKGROUND: The Oxford Knee Score (OKS) is used to measure knee arthroplasty outcomes; however, it is unclear which questions are more relevant. Our aims were to (1) identify which OKS question(s) were the strongest predictors of subsequent revision and (2) compare the predictive ability of the "pain" and "function" domains. METHODS: All primary total knee arthroplasties (TKAs) and unicompartmental knee arthroplasties (UKAs) in the New Zealand Joint Registry between 1999 and 2019 with an OKS at 6 months (TKA n = 27,708; UKA n = 8,415), 5 years (TKA n = 11,519; UKA n = 3,365) or 10 years (TKA n = 6,311; UKA n = 1,744) were included. Prediction models were assessed using logistic regressions and receiver operating characteristic analyses. RESULTS: A reduced model with 3 questions ("overall pain," "limping when walking," "knee giving way") showed better diagnostic ability than full OKS for predicting UKA revision at 6 months (area under the curve [AUC]: 0.80 versus 0.78; P < .01) and 5 years (0.81 versus 0.77; P = .02), and comparable diagnostic ability for predicting TKA revision at all time points (6 months, 0.77 versus 0.76; 5 years, 0.78 versus 0.75; 10 years, 0.76 versus 0.73; all not significant), and UKA revision at 10 years (0.80 versus 0.77; not significant). The pain domain had better diagnostic ability for predicting subsequent revision for both procedures at 5 and 10 years. CONCLUSION: Questions on "overall pain", "limping when walking", and "knee giving way" were the strongest predictors of subsequent revision. Attention to low scores from these questions during follow-up may allow for prompt identification of patients most at risk of revision.

Success of Debridement, Antibiotics, and Implant Retention in Prosthetic Joint Infection Following Primary Total Knee Arthroplasty: Results From a Prospective Multicenter Study of 189 Cases.

BACKGROUND: This study aimed to identify the success rate of debridement, antibiotics, and implant retention (DAIR) for prosthetic joint infection (PJI) in a large prospective cohort of patients undergoing total knee arthroplasty (TKA). The ability for different PJI classification systems to predict success was assessed. METHODS: Prospective data recorded in the Prosthetic Joint Infection in Australia and New Zealand Observational study were analyzed. One hundred eighty-nine newly diagnosed knee PJIs were managed with DAIR between July 2014 and December 2017. Patients were prospectively followed up for 2 years. A strict definition of success was used, requiring the patient being alive with documented absence of infection, no ongoing antibiotics and the index prosthesis in place. Success was compared against the Coventry (early PJI ≤1 month), International Consensus Meeting (early ≤90 days), Auckland (early <1 year), and Tsukayama (early ≤1 month, hematogenous >1 month with <7 days symptoms, chronic >1 month with >7 days symptoms) classifications. RESULTS: DAIR success was 45% (85/189) and was highest in early PJIs defined according to the Coventry (adjusted odds ratio [aOR] = 3.9, P = .01), the International Consensus Meeting (aOR = 3.1, P = .01), and the Auckland classifications (aOR = 2.6, P = .01). Success was lower in both hematogenous (aOR = 0.4, P = .03) and chronic infections (aOR = 0.1, P = .003). CONCLUSION: Time since primary TKA is an important predictor of DAIR success. Success was highest in infections occurring <1 month of the primary TKA and progressively decreased as time since the primary TKA increased.

The role of protective psychological factors, self-care behaviors, and HbA1c in young adults with type 1 diabetes.

OBJECTIVE: To investigate whether protective psychological factors in young adults with type 1 diabetes are associated with more optimal self-care behaviors and HbA1c, and to explore possible mediators between protective psychological factors and HbA1c. RESEARCH DESIGN AND METHODS: This cross-sectional study examined the associations between protective psychological factors (optimism, positive efficacy expectancies, and self-compassion), maladaptive psychological factors (depression, anxiety, and stress), self-care behaviors, and HbA1c in 113 young adults (17-25 years) with type 1 diabetes in Auckland, New Zealand. Pearson's correlations, multiple linear regressions, and multiple mediation analyses were used to examine associations and mediators. RESULTS: Higher positive efficacy expectancies (beliefs about coping with difficulties) were associated with more optimal HbA1c (ß = -0.26, 95% CI: -1.99 to -0.45) and more optimal self-care behaviors (ß = 0.33, 95% CI: 0.28 to 0.92) in the adjusted models. Higher levels of self-compassion were associated with more optimal self-care behaviors (ß = 0.27, 95% CI: 0.09 to 0.43). Depression was associated with less optimal self-care behaviors (ß = -0.35, 95% CI: -1.33 to -0.43) and stress was associated with less optimal HbA1c (ß = 0.26, 95% CI: 0.27 to 1.21). Mediation results suggested that self-care behaviors mediated the relationship between all three of the protective psychological factors and more optimal HbA1c, and that lower stress also mediated the relationship between higher self-compassion and more optimal HbA1c. CONCLUSIONS: This study adds to the emerging literature that protective psychological factors may play an adaptive role in improving health outcomes in young adults with type 1 diabetes. Interventions targeting protective psychological factors present a promising approach to optimizing wellbeing and self-care in youth with type 1 diabetes.

