Influence of Surgeon Experience and Clinic Volume on Subjective Knee Function and Revision Rates in Primary ACL Reconstruction: A Study from the Swedish National Knee Ligament Registry

Background

Anterior cruciate ligament reconstruction (ACLR) performed by high-volume surgeons/clinics has been associated with increased graft individualization and decreased operating times, complication rates, and total costs.

Purpose

To investigate the influence of surgeon/clinic volume on subjective knee function and revision surgery rates at 2 years after primary ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

Data from the Swedish National Knee Ligament Registry were used to study patients who underwent primary ACLR between 2008 and 2019. Surgeons/clinics were categorized based on a combination of total caseload volume (cutoff: 50 ACLRs/surgeon, 500 ACLRs/clinic) and annual volume (cutoff: 29 ACLRs/year/surgeon, 56 ACLRs/year/clinic). The thresholds of minimal important change (MIC), Patient Acceptable Symptom State (PASS), and treatment failure (TF) relative to the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS4 (mean score of the KOOS Pain, Symptoms, Sports/Rec, and QoL subscales) were applied. Adjusted multivariable logistic regression was performed to assess variables influencing the MIC, PASS, or TF of the KOOS and KOOS4. Adjusted Cox regression analysis was conducted to determine the hazard ratio of subsequent ACLR.

Results

Of 35,371 patients, 16,317 had 2-year follow-up outcome data and were included. Patients who underwent primary ACLR by high-volume surgeons had significantly higher MIC and PASS rates and lower TF rates when compared with patients who underwent the procedure by low-volume surgeons: MICKOOS4: 70.6% vs 66.3%; PASSKOOS4: 46.0% versus 38.3%; and TFKOOS4: 8.7% versus 11.8% (all P < .02). Significantly decreased odds of achieving MICKOOS4 (OR, 0.74; 95% CI, 0.62-0.88) and PASSKOOS4 (OR, 0.71; 95% CI, 0.60-0.84) were found for ACLRs performed by low-volume surgeons. Clinic volume did not influence the odds of reaching MIC, PASS, or TF. Overall, 804 patients (2.3%) underwent subsequent ACLR at <2 years, with significantly higher revision rates among patients operated on at high-volume clinics (2.5% vs 1.7%; P < .001). However, in the adjusted Cox regression, surgeon/clinic volume had no influence on subsequent ACLR rates. High-volume surgeons/clinics had decreased time to surgery, operating time, perioperative complication rates, and use of thromboprophylaxis and nonroutine antibiotics (P < .001).

Conclusion

Patients who underwent primary ACLR by high-volume surgeons experienced increased improvement and satisfaction regarding subjective knee function. Factors other than surgical volume influenced subsequent surgery rates. Patients might benefit from undergoing primary ACLR by high-volume providers.

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.

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.

Neurodegenerative disease among male elite football (soccer) players in Sweden: a cohort study

BACKGROUND

Football (soccer) players might be at increased risk of neurodegenerative disease, which has led to questions regarding the safety of the sport and recent measures introduced by football associations to reduce heading of the ball. We aimed to assess the risk of neurodegenerative disease among male football players in the Swedish top division Allsvenskan, compared with matched controls.

METHODS

In this cohort study, we identified all male football players (amateurs and professionals) who had played at least one game in Allsvenskan from Aug 1, 1924 to Dec 31, 2019 and excluded players whose personal identity number could not be retrieved or be identified in the Total Population Register, and those who were not born in Sweden and who had immigrated to the country after age 15 years. Football players were matched with up to ten controls from the general population according to sex, age, and region of residence. We used nationwide registers to compare the risk of neurodegenerative disease (diagnoses recorded in death certificates, during hospital admissions and outpatient visits, or use of prescription drugs for dementia) among football players versus controls. We also assessed each type of neurodegenerative disease (Alzheimer's disease and other dementias, motor neuron disease, and Parkinson's disease) separately, and compared the risk of neurodegenerative disease among outfield players versus goalkeepers.

FINDINGS

Of 7386 football players who had played at least one game in the top Swedish division between Aug 1, 1924, and Dec 31, 2019, 182 players were excluded for an unretrievable personal identity number, and 417 were excluded due to their number not being identified in the Total Population Register. After a further exclusion of 780 players and 11 627 controls who were born outside of Sweden and who had immigrated to the country after age 15 years, 6007 football players (510 goalkeepers) were included in the study population along with 56 168 matched controls. During follow-up to Dec 31, 2020, 537 (8·9%) of 6007 football players and 3485 (6·2%) of 56 168 controls were diagnosed with neurodegenerative disease. The risk of neurodegenerative disease was higher among football players than controls (hazard ratio [HR] 1·46 [95% CI 1·33-1·60]). Alzheimer's disease and other dementias were more common among football players than controls (HR 1·62 [95% CI 1·47-1·78]), significant group differences were not observed for motor neuron disease (HR 1·27 [0·73-2·22]), and Parkinson's disease was less common among football players (HR 0·68 [0·52-0·89]). The risk of neurodegenerative disease was higher for outfield players than controls (HR 1·50 [95% CI 1·36-1·65]) but not for goalkeepers versus controls (HR 1·07 [0·78-1·47]), and outfield players had a higher risk of neurodegenerative disease than did goalkeepers (HR 1·43 [1·03-1·99]). All-cause mortality was slightly lower among football players than controls (HR 0·95 [95% CI 0·91-0·99]).

INTERPRETATION

In this cohort study, male football players who had played in the Swedish top division had a significantly increased risk of neurodegenerative disease compared with population controls. The risk increase was observed for Alzheimer's disease and other dementias but not for other types of neurodegenerative disease, and among outfield players, but not among goalkeepers. Our study expands on the data that can be used to assess and manage risks in the sport.

FUNDING

Karolinska Institutet, The Swedish Research Council for Sport Science, Folksam Research Foundation, Hedberg Foundation, Neurofonden, and Åhlen Foundation.

Alcohol related disorders among elite male football players in Sweden: nationwide cohort study

OBJECTIVES

To assess whether male elite football players are at increased risk of alcohol related disorders compared with men from the general population, and whether such an increased risk would vary on the basis of calendar year of the first playing season in the top tier of competition, age, career length, and goal scoring abilities.

DESIGN

Nationwide cohort study.

SETTING

Sweden, 1924-2020.

PARTICIPANTS

6007 male football players who had played in the Swedish top division, Allsvenskan, from 1924 to 2019 and 56 168 men from the general population matched to players based on age and region of residence.

