Similar risk of ACL graft revision for alpine skiers, football and handball players: the graft revision rate is influenced by age and graft choice

ACL Graft Selection Based on Age and Sport

Background

The issue of graft selection in anterior cruciate ligament (ACL) reconstruction continues to be debated in the literature. It has been reported in the literature that different graft types give different results, especially in different demographic characteristics (age, sex) and different sports. In this study, we attempted to provide an overview of how graft selection should be made according to demographic characteristics (age, sex) and sport types.

Indications

In this study, we tried to review the studies in the literature that compared graft types in ACL reconstruction according to age, sex, or type of sport.

Technique Description

A narrow review of the literature was performed to compare graft selection specific to different sports.

Results

There is no perfect graft selection for everyone. Given the distinct characteristics of each sport branch, including the grade of pivoting, frequency of repeated movements, and expectations, it is evident that dedicated research is required for each sport. Comparative studies on graft selection specific to each sport may increase the accuracy of the selection.

Discussion/Conclusion

A review of the literature reveals a paucity of studies on the selection and outcomes of grafts in different sports. When choosing a graft for ACL reconstruction, factors such as age, sex, sport type, and expectations should be taken into consideration and a personalized decision should be made.

Patient Consent Disclosure Statement

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Anterior cruciate ligament primary repair revision rates are increased in skeletally mature patients under the age of 21 compared to reconstruction, while adults (>21 years) show no significant difference: A systematic review and meta-analysis

PURPOSE

To evaluate the impact of age as a risk factor on the revision rates of anterior cruciate ligament (ACL) primary repair (ACLPR), dynamic intraligamentary stabilization (DIS) and bridge-enhanced ACL restoration (BEAR) compared to ACL reconstruction (ACLR).

METHODS

A systematic literature search was performed for comparative studies comparing outcomes for ACLPR, DIS or BEAR to ACLR. A random-effects meta-analysis was performed to assess nondifferentiated and age-differentiated (skeletally mature patients ≤21 and >21 years) ACL revision and reoperation risk, as well as results for subjective outcomes. Methodological study quality was assessed using the Risk of Bias Tool 2.0c and Methodological Index for Nonrandomized Studies tools.

RESULTS

A total of 12 studies (n = 1277) were included. ACLR demonstrated a lower nonage-stratified revision risk at 2 years versus ACLPR, DIS and BEAR, but a similar revision risk at 5 years when compared to DIS. However, an age-stratified analysis demonstrated a significantly increased ACLPR revision risk as compared to ACLR in skeletally mature patients ≤21 years of age (risk ratios [RR], 6.33; 95% confidence interval [CI], 1.18-33.87, p = 0.03), while adults (>21 years) showed no significant difference between groups (RR, 1.48; 95% CI, 0.25-8.91, n.s.). Furthermore, DIS reoperation rates were significantly higher than respective ACLR rates (RR, 2.22; 95% CI, 1.35-3.65, p = 0.002), whereas BEAR (RR, 1.07; 95% CI, 0.41-2.75, n.s.) and ACLPR (RR, 0.81; 95% CI, 0.21-3.09, n.s.) showed no differences. IKDC scores were equivalent for all techniques. However, ACLPR exhibited significantly better FJS (mean difference, 11.93; 95% CI, 6.36-17.51, p < 0.0001) and Knee injury and Osteoarthritis Outcome Score Symptoms (mean difference, 3.01; 95% CI, 0.42-5.60, p = 0.02), along with a lower Tegner activity reduction.

CONCLUSIONS

ACLPR in skeletally mature patients ≤21 years of age is associated with up to a six-fold risk increase for ACL revision surgery compared to ACLR; however, adults (>21 years) present no significant difference. Based on the current data, age emerges as a crucial risk factor and should be considered when deciding on the appropriate treatment option in proximal ACL tears.

LEVEL OF EVIDENCE

Level III.

Satisfactory 5-year functional outcomes following primary ACL reconstructions from the UK National Ligament Registry

PURPOSE

The aim of this study was to describe the 10-year findings from the UK National Ligament Registry (NLR).

METHODS

A retrospective review was performed for prospectively collected data on the NLR between January 2013 and December 2022. All patients who underwent primary ACL reconstruction (ACLR) on the registry were included. Surgical characteristics were analysed, including surgeon grade and case volume, concomitant knee procedures, venous thromboembolic prophylaxis, graft characteristics, femoral and tibial tunnel drilling, and fixation methods. Clinical outcomes were collected preoperatively and at 6 months, 1 year, 2 years and 5 years following the index procedure.

RESULTS

During the study period, 17,492 unilateral ACLR procedures were recorded. Autograft was used in 98%, most commonly a combined semitendinosus and gracilis graft (77%) or patella tendon graft (31%). Allograft was used in only 1% of the patients. In 52% of cases, ACLR was associated with an additional procedure, with isolated medial meniscal surgery being the most common (21%). Femoral tunnel drilling was mostly performed through an anteromedial portal (73%) and tibial tunnel drilling using an outside-in technique (92%). The most common method of femoral graft fixation was with an Endobutton fixed loop suspensory device (77%), while interference screws predominated for tibial tunnel fixation (86%). Patients who underwent ACLR surgery showed significant improvement in their functional outcome scores at six months, 1 year, 2 years and 5 years postoperatively.

CONCLUSION

Data from the NLR shows a detailed description of the current trends and evolution of ACLR in the United Kingdom over the last 10 years. Satisfactory functional outcomes were observed 5 years postoperatively. This study provides useful information on the prevalence of ACL-associated injuries and current surgical techniques with the aim of improving the quality of clinical care and patients' outcomes. Moreover, it provides surgeons with a benchmark against which to compare current practices and functional outcomes following ACLR across the United Kingdom.

LEVEL OF EVIDENCE

Level III.

The Posterior Tibial Slope Is Not Associated With Graft Failure and Functional Outcomes After Anatomic Primary Isolated Anterior Cruciate Ligament Reconstruction

BACKGROUND

Biomechanical studies have shown that an increased medial posterior tibial slope (MPTS) may affect anteroposterior knee laxity and tibial shear forces, ultimately increasing the risk for graft failure after anterior cruciate ligament (ACL) reconstruction. Previous clinical studies have, however, reported inconclusive results.

