Female Soccer Players With Anterior Cruciate Ligament Reconstruction Have a Higher Risk of New Knee Injuries and Quit Soccer to a Higher Degree Than Knee-Healthy Controls

More knee reinjuries after ACL reconstruction compared to nonsurgical treatment of the ACL. A 2-year follow-up of the NACOX prospective cohort study

PURPOSE

To describe knee reinjuries and surgeries within 2 years after an acute anterior cruciate ligament (ACL) injury, in patients treated with or without ACL reconstruction (ACLR).

METHODS

Two years follow-up of 275 patients (52% females, mean age 25.2 [SD 7.0] years) about knee reinjuries and surgeries were analysed from the prospective NACOX cohort study, aiming to describe recovery after an acute ACL injury treated according to clinical routine. Knee reinjury was defined as increase or new symptoms due to new trauma. At 2 years after injury, 169 (61%) had undergone an ACLR. Results are presented with descriptive statistics and risk ratios (RR).

RESULTS

Thirty-two patients sustained reinjuries within 2 years; 6 in the non-ACLR group, and 26 in the ACLR group (7 before and 19 after ACLR). Twelve patients in the ACLR group sustained a graft rupture and three did an ACL revision. Patients with non-ACLR, aged 21-25 years, had a 5.9-fold higher risk for reinjury than those aged 15-20 years (RR 5.9 [1.3-26.9]; p = 0.012). Twenty-four patients had surgery in the non-ACLR group and 36 patients in the ACLR group (excluding primary ACLR), where six were before ACLR and 30 were after ACLR.

CONCLUSION

Twelve percent sustained a knee reinjury and 21% underwent knee surgery within 2 years after the index ACL injury. There was a higher reinjury incidence in the ACLR group, but no difference in incidence of surgeries. Thus, ACLR did not reduce the risk of traumatic reinjuries or surgeries, which is important for treatment decision considerations.

LEVEL OF EVIDENCE

Level I.

High risk of new knee injuries, lower activity level and reduced knee function: A controlled follow-up of male football (soccer) players 6-9 years after primary anterior cruciate ligament reconstruction

OBJECTIVES

To study the risk of new knee injuries and patient-reported outcomes in male football players at any playing level 6-9 years after primary anterior cruciate ligament reconstruction (ACLR) versus knee-healthy controls.

DESIGN

Cohort study.

METHODS

Football players (n = 384) who underwent an ACLR between 1 and 3 years previously and knee-healthy controls (n = 110) were surveyed regarding football playing status, activity level (Tegner Activity Scale), knee function (0-10 scale), satisfaction with current activity level (1-10), satisfaction with knee function (1-7), and new knee injuries.

RESULTS

Ninety-three players with ACLR and 63 knee-healthy controls were included and followed for mean 5.4 years (6-9 years after primary ACLR for players with ACLR). Thirty-four players with ACLR (37 %) had sustained a new ACL injury (re-rupture or contralateral rupture) versus 5 (8 %) controls. Players with ACLR had almost 5-fold higher risk of new ACL injury than controls (risk ratio, 4.61; 95 % confidence interval, 1.91-11.13; p < 0.001). Compared with controls, players with ACLR played football to a lower extent (27 % vs 65 %, p < 0.001) had a lower activity level (Tegner: median [interquartile range], 4 [6] vs 9 [5], p < 0.001), knee function (median, 8 [3] vs 9 [2], p < 0.001), and satisfaction with activity level (median, 7 [3] vs 8 [3], p = 0.014) and knee function (median, 2 [2] vs 1 [1], p < 0.001).

CONCLUSIONS

One-third of male football players with ACLR sustained a new ACL injury within 6-9 years, with an almost 5-fold higher risk than controls. Players with ACLR had lower activity level and knee function and were less satisfied with knee function and activity level.

Lateral Extra-Articular Tenodesis With Iliotibial Band in Anterior Cruciate Ligament Autograft Reconstruction for Female Soccer Athletes With Generalized Ligamentous Laxity Yields Graft Failure and Return-to-Sport Rates Comparable With Athletes Without Generalized Laxity

PURPOSE

To evaluate the effectiveness of adding lateral extra-articular tenodesis (LET) to primary anterior cruciate ligament reconstruction (ACLR) in competitive female soccer athletes with greater preoperative generalized ligamentous laxity.

METHODS

A retrospective review of female high school and collegiate soccer players who underwent primary ACLR from 2013 to 2021, with a minimum of 2 years of follow-up, was conducted. Participants were divided into 2 groups: those who received ACLR alone and those who received ACLR with LET. Generalized ligamentous laxity was defined as a Beighton score ≥4 and was not considered an indication for LET. Anterior cruciate ligament (ACL) autografts included the quadriceps, bone-patellar tendon-bone, and hamstrings in both groups. Patient demographics and physical examination findings, including pivot shift results, were collected. Positive pivot-shift refers to a grade ≥2. Patient outcomes included graft failure (defined as ACL retear), International Knee Documentation Committee score, Lysholm score, return to sport, and complications. Independent t tests, χ2 tests, and Mann-Whitney U tests were conducted to compare outcomes between the 2 groups. Minimally clinical important difference was calculated from preoperative to final follow-up.

RESULTS

A total of 133 female soccer players who underwent ACLR met inclusion criteria, including 43 patients that received an ACLR + LET and 90 patients who underwent isolated ACLR. Average follow-up was 39.0 and 36.1 months in the LET group and the control group, respectively. Patients who underwent LET had a greater generalized ligamentous laxity rate (48.8% vs 18.9%; P < .001) and greater median Beighton score (3.0 vs 1.0; P < .001) than those without LET. There was a similar rate of graft failure in patients who underwent LET compared with the control group (4.7% vs 3.0%; P = .658). On the basis of minimally clinical important difference thresholds, there were no clinically relevant differences in International Knee Documentation Committee or Lysholm scores noted between the 2 groups. Return-to-sport rates also were comparable between the LET and control cohorts (90.7% vs 85.6%; P = .807).

CONCLUSIONS

The addition of LET during ACLR in female soccer players with preoperative generalized ligamentous laxity yields graft retear and return-to-sport rates comparable with those of athletes without ligamentous laxity.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Combining a digital health application with standard care significantly enhances rehabilitation outcomes for ACL surgery patients

INTRODUCTION

Anterior cruciate ligament (ACL) rupture is one of the most common sports injuries. Regardless of the surgical treatment, patients require intensive education about the pathology, therapeutic options and physical therapy. However, it is often not possible for the patient to start physical therapy directly and schedule adequate consultations. Digital health applications are medical devices that can help bridge the gap between physiotherapy sessions and provide qualified, convenient and effective education and treatment. This study is needed to explore alternative methods to ensure continuous and effective rehabilitation for ACL patients who face delays in accessing traditional physiotherapy. The study aimed to compare app-assisted therapy plus standard of care (conventional orthopaedic and physiotherapeutic measures) versus isolated standard of care for patients with planned ACL surgery.

METHODS

A monocentric, two-arm, 1:1 randomized controlled study examined 80 patients after a cruciate ligament rupture with or without meniscal injury. Patients over 18 years with a confirmed diagnosis of ACL rupture and planned surgical reconstruction using autologous grafts were included. The study criteria additionally included willingness to use the Orthopy app and sufficient German language proficiency. The study excluded patients with severe concomitant injuries, prior knee surgeries, chronic pain conditions and those not compatible with app usage. Patients were randomized and their baseline data (t0) was collected. Subsequently, they received their treatment according to their treatment group. The study included a presurgery period (2-6 weeks) and a postsurgery period (14 weeks). Interim assessments were done via online questionnaires at t1 (if more than 3 weeks before surgery) and t3, t4 and t5 (postsurgery). Additional clinical assessments were conducted at t2 (presurgery) and t6 (14 weeks postsurgery). Primary outcome measures included the knee injury and osteoarthritis outcome score (KOOS), with subjective pain and function levels (numeric rating scale [NRS]) as secondary endpoints.

RESULTS

The clinical trial was able to show positive outcomes on the KOOS Pain and Symptoms subscale of the primary endpoint KOOS in the interventional group compared to the standard of care group. A statistically significant pain reduction could be seen at t1 (p = 0.0005), t2 (p = 0.0068) and t4 (approximately 6 weeks after surgery; p = 0.01). A significant reduction of symptoms at t1 (p = 0.0001), t2 (p = 0.0036) and t6 (p = 0.0377) were recognized. These findings are further supported by the significant benefit of the pain NRS at t4 and positive tendencies at t3, t5 and t6. The KOOS subscales quality of life (p = 0.0066), activities of daily living (p = 0.0009) and Sport (p = 0.0484) showed significant effects before surgery.

CONCLUSION

The Orthopy app is a medical device that is both safe and effective for use. Combining the Orthopy app and standard of care can significantly improve prehabilitation and rehabilitation in surgical treatment with ACL reconstruction compared with the isolated standard of care.

LEVEL OF EVIDENCE

Level I.

Return to competition after ACL reconstruction: Factors influencing rates and timing in Swedish football players

PURPOSE

To investigate the rate and timing for return to football league games after anterior cruciate ligament reconstruction (ACLR) in Swedish players, examining associations with sex, age, level, graft and additional ACL surgery.

METHOD

Data from the Swedish National Knee Registry (SNKLR) and the Swedish Football Association's IT System (FOGIS) were used. The study cohort comprised 971 football players, 64% males, who underwent primary ACLR. Demographics, graft type and surgical information were extracted from the SNKLR and game participation from FOGIS. Follow-up for return to competition (RTC) was conducted for 36 months, while additional ACLR follow-up was 3-7 years. Statistical analyses, including Kaplan-Meier survival curves and relative risk calculations, were employed to assess factors influencing RTC rates and timing.

RESULTS

Out of 971 players analyzed, 53% RTC within 3 years with no difference between males and females, at a mean of 15 months (median 14 months) from surgery to the first game. Eleven (2%) players RTC < 6 months from ACLR, 62 (12%) 6-9 months, 125 (24%) 9-12 months and 331 (63%) >12 months. Patellar tendon (PT) grafts demonstrated superior performance, showing quicker returns and higher RTC rates (p = 0.005) compared to hamstring (hazard ratio [HR]: 0.63 [0.48-0.84]) and quadriceps tendon grafts (HR: 0.53 [0.30-0.93]). Players competing in higher divisions pre-injury experienced significantly swifter and higher RTC rates (p < 0.001). Ninety-five (10%) had a registered additional ACLR. Players who RTC did not exhibit a significantly higher rate of revision (35 [7%] vs. 25 [5%]). However, those who returned faced a heightened risk of contralateral ACLRs compared to those who did not RTC (32 [6%] vs. 4 [1%] RR 1.72 [1.59-1.96], p < 0.001).