MAIN OUTCOME MEASURES

Primary outcome was alcohol related disorders (diagnoses recorded in death certificates, during hospital admissions and outpatient visits, or use of prescription drugs for alcohol addiction); secondary outcome was disorders related to misuse of other drugs.

RESULTS

During follow-up up to 31 December 2020, 257 (4.3%) football players and 3528 (6.3%) men from the general population received diagnoses of alcohol related disorders. In analyses accounting for age, region of residence, and calendar time, risk of alcohol related disorders was lower among football players than among men from the general population (hazard ratio 0.71, 95% confidence interval 0.62 to 0.81). A reduced risk of alcohol related disorders was observed for football players who played their first season in the top tier in the early 1960s and later, while no significant difference versus men from the general population was seen in the risk for football players from earlier eras. The hazard ratio was lowest at around age 35 years, and then increased with age; at around age 75 years, football players had a higher risk of alcohol related disorders than men from the general population. No significant association was seen between goal scoring, number of games, and seasons played in the top tier and the risk of alcohol related disorders. Risk of disorders related to other drug misuse was significantly lower among football players than the general population (hazard ratio 0.22, 95% confidence interval 0.15 to 0.34).

CONCLUSIONS

In this nationwide cohort study, male football players who had played in the Swedish top tier of competition had a significantly lower risk of alcohol related disorders than men from the general population.

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.

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.

Effect of Concomitant Meniscal Lesions and Meniscal Surgery in ACL Reconstruction With 5-Year Follow-Up: A Nationwide Prospective Cohort Study From Norway and Sweden of 8408 Patients

Background

Increased knowledge of the factors predicting outcome after anterior cruciate ligament reconstruction (ACLR) is needed.

Purpose

To determine the effect of concomitant meniscal lesions, and the surgical management thereof, on patient-reported outcomes 5 years after ACLR.

Study Design

Prospective cohort study; Level of evidence, 2.

Methods

A total of 15,706 patients who underwent primary unilateral ACLR between 2005 and 2008 were enrolled prospectively and evaluated longitudinally. All patients were part of the Norwegian and Swedish national knee ligament registries. Outcomes at 5-year follow-up were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS). A multivariable linear regression model was used to assess possible effects on prognosis, as measured by KOOS, of a concomitant meniscal lesion and its associated surgical treatment.

Results

At a mean follow-up of 5.1 ± 0.2 years, KOOS data were available from 8408 patients: 4774 (57%) patients with no and 3634 (43%) patients with concomitant meniscal lesions (mean patient age, 33.8 ± 10.7 years). Patients with concomitant meniscal lesions reported equal crude mean scores compared with patients without meniscal lesions in all KOOS subscales 5 years after ACLR. The mean improvement in scores from preoperative to the 5-year follow-up was greater for patients with a concomitant meniscal lesion for the KOOS Pain, Activities of Daily Living (ADL), and Sport and Recreation subscales. In the adjusted regression analyses, using patients without concomitant meniscal lesions as the reference, neither no treatment nor resection or repair of medial meniscal lesions were significantly associated with KOOS scores 5 years after ACLR. Except for the ADL subscale, in which a repaired lateral meniscal lesion was associated with better outcome, no significant associations between any of the lateral meniscal lesion treatment categories and KOOS outcome at 5-year follow-up were identified.

Conclusion

Concomitant meniscal lesions at the time of ACLR conferred no negative effects on patient-reported outcomes 5 years after ACLR. The improvement in selected KOOS subscales from preoperative to the 5-year follow-up was significantly greater for patients with concomitant meniscal lesions than for patients without such lesions.

Risk Factors for Septic Arthritis After Anterior Cruciate Ligament Reconstruction: A Nationwide Analysis of 26,014 ACL Reconstructions

BACKGROUND

Septic arthritis (SA) after anterior cruciate ligament reconstruction (ACLR) is a rare yet severe complication. The samples in previous studies have been small and without nationwide coverage, making analysis uncertain with a risk of bias. Conclusions to recommend preventive measures are therefore difficult to draw, and it has not been possible to perform a comprehensive risk factor analysis.

PURPOSE

To study the incidence of SA after ACLR in a large, nationwide population and to study the risk factors for SA after ACLR.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

All ACLRs, primary and revision, in the Swedish Knee Ligament Registry between 2006 and 2013 were linked with data from the Swedish National Board of Health and Welfare. The incidence of SA events was determined using entries from the day of surgery until 90 days postoperatively based on diagnosis codes and the prescription of antibiotics. All events of SA were verified via a review of medical records. Risk factors were analyzed based on data from the registries. Descriptive statistics were used to describe the findings, while logistic regression analysis was used for the risk analysis.

RESULTS

The cohort consisted of 26,014 primary and revision ACLRs. During the study period, 298 events of SA (1.1%) were identified. The high-volume units (≥500 ACLRs during the study period) had a distribution of SA between 2 and 47 (0.2%-2.9%). Independent risk factors of SA were male sex (OR, 1.65; 95% CI, 1.28-2.13), operating time ≥70 minutes (OR, 1.83; 95% CI, 1.42-2.36), hamstring tendon autograft (OR, 2.23; 95% CI, 1.21-4.08), and clindamycin as perioperative antibiotic prophylaxis (OR, 1.94; 95% CI, 1.10-3.41).

CONCLUSION

The incidence of SA after ACLR in this nationwide cohort was 1.1%. Male sex, hamstring tendon autografts, and a longer operating time were all independent risk factors for SA. The use of clindamycin as perioperative antibiotic prophylaxis was a risk factor compared with the use of cloxacillin. Some high-volume units had a very low infection rate (0.2%).

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.

Can Talented Youth Soccer Players Who Have Undergone Anterior Cruciate Ligament Reconstruction Reach the Elite Level?

BACKGROUND

Anterior cruciate ligament (ACL) ruptures are common in soccer players, and reconstructive surgery is often performed to restore knee stability and enable a return to play.

PURPOSE

To investigate whether an ACL reconstruction for talented youth soccer players affects their potential to become elite players at the senior level.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All soccer players who participated in the Swedish National Elite Camp for 15-year-old players between 2005 and 2011 (N = 5285 players; 2631 boys and 2654 girls) were matched with the Swedish National Knee Ligament Registry to identify the players who had undergone ACL reconstruction. Information on player participation in Swedish league games and level of play was collected from the Swedish Football Association's administrative data system. The players with an ACL reconstruction who were injured at the ages of 15 to 19 years were compared with the rest of the players who participated in the National Elite Camp to see whether an early ACL reconstruction affected whether they remained active as soccer players and their chance to play at the elite level as seniors.