PURPOSE

The purpose of this study was to evaluate the relationship between the MPTS and graft failure as well as functional outcomes after anatomic primary isolated ACL reconstruction using a hamstring tendon autograft. It was hypothesized that an increased MPTS would be associated with a higher ACL graft failure rate. Furthermore, a higher MPTS would negatively correlate with functional outcomes in patients without ACL graft failure.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Consecutive patients who underwent isolated primary ACL reconstruction with an anteromedial portal drilling technique between January 2011 and December 2019 were retrospectively reviewed. The MPTS was measured on preoperative lateral knee radiographs. At a minimum of 24 months postoperatively, the ACL graft failure rate and patient-reported outcome measures (PROM; International Knee Documentation Committee subjective knee form, Lysholm score, Tegner Activity Scale, visual analog scale for pain and subjective instability) were evaluated. Differences in the MPTS between patients with and without ACL graft failure as well as the frequency of graft failure between those with an MPTS <12° and those with an MPTS ≥12° were assessed for statistical significance. Binary logistic regression analysis was performed to stratify the risk of graft failure with the following variables: MPTS, age at surgery, and sex. Correlation analysis was performed to evaluate the relationship between the MPTS and PROM in patients without ACL graft failure.

RESULTS

In total, 326 patients were included (median follow-up, 71.0 months [IQR, 49.0-104.0 months]). There was no significant difference in the MPTS between patients with and without graft failure (10.6°± 3.2° vs 11.2°± 2.8°, respectively; P = .264). Additionally, there was no significant difference in the frequency of graft failure between patients with an MPTS <12° and those with an MPTS ≥12° (15.6% vs 16.5%, respectively; P = .835). Binary logistic regression showed that younger age at the time of surgery (odds ratio, 1.069 [95% CI, 1.031-1.109]) was associated with graft failure; sex and MPTS were not associated with graft failure. In patients without ACL graft failure, there was no significant correlation between the MPTS and PROM.

CONCLUSION

In patients who underwent anatomic primary isolated ACL reconstruction, an increased MPTS was not associated with a higher rate of graft failure or inferior functional outcomes. Younger age was a significant nonmodifiable risk factor for ACL graft failure.

Risk Factors for Revision or Rerupture After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

BACKGROUND

The rerupture or need for revision after anterior cruciate ligament reconstruction (ACLR) is a serious complication. Preventive strategies that target the early identification of risk factors are important to reduce the incidence of additional surgery.

PURPOSE

To perform a systematic review and meta-analysis to investigate risk factors for revision or rerupture after ACLR.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

Literature searches were performed in PubMed, Embase, and Web of Science from database inception to November 2021 and updated in January 2022. Quantitative, original studies reporting potential adjusted risk factors were included. Odds ratios (ORs) were calculated for potential risk factors.

RESULTS

A total of 71 studies across 13 countries with a total sample size of 629,120 met the inclusion criteria. Fifteen factors were associated with an increase in the risk of revision or rerupture after ACLR: male sex (OR, 1.27; 95% CI, 1.14-1.41), younger age (OR, 1.07; 95% CI, 1.05-1.08), lower body mass index (BMI) (OR, 1.03; 95% CI, 1.00-1.06), family history (OR, 2.47; 95% CI, 1.50-4.08), White race (OR, 1.32; 95% CI, 1.08-1.60), higher posterolateral tibial slope (OR, 1.15; 95% CI, 1.05-1.26), preoperative high-grade anterior knee laxity (OR, 2.30; 95% CI, 1.46-3.64), higher baseline Marx activity level (OR, 1.07; 95% CI, 1.02-1.13), return to a high activity level/sport (OR, 2.03; 95% CI, 1.15-3.57), an ACLR within less than a year after injury (OR, 2.05; 95% CI, 1.81-2.32), a concomitant medial collateral ligament (MCL) injury (OR, 1.62; 95% CI, 1.31-2.00), an anteromedial portal or transportal technique (OR, 1.36; 95% CI, 1.22-1.51), hamstring tendon (HT) autografts (vs bone-patellar tendon-bone [BPTB] autografts) (OR, 1.60; 95% CI, 1.40-1.82), allografts (OR, 2.63; 95% CI, 1.65-4.19), and smaller graft diameter (OR, 1.21; 95% CI, 1.05-1.38). The other factors failed to show an association with an increased risk of revision or rerupture after ACLR.

CONCLUSION

Male sex, younger age, lower BMI, family history, White race, higher posterolateral tibial slope, preoperative high-grade anterior knee laxity, higher baseline Marx activity level, return to a high activity level/sport, an ACLR within less than a year from injury, a concomitant MCL injury, an anteromedial portal or transportal technique, HT autografts (vs BPTB autografts), allografts, and smaller graft diameter may increase the risk of revision or rerupture after ACLR. Raising awareness and implementing effective preventions/interventions for risk factors are priorities for clinical practitioners to reduce the incidence of revision or rerupture after ACLR.

Anatomical Single-Bundle Anterior Cruciate Ligament Reconstruction Using a Calcium Phosphate-Hybridized Tendon Graft with More than an Average of 5 Years of Follow-Up: A Follow-Up Study of a Randomized Controlled Trial

