Patient predictors of early revision surgery after anterior cruciate ligament reconstruction: a cohort study of 16,930 patients with 2-year follow-up

Validating the capture rate of revisions by the New Zealand ACL Registry: An analysis of all-cause reoperation following primary ACL reconstruction

PURPOSE

To validate the New Zealand Anterior Cruciate Ligament (ACL) Registry's capture rate of revisions by cross-referencing Registry data with reoperations data recorded by the Accident Compensation Corporation (ACC) and identify risk factors for all-cause reoperation.

METHODS

Primary ACL reconstructions performed between April 2014 and September 2019 were individually matched on a record-by-record basis between the two databases. The ACC database was used to identify patients who underwent a reoperation with manual review of operation notes to identify whether a revision or other procedure was performed. This was combined with the number of revisions separately recorded in the New Zealand ACL Registry, which was used as the denominator value to calculate the Registry's capture rate of revisions. Patient and surgical data recorded in the Registry were analysed to identify independent predictors for all-cause reoperation.

RESULTS

A total of 8046 primary ACL reconstructions were matched between the New Zealand ACL Registry and the ACC databases. The reoperation rate was 8.9% (n = 715) at a mean follow-up of 2.5 years. Meniscal-related procedures were the most common reoperation (n = 299, 3.7%), followed by revision ACL reconstruction (n = 219, 2.7%), arthrofibrosis (n = 185, 2.3%), cartilage (n = 56, 0.7%) and implants (n = 32, 0.4%). The New Zealand ACL Registry captured 96% of revisions. Younger age (hazard ratio [HR] > 1.4, p < 0.001), earlier surgery (HR > 1.3, p = 0.05), concurrent meniscal repair (medial meniscus HR = 1.9, p < 0.001 and lateral meniscus HR = 1.3, p = 0.022) and hamstring tendon autografts (HR = 1.4, p = 0.001) were associated with a higher risk of reoperation.

CONCLUSION

The New Zealand ACL Registry captured 96% of revisions. Risk factors for all-cause reoperation included younger age, earlier surgery, meniscal repair and hamstring tendon autografts.

LEVEL OF EVIDENCE

Level III.

Unraveling sex-specific risks of knee osteoarthritis before menopause: Do sex differences start early in life?

OBJECTIVE

Sufficient evidence within the past two decades have shown that osteoarthritis (OA) has a sex-specific component. However, efforts to reveal the biological causes of this disparity have emerged more gradually. In this narrative review, we discuss anatomical differences within the knee, incidence of injuries in youth sports, and metabolic factors that present early in life (childhood and early adulthood) that can contribute to a higher risk of OA in females.

DESIGN

We compiled clinical data from multiple tissues within the knee joint-since OA is a whole joint disorder-aiming to reveal relevant factors behind the sex differences from different perspectives.

RESULTS

The data gathered in this review indicate that sex differences in articular cartilage, meniscus, and anterior cruciate ligament are detected as early as childhood and are not only explained by sex hormones. Aiming to unveil the biological causes of the uneven sex-specific risks for knee OA, we review the current knowledge of sex differences mostly in young, but also including old populations, from the perspective of (i) human anatomy in both healthy and pathological conditions, (ii) physical activity and response to injury, and (iii) metabolic signatures.

CONCLUSIONS

We propose that to close the gap in health disparities, and specifically regarding OA, we should address sex-specific anatomic, biologic, and metabolic factors at early stages in life, as a way to prevent the higher severity and incidence of OA in women later in life.

Difference of Knee Strength Recovery Between Revision and Primary ACL Reconstruction

Different grafting procedures are available to restore knee stability after revision anterior cruciate ligament (ACL) reconstruction. We compared knee strength recovery between ACL revision surgery and primary reconstruction. One hundred and ten patients with ACL revision surgery were matched with 110 patients with primary reconstruction based on the graft procedure. The isokinetic knee strength had been assessed for the first 9 months post-surgery. Knee laxity, function, and activity score were also evaluated. Limb symmetry index for knee extensor and flexor strength was not different at 4-, 6- and 9-months post-surgery between revision surgery and primary reconstruction. These results depended on ipsilateral or contralateral graft choice. Ipsilateral hamstring tendon (HT) and contralateral bone-patellar-tendon-bone (BPTB) graft procedures were similar for a revision of a BPTB graft failure. Contralateral HT procedure was better than ipsilateral BPTB procedure for a revision of a HT graft failure. The early recovery of isokinetic knee strength after ACL revision surgery regardless of the HT or BPTB procedures, was similar to the recovery after primary ACL reconstruction with the same graft technique. These results apparently depended on a temporary quadriceps arthrogenic muscle inhibition and on a persistent donor site morbidity, concerning the new and the previous grafts, respectively.

Comparison of Contralateral ACL Rupture Versus ACL Graft Rupture in Australian Netballers After ACL Reconstruction

Background

Netball is a popular sport worldwide, particularly for women. However, its nature puts players at high risk for anterior cruciate ligament (ACL) injury.

Purpose

To determine (1) the prevalence of ACL graft rupture and contralateral ACL (CACL) rupture in Australian female netballers after ACL reconstruction (ACLR) and (2) the rate of return to sports (RTS) and psychological readiness.

Study Design

Cohort study; Level of evidence, 3.

Methods

A patient database identified 332 consecutive female netball players who underwent ACLR with hamstring tendon autografts performed by 2 surgeons between 2007 and 2015. Patients were retrospectively surveyed at a minimum of 7 years postoperatively-including details of a second ACL injury to either knee, RTS, and psychological readiness per the ACL-Return to Sport After Injury (ACL-RSI) score. Multivariate regression assessed the association between selected variables and repeat ACL injury.

Results

A total of 267 patients (80%) were included with a mean follow-up of 8.4 years (range, 7-15 years). ACL graft rupture and CACL rupture occurred in 11 (4%) and 27 (10%) patients, respectively, at 7 years postoperatively. The ACL graft had a survival rate of 99%, 97%, 97%, and 96% at 1, 2, 5, and 7 years after surgery, respectively. The native CACL had a survival rate of 100%, 99%, 94%, and 90% at 1, 2, 5, and 7 years, respectively. Adolescents had a 4.5 times greater hazard for ACL graft rupture (95% CI, 1.4-14.6; P = .014) and a 2.5 times greater hazard for CACL rupture (95% CI, 1.2-5.5; P = .021) compared with adults. CACL injury was also associated with a return to level 1-including jumping, hard pivoting, and cutting-sports (hazard ratio, 10.3 [95% CI, 1.4-77.1]; P = .023). Most (62%) participants returned to netball, with those with higher ACL-RSI scores more likely to RTS.

Conclusion

The prevalence of repeat ACL injury was higher in the contralateral knee (10%) than the ACL-reconstructed knee (4%) at 7 years postoperatively. ACLR was a suitable option for female netballers who sustained an ACL rupture with low long-term rates of graft rupture. Repeat ACL injuries to either knee were more common in adolescents and those who returned to cutting and pivoting sports.

Unsupervised Machine Learning of the Combined Danish and Norwegian Knee Ligament Registers: Identification of 5 Distinct Patient Groups With Differing ACL Revision Rates

BACKGROUND

Most clinical machine learning applications use a supervised learning approach using labeled variables. In contrast, unsupervised learning enables pattern detection without a prespecified outcome.

PURPOSE/HYPOTHESIS

The purpose of this study was to apply unsupervised learning to the combined Danish and Norwegian knee ligament register (KLR) with the goal of detecting distinct subgroups. It was hypothesized that resulting groups would have differing rates of subsequent anterior cruciate ligament reconstruction (ACLR) revision.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

K-prototypes clustering was performed on the complete case KLR data. After performing the unsupervised learning analysis, the authors defined clinically relevant characteristics of each cluster using variable summaries, surgeons' domain knowledge, and Shapley Additive exPlanations analysis.

RESULTS

Five clusters were identified. Cluster 1 (revision rate, 9.9%) patients were young (mean age, 22 years; SD, 6 years), received hamstring tendon (HT) autograft (91%), and had lower baseline Knee injury and Osteoarthritis Outcome Score (KOOS) Sport and Recreation (Sports) scores (mean, 25.0; SD, 15.6). Cluster 2 (revision rate, 6.9%) patients received HT autograft (89%) and had higher baseline KOOS Sports scores (mean, 67.2; SD, 16.5). Cluster 3 (revision rate, 4.7%) patients received bone-patellar tendon-bone (BPTB) or quadriceps tendon (QT) autograft (94%) and had higher baseline KOOS Sports scores (mean, 65.8; SD, 16.4). Cluster 4 (revision rate, 4.1%) patients received BPTB or QT autograft (88%) and had low baseline KOOS Sports scores (mean, 20.5; SD, 14.0). Cluster 5 (revision rate, 3.1%) patients were older (mean age, 42 years; SD, 7 years), received HT autograft (89%), and had low baseline KOOS Sports scores (mean, 23.4; SD, 17.6).

CONCLUSION

Unsupervised learning identified 5 distinct KLR patient subgroups and each grouping was associated with a unique ACLR revision rate. Patients can be approximately classified into 1 of the 5 clusters based on only 3 variables: age, graft choice (HT, BPTB, or QT autograft), and preoperative KOOS Sports subscale score. If externally validated, the resulting groupings may enable quick risk stratification for future patients undergoing ACLR in the clinical setting. Patients in cluster 1 are considered high risk (9.9%), cluster 2 patients medium risk (6.9%), and patients in clusters 3 to 5 low risk (3.1%-4.7%) for revision ACLR.

A lateral extra-articular tenodesis without additional hardware: Surgical technique and biomechanical comparison with an anatomic anterolateral ligament reconstruction in the augmentation of anterior cruciate ligament reconstruction

BACKGROUND

The aims of this study were to describe a lateral extra-articular tenodesis (LET) using no additional hardware and compare the tibiofemoral kinematics of anterior cruciate ligament (ACL) reconstruction augmented with either the LET or a standard anatomic anterolateral ligament (ALL) reconstruction using intra-tunnel fixation.

METHODS

Ten cadaveric knees were mounted on a robotic testing system and underwent a kinematic assessment of anterior tibial translation and internal tibial rotation under a simulated pivot-shift in the following states: ACL-intact, ACL-sectioned, ACL-sectioned/anterolateral complex (ALC)-sectioned, ACL-reconstructed/ALC-sectioned, ACL-reconstructed/ALL-reconstructed, and ACL-reconstructed/LET. For the LET, an iliotibial autograft was passed under the fibular collateral ligament and secured to the femur with the pull sutures of the ACL reconstruction femoral cortical suspensory fixation device, positioned at the distal ridge of Kaplan's fibers.

RESULTS

Anterior tibial translation was restored to normal by ACL reconstruction without meaningful benefit of augmentation with LET or ALL. ACL reconstruction restored internal tibial rotation close to normal between 0° and 30°, but increased internal tibial rotation persisted between 45° and 90°. Augmentation of ACL reconstruction with the LET reduced internal rotation close to normal between 45° and 90°, whereas increased internal rotation persisted after ALL reconstruction.

CONCLUSION

ACL reconstruction and LET are complementary in controlling tibiofemoral kinematics of knees with a combined ACL and ALC injury: ACL reconstruction restored native tibiofemoral kinematics except for internal rotation at flexion greater than 30°. The increased internal rotation at flexion greater than 30° was restored to normal with an LET, but not with an ALL reconstruction.