RESULTS

A total of 524 (9.9%) players had undergone an ACL reconstruction, and 292 (5.5%; 75 male and 217 female) had sustained their injury at age 15 to 19 years. During the follow-up period, 122 (23.3%) players underwent ACL reconstruction: revision (11.5%; n = 60) or contralateral (11.8%; n = 62). Male and female soccer players undergoing an ACL reconstruction at age 15 to 19 years experienced no significant effect on being active or playing at the elite level in the season that they turned 21 years old. Of the youth players who underwent ACL reconstruction, 12% of the male players and 11.5% of the female players progressed to the elite level at the age of 21 years compared with 10.3% of the men and 11.1% of the women among the uninjured players.

CONCLUSION

ACL reconstructive surgery in talented youth soccer players offers them the opportunity to become elite players as seniors and permits an activity level on a par with that of their uninjured peers. However, almost 1 in 4 requires further ACL surgery, so the players' future knee health should be considered when deciding on a return to play.

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.

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.

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.

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.

Deep venous thrombosis and pulmonary embolism after anterior cruciate ligament reconstruction: incidence, outcome, and risk factors

AIMS

The aim of this study was to investigate the incidence, risk factors, and outcome of venous thromboembolism (VTE) following anterior cruciate ligament (ACL) reconstruction in a nationwide cohort.

PATIENTS AND METHODS

All ACL reconstructions, primary and revision, that were recorded in the Swedish Knee Ligament Register (SKLR) between 2006 and 2013 were linked with data from the Swedish National Board of Health and Welfare. The incidence of VTE was determined by entries between the day of surgery until 90 days postoperatively based on diagnosis codes and the prescription of anticoagulants. Risk factors, outcome, and the use of thromboprophylaxis were analyzed. Descriptive statistics with multivariate analysis were used to describe the findings.

RESULTS

The cohort consisted of 26 014 primary and revision ACL reconstructions. There were 89 deep venous thromboses (DVTs) and 12 pulmonary emboli (PEs) with a total of 95 VTEs (0.4 %). Six patients with a PE had a simultaneous DVT. The only independent risk factor for VTE was age greater than or equal to 40 years (odds ratio 2.31, 95% confidence interval 1.45 to 3.70; p < 0.001). Thromboprophylaxis was prescribed to 9461 patients (36%) and was equally distributed between those with and those without a VTE (37.9% vs 36.4%). All patient-reported outcome measures (PROMs) one and two years postoperatively were significantly lower in those with VTE.

CONCLUSION

The incidence of VTE following ACL reconstruction is 0.4%, and the only significant risk factor is age. Patients with VTE had worse postoperative clinical outcome than patients without VTE. We recommend against the routine use of thromboprophylaxis, but it should be considered in older patients.

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.

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.

A Nationwide Follow-up Survey on the Effectiveness of an Implemented Neuromuscular Training Program to Reduce Acute Knee Injuries in Soccer Players

Background:

A cruciate ligament (CL) injury is a severe injury in soccer. Neuromuscular training programs have a well-documented preventive effect, but there are few studies on the effectiveness of such a program at a national level. The Swedish Knee Control Program (KCP) was found to be effective in preventing CL injuries in youth female soccer players. The KCP was implemented nationwide in Sweden in 2010.

Purpose:

To evaluate the effectiveness of the Swedish KCP in reducing acute knee injuries in soccer players at a nationwide level.

Study Design:

Descriptive epidemiology study.

Methods:

All licensed soccer players in Sweden are covered by the same insurance company. Using this insurance database, around 17,500 acute knee injuries that were reported to the insurance company between 2006 and 2015 were included in the study. By matching the number of licensed soccer players with the number of reported injuries each year, the annual incidence of knee and CL injuries was able to be calculated. To evaluate the spread of the KCP nationally, a questionnaire was sent to all 24 Swedish district football associations (FAs) with questions regarding KCP education. The number of downloads of the KCP mobile application (app) was obtained.

Results:

The incidence of CL injuries decreased during the study period for both male (from 2.9 to 2.4 per 1000 player-years) and female players (from 4.9 to 3.9 per 1000 player-years). The overall incidence of knee injuries decreased in both male (from 5.6 to 4.6 per 1000 player-years) and female players (from 8.7 to 6.4 per 1000 player-years). Comparing before and after the nationwide implementation of the KCP, there was a decrease in the incidence of CL injuries by 6% (rate ratio [RR], 0.94 [95% CI, 0.89-0.98]) in male players and 13% (RR, 0.87 [95% CI, 0.81-0.92]) in female players and a decrease in the incidence of knee injuries by 8% (RR, 0.92 [95% CI, 0.89-0.96]) and 21% (RR, 0.79 [95% CI, 0.75-0.83]), respectively (P < .01 for all). This trend corresponded to a reduction of approximately 100 CL injuries each year in Sweden. A total of 21 of 24 district FAs held organized KCP educational courses during the study period. The percentage of district FAs holding KCP courses was between 46% and 79% each year. There were 101,236 downloads of the KCP app.

Conclusion:

The KCP can be considered partially implemented nationwide, and the incidence of knee and CL injuries has decreased in both sexes at a nationwide level.

Meniscal repair results in inferior short-term outcomes compared with meniscal resection: a cohort study of 6398 patients with primary anterior cruciate ligament reconstruction

PURPOSE

To compare patient reported outcome measures (PROMs) during the first postoperative year between isolated anterior cruciate ligament (ACL) reconstruction and ACL reconstruction with concomitant meniscal intervention.

METHODS

Patients who underwent primary ACL reconstruction at Capio Artro Clinic, Stockholm, Sweden, between 1st Jan 2001 and 31st Dec 2014 without concomitant injuries others than meniscal and/or cartilage lesions were included. Five groups of meniscal treatment simultaneously to ACL reconstruction were established; medial meniscal (MM) resection, MM repair, lateral meniscal (LM) resection, LM repair, and MM + LM resection. Patients treated with isolated ACL reconstruction formed a separate group. Preoperative, 6-month and 1-year Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm knee score and Tegner Activity scale were collected. Differences in the change over time were analyzed with an ANOVA for repeated measurements with age at surgery, gender, and cartilage injury as covariates. A univariate ANOVA was applied to analyze PROMs between groups at the final follow-up.