Calcium phosphate (CaP)-hybridized tendon grafting using an alternate soaking process improves tendon-to-bone healing in anterior cruciate ligament (ACL) reconstructions. This study aimed to compare bone tunnel enlargement, knee osteoarthritis, and clinical results between CaP-hybridized tendon grafting and conventional grafting in anatomical single-bundle ACL reconstruction. This study was a follow-up of a randomized controlled trial. Between July 2011 and December 2015, 90 patients underwent unilateral anatomical single-bundle ACL reconstructions and were randomly assigned to the CaP-hybridized tendon grafting (CaP group, n = 45; age, 27.1 [14-54] years; sex, 21 males and 24 females) or conventional grafting (control group, n = 45; age, 22.9 [13-58] years; sex, 26 males and 19 females). The randomization was performed according to the days of the week when the patients first visited the outpatient. The CaP-hybridized tendon grafting was created intraoperatively. The tendon grafts were soaked in a calcium solution for 30 s. After that, the tendon grafts were soaked in a NaHPO4 solution for 30 s. This soaking cycle between the calcium solution and the NaHPO4 solution was repeated 10 times. The bone tunnel enlargement, osteoarthritis grade, clinical score, and sports level were evaluated in patients who could be followed up for >3 years (CaP group, n = 20, average follow-up period 6.0 [5.1-6.9] years; control group, n = 15, average follow-up period 5.6 [4.3-6.9] years). Clinical scores, sports levels, and osteoarthritis grades were analyzed using a generalized linear mixed model (GLMM) based on repeated measurement data from preoperative and final observations, with time, group, sex, age, and BMI as fixed effects and the effect of individual differences as variable effects. In addition, bone-tunnel enlargements were analyzed using generalized linear models (GLM) with group, sex, age, and BMI as the main effects. Compared with the control group, the CaP group exhibited significantly reduced bone-tunnel enlargement on the femoral side (anteroposterior diameter; CaP group, 7.9% [-1.1-16.8] vs. control group, 29.2% [17.9-40.5], p = 0.004, MCID 16.05, proximal-distal diameter; CaP group, 7.9% [-1.9-17.8] vs. control group, 22.8% [10.9-34.7], p = 0.062, MCID 15.00). The osteoarthritis grades progressed in both groups (p < 0.001). The clinical scores and sports levels were not significantly different between the groups. This study suggests that the calcium phosphate-hybridized tendon graft reduces femoral bone-tunnel enlargement after anatomical single-bundle anterior cruciate ligament reconstruction in an average >5-year follow-up period. A longer follow-up period is necessary to reveal the clinical effects of the calcium phosphate-hybridized tendon grafts in anterior cruciate ligament reconstruction.

Two-Dimensional Magnetic Resonance Imaging in Preparation for Autograft Anterior Cruciate Ligament Reconstruction Demonstrates Quadriceps Tendon Is Thicker Than Patellar Tendon

Purpose

The purpose of this study was to assess patellar tendon (PT) and quadriceps tendon (QT) thickness on preoperative magnetic resonance imaging (MRI), in both the sagittal and axial planes, at multiple points along each tendon, and to correlate these findings to anthropometric patient data before anterior cruciate ligament (ACL) surgery.

Methods

Patients who underwent PT or QT autograft ACL reconstruction between 2020 and 2022 and who had preoperative MRIs with adequate visualization of the proximal QT and distal PT were retrospectively identified. Patient demographics were recorded (age, height, weight, sex, injury side). Preoperative MRI measurements were performed by 3 independent examiners using standardized protocol. Preoperative MRI measurements were the QT anterior-posterior (AP) thickness at 1, 2, and 4 cm from the proximal patella on axial and sagittal MRI images at the central aspect of the tendon, as well as PT AP thickness at 1, 2, and 4 cm from the distal patella on axial and sagittal MRI images at the central aspect of the tendon.

Results

Forty-one patients (21 females, 20 males) were evaluated, with a mean age of 33.4 years. The quadriceps tendon was significantly thicker than the patellar tendon at all measured locations (P < .0001) with average QT versus PT thickness (in mm) at each level sagittal 1 cm (7.13 vs 4.35), sagittal 2 cm (7.41 vs 4.44), sagittal 4 cm (7.26 vs 4.81), axial 1 cm (7.35 vs 4.50), axial 2 cm (7.63 vs 4.47), axial 4 cm (7.46 vs 4.62), respectively. There were no significant correlations between tendon size and patient body mass index.

Conclusions

The quadriceps tendon is significantly thicker than the patellar tendon at 1, 2, and 4 cm from the patella in both males and females based on preoperative MRI before ACL surgery.

Clinical relevance

Investigating the thickness of the tendons available for autograft harvest before surgery will give us a better understanding of tendon anatomy in the setting of ACL reconstruction.

Comparative Study of ACL Reconstruction With Hamstring Versus Patellar Tendon Graft in Young Women: A Cohort Study From the New Zealand ACL Registry

BACKGROUND

Young female athletes are a specific population that is at high risk of primary anterior cruciate ligament (ACL) rupture and subsequent graft failure. Despite large numbers of ACL reconstructions being carried out in young women, there is limited analysis of outcomes in this group, leading to low levels of evidence for graft choice.

PURPOSE

To assess the effect of graft choice on ACL reconstruction failure rates among young women in New Zealand.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Prospective data captured by the New Zealand ACL Registry between April 2014 and March 2022 were reviewed. Young women aged 15 to 20 years were included. The primary outcome measure was ACL graft failure during the study period, with the key independent variable being graft type, either patellar or hamstring tendon autograft. This is presented as the rate per 100 patient-years and is compared between the 2 groups using the hazard ratio generated from a Cox proportional hazards regression. Secondary outcome measures were Marx activity scores and the Knee injury and Osteoarthritis and Outcome Score patient-reported outcome measure.

RESULTS

A total of 1261 primary ACL reconstructions in young women aged 15 to 20 years were reviewed. Hamstring tendon grafts were used in 797 (63%) reconstructions and patellar tendon graft in 464 (37%) reconstructions. Patients with a hamstring tendon graft had a graft failure rate of 7.7% compared with 1.1% in patients with a patellar tendon graft (hazard ratio, 6.1; 95% CI, 2.4-15.1; P < .001). The number of failures per 100 person-years was significantly higher in the hamstring group (2.05) compared with the patellar tendon group (0.37). No difference was noted at final follow-up between the hamstring tendon and patellar tendon groups when comparing patient-reported outcome measures during the follow-up period.

CONCLUSION

In the young female population of this study, the use of a patellar tendon graft was associated with reduced risk of graft failure and was not associated with an increase in knee morbidity. This highlights the importance of informed decision-making in this high-risk population when considering ACL reconstruction graft type.