Relationship of Knee Abduction Moment to Trunk and Lower Extremity Segment Acceleration during Sport-Specific Movements

The knee abduction moment (KAM) has been identified as a significant predictor of anterior cruciate ligament (ACL) injury risk; however, the cost and time demands associated with collecting three-dimensional (3D) kinetic data have prompted the need for alternative solutions. Wearable inertial measurement units (IMUs) have been explored as a potential solution for quantitative on-field assessment of injury risk. Most previous work has focused on angular velocity data, which are highly susceptible to bias and noise relative to acceleration data. The purpose of this pilot study was to assess the relationship between KAM and body segment acceleration during sport-specific movements. Three functional tasks were selected to analyze peak KAM using optical motion capture and force plates as well as peak triaxial segment accelerations using IMUs. Moderate correlations with peak KAM were observed for peak shank acceleration during single-leg hop; peak trunk, thigh, and shank accelerations during a deceleration task; and peak trunk, pelvis, and shank accelerations during a 45° cut. These findings provide preliminary support for the use of wearable IMUs to identify peak KAM during athletic tasks.

The healing effect of the all inside technique is superior to the traditional technique in the reconstruction of the anterior cruciate ligament

Our main objective was to examine the curative effect of all inside technique and traditional technique in anterior cruciate ligament (ACL) reconstruction. In our retrospective study at the First People's Hospital of Jiashan County, we analyzed 88 participants with ACL injuries (50 males, 38 females, average age 27 years). They were randomly divided into two groups: traditional ACL reconstruction (42 participants) and all inside ACL reconstruction (46 participants). We measured and recorded the Visual Analog Scores (VAS), International Knee Documentation Committee (IKDC), Lysholm scores, operation time, graft diameter and length between the traditional technique group and all inside technique group. There were statistically significant differences in the Lysholm scores and IKDC scores between traditional and all inside technique groups. The all inside technique showed a higher efficacy and effective post-operative recovery with minimal pain and recurrent injuries. Our findings showed that the differences in gender, age, side of injury and operation time were not significant (p> 0.05). Follow-up was conducted at 6 months and 12 months post operations (mean, 7.5 ± 1.1 months). All inside technique minimizing tissue disruption, optimizing graft placement and facilitating early recovery have a significant impact on patient outcomes.

Estimation Failure Risk by 0.5-mm Differences in Autologous Hamstring Graft Diameter in Anterior Cruciate Ligament Reconstruction: A Meta-analysis

BACKGROUND

Because grafts are made in 0.5-mm increments clinically for anterior cruciate ligament (ACL) reconstruction, it is important to clarify how the failure rate decreases as the diameter increases. Moreover, it is important to know whether even a slight increase in the graft diameter decreases the risk of failure.

HYPOTHESIS

The risk of failure decreases significantly with each 0.5-mm increase in hamstring graft diameter.

STUDY DESIGN

Meta-analysis; Level of evidence, 4.

METHODS

The systematic review and meta-analysis have estimated the diameter-specific failure risk for each 0.5-mm increase in ACL reconstruction using autologous hamstring grafts. We searched for studies describing the relationship between graft diameter and failure rate published before December 1, 2021, in leading databases, such as PubMed, EMBASE, Cochrane Library, and Web of Science, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We included studies using single-bundle autologous hamstring grafts to investigate the relationship between failure rate and graft diameter of 0.5-mm intervals with >1-year follow-up. Then, we calculated the failure risk caused by 0.5-mm differences in autologous hamstring graft diameter. Assuming Poisson distribution for the statistical model, we employed an extended linear mixed-effects model in the meta-analyses.

RESULTS

Five studies containing 19,333 cases were eligible. The meta-analysis revealed that the estimated value of the coefficient of diameter in the Poisson model was -0.2357 with a 95% CI of -0.2743 to -0.1971 (P < .0001). With every 1.0-mm increase in diameter, the failure rate decreased by 0.79 (0.76-0.82) times. In contrast, the failure rate increased by 1.27 (1.22-1.32) times for each 1.0-mm decrease in diameter. The failure rate significantly decreased with each 0.5-mm increase in graft diameter in the range of <7.0 to >9.0 mm from 3.63% to 1.79%.

CONCLUSION

The risk of failure decreased correspondingly with each 0.5-mm increase in graft diameter in the range of <7.0 to >9.0 mm. Failure is multifactorial; however, increasing the graft diameter as much as possible to match each patient's anatomic space without overstuffing is an effective precaution that surgeons can take to reduce failures.

Improved Patient-reported Outcomes in Patients Aged 16 and Younger at Two Years After Anterior Cruciate Ligament Reconstruction Despite Relatively High Rates of Reinjury and Repeat Surgery

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) in adolescent patients, particularly those aged 16 and under, are increasingly common procedure that lacks robust clinical and patient-reported outcome (PRO) data. The purpose of this study was to report 2-year PROs of patients receiving ACLR aged 16 or younger using the single assessment numerical evaluation (SANE) and knee injury and osteoarthritis outcome score (KOOS). Secondary aims included characterizing treatment characteristics, return to sport (RTS), and clinical outcomes.

METHODS

The institutional PRO database was queried for patients receiving ACLR from 2009 to 2020. Patients aged older than 16, revision procedures, concomitant ligament repairs/reconstructions, and patients without full outcome data at 2 years were excluded. Outcomes over 2 years after ACLR included SANE, KOOS, reinjuries, reoperations, and time to RTS.

RESULTS

A total of 98 patients were included with an average age of 15.0 years. Most patients were females (77.6%). Bone-tendon-bone autograft (69.4%) was the most used. Average RTS was 8.7 months (range: 4.8 to 24.0 mo), with 90% of patients eventually returning to sport. A total of 23 patients (23.5%) experienced a reinjury and 24.5% (n = 24) underwent reoperation. Timing to RTS was not associated with reinjury, but patients who returned between 9.5 and 13.7 months did not sustain reinjuries. Mean KOOS and SANE scores at 2 years were 87.1 and 89.1, respectively, with an average improvement of +18.4 and +22.9, respectively. Change in KOOS was negatively impacted by reinjury to the anterior cruciate ligament graft and reoperation (anterior cruciate ligament failure: +10.0 vs 19.3, P = 0.081, respectively; reoperation: +13.2 vs +20.1, P = 0.051, respectively), though these did not reach statistical significance.

CONCLUSION

Patients experienced improved SANE and KOOS scores after ACLR. Rates of reinjury and reoperation were relatively high and negatively impacted PRO scores but were not associated with the timing of RTS. Adolescent patients should be counseled regarding the risk of subsequent ipsilateral and contralateral knee injury after ACLR.

LEVEL OF EVIDENCE

Level IV-case series.

Enthesis maturation in engineered ligaments is differentially driven by loads that mimic slow growth elongation and rapid cyclic muscle movement

Entheses are complex attachments that translate load between elastic-ligaments and stiff-bone via organizational and compositional gradients. Neither natural healing, repair, nor engineered replacements restore these gradients, contributing to high re-tear rates. Previously, we developed a culture system which guides ligament fibroblasts in high-density collagen gels to develop early postnatal-like entheses, however further maturation is needed. Mechanical cues, including slow growth elongation and cyclic muscle activity, are critical to enthesis development in vivo but these cues have not been widely explored in engineered entheses and their individual contribution to maturation is largely unknown. Our objective here was to investigate how slow stretch, mimicking ACL growth rates, and intermittent cyclic loading, mimicking muscle activity, individually drive enthesis maturation in our system so to shed light on the cues governing enthesis development, while further developing our tissue engineered replacements. Interestingly, we found these loads differentially drive organizational maturation, with slow stretch driving improvements in the interface/enthesis region, and cyclic load improving the ligament region. However, despite differentially affecting organization, both loads produced improvements to interface mechanics and zonal composition. This study provides insight into how mechanical cues differentially affect enthesis development, while producing some of the most organized engineered enthesis to date. STATEMENT OF SIGNIFICANCE: Entheses attach ligaments to bone and are critical to load transfer; however, entheses do not regenerate with repair or replacement, contributing to high re-tear rates. Mechanical cues are critical to enthesis development in vivo but their individual contribution to maturation is largely unknown and they have not been widely explored in engineered replacements. Here, using a novel culture system, we provide new insight into how slow stretch, mimicking ACL growth rates, and intermittent cyclic loading, mimicking muscle activity, differentially affect enthesis maturation in engineered ligament-to-bone tissues, ultimately producing some of the most organized entheses to date. This system is a promising platform to explore cues regulating enthesis formation so to produce functional engineered replacements and better drive regeneration following repair.

Functional Rehabilitation of Anterior Cruciate Ligament Tear in the Pediatric Population: A Comprehensive Review

Pediatric sports injuries are a growing concern due to increased youth participation in sports. Effective rehabilitation strategies are essential for ensuring optimal recovery, restoring knee function, and preventing long-term consequences. This research aims to explore and evaluate various functional rehabilitation approaches tailored to pediatric anterior cruciate ligament (ACL) tear injuries. Functional rehabilitation of ACL tears in pediatric sports injuries is an important area of research due to the unique considerations and challenges that arise when treating ACL injuries in young athletes. Over the last 20 years, there has been a well-documented uptick in ACL injuries among pediatric populations. This rise can be attributed to the growing involvement of the younger population in competitive sports, as well as heightened awareness regarding sports-linked injuries. This study highlights the importance of early surgical reconstruction in children to enable a quick return to sports and prevent long-term cartilage and meniscal damage resulting from instability. The use of physeal-sparing ACL reconstruction techniques, particularly hamstring autografts, is recommended for favorable clinical outcomes while minimizing growth disturbances. This study offers valuable insights for healthcare professionals and researchers, serving as a reference to guide optimal approaches in managing pediatric ACL injuries and achieving successful results in this field.

Differences in the microstructural and mechanical qualities of semitendinosus tendon grafts between skeletally immature and mature patients in anterior cruciate ligament reconstruction

BACKGROUND

This study aimed to investigate the microstructural and mechanical properties of semitendinosus tendon graft tissues during anterior cruciate ligament reconstruction and the clinical outcomes in skeletally immature and mature patients.

METHODS

Twenty-two patients who underwent primary anterior cruciate ligament reconstruction using a hamstring tendon graft were analyzed and divided into skeletally immature (n = 7) and mature groups (n = 15) based on magnetic resonance imaging findings of the epiphyseal plate of the distal femur. Tissue samples were collected from the mid-portion of the semitendinosus tendon. The collagen fibril diameter, maximum stress, and strain at maximum stress point in the semitendinosus tendon tissues were calculated for comparison of the microstructural and mechanical properties between the two groups. Postoperative outcomes were also assessed between the two groups.

RESULTS

The mean and 60th and 80th percentiles of fibril diameters in the skeletally immature group were significantly smaller than those in the mature group (65.9 ± 13.0, 73.5 ± 19.3, and 91.3 ± 27.4 nm in the skeletally immature group; and 90.3 ± 14.7, 94.0 ± 18.4, and 125.3 ± 19.9 nm in the skeletally immature group; p = 0.001, 0.024, and 0.004, respectively). Additionally, the strain at maximum stress was higher in the skeletally immature group (237.2 ± 102.4% vs. 121.5 ± 51.9%, p = 0.024). However, there was no difference in maximum stress between the skeletally immature and mature groups (19.9 ± 14.3 MPa vs. 24.5 ± 23.4 MPa, p = 0.578). Strain was negatively correlated with the mean fibril diameter and the 60th and 80th percentiles of fibril diameters, whereas stress was positively correlated with the mean fibril diameter. The skeletally immature group had a higher pivot shift test-positive rate than the mature group at the last follow-up (p = 0.023).