RESULTS

A total of 6398 patients were included (56.8% males, mean age 28.5 ± 10.2 years). The KOOS improved across all subscales for all treatment groups. The mean change over time differed significantly between groups for the subscales symptoms (p = 0.017) and activities in daily living (ADL) (p < 0.001). Symptoms was least improved in the MM repair group, while the MM + LM resection group showed the largest improvement. For the ADL subscale, the isolated ACL reconstruction group showed the least improvement and the MM + LM resection group showed the major improvement. At 1-year follow-up, a significant difference between the groups was found for the subscale symptoms (p = 0.019), where the MM repair group reported the lowest score [mean 78.4 (95% CI 76.3-80.5)]. No significant differences were found between groups in change of the Lysholm score over time; however, at 6 months, the difference between groups was significant (p = 0.006) with the meniscal repair groups reporting the lowest scores.

CONCLUSION

Patients with concomitant meniscal resection are able to reach the same subjective knee function as isolated ACL reconstructions as early as 6 months postoperatively. However, patients with meniscal repair may have slightly worse subjective knee function at both 6- and 12-month follow-up. These findings could help clinicians to set realistic short-term expectations for patients undergoing ACL reconstruction with simultaneous meniscal intervention.

LEVEL OF EVIDENCE

3.

A Controlled Comparison of Microfracture, Debridement, and No Treatment of Concomitant Full-Thickness Cartilage Lesions in Anterior Cruciate Ligament-Reconstructed Knees: A Nationwide Prospective Cohort Study From Norway and Sweden of 368 Patients With 5-Year Follow-up

Background

The effect of microfracture (MF) or surgical debridement of concomitant full-thickness cartilage lesions in anterior cruciate ligament-reconstructed knees on patient-reported outcomes remains to be determined.

Purpose

To evaluate the effect of debridement or MF compared with no surgical treatment of concomitant full-thickness cartilage lesions on patient-reported outcomes 5 years after anterior cruciate ligament reconstruction (ACLR).

Study Design

Cohort study; Level of evidence, 2.

Methods

Included in this study were 644 patients who were registered in the Norwegian and the Swedish National Knee Ligament Registries from 2005 to 2008 as having undergone unilateral primary ACLR and having a concomitant full-thickness cartilage lesion (International Cartilage Repair Society [ICRS] grades 3-4). Of these patients, 129 were treated with debridement, 164 were treated with MF, and 351 received no surgical treatment simultaneously with ACLR. At 5-year follow-up, 368 (57%) patients completed results on the Knee injury and Osteoarthritis Outcome Score (KOOS). Multivariable linear regression was used to estimate the effect of surgical debridement or MF of concomitant full-thickness cartilage lesions on patient-reported outcomes 5 years after ACLR.

Results

Compared with no surgical treatment, there were no unadjusted or adjusted effects of debridement or MF of concomitant full-thickness cartilage lesions on KOOS scores at 5-year follow-up.

Conclusion

Compared with leaving concomitant full-thickness cartilage lesions untreated at the time of ACLR, debridement and MF showed no effect on patient-reported outcomes 5 years after surgery.

Effect of Concomitant Cartilage Lesions on Patient-Reported Outcomes After Anterior Cruciate Ligament Reconstruction: A Nationwide Cohort Study From Norway and Sweden of 8470 Patients With 5-Year Follow-up

Background:

The effect of concomitant focal cartilage lesions on patient-reported outcomes after anterior cruciate ligament reconstruction (ACLR) remains to be determined.

Purpose:

To evaluate the effect of concomitant partial-thickness (International Cartilage Repair Society [ICRS] grades 1-2) and full-thickness (ICRS grades 3-4) cartilage lesions on patient-reported outcomes 5 years after ACLR.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

All patients who underwent unilateral primary ACLR registered in the Norwegian and Swedish National Knee Ligament Registries from 2005 to 2008 (n = 15,783) were included in the study. At 5-year follow-up, 8470 (54%) patients completed the Knee injury and Osteoarthritis Outcome Score (KOOS). Multivariable linear regression models were used to estimate the effect of concomitant partial-thickness and full-thickness cartilage lesions on patient-reported outcomes (KOOS) 5 years after ACLR.

Results:

Compared with no concomitant cartilage lesions, both partial-thickness and full-thickness cartilage lesions were indicators of statistically significant adverse effects on the KOOS in the adjusted regression analysis at 5-year follow-up after ACLR.

Conclusion:

ACL-injured patients with concomitant cartilage lesions reported worse outcomes and less improvement than those without cartilage lesions 5 years after ACLR.

Graft fixation influences revision risk after ACL reconstruction with hamstring tendon autografts

Background and purpose - A large number of fixation methods of hamstring tendon autograft (HT) are available for anterior cruciate ligament reconstruction (ACLR). Some studies report an association between fixation method and the risk of revision ACLR. We compared the risk of revision of various femoral and tibial fixation methods used for HT in Scandinavia 2004-2011. Materials and methods - A register-based study of 38,666 patients undergoing primary ACLRs with HT, with 1,042 revision ACLRs. The overall median follow-up time was 2.8 (0-8) years. Fixation devices used in a small number of patients were grouped according to design and the point of fixation. Results - The most common fixation methods were Endobutton (36%) and Rigidfix (31%) in the femur; and interference screw (48%) and Intrafix (34%) in the tibia. In a multivariable Cox regression model, the transfemoral fixations Rigidfix and Transfix had a lower risk of revision (HR 0.7 [95% CI 0.6-0.8] and 0.7 [CI 0.6-0.9] respectively) compared with Endobutton. In the tibia the retro interference screw had a higher risk of revision (HR 1.9 [CI 1.3-2.9]) compared with an interference screw. Interpretation - The choice of graft fixation influences the risk of revision after primary ACLR with hamstring tendon autograft.

Patient demographic and surgical characteristics in anterior cruciate ligament reconstruction: a description of registries from six countries

OBJECTIVE

Findings from individual anterior cruciate ligament reconstruction (ACLR) registry studies are impactful, but how various registries from different countries compare with different patient populations and surgical techniques has not been described. We sought to describe six ACLR registry cohorts to understand variation across countries.

METHODS

Five European registries and one US registry participated. For each registry, all primary ACLR registered between registry establishment through 31December 2014 were identified. Descriptive statistics included frequencies, proportions, medians and IQRs. Revision incidence rates following primary ACLR were computed.

RESULTS

101 125 ACLR were included: 21 820 in Denmark, 300 in Luxembourg, 17 556 in Norway, 30 422 in Sweden, 2972 in the UK and 28 055 in the US. In all six cohorts, males (range: 56.8%-72.4%) and soccer injuries (range: 14.1%-42.3%) were most common. European countries mostly used autografts (range: 93.7%-99.7%); allograft was most common in the US (39.9%). Interference screw was the most frequent femoral fixation in Luxembourg and the US (84.8% and 42.9%), and suspensory fixation was more frequent in the other countries (range: 43.9%-75.5%). Interference was the most frequent tibial fixation type in all six cohorts (range: 64.8%-98.2%). Three-year cumulative revision probabilities ranged from 2.8% to 3.7%.