Anatomic anterior cruciate ligament reconstruction: Freddie Fu's paradigm

Anterior cruciate ligament (ACL) reconstruction techniques have evolved over the past four decades. There is evidence that non-anatomic reconstruction techniques, such as traditional transtibial drilling, fail to recreate the native anatomy of the ACL, which can lead to increased rotatory knee instability, revision risk, and post-traumatic osteoarthritis. Anatomic ACL reconstruction has emerged as the gold standard, with the goal of restoring the patient's native anatomy and knee kinematics. This review will summarise the relevant anatomy, modern anatomic ACL reconstruction techniques, and literature supporting anatomic ACL reconstruction as the new paradigm. LEVEL OF EVIDENCE: Level V, review article.

Multiple revision anterior cruciate ligament reconstruction: not the best but still good

PURPOSE

Given the paucity of literature on the re-revision of ACL, the current study was undertaken. The purpose of this systematic review was to synthesise and qualitatively assess the currently available evidence in the literature regarding the re-revision of ACL reconstruction (rrACLR).

METHODS

A systematic review was conducted based on the PRISMA guidelines. The following search terms were used in the title, abstract and keywords fields: "ACL" or "anterior cruciate ligament" AND "revision" or "multiple" or "repeat". The outcome data extracted from the studies were the Lysholm score, Subjective IKDC, Marx Score, Tegner, Marx Score, KOOS score, radiological changes and the rate of return to sports. Complications, failures and/or revision surgery were also analysed.

RESULTS

The cohort consisted of 295 patients [191 (64.7%) men and 104 (35.3%) women] with a mean age of 29.9 ± 2.8 years (range 14-58 years) from 10 studies. The mean postoperative follow-up (reported in all studies except one) was 66.9 ± 44.7 months (range 13-230.4 months). Associated injuries were 103 (34.9%) medial meniscus tears, 57 (19.3%) lateral meniscus tears, 14 (4.7%) combined medial plus lateral meniscus tears, 11 (3.7%) meniscal tears (not specified), 252 (85.4%) cartilage lesions, 6 (2.0%) medial collateral ligament injury and 2 (0.7%) lateral collateral ligament injuries. In 47 (15.9%) patients an extra-articular plasty was performed for the anterolateral ligament. In all studies that reported pre- and post-operative IKDC (subjective and objective) and Lysholm score, there was a significant improvement compared to the pre-operative value (p < 0.05). At the final follow-up, laxity measured with KT-1000 was found to be 2.2 ± 0.6 mm. 31 (10.5%) out of 295 patients returned to their pre-injury activity level. A total of 19 (6.4%) re-ruptures were found, while only 4 (1.4%) complications (all minors) were reported, out of which 2 (0.7%) were superficial infections, 1 (0.3%) cyclops lesion and 1 (0.3%) flexion loss.

CONCLUSION

Multiple revisions of anterior cruciate ligament reconstruction allow acceptable clinical results and a good degree of knee stability with a low rate of subsequent new re-ruptures but the possibility of regaining pre-injury sports activity is poor; whenever possible, it is preferred to revise the ligament in one stage. This surgery remains a challenge for orthopaedic surgeons and many doubts persist regarding the ideal grafts, additional extra-articular procedures and techniques to use.

LEVEL OF EVIDENCE

IV.

STUDY REGISTRATION

PROSPERO-CRD42022352164 ( https://www.crd.york.ac.uk/prospero/ ).

High revision arthroscopy rate after ACL reconstruction in men's professional team sports

PURPOSE

The study analysed unique data on anterior cruciate ligament (ACL) injuries among German professional male team sports over five consecutive seasons with the aim of improving medical outcomes in the future. Sport-specific differences in injury occurrence, concomitant injuries, timing of ACL reconstruction, graft type selection and short-term complications were examined.

METHODS

This retrospective study analysed trauma insurance data on all complete ACL tears from players with at least one competitive match appearance in the two highest divisions of German male basketball, ice hockey, football and handball. Each complete ACL tear registered by clubs or physicians between the 2014/15 and 2018/19 seasons with the German statutory accidental insurance for professional athletes (VBG) as part of occupational accident reporting was included.

RESULTS

In total, 189 out of 7517 players (2.5%) sustained an ACL injury, mainly in handball (n = 82; 43.4%) and football (n = 72; 38.1%) followed by ice hockey (n = 20; 10.6%) and basketball (n = 15; 7.9%).Seventeen players (9.0%) also sustained a second ACL injury. Thus, 206 ACL injuries were included in the analysis. The overall match incidence of ACL injuries was 0.5 per 1000 h and was highest in handballs (1.1 injuries per 1000 h). A total of 70.4% of ACL injuries involved concomitant injury to other knee structures, and 29.6% were isolated ACL injuries. The highest rate of isolated ACL injuries was seen in ice hockey (42.9%). All ACL injuries, except for one career-ending injury, required surgery. In the four analysed team sports, hamstring tendons (71.4%) were the most commonly used grafts for ACL reconstruction; football had the highest percentage of alternative grafts (48.7%). During rehabilitation, 22.9% of all surgically treated ACL injuries (n = 205) required at least two surgical interventions, and 15.6% required revision arthroscopy. The main cause of revision arthroscopy (n = 32; 50.0%) was range-of-motion deficit due to arthrofibrosis or cyclops formation.

CONCLUSION

The present study shows an overall high rate of revision arthroscopy after ACLR (15.6%), which should encourage surgeons and therapists to evaluate their treatment and rehabilitation strategies in this specific subpopulation. Hamstring tendon grafts are most commonly used for ACL reconstruction but have the highest revision and infection rates. Handball shows the highest ACL injury risk of the four evaluated professional team sports. Concomitant injuries occur in the majority of cases, with the highest share of isolated ACL injuries occurring in ice hockey.

LEVEL OF EVIDENCE

Level III.

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

PURPOSE

To investigate the influence of surgeon-related factors and clinic routines on autograft choice in primary anterior cruciate ligament reconstruction (ACLR).