CONCLUSION

Semitendinosus tendon graft tissues differed microstructurally and mechanically between skeletally immature and mature patients.

LEVEL OF EVIDENCE

Level Ⅳ.

Clinical and Patient-Reported Functional Outcome of Semitendinosus Autograft Anterior Cruciate Ligament Reconstruction With FiberTape® InternalBrace™ All-Inside Technique: A Prospective Study

AIM

The purpose of this study is to report the early one-year clinical and patient-reported functional outcomes of semitendinosus autograft anterior cruciate ligament reconstruction with the FiberTape® InternalBrace™ all-inside technique.

MATERIALS AND METHODS

The patient-reported functional outcomes and clinical outcomes were analyzed prospectively following the treatment of 324 unilateral ACL rupture cases with the FiberTape® InternalBrace™ Technique. Patient-reported outcome measures (KOOS scores, WOMAC scores, VAS score, and IKDC score) and clinical examinations like pre-operative and post-operative pivot shift, Lachman test, and range of motion (ROM) were conducted. These tests and examinations were recorded for each patient before surgery and at 3, 6, and 12 months after surgery. Secondary outcomes like re-rupture, infection, synovitis, or limited range of motion were noted. The mean follow-up period was 18±4.5 months (range: 12-24 months).

RESULTS

Out of a total of 324 cases, 37 cases (11.4%) could not be followed up. 158 patients (55.1%) were male and 129 were female (44.9%). Preoperative mean KOOS pain value, KOOS symptoms, KOOS ADLs, KOOS sport and recreation, and KOOS quality of life were 77.05, 78.69, 84, 21, 89.7, and 57, respectively. All KOOS subsections increased significantly at one-year to 98.37, 99.09, 98.95, 99.02, and 99.30 (p<0.0001), respectively. Mean preoperative WOMAC pain, WOMAC stiffness, and WOMAC function were 76.4, 65.2, and 74.1 and increased significantly at one-year to 94.5, 89.6, and 98.2 (p<0.0001), respectively. There was a significant decrease in VAS for pain from 2.93 before surgery to 0.12 (p<0.0001) at one year. The IKDC score significantly changed from a pre-treatment value of 50.9 to 96.2 (94.5-97.8) at a follow-up of one year. The Lysholm score at 12-months was significant at 95 (93.1-96.9), p<0.05. Post-operative Lachman test values decreased significantly, which meant decreased laxity, from 1.98 (1.89-2.07) pre-operative to 1.60 (1.57-1.62) p<0.05 at one-year post-operative. At one-year follow-up, 276 patients (96%) had fully recovered.

CONCLUSION

It was concluded that the FiberTape® InternalBrace™ technique for ACL reconstruction provides orthopedic surgeons with an effective alternative technique to conventional methods of surgery and also reduces the overall time to recovery for patients, thereby allowing them to return to sports faster.

LEVEL OF EVIDENCE

Level 4.

Association of Tibial Tubercle-Trochlear Groove Distance With Risk of ACL Graft Failure

Background

Limited evidence suggests a positive correlation between tibial tubercle-trochlear groove (TT-TG) distance and the risk of native anterior cruciate ligament (ACL) tear. The relationship between TT-TG distance and the risk of ACL graft failure is unknown.

Hypothesis

TT-TG distance is independently associated with risk of ACL graft failure.

Study Design

Cohort study; Level of evidence, 3.

Methods

All patients who underwent ACL revision surgery between 2010 and 2018 at a single institution were identified. A control cohort underwent primary ACL reconstruction (ACLR) between 2006 and 2015, with no evidence of graft failure at 8.1 ± 2.5 years postoperatively. Record review included anthropometrics, graft type, and estimated Tegner activity score at ≥6 months after primary ACLR. Magnetic resonance imaging (MRI) scans after native ACL tear (controls) or graft failure (revision cohort) were assessed for (1) TT-TG distance, (2) proximal tibial slopes, (3) depth of tibial plateau concavity, and (4) tunnel position (revision cohort). Associations between ACL graft failure and MRI measurements, surgical variables, and patient characteristics were evaluated with logistic regression analyses. Sensitivity analyses, excluding patients with tunnel malposition, were performed to confirm multivariable results in patients with "ideal" tunnel placement.

Results

Participants included 153 patients who underwent revisions and 144 controls. Controls were older than the patients who underwent revision (26.6 ± 8.8 vs 20.6 ± 7.3 years; P < .001). The mean TT-TG distance and lateral posterior tibial slope (PTS) were smaller for the control group than for the revision group (TT-TG: 9.3 ± 3.9 vs 11.2 ± 4.2 mm; P < .001; lateral PTS: 6.2° ± 3.3° vs 7.2° ± 3.6°; P = .01). TT-TG distance, lateral PTS, and age were associated with risk of ACL graft failure by multivariable analysis (OR, 1.15; 95% CI, 1.07-1.23; P < .001; OR, 1.13; 95% CI, 1.04-1.22; P = .004; and OR, 0.90; 95% CI, 0.87-0.94; P < .001, respectively). With sensitivity analyses, TT-TG distance, lateral PTS, and age at index surgery remained significantly and independently associated with ACL graft failure.

Conclusion

Increased TT-TG distance, increased lateral PTS, and younger age are independently associated with increased odds of ACL graft failure. Patients with these characteristics may require a more comprehensive strategy to reduce the risk of ACL reinjury.

Comparative study of the clinical efficacy of all-inside and traditional techniques in anterior cruciate ligament reconstruction

BACKGROUND

Many studies have focused on the femoral tunnel technique and fixation method, but few studies have involved the tibial tunnel technique and fixation method. The all-inside technique is one of the new techniques that has been described in recent years. All-inside anterior cruciate ligament (ACL) reconstruction is based on a tibial socket instead of a full tunnel. This method has many potential advantages.

AIM

To compare clinical outcomes of knee ACL autograft reconstruction using all-inside quadrupled semitendinosus (AIST) and traditional hamstring tendon (TBT) techniques.

METHODS

From January 2017 to October 2019, the clinical data of 80 patients with ACL reconstruction were retrospectively analyzed, including 67 males and 13 females. The patients had an average age of 24.3 ± 3.1 years (age range: 18-33 years). The AIST technique was used in 42 patients and the TBT technique was used in 38 patients. The time between operation and injury, operative duration, postoperative visual analogue scale (VAS) score and knee functional recovery were recorded and compared between the two groups. The International Knee Documentation Committee (IKDC) and Lysholm scoring system were used to comprehensively evaluate clinical efficacy.

RESULTS

Eighty patients were followed for 24-36 mo, with an average follow-up duration of 27.5 ± 1.8 mo. There were no significant differences in the time between surgery and injury, operative duration, IKDC and Lysholm scores of the affected knee at the last follow-up evaluation between the two groups. There were significant differences in VAS scores 1 d, 3 d, 7 d, 2 wk and 1 mo after surgery (P < 0.05). There was no significant difference in VAS score at 3 mo, 6 mo and 1 year after operation.

CONCLUSION

The efficacy of the AIST ACL reconstruction technique was comparable to the TBT technique, but the postoperative pain was less with the AIST technique. Thus, the AIST technique is an ideal treatment choice for ACL reconstruction.

Effect of Cross-sectional Area of the Hamstring Tendon Autograft on Failure Rate or Clinical Outcomes After Double-Bundle ACL Reconstruction: Tendon Autograft

Background

In previous studies examining the relationship between graft size and failure rate after anterior cruciate ligament reconstruction (ACLR), graft size was determined as diameter of the bone tunnel, and graft failure was defined as revision surgery. Consequently, the correlation between graft size and postoperative recurrent instability could not be assessed.

Purpose

(1) To intraoperatively measure the cross-sectional area (CSA) of the hamstring tendon (HT) autograft and compare the CSA of the autograft with the bone tunnel and (2) to assess the effect of the graft CSA on postoperative graft failure among patients who underwent double-bundle ACLR.

Study Design

Case-control study; Level of evidence, 3.

Methods

The study included 129 patients who underwent double-bundle ACLR using an HT autograft (mean ± SD age, 16.7 ± 1.7 years; all with a Tegner activity level ≥6). All patients had a minimum follow-up of 2 years. During surgery, the graft CSA was measured using an area micrometer, combining the anteromedial (AM) and posterolateral (PL) grafts. The total area of the bone tunnel was defined as the combined CSAs of the AM and PL tunnels as calculated by the diameter of the drill. The relationship between the CSAs of the combined HT graft and the bone tunnel was statistically compared, as was the relationship between graft CSAs and graft failure, defined as reinjury, recurrent instability manifested as quantitative laxity measurement, or revision ACLR.

Results

The CSAs of the midsubstance of the combined AM and PL graft significantly correlated with those of the bone tunnels (femoral side, R ² = 0.334, P < .0001; tibial side, R ² = 0.421, P < .0001). As for the relationship between the graft CSA and ACLR failure, there was no significant difference in the graft CSAs between the groups with and without graft failure in any of the failure criteria (P = .188).

Conclusion

The graft CSA was not a predictor of early failure after double-bundle ACLR using an HT autograft in this patient population.

Return to Sports: A Risky Business? A Systematic Review with Meta-Analysis of Risk Factors for Graft Rupture Following ACL Reconstruction

BACKGROUND

The risk of sustaining a graft rupture after anterior cruciate ligament reconstruction (ACLR) is high. Contributing risk factors are, however, still not clearly identified.

OBJECTIVE

The aim of this systematic review was to identify and quantify risk factors for graft rupture after ACLR.

METHODS

A systematic review with meta-analysis (PROSPERO CRD42020140129) based on PRISMA guidelines was performed. MEDLINE, CINAHL and EMBASE were searched from inception to September 2021. Prospective and retrospective studies addressing risk factors for graft rupture after ACLR in males/females of all ages were considered. Meta-analyses using a random effect model (effect measure: odds ratio [OR] with 95% confidence interval [CI]) were performed. The GRADE tool was used to assess evidence quality.

RESULTS

Following full-text screening of 310 relevant papers, 117 were eventually included, incorporating up to 133,000 individuals in each meta-analysis. Higher Tegner activity level (≥ 7 vs < 7) at primary injury (OR 3.91, 95% CI 1.69-9.04), increased tibial slope (degrees) (OR 2.21, 95% CI 1.26-3.86), lower psychological readiness to return to sport (RTS) (OR 2.18, 95% CI 1.32-3.61), early surgery (< 12 vs ≥ 12 months) (OR 1.87, 95% CI 1.58-2.22), RTS (pre-injury level) (OR 1.87, 95% CI 1.21-2.91) and family history of ACL injury (OR 1.76, 95% CI 1.34-2.31) were all associated with increased odds of graft rupture. Higher age (OR 0.47, 95% CI 0.39-0.59), female sex (OR 0.88, 95% CI 0.79-0.98), fewer self-reported knee symptoms pre-reconstruction (OR 0.81, 95% CI 0.69-0.95) and concomitant cartilage injuries (OR 0.70, 95% CI 0.62-0.79) instead decreased the odds. Meta-analysis revealed no association between body mass index, smoking, joint laxity, RTS time, knee kinematics, muscle strength or hop performance and graft rupture.