CONCLUSIONS

Similarities in patient demographics and injury activity were observed between all cohorts of ACLR. However, graft and fixation choices differed. Revision rates were low. This work, including >100 000 ACLR, is the most comprehensive international description of contemporary practice to date.

2018 International Olympic Committee Consensus Statement on Prevention, Diagnosis, and Management of Pediatric Anterior Cruciate Ligament Injuries

In October 2017, the International Olympic Committee hosted an international expert group of physical therapists and orthopaedic surgeons who specialize in treating and researching pediatric anterior cruciate ligament (ACL) injuries. The purpose of this meeting was to provide a comprehensive, evidence-informed summary to support the clinician and help children with ACL injury and their parents/guardians make the best possible decisions. Representatives from the following societies attended: American Orthopaedic Society for Sports Medicine; European Paediatric Orthopaedic Society; European Society for Sports Traumatology, Knee Surgery, and Arthroscopy; International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine; Pediatric Orthopaedic Society of North America; and Sociedad Latinoamericana de Artroscopia, Rodilla, y Deporte. Physical therapists and orthopaedic surgeons with clinical and research experience in the field and an ethics expert with substantial experience in the area of sports injuries also participated. This consensus statement addresses 6 fundamental clinical questions regarding the prevention, diagnosis, and management of pediatric ACL injuries. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision making with children and the potential long-term ramifications of the injury.

2018 International Olympic Committee consensus statement on prevention, diagnosis and management of paediatric anterior cruciate ligament (ACL) injuries

In October 2017, the International Olympic Committee hosted an international expert group of physiotherapists and orthopaedic surgeons who specialise in treating and researching paediatric ACL injuries. Representatives from the American Orthopaedic Society for Sports Medicine, European Paediatric Orthopaedic Society, European Society for Sports Traumatology, Knee Surgery & Arthroscopy, International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine, Pediatric Orthopaedic Society of North America and Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte attended. Physiotherapists and orthopaedic surgeons with clinical and research experience in the field, and an ethics expert with substantial experience in the area of sports injuries also participated. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision-making with children and the potential long-term ramifications of the injury. This consensus statement addresses six fundamental clinical questions regarding the prevention, diagnosis and management of paediatric ACL injuries. The aim of this consensus statement is to provide a comprehensive, evidence-informed summary to support the clinician, and help children with ACL injury and their parents/guardians make the best possible decisions.

Medial Meniscus Resection Increases and Medial Meniscus Repair Preserves Anterior Knee Laxity: A Cohort Study of 4497 Patients With Primary Anterior Cruciate Ligament Reconstruction

BACKGROUND

There are still controversies regarding the effects on knee laxity of additional meniscus resection or repair in the setting of anterior cruciate ligament reconstruction (ACLR). Hypothesis/Purpose: The purpose was to determine the effects on knee laxity of resection or repair of medial meniscus (MM) or lateral meniscus (LM) injuries in the ACLR knee. The hypothesis was that patients with an additional meniscus resection would have significantly increased postoperative knee laxity versus that of an isolated ACLR, whereas patients with meniscus repair would have laxity comparable to that of an isolated ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The KT-1000 arthrometer, with an anterior tibial load of 134 N, was used to evaluate knee laxity preoperatively and at 6-month postoperative follow-up for a total of 4497 patients with primary hamstring tendon ACLR. Patients with isolated ACLR or ACLR with additional MM resection, MM repair, LM resection, LM repair, or MM plus LM resection were compared, with the isolated ACLR group as a control.

RESULTS

All patients showed a significant reduction of knee laxity preoperatively (3.6 ± 3.1 mm) to postoperatively (1.9 ± 2.2 mm) ( P < 0.0001). Patients who had an ACLR with either an MM resection (2.2 ± 2.55 mm) or MM + LM resection (2.35 ± 2.30 mm) showed significant increased postoperative knee laxity versus isolated ACLR (1.74 mm ± 2.11 mm) ( P < 0.05), whereas patients with MM repair (1.69 ± 2.37 mm) did not show significantly different knee laxity when compared with the control group ( P > 0.05). LM resection or repair did not significantly affect knee laxity. Significantly more surgical failures, defined as side-to-side difference >5 mm, were found in the ACLR + MM resection group and the ACLR + MM + LM resection group.

CONCLUSION

In ACLR, additional MM resection increased whereas MM repair preserved knee laxity in comparison with the ACLR knee with intact menisci. Neither LM resection or LM repair showed a significant effect on knee laxity. Surgeons should make every effort to repair the meniscus whenever possible to avoid the residual postoperative laxity present in the meniscus-deficient knee.

2018 International Olympic Committee consensus statement on prevention, diagnosis and management of paediatric anterior cruciate ligament (ACL) injuries

In October 2017, the International Olympic Committee hosted an international expert group of physiotherapists and orthopaedic surgeons who specialise in treating and researching paediatric anterior cruciate ligament (ACL) injuries. Representatives from the American Orthopaedic Society for Sports Medicine, European Paediatric Orthopaedic Society, European Society for Sports Traumatology, Knee Surgery and Arthroscopy, International Society of Arthroscopy Knee Surgery and Orthopaedic Sports Medicine, Pediatric Orthopaedic Society of North America, and Sociedad Latinoamericana de Artroscopia, Rodilla y Deporte attended. Physiotherapists and orthopaedic surgeons with clinical and research experience in the field, and an ethics expert with substantial experience in the area of sports injuries also participated. Injury management is challenging in the current landscape of clinical uncertainty and limited scientific knowledge. Injury management decisions also occur against the backdrop of the complexity of shared decision-making with children and the potential long-term ramifications of the injury. This consensus statement addresses six fundamental clinical questions regarding the prevention, diagnosis, and management of paediatric ACL injuries. The aim of this consensus statement is to provide a comprehensive, evidence-informed summary to support the clinician, and help children with ACL injury and their parents/guardians make the best possible decisions.

Contralateral knee hyperextension is associated with increased anterior tibial translation and fewer meniscal injuries in the anterior cruciate ligament-injured knee

PURPOSE

To investigate the influence of hyperextension of the contralateral healthy knee on anterior tibial translation (ATT) and the presence of associated injuries in the anterior cruciate ligament (ACL)-injured knee.

