Risk Factors for Knee Osteoarthritis in Retired Professional Footballers: A Cross-Sectional Study.

OBJECTIVE: To determine risk factors for 3 knee osteoarthritis (KOA) outcomes, knee pain (KP), radiographic KOA (RKOA), and total knee replacement (TKR) in professional footballers. DESIGN: This was a cross-sectional study involving a postal questionnaire, followed by radiographic assessment in a subcohort of responders. SETTINGS AND PARTICIPANTS: Four thousand seven hundred seventy-five questionnaires were sent to retired professional footballers, who had played in the English football league, and 1207 responded. Of these, 470 underwent knee radiographs. ASSESSMENT OF RISK FACTORS: Potential factors include age, body mass index (BMI), knee alignment, a history of football-related knee injury, and training hours (during career) were collected through the questionnaire. MAIN OUTCOME MEASURES: Knee osteoarthritis outcomes were current KP (pain for most days of the previous month), TKR (self-reported), and RKOA (observed through radiographs). RESULTS: Football-related injury was the strongest risk factor for KP [adjusted odds ratio (aOR), 4.22; 95% confidence interval (CI), 3.26-5.48], RKOA [aOR, 2.88; 95% CI, 1.81-4.59], and TKR [aOR, 4.83; 95% CI, 2.87-8.13]. Footballers had a 7% increased risk of RKOA for every 1000 hours trained. Although age and gout were associated with all 3 KOA outcomes, BMI, nodal osteoarthritis (OA), a family history of OA, knee malalignment, and 2D:4D ratio were associated with one or another of these 3 KOA outcomes. CONCLUSION: This study is the first to examine KOA risk factors in retired professional footballers. The study has identified several risk factors, both specific (eg, knee injury and training dose) and nonspecific (eg, age and gout) to footballers. This may be used to develop prevention strategies to reduce the risk of KOA in professional footballers after retirement.

Intra-articular Injection Administration in UK Ex-professional Footballers During Their Playing Careers and the Association with Post-career Knee Osteoarthritis.

BACKGROUND: The long-term risk from knee intra-articular (KIA) injections in professional athletes such as ex-footballers remains unknown. The use of KIA injections is controversial and remains anecdotally prolific as it is perceived as being safe/beneficial. The aim of this study was to determine the number, type and frequency KIA injections administered to retired professional footballers during their playing careers and the associations with post-career knee osteoarthritis (KOA). METHODS: This is a cross-sectional study involving a postal questionnaire (n = 1207) and subsequent knee radiographs in a random sample of questionnaire responders (n = 470). Footballers self-reported in the questionnaire whether they had received KIA injections and the estimated total number over the course of their playing career. Participant characteristics and football career-related details were also recorded. KOA was measured as self-reported knee pain (KP), total knee replacement (TKR) and radiographic KOA (RKOA). RESULTS: 44.5% of footballers had received at least one KIA injection (mean: 7.5; SD ± 11.2) during their professional career. 71% of knee injections were cortisone/corticosteroid based. Multivariate logistic regression, adjusting for age, body mass index (BMI) and significant knee injury identified that footballers with injections were two times more likely to have KP (OR 1.81, 95% CI 1.40-2.34) and TKR (OR 2.21, 95% CI 1.43-3.42) than those without injections. However, there was no association with RKOA (OR 1.30, 95% CI 0.85-2.01). Given, the association with KP and TKR, we found a significant dose-response relationship as the more injections a player received (by dose-response groups), the greater the risk of KP and TKR outcomes after adjustment for knee injury and other confounders (p for trend < 0.01). CONCLUSION: On average, 8 KIA injections were given to the ex-footballers during their professional career. The most commonly administered injections were cortisone based. These injections associated with KP and TKR after they retired. The associations are independent of knee injuries and are dose dependent. The study suggests that there may have been excessive use of KIA injections to expedite return to play and this contributed to detrimental long-term outcomes such as KP and TKR post-retirement from professional football.

Application of enhanced assimilable organic carbon method across operational drinking water systems.

Assimilable organic carbon (AOC) is known to correlate with microbial growth, which can consequently degrade drinking water quality. Despite this, there is no standardised AOC test that can be applied to drinking water distribution systems (DWDS). Herein we report the development of a quick, robust AOC that incorporates known strains Pseudomonas fluorescens strain P-17 and Spirillum strain NOX, a higher inoculum volume and enumeration using flow cytometry to generate a quicker (total test time reduced from 14 to 8 days), robust method. We apply the developed AOC test to twenty drinking water treatment works (WTW) to validate the method reproducibility and resolution across a wide range of AOC concentrations. Subsequently, AOC was quantified at 32 sample points, over four DWDS, for a year in order to identify sinks and sources of AOC in operative networks. Application of the developed AOC protocol provided a previously unavailable insight and novel evidence of pipes and service reservoirs exhibiting different AOC and regrowth behaviour. Observed correlations between AOC and microbial growth highlight the importance of monitoring AOC as an integral part of managing drinking water quality at the consumers tap.