CONCLUSION

Conspicuous risk factors for graft rupture were mainly sports and hereditary related. Few studies investigated function-related modifiable factors or included sports exposure data.

Early outcomes of primary repair versus reconstruction for acute anterior cruciate ligament injury: A systematic review and meta-analysis

BACKGROUND

Contemporary techniques for repair of acute anterior cruciate ligament (ACL) rupture have been receiving renewed interest recently because of reports of good outcomes.

METHODS

A literature search of PUBMED, MEDLINE, EMBASE, and the Cochrane Library was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Only RCTs published in English and comparing clinical outcomes of ACL repair versus reconstruction were included. Outcomes were evaluated using the International Knee Documentation Committee subjective score, Lysholm score, Tegner activity scale, visual analog scale pain score, anterior laxity, Lachman test, hop tests, knee injury and osteoarthritis outcome score, extension deficit, revision rate, and re-rupture rate. Statistical analysis was performed with Review Manager 5.4 and Stata 14.0. Two-tailed P < .05 was considered statistically significant.

RESULTS

Four RCTs (with a total of 293 patients) that met the eligibility criteria were included in this review. Over short-term follow-up, none of the studies found significant differences between the repair groups and reconstruction groups with respect to International Knee Documentation Committee, Lysholm, Tegner, visual analog scale, anterior laxity, Lachman test, re-rupture rate, extension deficit, and performance of 3 hop tests (P > .05). In both groups, the hop tests scores were >90%.

CONCLUSION

ACL repair and ACL reconstruction appear to provide comparable short-term outcomes. The low revision rate after primary repair is encouraging. For patients with ACL injury, current repair techniques such as dynamic intraligamentary stabilization and bridge-enhanced ACL repair may be an effective alternative to reconstruction.

Combined Anterior Cruciate Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis Better Restores Knee Stability and Reduces Failure Rates Than Isolated Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients

BACKGROUND

The increase in anterior cruciate ligament (ACL) injuries in pediatric patients and the high failure rate reported in the literature in this population are driving surgeons to search for specific techniques to better restore knee stability. Recent literature has reported that the combination of lateral extra-articular tenodesis (LET) and ACL reconstruction improves outcomes in high-risk patients. However, such advantages in pediatric patients have been infrequently evaluated.

PURPOSE

To assess whether adding LET to ACL reconstruction can significantly improve knee stability, clinical outcomes, and failure rates in pediatric patients.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A multicentric study involving 3 orthopaedic teaching centers was conducted to evaluate pediatric patients aged between 12 and 16 years who had undergone primary ACL reconstruction using a physeal-sparing femoral tunnel drilling technique. A minimum 2-year follow-up evaluation was required. Based on the surgical technique performed, the patients were divided into 2 group. The patients in group 1 underwent an isolated arthroscopic ACL reconstruction, while the patients in group 2 had an arthroscopic ACL reconstruction in combination with a modified Lemaire LET procedure. Group 1 was a historical control cohort of patients, whereas group 2 was prospectively enrolled. All the patients included in the present study were clinically evaluated using the Pediatric International Knee Documentation Committee (Pedi-IKDC) subjective score and the Pediatric Functional Activity Brief Scale (Pedi-FABS) score. Anteroposterior knee stability was measured using the KT-1000 knee ligament arthrometer, and the objective pivot-shift evaluation was documented using a triaxial accelerometer (Kinematic Rapid Assessment [KiRA]). The included patients also underwent a standardized radiological protocol to evaluate leg-length discrepancies, axial deviation, and degenerative signs preoperatively and at last follow-up.

RESULTS

This study included 66 pediatric patients with an anatomic hybrid ACL reconstruction using an autologous 4-strand hamstring graft. In group 1, there were 34 patients (mean age, 13.5 ± 1.2 years), while 32 patients (mean age, 13.8 ± 1.4 years) were included in group 2. The clinical outcome scores showed no difference between the 2 groups (Pedi-IKDC, P = .072; Pedi-FABS, P = .180). Nevertheless, the patients in group 2 had better anteroposterior stability measured using a KT-1000 arthrometer (1.9 ± 1.1 mm in group 1 vs 0.8 ± 0.8 mm in group 2; P = .031), as well as better rotational stability measured using the KiRA (-0.59 ± 1.05 m/s² in group 2 vs 0.98 ± 1.12 m/s² in group 1; P = .012). The patients in group 1 returned to sports at the same competitive level at a rate of 82.4%, while patients included in group 2 returned at the same competitive level in 90.6% of the cases without a significant difference between the 2 groups (P = .059). No leg-length discrepancies were found between the 2 groups at last follow-up (P = .881). Two patients displayed an increased valgus deformity of 3° on the operated limb at last follow-up (1 patient in group 1 and 1 patient in group 2). Group 1 had a significatively higher cumulative failure rate (14.7% vs 6.3%; P = .021). No intra- or postoperative complications was observed between the 2 groups.

CONCLUSION

Performing a modified Lemaire LET along with an ACL reconstruction with hamstring graft in pediatric patients reduced the cumulative failure rate and improved objective stability with no increase in intra- or postoperative complications. No significant difference was found between the 2 groups in terms of patient-reported outcomes or in the return-to-sports activity.

Combining Anterior Cruciate Ligament Reconstruction With Lateral Extra-Articular Procedures in Skeletally Immature Patients Is Safe and Associated With a Low Failure Rate

Purpose

To analyze the rates of graft ruptures and growth disorders, the level of return to sport, and the clinical results of 2 lateral extra-articular procedures in growing children.

Methods

This study was a retrospective, single-center study of patients undergoing anterior cruciate ligament (ACL) surgery combined with 2 different lateral extra-articular procedures (anatomic reconstruction with a gracilis graft or modified Lemaire technique with a strip of fascia lata). The measurements of side-to-side anterior laxity and pivot shift were performed preoperatively and at the last follow-up. The sports level and the complications rate were assessed. The minimal clinically important differences (MCID) and patient acceptable symptoms state threshold scores were calculated.

Results

Thirty-nine patients (40 ACLs) were included (20 anatomic and 20 modified Lemaire) at an average follow-up of 57 months ± 10 [42-74]. One patient (2.5%) was lost to follow-up. The mean age at surgery was 13.8 ± 1.4 years old [9.8; 16.5]. One graft failure was reported (2.6% [0.06-13.5]) at 35.6 months after surgery. Two cases (5.4%) of femoral overgrowth were observed, and one of them required distal femoral epiphysiodesis. Ninety-two percent of the patients returned to sports. At the final follow-up, side-to-side anterior laxity was significantly improved, and no residual pivot shift was recorded in 95% of patients. Eighty-nine percent of the patients presented a Pedi-International Knee Documentation Committee score greater than the MCID postoperatively, and 77% presented a Lysholm score greater than the MCID.

Conclusions

This series of ACL reconstructions combined with 2 different lateral extra-articular procedures in skeletally immature patients demonstrated promising findings. The low rate of observed complications, including graft rupture and growth disturbance, is encouraging, but the small study population and lack of comparative group precludes reliable conclusions.

Level of Evidence

IV, therapeutic case series.

Combined ACL and ALL reconstruction reduces the rate of reoperation for graft failure or secondary meniscal lesions in young athletes

PURPOSE

Graft failure and secondary meniscal tears are major concerns after anterior cruciate ligament (ACL) reconstruction in young athletes. The aim was to evaluate the link between ACL reconstruction with and without anterolateral ligament (ALL) reconstruction and outcomes in young patients participating in pivoting sports.

METHODS

This was a retrospective study of data collected prospectively. Patients less than 20 years, involved in pivoting sports and undergoing primary ACL reconstruction with a quadruple hamstring tendon (4HT) graft or 4HT graft combined with anterolateral ligament reconstruction (4HT + ALL) were included. Survival analysis was performed to identify the prognostic indicators for reoperation due to graft failure or secondary meniscal lesions. Knee laxity was assessed and patient reported outcome measures (PROMs) were collected.

RESULTS

A total of 203 patients (mean (± SD) age: 16.3 ± 2 years) with a mean follow-up of 4.8 ± 0.9 (range: 3.3‒6.8) years were included. There were 101 4HT and 102 4HT + ALL grafts. Graft rupture rates were 11.9% for 4HT grafts and 5.8% for 4HT + ALL grafts (n.s.). There were 9.9% secondary meniscal procedures for 4HT grafts vs. 1.9% for 4HT + ALL grafts (p = 0.02). With reoperation for graft failure or secondary meniscal lesions at final follow-up as the endpoint, survival was better in the 4HT + ALL group (91.4% vs. 77.8%, respectively; p = 0.03). Absence of ALL reconstruction (HR = 4.9 [95%CI: 1.4-17.9]; p = 0.01) and preoperative side-to-side laxity > 3 mm (HR = 3.1 [95%CI: 1.03-9.1]; p = 0.04) were independently associated with an increased rate of reoperations. Mean (± SD) side-to-side laxity was 1.3 ± 1.3 mm (range: - 2 to 5) for 4HT grafts vs. 0.9 ± 1.3 mm (range: - 6 to 4.8) for 4HT + ALL grafts (n.s.) 6 months post-surgery. The rate of return to the same sport at the same level was 42.2% for 4HT grafts vs. 52% for 4HT + ALL grafts (n.s.). There was no significant difference in subjective outcomes including PROMs between the two groups.

CONCLUSION

Combined ALL + ACL reconstruction reduced the rate of graft failure and secondary meniscal injury in young athletes when compared to ACL reconstruction alone. Subjective results were comparable, with a similar rate of complications. Combined reconstruction should be preferred in this young population.

LEVEL OF EVIDENCE

Level IV.

Comparable Instrumented Knee Joint Laxity and Patient-Reported Outcomes After ACL Repair With Dynamic Intraligamentary Stabilization or ACL Reconstruction: 5-Year Results of a Randomized Controlled Trial

BACKGROUND

Technical innovation has led to the renaissance of anterior cruciate ligament (ACL) repair in the past decade.

PURPOSE/HYPOTHESIS

The present study aimed to compare instrumented knee joint laxity and patient-reported outcomes (PROs) after ACL repair with those after primary ACL reconstruction for acute isolated ACL tears. It was hypothesized that ACL repair would lead to comparable knee joint stability and PROs at 5 years postoperatively in comparison with ACL reconstruction.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 85 patients with acute ACL tears were randomized to undergo either ACL repair using dynamic intraligamentary stabilization (DIS) or primary ACL reconstruction with a semitendinosus tendon autograft. The primary outcome was the side-to-side difference in anterior tibial translation (ΔATT) assessed by Rolimeter testing at 5 years postoperatively. Follow-up examinations were performed at 1, 2, and 5 years. PROs were assessed using the Tegner activity scale, the International Knee Documentation Committee (IKDC) subjective score, and the Lysholm score. Furthermore, the rates of recurrent instability, other complications, and revision surgery were recorded. A power analysis was performed a priori, and the Friedman test, Mann-Whitney U test, and Bonferroni correction were applied for statistical comparisons with significance set at P < .05.