COVID-Associated Avascular Necrosis of the Maxilla-A Rare, New Side Effect of COVID-19.

PURPOSE: The purpose of this article is to present an interesting, rare case of a patient who experienced avascular necrosis of the maxilla associated with COVID-19 infection. METHODS AND RESULTS: Our team retrospectively evaluated this patient's chart after completion of surgical management. The patient is a 72-year-old male who presented to the University of Texas Health Science Center at Houston for surgical management of his infarcted maxilla, which developed as a sequela of infection with COVID-19. A literature review was completed using PubMed. Twenty-five articles are reviewed and discussed. CONCLUSIONS: Infection with COVID-19 confers a hypercoagulable state in patients, leading to various complications in the head and neck region. In our case report, we present a patient who developed avascular necrosis of the maxilla secondary to infection with COVID-19. Thromboembolic prophylaxis is imperative in COVID-19 patients due to the high rate of potential systemic complications.

Do TKAs in Patients with Higher BMI Take Longer, and is the Difference Associated with Surgeon Volume? A Large-database Study from a National Arthroplasty Registry.

BACKGROUND: Increased surgical time in TKA may impact economic costs and clinical outcomes. Prior work has found that TKAs in patients with high BMI take longer, and these patients may be at greater risk for postoperative complications like infection. However, these studies included small numbers of patients and surgeons from single institutions and they did not consider surgeon volume. QUESTIONS/PURPOSES: Using the New Zealand Joint Registry (NZJR), we asked: (1) Is there a relationship between increasing patient BMI and TKA operative time? (2) Is the effect of BMI on surgical time less pronounced among surgeons who perform more TKAs per year than those who perform fewer? METHODS: Data were collected from the NZJR between January 2010 and December 2018 as it is the only national registry that records both BMI and surgical time. Primary TKA performed for osteoarthritis by surgeons with more than 50 TKAs over the period of the study were identified. BMI and operative time (skin incision to closure in minutes) were recorded. Patients with the following were excluded: lateral parapatellar or minimally invasive approaches; navigated, patient-specific instrumentation, or robot-assisted TKA; uncemented or hybrid fixation; those with procedures performed by a trainee (all or part); or a nonosteoarthritic indication. Of 64,108 TKAs performed during the study period, a total of 42% (27,057) met our inclusion criteria. The primary outcome was the effect of BMI on operative time. Operative time is expressed in minutes as a mean for each single-unit BMI increase across all surgeons, controlled for other variables that might influence operative time such as patella resurfacing and cruciate-retaining versus posterior-stabilized designs. Overall, the mean operative time (skin incision to closure) was 79 ± 22 minutes. Surgical experience was assessed by subdividing surgeons into six groups according to the number of TKAs performed annually (< 10, 10 to 24, 25 to 49, 50 to 74, 75 to 99, and > 100). Statistical analyses were performed including a general linear model to assess the independent association between BMI and operative time, allowing for the effects of other patient and surgical features. In addition, linear regression analyses explored the associations between BMI and operative time in the whole group and within surgical volume groups. RESULTS: There was an association between increasing BMI and increasing surgical duration. The mean operative time increased from 75 ± 22 minutes in patients with a normal BMI of 25 kg/m2 to 87 ± 24 minutes in patients with a BMI of 40 kg/m2 to 94 ± 28 minutes in patients with a BMI > 50 kg/m2 (p < 0.001). Surgeons performing fewer than 25 TKAs per year took 14% longer to perform a TKA on a patient with a BMI of 40 kg/m2 than on a patient with a normal BMI of 25 kg/m2. However, surgeons performing greater than 25 TKAs per year took 10% longer. CONCLUSION: In this study, an increase BMI was associated with increased surgical time in TKA. Surgical duration for high-volume surgeons appears less influenced by increases in BMI than lower volume surgeons. Although the absolute increase in duration was small, prolonged surgical time may reduce theater productivity. Even though the issues around managing patients with high BMI are multifactorial and complex, considerations from these findings include ensuring appropriate theater scheduling and possibly referring patients with high BMI to specialist centers. Further studies should focus on assessing the effectiveness of such measures in reducing complications and improving outcomes in patients with elevated BMI. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Incidence of COVID-19 Patients in Oral and Maxillofacial Surgery.

