Depression and anxiety-related disorders and suicide among Swedish male elite football players: a nationwide cohort study.

OBJECTIVE: To assess whether male elite football players, during and after their active career, were at increased risk of depression and anxiety-related disorders and suicide, as compared with the general male population. METHODS: We included male football players active in the Swedish top division 1924-2019 and general male population (matched to football players based on age and region of residence) aged <65 years in 1997. Using nationwide registers, we followed the football players from their first season in the top division (or the date of their first registered residency in Sweden) or 1 January 1997, and compared the risk of depression and anxiety-related disorders (captured through diagnoses from hospital admissions and outpatient visits, and use of prescription drugs) among football players versus controls. In a secondary analysis using data from death certificates, we compared the risk of suicide between football players and general population males who were alive in 1969 (when cause of death became available) . RESULTS: During follow-up through 31 December 2020, 504 (13.6%) of 3719 football players and 7455 (22.3%) of 33 425 general population males had a depression or anxiety-related disorder. In analyses accounting for age, region of residence and calendar time, the risk of anxiety and depression-related disorders was lower among football players versus general population males (HR 0.61, 95% CI 0.55 to 0.66). The protective association was attenuated with increasing age, and from around age 70 years the risk was similar in the two groups. The risk of suicide was lower among football players versus general population males (HR 0.48, 95% CI 0.32 to 0.72). CONCLUSIONS: In this nationwide cohort study in Sweden, elite male football players had a lower risk of depression and anxiety-related disorders and suicide as compared with the general population.

Patient´s height and sex predict graft diameter. A cohort study of 4,519 patients with primary anterior cruciate ligament reconstruction using semitendinosus autograft.

PURPOSE: To determine whether anthropometric measurements (height and weight), sex, age and pre-injury Tegner activity scale (TAS) were predictors of the quadrupled semitendinosus (ST) graft diameter in primary anterior cruciate ligament reconstruction (ACLR). METHODS: A total of 4,519 patients who underwent primary ACLR with a quadrupled ST autograft were included. Anthropometric measurements (height and weight), sex, age, pre-injury TAS were collected. Correlation coefficients and multiple linear regression analysis were used to determine the relationship between graft diameter and anthropometrics measurements (height and weight), sex, age and pre-injury TAS. RESULTS: The diameter of the quadrupled ST graft was correlated positively to height (r =.021, P <.001), age (r =.005, P <.001) and weight (r =.004, P =.001) and negatively to female sex (r = -.297, P <.001). A regression equation was estimated to predict the ST graft diameter for men as 4.245 + 0.021 x height (cm) + 0.004 x age (years) + 0.005 x weight (kg) and for women as 3.969 + 0.021 x height (cm) + 0.004 x age (years) + 0.005 x weight (kg). CONCLUSIONS: Height, age and weight were positively correlated, whereas female sex was negatively correlated to the diameter of the quadrupled ST graft. Knowledge of these factors can be used for the preoperative estimation of the graft diameter which can be helpful for appropriate graft choice.

The Addition of the Gracilis Tendon to a Semitendinosus Tendon Autograft Is Not Associated With Knee Muscle Strength, Subjective Knee Function, or Revision Surgery After Anterior Cruciate Ligament Reconstruction.

PURPOSE: To evaluate and compare isokinetic knee muscle (extension and flexion) strength, single-leg hop (SLH) test performance, anterior knee laxity, subjective knee function, and the 2-year revision surgery risk between patients who underwent anterior cruciate ligament reconstruction (ACLR) with semitendinosus tendon (ST) autografts and patients who underwent ACLR with ST and gracilis tendon (ST-G) autografts. METHODS: We identified patients aged 16 years or older who underwent primary ACLR with hamstring tendon autografts at our institution from January 2005 to December 2020 and had no associated ligament injuries. Isokinetic knee muscle strength and SLH test performance were assessed 6 months postoperatively. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed preoperatively and 6 months postoperatively. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1 and 2 years postoperatively. Patients who underwent revision ACLR at any institution in Sweden within 2 years of primary surgery were identified through the Swedish National Knee Ligament Registry. RESULTS: A total of 6,974 patients (5,479 with ST and 1,495 with ST-G) were included. There were no significant differences in extension and flexion strength or SLH test performance between the groups. Preoperatively, there was no significant difference in knee laxity between the ST and ST-G groups. Postoperatively, the ST-G group had significantly increased mean side-to-side (STS) laxity (2.1 ± 2.3 mm vs 1.7 ± 2.2 mm, P < .001) and showed a trend toward increased STS laxity according to the International Knee Documentation Committee form, with significantly fewer patients with STS laxity of 2 mm or less (58.4% vs 65.8%) and significantly more patients with STS laxity between 3 and 5 mm (35.0% vs 29.9%) or greater than 5 mm (6.6% vs 4.3%) (P < .001). The only significant difference in subjective knee function was for the KOOS Quality of Life subscale score in favor of the ST group preoperatively (37.3 ± 21.4 vs 35.1 ± 19.9, P = .001). No other significant differences between the groups were found preoperatively and 1 and 2 years postoperatively for any of the KOOS subscales. The overall revision ACLR rate within 2 years of primary surgery was 2.0% (138 of 6,974 patients). The revision ACLR risk in the ST-G group (1.7%, 25 of 1,495 patients) was not significantly different from that in the ST group (2.1%, 113 of 5,479 patients) (hazard ratio, 0.80; 95% confidence interval, 0.50-1.24; P = .32). CONCLUSIONS: The addition of the gracilis tendon to an ST autograft was not associated with knee muscle strength, SLH test performance, subjective knee function, or the risk of revision surgery after ACLR. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Surgeon's experience, sports participation and a concomitant MCL injury increase the use of patellar and quadriceps tendon grafts in primary ACL reconstruction: a nationwide registry study of 39,964 surgeries.