RESULTS

The mean age at inclusion was 28.3 ± 11.5 years in the ACL repair group and 27.1 ± 11.5 years in the ACL reconstruction group. At 5 years postoperatively, a total of 64 patients (ACL repair: n = 34 of 43 [79%]; ACL reconstruction: n = 30 of 42 [71%]) were available for follow-up. At 5 years, ΔATT was 1.7 ± 1.6 mm in the ACL repair group and 1.4 ± 1.3 mm in the ACL reconstruction group (P = .334). Preinjury PROs were restored as soon as 1 year after surgery and plateaued until 2 and 5 years postoperatively in both groups. At the 5-year follow-up, the mean Lysholm score was 97.0 ± 5.4 versus 94.5 ± 5.5 (P = .322), respectively, and the mean IKDC subjective score was 94.1 ± 9.9 versus 89.9 ± 7.8 (P = .047), respectively, in the ACL repair group versus ACL reconstruction group. At 5 years postoperatively, 12 patients in the ACL repair group (35%; age <25 years: n = 10/12; Tegner score ≥7: n = 10/12) had recurrent instability, of whom 10 underwent single-stage revision ACL reconstruction. In the ACL reconstruction group, there were 6 patients with recurrent instability (20%; age <25 years: n = 6/6; Tegner score ≥7: n = 5/6); however, in 5 patients, staged revision was required. Differences between both groups regarding recurrent instability (P = .09) or ACL revision surgery (P = .118) were not statistically significant. Recurrent instability was associated with age <25 years and Tegner score >7 in both groups.

CONCLUSION

At 5 years after ACL repair with DIS, instrumented knee joint laxity and PROs were comparable with those after ACL reconstruction. Although no significant difference was found between repair and reconstruction, a critical appraisal of the rates of recurrent instability (35% vs 20%, respectively) and revision surgery (38% vs 27%, respectively) is needed. Young age and a high preinjury activity level were the main risk factors for recurrent instability in both groups. However, single-stage revision ACL reconstruction was possible in each case in the ACL repair group. Although ACL reconstruction remains the gold standard in the treatment of ACL tears, the present study supports the use of ACL repair with DIS as a feasible option to treat acute ACL tears in patients aged ≥25 years with low to moderate activity levels (Tegner score <7).

REGISTRATION

DRKS00015466 (German Clinical Trials Register).

A Squeaking Knee Is a Rare Complication of ACL Surgery: A Case Report

CASE

We report a rare case of a 36-year-old woman who underwent anterior cruciate ligament surgery (ACL), which was complicated by a squeaking knee postoperatively. The squeaking noise was likely due to migrating nonabsorbable suture engaging with the articular surface and created significant psychological stress but had no impact on the functional outcome of the patient. We eliminated the noise with an arthroscopic debridement of the suture that had migrated from the tibial tunnel.

CONCLUSION

A squeaking knee after ACL surgery due to migrating suture is a rare complication that, in this case, improved with surgical debridement and diagnostic imaging seems to have a limited role.

Increased posterior tibial slope is an independent risk factor of anterior cruciate ligament reconstruction graft rupture irrespective of graft choice

INTRODUCTION

Anterior cruciate ligament (ACL) reconstruction failure remains a commonly seen complication despite advances in technique and graft options. Recently, several studies have shown that the inclination of the tibial plateau in the sagittal plane affects the stability of the knee joint. The purpose of this study was to determine if an increased posterior slope of the tibia is associated with failure of ACL reconstruction irrespective of the graft used.

METHODS

From June 2002 to August 2003, a total of 100 patients with a symptomatic ACL-deficient knee were randomised to receive either a hamstring autograft or posterior tibialis allograft. All allografts were from a single tissue bank, aseptically processed, and fresh-frozen without terminal irradiation. ACL graft failures requiring reoperation with a minimum of 10-year follow-up were identified via telephone survey. Lateral radiographs of the knee of all patients were reviewed, and the slope of the tibia was measured using a standardised technique. Two fellowship-trained orthopaedic sports medicine specialists, one board-certified general orthopaedic surgeon, and two fellowship-trained musculoskeletal radiologists measured the tibial slope in all patients.

RESULTS

At a minimum of 10-year follow-up, there were four (8.3%) autograft and 13 (26.5%) allograft failures that required revision reconstruction. The overall average tibial slope of the nonfailure cohort was 9.4°. The overall average tibial slope of the failure cohort was 11.9° (P ​= ​0.0002). The average slope of the allograft failures was 11.5°compared with an average slope of 9.6° in the nonfailures (P ​= ​0.01). The average slope of the autograft failures was 13.1° compared with 9.3° in the nonfailures (P ​= ​0.011). The mean difference in tibial slope measurements was 0.665 (95% confidence interval: 0.569-0.750). The interrater reliability, as measured by the intraclass correlation coefficient, for tibial slope was 0.898 (95% confidence interval: 0.859-0.928). The Cronbach α was 0.904.

CONCLUSION

In a prospective, randomised trial of ACL reconstructions using either autograft or allograft, failures were associated with a significantly increased slope of the tibia compared with the nonfailures at 10-year follow-up.

Good Short-Term Clinical Outcomes and Low Rates of Return to Sports after Repeat Revision ACL Reconstruction

Repeat revision anterior cruciate ligament reconstruction (ACL-R) is a rare, demanding procedure and, as such, has not been well studied. Most of the available literature shows improved functional outcomes compared with preoperative state but inferior results when compared with primary ACL-R, particularly regarding return to preinjury level of sports. The purpose of this study was to assess functional outcomes in patients who had undergone repeat revision ACL-R. The secondary aims were to register return to sports, associated meniscal and/or chondral lesions, and evaluate radiological anatomical parameters. Nine patients between 2011 and 2017 were evaluated, who had a minimum follow-up of 2 years. Median age at repeat ACL-R was 32 years (interquartile range [IQR], 30-34 years) and the median follow-up was 27 months (IQR, 24-39 months). Data collected prior to surgery and at last follow-up included patient demographics, operative findings, physical examination findings including pivot shift and KT-1000 arthrometer measurement; Lysholm and International Knee Documentation Committee (IKDC) subjective scores; and return to sports and level using the Tegner score. Knee Injury and Osteoarthritis Outcome Score (KOOS) subjective score and radiographic anatomical parameters were recorded at last follow-up. Mean IKDC and Lysholm score improvement was 25 points (confidence interval [CI] 12-37) and 25 points (CI 11-39), respectively (p < 0.001). The median postoperative KOOS score was pain: 93 (IQR, 64-96); symptoms: 94 (IQR, 83-97); activities of daily life: 96 (IQR, 90-100); sports: 75 (IQR, 50-90); and quality of life: 50 (IQR, 43-81). Postoperative median side-to-side KT-1000 arthrometer difference was 2 mm (IQR, 1-8 mm). The median radiographic posterior tibial slope was 10 degrees (IQR, 9-10). One patient was considered a failure at 16 months postoperative. Only 44% (four out of nine) patients were able to return to their sports. None of these patients had a cartilage injury, while three out of five patients who did not return to their sports had International Cartilage Regeneration & Joint Preservation Society grade III or IV cartilage injury. Patients should be counseled on the challenging outcomes of repeat revision ACL-R. This is Level IV, therapeutic case series.

Collagen wrapping and local platelet-rich fibrin do not improve the survival rates of ACL repair with dynamic intraligamentary stabilization: a retrospective case series after ≥5 years postoperatively

PURPOSE

Anterior cruciate ligament (ACL) repair has been recommended as a treatment principle for ACL tears. Several authors have advocated a potential role for primary repair techniques in the ACL decision tree. However, long-term results have been controversial. This study aims to determine the survival of the primarily repaired ACL after dynamic intraligamentary stabilization (DIS) with and without augmentation.

METHODS

Between 2014 and 2019, 102 patients with isolated proximal ACL ruptures underwent DIS repair within 21 days from injury and were available for follow-up either clinically or telephonically after ≥5 years postoperatively. In 45 cases, DIS repair was augmented with collagen fleece wrapping, platelet-rich fibrin (PRF) or both. Failure was defined as traumatic re-rupture or conversion to ACL reconstruction. The patients being available for physical examination underwent a.-p. stability measurement with a KT-1000 device. Functional outcome was measured with the IKDC, Tegner and Lysholm scores. Kaplan-Meier survival analysis, Log-Rank Test and Binominal logistic regression were performed.

RESULTS

After a minimum 5-year follow-up, 71/102 (69.6%) DIS repairs were not re-reptured and clinically and/or subjectively stable. Augmentation did not improve survival rates (p = 0.812). The identified factors influencing failure were a younger age and a pre-injury Tegner activity level of ≥7. 95.7% of those patients with an intact ACL repair had normal or near normal knee function based on the IKDC scoring system.

CONCLUSIONS

The 5-year overall survival rate of DIS was 69.6%. Collagen fleece wrapping and local PRF application did not improve survival. Patients not suffering failure of repair demonstrated high satisfaction. Nevertheless, the results are inferior to those of established ACL reconstruction procedures.

LEVEL OF EVIDENCE

Case series, Level IV.

Optimal Graft Choice in Athletic Patients with Anterior Cruciate Ligament Injuries: Review and Clinical Insights

Anterior cruciate ligament (ACL) rupture is a common sporting-related knee injury with a potentially detrimental impact on the athlete’s career, yet there is no formal consensus on the optimal graft choice for reconstructing the ruptured ACL in this specific population. Options for reconstruction include autograft, allograft, and artificial grafts. However, each has associated failure risk and donor site morbidity. Our operational definition of the athlete is a skeletally mature individual participating in high level activity with the expectation to return to pre-injury level of activity. The athlete has unique injury characteristics, post-operative expectations, and graft demands that differ to the general population. Long-term outcomes are of particular importance given on-going mechanical demands on the reconstructed knee. Therefore, the purpose of this review is to consolidate current literature on the various ACL reconstruction graft options, with a focus on the optimal graft for returning the athlete to activity with the lowest rate of re-injury.

Notchplasty is associated with decreased risk of anterior cruciate ligament graft revision

PURPOSE

Despite influencing knee biomechanics and outcomes, the use of notchplasty at time of anterior cruciate ligament reconstruction (ACLR) has not been evaluated with regards to risk of secondary injury and revision. This study evaluates this association.

METHODS

42 patients (21.7-years, IQR = 19.0-27.5) that underwent primary then revision ACLR at a single institution were contrasted with a case matched control group of patients with grafts that did not fail. Patients were propensity score matched in a 1:2 ratio by age, gender, and date of index procedure. Post-hoc statistical correction was made for post-index procedure sports participation level.

RESULTS

Notchplasty was performed in 2 of 42 cases that went on to revision, and in 31 of 84 cases in the control group (p < 0.001). This was associated with reduced rates of revision ACLR (OR = 0.085, 95%CI = 0.019-0.378). A significant difference was seen in the post-ACLR activity level between groups (p = 0.028), with post-hoc testing highlighting those returning to competitive sport to be more likely to require subsequent revision (OR = 9.647, 95%CI = 1.947-47.795). Notchplasty remained significantly associated with (reduced) risk of revision surgery, despite the observed variation in post-ACLR activity (p = 0.001).

CONCLUSION

Individuals whose graft failed following ACLR were significantly less likely to have had notchplasty performed as part of their surgery than a control group who did not suffer graft reinjury. We propose that this may be due to decreased tensioning of the graft as the knee enters dynamic valgus, which may be of great relevance to athletes undergoing ACLR to enable return to sport.