PURPOSE: The SARS-CoV-2 global pandemic has resulted in widespread changes to healthcare practices across the United States. The purpose of this study is to examine the incidence of COVID-19 patients in the oral-maxillofacial surgery setting in order to help guide perioperative protocols during the pandemic. METHODS: In this retrospective cohort study, predictor variables (presence of preoperative symptoms on presentation, patient age, patient gender, patient race, hospital location, and presence of statewide stay-at-home orders) were examined with outcome variables (SARS-CoV-2 test results) over 10 months between March 2020 and December 2020 for patients undergoing surgical procedures in the operating room by the following Oral-Maxillofacial Surgery Departments: - Louisiana State University Health Sciences Center (Baton Rouge, LA) - University of Illinois at Chicago (Chicago, IL) - University of Texas Health Science Center at Houston (Houston, TX) Data analysis included Fisher exact tests to compare categorical variables across COVID test groups and Wilcoxon rank sum tests to compare continuous covariates. Two-sample tests of proportions were used to compare observed COVID-19 positivity rates to other study results. RESULTS: Out of 684 patients in 3 institutions, 17 patients (2.5%, 95% CI = 1.5 to 4.0%) tested positive for COVID-19 over a 10 month interval (March 1, 2020- December 31, 2020). The majority of patients that tested positive were asymptomatic in the preoperative setting (P-value = .09). They were significantly more likely to be African-American (P-value = .015) and less likely to have a stay-at-home order present at the time of surgery (P-value = .033). Age, gender, and hospital location did not play a statistically significant role. CONCLUSION: Our results demonstrate a 2.5% incidence of COVID-19 infection in the total population of patients undergoing scheduled oral-maxillofacial surgeries in 3 major healthcare systems across the United States. This data may help inform perioperative protocols and infection control measures during the COVID-19 pandemic.

Low percentage of surgeons meet the minimum recommended unicompartmental knee arthroplasty usage thresholds: Analysis of 3037 Surgeons from Three National Joint Registries.

PURPOSE: The reported usage of UKA is around 10% in the UK, Australian and New Zealand joint registries. However, some authors recommend that a higher UKA usage of 20%, or a minimum 12 UKA cases per year, would reduce revision rates. The purpose of this study was to analyze the percentage of surgeons performing the recommended thresholds in these 3 registries. METHODS: Data from the UK, Australian and New Zealand registry databases was utilized from the time period since their respective introduction until 2017. All primary TKA and UKA performed for the diagnosis of osteoarthritis by surgeons with more than 100 recorded knee arthroplasties in their respective registry were included. The results between the registries were compared and a pooled analysis was performed. The number of surgeons meeting the recommended caseload of > 20% UKA yearly or 12 UKA cases yearly was calculated. RESULTS: We identified 3037 knee surgeons performing 1,556,440 knee arthroplasties, of which 131,575 were UKA (8.45%). Over 50% of knee surgeons in each registry had a proportion of less than 5% UKA of their knee replacement procedures. After pooling of data, median surgeon UKA usage was 2.0% (IQR 0-9.1%). The percentage of surgeons meeting the proposed caseload criteria was highest in New Zealand, 16.3%, followed by the UK at 12.4% and Australia 11.3% (p = 0.28). CONCLUSION: More than 50% of knee surgeons in UK, Australian and New Zealand joint registries perform less than 5% of UKA yearly. The majority of experienced knee surgeons are not meeting the recommended minimum thresholds, which might indicate that the recommended thresholds are not feasible for the vast majority of knee surgeons. The reasons behind this require further research. LEVEL OF EVIDENCE: Level III retrospective registry study.