METHODS

A local patient data register containing the surgical and clinical data of patients undergoing ACL reconstruction was analyzed. Patients were divided into groups according to the degree of hyperextension of the contralateral knee: normal (Group A ≤ 0°), mild (Group B 1°-5°), moderate (Group C 6°-10°), and severe (Group D > 10°). The ATT was measured in both knees preoperatively and 6 months postoperatively using the KT-1000 arthrometer. The presence of associated meniscal and cartilage injuries was noted. Using multivariate analysis, Groups B, C, and D were compared with Group A, using this group as a reference.

RESULTS

A total of 10,957 patients were available in the register and 8502 (Group A n = 4335, Group B n = 3331, Group C n = 771, Group D n = 65) were included in the final analysis. Groups B (10.3 mm; 95% CI 0.06-0.042, p < 0.0001) and C (10.6 mm; 95% CI 0.23-0.89, p = 0.006) showed significantly greater preoperative ATT in the injured knee compared with the control group (10.1 mm). Moreover, at the 6-month follow-up, greater ATT was observed for Groups B (8.5 mm; 95% CI 0.13-0.45, p < 0.0001), C (8.5 mm; 95% CI 0.02-0.60, p = 0.035), and D (9.1 mm; 95% CI - 0.08-1.77, p = 0.082) compared with Group A (8.2 mm). Meniscal injuries were less frequent in patients with contralateral hyperextension [Group B 903 (27.1%) p < 0.0001, Group C 208 (27.0%) p = 0.0003, and Group D 12 (18.5%), 0.012] compared with the control group [Group A 1479 (34.1%)].

CONCLUSION

Contralateral knee hyperextension is associated with greater pre- and postoperative ATT in the ACL-injured knee. In patients with contralateral knee hyperextension, concomitant injuries to the menisci are less frequent. Surgeons should consider grafts with superior properties regarding postoperative anteroposterior laxity to patients with contralateral knee hyperextension.

LEVEL OF EVIDENCE

Retrospective cohort study, Level IV.

Incidence and body location of reported acute sport injuries in seven sports using a national insurance database

Sports with high numbers of athletes and acute injuries are an important target for preventive actions at a national level. Both for the health of the athlete and to reduce costs associated with injury. The aim of this study was to identify injuries where injury prevention should focus, in order to have major impact on decreasing acute injury rates at a national level. All athletes in the seven investigated sport federations (automobile sports, basketball, floorball, football (soccer), handball, ice hockey, and motor sports) were insured by the same insurance company. Using this insurance database, the incidence and proportion of acute injuries, and injuries leading to permanent medical impairment (PMI), at each body location, was calculated. Comparisons were made between sports, sex, and age. In total, there were 84 754 registered injuries during the study period (year 2006-2013). Athletes in team sports, except in male ice hockey, had the highest risk to sustain an injury and PMI in the lower limb. Females had higher risk of injury and PMI in the lower limb compared to males, in all sports except in ice hockey. This study recommends that injury prevention at national level should particularly focus on lower limb injuries. In ice hockey and motor sports, head/neck and upper limb injuries also need attention.

A non-response analysis of 2-year data in the Swedish Knee Ligament Register

PURPOSE

To analyse the non-response group in the Swedish Knee Ligament Register (SKLR).

METHODS

All 3588 patients in the SKLR who had undergone anterior cruciate ligament surgery in 2010 were included. Respondents (n = 1865) and non-respondents (n = 1723) at the 2-year follow-up survey were assessed for potential differences in demographics and baseline data. KOOS/EQ5D questionnaires were sent to non-respondents together with a non-response survey asking questions about reasons for dropout.

RESULTS

Respondents had a significantly higher mean age (27.8 years, range 9-64) than non-respondents (25.9 years, range 12-65) (p < 0.001). Women had a higher rate of response 927 (62.8 %) than men 938 (44.4 %) even after correction for age (p < 0.001). Alpine/telemark skiing was the only activity at time of injury that showed higher rate of respondents 280 (62.5 %) compared to non-respondents 168 (37.5 %) (p < 0.001). No differences in EQ5D at 2-year follow-up were found between the groups. The change in KOOS from 0 to 2 years showed difference in the subscale pain with 9.4 in the response group compared to 6.3 in the late-response group (p < 0.05) and the subscale quality of life with a difference of 26.1 and 22.6, respectively (p < 0.05). The non-response questionnaire showed shortcomings in patient information regarding the importance of the SKLR.

CONCLUSION

The register is valid concerning baseline surgical data, but higher age, female gender and perhaps higher socioeconomic status improve the response rates. KOOS showed small differences of questionable clinical significance. The SKLR patient information could be improved.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Equivalent Knee Injury and Osteoarthritis Outcome Scores 12 and 24 Months After Anterior Cruciate Ligament Reconstruction: Results From the Swedish National Knee Ligament Register

BACKGROUND

It is not clear whether Knee injury and Osteoarthritis Outcome Score (KOOS) results will be different 1 or 2 years after anterior cruciate ligament (ACL) reconstruction.

PURPOSE

To investigate within individual patients enrolled in the Swedish National Knee Ligament Register whether there is equivalence between KOOS at 1 and 2 years after primary ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

This cohort study was based on data from the Swedish National Knee Ligament Register during the period January 1, 2005, through December 31, 2013. The longitudinal KOOS values for each individual at the 1- and 2-year follow-up evaluations were assessed through the two one-sided test (TOST) procedure with an acceptance criterion of 4. Subset analysis was performed with patients classified by sex, age, graft type, and type of injury (meniscal and/or cartilage injury).

RESULTS

A total of 23,952 patients were eligible for analysis after exclusion criteria were applied (10,116 women, 42.2%; 13,836 men, 57.8%). The largest age group was between 16 and 20 years of age (n = 6599; 27.6%). The most common ACL graft was hamstring tendon (n = 22,504; 94.0%), of which the combination of semitendinosus and gracilis was the most common. A total of 7119 patients reported on the KOOS Pain domain at both 1- and 2-year follow-ups, with a mean difference of 0.21 (13.1 SD, 0.16 SE [90% CI, -0.05 to 0.46], P < .001). The same results were found for the other KOOS subscales: symptoms (mean difference -0.54, 14.1 SD, 0.17 SE [90% CI, -0.81 to -0.26], P < .001), activities of daily living (mean difference 0.45, 10.8 SD, 0.13 SE [90% CI, 0.24 to 0.66], P < .001), sports and recreation (mean difference -0.35, 22.7 SD, 0.27 SE [90% CI, -0.79 to 0.09], P < .001), quality of life (mean difference -0.92, 20.0 SD, 0.24 SE [90% CI, -1.31 to -0.53], P < .001), and the combined KOOS-4 score (mean difference -0.41, 14.5 SD, 0.17 SE [90% CI, -0.70 to -0.13], P < .001). Analyses within specific subsets of patients showed equivalent results between the 2 follow-up evaluations.