PURPOSE: To investigate the influence of surgeon-related factors and clinic routines on autograft choice in primary anterior cruciate ligament reconstruction (ACLR). METHODS: Data from the Swedish National Knee Ligament Registry (SNKLR), 2008-2019, were used to study autograft choice (hamstring; HT, patellar; PT, or quadriceps tendon; QT) in primary ACLR. Patient/injury characteristics (sex, age at surgery, activity at time of injury and associated injuries) and surgeon-/clinic-related factors (operating volume, caseload and graft type use) were analyzed. Surgeon/clinic volume was divided into tertiles (low-, mid- and high-volume categories). Multivariable logistic regression was performed to assess variables influencing autograft choice in 2015-2019, presented as the odds ratio (OR) with a 95% confidence interval (CI). RESULTS: 39,964 primary ACLRs performed by 299 knee surgeons in 91 clinics were included. Most patients received HT (93.7%), followed by PT (4.2%) and QT (2.1%) grafts. Patients were mostly operated on by high-volume (> 28 ACLRs/year) surgeons (68.1%), surgeons with a caseload of ≥ 50 ACLRs (85.1%) and surgeons with the ability to use ≥ two autograft types (85.9%) (all p < 0.001). Most patients underwent ACLR at high-volume (> 55 ACLRs/year) clinics (72.2%) and at clinics capable of using ≥ two autograft types (93.1%) (both p < 0.001). Significantly increased odds of receiving PT/QT autografts were found for ACLR by surgeons with a caseload of ≥ 50 ACLRs (OR 1.41, 95% CI 1.11-1.79), but also for injury during handball (OR 1.31, 95% CI 1.02-1.67), various other pivoting sports (basketball, hockey, rugby and American football) (OR 1.59, 95% CI 1.24-2.03) and a concomitant medial collateral ligament (MCL) injury (OR 4.93, 95% CI 4.18-5.80). In contrast, female sex (OR 0.87, 95% CI 0.77-0.97), injury during floorball (OR 0.71, 95% CI 0.55-0.91) and ACLR by mid-volume relative to high-volume surgeons (OR 0.62, 95% CI 0.53-0.73) had significantly reduced odds of receiving PT/QT autografts. CONCLUSION: An HT autograft was used in the vast majority of cases, but PT/QT autografts were used more frequently by experienced surgeons. Prior research has demonstrated significant differences in autograft characteristics. For this reason, patients might benefit if surgery is performed by more experienced surgeons. LEVEL OF EVIDENCE: Level III.

Increased occurrence of ACL injuries for football players in teams changing coach and for players going to a higher division.

PURPOSE: To identify football-specific factors associated with ACL injuries that can be targeted for sport-specific injury prevention. METHODS: A study-specific questionnaire was developed to study the characteristics of ACL injuries in football including intrinsic, extrinsic, and injury specific factors. The questionnaire was available at the Swedish national knee ligament registry's website for the football players to voluntarily fill out. Data are presented on group level for all football players in total and for females and males separate to examine gender-specific differences. The results are based on answers collected over a 3-year period from 2875 football players, 1762 (61%) males and 1113 (39%) females. RESULTS: ACL were more frequently sustained during games 66% than during practices 25%. The injury mechanism was non-contact in 59% and contact in 41%. For the contact injuries during games, no action was taken by the referee in 63% of the situation and a red card was shown in 0.5%. The risk of ACL injury was highest early in the football game with 47% sustained during the first 30 min and 24% in the first 15 min. Players changing to a higher level of play 15% had a higher rate of ACL injuries than players changing to a lower level 8%. This difference was especially seen in female football players with 20% of ACL injuries being sustained by players going to a higher division compared to 7% for those going to a lower division. 15% of the male and 21% of the female ACL injuries occurred in teams with a coach change during the season. Knee control exercises to warm up was used by 31% of the female players and 16% of the males. 40% of the players reported that they did not plan on returning to football. CONCLUSION: Neuromuscular training programs have proven to reduce ACL injuries, but greater adherence to these remains a challenge as only 1 in 5 of the ACL-injured football players report using them. Teams changing coach and players going to a higher division appear to have an increased risk of ACL injury warranting attention and further investigations. LEVEL OF EVIDENCE: IV.

Age, time from injury to surgery and hop performance after primary ACLR affect the risk of contralateral ACLR.