CONCLUSION

The study reveals that 53% of football players RTC after ACLR, predominantly after more than 12 months. The RTC was higher and faster in high-level players and those receiving a PT graft. The slow RTC may contribute to the relatively low rate of additional ACLRs.

LEVEL OF EVIDENCE

Level III.

Limited Use of Supervised Physical Rehabilitation Beyond 3 Months After Arthroscopic Anterior Cruciate Ligament Reconstruction With Greater Use in Female and Younger Patients

PURPOSE

To characterize the initiation and use of supervised physical rehabilitation after arthroscopic anterior cruciate ligament reconstruction (ACLR), including overall duration of rehabilitation and number of rehabilitation visits, and to describe demographic and clinical predictors of rehabilitation initiation and use characteristics.

METHODS

Patients aged 14 to 64 years in the United States who underwent ACLR from 2017 to 2020 were identified using the Merative MarketScan Database. For patients initiating rehabilitation within 45 days postoperatively, the overall duration and number of visits within 1 year after surgery were determined. Visits were categorized into rehabilitation phases, with visits 0-90 days postoperatively categorized as phase I, 91-180 days as phase II, 181-270 days as phase III, and 271-365 days as phase IV. Multivariable regression models identified predictors of rehabilitation initiation, duration in days, and number of visits.

RESULTS

Of 20,097 patients who underwent ACLR, 88.1% (n = 17,704) initiated postoperative rehabilitation, receiving phase I services. Additionally, 55.0% (n = 11,053) received phase II services, 17.0% (n = 3417) phase III services, and 3.9% (n = 779) phase IV services. The median duration was 104 days (interquartile range 63-157), and the median number of visits was 21 (interquartile range 12-32). Multiple significant predictors of rehabilitation initiation, duration, and number of visits were found.

CONCLUSIONS

Although most patients use supervised physical rehabilitation after ACLR, only 55% receive rehabilitation beyond 3 months and only 17% beyond 6 months after surgery. There are several significant drivers of rehabilitation initiation, overall duration, and number of visits. Female and younger patients have greater use of rehabilitation, and notable regional differences suggest an opportunity to improve standardization of care.

LEVEL OF EVIDENCE

Level III, retrospective descriptive study.

Revision ACL reconstruction, but not bilateral ACL reconstruction, is associated with clinically relevant inferior subjective knee function compared with primary ACL reconstruction: A comparative analysis of 6831 patients

PURPOSE

To evaluate and compare the subjective knee function in patients undergoing revision and bilateral anterior cruciate ligament (ACL) reconstruction (ACLR) with those undergoing primary ACLR in a large cohort.

METHODS

Patients without concomitant ligament injuries who underwent primary, revision or bilateral ACLR at the Capio Artro Clinic, Stockholm, Sweden, between 2005 and 2018 were identified. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at 1, 2 and 5 years postoperatively from the Swedish National Knee Ligament Registry. Patients who underwent revision and bilateral ACLR were compared with those who underwent primary ACLR (control group) using Student's t test.

RESULTS

A total of 6831 patients (6102 with primary ACLRs, 343 with revision ACLRs and 386 with bilateral ACLRs) were included. Preoperatively, there were significant but nonclinically relevant differences in favour of the revision ACLR group for KOOS Symptoms, Pain, Activities of Daily Living (ADL) and Sport/Rec subscale scores compared with the primary ACLR group. Postoperatively, except for the 1-year Symptoms and ADL subscales, the revision ACLR group reported significantly lower scores on all KOOS subscales than the primary ACLR group, with clinically relevant differences (>8-10 points) for the 1-, 2- and 5-year Sport/Rec and Quality of Life (QOL) subscales. The bilateral ACLR group reported significantly, but not clinically relevant, inferior scores on the 1-year Symptoms and QOL subscales and the 5-year Sport/Rec and QOL subscales compared with the primary ACLR group.

CONCLUSIONS

Revision ACLR, but not bilateral ACLR, was associated with clinically relevant inferior subjective knee function compared with primary ACLR. It is important to counsel patients regarding their future subjective knee function after repeated ACLR. Compared to primary ACLR, inferior subjective results should be expected after revision ACLR, but not after bilateral ACLR.

LEVEL OF EVIDENCE

Level III.

The Effect of Primary ACL Reconstruction on Career Longevity in English Premier League and Championship Soccer Players Compared With Uninjured Controls: A Matched Cohort Analysis

BACKGROUND

Because of the multitude of variables that affect the retirement decisions of professional soccer players, it has proven difficult to isolate the effect of undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) on career longevity.

PURPOSE

To compare the career longevity of professional soccer players after a primary ACLR with that of an uninjured matched control cohort.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review of a consecutive series of primary ACLR was performed between 2008 and 2018 in professional male soccer players from the senior author's practice. Each athlete with ACLR was matched to 3 control athletes who had not undergone ACLR according to age, league, playing position, and preinjury game appearances/minutes played. Player career statistics-including league, game appearances, and game minutes-were compiled for each year until retirement or July 1, 2022.

RESULTS

A total of 82 soccer players in the English Premier League or Championship at the time of their primary ACLR were matched to 246 control athletes. The mean career length after ACLR was 6 ± 2.6 years, while that of the matched control athletes was 7.6 ± 2.8 years (P < .001). After primary ACLR, an athlete had a 2 times greater chance of retirement compared with the matched control athlete (hazard ratio, 2.19; P < .001). At 5 years after ACLR, 16% of athletes had retired from professional soccer, while 8.5% of the matched cohort were retired (P = .060). By 10 years, 72% of the ACLR cohort had retired compared with 43% of the matched cohort (P < .001). Forwards were more likely to have shortened careers compared with goalkeepers (P = .021); however, no significant differences were observed between midfielders, defenders, and forwards. Within the ACLR cohort, a contralateral ACL tear during the athlete's career caused a 2.30 times (P = .022) increased chance of retirement compared with athletes with only 1 ACL tear during their career. Mechanism of injury, meniscal pathology, graft rerupture, and chondral lesions did not affect career length.

CONCLUSION

Professional male soccer players who underwent ACLR had decreased career length by approximately 1.6 years compared with a matched player cohort.

Outcomes of bone-patellar tendon-bone autograft and quadriceps tendon autograft for ACL reconstruction in an all-female soccer player cohort with mean 4.8-year follow up

OBJECTIVE

The purpose is to compare functional outcomes, return to soccer rates, and revision rates in an all-female soccer player cohort undergoing quadriceps tendon (QT) autograft ACLR versus bone-patellar tendon-bone (BPTB) autograft ACLR.

METHODS

Female soccer players who sustained an ACL rupture and underwent primary anatomic, single-bundle ACLR with BPTB autograft or QT autograft were included. Demographic and surgical characteristics were collected. Outcomes of interest included Tegner score, International Knee Documentation Committee (IKDC) score, Marx score, return to soccer rates, and failure rates.

RESULTS

Data on 23 patients undergoing BPTB autograft ACLR and 14 undergoing QT autograft ACLR was available. Average age was 18.7 years, and average follow up was 4.8 years. Overall, 76 ​% (28/37) returned to soccer and 5.4 ​% (2/37) underwent revision ACLR. No major significant differences were found in demographic or surgical characteristics. No differences were found in postoperative IKDC scores, preoperative, postoperative, or change from pre-to postoperative Marx activity scores, or pre-and postoperative Tegner scores between the groups. QT autograft ACLR patients had significantly less change in Tegner scores pre-to postoperatively compared to the BTPB autograft ACLR group (0.6 ​± ​1.2 versus 2.1 ​± ​1.8; p ​= ​0.02). Both groups had similar rates of return to soccer [78 ​% (18/23) BPTB autograft ACLR versus 71 ​% (10/14) QT autograft ACLR; p ​= ​0.64] and rates of revision (8.7 % (2/23) BPTB autograft ACLR; 0 % (0/14) QT autograft ACLR.

CONCLUSION

Results of this study suggest that BPTB autograft ACLR and QT autograft ACLR produce comparable, successful functional and return to soccer outcomes in this all-female soccer player cohort study. Larger, prospective studies are needed to improve the strength of conclusions and provide more information on the optimal graft choice for female soccer players. Surgeons can use the results of this study to counsel female soccer players on expected outcomes after ACLR.

LEVEL OF EVIDENCE

III.

Epidemiology of Anterior Cruciate Ligament Tears in National Collegiate Athletic Association Athletes: 2014/2015-2018/2019

PURPOSE

This study aimed to describe the epidemiology of ACL tears in NCAA men's and women's sports.

METHODS

Injury and exposure data collected within the NCAA Injury Surveillance Program from 2014/2015 to 2018/2019 were analyzed. ACL tear frequencies, injury rates (IR), and injury proportions were used to describe injury incidence by sport, event type, injury mechanism, and injury history. Injury rate ratios (IRR) were used to examine differential injury rates, and injury proportion ratios (IPR) were used to examine differential distributions.

RESULTS

A total of 729 ACL tears were reported from 8,474,401 recorded athlete exposures (AE) during the study period (IR = 0.86 per 10,000 AE), and the competition-related ACL tear rate was higher than the practice-related rate (IRR = 5.52, 95% confidence interval [CI] = 4.75-6.39). Among men's sports, the highest overall ACL tear rate was observed in men's football (IR = 1.44 per 10,000 AE), whereas among women's sports, the highest overall rate was observed in women's soccer (IR = 2.60 per 10,000 AE). Among sex-comparable sports, ACL tear rates were higher in women's basketball, softball, and soccer, as compared with their men's counterparts. ACL tears were more prevalently attributed to player contact mechanisms in men's sports than women's sports (IPR = 1.73, 95% CI = 1.37-2.19), but more prevalently attributed to noncontact mechanisms in women's sports than men's sports (IPR = 1.17, 95% CI = 1.01-1.35).