Are 6-Month Functional and Isokinetic Testing Measures Risk Factors for Second Anterior Cruciate Ligament Injuries at Long-T Follow-Up?

INTRODUCTION

 Second anterior cruciate ligament (SACL) injuries are a devastating complication following return to sport (RTS). Appropriate and safe RTS criteria that reduce the risk of SACL injuries are needed. The goal of this study was to investigate the relationship between functional and isokinetic testing at 6 months following primary ACL reconstruction (ACLR) as risk factors for SACL injuries.

METHODS

 Patients with primary ACLR from 1990 to 2010 were identified. Those with 6-month postoperative functional and isokinetic testing and a minimum of 2-year follow-up were included. Functional testing included vertical jump, single-leg hop, and single-leg triple hop. Isokinetic testing included concentric quadriceps and hamstrings (HSs) strength at 60 and 180 degree/s speeds. Statistical analysis evaluated the significance of the various tests between those with and without a secondary tear.

RESULTS

 In total, 344 patients with a mean age of 26.0 ± 9.8 years at an average time of 9.1 ± 3.5 years of follow-up were analyzed. Fifty-nine patients (17%) experienced SACL injuries at an average time of 4.8 years following ACLR with 34 (58%) ipsilateral graft ruptures and 25 (43%) contralateral tears. Several isokinetic measures were significantly different between the NO SACL and the SACL groups: quadriceps 60 degree/s limb symmetry index (LSI) (75 vs. 82% p = 0.01), HS 60 degree/s LSI (92 vs. 97%, p = 0.04), quadriceps 180 degree/s involved/body weight (BW) (41 vs. 47%, p = 0.04), and HS 180 degree/s involved/BW (30 vs. 34%, p = 0.04). Patients with involved limb peak quadriceps torque value greater than 65 or 50% of BW (60 and 180 degree/s) had a 2.2 and 3.1 times higher risk of an SACL injury.

CONCLUSIONS

 Patients with certain elevated isokinetic scores in the injured limb at 6 months after ACLR experienced a higher rate of subsequent ACL injuries than those who had lower peak torque. Although a quantitative only analysis may not be sufficient to determine RTS criteria, clinicians should caution high-performing patients about the risk of subsequent ACL injury.

LEVEL OF EVIDENCE

 Cohort study; 3.

Is There an Association in Young Patients Between Quadriceps or Hamstring Strength After ACL Reconstruction and Graft Rupture?

Background:

Younger patients who sustain anterior cruciate ligament (ACL) ruptures are at high risk for reinjury after ACL reconstruction. Restoring muscle strength before return to sports (RTS) is regarded as an important factor in reducing the reinjury risk, and quadriceps and hamstring strength assessment is commonly included in RTS testing. However, it is not clear whether reduced strength is a risk factor for subsequent graft rupture in this patient population.

Purpose:

To investigate the association between quadriceps and hamstring strength at 12 months after primary ACL reconstruction and ACL graft rupture in young patients.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

The cohort consisted of 210 patients (100 men and 110 women) who were younger than 20 years at the time of primary ACL reconstruction with a hamstring tendon autograft and who had no previous contralateral ACL injury. Isokinetic strength testing (60 and 180 deg/s) of knee flexors and extensors was performed at 12 months postoperatively, and the limb symmetry index (LSI) for each strength outcome was calculated. RTS rates and the incidence of further ACL graft ruptures were recorded.

Results:

Measures of central tendency (mean and median) of LSI values ranged from 88 to 98. The percentage of patients with LSI ≥90 was 57% to 69% for quadriceps strength and 45% to 47% for hamstring strength. Overall, 19 patients (9%) sustained an ACL graft rupture. No significant differences were found between the patients who sustained an ACL graft rupture and those who did not in terms of quadriceps and hamstring strength at 12 months. No significant associations were found between achieving LSI ≥90 for quadriceps peak torque and subsequent ACL graft rupture.

Conclusion:

In young patients who underwent an ACL reconstruction, no association was noted between quadriceps and hamstring strength at 12 months postoperatively and subsequent graft ruptures. The role of strength testing as part of the RTS criteria after ACL reconstruction, and specifically the use of limb symmetry thresholds, warrants further investigation and clarification.

Paediatric Anterior Cruciate Ligament (ACL) Injuries: Current Concepts Review

BACKGROUND

Over the past two decades, there has been a documented increase in paediatric ACL injuries because of a rise in younger age sports participation at the competitive level, awareness about sports-related injuries, and advanced imaging modalities.

METHODS

A PubMed electronic database search was done, which revealed 1366 hits over the last five years (2016 - 2020). Finally, 37 articles that contributed to new findings were included. This review was conducted based on predefined research questions.

RESULTS AND CONCLUSION

Early surgical reconstruction is recommended in children due to the increasing demand for early return to sports and to prevent the instability that can lead to progressive cartilage and meniscal damage. With the evolution of several "physeal sparing" ACL reconstruction (ACLR) techniques, a favorable clinical outcome with less growth disturbance is achievable. Although different autograft options are available, hamstring autografts are most commonly preferred. A specific pattern of a bone bruise not extending into the metaphysis, and lateral meniscus tears are the most common associated injuries. Following paediatric ACLR, complications like graft rupture and contralateral ACL injuries are two to three folds higher than with adult ACLR. Unprepared early return to sports is one of the reasons for increased complication rates in children; thus, clearance criteria for return to sports need to be standardized, and early return to sports (< 9 months post ACLR) should be avoided. Neuromuscular training protocols are recommended to minimize complications like graft ruptures.

Graft Choice for Anterior Cruciate Ligament Reconstruction in Women Aged 25 Years and Younger: A Systematic Review

CONTEXT

Although anterior cruciate ligament (ACL) tears are relatively common in athletic populations, few studies have systematically reviewed graft choice in young women.

OBJECTIVE

To quantitatively and qualitatively examine reported outcomes for graft choice in women aged 25 years and younger undergoing primary ACL reconstruction.

DATA SOURCE

A systematic review was performed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. An electronic search in the PubMed (includes MEDLINE) and EMBASE databases was completed using a combination of key terms.

STUDY SELECTION

Studies were included if they reported graft choice outcomes in women aged 25 years and younger.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

The following information was extracted: title, author, year of publication, number of female patients and age, graft type, follow-up, and patient-reported outcome measures. The following outcome scores were identified as being reported or not reported by each study: graft failure, contralateral ACL (CACL) rupture, IKDC (International Knee Documentation Committee), graft survival (Kaplan-Meier), Lysholm, Tegner, KT-1000, kneeling pain, return to sport, and Lachman.

RESULTS

Of 1170 identified articles, 16 met inclusion criteria, reporting on 1385 female patients aged 25 years and younger. Comparison of 655 bone-patellar tendon-bone (BPTB) versus 525 hamstring tendon (HT) autografts showed significant differences in mean failure rate between BPTB autografts (6.13% ± 2.58%) and HT autografts (17.35% ± 8.19%), P = 0.001. No statistically significant differences in CACL failure rates were found between BPTB autografts and HT autografts (P = 0.25). Pooled results for IKDC were possible in 3 of the HT autograft studies, showing a mean score of 88.31 (95% CI 83.53-93.08). Pooled Lysholm score results were possible in 2 of the HT autograft studies, showing a mean score of 93.46 (95% CI 91.90-95.01).

CONCLUSION

In female patients aged 25 years and younger, BPTB autografts showed significantly less graft failure compared with HT autografts. However, BPTB autografts had comparable patient-reported outcomes compared with HT autografts with the available data. The overall state of evidence for graft choice in female patients aged 25 years and younger is low. Future studies should report statistics by age and sex to allow for further analysis of graft choice for this specific population that is known to be more vulnerable to ACL injury.

Differences in cellular and microstructural properties of the semitendinosus muscle tendon between young and adult patients

BACKGROUND

Poor outcomes associated with anterior cruciate ligament reconstruction in paediatric patients are a major concern. The tendon structure and its cellular characteristics are key factors that affect the mechanical properties of tendons. This study aimed to evaluate the effects of growth on the cellular and microstructural properties of the tendon of the semitendinosus muscle in humans.

METHODS

Semitendinosus muscle tendon samples from 76 patients who underwent ligament reconstruction were examined and divided into three groups: immature (10.8 ± 2.7 years old), young (16.5 ± 1.8 years old), and adult (35.2 ± 8.6 years old), based on age and the state of the epiphyseal plate in the distal femur. The number of tendon cells per unit area was assessed, and the major-to-minor-length ratio of the tendon cell nuclei was calculated to evaluate the shape of the nuclei using haematoxylin and eosin staining. The collagen fibril diameter and distribution were determined using electron microscopy.

RESULTS

The major-to-minor-length ratio of the tendon cell nuclei significantly increased with age (p-value; immature vs. young: 0.018, young vs adult: 0.001, immature vs adult: 0.001). The shape of the tendon cell nuclei was rounder in the immature group and more elongated in the adult group. A significant decrease in the number of tendon cells was observed with age (immature: 565 ± 134/mm², young: 356 ± 105/mm², adult: 272 ± 81/mm²; p-value: immature vs young: 0.001, young vs adult: 0.012, immature vs adult: 0.001). The mean fibril diameter in the immature group was significantly smaller (p-value: immature vs young: 0.018, young vs adult: 0.001, immature vs adult: 0.001). The distribution of the collagen fibrils changed from right skewed in the immature group to flat in the adult group.

CONCLUSIONS

The characteristics of the tendon cells and the microstructure of collagen in muscle tendons significantly changed with age.

Predictors of Graft Failure in Young Active Patients Undergoing Hamstring Autograft Anterior Cruciate Ligament Reconstruction With or Without a Lateral Extra-articular Tenodesis: The Stability Experience

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction (ACLR) has higher failure rates in young active patients returning to sports as compared with older, less active individuals. Augmentation of ACLR with an anterolateral procedure has been shown to reduce failure rates; however, indications for this procedure have yet to be clearly defined.

PURPOSE/HYPOTHESIS

The purpose of this study was to identify predictors of ACL graft failure in high-risk patients and determine key indications for when hamstring ACLR should be augmented by a lateral extra-articular tenodesis (LET). We hypothesized that different preoperative characteristics and surgical variables may be associated with graft failure characterized by asymmetric pivot shift and graft rupture.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were obtained from the Stability 1 Study, a multicenter randomized controlled trial of young active patients undergoing autologous hamstring ACLR with or without a LET. We performed 2 multivariable logistic regression analyses, with asymmetric pivot shift and graft rupture as the dependent variables. The following were included as predictors: LET, age, sex, graft diameter, tear chronicity, preoperative high-grade knee laxity, preoperative hyperextension on the contralateral side, medial meniscal repair/excision, lateral meniscal repair/excision, posterior tibial slope angle, and return-to-sports exposure time and level.