PURPOSE: To evaluate factors affecting the risk of contralateral anterior cruciate ligament reconstruction (ACLR) within 5 years of primary ACLR. METHODS: Primary ACLRs performed at Capio Artro Clinic, Stockholm, Sweden, during the period 2005-2014, were reviewed. The outcome of the study was the occurrence of contralateral ACLR within 5 years of primary ACLR. Univariable and multivariable logistic regression analyses were employed to identify preoperative [age, gender, body mass index (BMI), time from injury to surgery, pre-injury Tegner activity level], intraoperative [graft type, medial meniscus (MM) and lateral meniscus (LM) resection or repair, cartilage injury] and postoperative [limb symmetry index (LSI) for quadriceps and hamstring strength and single-leg-hop test performance at 6 months] risk factors for contralateral ACLR. RESULTS: A total of 5393 patients who underwent primary ACLR were included. The incidence of contralateral ACLR within 5 years was 4.7%. Univariable analysis revealed that age ≥ 25 years, BMI ≥ 25 kg/m2, time from injury to surgery ≥ 12 months and the presence of a cartilage injury reduced the odds, whereas female gender, pre-injury Tegner activity level ≥ 6, quadriceps and hamstring strength and a single-leg-hop test LSI of ≥ 90% increased the odds of contralateral ACLR. Multivariable analysis showed that the risk of contralateral ACLR was significantly affected only from age ≥ 25 years (OR 0.40; 95% CI 0.28-0.58; P < 0.001), time from injury to surgery ≥ 12 months (OR 0.48; 95% CI 0.30-0.75; P = 0.001) and a single-leg-hop test LSI of ≥ 90% (OR 1.56; 95% CI 1.04-2.34; P = 0.03). CONCLUSION: Older age (≥ 25 years) and delayed primary ACLR (≥ 12 months) reduced the odds, whereas a symmetrical (LSI ≥ 90%) 6-month single-leg-hop test increased the odds of contralateral ACLR within 5 years of primary ACLR. Knowledge of the factors affecting the risk of contralateral ACLR is important when it comes to the appropriate counselling for primary ACLR. Patients should be advised regarding factors affecting the risk of contralateral ACLR. LEVEL OF EVIDENCE: Level III.

Long-term evaluation of pediatric ACL reconstruction: high risk of further surgery but a restrictive postoperative management was related to a lower revision rate.

INTRODUCTION: The guidelines regarding rehabilitation after pediatric anterior cruciate ligament reconstruction (ACLR) are sparse. The aim of the study was to retrospectively describe the long-term outcome regarding further surgery and with special emphasis on the revision rate after two different postoperative rehabilitation programs following pediatric ACLR. MATERIAL AND METHODS: 193 consecutive patients < 15 years of age who had undergone ACLR at two centers, A (n = 116) and B (n = 77), in 2006-2010 were identified. Postoperative rehabilitation protocol at A: a brace locked in 30° of flexion with partial weight bearing for 3 weeks followed by another 3 weeks in the brace with limited range of motion 10°-90° and full weight bearing; return to sports after a minimum of 9 months. B: immediate free range of motion and weight bearing as tolerated; return to sports after a minimum of 6 months. The mean follow-up time was 6.9 (range 5-9) years. The mean age at ACLR was 13.2 years (range 7-14) years. The primary outcome measurement in the statistical analysis was the occurrence of revision. Multivariable logistic regression analysis was performed to investigate five potential risk factors: surgical center, sex, age at ACLR, time from injury to ACLR and graft diameter. RESULTS: Thirty-three percent had further surgery in the operated knee including a revision rate of 12%. Twelve percent underwent ACLR in the contralateral knee. The only significant variable in the statistical analysis according to the multivariable logistic regression analysis was surgical center (p = 0.019). Eight percent of the patients at center A and 19% of the patients at B underwent ACL revision. CONCLUSIONS: Further surgery in the operated knee could be expected in one third of the cases including a revision rate of 12%. The study also disclosed a similar rate of contralateral ACLR at 12%. The revision rate following pediatric ACLR was lower in a center which applied a more restrictive rehabilitation protocol. LEVEL OF EVIDENCE: Case-control study, Level III.

How to translate and locally adapt a PROM. Assessment of cross-cultural differential item functioning.

Translating patient-reported outcome measures (PROMs) can alter the meaning of items and undermine the PROM's psychometric properties (quantified as cross-cultural differential item functioning [DIF]). The aim of this paper was to present the theoretical background for PROM translation, adaptation, and cross-cultural validation, and assess how PROMs used in sports medicine research have been translated and adapted. We also assessed DIF for the Knee Injury and Osteoarthritis Outcome Score (KOOS) across Danish, Norwegian, and Swedish versions. We conducted a search in PubMed and Scopus to identify the method of translation, adaptation, and validation of PROMs relevant to musculoskeletal research. Additionally, 150 preoperative KOOS questionnaires were obtained from the Scandinavian knee ligament reconstruction registries, and cross-cultural DIF was evaluated using confirmatory factor analysis and Rasch analysis. There were 392 studies identified, describing the translation of 61 PROMs. Ninety-four percent were performed with forward-backward technique. Forty-nine percent used cognitive interviews to ensure appropriate wording, understandability, and adaptation to the target culture. Only two percent were validated according to modern test theory. No study assessed cross-cultural DIF. One KOOS subscale showed no cross-cultural DIF, two had DIF with respect to some (but not all) items, and thus conversion tables could be constructed, and two KOOS subscales could not be pooled. Most PROM translations are of undocumented quality, despite the common conclusion that they are valid and reliable. Scores from three of five KOOS subscales can be pooled across the Danish, Norwegian, and Swedish versions, but two of these must be adjusted for DIF.

Delayed Anterior Cruciate Ligament Reconstruction Increases the Risk of Abnormal Prereconstruction Laxity, Cartilage, and Medial Meniscus Injuries.

