Purpose: To investigate the influence of surgical volume, and various patient-, injury-, and surgery-related factors, on meniscal treatment strategies in primary anterior cruciate ligament reconstruction (ACLR).

Methods: This retrospective cohort study analyzed patients with concomitant meniscal injuries undergoing primary ACLR, from 2008 to 2022, using data from the Swedish National Knee Ligament Registry. Surgeons and clinics were stratified by total caseload (cutoff: 50 ACLRs/surgeon, 500 ACLRs/clinic) and annual volume (cutoff: 29 ACLRs/year/surgeon, 56 ACLRs/year/clinic). To assess factors influencing medial meniscus or lateral meniscus repair, adjusted multivariable logistic regression was conducted, with results presented as odds ratios (OR) and 95% confidence intervals (CI).

Results: In total, 20,699 patients undergoing primary ACLR with concomitant meniscal injuries were included. Lower percentages of meniscus repair were seen among surgeons with low caseload and annual volume (LCLV) (13.3%-20.8%) compared with high caseload and annual volume (HCHV) surgeons (19.0%-29.8%), and at LCLV clinics (11.1%-18.3%) compared to HCHV clinics (21.5%-33.8%), all P < .001. Significantly decreased odds of medial meniscus repair were seen for patients operated on by LCLV surgeons (OR 0.82, 95% CI 0.70-0.96; P = .015) or at LCLV clinics (OR 0.56, 95% CI 0.50-0.64; P < .001. Similar results were seen for lateral meniscus repair with LCLV surgeons (OR 0.83, 95% CI 0.69-1.01; P = .067) and LCLV clinics (OR 0.62, 95% CI 0.53-0.72; P < .001). Additionally, younger age, female sex, shorter time from injury to surgery, and ACLRs performed more recently were associated with increased odds of repair.

Conclusions: Lower surgical volume significantly decreased the rates and odds of performing meniscal repair during primary ACLR. In contrast, ACLRs performed during more recent years, younger age, female sex, shorter time from injury to surgery, absence of chondral injuries, and injuries sustained during nonpivoting activities, positively influenced meniscal preservation.

Level of evidence: Level III, retrospective cohort study.

ObjectiveInjuries in women's football (soccer) have scarcely been investigated, and no study has been conducted in the highest competitive level involving club teams from different countries. Our aim was to investigate the time-loss injury epidemiology and characteristics among women's elite football players over four seasons.Methods596 players from 15 elite women's teams in Europe were studied prospectively during the 2018/2019 to 2021/2022 seasons (44 team seasons). Medical staff recorded individual player exposure and time-loss injuries. Injury incidence was calculated as the number of injuries per 1000 playing hours and injury burden as the number of days lost per 1000 hours.Results1527 injuries were recorded in 463 players with an injury incidence of 6.7 (95% CI 6.4 to 7.0) injuries per 1000 hours and a nearly fourfold higher incidence during match play compared with training (18.4, 95% CI 16.9 to 19.9 vs 4.8, 95% CI 4.5 to 5.1; rate ratio 3.8, 95% CI 3.5 to 4.2). Thigh muscle injuries (hamstrings 12%, 188/1527, and quadriceps 11%, 171/1527) were the most frequent injury, while anterior cruciate ligament (ACL) injury had the highest burden (38.0 days lost per 1000 hours, IQR 29.2-52.1) with median days lost of 292 (IQR 246-334) days. Concussions constituted 3% (47/1527) of all injuries, with more than half of them (55%, 26/47) due to ball-related impact.ConclusionAn elite women's football team can expect approximately 35 time-loss injuries per season. Thigh muscle injury was the most common injury and ACL injury had the highest injury burden.