METHODS

Data from the Swedish National Knee Ligament Registry (SNKLR), 2008-2019, were used to study autograft choice (hamstring; HT, patellar; PT, or quadriceps tendon; QT) in primary ACLR. Patient/injury characteristics (sex, age at surgery, activity at time of injury and associated injuries) and surgeon-/clinic-related factors (operating volume, caseload and graft type use) were analyzed. Surgeon/clinic volume was divided into tertiles (low-, mid- and high-volume categories). Multivariable logistic regression was performed to assess variables influencing autograft choice in 2015-2019, presented as the odds ratio (OR) with a 95% confidence interval (CI).

RESULTS

39,964 primary ACLRs performed by 299 knee surgeons in 91 clinics were included. Most patients received HT (93.7%), followed by PT (4.2%) and QT (2.1%) grafts. Patients were mostly operated on by high-volume (> 28 ACLRs/year) surgeons (68.1%), surgeons with a caseload of ≥ 50 ACLRs (85.1%) and surgeons with the ability to use ≥ two autograft types (85.9%) (all p < 0.001). Most patients underwent ACLR at high-volume (> 55 ACLRs/year) clinics (72.2%) and at clinics capable of using ≥ two autograft types (93.1%) (both p < 0.001). Significantly increased odds of receiving PT/QT autografts were found for ACLR by surgeons with a caseload of ≥ 50 ACLRs (OR 1.41, 95% CI 1.11-1.79), but also for injury during handball (OR 1.31, 95% CI 1.02-1.67), various other pivoting sports (basketball, hockey, rugby and American football) (OR 1.59, 95% CI 1.24-2.03) and a concomitant medial collateral ligament (MCL) injury (OR 4.93, 95% CI 4.18-5.80). In contrast, female sex (OR 0.87, 95% CI 0.77-0.97), injury during floorball (OR 0.71, 95% CI 0.55-0.91) and ACLR by mid-volume relative to high-volume surgeons (OR 0.62, 95% CI 0.53-0.73) had significantly reduced odds of receiving PT/QT autografts.

CONCLUSION

An HT autograft was used in the vast majority of cases, but PT/QT autografts were used more frequently by experienced surgeons. Prior research has demonstrated significant differences in autograft characteristics. For this reason, patients might benefit if surgery is performed by more experienced surgeons.

LEVEL OF EVIDENCE

Level III.

Aerodynamic Analysis and Training Research of an S-Shaped Arc Ball Based on Hydrodynamics

The aerodynamic characteristics of S-shaped arc ball, such as poor combat performance and low intelligence, are studied and analyzed. In this paper, the aerodynamic analysis model of S-shaped arc soccer intelligent algorithm is established, and the dynamic tracking model of Soccer Tactics Based on fluid dynamics search algorithm is designed. The data information is collected from many aspects, such as the position of the players, the change of the arc ball movement, the trajectory of the football movement, and tactical flexibility. The results show that Benn's algorithm can start the layout mechanism effectively. It has high feasibility and accurate algorithm accuracy and can effectively improve the aerodynamic layout performance of the system. The aerodynamic analysis and training optimization method of the S-shaped arc ball based on ant colony optimization has sped up the intelligent training system of Chinese football tactics.

Lower rate of acceptable knee function in adolescents compared with young adults five years after acl reconstruction: results from the swedish national knee ligament register

Background

The number of studies with a large cohort of patients that primarily focus on patient-reported outcomes after ACL reconstruction in children and adolescents is limited. The purpose of the present study was to determine whether patient age affects the proportion of patients that achieve a patient-acceptable symptom state (PASS) on the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales one, two, five and 10 years after an ACL reconstruction.

Methods

The patient data in the present study were extracted from the Swedish National Knee Ligament Register (SNKLR). Patients aged between five and 35 years that underwent a primary ACL reconstruction between 1 January 2005 and 31 December 2017 and had completed the KOOS questionnaire at the one-, two-, five- or 10-year follow-up were included. A total of 2,848 patients met the inclusion criteria and were included in the study; 47 paediatric patients (females 5–13, males 5–15 years), 522 adolescents (females 14–19, males 16–19 years) and 2,279 young adults (females 20–35, males 20–35 years). The results from the KOOS were presented as the mean and 95% confidence interval (CI) for the mean. For comparisons between groups, the chi-square test was used for non-ordered categorical variables. For pairwise comparisons between groups, Fisher’s exact test (2-sided) was used for dichotomous variables. All the statistical analyses was set at 5%.

Results

Adolescents reported a significantly lower score than young adults on the KOOS4 at the two- (68.4 vs. 72.1; P < 0.05), five- (69.8 vs. 76.0; P < 0.05) and 10-year follow-ups (69.8 vs. 78.2; P < 0.05). Moreover, a significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults at the five-year follow-up (Symptoms: 83.3% vs. 91.6%; Pain: 42.9% vs. 55.3%; Function in daily living: 31.4% vs. 41.1%; Function in sports and recreational activities: 42.3% vs. 55.7%; Knee-related quality of life: 50.0% vs. 65.0%; P < 0.05).

Conclusions

A significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults five years after ACL reconstruction. The results of the present study provide important information for physicians and physiotherapists treating young patients after an ACL injury and they can aid in providing realistic expectations in terms of the mid- and long-term outcomes.

Level of evidence

Prospective Observational Register/Cohort Study, Level II.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05727-6.

Revision Rates After Primary ACL Reconstruction Performed Between 1969 and 2018: A Systematic Review and Metaregression Analysis

Background:

Numerous studies, including randomized controlled trials (RCTs), have been published on the optimal graft choice for primary anterior cruciate ligament (ACL) reconstruction.

Purpose:

To review existing studies to investigate whether advances in orthopaedics have affected revision rates after primary ACL reconstruction.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The PubMed database was searched from inception to December 31, 2020, using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Patient series, observational studies, clinical trials, and registry-based studies investigating primary ACL reconstruction were included, as were high-quality RCTs from an additional study. The minimum required follow-up time for inclusion was 1 year. The primary outcome measure was the pooled prevalence of revision ACL reconstruction. The effect of the year the surgery was performed on revision rates was evaluated with metaregression analysis. All graft types were analyzed simultaneously, and all analyses were repeated separately for each graft type.