PURPOSE: To determine the association between a delay in anterior cruciate ligament reconstruction (ACLR), age, sex, body mass index (BMI) and cartilage injuries, meniscus injuries, meniscus repair, and abnormal prereconstruction laxity. METHODS: Patients who underwent primary ACLR at our institution from January 2005 to March 2017, with no associated ligament injuries, were identified. Logistic regression analyses were used to evaluate whether delay in ACLR, age, sex, and BMI were risk factors for cartilage and meniscus injuries, meniscus repair, and abnormal (side-to-side difference >5 mm) prereconstruction laxity. RESULTS: A total of 3976 patients (mean age 28.6 ± 10.6 years, range 10-61 years) were included. The risk of cartilage injury increased with a delay in ACLR (12-24 months: odds ratio [OR] 1.20; 95% confidence interval [CI] 1.05-1.29; P = .005; and > 24 months: OR 1.20; 95% CI 1.11-1.30; P < .001) and age ≥30 years (OR 2.27; 95% CI 1.98-2.60; P < .001). The risk of medial meniscus (MM) injury increased with a delay in ACLR (12-24 months: OR 1.20; 95% CI 1.07-1.29; P = .001; and >24 months: OR 1.22; 95% CI 1.13-1.30; P < .001), male sex (OR 1.16; 95% CI 1.04-1.30; P = .04) and age ≥30 years (OR 1.20; 95% CI 1.04-1.33; P = .008). The risk of lateral meniscus (LM) injury decreased with a delay in ACLR of >3 months and age ≥30 years (OR 0.75; 95% CI 0.66-0.85; P < .001), whereas it increased with male sex (OR 1.32; 95% CI 1.22-1.41; P < .001). MM repairs relative to MM injury decreased with a delay in ACLR (6-12 months: OR 0.70; 95% CI 0.54-0.92; P = .01; 12-24 months: OR 0.69; 95% CI 0.57-0.85; P < .001; >24 months: OR 0.61; 95% CI 0.52-0.72; P < .001) and age ≥30 years (OR 0.60; 95% CI 0.48-0.74; P < .001). LM repairs relative to LM injury only decreased with age ≥30 years (OR 0.34; 95% CI 0.26-0.45; P < .001). The risk of having abnormal knee laxity increased with a delay in ACLR of >6 months and MM injury (OR 1.52; 95% CI 1.16-1.97; P = .002), whereas it decreased with a BMI of ≥25 (OR 0.68; 95% CI 0.52-0.89; P = .006). CONCLUSIONS: A delay in ACLR of >12 months increased the risk of cartilage and MM injuries, whereas a delay of >6 months increased the risk of abnormal prereconstruction laxity and reduced the likelihood of MM repair. To reduce meniscus loss and the risk of jeopardizing knee laxity, ACLR should be performed within 6 months after the injury. LEVEL OF EVIDENCE: Level III, retrospective therapeutic comparative study.

Age, time from injury to surgery and quadriceps strength affect the risk of revision surgery after primary ACL reconstruction.

PURPOSE: To identify preoperative, intraoperative and postoperative factors associated with revision anterior cruciate ligament reconstruction (ACLR) within 2 years of primary ACLR. METHODS: Patients who underwent primary ACLR at our institution, from January 2005 to March 2017, were identified. The primary outcome was the occurrence of revision ACLR within 2 years of primary ACLR. Univariate and multivariate logistic regression analyses were used to evaluate preoperative [age, gender, body mass index (BMI), time from injury to surgery, pre-injury Tegner activity level], intraoperative [graft type, graft diameter, medial meniscus (MM) and lateral meniscus (LM) resection or repair, cartilage injury] and postoperative [side-to-side (STS) anterior laxity, limb symmetry index (LSI) for quadriceps and hamstring strength and single-leg-hop test performance at 6 months] risk factors for revision ACLR. RESULTS: A total of 6,510 primary ACLRs were included. The overall incidence of revision ACLR within 2 years was 2.5%. Univariate analysis showed that age < 25 years, BMI < 25 kg/m2, time from injury to surgery < 12 months, pre-injury Tegner activity level ≥ 6, LM repair, STS laxity > 5 mm, quadriceps strength and single-leg-hop test LSI of ≥ 90% increased the odds; whereas, MM resection and the presence of a cartilage injury reduced the odds of revision ACLR. Multivariate analysis revealed that revision ACLR was significantly related only to age < 25 years (OR 6.25; 95% CI 3.57-11.11; P < 0.001), time from injury to surgery < 12 months (OR 2.27; 95% CI 1.25-4.17; P = 0.007) and quadriceps strength LSI of ≥ 90% (OR 1.70; 95% CI 1.16-2.49; P = 0.006). CONCLUSION: Age < 25 years, time from injury to surgery < 12 months and 6-month quadriceps strength LSI of ≥ 90% increased the odds of revision ACLR within 2 years of primary ACLR. Understanding the risk factors for revision ACLR has important implications when it comes to the appropriate counseling for primary ACLR. In this study, a large spectrum of potential risk factors for revision ACLR was analyzed in a large cohort. Advising patients regarding the results of an ACLR should also include potential risk factors for revision surgery. LEVEL OF EVIDENCE: III.

Knee laxity and functional knee outcome after contralateral ACLR are comparable to those after primary ACLR.