CONCLUSIONS

ACL tear risk in women's sports continues to warrant attention and prevention efforts. Given the differential rates by event type, future research efforts may also evaluate initiatives to reduce competition-related injury burden in NCAA sports.

Are We Jumping to the Wrong Conclusions? Longer Jumps and More Hops in Female Football Players Who Went on to Sustain a Primary or Secondary ACL Injury Compared to Those Who Did Not

BACKGROUND

Different functional performance tests are used to assess patients in the clinic and before return to sport (RTS), where the rehabilitation goal is to reach good strength and jumping ability. A limb symmetry index of ≥ 90% is a common target in rehabilitation before RTS. The aim of this short communication is to use data from our 2-year prospective cohort study on female football players, either with or without an anterior cruciate ligament (ACL) reconstruction, to discuss whether hop performance in 3 commonly used hop tests can inform safe football participation, that is, with a low risk for ACL injury or reinjury.

METHOD

At baseline, 117 active female football players (mean age ± standard deviation, 20 ± 2 years) were included 19 ± 9 months after ACL reconstruction as well as 119 matched female knee-healthy players (age 19 ± 3 years). All players performed a single hop for distance test, 5-jump test and side hop test at baseline and were then prospectively followed for 2 years. Twenty-eight (24%) players sustained a second ACL injury and 8 (7%) sustained a primary ACL injury.

RESULTS

Longer jumps in the 5-jump test (922 cm vs. 865 cm, Cohen's d =  - 0.60) and more hops in the side hop test for both limbs (41-42 hops vs. 33-36 hops, d =  - 0.43 to - 0.60) were seen in players who sustained a second ACL injury compared with those who did not. Longer jumps in the single hop for distance test (both limbs) (139-140 cm vs. 124-125 cm, d =  - 0.38 to - 0.44), in the 5-jump test (975 cm vs. 903 cm, d = -0.42) and more hops in the side hop test (both limbs) (48-49 hops vs. 37-38 hops, d =  - 0.38 to - 0.47) were seen in players who sustained a primary ACL injury compared with those who did not.

CONCLUSIONS

The average hop performance, i.e. longer jumps or more hops, was greater in players who went on to sustain a primary or secondary ACL injury compared to those who did not over a two-year follow-up period. Even though hop tests are not used in isolation to evaluate readiness to RTS, their interpretation needs consideration in the decision-making process of returning to pivoting sports.

Clinical Outcomes After ACL Reconstruction in Soccer (Football, Futbol) Players: A Systematic Review and Meta-Analysis

CONTEXT

The risk factors for anterior cruciate ligament (ACL) tear for athletes participating in pivoting sports includes young age and female sex. A previous meta-analysis has reported a reinjury rate of 15% after ACL reconstruction (ACLR) for athletes across all sports. To the best of the authors' knowledge, this is the first systematic review and meta-analysis of available literature reporting outcomes after ACLR in soccer players.

OBJECTIVE

To review and aggregate soccer-specific outcomes data after ACLR found in current literature to help guide a more tailored discussion regarding expectations and prognosis for soccer players seeking operative management of ACL injuries.

DATA SOURCES

A comprehensive search of publications was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SPORTDiscus databases.

STUDY SELECTION

Inclusion criteria consisted of original studies, level of evidence 1 to 4, studies reporting clinical and patient-reported outcomes (PROs) after primary ACLR in soccer players at all follow-up length.

STUDY DESIGN

The primary outcomes of interest were graft failure/reoperation rates, ACL injury in contralateral knee, return to soccer time, and PROs.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Search of literature yielded 32 studies for inclusion that involved 3112 soccer players after ACLR.

RESULTS

The overall graft failure/reoperation rate ranged between 3.0% and 24.8% (mean follow-up range, 2.3-10 years) and the combined ACL graft failure and contralateral ACL injury rate after initial ACLR was 1.0% to 16.7% (mean follow-up range, 3-10 years); a subgroup analysis for female and male players revealed a secondary ACL injury incidence rate of 27%, 95% CI (22%, 32%) and 10%, 95% CI (6%, 15%), respectively. Soccer players were able to return to play between 6.1 and 11.1 months and the majority of PROs showed favorable scores at medium-term follow-up.

CONCLUSION

Soccer players experience high ACL injury rates after primary ACLR and demonstrated similar reinjury rates as found in previous literature of athletes who participate in high-demand pivoting sports.

Self-reported knee function and activity level are reduced after primary or additional anterior cruciate ligament injury in female football players: a five-year follow-up study

BACKGROUND

Playing football involves a high risk of anterior cruciate ligament (ACL) injuries and these may affect knee function and activity level.

OBJECTIVES

To measure changes in self-reported knee function, activity level, and satisfaction with knee function and activity level in female football players with or without an ACL-reconstructed knee.

METHODS

Female football players, age 19.9 (SD 2.6) years, with either a primary ACL-reconstruction 1.6 (SD 0.7) years after ACL-reconstruction (n = 186) or no ACL injury (n = 113) were followed prospectively for five years. Self-reported data collected at baseline and follow-up included knee function (International Knee Documentation Committee Subjective Knee Form [IKDC-SKF]), activity level (Tegner Activity Scale), and satisfaction with knee function (Likert scale 1=happy; 7=unhappy) and activity level (1-10 scale). Information on any new ACL injury during the follow-up period was collected.

RESULTS

Players with ACL-reconstruction at baseline who either did (n = 56) or did not (n = 130) sustain an additional ACL injury, and players with no injury at baseline who remained injury free (n = 101) had a lower Tegner score at follow-up. Players with additional ACL injury had lower IKDC-SKF score (mean difference: -11.4, 95% CI: -16.0, -6.7), and satisfaction with activity level (mean difference: -1.5, 95% CI: -2.3, -0.7) at follow-up. Players with no additional ACL injury had higher satisfaction with knee function (mean difference: 0.6, 95% CI: 0.3, 0.9) at follow-up. Players with no ACL injury had lower satisfaction with activity level (mean difference: -0.7, 95% CI: -1.1, -0.3) at follow-up. Players with additional ACL injury had larger decreases in all variables measured compared to the two other groups.

CONCLUSION

Primary, and even more so additional, ACL injuries decreased self-reported knee function, activity level, and satisfaction with knee function and activity level in female football players.

Poorer patient-reported knee function and quality of life, but not activity level, after revision ACL reconstruction compared with primary ACL reconstruction: a matched-pair analysis with a minimum 5-year follow-up

BACKGROUND

An appropriate method for comparing knee function and activity level between patients with primary and revision anterior cruciate ligament reconstruction (ACLR) is to perform a matched-group analysis. The aim was to assess and compare knee function, knee-related quality of life and activity level between patients with revision ACLR and primary ACLR at a minimum of 5 years of follow-up.

METHODS

Patients aged ≤ 40 years old who underwent revision ACLR between 2010 and 2015 and a matched control group (primary ACLR) (1:1) with age ± 2 years, year of ACLR, sex, and pre-injury sport and Tegner Activity Scale (TAS) were retrospectively identified in our clinic database. The preoperative Knee injury and Osteoarthritis Outcome Score (KOOS) and surgical data were extracted and analyzed. Patients were mailed KOOS and EQ-5D questionnaires at a minimum of 5-years after revision ACLR. Study-specific questions about knee function, limitation in sport, satisfaction, and activity level according to the TAS (all scales of 1-10, 10 best) were also asked by telephone.

RESULTS

Seventy-eight patients with a revision ACLR (mean age ± SD, 29.9 ± 6.0 years) matched with seventy-eight patients with a primary ACLR (30.2 ± 5.8 years) were included. The follow-up for the revision ACLR group was 7.0 ± 1.5 years and for the primary ACLR group 7.7 ± 1.6 years. The revision ACLR group reported poorer KOOS scores in all subscales (p < 0.05) except the Symptoms subscale, poorer EQ-5D VAS (mean 79.2 ± 20.1 vs 86.0 ± 20.1, p = 0.012), and less satisfaction with current knee function (median 7 (6-8) vs 8 (7-9), p < 0.001). Patients with revision ACLR also experienced greater limitation in sports (median 7 (4-8) vs 8 (6-9), p < 0.001). There were no significant differences in the EQ-5D (mean 0.86 ± 0.17 vs 0.89 ± 0.11, p = 0.427), activity level (median 2 (2-5) vs 4 (2-7), p = 0.229), or satisfaction with activity level (median 8 (5-9) vs 8 (6-10), p = 0.281) between the groups.

CONCLUSIONS

At a minimum 5-year follow-up, the revision ACLR group reported poorer knee function and quality of life, less satisfaction with knee function and a greater limitation in sports but no differences in activity level and satisfaction with activity level compared with the primary ACLR group.

Players', Head Coaches', And Medical Personnels' Knowledge, Understandings and Perceptions of Injuries and Injury Prevention in Elite-Level Women's Football in Ireland

BACKGROUND

To manage injuries effectively, players, head coaches, and medical personnel need to have excellent knowledge, attitudes, and behaviours in relation to the identification of risk factors for injuries, the implementation of injury prevention initiatives, as well as the implementation of effective injury management strategies. Understanding the injury context, whereby specific personal, environmental, and societal factors can influence the implementation of injury prevention initiatives and injury management strategies is critical to player welfare. To date, no qualitative research investigating the context of injuries, has been undertaken in elite-level women's football. The aim of our study was to explore the knowledge, attitudes, and behaviours of players, head coaches, and medical personnel in the Irish Women's National League (WNL) to injury prevention and injury management.

METHODS

We used qualitative research methods to explore the knowledge, attitudes, and behaviours of players, head coaches, and medical personnel in the Irish WNL to injury prevention and injury management. Semi-structured interviews were undertaken with 17 players, 8 medical personnel, and 7 head coaches in the Irish WNL. The data were analysed using thematic analysis. Our study is located within an interpretivist, constructivist research paradigm.

RESULTS

The participants had incomplete knowledge of common injuries in elite-level football, and many held beliefs about risk factors for injuries, such as menstrual cycle stage, which lacked evidence to support them. Jumping and landing exercises were commonly used to reduce the risk of injuries but evidence-based injury prevention exercises and programmes such as the Nordic hamstring curl, Copenhagen adduction exercise, and the FIFA 11+ were rarely mentioned. Overall, there was dissatisfaction amongst players with their medical care and strength and conditioning (S & C) support, with resultant inadequate communication between players, head coaches, and medical personnel.