ObjectivesTo: (1) describe hamstring injury incidence and burden in male professional football players over 21 seasons (2001/02 to 2021/22); (2) analyse the time-trends of hamstring muscle injuries over the most recent eight seasons (2014/15 to 2021/22); and (3) describe hamstring injury location, mechanism and recurrence rate. Methods3909 players from 54 teams (in 20 European countries) from 2001/02 to 2021/22 (21 consecutive seasons) were included. Team medical staff recorded individual player exposure and time-loss injuries. Time-trend analyses were performed with Poisson regression using generalised linear models. Results2636 hamstring injuries represented 19% of all reported injuries, with the proportion of all injuries increasing from 12% during the first season to 24% in the most recent season. During that same period, the percentage of all injury absence days caused by hamstring injuries increased from 10% to 20%. Between 2014/15 and 2021/22, training hamstring injury incidence increased (6.7% annually, 95% CI 1.7% to 12.5%) as did burden (9.0% annually, 95% CI 1.2% to 18.3%). During those years, the match hamstring injury incidence also increased (3.9% annually, 95% CI 0.1% to 7.9%) and with the same trend (not statistically significant) for match hamstring injury burden (6.2% annually, 95% CI -0.5% to 15.0%). ConclusionsHamstring injury proportions-in number of injuries and total absence days-doubled during the 21-year period of study. During the last eight seasons, hamstring injury rates have increased both in training and match play.

Purpose To study the epidemiology and return to play characteristics of anterior and posterior ankle impingement syndromes (AAIS and PAIS) over 18 consecutive seasons in male professional soccer players. Methods Between the 2001-2002 and 2018-2019 seasons, 120 European soccer teams were followed prospectively for various seasons. Time loss injuries and player exposures were recorded individually in 6754 unique players. Injury incidence and burden were reported as the number of injuries and days absence per 1000 h with 95% confidence intervals (CIs). Injury severity was reported as median absence in days with the interquartile range (IQR). Results Out of 25,462 reported injuries, 93 (0.4%) were diagnosed as AAIS (38%) or PAIS (62%) in 77 players. AAIS and PAIS were similar regarding injury characteristics except for a greater proportion of AAIS having a gradual onset (69% vs.47%; P = 0.03) and being re-injuries (31% vs. 9%; P = 0.01). Impingement syndromes resulted in an overall incidence of 0.03 injuries (95% CI 0.02-0.03) per 1000 h and an injury burden of 0.4 absence days per 1000 h. PAIS incidence was significantly higher than that for AAIS [0.02 (95% CI 0.002-0.03) vs. 0.01 (95% CI 0.005-0.01) injuries per 1000 h (RR = 1.7). The absence was significantly longer in AAIS than in PAIS [10 (22) vs. 6 (11) days; P = 0.023]. Impingement syndromes that presented with a gradual onset had longer absences in comparison to impingement with an acute onset [8 (22) vs. 5 (11) days; P = 0.014]. Match play was associated with a higher incidence and greater injury burden than training: 0.08 vs. 0.02 injuries per 1000 h (RR 4.7), respectively, and 0.9 vs. 0.3 days absence per 1000 h (RR 2.5). Conclusion Ankle injuries are frequent in mens professional soccer and ankle impingement is increasingly recognized as a common source of pain, limited range of motion, and potential time loss. In our study, ankle impingement was the cause of time loss in less than 0.5% of all injuries. PAIS was more frequently reported than AAIS, but AAIS was associated with more absence days and a higher re-injury rate than PAIS. The findings in this study can assist the physician in best practice management on ankle impingment syndromes in professional football.

Background and purpose - Patients in the Swedish healthcare system are insured against avoidable adverse events via Landstingens omsesidiga Forsakringsbolag (LoF). We assessed the reasons for compensation claims reported to LoF following an ACL injury.

Patients and methods - We searched the LoF database for compensation claims related to ACL injuries reported in 2005-2014, and cross-matched claims with the Swedish National Knee Ligament Register. We then performed a review of the medical records.

Results - We identified 530 eligible claims in 2005-2014. 352 (66%) claims were accepted by LoF and 178 claims were rejected. Accepted claims corresponded to fewer than 1% of ACL surgeries performed in the same period. The most common reasons for an accepted claim were postoperative septic arthritis followed by suboptimal surgery and delay in diagnosis and treatment.