PURPOSE: To evaluate and compare knee laxity and functional knee outcome between primary and contralateral anterior cruciate ligament (ACL) reconstruction. METHODS: Patients who underwent primary and subsequent contralateral ACL reconstruction (ACLR) at Capio Artro Clinic, Stockholm, Sweden, from 2001 to 2017, were identified in our local database. The inclusion criteria were: the same patients who underwent primary and contralateral hamstring tendon or bone-patellar tendon-bone autograft ACLR and no associated ligament injuries. The KT-1000 arthrometer, with an anterior tibial load of 134 N, was used to evaluate knee laxity preoperatively and 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at the 1-year follow-up. RESULTS: A total of 326 patients with isolated primary and contralateral ACLR met the inclusion criteria (47.9% males; mean age at primary ACLR 23.9 ± 9.4 years and contralateral ACLR 27.9 ± 10.1 years). The arthrometric laxity measurements were available for primary and contralateral ACLR for 226 patients. The mean preoperative and postoperative anterior tibial translation (ATT), as well as the mean ATT reduction from preoperatively to postoperatively, did not differ significantly between primary and contralateral ACLR. The KOOS was available for primary and contralateral ACLR for 256 patients. No significant differences were found preoperatively and at the 1-year follow-up between primary and contralateral ACLR for any of the five KOOS subscales. CONCLUSION: The findings in this study showed that anterior knee laxity and functional knee outcome after contralateral ACLR are comparable to those after primary ACLR. It is important for clinicians to counsel patients about their expectations after contralateral ACLR. This study shows that the results after contralateral ACLR in terms of knee laxity and functional knee outcome are predictable and likely to be comparable to those after primary ACLR. LEVEL OF EVIDENCE: Level III.

High Risk of Further Anterior Cruciate Ligament Injury in a 10-Year Follow-up Study of Anterior Cruciate Ligament-Reconstructed Soccer Players in the Swedish National Knee Ligament Registry.

PURPOSE: To follow up on soccer players 10 years after a primary anterior cruciate ligament (ACL) reconstruction to find out how many players returned to play soccer, what influenced their decision, and if there are any differences in additional ACL injuries (graft failure and/or contralateral ACL injury) between those who returned to play and those who did not. METHODS: The study cohort consists of 1661 soccer players from the Swedish National Knee Ligament Registry. A questionnaire was sent to each player regarding their return to play and additional knee injuries that may have occurred 10 years after their primary ACL. The results are based on the 684 responders. Data such as age, sex, surgical procedural data, associated injuries, patient-reported outcome measures, and additional knee surgeries were collected from the registry. RESULTS: In this study, 51% returned to play soccer. For those who did not return to play, the primary reason was knee related (65.4% of the cases). The most common knee-related reasons for not returning were pain and/or instability (50%; n = 109), followed by fear of reinjury (32%; n = 69). Players who return to soccer have a significantly higher risk of additional ACL injury. Of the players who returned to play soccer, 28.7% (odds ratio [OR] 2.3, P < .001) had additional ACL injury, 9.7% (OR 2.9, P < .001) had a graft failure and 20.6% (OR 2.1, P < .001) had a contralateral ACL injury. CONCLUSIONS: Players that return to soccer have a significantly higher risk of sustaining further ACL injury. Only half of the soccer players return to play after ACL reconstruction, and in two-thirds of those who did not return, the reason was knee related. The high risk of sustaining additional knee injury is of serious concern to the player's future knee health and should be considered when deciding on a return to play. LEVEL OF EVIDENCE: Level III retrospective case-control study.

Meniscus Repair Does Not Result in an Inferior Short-term Outcome Compared With Meniscus Resection: An Analysis of 5,378 Patients With Primary Anterior Cruciate Ligament Reconstruction.

PURPOSE: To compare the preoperative and 1- and 2-year postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) subscale scores between isolated anterior cruciate ligament reconstruction (ACLR) and ACLR with additional medial meniscus (MM) and/or lateral meniscus (LM) resection or repair. METHODS: A total of 5,378 patients who underwent primary ACLR, with no associated ligament injuries, at our institution from January 2005 to December 2015 were included. The KOOS subscale scores were used to evaluate patients preoperatively and at 1- and 2-year postoperative follow-up assessments. Patients who underwent isolated ACLR and those who underwent ACLR with additional MM resection, MM repair, LM resection, LM repair, MM plus LM resection, or MM plus LM repair were compared by use of an analysis of covariance, with age, sex, graft, and cartilage injury as covariates. RESULTS: Postoperatively, at both 1- and 2-year follow-up assessments, no significant differences were found between the groups for any of the 5 KOOS subscales. Preoperatively, a significant difference between the groups was found for the KOOS Symptoms (P < .001), Pain (P < .001), Activities of Daily Living (ADL) (P < .001), and Sport and Recreation (Sport/Rec) (P = .01) subscale scores. The lowest scores were found for the group undergoing ACLR and MM plus LM repair (Symptoms, 70.1 ± 17.3; Pain, 71.4 ± 18.5; ADL, 80.6 ± 20.5; and Sport/Rec, 35.7 ± 28.1), whereas the mean scores for the other groups ranged from 71.2 ± 18.7 to 76.5 ± 17.1 for Symptoms, from 76.1 ± 17.0 to 80.1 ± 15.5 for Pain, from 84.5 ± 16.8 to 88.1 ± 14.2 for ADL, and from 44.2 ± 28.3 to 49.1 ± 28.5 for Sport/Rec. CONCLUSIONS: Patients undergoing isolated ACLR and those undergoing ACLR with additional MM and/or LM resection or repair obtained equivalent results for each of the KOOS subscales at the 1- and 2-year postoperative follow-up assessments. Differences between the groups were only detectable preoperatively, with patients undergoing ACLR and MM plus LM repair showing the lowest scores for the KOOS Symptoms, Pain, ADL, and Sport/Rec subscales. LEVEL OF EVIDENCE: Level III, retrospective comparative therapeutic trial.

One sixth of primary anterior cruciate ligament reconstructions may undergo reoperation due to complications or new injuries within 2 years.