RESULTS

Of the 618 patients in the Stability 1 Study, 568 with a mean age of 18.8 years (292 female; 51.4%) were included in this analysis. Asymmetric pivot shift occurred in 152 (26.8%) and graft rupture in 43 (7.6%). The addition of a LET (odds ratio [OR], 0.56; 95% CI, 0.37-0.83) and increased graft diameter (OR, 0.62; 95% CI, 0.44-0.87) were significantly associated with lower odds of asymmetric pivot shift. The addition of a LET (OR, 0.40; 95% CI, 0.18-0.91) and older age (OR, 0.83; 95% CI, 0.72-0.96) significantly reduced the odds of graft rupture, while greater tibial slope (OR, 1.15; 95% CI, 1.01-1.32), preoperative high-grade knee laxity (OR, 3.27; 95% CI, 1.45-7.41), and greater exposure time to sport (ie, earlier return to sport) (OR, 1.18; 95% CI, 1.08-1.29) were significantly associated with greater odds of rupture.

CONCLUSION

The addition of a LET and larger graft diameter were significantly associated with reduced odds of asymmetric pivot shift. Adding a LET was protective of graft rupture, while younger age, greater posterior tibial slope, high-grade knee laxity, and earlier return to sport were associated with increased odds of graft rupture. Orthopaedic surgeons should consider supplementing hamstring autograft ACLR with a LET in young active patients with morphological characteristics that make them at high risk of reinjury.

Patient-Reported Outcome, Return to Sport, and Revision Rates 7-9 Years After Anterior Cruciate Ligament Reconstruction: Results From a Cohort of 2042 Patients

BACKGROUND

Long-term patient-reported outcome measures (PROMs), rates of return to sport, and revision risk after anterior cruciate ligament (ACL) reconstruction (ACLR) are not well understood.

PURPOSE

To provide long-term follow-up of PROMs, return-to-sport rates, and revision rates after ACLR and to identify predictors for poor outcome.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 2042 patients were included in an institutional ACL registry (2009-2013) and longitudinally followed. PROMs were completed preoperatively and at all follow-up time points. Questions regarding return to sport and knee stability were completed at final follow-up. Predictors for poor outcome on the International Knee Documentation Committee (IKDC) score were estimated in a regression model incorporating risk factors such as patient characteristics, graft choice, and concomitant injuries. Revision rates and risk of subsequent non-ACL surgeries were calculated.

RESULTS

Autografts were used in 76% of the patients (patellar tendon, 62%; hamstring grafts, 38%). Allografts were used in 24% of patients. The questionnaires were returned by 1045 (51.2%) patients at a mean of 7.2 years (range, 5.0-9.8 years) after surgery. Improvements in IKDC score of >30 points were sustained for all patient categories. The strongest predictor for lesser improvement in IKDC score was a cartilage lesion >2 cm2 identified during surgery. Male sex and college education completion were associated with improved IKDC scores. Meniscal lesions did not predict change) in the IKDC score. A total of 69% of patients had returned to sport after 8.1 years (range, 6.7-9.8 years). The main reason for not returning to sport was fear of reinjury. The revision rate was 7.2% after 9 years (range, 8-11 years), 13% of patients needed subsequent ipsilateral non-ACL surgery, and 6% underwent contralateral ACLR. The absence of a meniscal tear, younger age, and male sex were predictors for revision. Graft choice did not predict PROM results or revision risk.

CONCLUSION

Improvements in IKDC scores were sustained 7 years after ACLR. The strongest predictor for poor outcome was a cartilage lesion >2 cm2. Patients can expect a 70% return-to-sport rate and an 87% chance of their knee feeling stable during daily and athletic activities after 8 years. Young male patients have better PROM scores but a higher risk of revision. There is a 26% chance of subsequent knee surgery within 9 years, including a revision rate of 7%, subsequent non-ACL surgery to the operated knee in 13%, and a 6% chance of contralateral ACLR.

Limited evidence for graft selection in pediatric ACL reconstruction: a narrative review

Anterior cruciate ligament reconstruction is the preferred treatment to anterior cruciate ligament injury. With the increase in anterior cruciate ligament injuries in both adults and skeletally immature patients comes the need for individualized anterior cruciate ligament reconstruction graft selection whether it is the type of graft (auto vs. allograft) or the harvesting site (hamstrings, iliotibial band, quadriceps, patella). Several factors need to be considered preoperatively in order to optimize the patients’ recovery and restore anterior cruciate ligament strength and function. These include age and bone maturity, preoperative knee flexor/extensor strength, sport participation, patient’s needs and anatomical characteristics. This paper aims at bringing evidence supporting the use of a personalized approach in graft selection for faster and more efficient return to sport and propose a theoretical framework to support the approach.

Satisfactory patient-reported outcomes at 5 years following primary repair with suture tape augmentation for proximal anterior cruciate ligament tears

PURPOSE

An enhanced understanding of anterior cruciate ligament (ACL) healing and advancements in arthroscopic instrumentation has resulted in a renewed interest in ACL repair. Augmentation of a ligament repair with suture tape reinforces the ligament and acts as a secondary stabilizer. This study assesses the 5-year patient-reported outcomes of primary repair with suture tape augmentation for proximal ACL tears.

METHODS

Thirty-seven consecutive patients undergoing ACL repair with suture tape augmentation for an acute proximal rupture were prospectively followed up for a minimum of 5 years. Patients with midsubstance and distal ruptures, poor ACL tissue quality, retracted ACL remnants and multiligament injuries were excluded. Patient-reported outcome measures were collated using the Knee Injury and Osteoarthritis Outcomes Score (KOOS), Visual Analogue Pain Scale (VAS-pain), Veterans RAND 12-Item Health Survey (VR-12) and the Marx Activity Scale. Patients with a re-rupture were identified.

RESULTS

Three patients were lost to follow-up leaving 34 patients in the final analysis (91.9%). The mean KOOS at 5 years was 88.5 (SD 13.8) which improved significantly from 48.7 (SD 18.3) preoperatively (p < 0.01). The VAS score improved from 2.3 (SD 1.7) to 1.0 (SD 1.5) and the VR-12 score improved from 35.9 (SD 10.3) to 52.4 (SD 5.9) at 5 years (p < 0.01). However, the Marx activity scale decreased from 12.4 (SD 3.4) pre-injury to 7.3 (SD 5.2) at 5 years (p = 0.02). Six patients had a re-rupture (17.6%) and have since undergone a conventional ACL reconstruction for their revision surgery with no issues since then. These patients were found to be younger and have higher initial Marx activity scores than the rest of the cohort (p < 0.05).

CONCLUSION

Primary repair with suture tape augmentation for proximal ACL tears demonstrates satisfactory outcomes in 28 patients (82.4%) at 5-year follow-up. Six patients sustained a re-rupture and have no ongoing problems following treatment with a conventional ACL reconstruction. These patients were significantly younger and had higher initial Marx activity scores.

LEVEL OF EVIDENCE

Level IV.

Stable Lateral Meniscal Posterior Root Tears Left In Situ at Time of Anterior Cruciate Ligament Reconstruction Are of Minimal Long-Term Clinical Detriment

PURPOSE

The purpose of this study was to compare long-term patient-reported outcomes in patients undergoing anterior cruciate ligament (ACL) reconstruction with untreated stable lateral meniscal posterior root (LMPR) tears to those with an intact meniscus.

METHODS

Four hundred ninety-two subjects were followed for a minimum of 15-years post-ACL reconstruction and evaluated by an International Knee Documentation Committee questionnaire. The integrity of the meniscus was classified at surgery. Patients were grouped as either untreated injury to LMPR "with stable tear" (WST) group (n = 52) or intact lateral meniscus "no tear" (NT) group (n = 440). WST group included tears where those with a root avulsion within 9 mm of insertion and parrot beak tears with the integrity of the root attachment maintained. Outcomes were compared between groups.

RESULTS

ACL graft rupture occurred in 10% in the WST group and in 11% in the NT group (P = .78). For participants with an intact graft (n = 440), the mean International Knee Documentation Committee scores were 82, in the WST group, and 87, in the NT group (P = .03), with a small effect size of .32. The WST group had a worse mean pain severity score (P = .04) and higher frequency of pain (P = .03) than the NT group, but the effect size was small (P < 0.3). There was no difference in the overall knee function (P = .209) or International Knee Documentation Committee activity level (P = .882).

CONCLUSION

There was no adverse clinical outcome to leaving a stable LMPR tear in situ at the time of ACL reconstruction. LMPR tears left in situ were of minimal clinically significant long-term detriment, with outcomes similar to having an intact meniscus. There is an innate desire to fix the broken, but posterior meniscal root avulsions and stable parrot beak tears within 9 mm of insertion may not require intervention. At 15 years postinjury, most patients with a stable tear left in situ continue to enjoy an active lifestyle with a pain-free knee.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Postoperative Pain Is Associated With Psychological and Physical Readiness to Return to Sports One-Year After Anterior Cruciate Ligament Reconstruction

Purpose

To identify whether any patient factors, injury factors, or symptom severity scores are associated with either psychological or physical readiness to return to sport after anterior cruciate ligament reconstruction (ACLR).

Methods

Consecutive patients with an ACL injury that required surgical treatment were included in this study. All patients completed the single-legged hop testing and the Anterior Cruciate Ligament Return to Sport Index (ACL-RSI) at 1 year postoperatively. Multivariable regression analysis models were used to determine whether an independent relationship existed between baseline patient factors (age, sex, BMI, preinjury Marx Activity Score), injury factors (meniscal tear and chondral injury), physical symptoms (Knee Injury and Osteoarthritis Outcome Score [KOOS] for pain and symptoms), and the dependent variables of physical and psychological readiness to return to sport (single-legged hop and ACL-RSI).

Results

Of the 113 patients who were included, 37% were female, and the mean age of our population was 28.2 years (SD = 8.1). Multivariable regression models demonstrated that patient-reported pain symptoms at 1 year postoperatively, as measured by the KOOS pain subscale, was significantly associated with both ACL-RSI score (Beta estimate: 1.11 [95% CI: .62-1.60] P < .001) and the ability to pass the single-legged hop test (OR: 1.07 [95% CI: 1.004-1.142] P = .037).

Conclusions

Patients with higher reported pain levels at 1 year following ACLR have lower psychological and physical readiness to return to sport.

Level of Evidence

Level 3, retrospective cohort study.

Adolescents Have Twice the Revision Rate of Young Adults After ACL Reconstruction With Hamstring Tendon Autograft: A Study From the Swedish National Knee Ligament Registry

Background:

Previous studies have identified young age as a risk factor for anterior cruciate ligament (ACL) revision. However, few studies have looked separately at pediatric patients and adolescents with regard to outcomes after ACL reconstruction.

Purpose:

To determine whether patient age at ACL reconstruction affects the risk of undergoing revision surgery in young patients.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This study was based on data from the Swedish National Knee Ligament Registry. Patients aged 5 to 35 years who underwent a primary ACL reconstruction with a hamstring tendon autograft between January 1, 2005, and December 31, 2015, were included. The cohort was stratified into different age groups of pediatric patients, adolescents, and young adults to estimate patients with open, recently closed, and closed epiphyses, respectively. The primary endpoint was ACL revision. A multivariable Cox regression model was used to assess the ACL revision rate. The results were expressed as hazard ratios (HRs) and 95% CIs.