CONCLUSION

Poor quality and availability of medical care and S & C support were considered to be a major obstacle in the effective implementation of injury risk reduction strategies and successful return-to-sport practices. More original research is required in elite-level women's football to explore injury risk factors, injury prevention initiatives, and contextual return-to-sport strategies, so that players, head coaches, and medical personnel can use evidence that is both up-to-date and specific to their environment.

The side hop test: Validity, reliability, and quality aspects in relation to sex, age and anterior cruciate ligament reconstruction, in soccer players

OBJECTIVE

To study the side hop test regarding validity, reliability, and quality in relation to sex, age and ACL-reconstruction in soccer players.

DESIGN

Cohort study.

PARTICIPANTS

117 females with a primary ACL-reconstruction, and 119 females, 46 males (age 16-26 years), 49 girls and 66 boys (age 13-16 years) without injury.

MAIN OUTCOME MEASURES

For convergent validity, one physiotherapist analysed side hops live and later on video. One physiotherapist and two physiotherapy students analysed side hops from 92 players for interrater reliability (video). For intrarater reliability, side hops from 35 players were analysed twice (video). Quality aspects (flaws), i.e. number of times the hopping limb touched the strips, the non-hopping limb touched the floor, and double hops/foot turns with the hopping limb, were registered (video).

RESULTS

Convergent validity was excellent; the intraclass correlation coefficient (ICC) was 0.93-1.0. All reliability measures were excellent (ICC 0.92-1.0). Adult male players had fewest and girls had most flaws, especially double hops/foot turns with the hopping limb, compared with all other players (mean, 11-12 vs 1-6, η² = 0.18, large effect size). No differences were reported between knee-healthy and ACL-reconstructed females.

CONCLUSION

The side hop test is valid and reliable. Quality aspects differ between sexes and ages.

Risk Factors for Sustaining a Second ACL Injury after Primary ACL Reconstruction in Female Football Players: A Study Investigating the Effects of Follow-Up Time and the Statistical Approach

BACKGROUND

Studies evaluating risk factors for sustaining an anterior cruciate ligament (ACL) injury have different, sometimes contrasting, results. Different follow-up times and statistical approaches may be a reason for these differences. The aim of this study was to explore if different follow-up times and statistical approaches, classification and regression tree (CART) analysis and Cox regression, would impact on the association between various candidate risk factors and ACL injury in female football players. In total, 112 active female football players, 18 ± 8 months after ACL reconstruction (mean age ± SD, 20 ± 2 years), were included and followed for at least 36 months. At baseline, all players underwent assessment of range of motion of knee and ankle joints, functional tests, and answered questionnaires regarding knee function, psychological and personality traits. Nineteen independent variables were included for the CART analysis and for univariable Cox regression and compared using four different follow-up times: 0-12, 0-24, 0-36, and 0->36 months.

RESULTS

Forty-three (38%) players sustained a second ACL injury. The identified risk factors varied depending on follow-up time both with CART analysis and with Cox regression. CART identified 12 of the 19 independent variables and selected between 5 and 6 of the variables in the four different follow-up times associated with second ACL injury. The accuracy of the different follow-up times for the CART varied between 86 and 93% with 77-96% sensitivity and 70-81% specificity. Cox regression identified two risk factors: knee extension at 0-36 months and 0->36 months, and time between primary injury and surgery at 0->36 months. The accuracy varied between 54 and 64% with 44-88% sensitivity and 32-71% specificity.

CONCLUSIONS

The identified risk factors associated with a second ACL injury varied depending on the follow-up time and statistical approach used. Thus, in future research on risk factors, the time athletes are followed up and the type of statistical methods used are important to discuss.

Intrinsic Risk Factors for First-Time Noncontact ACL Injury: A Prospective Study of College and High School Athletes

BACKGROUND

A comprehensive understanding of the intrinsic risk factors for anterior cruciate ligament (ACL) disruption is important for identifying individuals at increased risk for suffering this trauma and developing interventions to mitigate risk.

HYPOTHESIS

A variety of risk factors predispose athletes to first-time, noncontact ACL injury and some of these differ between male and female athletes.

STUDY DESIGN

Prospective cohort study with nested case-control sampling.

LEVEL OF EVIDENCE

Level 2.

METHODS

Sport teams at 28 high schools and 8 colleges were monitored prospectively over 4 years, and 109 of 130 athletes who suffered their first noncontact ACL injury participated in the study. At the time of injury, matched control subjects were randomly selected from among the case's teammates and a total of 227 athletes participated. Demographic characteristics, joint laxity, lower extremity alignment, strength, and personality characteristics were measured. The association of each risk factor with injury risk was assessed by conditional logistic regression.

RESULTS

The risk factors that were associated with ACL injury in both male and female athletes included having a parent with prior ACL injury and increases of the following variables: body weight, anterior displacement of the tibia relative to the femur, genu recurvatum, and generalized joint laxity. Risk factors that are unique to female athletes included increased body mass index, increased trunk flexion strength, and prior non-ACL knee injury. The risk factors specific to male athletes were decreased standing quadriceps angle, decreased hip adduction strength, and chronic disease.

CONCLUSION

A diverse set of risk factors predispose both male and female athletes to ACL injury, whereas others appear to be sex-specific.

CLINICAL RELEVANCE

Different approaches for assessing risk and preventing ACL injury are needed for male and female athletes. In addition, personalized prevention strategies may be needed to target the specific characteristics that place an individual at increased risk of suffering this trauma.

The experience and influence of fear after anterior cruciate ligament reconstruction: an interview study with young athletes

BACKGROUND

Despite good physical function, many athletes do not return to sports after an anterior cruciate ligament reconstruction (ACLR). One important reason for this is fear of new injury. The aim of this study was to investigate young athletes' experiences of knee-related fear after an ACLR and how they perceive this fear to affect them in their sporting and everyday life.

METHODS

A qualitative interview study was conducted, using semi-structured interviews. Athletes who were active in contact or pivoting sport before an ACL injury, with the goal of returning to the same sport and who scored highly on fear of new injury at six months post-ACLR, were asked to participate. Ten athletes (six women and four men, aged 17-25 years), were interviewed by an independent researcher, 7-9 months after ACLR. Content analysis employing an abductive approach was used.

RESULTS

The analysis resulted in three categories with associated subcategories: 1. The expressions of fear; (i) reason for fear, (ii) changes in fear over time, and (iii) injury situation. 2. Reactions, consequences, and adaptations; (i) reactions, (ii) behavioural adaptation and influence on rehabilitation and daily life, (iii) present consequences, and (iv) consequences for the future. 3. Fear and adaptations related to returning to sports; (i) fear related to returning to sports and, (ii) adaptations in sports and life due to fear. Fear was described in broad and complex ways, with fear of a new injury being expressed as one of several aspects. Various reasons (e.g., seeing others getting injured in the past, previous experience of injury, failed rehabilitation, perceived knee instability) were given to explain the fear, and athletes reacted both physically and mentally to fear. Both positive and negative adaptations to fear were described, in both daily life and sports.

CONCLUSION

The results contribute to an increased understanding of fear as an essential psychological factor to consider during rehabilitation and leaves the way open for research to investigate how physiotherapists can work to manage fear better among ACLR patients.

The Swedish version of the Anterior Cruciate Ligament Quality Of Life measure (ACL-QOL): translation and measurement properties

PURPOSE

To translate the ACL-QOL from English to Swedish and evaluate measurement properties for use after surgical and non-surgical management of anterior cruciate ligament (ACL) injury.

METHODS

The ACL-QOL was translated from English to Swedish and data were pooled from 13 cohorts to enable a comprehensive evaluation of measurement properties in line with COSMIN guidelines. We evaluated internal consistency, test-re-test reliability, measurement error, structural validity [confirmatory factor analysis (CFA)], construct validity and responsiveness (hypothesis testing), and floor/ceiling effects. Results were stratified by time since injury (≤ 1.5 years; 2-10 years, 15-25 years; > 30 years) and ACL management strategy [surgical (n = 1163), non-surgical (n = 570)].

RESULTS

The Swedish ACL-QOL had sufficient internal consistency (total and domain scores) for use in surgically managed (Cronbach's alpha ≥ 0.744) and non-surgically managed (≥ 0.770) ACL-injured individuals at all time-points. Test-re-test reliability was sufficient [intraclass correlation coefficients: all domains > 0.80, total score 0.93 (95% CI 0.86-0.96)]. The standard error of measurement was 5.6 for the total score and ranged from 7.0 to 10.3 for each domain. CFA indicated sufficient SRMR values when using the total score or five domains; however, CFI and RMSEA values did not meet cut-offs for good model fit. Hypothesis testing indicated sufficient construct validity and responsiveness. Floor effects were negligible and ceiling effects were negligible or minor.

CONCLUSION

The Swedish version of the ACL-QOL has sufficient internal consistency, test-re-test reliability, construct validity and responsiveness, for use in people with ACL injury managed with or without ACL surgery. Model fit could be improved and investigation into the source of misfit is warranted.

Repeat Anterior Cruciate Ligament Injury and Return to Sport in Australian Soccer Players After Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autograft

BACKGROUND

Soccer is the most commonly played team sport in the world and a high-risk sport for anterior cruciate ligament (ACL) injury and subsequent ACL reconstruction (ACLR).

PURPOSE

To assess the rate of further ACL injury in patients who have undergone ACLR with hamstring tendon autograft after soccer injuries in Australia and to determine factors associated with repeat ACL injury and return to soccer.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

From a prospectively collected database, a series of 1000 consecutive ACLRs using hamstring autografts performed in soccer players were identified. Patients were surveyed at a minimum 5 years after reconstruction, including details of further ACL injuries to either knee, return to soccer or other sports, and psychological readiness per the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) scale.

RESULTS

Of the 862 participants reviewed, ACL graft rupture occurred in 85 (10%) and contralateral ACL rupture in 68 (8%) within 5 years after the reconstruction. The 5-year ACL graft survivorship was 94% for females and 88% for males. The survivorship of the contralateral ACL was 92% for males and 90% for females. When compared with those aged >25 years, the odds of ACL graft rupture was increased by 4 to 5 times in those aged 19 to 25 years and 3 to 7 times in those ≤18 years. Further ACL injury to the graft or contralateral knee occurred in 44% of males aged ≤18 years. Risk factors for further ACL injury were younger age at time of surgery, male sex, and return to soccer. Graft diameter did not influence ACL graft rupture rates, and 70% of patients returned to soccer after ACLR. The mean ACL-RSI score was 59, and patients who reported more fear of reinjury on this scale were less likely to have returned to soccer.