Interpretation - There are different reasons for accepting a compensation claim following an ACL injury, which represents different treatment errors that can be avoided.

Background Studies on football and the coronavirus disease 2019 (COVID-19) have mainly focused on the lockdown consequences for player fitness, the resumption of football training, and how to safely restart the league play, but injury data are scarce.

Objective To describe the injury incidence and injury burden in mens professional football teams during the pandemic year of 2020.

Methods Nineteen teams in 12 countries prospectively registered data on player-exposure and time-loss injuries throughout 2020. All major football leagues were paused as a direct response to the pandemic in March 2020 and were thereafter completely cancelled or restarted after a lockdown interval of at least two months. Historical data from 43 teams in the same cohort during the five preceding years (2015-2019) were used as reference. Between-season and within-season comparisons were made for injury incidence (number of injuries per 1000 h) and injury burden (number of absence days per 1000 h) with 95% confidence intervals and interquartile ranges.

Results There was no increased match injury incidence or injury burden following the restart in 2020 compared with other time periods of 2020 and the corresponding periods 2015-2019. There was an increased training injury incidence and injury burden immediately during the lockdown in 2020, and they remained elevated also following the restart, being higher in 2020 compared with 2015-2019, respectively. The injury characteristics during the first months of the new 2020/21 season (August/September-December) were similar between the five teams that cancelled their 2019/20 season in March 2020 and the 14 teams that restarted their season in May/June 2020.

Conclusions There was no increased match injury incidence or injury burden following the COVID-19 lockdown and restart of the football season in 2020, but training injury incidence and injury burden were elevated and higher than in 2015-2019.

Objectives The primary objective was to study the adoption of the NHE programme in European football teams in the 2020/21 season and to compare it to the previous study. A second objective was to compare hamstring injury rates between teams that used the NHE programme in the team training and teams that used the NHE only for players with previous or current hamstring injuries. Methods Data about the implementation of the NHE programme and injury rates were included for 17 teams participating in the Elite Club Injury Study during the 2020/2021 season. Results One team (6%) used the full original NHE programme, and another four teams used it for all or most players in the team (team training group, n=5). Eleven teams used NHE only for players with a previous or current hamstring injury (individual training group), and one team did not use NHE. The team training group had fewer hamstring injuries (5 vs 11 per team, p=0.008) and a lower injury burden (12 vs 35 lay-off days per 1000 hours, p=0.003) than the individual training group. Conclusion Similar to previous reports, low adoption of the NHE programme was seen in the 2020/2021 season. The low adoption rate (13%) relates to the number of teams fully or partly using NHE programmes. Teams that used NHE for the whole team or most players had a lower hamstring injury burden than teams that used NHE only for individual players.

Background The risk of injury in adolescent handball is high, and shoulder and knee injuries are among the most frequent and burdensome. The Swedish Knee Control programme reduced the risk of anterior cruciate ligament injuries in female youth football players and traumatic knee injuries in male and female youth floorball players. However, to date, Knee Control has not been evaluated in an elite youth sport setting. The literature on the prevention of shoulder injuries in sport is scarce, and there are to our knowledge no previous studies evaluating the preventative efficacy of injury prevention exercise programmes (IPEPs) on shoulder injuries in adolescent handball players. Objectives To study the preventive efficacy of IPEPs on shoulder and knee injuries in adolescent elite handball players. Methods Eighteen Swedish handball-profiled secondary schools (clusters) with players aged 15-19 years, 54% males were randomised into either the Shoulder Group or Knee Group (interventions) or a Control Group. Players in the Shoulder Group were instructed to perform the Shoulder Control programme, and players in the Knee Group to perform the Knee Control programme, three times per week during May 2018 to May 2019. Control Group players continued their usual training. Outcomes were shoulder and knee injuries defined by the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. Intention-to-treat analyses were performed using Cox regression models with hazard rate ratios (HRRs) with corresponding 95% confidence intervals (CI). Results Six clusters (199 players) in the Shoulder Group, six clusters (216 players) in the Knee Group and six clusters (212 players) in the Control Group were included. There were 100 shoulder injuries and 156 knee injuries. The Shoulder Group had a 56% lower shoulder injury rate, HRR 0.44 (95% CI 0.29 to 0.68), and the Knee Group had a 31% lower knee injury rate, HRR 0.69 (95% CI 0.49 to 0.97) than the Control Group. The absolute risk reduction was 11% and 8%, and the number needed to treat was 9 and 13, respectively. Conclusions Adolescent elite handball players who performed the Shoulder Control and the Knee Control programmes had a lower risk of shoulder and knee injuries, respectively, than players who continued their usual training. Further research on how these two programmes can be combined to reduce knee and shoulder injuries in a time effective way is warranted. Trial registration ISRCTN15946352.