Results:

Overall, 330 articles with 52,878 patients were included, with a median patient age of 28 years (range, 15-57 years). The primary ACL reconstructions were performed between 1969 and 2018. At a median of 2.3 years of follow-up, the overall revision rate was 3.14% (95% CI, 2.76% to 3.56%); it was 2.71% (95% CI, 2.25% to 3.27%) for hamstring autografts, 2.38% (95% CI, 1.82% to 3.11%) for bone–patellar tendon–bone (BPTB) autografts, and 5.24% (95% CI, 4.02% to 6.80%) for other graft types. For hamstring grafts, the revision rate increased over time (year of surgery), with a 0.0434 (95% CI, 0.0150 to 0.0718) increase effect in the logit-transformed scale for every additional year. There was a slight decrease in revision rates for BPTB (β = –0.0049; 95% CI, –0.0352 to 0.0254) and other graft types (β = –0.0306; 95% CI, –0.0608 to −0.0005) over time; however, confidence intervals for BPTB included the zero change.

Conclusion:

Based on this systematic review and meta-analysis, ACL reconstruction is a reliable procedure with overall low historical revision rates. BPTB autograft had the lowest revision rate and a slightly decreasing trend of failures during the past 45 years, although both BPTB and hamstring autografts are reliable graft choices.

Higher risk of ACL rupture in amateur football compared to professional football: 5-year results of the 'Anterior cruciate ligament-registry in German football'

PURPOSE

Anterior cruciate ligament (ACL) injuries are a common severe type of football injury at all levels of play. A football-specific ACL registry providing both prospective ACL injury data according to the skill level and risk factors for ACL injury is lacking in the literature.

METHODS

This study is based on the prospective 'ACL registry in German Football' implemented in the 2014-15 season. Professional (1st-3rd league), semi-professional (4th-6th league) and amateur leagues (7th league) were analysed regarding the incidence and risk factors for ACL injuries. Injuries were registered according to the direct reports of the injured players to the study office and double-checked via media analysis. After injury registration, the players received a standardised questionnaire. Data were analysed from the 2014-15 to the 2018-19 football season.

RESULTS

Overall, 958 ACL injuries were registered during the 5-year study period. The incidence of ACL injuries was highest in amateur football (0.074/1000 h football exposure) compared to professional (0.058/1000 h; p < 0.0001) and semi-professional football (0.043/1000 h; p < 0.0001). At all skill levels, match incidence (professional: 0.343; semi-professional: 0.249; amateur: 0.319) was significantly higher than training incidence (professional: 0.015; semi-professional: 0.004; amateur: 0.005). Major risk factors were previous ACL injury (mean: 23.3%), other knee injuries (mean: 19.3%) and move to a higher league (mean: 24.2%).

CONCLUSION

This sports-specific ACL registry provides detailed information on the incidence and risk factors for ACL injuries in football over five years. Risk factors are skill level, match exposure, move to a higher league and previous knee injury. These factors offer potential starting points for screening at-risk players and applying targeted prevention.

LEVEL OF EVIDENCE

II.

Risk of Graft Rupture After Adding a Lateral Extra-articular Procedure at the Time of ACL Reconstruction: A Retrospective Comparative Study of Elite Alpine Skiers From the French National Team

BACKGROUND

Elite alpine skiing is associated with a particularly high risk of anterior cruciate ligament (ACL) injuries, including graft ruptures. Despite a considerable focus on prevention, a reduction in injury rates has not been observed since the 1980s.

PURPOSE

To determine whether elite alpine skiers undergoing ACL reconstruction (ACLR) with a lateral extra-articular procedure (LEAP) had a lower rate of ACL graft rupture when compared with those who underwent isolated ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Elite skiers from the French ski team who had undergone ACLR, with or without a LEAP, and had a minimum follow-up of 2 years were identified from the national ski team database. Rates of secondary ACL injury were determined via interrogation of the database, review of medical notes, and a final telemedicine interview. A multivariable analysis using the penalized Cox model was performed to explore the relationship among graft rupture, surgical procedure type, and any potential explanatory variables.

RESULTS

Among 81 ACLR procedures analyzed, 50 were isolated and 31 were combined with a LEAP, which was performed using modified Lemaire or anterolateral ligament reconstruction. Graft rupture rates were 34.0% in the isolated ACLR group and 6.5% in the ACLR + LEAP group. Multivariable analysis demonstrated that adding a LEAP was associated with a significant reduction in risk of ACL graft rupture when compared with isolated ACLR (hazard ratio [HR], 5.286 [95% CI, 1.068-26.149]; P = .0412). Age (HR, 1.114; P = .1157), sex (HR, 1.573; P = .3743), and ACL graft type (HR, 1.417; P = .5394) were not significant risk factors.

CONCLUSION

Combined ACLR and LEAP were associated with a significant reduction in the rate of ACL graft rupture in elite alpine ski athletes. Those treated with isolated ACLR remain at extremely high risk of a second ACL injury.

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.

The Effect of Posterior Tibial Slope on the Risk of Revision Surgery After Anterior Cruciate Ligament Reconstruction

BACKGROUND

A significant proportion of patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) later experience graft failure. Some studies suggest an association between a steep posterior tibial slope (PTS) and graft failure.

PURPOSE

To examine the PTS in a large cohort of patients about to undergo ACLR and to determine whether a steep PTS is associated with later revision surgery.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A retrospective review of a cohort undergoing isolated ACLR between 2002 and 2012 (with 8-19 years of follow-up) was conducted. Preoperative sagittal radiographs of knees in full extension were used for measurements of the PTS. There were 2 independent examiners who performed repeated measurements to assess the reliability of the method. Statistical analyses were performed to compare the PTS in the groups with and without later revision surgery.