CONCLUSION

The prevalence of ACL graft rupture (10%) and contralateral ACL rupture (8%) was near equivalent over 5 years in this large cohort of mostly recreational Australian soccer players. ACLR with hamstring autograft is a reliable procedure, allowing 70% of patients to return to soccer in this high-risk population. Risk factors for further ACL injury are progressively younger age at time of surgery, male sex, and return to soccer. Graft diameter was not a factor in ACL graft rupture, indicating that other factors, particularly age, are of primary importance.

Quantitative evaluation of the tibiofemoral joint cartilage by T2 mapping in patients with acute anterior cruciate ligament injury vs contralateral knees: results from the subacute phase using data from the NACOX study cohort

OBJECTIVE

Immediate cartilage structural alterations in the acute phase after an anterior cruciate ligament (ACL) rupture may be a precursor to posttraumatic osteoarthritis (PTOA) development. Our aim was to describe changes in cartilage matrix in the subacute phase of the acutely ACL-injured knee compared to the contralateral uninjured knee.

DESIGN

Participants (n = 118) aged 15-40 years with an acute ACL injury were consecutively included in subacute phase after acute ACL-injury and underwent MRI (mean 29 days post trauma) of both knees. Mean T2 relaxation times, T2 spatial coefficient of variation and cartilage thickness were determined for different regions of the tibiofemoral cartilage. Differences between the acutely ACL-injured and uninjured knee were evaluated using Wilcoxon signed-rank test.

RESULTS

T2 relaxation time in injured knees was increased in multiple cartilage regions from both medial and lateral compartment compared to contralateral knees, mostly in medial trochlea and posterior tibia (P-value<0.001). In the same sites of injured knees, we observed significantly thinner cartilage. Moreover, injured knees presented shorter T2 relaxation time in superficial cartilage on lateral central femur and trochlea (P-value<0.001), and decreased T2 spatial coefficient of variation in lateral trochlea and load bearing regions of medial-central femoral condyle and central tibia in both compartments.

CONCLUSION

Small but statistically significant differences were observed in the subacute phase between ACL-injured and uninjured knee in cartilage T2 relaxation time and cartilage thickness. Future longitudinal observations of the same cohort will allow for better understanding of early development of PTOA.

TRIAL REGISTRATION NUMBER

NCT02931084.

The Problem of Recurrent Injuries in Collegiate Track and Field

Background

As with most sports, participating in Track and Field (T&F) has inherent injury risks and a previous injury often predisposes athletes to a greater future injury risk. However, the frequency and burden of recurrent injuries in collegiate T&F have not been closely examined.

Purpose

The purpose of this study was to describe the frequency and burden of recurrent injuries in collegiate T&F and compare differences in the time loss associated with initial and recurrent injuries by sex and T&F discipline.

Study Design

Descriptive Epidemiology Study.

Methods

Data from the NCAA Injury Surveillance Program were analyzed to describe the frequency and burden of recurrent injuries in collegiate T&F between 2009 and 2014. Comparisons of recurrent injury proportions by T&F discipline were made using Injury Proportion Ratios (IPR) and injury-associated time loss comparisons by injury type and sex were made using Negative Binomial Regression.

Results

Four hundred and seventy-four injuries were reported, 13.1% of which were classified as recurrent injuries. T&F athletes who competed in jumps experienced a lower proportion of recurrent injuries (6.1%) than runners (14.6%) and throwers (19.2%) (Recurrent IPR 0.40, 95% CI 0.18-0.88, p<0.05). When controlling for sex and injury diagnosis, T&F athletes experienced 50% greater time loss from sport following a recurrent injury than an initial injury (95% CI 17%-107%, p<0.01).

Conclusions

Recurrent injuries in T&F athletes account for greater time loss than initial injuries, despite sex or injury diagnosis. The current study indicates a need for further research to assess factors contributing to time loss.

Level of Evidence

Level 3.

Comparison of Knee Function and Activity Level Between Bilateral and Unilateral ACL Reconstruction: A Matched-Group Analysis With Minimum 5-Year Follow-up

Background:

There is a lack of knowledge regarding knee function and activity level after bilateral anterior cruciate ligament reconstruction (ACLR) at midterm follow-up.

Purpose:

To compare activity level, patient-reported knee function, and quality of life in patients with bilateral ACLR and matched controls with unilateral ACLR at a minimum 5-year follow-up.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients with bilateral ACLR who were aged ≤40 years and had a second ACLR performed between 2010 and 2015 were identified in the authors’ local database. Surgical data and preoperative Knee injury and Osteoarthritis Outcome Score (KOOS) were extracted. The patients were sent a letter with questionnaires including the KOOS, EuroQol 5-Dimensions (EQ-5D), and EuroQol visual analog scale (EQ-VAS) and were asked study-specific questions by telephone regarding activity level and knee function at a minimum 5-year follow-up. For every patient with bilateral ACLR, a control matched for age ±2 years, sex, year ACLR was performed, and preinjury activity level or sport at the time of injury were identified in the database.

Results:

A total of 98 patients (mean age ± SD, 33.3 ± 7.3 years) with bilateral ACLR and 98 patients with unilateral ACLR (mean age ± SD, 33.1 ± 7.7 years) were included. The mean postoperative follow-up was 7.6 ± 1.8 years (from the second ACLR) for patients with bilateral ACLR and 7.8 ± 1.7 years for patients with unilateral ACLR. Patients with bilateral ACLR reported lower scores on all KOOS subscales, the EQ-5D, and the EQ-VAS at follow-up (P < .05). There was no difference in activity level between the groups at follow-up, but patients with bilateral ACLR were less satisfied with their activity level and knee function (P < .05).

Conclusion:

Patient-reported knee function and health-related quality of life were inferior in patients with bilateral ACLR compared with patients with unilateral ACLR. Patients with bilateral ACLR cannot expect the same knee function and quality of life as patients with unilateral ACLR.

Fear of Movement and Reinjury in Sports Medicine: Relevance for Rehabilitation and Return to Sport

Athletes are defined by their ability to move and are often accustomed to pain as it relates to their sports and exercise regime. The forced movement restriction and pain associated with an acute or overuse injury has a profound effect not only on their physical abilities but also on their psychological well-being and social context. With the goal of returning to sport, the rehabilitation focus historically has been on recovery of physical attributes, but more recent research is addressing the psychological factors. This Perspective proposes that-according to the current evidence in sports medicine-the fear that affects choice of treatment, rehabilitation, and return to sports is intertwined with physical capacity and recovery of function. Past injury is also 1 of the main risk factors for a sports injury; therefore, fear of reinjury is not irrational. For an athlete, the fear related to a sports injury encompasses the fear of reinjury along with fear of not being able to return to the sport at their highest performance level-and the fear of having lifelong debilitating pain and symptoms. This Perspective reviews the evidence for the influence of fear of movement and reinjury on choice of treatment, rehabilitation, and return to sport and provides suggestions on how to address this fear during the continuum of treatment and return to sports.

Landing biomechanics deficits in anterior cruciate ligament reconstruction patients can be assessed in a non-laboratory setting

Landing biomechanics provide important information pertaining to second anterior cruciate ligament (ACL) injury risk in patients following ACL reconstruction (ACLR). While traditional motion analysis technologies are often impractical for use in non-laboratory settings, methods to assess landing biomechanics which are inexpensive, portable, and user-friendly have recently been developed and validated. The purpose of this study was to compare landing kinematics and kinetics between ACLR patients and uninjured controls in a non-laboratory setting. Sixteen ACLR patients (7 male/9 female, 6-12 months post-ACLR) and 16 gender-matched controls completed seven bilateral drop vertical jumps and seven unilateral drop landings on each limb. Plantar force was measured bilaterally using force sensing insoles and frontal and sagittal-plane knee kinematics were measured using two tablets, six reflective markers, and automated point tracking software. Plantar force impulse normalized symmetry index (NSI) and knee frontal plane projection angle (FPPA) range of motion were computed during bilateral landing, and knee flexion range of motion NSI was computed during unilateral landing and compared between groups using independent samples t tests. ACLR patients had larger NSIs (reflecting less symmetry) for plantar force impulse during bilateral landing (p < 0.001) and knee flexion range of motion during unilateral landing (p = 0.004). No between-group differences were observed for knee FPPA range of motion (p = 0.111). This study is an important step towards assessing landing biomechanics in non-research settings with the goal of providing quantitative injury risk metrics in a clinical setting that can be used for return to sport decision making.

Predictors of patient satisfaction after primary hamstring anterior cruciate ligament reconstruction

BACKGROUND

Predictors of patient satisfaction (PS) after anterior cruciate ligament (ACL) reconstruction are not well known. This study investigated predictors of PS and whether PS was associated with pre-injury level of sport participation, patient reported knee function and quality of life after ACL reconstruction.

METHODS

Patients who underwent primary hamstring ACL reconstruction between January 2015 and December 2017 were retrospectively evaluated. An online survey was used to evaluate PS (yes = satisfied, no = unsatisfied), duration of supervised postoperative rehabilitation, timing of return to pre-injury level of sport, pre-injury level of sport participation, patient reported knee function and quality of life. Preoperative, operative and postoperative variables were collected from the medical records.

RESULTS

A total of 183 patients completed the survey at a median of 3.6 (1.5) years after ACL surgery. At final follow-up, 82% of patients were satisfied with the outcome. Preoperative (e.g. age) and operative (e.g. meniscal tear) variables were not predictors of PS (p > 0.05). Duration of supervised postoperative rehabilitation, timing of return to pre-injury level of sport and postoperative ACL injury were predictors of PS (p = 0.018, p = 0.016 and p < 0.001, respectively). Pre-injury level of sport participation was significantly higher in satisfied compared to unsatisfied patients: 44.7% (n = 67) versus 18.2% (n = 6) (p = 0.005). In addition, satisfied patients reported significantly higher patient reported knee function and quality of life compared to unsatisfied patients (p < 0.001).

CONCLUSION

This study provided data on predictors of PS after primary ACL reconstruction. Furthermore, PS was associated with pre-injury level of sport participation, patient reported knee function and quality of life.