PURPOSE: To analyse the incidence, types and risk factors for reoperation within 2 years of primary anterior cruciate ligament reconstruction (ACLR). METHODS: Our clinic registry was used to identify primary ACLRs, performed from 2005 to 2015, and reoperations performed on the ipsilateral knee within 2 years at our institution. Reoperations were identified using procedural codes and analysis of medical records. A logistic regression analysis was used to evaluate risk factors for reoperation. RESULTS: A total of 6030 primary ACLRs were included. A total of 1112 (18.4%) reoperations performed on 1018 (16.9%) primary ACLRs were identified. The most common reoperations were screw removal (n = 282, 4.7%), meniscus procedures (n = 238, 3.9%), cyclops removal/notchplasty (n = 222, 3.7%) and reoperations due to graft rupture (n = 146, 2.4%), including revision ACLR. Age < 30 years (OR 1.57; 95% CI 1.37-1.80; P < 0.001), female gender (OR 1.33; 95% CI 1.17-1.51; P < 0.001), medial meniscus repair (OR 1.55; 95% CI 1.23-1.97; P < 0.001), lateral meniscus resection (OR 1.26; 95% CI 1.07-1.49; P = 0.005) and lateral meniscus repair (OR 1.38; 95% CI 1.03-1.85; P = 0.02) at primary ACLR were found to be risk factors for reoperation. CONCLUSION: One sixth of all primary ACLRs underwent reoperation due to complications or new injuries within 2 years. The most common reoperations were screw removal, meniscus procedures, cyclops removal/notchplasty and reoperations due to graft rupture, including revision ACLR. Younger age (< 30 years), female gender, medial meniscus repair and lateral meniscus resection or repair at primary ACLR were associated with an increased risk of reoperation. This study provides clinicians with important data to inform patients about the short-term reoperation rates, the most common reoperation procedures and risk factors for reoperation after primary ACLR. LEVEL OF EVIDENCE: III.

Age, gender, quadriceps strength and hop test performance are the most important factors affecting the achievement of a patient-acceptable symptom state after ACL reconstruction.

PURPOSE: To assess the percentage of patients achieving an acceptable symptom state 2 years after primary anterior cruciate ligament reconstruction (ACLR) and to identify factors affecting its achievement, in a large cohort. METHODS: Patients who underwent primary ACLR at Capio Artro Clinic, Stockholm, Sweden, from 2005 to 2015, were identified in our clinic registry. Patients who had completed the Knee injury and Osteoarthritis Outcome Score (KOOS) at the 2-year follow-up were included. The primary outcome was the achievement of a patient-acceptable symptom state (PASS) for each KOOS subscale. A multivariate logistic regression analysis was used to determine whether patient age, gender, time from injury to surgery, pre-injury Tegner activity level, graft type, cartilage injury, the presence of medial meniscus (MM) or lateral meniscus (LM) resection or repair and the recovery of 6-month symmetrical (limb symmetry index [LSI] of ≥ 90%) isokinetic quadriceps or hamstring strength and single-leg-hop test performance were factors associated with the achievement of a PASS for each KOOS subscale. RESULTS: A total of 2335 primary ACLRs were included. More than 60% of the patients reported a PASS on four of the five KOOS subscales. Age ≥ 30 years and an LSI of ≥ 90% for 6-month isokinetic quadriceps strength increased the odds of achieving a PASS across all KOOS subscales. Female gender reduced the odds of achieving a PASS on the Pain (OR 0.76; 95% CI 0.62-0.94; P = 0.01), activities of daily living (ADL) (OR 0.79; 95% CI 0.64-0.97; P = 0.02) and sport and recreation (OR 0.72; 95% CI 0.58-0.89; P = 0.003) subscales. The presence of an MM repair reduced the odds of achieving a PASS on the Pain (OR 0.59; 95% CI 0.36-0.96; P = 0.03) subscale. Hamstring tendon (HT) autograft rather than bone-patellar tendon-bone (BPTB) autograft showed increased odds (OR 2.02; 95% CI 1.31-3.10; P = 0.001), whereas a cartilage injury showed reduced odds (OR 0.73; 95% CI 0.55-0.97; P = 0.03) of achieving a PASS on the sport and recreation subscale. An LSI of ≥ 90% for 6-month single-leg-hop test performance increased the odds of achieving a PASS on the ADL (OR 1.37; 95% CI 1.09-1.71; P = 0.005), Sport and Recreation (OR 1.40; 95% CI 1.11-1.77; P = 0.004), and quality of life (OR 1.28; 95% CI 1.00-1.63; P = 0.04) subscales. CONCLUSION: More than 60% of the patients reported an acceptable symptom state on four of the five KOOS subscales 2 years after primary ACLR. Age ≥ 30 years and female gender were the non-modifiable factors that consistently increased and reduced, respectively, the odds of achieving a PASS. A symmetrical 6-month isokinetic quadriceps strength and single-leg-hop test performance were the modifiable factors that consistently increased the opportunity of achieving a PASS 2 years after primary ACLR. LEVEL OF EVIDENCE: III.

There is no general use of thromboprophylaxis and prolonged antibiotic prophylaxis in anterior cruciate ligament reconstruction: a nation-wide survey of ACL surgeons in Sweden.