RESULTS

A total of 728 patients, with a mean age of 28 years at the time of surgery, were included. Overall, 10% (n = 76) underwent revision surgery during the observation period. The group of injured knees had a significantly steeper PTS compared with the group of uninjured knees (9.5° vs 8.7°, respectively; P < .05). The mean PTS in the no revision group was 9.5° compared with 9.3° in the revision group (not significant). Dichotomized testing of revision rates related to PTS cutoff values of ≥10°, ≥12°, ≥14°, ≥16°, and ≥18° showed no association of PTS steepness (not significant) to graft failure. Patients with revision were younger than the ones without (mean age, 24 ± 8 vs 29 ± 10 years, respectively) and had a shorter time from injury to ACLR (mean, 14 ± 27 vs 24 ± 44 months, respectively) as well as a smaller graft size (8.2 vs 8.4 mm, respectively; P = .040).

CONCLUSION

The current study did not find any association between a steep PTS measured on lateral knee radiographs and revision ACL surgery. However, a steeper PTS was seen in the group of injured knees compared with the group of uninjured (contralateral) knees. Independent of the PTS, younger patients, those with a shorter time from injury to surgery, and those with a smaller graft size were found to undergo revision surgery more often.

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).

Contralateral ACL tears strongly contribute to high rates of secondary ACL injuries in professional ski racers

PURPOSE

To analyse the effects of graft selection, sex, injury complexity and time to return to competition on the odds to suffer secondary ACL injury (either re-rupture or contralateral ACL tear) in professional alpine skiers.

METHODS

The database of a specialised joint surgery clinic was screened for professional alpine skiers who had participated in competitions at the FIS race, European Cup and World Cup level prior to having to undergo a primary ACL reconstruction, and who had returned to the same competitional level at least one year prior to the end of the observation period. The rates of secondary ACL injuries were statistically compared between athletes with hamstring and quadriceps tendon autografts, men and women, simple and complex (involvement of menisci or cartilage) primary ACL injuries, and between early (≤ 300 days after primary reconstruction) and late (> 300 days) returners to competition.

RESULTS

Fourteen out of the 30 athletes included (46.7%) suffered secondary ACL injuries on average 29.4 ± 22.5 months after primary reconstruction. The secondary injuries comprised five re-ruptures (16.7%) and nine contralateral ACL tears (30.0%). The odds to suffer contralateral ACL tears were non-significantly higher in patients with hamstring tendon autografts (OR 5.69, n.s.) and in those whose primary injuries were classified as simple ACL tears (OR 5.31, n.s.). None of the factors assessed was associated with the odds of graft failure.

CONCLUSION

The odds of ACL-injured professional alpine ski racers to suffer secondary ACL tears are nearly 50%, with subsequent contralateral ACL injuries being more common than graft failures. While statistical significance could not be established due to a lack of power, greater odds of contralateral ACL tears were observed in athletes with hamstring tendon grafts as well as those with simple primary ACL injuries. No factors potentially predisposing athletes for graft failure could be identified.

LEVEL OF EVIDENCE

III.

Does sex affect second ACL injury risk? A systematic review with meta-analysis

OBJECTIVE

To determine sex-based differences in risk of a second ACL injury (overall and by laterality) following primary ACL reconstruction in athletes who are attempting to return to sport.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Systematic search of five databases conducted in August 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies reporting sex-based differences in the incidence of second ACL injury in athletes attempting to return-to-sports and who were followed for at least 1 year following primary ACL reconstruction.

RESULTS

Nineteen studies were included in this review, with seven studies excluded from the primary meta-analysis due to high risk of bias. The remaining 12 studies (n=1431 females, n=1513 males) underwent meta-analysis, with all 19 studies included in a sensitivity analysis. Total second ACL injury risk was 21.9% (females: 22.8%, males: 20.3%). Females were found to have 10.7% risk of an ipsilateral ACL injury and 11.8% risk of a contralateral ACL injury. Males were found to have 12.0% risk of an ipsilateral ACL injury and 8.7% risk of a contralateral ACL injury. No statistically significant differences were observed for total second ACL injury risk (risk difference=-0.6%, 95% CI -4.9 to 3.7, p=0.783, I²=41%) or contralateral ACL injury risk (risk difference=1.9%, 95% CI -0.5% to 4.4%, p=0.113, I²=15%) between sexes. Females were found to have a 3.4% absolute risk reduction in subsequent ipsilateral ACL injury risk compared with males (risk difference=-3.4%, 95% CI -6.7% to -0.02%, p=0.037, I²=35%).

CONCLUSION

Both sexes have >20% increased risk of experiencing a second ACL injury. Any difference in the absolute risk of either a subsequent ipsilateral or contralateral ACL injury between sexes appears to be small.

REGISTRATION

PROSPERO (CRD42020148369).

Hamstrings substitution via anteromedial portal with optional anterolateral ligament reconstruction is the preferred surgical technique for anterior cruciate ligament reconstruction: a survey among ESSKA members

PURPOSE

The objective of this study was to report on a worldwide web-based survey among the ESSKA community developed to investigate current recommendations regarding ACL reconstruction surgical procedures.

METHODS

All contacts in the official mailing list of the ESSKA were contacted to investigate preferences regarding graft type, anterolateral ligament reconstruction, femoral tunnel drilling technique, single-bundle vs double-bundle technique, femoral and tibial fixation methods.

RESULTS

Eight-hundred and twenty responses were analyzed. Hamstrings autograft was the graft of choice in male patients for 634 (79%) and in female patients for 674 (84%) responders, while its preference for ACL reconstruction in professional athletes was for 401 (50%). 480 (63%) surgeons surveyed would include anterolateral ligament reconstruction only if diagnosed and remaining instability after ACL surgery or revision. 598 (75%) respondents were in favor of anteromedial portal for femoral tunnel drilling. The most popular femoral fixation technique was found to be cortical suspension (500-66%), while a compression system was preferred on the tibial side by 537 (71% of the sample).

CONCLUSIONS

This survey study found that HT autograft, single-bundle reconstruction, anteromedial portal for femoral tunnel drilling, cortical suspension systems for femoral fixation and compression systems for tibial fixation represent the current standard of ACLR in a large community of orthopedic surgeons. The present study performed with surgeons who are members of the ESSKA community will help to comprehend the actual ACLR worldwide practice patterns. Due to low response rate, these results should be interpreted with caution and not to be intended to represent the state of the art of ESSKA community.