Fear of Reinjury Following Surgical and Nonsurgical Management of Anterior Cruciate Ligament Injury: An Exploratory Analysis of the NACOX Multicenter Longitudinal Cohort Study

OBJECTIVES

The purpose of this study was to compare fear and certainty of reinjury between follow-up time points and treatment groups (no anterior cruciate ligament [ACL] reconstruction [no ACLR], pre-ACLR, post-ACLR) and to identify prognostic factors for fear of reinjury at 3 and 12 months following injury or ACLR.

METHODS

An exploratory analysis of the Natural Corollaries and Recovery After ACL-injury multicenter longitudinal cohort study was conducted. Patients (n = 275) with primary ACL injury and 15 to 40 years of age received usual care (initial physical therapist-supervised rehabilitation, before considering ACLR). Fear of reinjury (as measured with the Anterior Cruciate Ligament Quality of Life instrument [ACL-QOL] item 31 and the Anterior Cruciate Ligament Return to Sport After Injury instrument [ACL-RSI] item 9) and certainty of reinjury (as measured with the Knee Self-Efficacy Scale item D2) were evaluated at baseline and at 3, 6, and 12 months following ACL injury or ACLR. Comparisons were performed with linear mixed models. Linear regression assessed potential prognostic factors (age, sex, preinjury activity, baseline knee function, baseline general self-efficacy, and expected recovery time) for fear of reinjury (ACL-QOL item 31) at the 3- and 12-month follow-up assessments.

RESULTS

Fear of reinjury was common regardless of ACL treatment. Fear of reinjury decreased between 3 and 6 months and 3 and 12 months (mean difference: ACL-QOL = 9 [95% CI = 2 to 15]; ACL-RSI = 21 [95% CI = 13 to 28]) after injury. This improvement was not observed in patients who later underwent ACLR, who reported worse fear of reinjury at 3 months (ACL-QOL = 10 [95% CI = 3 to 18]) and at 12 months (ACL-RSI = 22 [95% CI = 2 to 42]) postinjury compared with those who did not proceed to ACLR. Following ACLR, fear of reinjury decreased between the 3- and 12-month follow-up assessments (ACL-QOL = 10 [95% CI = 4 to 16]; ACL-RSI = 12 [95% CI = 5 to 19]). Greater baseline general self-efficacy was associated with reduced fear of reinjury at 12 months after injury (adjusted coefficient = 1.7 [95% CI = 0.0 to 3.5]). Female sex was related to more fear of reinjury 3 months after ACLR (-14.5 [95% CI = -25.9 to -3.1]), and better baseline knee function was related to reduced fear of reinjury 12 months after ACLR (0.3 [95% CI = 0.0 to 0.7]).

CONCLUSION

People who had ACLR reported worse fear of reinjury before surgery than those who did not proceed to ACLR. Different prognostic factors for fear of reinjury were identified in people treated with ACLR and those treated with rehabilitation alone.

IMPACT

Fear of reinjury is a concern following ACL injury. Clinicians should evaluate and address reinjury fears. These results may assist in identifying individuals at risk of fear of reinjury following surgical and nonsurgical management of ACL injury.

Exercise-Based Training Strategies to Reduce the Incidence or Mitigate the Risk Factors of Anterior Cruciate Ligament Injury in Adult Football (Soccer) Players: A Systematic Review

Anterior cruciate ligament (ACL) is one of the most concerning injuries for football players. The aim of this review is to investigate the effects of exercise-based interventions targeting at reducing ACL injury rate or mitigating risk factors of ACL injury in adult football players. Following PRISMA guidelines, a systematic search was conducted in CINAHL, Cochrane Library, PubMed, Scopus, SPORTDiscus and Web of Science. Studies assessing the effect of exercise-based interventions in ACL injury incidence or modifiable risk factors in adult football players were included. 29 studies evaluating 4502 male and 1589 female players were included (15 RCT, 8 NRCT, 6 single-arm): 14 included warm-up, 7 resistance training, 4 mixed training, 3 balance, 1 core stability and 1 technique modification interventions. 6 out of 29 studies investigated the effect of interventions on ACL injury incidence, while the remaining 23 investigated their effect on risk factors. Only 21% and 13% studies evaluating risk of injury variables reported reliability measures and/or smallest worthwhile change data. Warm-up, core stability, balance and technique modification appear effective and feasible interventions to be included in football teams. However, the use of more ecologically valid tests and individually tailored interventions targeting specific ACL injury mechanisms are required.

High Risk of New Knee Injuries in Female Soccer Players After Primary Anterior Cruciate Ligament Reconstruction at 5- to 10-Year Follow-up

BACKGROUND

A new anterior cruciate ligament (ACL) injury after ACL reconstruction is a feared outcome.

PURPOSE

To study the risk of new knee injuries in female soccer players 5 to 10 years after primary unilateral ACL reconstruction and to compare players who returned to soccer with (1) players who did not return and (2) knee-healthy soccer players (controls).

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Demographic, soccer-specific, and surgical data were recorded at baseline for 317 female soccer players (mean ± SD age, 20.1 ± 2.7 years) 1.6 ± 0.7 years after ACL reconstruction and for 119 matched controls (mean age, 19.5 ± 2.5 years). Data on new knee injuries and soccer-playing status were collected 5 to 10 years after ACL reconstruction via a questionnaire.

RESULTS

Among players with ACL reconstruction, 222 (70%) responded at a mean 6.5 ± 1.0 years after primary ACL reconstruction. We compared 3 cohorts: (1) among 163 players with ACL reconstruction who returned to soccer, 68 (42%) sustained 44 reruptures and 29 contralateral ruptures; (2) among 59 players with ACL reconstruction who did not return to soccer, 11 (19%) sustained 9 reruptures and 2 contralateral ruptures; and (3) among 113 knee-healthy controls, 12 (11%) sustained 13 ACL injuries. Players who returned had a >2-fold higher risk of a new ACL injury than players who did not return (risk ratio, 2.24; 95% CI, 1.27-3.93; P = .005) and a 4-fold higher risk than controls (risk ratio, 3.93; 95% CI, 2.23-6.91; P <.001). A new ACL, meniscal, or cartilage injury was the most frequent new knee injury. Among players who returned to soccer, 68% reported a new knee injury, and they had a 2- to 5-times higher risk of any new knee injury and knee surgery than players who did not return and controls.

CONCLUSION

Two-thirds of female soccer players with ACL reconstruction who returned to soccer sustained a new knee injury within 5 to 10 years; 42% had a new ACL injury. Their risk of a new knee injury and knee surgery was 2 to 5 times greater than that for players who did not return and for knee-healthy controls. New injury may have negative consequences for long-term knee health and should be a critical consideration in the decision to return to play.

The dominant leg is more likely to get injured in soccer players: systematic review and meta-analysis

In soccer (football), dominant limb kicking produces higher ball velocity and is used with greater frequency than the non-dominant limb. It is unclear whether limb dominance has an effect on injury incidence. The purpose of this systematic review with meta-analysis is to examine the relationship between limb dominance and soccer injuries. Studies were identified from four online databases according to PRISMA guidelines to identify studies of soccer players that reported lower extremity injuries by limb dominance. Relevant studies were assessed for inclusion and retained. Data from retained studies underwent meta-analyses to determine relative risk of dominant versus non-dominant limb injuries using random-effects models. Seventy-four studies were included, with 36 of them eligible for meta-analysis. For prospective lower extremity injury studies, soccer players demonstrated a 1.6 times greater risk of injury to the dominant limb (95% CI [1.3-1.8]). Grouped by injury location, hamstring (RR 1.3 [95% CI 1.1-1.4]) and hip/groin (RR 1.9 [95% CI 1.3-2.7]) injuries were more likely to occur to the dominant limb. Greater risk of injury was present in the dominant limb across playing levels (amateurs RR 2.6 [95% CI 2.1-3.2]; youths RR 1.5 [95% CI 1.26-1.67]; professionals RR 1.3 [95% CI 1.14-1.46]). Both males (RR 1.5 [95% CI 1.33-1.68)] and females (RR 1.5 [95% CI 1.14-1.89]) were more likely to sustain injuries to the dominant limb. Future studies investigating soccer injury should adjust for this confounding factor by using consistent methods for assigning limb dominance and tracking use of the dominant versus non-dominant limb.

Sensor-Based Indices for the Prediction and Monitoring of Anterior Cruciate Ligament Injury: Reliability Analysis and a Case Study in Basketball

The possibility of measuring predictive factors to discriminate athletes at higher risk of anterior cruciate ligament (ACL) injury still represents an open research question. We performed an observational study with thirteen female basketball players who performed monopodalic jumps and single-leg squat tests. One of them suffered from an ACL injury after the first test session. Data gathered from twelve participants, who did not suffer from ACL injury, were used for a reliability analysis. Parameters related to leg stability, load absorption capability and leg mobility showed good-to-excellent reliability. Path length, root mean square of the acceleration and leg angle with respect to the vertical axis revealed themselves as possible predictive factors to identify athletes at higher risk. Results confirm that six months after reconstruction represents the correct time for these athletes to return to playing. Furthermore, the training of leg mobility and load absorption capability could allow athletes to reduce the probability of new injuries.

Rehabilitation Principles to Consider for Anterior Cruciate Ligament Repair

CONTEXT

Injury to the anterior cruciate ligament (ACL) is among the most common orthopaedic injuries, and reconstruction of a ruptured ACL is a common orthopaedic procedure. In general, surgical intervention is necessary to restore stability to the injured knee, and to prevent meniscal damage. Along with surgery, intense postoperative physical therapy is needed to restore function to the injured extremity. ACL reconstruction (ACLR) has been the standard of care in recent decades, and advances in surgical technology have reintroduced the prospect of augmented primary repair of the native ACL via a variety of methods.

EVIDENCE ACQUISITION

A search of PubMed database of articles and reviews available in English was performed through 2020. The search terms ACLR, anterior cruciate ligament repair, bridge enhanced acl repair, suture anchor repair, dynamic intraligamentary stabilization, internal bracing, suture ligament augmentation, and internal brace ligament augmentation were used.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 5.

