C3 concentrations can be normal in patients with C3 glomerulopathy secondary to C3 nephritic factor.

C3 glomerulopathy (C3G) is a rare kidney disease caused by the glomerular deposition of C3 fragments secondary to alternative pathway complement dysregulation. C3 nephritic factors (C3Nef) are the most common acquired cause, and their detection has treatment and prognostic implications. Although C3 concentration can be normal in the presence of C3Nef, many laboratories will only perform C3Nef testing when C3 is low. We performed a retrospective study of all positive C3Nef results from the authors' laboratory since 2015 and found that two of the four patients with positive C3Nef and biopsy-confirmed C3G had normal C3 concentrations. This may be in part due to limitations in commercial C3 testing methods which use anti-C3c antisera directed against both C3 breakdown products and native C3. A normal C3 concentration should not preclude C3Nef testing in the appropriate clinical context.

Diagnosis and subtyping of idiopathic inflammatory myopathies: caution required in the use of myositis autoantibodies.

Detection of myositis autoantibodies (MAs) has utility in both the diagnosis and subtyping of idiopathic inflammatory myopathies (IIMs). Multiplex assays such as the Euroimmun line immunoassay (LIA) have significant limitations in rare diseases like IIM. A retrospective cohort study was performed on positive MA detected on LIA in 171 patients using the manufacturer's recommended cut-off. Only 16.7% were deemed true positive after clinical correlation. Autoantibody-specific cut-offs were created and applied to the original cohort, along with generically applied higher cut-offs. Positive predictive value (PPV) improved, but there was variable increase in false negatives. False positive MA results are common using LIA, but locally derived cut-offs can improve performance. Clinicians must be aware of the limitations of LIA, which is the commonest method for MA detection in Australasia.

Concussion incidence and mechanisms differ between elite females and males in Australian Football.

OBJECTIVES: To investigate the incidence and the game circumstances of concussion in the professional female (AFLW) and male (AFL) competitions of Australian Football, to identify potential targets for risk reduction. DESIGN: Retrospective cohort. METHODS: Concussion data were obtained from the AFL injury database, which included all concussions sustained by AFL (Male) players from 2015 to 18 and AFLW (Female) players from 2017 to 19. Concussions were diagnosed by experienced clinicians utilising standardised concussion assessment tools and injury definitions, as well as video review. Video footage was analysed to determine the circumstances each concussion occurred, which included the action and the contact-point of impact. RESULTS: The incidence of concussion was higher in the AFLW (Female) compared to the AFL (Male) (IRR = 2.12, 95 %CI 1.54 to 2.92). Video footage was available for 194/252 (77 %) concussions in the AFL and 35/44 (80 %) concussions in the AFLW. Male players were most frequently concussed during marking contests (28 %) with primary impact from the upper limb (22 %) or the shoulder (19 %). Conversely, being bumped (23 %) or tackled (20 %) were the main actions associated with concussion in female players, with the head (29 %) or the ground (23 %) the most common contact-points of impact. CONCLUSIONS: In elite Australian Football a higher incidence of concussion was demonstrated in female compared to male players. The mechanisms associated with concussion were also found to differ between male and female competitions, suggesting that different injury prevention interventions may be beneficial. In particular, a review of tackling and bumping skills training and education in the AFLW may reduce the risk of concussion.

Characterisation of Dissolved Organic Matter Fractions Released from Scottish Peatlands.

A high concentration of dissolved organic matter is intimately related to the chemistry and ecology of water environments linked to peatlands. To understand the variations in the chemical characteristics of peat derived dissolved organic matter, those in drainage water from natural vegetation and an area containing Sitka spruce (Picea sitchensis), surface water (dubh lochans), and stream water associated with a peatland in central Scotland were analyzed after fractionation into two fulvic acids that were desorbed from an XAD-8 column with water (FAs(H2O)) and 0.1 M NaOH (FAs(NaOH)), humic acids, and dissolved non-humic substances. The elemental composition and the carbon composition as estimated by 13C cross polarisation/magic angle spinning nuclear magnetic resonance did not differ significantly between the FAs(H2O) and FAs(NaOH), whilst the FAs(H2O) were differentiated from the FAs(NaOH) by the greater proportion of carboxy groups with a low pKa at approximately 2. The carboxy group content and the distribution of carboxy groups with respect to the pKa of dissolved non-humic substances were similar to those of FAs(H2O), suggesting their importance as a metal carrier in water systems associated with peatland.