LEVEL OF EVIDENCE

III.

Intensive supervised rehabilitation versus less supervised rehabilitation following anterior cruciate ligament reconstruction? A systematic review and meta-analysis

OBJECTIVES

To investigate whether intensive supervised rehabilitation following ACL reconstruction leads to superior self-reported function and sports participation compared to less supervised rehabilitation.

DESIGN

Systematic review and meta-analysis.

METHODS

We included randomised controlled trials (RCTs) comparing supervised rehabilitation to rehabilitation with a similar protocol that used less supervised sessions for athletes following ACL reconstruction. Two reviewers independently screened studies and extracted data. The Physiotherapy Evidence Database (PEDro) scale was used to evaluate methodological quality and GRADE to evaluate overall quality of evidence. Self-reported function and sports participation were the primary outcomes. Data were pooled using random effects meta-analyses.

RESULTS

Our search retrieved 4075 articles. Seven articles reporting on six RCTs were included (n=353). Very-low to low-certainty evidence suggests intensive supervised rehabilitation is not superior to less supervised rehabilitation following ACL reconstruction for improving self-reported function, sports participation, knee flexor and extensor strength, range of motion, sagittal plane knee laxity, single leg hop performance, or quality of life.

CONCLUSION

Based on uncertain evidence, intensive supervised rehabilitation is not superior to less supervised rehabilitation for athletes following ACL reconstruction. Although high-quality RCTs are needed to provide more certain evidence, clinicians should engage athletes in shared decision making to ensure athletes' rehabilitation decisions align with current evidence on supervised rehabilitation as well as their preferences and values.

Effectiveness of thicker hamstring or patella tendon grafts to reduce graft failure rate in anterior cruciate ligament reconstruction in young patients

PURPOSE

The purpose of this study was to determine the anterior cruciate ligament reconstruction (ACLR) failure rate in young patients utilizing the New Zealand (NZ) anterior cruciate ligament (ACL) Registry. The hypothesis was that the ACLR rupture rate would be lower for thicker hamstring graft and bone patellar tendon bone (BPB) grafts in comparison to the classic hamstring technique. The ACLR failure rate was assessed according to graft type and patients' sex.

METHODS

The NZ ACL registry was utilized to identify all patients aged 20 years or younger at the time of surgery who were skeletally mature and had a minimum 2-year follow-up. Graft ruptures, defined as an ACL revision, were identified according to graft type (traditional 4 strands hamstring semitendinosus and gracilis, 4 strands semitendinosus, 5-6 strands semitendinosus and gracilis, 7-8 strands semitendinosus and gracilis, bone-patella-bone graft).

RESULTS

Nine-hundred and ninety-two patients were included. At a mean follow-up of 38 months, 52 cases of graft rupture were recorded, (overall failure rate: 5.2%). The failure rate was not statistically influenced by the graft diameter. Patients with a thinner graft (< 8 mm-196 patients) had a similar failure rate (6%) to patients with a thicker graft (8 mm or more-485 patients) (6.2%). There was a lower failure rate in the BPB group (3.1%) versus all hamstrings group (6%) (ns). Finally, BPB in females had a lower failure rate than all hamstring constructs together (0% versus 5.1%; p = 0.023) CONCLUSION: In a young population traditional four-strand hamstring grafts, multiple strand configurations or BPB ACLR, whatever their size (> or < 8 mm), showed no significant difference in the failure rate in the NZ ACL registry. Female patients who had an ACL reconstruction with BPB graft had a significant lower failure rate than patients who had a hamstring graft.

LEVEL OF EVIDENCE

III.

Fibroblasts From Common Anterior Cruciate Ligament Tendon Grafts Exhibit Different Biologic Responses to Mechanical Strain

BACKGROUND

Different tendons are chosen for anterior cruciate ligament (ACL) reconstruction based on perceived advantages and disadvantages, yet there is a relative paucity of information regarding biologic responsiveness of commonly used tendon grafts to mechanical strain.

PURPOSE

To evaluate the in vitro responses of graft fibroblasts derived from tendons used for ACL reconstruction to clinically relevant strain levels.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve quadriceps tendons (QTs), 12 patellar tendons (PTs), and 9 hamstring tendons (HTs) were harvested from skeletally mature dogs (n = 16). Tendon fibroblasts were isolated and seeded onto BioFlex plates (1 × 10⁵ cells/well). Cells were subjected to 3 strain conditions (stress deprivation, 0%; physiologic, 4%; high, 10%) for 5 days. Media were collected for proinflammatory and metabolic assays. RNA was extracted for gene expression analysis using real-time reverse transcription polymerase chain reaction.

RESULTS

Stress deprivation elicited significantly higher metabolic activity from HT and PT cells than from QT cells (P < .001 and P = .001, respectively). There were no differences in metabolic activity among all 3 graft fibroblasts at physiologic and high strain. COL-1 expression was significantly higher in PT versus HT during physiologic strain (P = .007). No significant differences with COL-3 expression were seen. TIMP-1 (P = .01) expression was higher in PT versus HT under physiologic strain. Scleraxis expression was higher in PT versus HT (P = .007) under physiologic strain. A strain-dependent increase in PGE2 levels occurred for all grafts. At physiologic strain conditions, HT produced significantly higher levels of PGE2 versus QT (P < .001) and PT (P = .005).

CONCLUSION

Fibroblasts from common ACL graft tissues exhibited different metabolic responses to mechanical strain. On the basis of these data, we conclude that early production of extracellular matrix and proinflammatory responses from ACL grafts are dependent on mechanical loading and graft source.

CLINICAL RELEVANCE

Graft-specific differences in ACL reconstruction outcomes are known to exist. Our results suggest that there are differences in the biologic responsiveness of cells from the tendon grafts used in ACL reconstruction, which are dependent on strain levels and graft source. The biologic properties of the tissue used for ACL reconstruction should be considered when selecting graft source.