RESULTS

No exact consensus exists on effective rehabilitation protocols after ACL repair techniques, as the variation in published protocols seem even greater than the variation in those for ACLR. For some techniques such as internal bracing and dynamic interligamentary stabilization, it is likely permissible for the patients to progress to full weightbearing and discontinue bracing sooner. However, caution should be applied with regard to earlier return to sport than after ACLR as to minimize risk for retear.

CONCLUSION

More research is needed to address how physical therapies must adapt to these innovative repair techniques. Until that is accomplished, we recommend that physical therapists understand the differences among the various ACL surgery techniques discussed here and work with the surgeons to develop a rehabilitation protocol for their mutual patients.

STRENGTH OF RECOMMENDATION TAXONOMY (SORT)

C.

Poor Validity of Functional Performance Tests to Predict Knee Injury in Female Soccer Players With or Without Anterior Cruciate Ligament Reconstruction

BACKGROUND

Various tests have been developed to evaluate athletes' functional performance and for use as screening tools for injury prediction. Further validation of their accuracy to predict injury is needed.

PURPOSE

To investigate the validity of predetermined cutoffs used to differentiate between high- and low-risk players in different functional performance tests to predict (1) anterior cruciate ligament (ACL) injury or (2) severe traumatic knee injury in a cohort of female soccer players with a primary unilateral ACL reconstruction and a cohort of knee-healthy players.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 117 active female soccer players (mean age ± SD, 20 ± 2 years) an average of 19 ± 9 months after ACL reconstruction and 119 knee-healthy players (age, 19 ± 3 years) were prospectively followed up for 2 years for new knee injuries. At baseline, all players underwent tests to assess postural control (Star Excursion Balance Test), hop performance (single-leg hop for distance, side hop), and movement asymmetries in the lower limbs and trunk (drop vertical jump [DVJ], tuck jump). The predictive validity of the test cutoffs to identify players who would sustain an ACL injury or a severe traumatic knee injury (absence from soccer play, >28 days) was assessed. The risk ratio (RR), area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were calculated.

RESULTS

A total of 46 players (39%) with ACL reconstruction sustained 48 severe knee injuries, including 28 ACL ruptures. Of the knee-healthy players, 13 (11%) sustained 14 severe knee injuries, including 8 ACL ruptures. No association was found between the predetermined functional performance test cutoffs and the risk of a new ACL injury or severe knee injury in players with ACL reconstruction. In knee-healthy players, the only variable associated with future ACL injury was ≥6.5 cm knee valgus in the frontal plane (any knee) in the DVJ (RR, 4.93; 95% CI, 1.04-23.40; P = .045), but with only fair predictive validity (AUC, 0.7; sensitivity, 0.75; specificity, 0.65).

CONCLUSION

In our cohorts of female soccer players, the validity of commonly used functional performance tests to predict new knee injuries was poor. Only knee valgus during the DVJ was associated with new ACL injuries in knee-healthy players, but with only fair predictive validity.

Clinical Risk Profile for a Second Anterior Cruciate Ligament Injury in Female Soccer Players After Anterior Cruciate Ligament Reconstruction

BACKGROUND

The risk of a second anterior cruciate ligament (ACL) injury when participating in pivoting sports after ACL reconstruction is high. Risk factors associated with a second ACL injury are complex.

PURPOSE

To investigate the combinations of various clinical risk factors associated with second ACL injury in female soccer players with a primary unilateral ACL reconstruction, using Classification and Regression Tree (CART) analysis.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 117 active female soccer players (mean ± SD age, 20 ± 2 years) were included. Athletes were enrolled 19 ± 9 months after ACL reconstruction and were prospectively followed for 2 years. At baseline, all players underwent assessment of knee and ankle joint range of motion (ROM), participated in functional tests (postural control, hop performance, and movement asymmetries in the lower limbs and trunk), and answered questionnaires (patient-reported knee function, knee-related quality of life, psychological and personality factors). A clinical prediction model using CART was developed.

RESULTS

A total of 28 players (24%) sustained a second ACL injury (21 ipsilateral and 7 contralateral ruptures) while playing soccer. CART analysis selected 9 of 19 independent variables associated with second ACL injury: the 5-jump test, knee collapse on the non-ACL reconstructed leg in a drop vertical jump, tuck jump, limb symmetry index on side hop and the single hop for distance, side difference in ankle dorsiflexion ROM, and scores for the questionnaires ACL-Return to Sport After Injury and the Swedish Universities Scales of Personality subscales of Stress Susceptibility and Adventure Seeking. The accuracy of the model was 89%, with 100% sensitivity and 76% specificity. CART analysis indicated that the interaction of longer jumps in the 5-jump test (>916 cm) with more side difference in ankle dorsiflexion ROM (>-2.5°) and more knee valgus collapse in the nonreconstructed knee (>-1.4 cm) (relative risk, 4.03; 95% CI, 2.21-7.36) best predicted an increased likelihood of a second ACL injury.

CONCLUSION

The risk profiles selected by CART could accurately identify female soccer players at high risk for a second ACL injury. There was an interaction between functional performance, clinical assessment, and psychological factors, and it is reasonable to include these factors in return-to-sport decisions and in athlete screening after ACL injury.

High rate of second ACL injury following ACL reconstruction in male professional footballers: an updated longitudinal analysis from 118 players in the UEFA Elite Club Injury Study

Background

Studies on subsequent anterior cruciate ligament (ACL) ruptures and career length in male professional football players after ACL reconstruction (ACLR) are scarce.

Aim

To investigate the second ACL injury rate, potential predictors of second ACL injury and the career length after ACLR.

Study design

Prospective cohort study.

Setting

Men’s professional football.

Methods

118 players with index ACL injury were tracked longitudinally for subsequent ACL injury and career length over 16.9 years. Multivariable Cox regression analysis with HR was carried out to study potential predictors for subsequent ACL injury.

Results

Median follow-up was 4.3 (IQR 4.6) years after ACLR. The second ACL injury rate after return to training (RTT) was 17.8% (n=21), with 9.3% (n=11) to the ipsilateral and 8.5% (n=10) to the contralateral knee. Significant predictors for second ACL injury were a non-contact index ACL injury (HR 7.16, 95% CI 1.63 to 31.22) and an isolated index ACL injury (HR 2.73, 95% CI 1.06 to 7.07). In total, 11 of 26 players (42%) with a non-contact isolated index ACL injury suffered a second ACL injury. RTT time was not an independent predictor of second ACL injury, even though there was a tendency for a risk reduction with longer time to RTT. Median career length after ACLR was 4.1 (IQR 4.0) years and 60% of players were still playing at preinjury level 5 years after ACLR.

Conclusions

Almost one out of five top-level professional male football players sustained a second ACL injury following ACLR and return to football, with a considerably increased risk for players with a non-contact or isolated index injury.

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.

Short-term recovery of physical activity and knee function after an acute knee injury

Objectives

To describe self-reported knee function, participation in physical activity and the number of knee surgeries at 3 and 6 months following acute knee injury.

Methods

Prospective cohort study. Participants, aged 15–40 years with an acute knee injury sustained no more than 6 weeks prior to inclusion, were recruited. There were 279 participants with ACL injury and 101 participants with other acute knee injuries included. Follow-up questionnaires were sent at 3 and 6 months after injury. Demographic information, activity participation, International Knee Documentation Committee subjective knee form (IKDC-SKF) and the Single Assessment Numeric Evaluation (SANE) score were collected. Additional knee injuries were obtained from self-report and medical charts.

Results

The IKDC-SKF, SANE and physical activity participation were reduced at 3-month and 6-month follow-up. The number of participants who achieved health-promoting physical activity levels was reduced by 50% at 6-month follow-up compared with before injury. Seventeen per cent of participants with ACL injury and 41% of participants with other acute knee injuries had returned to their preinjury physical activity at 6 months. Participants with ACL injury reported worse knee function, lower physical activity participation and had more surgeries (128 surgeries, including 109 ACL-reconstructions) compared with participants with other acute knee injuries (six surgeries).

Conclusion

Acute knee injuries, including ACL injuries, affected self-reported knee function and physical activity participation for at least 6 months after index injury. More research is needed to understand how best to help people with acute knee injuries return to physical activity and achieve satisfactory knee function.

The Challenges of Treating Female Soccer Players With ACL Injuries: Hamstring Versus Bone-Patellar Tendon-Bone Autograft

Background:

Although anterior cruciate ligament (ACL) injuries are common in female soccer players, the optimal graft option for ACL reconstruction is currently unclear.

Purpose/Hypothesis:

To compare the outcomes of female soccer players after ACL reconstruction using either hamstring tendon autograft or bone–patellar tendon–bone (BTB) autograft. We hypothesized that there would be no difference in clinical outcome scores, return to sport, or retear rates between BTB and hamstring grafts in our study cohort.

Study Design:

Case series; Level of evidence, 4.

Methods:

We performed a retrospective review of all skeletally mature adolescent female soccer players who underwent primary ACL reconstruction using either hamstring tendon or BTB autograft between 2013 and 2016. Demographic, injury, and surgical variables were documented. Outcome measures included the Lysholm score, Single Assessment Numeric Evaluation, Tegner activity score, and visual analog scales for pain and for satisfaction, as well as ability to return to sport.

Results:

Overall, 90 female soccer players met the inclusion criteria, of whom 79% (41 BTB and 30 hamstring) were available for a minimum 2-year follow-up or had a graft failure before the follow-up. The BTB group had a lower body mass index (mean ± SD, 23 ± 3 vs 25 ± 4; P = .02) and shorter postoperative follow-up time in months (mean ± SD, 37.4 vs 46.1; P ≤ .001); otherwise, no differences in demographic, injury, or surgical variables between groups were noted. Regarding outcome measures, the BTB group achieved a higher Tegner score (6.0 vs 4.2; P = .004), and there was no other difference between groups. Of the patients who did not return to soccer, 44.7% reported fear as the reason. Of the patients who did return to soccer, 31.9% sustained another ACL injury (retear or contralateral tear), with no differences in reinjury rates based on graft selection.

Conclusion:

Adolescent female soccer players undergoing ACL reconstruction had relatively high satisfaction and outcome scores independent of autograft choice. Notwithstanding, patients and families need to be counseled that less than half of patients will return to their preinjury level of sport and, if an athlete attempts to return, there is a high risk of further ACL injury.