Efficacy of Primary Repair in Professional Athletes with Chronic Radial Collateral Ligament Injuries of Thumb Metacarpophalangeal Joint.

Background: Management of grade III injuries of the radial collateral ligament (RCL) of the thumb is controversial. These injuries are often treated with early surgery. However, early surgery may not be practical for the professional athlete. We report on the outcome of delayed primary repair of chronic RCL injuries without the use of tendon grafts or tendon transfers. Methods: Twelve elite professional athletes with 15 soft tissue RCL injuries who underwent delayed surgery (greater than 6 weeks) were included in this study. Athletes were managed with splinting and ongoing play during the sporting season, and underwent surgery at the conclusion of the season. Mean duration from injury to surgery was 5 months. Mean follow-up was 4.2 years after surgery. Patient-report outcome measures including pain, satisfaction rating, and disability of the arm, shoulder and hand (DASH) scores were collected. Examination findings including range of motion, laxity, and grip and pinch strength were also measured. Return-to-play data were collected for all athletes. Results: The RCL was able to be primarily repaired with suture anchors in all cases. All twelve patients were able to return to competitive play at the same pre-injury professional level. Post-operative joint function such as range of motion and laxity were comparable to the unaffected contralateral side, as were grip and lateral pinch strengths. Tip-pinch strength is lower compared to the unaffected side, but is comparable to age and sex-matched reference group. Conclusions: Delayed primary repair of the RCL is a viable option and results in satisfactory long-term outcomes. This option may be more preferable to the professional athlete who wishes to avoid surgery during the sporting season.

The relationship of team and individual athlete performances on match quarter outcome in elite women's Australian Rules football.

OBJECTIVES: To evaluate the relationships between the athlete distribution of team performance indicators and quarter outcome in elite women's Australian Rules football matches. DESIGN: Retrospective longitudinal cohort analysis. METHODS: Thirteen performance indicators were obtained from 56 matches across the 2017 and 2018 Australian Football League Women's (AFLW) seasons. Absolute and relative values of 13 performance indicators were obtained for each athlete, in each quarter of all matches. Eleven features were further extracted for each performance indicator, resulting in a total of 169 features. Generalised estimating equations (GEE) and regression decision trees were run across the different feature sets and dependent variables, resulting in 22 separate models. RESULTS: The GEE algorithm produced slightly lower mean absolute errors across all dependent variables and feature sets comparative to the regression decision tree models. Quarter outcome was more accurately explained when considered as total points scored comparative to quarter score margin. Team differential and the 75th percentile of individual athlete Inside 50s were the strongest features included in the models. CONCLUSIONS: Modelling performance statistics by quarter outcomes provides specific practical information for in-game tactics and coaching in relation to athlete performances each quarter. Within the current elite women's Australian Rules football competition, key high performing individual athletes' skilled performances within matches contribute more to success rather than a collective team effort.

Orthotic intervention incorporating the dart-thrower's motion as part of conservative management guidelines for treatment of scapholunate injury.

STUDY DESIGN: Case series. INTRODUCTION: This paper describes conservative guidelines for the management of scapho-lunate interosseous ligament (SLIL) injury including fabrication of an orthosis that restricts active wrist movement to the dart-throwers (DTM) plane. PURPOSE OF THE STUDY: The dart throwers' orthosis (DTO) was designed as a response to biomechanical studies suggesting that restraining motion to the DTM would off-load a deficient SLIL. METHODS: After six weeks of wearing the DTO, the 5 patients in this case series initiated an exercise program that incorporated wrist proprioceptive training and specific muscle strengthening. DISCUSSION: The DTO was designed to incorporate controlled movement in order to better integrate the secondary wrist stabilizers in wrists that had a deficient SLIL. The orthosis and the exercise program harnessed proprioceptive influences using active motion within the DTM plane, and stimulated mechanoreceptors so as to enhance stability. RESULTS: All patients demonstrated improvement in subjective and objective outcomes including self-reported pain and function. CONCLUSIONS: Orthotic intervention that controls motion within the DTM, combined with an appropriate proprioceptive rehabilitation program, may provide a viable conservative treatment option for patients with a similar clinical presentation. LEVEL OF EVIDENCE: 4.