Background: There is limited epidemiological information on injury rates and injury mechanisms for lateral collateral ligament (LCL) and posterior cruciate ligament (PCL) injuries in male professional soccer. In addition, time trends and lay-off times for these injuries have not yet been determined.

Aim: To determine injury rates and circumstances of LCL and PCL injuries over 17 seasons in mens professional soccer.

Methods: A prospective cohort study, in which 68 professional European soccer teams were followed over 17 consecutive seasons (2001/2002 to 2017/2018). The teams medical staff recorded player exposure and time-loss injuries. Lay-off time was reported as the median and the first and third quartile. Injury rate was defined as the number of injuries per 1000 playerhours.

Results: One hundred and twenty-eight LCL and 28 PCL injuries occurred during 2,554,686 h of exposure (rate 0.05 and 0.01/1000 h, respectively). The median lay-off time for LCL injuries was 15 (Q(1)=7, Q(3)=32) days, while it was 31 days for PCL injuries (Q(1)=15, Q(3)=74). The match injury rate for LCL injuries was 11 times higher than the training injury rate (0.21 vs 0.02/1000 h, rate ratio [RR] 10.5, 95% CI 7.3 to 15.1 p&lt;0.001) and the match injury rate for PCL injuries was 20 times higher than the training injury rate (0.056 vs 0.003/1000 h, RR 20.1, 95% CI 8.2 to 49.6, p&lt;0.001). LCL injuries saw a significant annual decrease of approximately 3.5% (p=0.006). In total, 58% (63/108) of all LCL injuries and 54% (14/26) of all PCL injuries were related to contact mechanism.

Conclusion: This study with prospectively registered data on LCL and PCL injuries in mens professional soccer shows that the median lay-off from soccer for LCL and PCL injuries is approximately 2 and 4 weeks respectively. These rare knee ligament injuries typically occur during matches and are associated with a contact injury mechanism.

Background It has been hypothesised that injury risk after return to play following an injury absence is influenced by the amount of training completed before return to competition. Aim To analyse if the number of completed training sessions between return to play and the first subsequent match appearance was associated with the odds of injury in men's professional football. Methods From a cohort study, including 303 637 individual matches, 4805 first match appearances after return to play following moderate to severe injuries (≥8 days absence) were analysed. Rate ratios (RRs) were used to compare injury rates in the first match appearances with the average seasonal match injury rate. Odds ratios (ORs) were used to analyse associations between the number of completed training sessions and general (all injuries), muscle, and non-muscle injury odds. Results Injury rate in the first match after return to play was increased by 87% compared with the average seasonal match injury rate (46.9 vs 25.0/1000 hours, RR=1.87; 95% CI 1.64 to 2.14). The odds of injury dropped 7% with each training session before the first match (OR 0.93; 95% CI 0.87 to 0.98). The same association was found for muscle injuries (OR 0.87; 95% CI 0.79 to 0.95) but not for non-muscle injuries (OR 0.99; 95% CI 0.91 to 1.07). Conclusions Injury rates in the first match after injury are higher than the average seasonal match injury rate, but the propensity for player injury is decreased when players complete more training sessions before their first match.