Radiographic and Symptomatic Knee Osteoarthritis 32 to 37 Years After Acute Anterior Cruciate Ligament Rupture

BACKGROUND

The long-term prevalence of knee osteoarthritis (OA) after anterior cruciate ligament (ACL) injury is unknown, especially in patients without a history of ACL surgery.

PURPOSE

To (1) describe the prevalence of radiographic OA, symptomatic OA, and knee replacement surgery 32 to 37 years after acute ACL injury and to (2) compare the prevalence of radiographic OA, symptomatic OA, and knee symptoms between patients allocated to early ACL surgery or no ACL surgery and patients who crossed over to ACL surgery.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Participants aged 15 to 40 years at the time of ACL injury were allocated to surgical (augmented or nonaugmented ACL repair) or nonsurgical ACL treatment within 14 days of injury. At 32 to 37 years after the initial injury, 153 participants were followed up with plain weightbearing radiographs and completed 4 subscales from the Knee injury and Osteoarthritis Outcome Score (KOOS). Radiographic OA was defined as Kellgren and Lawrence grade 2 or higher. Symptomatic OA was defined as radiographic OA plus knee symptoms measured with the KOOS.

RESULTS

Participants allocated to ACL surgery (n = 64) underwent surgery at a mean ± SD of 5 ± 4 days (range, 0-11 days) after injury. Of the 89 participants allocated to no ACL surgery, 53 remained nonsurgically treated, 27 had ACL surgery within 2 years, and 9 had ACL surgery between 3 and 21 years after injury. In the total sample, 95 participants (62%) had radiographic tibiofemoral OA, including 11 (7%) who had knee replacement. The prevalence of radiographic tibiofemoral OA was lower in the group allocated to ACL surgery compared with the group who never had ACL surgery (50% vs 75%; P = .005). The prevalence of symptomatic OA (50% in the total sample) and patellofemoral radiographic OA (35% in the total sample) was similar between groups.

CONCLUSION

Patients allocated to early ACL surgery, performed a mean 5 days after injury, had a lower prevalence of tibiofemoral radiographic OA at 32 to 37 years after injury compared with patients who never had ACL surgery. The prevalences of symptomatic OA, radiographic patellofemoral OA, and knee symptoms were similar irrespective of ACL treatment. Overall, the prevalence of OA after ACL injury was high.

REGISTRATION

NCT03182647 (ClinicalTrials.gov identifier).

Linear Discriminant Analysis Successfully Predicts Knee Injury Outcome From Biomechanical Variables

BACKGROUND

The most commonly damaged structures of the knee are the anterior cruciate ligament (ACL), medial collateral ligament (MCL), and menisci. Given that these injuries present as either isolated or concomitant, it follows that these events are driven by specific mechanics versus coincidence. This study was designed to investigate the multiplanar mechanisms and determine the important biomechanical and demographic factors that contribute to classification of the injury outcome.

HYPOTHESIS

Linear discriminant analysis (LDA) would accurately classify each injury type generated by the mechanical impact simulator based on biomechanical input variables (ie, ligament strain and knee kinetics).

STUDY DESIGN

Controlled laboratory study.

METHODS

In vivo kinetics and kinematics of 42 healthy, athletic participants were measured to determine stratification of injury risk (ie, low, medium, and high) in 3 degrees of knee forces/moments (knee abduction moment, anterior tibial shear, and internal tibial rotation). These stratified kinetic values were input into a cadaveric impact simulator to assess ligamentous strain and knee kinetics during a simulated landing task. Uniaxial and multiaxial load cells and implanted strain sensors were used to collect mechanical data for analysis. LDA was used to determine the ability to classify injury outcome by demographic and biomechanical input variables.

RESULTS

From LDA, a 5-factor model (Entropy R2 = 0.26) demonstrated an area under the receiver operating characteristic curve (AUC) for all 5 injury outcomes (ACL, MCL, ACL+MCL, ACL+MCL+meniscus, ACL+meniscus) of 0.74 or higher, with "good" prediction for 4 of 5 injury classifications. A 10-factor model (Entropy R2 = 0.66) improved the AUC to 0.86 or higher, with "excellent" prediction for 5 injury classifications. The 15-factor model (Entropy R2 = 0.85), produced 94.1% accuracy with the AUC 0.98 or higher for all 5 injury classifications.

CONCLUSION

Use of LDA accurately predicted the outcome of knee injury from kinetic data from cadaveric simulations with the use of a mechanical impact simulator at 25° of knee flexion. Thus, with clinically relevant kinetics, it is possible to determine clinical risk of injury and also the likely presentation of singular or concomitant knee injury.

CLINICAL RELEVANCE

LDA demonstrates that injury outcomes are largely characterized by specific mechanics that can distinguish ACL, MCL, and medial meniscal injury. Furthermore, as the mechanics of injury are better understood, improved interventional prehabilitation can be designed to reduce these injuries.

All-Inside Quadrupled Semitendinosus Autograft Shows Stability Equivalent to Patellar Tendon Autograft Anterior Cruciate Ligament Reconstruction: Randomized Controlled Trial in Athletes 24 Years or Younger

PURPOSE

To compare clinical outcomes of knee anterior cruciate ligament (ACL) autograft reconstruction using all-inside quadrupled semitendinosus (AIST) versus bone-patellar tendon-bone (BPTB) in a high-risk athletic population 24 years or younger.

METHODS

Skeletally mature candidates younger than 24 years old with an ACL tear were randomized into either the AIST (n = 32) or BPTB (n = 32) group and were followed for 2 years. Magnetic resonance imaging scans were obtained at 1-year follow-up, and radiographs were obtained at 2-year follow-up. All surgeries were performed by a single surgeon using an anteromedial portal to establish the femoral tunnel. The primary outcome measure was KT-1000 stability testing. Secondary outcome measures included International Knee Documentation Committee (IKDC) Knee Evaluation Form, IKDC Subjective Form, Knee Injury and Osteoarthritis Outcome Score, Marx Activity Scale, visual analog pain scale, and SF-12 (Mental and Physical).

RESULTS

At 2-year follow-up, no statistical difference existed with KT-1000-measured side-to-side laxity between AIST (0.3 ± 0.7 mm, 95% confidence interval 0.0-1.0 mm) and BPTB (0.0 ± 0.8 mm, confidence interval CI -0.3 to 1.1 mm) (P = .197). In addition, no statistical differences between the groups were found for IKDC Subjective Form, Knee Injury and Osteoarthritis Outcome Score, Marx, SF-12 Mental, SF-12 Physical, or with regards to imaging findings. Patients with BPTB reported significantly greater postoperative pain scores at days 2 (P = .049), 3 (P = .004), and 7 (P = .015) and had significantly greater kneeling pain at 2 years (P < .019). A return to sport questionnaire at 2 years revealed no significant difference between the groups for returning to preoperative level of sport activity (83% AIST, 74% BPTB; P = .415). Two graft retears (7%; P = .222) occurred in the AIST group. Three patients in the BPTB group experienced ACL tears in the contralateral knee (9%; P = .239).

CONCLUSIONS

ACL reconstruction with an all-inside quadrupled semitendinosus autograft construct is equivalent to patellar BPTB autograft based on KT-1000 stability testing in athletes 24 years or younger.

LEVEL OF EVIDENCE

randomized controlled trial with 92% 2-year follow-up, Level I.

How Much Time Is Needed Between Serial "Return to Play" Assessments to Achieve Clinically Important Strength Gains in Patients Recovering From Anterior Cruciate Ligament Reconstruction?

BACKGROUND

Pass rates for return-to-play evaluations are alarmingly low for patients after anterior cruciate ligament reconstruction (ACLR). Since timing of return to play is a complicated decision, it is important that patients be given optimal time to realize meaningful improvements in strength that warrant additional testing.

PURPOSE

To (1) compare outcomes among patients assessed at different time points after ACLR, (2) determine strength gains indicative of improvements in subjective function, and (3) determine the amount of time necessary to achieve meaningful strength gains.

STUDY DESIGN

Cross-sectional/case-control study; Level of evidence, 3.

METHODS

A total of 293 patients participated in the study after ACLR (mean ± SD, 23.2 ± 10.1 years old; n = 142 female participants; 6.4 ± 0.9 months after ACLR). Participants were stratified on the month of their evaluation after ACLR: 5 to 6 months (n = 122), 6 to 7 months (n = 102), 7 to 8 months (n = 43), and 8 to 9 months (n = 26). The International Knee Documentation Committee (IKDC) subjective form and knee extensor and flexor torque and symmetry, as assessed through an isokinetic dynamometer, were compared among groups. Forty patients (20 female participants, 20.4 ± 7.1 years old) were referred for subsequent testing (2.14 ± 0.78 months after initial visit). Subjective improvement between visits was defined as a ≥9-point change of the IKDC score. Thresholds of knee extensor torque and symmetry indicative of subjective improvement and the time between assessments needed to achieve these strength improvements were determined.

RESULTS

Patients between 5 and 6 months (IKDC, 79.7; interquartile range [IQR], 70.1-88.5) had lower subjective function compared to patients between 6 and 7 months (IKDC, 83.9; IQR, 74.5-92.0; P = .019) and 8 and 9 months after ACLR (IKDC, 89.1; IQR 75.8-92.3; P = .026). Patients between 5 and 6 months (1.41 N·m/kg; IQR, 1.16-1.73 N·m/kg]) had lower knee extensor torque compared to patients 6 and 7 months (1.59 N·m/kg; IQR, 1.23-1.95 N·m/kg; P = .013) and 7 and 8 months after ACLR (1.62 N·m/kg; IQR, 1.30-1.86 N·m/kg; P = .046). Patients between 5 and 6 months (66.4%; IQR, 54.2-78.6) had lower symmetry compared to patients between 6 and 7 months (71.8%; IQR,61.1-82.9; P = .019) and 8 and 9 months afterACLR (75.2%; IQR, 66.6-87.7; P = .014). Of the 40 patients that completed follow-up assessments, an increase in knee extensor torque of 0.22 N·m/kg and symmetry of 5.75% discriminated patients that achieved subjective improvement. A period of 1.97 months between assessments discriminated those that achieved the established symmetry threshold.

CONCLUSION

Patients demonstrate increasing subjective and quadriceps function when tested at later time points from surgery; however, the observed values are low, suggesting that at 9 months patients are demonstrating deficits that may be improving. Approximately 2 months is needed to observe clinically meaningful improvements.