PURPOSE: The use of prophylaxis for thromboembolism and infection in anterior cruciate ligament (ACL) reconstruction is not well documented and no general guidelines have been established. The aim of this study was to evaluate the ACL surgeons' individual strategies of thromboprophylaxis, use of prolonged antibiotic prophylaxis and vancomycin-soaked ACL grafts, and if its use is supported in the current literature. Additionally, the rationale for use of tourniquet was analysed. METHODS: Questionnaires were distributed to all Swedish ACL surgeons who are registered in the Swedish Knee Ligament Register (SKLR), asking about prescription of thromboprophylaxis, prolonged antibiotic prophylaxis, the use of vancomycin-soaked graft and the use of a tourniquet during surgery. The responses were assessed for agreement and the thromboprophylaxis data were analysed in relation to the 2016 SKLR data. RESULTS: 115 (75%) ACL surgeons responded to the survey. 81.7% prescribed thromboprophylaxis only when risk factors, such as history of thrombosis and the use of oral contraceptives, were present. Female gender, older age and admitted patient were considered the risk factors with the lowest impact. The respondents were generally restrictive regarding the use of prolonged antibiotic prophylaxis. The use of vancomycin-soaked graft was used by only nine (8%) surgeons representing 406 (13%) of the surgeries. CONCLUSION: Swedish ACL surgeons are generally restrictive using thromboprophylaxis and only when risk factors are present. However, there is a lack of consensus in how to weigh the different risk factors and it does not completely adhere to the existing literature. Prolonged antibiotic prophylaxis is rarely used and the use of vancomycin soaking of graft is very limited and applies only to a small number of surgeons. The use of tourniquet is common. There is a need for ACL-specific guidelines regarding the use of thromboprophylaxis. LEVEL OF EVIDENCE: IV.

National injury prevention measures in team sports should focus on knee, head, and severe upper limb injuries.

PURPOSE: To examine acute injuries in licensed floorball, football, handball, and ice hockey players in all ages nationwide in Sweden, and to identify the most common and severe injuries in each body location and recommend injury prevention measures. METHODS: Using national sport insurance data from years 2006-2015 was the incidence and proportion of acute injuries, and injuries leading to permanent medical impairment (PMI), calculated in the four team sports. The most common injury type and injured body part was identified, with a particular focus of the severe injuries. Comparison between sexes was made. RESULTS: In total, there were 92,162 registered injuries in all sports together. Knee injuries were most common, and also had the highest incidence of PMI, in all ball sports and in female ice hockey players. In male ice hockey, the most common injury was a dental and face injury, and PMI injuries were mostly in the shoulder. The most severe PMI injuries were rare and most often a face/eye injury in male floorball and ice hockey, a concussion in female ice hockey, and a knee injury in female floorball, and in both sexes in football and handball. CONCLUSIONS: To achieve the greatest impact in reducing the adverse effects of acute sport injuries nationwide in Sweden, preventive measures should focus on knee injuries in all the investigated team sports. The severe head/face and upper limb injuries also need attention. Protective equipment, neuromuscular training programs, rules enforcements, and fair-play interventions may reduce the incidence of injuries.

Revision anterior cruciate ligament reconstruction restores knee laxity but shows inferior functional knee outcome compared with primary reconstruction.

PURPOSE: To evaluate and compare knee laxity and functional knee outcome between primary and revision anterior cruciate ligament (ACL) reconstruction in the same cohort of patients. METHODS: Patients who underwent primary and revision ACL reconstruction (ACLR) at Capio Artro Clinic, Stockholm, Sweden, from 2000 to 2015, were identified in our local database. Inclusion criteria were: same patients who underwent primary hamstring tendons (HT) and revision bone-patellar tendon-bone (BPTB) autograft ACLR, no associated ligament injuries and no contralateral ACL injuries/reconstructions. The cause of revision ACLR was graft rupture for all patients. The KT-1000 arthrometer, with an anterior tibial load of 134-N, was used to evaluate knee laxity preoperatively and 6-month postoperatively. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at the 1-year follow-up. RESULTS: A total of 118 patients with primary and revision ACLR arthrometric laxity measurements were available (51.0% males; mean age at primary ACLR 21.7 ± 7.1 years and revision ACLR 24.3 ± 7.5 years). The mean preoperative and postoperative anterior side-to-side (STS) difference values were not significantly different between primary and revision ACLR. However, primary ACLR showed a significantly higher frequency of postoperative anterior STS difference > 5 mm compared with revision ACLR (8.4 vs 5.0%; P = 0.02). The KOOS was available for primary and revision ACLR for 73 patients (55.4% males; mean age at primary ACLR 21.6 ± 7 years and revision ACLR 24.7 ± 7.3 years). Preoperatively, revision ACLR showed significantly higher scores in all KOOS subscales, except for the activity of daily living (ADL) subscale. For the primary ACLR, the improvement from preoperatively to the 1-year follow-up was significantly greater in all KOOS subscales and, the postoperative scores were superior for Pain, ADL and Sports subscales compared with revision ACLR. CONCLUSIONS: The findings of this study showed that anterior knee laxity is restored with revision BPTB autograft ACLR after failed primary HT autograft ACLR, in the same cohort of patients. However, revision ACLR showed a significantly inferior functional knee outcome compared with primary ACLR. It is important for clinicians to inform and set realistic expectations for patients undergoing revision ACLR. Patients must be aware of the fact that having revision ACLR their knee function will not improve as much as with primary ACLR and the final postoperative functional outcome is inferior. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

Only one patient out of five achieves symmetrical knee function 6 months after primary anterior cruciate ligament reconstruction.