CONCLUSION

Equivalent results within patients were found in KOOS values at 1- and 2-year follow-ups after ACL reconstruction. The finding was consistent across all KOOS subscales and for all evaluated subsets of patients. This result implies that there is no additional value in capturing both 1- and 2-year KOOS outcomes after ACL reconstruction. However, these findings of equivalence at 1- and 2-year endpoints do not alleviate the need for longer follow-up periods.

Epidemiology of surgically treated posterior cruciate ligament injuries in Scandinavia

PURPOSE

The main purpose of the study was to provide an overview of injury mechanisms, concomitant injuries, and other relevant epidemiological data for patients treated in Scandinavia with posterior cruciate ligament reconstruction (PCLR) following a posterior cruciate ligament (PCL) injury.

METHODS

A total number of 1287 patients who underwent PCLR from 2004 to 2013 in the Scandinavian counties were included from the national ligament registries. The variables such as age, sex, activity, and graft used for reconstruction were collected. Then, injuries were sorted based on concomitant injuries. Finally, data from the different registries were compared.

RESULTS

Average age of the treated patients was 32.7 years. Sex distribution ratio of male to female was 858:429 (66.7 %:33.3 %). Depending on definition, 26-37 % of the injuries treated were isolated PCL injuries. PCL injuries were most commonly encountered in sports with 35.4 % of the total number of PCL injuries in the study population. Soccer was the sport with the highest number of injuries (13.1 %). Cartilage lesions occurred in 26.1 % of PCL injuries and meniscal lesions in 21.0 %. Minimum one other additional ligament was injured in 62.2 %.

CONCLUSION

Isolated PCL injuries are common, although the injury is most commonly associated with other ligament injuries. There is a high prevalence of cartilage injuries and meniscal lesions associated with PCL injuries. Sports are the leading cause of PCL injuries treated operatively. Epidemiological data are a necessary part of the basis for injury prevention in the future. The prevalence of concomitant injuries is also relevant and clinically important for the choice of surgical procedure and for the expected outcomes following surgery.

LEVEL OF EVIDENCE

II.

Comparison of patient-reported outcomes among those who chose ACL reconstruction or non-surgical treatment

The aim of our study was to cross-sectionally compare patient-reported knee function outcomes between people who chose non-surgical treatment for ACL injury and those who chose ACL reconstruction. We extracted Knee Injury and Osteoarthritis Outcome Score (KOOS) and EuroQoL-5D data entered into the Swedish National ACL Registry by patients with a non-surgically treated ACL injury within 180 days of injury (n = 306), 1 (n = 350), 2 (n = 358), and 5 years (n = 114) after injury. These data were compared cross-sectionally to data collected pre-operatively (n = 306) and at 1 (n = 350), 2 (n = 358), and 5 years (n = 114) post-operatively from age- and gender-matched groups of patients with primary ACL reconstruction. At the 1 and 2 year comparisons, patients who chose surgical treatment reported superior quality of life and function in sports (1 year mean difference 12.4 and 13.2 points, respectively; 2 year mean difference 4.5 and 6.9 points, respectively) compared to those who chose non-surgical treatment. Patients who chose ACL reconstruction reported superior outcomes for knee symptoms and function, and in knee-specific and health-related quality of life, compared to patients who chose non-surgical treatment.

Evaluation of Achilles and patellar tendinopathy with greyscale ultrasound and colour Doppler: using a four-grade scale

PURPOSE

In tendon research, using ultrasound (US), studies often refer to tendon thickness, structural abnormalities and neovascularisation. The reliability concerning these measurements and evaluations is seldom reported. The aim of this study was to assess the intra- and inter-observer reliability for quantitative measures (thickness) and qualitative evaluations (structure and neovascularisation) of symptomatic and asymptomatic Achilles and patellar tendons with US and colour Doppler using a modified Öhberg score.

METHODS

Twenty-eight consecutive patients with symptomatic and asymptomatic Achilles (n = 27) and patellar tendons (n = 26) were included. Tendon anteroposterior thickness was measured. Tendon structure and neovascularisation were evaluated using a modified Öhberg score. US-images were evaluated twice by four independent observers.

RESULTS

Mean thickness for Achilles and patellar tendons was 8.4 mm (±2.0) and 5.5 mm (±1.7), respectively. The reliability for measures of distance was high all over (ICC = 0.963-0.999). A moderate-strong correlation was found between observers concerning evaluation of neovascularisation (r = 0.767-0.992) and poor-moderate correlation concerning evaluation of structural changes (r = 0.379-0.837). Intra-observer reliability was moderate strong for evaluations of both tendon structure (k = 0.537-0.873) and neovascularisation (k = 0.639-0.864).

CONCLUSIONS

With a strict method for how to measure tendon thickness and set criteria for evaluating structural changes and amount and distribution of neovascularisation, US and colour Doppler is a reliable method for evaluating Achilles and patellar tendons. The modified, 4-graded, Öhberg score was found to be a reproducible instrument for assessment of tendon structure and neovascularisation.

Injuries in Swedish floorball: a cost analysis

The epidemiology of sport injuries is well documented. However, the costs are rarely discussed. Previous studies have presented such costs in specific sports or localization. No study has investigated the costs related to injuries in elite floorball. Thus, the aim of this study was to estimate cost of injuries in Swedish elite floorball players. During 1 year, 346 floorball players were prospectively followed. All time-loss injures were recorded. The injured players were asked to complete a questionnaire regarding their costs tied to the injury. Mean costs were calculated by multiplying the total resource use with the collected unit costs and dividing these total costs with the number of injuries as well as players. The results showed that the average cost per injury increased with the level of severity and ranged from 332 to 2358 Euros. The mild and moderate overuse injuries were costlier than the corresponding traumatic injuries. However, the severe traumatic injuries were associated with higher costs than overuse injuries. Knee injuries were the costliest. Our results indicate that there are costs to be saved, if floorball injuries can be avoided. They should be of interest to decision makers deciding whether to invest in preventive interventions.