Results:

A total of 36,274 ACL reconstructions were registered during the study period. Of these, 2848 patients were included in the study: 47 pediatric patients (mean age, 13.6 years; range, 9-15 years), 522 adolescents (mean age, 17.4; range, 14-19 years), and 2279 young adults (mean age, 27.0; range, 20-35 years). A total of 31 patients (1.1%) underwent ACL revision within 2 years (0 pediatric patients, 9 adolescents [1.7%], and 22 young adults [1.0%]) and a total of 53 patients (2.6%) underwent ACL revision within 5 years (2 pediatric patients [6.9%], 15 adolescents [3.9%], and 36 young adults [2.2%]). The adolescent age group had a 1.91 times higher rate of ACL revision compared with the young adults (HR = 1.91 [95% CI, 1.13-3.21]; P = .015). There were no differences in revision rates between the pediatric age group and the young adults (HR = 2.93 [95% CI, 0.88-9.79]; P = .081).

Conclusion:

Adolescents had almost twice the rate of revision ACL reconstruction compared with young adults.

Prospective and Randomized Clinical Evaluation of Hamstring Versus Patellar Tendon Autograft for Anterior Cruciate Ligament Reconstruction in Soccer Players

Background:

Anterior cruciate ligament (ACL) reconstruction is usually performed with autologous bone–patellar tendon–bone (PT) or hamstring tendon (HT) graft. There has been only 1 randomized clinical trial examining ACL reconstruction with these grafts specifically in soccer players, and more studies comparing these graft types within a homogenous cohort such as soccer athletes may better highlight differences in outcomes.

Purpose:

To compare the results of ACL reconstruction with PT versus HT autograft in soccer players and to evaluate objective and subjective outcomes.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A total of 62 professional or semiprofessional soccer players (mean age, 25.1 years) with ACL injury were randomized to undergo reconstruction with PT or HT autograft by a single orthopaedic surgeon (n = 31 in each group). Outcome measures were recorded preoperatively and at 2 years postoperatively. The primary outcome was the modified Cincinnati Knee Rating System, and secondary outcomes were the objective and subjective International Knee Documentation Committee scores, Lachman test, pivot-shift test, anterior drawer test, and Lysholm score. The following variables were also evaluated postoperatively: return to soccer, level at return, graft rerupture, postoperative complications, anterior knee pain, patellar tendinitis, difficulty sprinting, and loss of kicking power.

Results:

The PT and HT groups were homogenous in terms of age, sex distribution, injured side, and time from injury to surgery, and there was no difference between them on any preoperative outcome score. At 2 years postoperatively, there were no differences between the groups on any outcome score; however, there were significantly fewer patients with anterior knee pain in the HT group compared with the PT group (7 [22.6%] vs 15 [48.4%], respectively; P = .03). Two patients from each group (2/31; 6.5%) sustained rerupture.

Conclusion:

There were no differences between soccer players who underwent different types of ACL reconstruction with the exception of anterior knee pain, which was more frequent in players who underwent reconstruction with PT graft.

Registration: NCT02642692 (ClinicalTrials.gov).

Optimizing outcomes of ACL surgery-Is autograft reconstruction the only reasonable option?

Anterior cruciate ligament (ACL) injuries occur at a high frequency in the United States with approximately 400,000 ACL reconstructions being performed each year. While ACL reconstruction is our current gold standard of treatment, it does not restore joint motion, or prevent the premature development of posttraumatic osteoarthritis (PTOA) in many patients. Thus, new treatments for an ACL injury, which are less invasive and minimize patient morbidity, including cartilage damage, are highly desirable. We have used a tissue-engineered approach to stimulate ligament healing, to improve upon current treatment options. In this review, we describe and discuss our work moving a tissue engineering strategy from the concept to bench, preclinical, clinical trials and ultimately FDA 510(k) de Novo approval, providing clinicians and patients with a viable alternative to ACL reconstruction.

The 50 Most Cited Articles in the Indications, Risk Factors, Techniques, and Outcomes of ACL Revision Surgery

The rate of anterior cruciate ligament (ACL) retear remains high and revision ACL reconstruction has worse outcomes compared with primaries. To make advances in this area, a strong understanding of influential research is necessary. One method for systematically evaluating the literature is by citation analysis. This article aims to establish and evaluate "classic" articles. With consideration of these articles, this article also aims to evaluate gaps in the field and determine where future research should be directed. The general approach for data collection and analysis consisted of planning objectives, employing a defined strategy, reviewing search results using a multistep and multiauthor approach with specific screening criteria, and analyzing data. The collective number of citations for all publications within the list was 5,203 with an average of 104 citations per publication. "Biomechanical Measures during Landing and Postural Stability Predict Second Anterior Cruciate Ligament Injury after Anterior Cruciate Ligament Reconstruction and Return to Sport" by Paterno et al contained both the highest number of total citations and the highest number of citations per year, with 403 total citations and 43.9 citations per year. The most recurring level of evidence were level II (n = 18) and level III (n = 17). "Clinical Outcomes" was the most common article type (n = 20) followed by "Risk Factors" (n = 10). The American Journal of Sports Medicine had the highest recorded Cite Factor with over 50% of the articles (n = 27) published. The most productive authors included R.W. Wright (n = 6), S.D. Barber-Westin (n = 5), F.R. Noyes (n = 5), and K.P. Spindler (n = 5). Historically, influential studies have been published in the realms of clinical outcome and risk factor identification. It has been established that revision ACL reconstruction has worse outcomes and more high-level studies are needed. Additionally, prospective studies that apply the knowledge for current known risk factor mitigation are needed to determine if graft tear rates can be lowered.

Association Between Graft Choice and 6-Year Outcomes of Revision Anterior Cruciate Ligament Reconstruction in the MARS Cohort

BACKGROUND

Although graft choice may be limited in the revision setting based on previously used grafts, most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome.

HYPOTHESIS

In the ACL revision setting, there would be no difference between autograft and allograft in rerupture rate and patient-reported outcomes (PROs) at 6-year follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients who had revision surgery were identified and prospectively enrolled in this cohort study by 83 surgeons over 52 sites. Data collected included baseline characteristics, surgical technique and pathology, and a series of validated PRO measures. Patients were followed up at 6 years and asked to complete the identical set of PRO instruments. Incidence of additional surgery and reoperation because of graft failure were also recorded. Multivariable regression models were used to determine the predictors (risk factors) of PROs, graft rerupture, and reoperation at 6 years after revision surgery.

RESULTS

A total of 1234 patients including 716 (58%) men were enrolled. A total of 325 (26%) underwent revision using a bone-patellar tendon-bone (BTB) autograft; 251 (20%), soft tissue autograft; 289 (23%), BTB allograft; 302 (25%), soft tissue allograft; and 67 (5%), other graft. Questionnaires and telephone follow-up for subsequent surgery information were obtained for 809 (66%) patients, while telephone follow-up was only obtained for an additional 128 patients for the total follow-up on 949 (77%) patients. Graft choice was a significant predictor of 6-year Marx Activity Rating Scale scores (P = .024). Specifically, patients who received a BTB autograft for revision reconstruction had higher activity levels than did patients who received a BTB allograft (odds ratio [OR], 1.92; 95% CI, 1.25-2.94). Graft rerupture was reported in 5.8% (55/949) of patients by their 6-year follow-up: 3.5% (16/455) of patients with autografts and 8.4% (37/441) of patients with allografts. Use of a BTB autograft for revision resulted in patients being 4.2 times less likely to sustain a subsequent graft rupture than if a BTB allograft were utilized (P = .011; 95% CI, 1.56-11.27). No significant differences were found in graft rerupture rates between BTB autograft and soft tissue autografts (P = .87) or between BTB autografts and soft tissue allografts (P = .36). Use of an autograft was found to be a significant predictor of having fewer reoperations within 6 years compared with using an allograft (P = .010; OR, 0.56; 95% CI, 0.36-0.87).

CONCLUSION

BTB and soft tissue autografts had a decreased risk in graft rerupture compared with BTB allografts. BTB autografts were associated with higher activity level than were BTB allografts at 6 years after revision reconstruction. Surgeons and patients should consider this information when choosing a graft for revision ACL reconstruction.

Association of Prior Anterior Cruciate Ligament Tear With Decreased Career Longevity in Women's National Basketball Association

Background

The incidence of anterior cruciate ligament (ACL) injuries in women's basketball exceeds that of men. There is a paucity of data regarding career performance in Women's National Basketball Association (WNBA) athletes with a history of ACL reconstruction.

Purpose

To determine whether WNBA athletes with a history of ACL injury prior to professional play have reduced career game utilization, defined as games played and started and minutes per game (MPG), as well as statistical performance, defined by player efficiency rating (PER).

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 42 WNBA players from 1997 to 2018 who had a history of ACL reconstruction before entering professional leagues. Body mass index (BMI), age, and position were collected for each player. Career data and performance statistics were likewise collected for each player's entire WNBA career. A control group of WNBA players with no history of ACL injury were matched by position, BMI, and age at the time of WNBA debut. Statistics compared game utilization and performance to assess the impact of ACL reconstruction.

Results

Athletes who sustained an ACL tear before entering the league played in fewer games per season in their first 3 professional seasons compared with healthy controls (24.2 ± 8.4 vs 28.2 ± 6.1; P = .02). Among athletes with a history of ACL reconstruction, 11 (26.2%) played only a single WNBA season, while no control athletes played in just 1 season. Additionally, athletes who had a previous ACL tear started significantly fewer games per season (9.0 ± 9.4 vs 14.0 ± 9.0; P < .01) and played fewer MPG (15.5 ± 7.2 vs 20.7 ± 5.5; P < .01) during their WNBA career. Athletes with a history of ACL tear had significantly shorter WNBA careers (4.8 ± 4.1 vs 8.1 ± 3.3 seasons; P < .001). Total professional play duration (WNBA + overseas) was significantly reduced in players with an ACL tear compared with controls (P < .05). PER was not significantly different between cohorts at any time point.

Conclusion

WNBA athletes with a history of an ACL tear before professional play had decreased career game utilization and workload throughout their career despite having similar PER compared with healthy controls.

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.

Autograft diameter in ACL reconstruction: size does matter

BACKGROUND

Anterior cruciate ligament injuries are commonly seen in orthopedic surgery practice. Although anterior cruciate ligament reconstruction (ACLR) has come a long way, the causes of failure have yet to be fully understood.

OBJECTIVE

The aim of this study was to investigate whether or not the intraoperative 4-strand hamstring autograft diameter does in fact influence the failure rates of ACLR.

METHODS

Retrospective intraoperative data were collected from ACLR patients from the only tertiary center available in Kuwait. Patients who underwent ACLR from 2012 to 2018 for isolated ACL injuries were included in this study, allowing for a 24 month follow-up period The cohorts were categorized into 3 groups: patients with graft size≤8mm, 2, patients with graft sizes≥8mm with 4-strands and patients with graft sizes≥8mm with 4-strands or more. ANOVA analysis was applied to address group differences between mean graft size and strand numbers and subsequently the failure rates for each group. In addition, the Mann-Whitney U test was used to investigate the relationship between revision and initial ACL graft size.

RESULTS

Out of the 711 out of 782 patients were included in this study. Only 42.6% of the patients did not need more than 4-strands to achieve an 8mm sized autograft. The patients who had autografts≤8mm in this study accounted for 17.1% of the population. About 7.2% of these patients required revision surgery. Patients with a 4-strand autograft size that was less than 8mm were 7.2 times more at risk for ACLR failure (RR=7.2, 95% CI: 6.02; 8.35, p=0.007).

CONCLUSIONS

There is a significant correlation between 4-strand autograft diameter size and the need for ACLR revision surgery.

LEVEL OF EVIDENCE

IV case series.