PURPOSE: To assess the percentage of patients achieving symmetrical knee function 6 months after primary anterior cruciate ligament (ACL) reconstruction (ACLR) and to identify factors affecting its achievement, in a large cohort. METHODS: Data were extracted from our clinic database. Patients who underwent primary ACLR from 2000 to 2015 and were assessed with the isokinetic quadriceps and hamstring muscles strength tests and single-leg-hop test at the 6-month follow-up were included in the study. Demographic data, information on the graft used, cartilage injuries and concomitant meniscal surgery were reviewed. Patients who reached a limb symmetry index (LSI) of ≥ 90% in all three tests were considered to have achieved symmetrical knee function. A multivariate logistic regression analysis was used to determine whether patient age, gender, time from injury to surgery, pre-injury Tegner activity level, graft type, cartilage injury and the presence of medial meniscus (MM) or lateral meniscus (LM) resection or repair were factors associated with the achievement of symmetrical knee function 6 months after primary ACLR. RESULTS: A total of 4093 patients (54.3% males) with a mean age of 28.3 ± 10.7 years were included. Data from all three tests were available for 3541 patients. The proportion of patients that achieved a LSI of ≥ 90% was 35.7%, 47.3% and 67.9% for isokinetic quadriceps muscle strength, hamstring muscles strength and the single-leg-hop test, respectively. A total of 693 patients (19.6%) achieved symmetrical knee function, reaching a LSI of ≥ 90% in all three tests. Older age (≥ 30 years) (OR, 0.50; 95% CI 0.41-0.61; P < 0.001), MM resection (OR, 0.75; 95% CI 0.57-0.98; P = 0.03) and MM repair (OR, 0.63; 95% CI 0.40-0.98; P = 0.04) reduced the odds, whereas the use of hamstring tendon (HT) autograft (OR, 2.28; 95% CI 1.51-3.45; P < 0.001) over bone-patellar tendon-bone (BPTB) autograft increased the odds of achieving symmetrical knee function. CONCLUSION: Only 19.6% of the patients achieved symmetrical knee function 6 months after primary ACLR. Age ≥ 30 years, MM resection and MM repair reduced the chance, whereas the use of HT autograft over BPTB autograft increased the chance of achieving symmetrical knee function 6 months after primary ACLR. This study shows that most of the patients are yet to regain symmetrical knee function 6 months after primary ACLR and, moreover, it identifies several factors affecting its achievement in a large cohort. The results of this study should be used to counsel patients about their expected functional recovery and to optimize rehabilitation and maximize knee function after ACLR. LEVEL OF EVIDENCE: III.

Increased knee laxity with hamstring tendon autograft compared to patellar tendon autograft: a cohort study of 5462 patients with primary anterior cruciate ligament reconstruction.

PURPOSE: To compare anterior knee laxity and patient-reported outcome measures (PROMs) between anterior cruciate ligament reconstruction (ACLR) performed with bone-patellar tendon-bone (BPTB) and hamstring tendon (HT) autografts and, moreover, to study any correlation between postoperative anterior knee laxity and PROMs. METHODS: Patients who underwent primary ACLR at Capio Artro Clinic, Stockholm, Sweden, from January 2000 to October 2015, were identified in our local database. Instrumented laxity measurements and PROMs were reviewed. The KT-1000 arthrometer, with an anterior tibial load of 134-N, was used to evaluate knee laxity preoperatively and at the 6-month follow-up. The Lysholm score was collected preoperatively and at 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at the 1-year follow-up. RESULTS: A total of 5462 primary ACLRs, 692 BPTBs and 4770 HT autografts were included in the study. All the patients showed a significant reduction in knee laxity from preoperatively to postoperatively (BPTB group: from 3.8 ± 2.6 to 1.2 ± 2.1 mm; HT group: from 3.6 ± 3.1 to 1.8 ± 2.2 mm; P < 0.001 for both). The HT group showed a significantly increased postoperative knee laxity compared with the BPTB group (1.8 ± 2.2 vs 1.2 ± 2.1 mm; P < 0.001). The mean anterior tibial translation (ATT) reduction from preoperative to postoperative was significantly larger for the BPTB graft compared with the HT graft (2.7 ± 2.2 vs 1.7 ± 2.6 mm; P < 0.001). A significantly higher rate of "surgical failures", defined as a postoperative side-to-side (STS) difference > 5 mm, was found in the HT group compared with the BPTB group at follow-up (4.3 vs 2.4%; P < 0.001). A significantly larger improvement was found in the HT group compared with the BPTB group for the KOOS Pain (9.5 vs 8.0; P = 0.02), Activities of Daily Living (7.2 vs 5.7; P = 0.006), Sports (24.2 vs 15.3; P < 0.001) and Quality of Life (25.8 vs 22.1; P = 0.001) subscales. No significant difference regarding the mean improvement in the Lysholm knee score was found between the two grafts (BPTB group: 14.5, HT group: 14.0; n.s.). No correlation between postoperative anterior knee laxity and PROMs was found in either graft group. CONCLUSION: Primary ACLR performed with HT autograft resulted in greater postoperative anterior knee laxity and significantly more surgical failures (STS > 5 mm) compared with BPTB autograft. The BPTB autograft showed a larger anterior knee laxity reduction (ATT reduction) in conjunction with primary ACLR. The HT autograft led to a significantly larger improvement in four of five KOOS subscales from preoperatively to the 1-year follow-up, compared with BPTB autograft. There was no association between postoperative anterior knee laxity and PROMs for either graft. The findings of the present study provide clinicians with valuable information regarding differences in knee laxity and subjective knee function between BPTB and HT autograft after primary ACLR. The use of BPTB autograft should be considered for patients with high knee stability demands. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.