Effect on Patient-Reported Outcomes of Debridement or Microfracture of Concomitant Full-Thickness Cartilage Lesions in Anterior Cruciate Ligament-Reconstructed Knees: A Nationwide Cohort Study From Norway and Sweden of 357 Patients With 2-Year Follow-up

BACKGROUND

The treatment of concomitant cartilage lesions in anterior cruciate ligament (ACL)-injured knees is debatable.

PURPOSE

To evaluate the effect of debridement or microfracture (MF) compared with no treatment of concomitant full-thickness (International Cartilage Repair Society [ICRS] grades 3-4) cartilage lesions on patient-reported outcomes after ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Six hundred forty-four patients who underwent primary unilateral ACL reconstruction and had a concomitant full-thickness cartilage lesion treated simultaneously by debridement (n = 129) or MF (n = 164), or underwent no treatment (n = 351) of the cartilage lesion, registered in the Norwegian and Swedish National Knee Ligament Registries from 2005 to 2008 were included. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to measure patient-reported outcomes. At a mean follow-up of 2.1 ± 0.2 years after surgery, 357 (55%) patients completed the KOOS. Linear regression analyses were used to evaluate the effect of debridement or MF on the KOOS.

RESULTS

No significant effects of debridement were detected in the unadjusted or adjusted regression analyses on any of the KOOS subscales at 2-year follow-up. The MF treatment of the cartilage lesions had significant negative effects at 2-year follow-up on the KOOS Sport and Recreation (Sport/Rec) (regression coefficient [β] = -8.9; 95% confidence interval [CI], -15.1 to -1.5) and Knee-Related Quality of Life (QoL) (β = -8.1; 95% CI, -14.1 to -2.1) subscales in the unadjusted analyses. When adjusting for confounders, MF had significant negative effects on the same KOOS subscales of Sport/Rec (β = -8.6; 95% CI, -16.4 to -0.7) and QoL (β = -7.2; 95% CI, -13.6 to -0.8). For the remaining KOOS subscales of Pain, Symptoms, and Activities of Daily Living, there were no significant unadjusted or adjusted effects of MF.

CONCLUSION

MF of concomitant full-thickness cartilage lesions showed adverse effects on patient-reported outcomes at 2-year follow-up after ACL reconstruction. Debridement of concomitant full-thickness cartilage lesions showed neither positive nor negative effects on patient-reported outcomes at 2-year follow-up after ACL reconstruction.

Sclerosing injections and ultrasound-guided arthroscopic shaving for patellar tendinopathy: good clinical results and decreased tendon thickness after surgery-a medium-term follow-up study

PURPOSE

Treatment of patellar tendinopathy/jumper's knee with ultrasound-guided sclerosing injections or ultrasound-guided arthroscopic shaving has shown good clinical short-term results. Former studies indicate that the tendon thickness and structure stays unaffected after successful treatment. The aim of this study was to evaluate the sonographic findings and clinical outcome 3-5 years after treatment of patellar tendinopathy with ultrasound-guided sclerosing injections or arthroscopic shaving.

METHODS

Fifty-seven patellar tendons (43 patients) with chronic patellar tendinopathy were evaluated, with ultrasound, colour Doppler (CD) and visual analogue scale (VAS) for pain and satisfaction with treatment, 3-5 years after treatment. Functional status was evaluated with a single question-"Back in full loading activity?" yes or no.

RESULTS

At endpoint (mean 46 months), there was a significant decrease in anteroposterior thickness of the proximal patellar tendon in patients treated with ultrasound-guided arthroscopic shaving but not after sclerosing injections. Tendon structure had improved, and CD local blood flow had diminished significantly in both groups. There were good clinical results with a significant decrease in VAS for pain after sclerosing injections (VAS 64 ± 18 → 17 ± 23) with 74 % satisfied patients and also after arthroscopic shaving (VAS 77 ± 16 → 13 ± 23) with 80 % satisfied patients. There were no significant differences in VAS between groups. A significant correlation between low local blood flow and high patient satisfaction was found.

CONCLUSIONS

Tendon thickness decreased over time after ultrasound-guided arthroscopic shaving, and tendon structure and local blood flow decreased after both treatments. There were good, and similar, clinical results with both methods.

LEVEL OF EVIDENCE

III.

Incidence and severity of reported acute sports injuries in 35 sports using insurance registry data

Acute injuries in sport are still a problem where limited knowledge of incidence and severity in different sports at national level exists. In Sweden, 80% of the sports federations have their mandatory injury insurance for all athletes in the same insurance company and injury data are systematically kept in a national database. The aim of the study was to identify high-risk sports with respect to incidence of acute and severe injuries in 35 sports reported to the database. The number and incidences of injuries as well as injuries leading to permanent medical impairment (PMI) were calculated during 2008-2011. Each year approximately 12,000 injuries and 1,162,660 licensed athletes were eligible for analysis. Eighty-five percent of the injuries were reported in football, ice hockey, floorball, and handball. The highest injury incidence as well as PMI was in motorcycle, handball, skating, and ice hockey. Females had higher risk of a PMI compared with males in automobile sport, handball, floorball, and football. High-risk sports with numerous injuries and high incidence of PMI injuries were motorcycle, handball, ice hockey, football, floorball, and automobile sports. Thus, these sports ought to be the target of preventive actions at national level.

No difference in revision rates between single- and double-bundle anterior cruciate ligament reconstruction: a comparative study of 16,791 patients from the Swedish national knee ligament register

PURPOSE

The purpose was to compare revision rates and patient-reported outcomes between single- and double-bundle anterior cruciate ligament (ACL) reconstructions.

METHODS

All patients from the Swedish National Knee Ligament Register from 2005 through 2011 who underwent primary ACL reconstruction with hamstring autografts were included. Patients with concomitant injuries, except meniscal and chondral injuries, were excluded. By December 31, 2011, 16,791 primary isolated ACL reconstructions had been registered, of which 16,281 were single-bundle and 510 were double-bundle. Cumulative revision rates were estimated using Kaplan-Meier analysis. The Knee injury and Osteoarthritis Outcome Score (KOOS) and EQ-5D were calculated at 1- and 2-year follow-ups.

RESULTS

The revision rate showed no statistically significant differences between the groups (P = .30). Over the 7-year observation period, 347 single-bundle (2.1%) and 8 double-bundle (1.6%) ACL reconstructions were revised. No significant differences in the KOOS or EQ-5D were found between the groups postoperatively. In addition, there were no differences in postoperative improvements in the KOOS or EQ-5D at 1- and 2-year follow-ups.

CONCLUSIONS

Revision rates after single- and double-bundle ACL reconstructions were low. No differences were found in revision rates, KOOS, and EQ-5D between the 2 techniques.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.