A meta-analysis of stability after anterior cruciate ligament reconstruction as a function of hamstring versus patellar tendon graft and fixation type

Lateral Extra-Articular Tenodesis and Anterolateral Procedures

The treatment of rotational instability has been an intriguing challenge since the era of modern anterior cruciate ligament (ACL) surgery. Lateral extra-articular procedures (LEAPs) have emerged as a solution to this problem, particularly in high-risk populations. Several studies have shown significant benefits of combining LEAPs with ACL reconstruction, including reduced graft failure rates, improved knee stability, improved rotational stability, and higher return-to-play rates. These findings have led to an in-depth evaluation of LEAPs as lateral extra-articular tenodesis and anterolateral ligament reconstruction and their potential role in improving outcomes after ACL reconstruction.

Evaluation of Failed ACL Reconstruction: An Updated Review

Failure rates among primary Anterior Cruciate Ligament Reconstruction (ACLR) range from 3.2% to 11.1%. Recently, there has been increased focus on surgical and anatomic considerations which predispose patients to failure, including excessive posterior tibial slope (PTS), unaddressed high-grade pivot shift, and improper tunnel placement. The purpose of this review was to provide a current summary and analysis of the literature regarding patient-related and technical factors surrounding revision ACLR, rehabilitation considerations, overall outcomes and return to sport (RTS) for patients who undergo revision ACLR. There is a convincingly higher re-tear and revision rate in patients who undergo ACLR with allograft than autograft, especially amongst the young, athletic population. Unrecognized Posterior Cruciate Ligament (PLC) injury is a common cause of ACLR failure and current literature suggests concurrent operative management of high-grade PLC injuries. Given the high rates of revision surgery in young active patients who return to pivoting sports, the authors recommend strong consideration of a combined ACLR + Anterolateral Ligament (ALL) or Lateral extra-articular tenodesis (LET) procedure in this population. Excessive PTS has been identified as an independent risk factor for ACL graft failure. Careful consideration of patient-specific factors such as age and activity level may influence the success of ACL reconstruction. Additional technical considerations including graft choice and fixation method, tunnel position, evaluation of concomitant posterolateral corner and high-grade pivot shift injuries, and the role of excessive posterior tibial slope may play a significant role in preventing failure.

Why Your Patient May Need an ACL Reconstruction Plus Lateral Extra-Articular Tenodesis Procedure

Anterior cruciate ligament (ACL) tears are one of the most common knee injuries experienced by active individuals engaging in cutting sports. Despite improved surgical techniques and rehabilitation, the return to sport rate and re-tear rates remain unsatisfactory. Lateral extra-articular tenodesis (LET) is a procedure that has been growing in interest when performed in conjunction with ACL reconstruction. The benefits of adding an LET procedure to an ACL surgery may include greater rotational stability, decreased re-tear rates, and improved return to play. Level of evidence: V.

Evaluating the quality of systematic reviews of comparative studies in autograft-based anterior cruciate ligament reconstruction using the AMSTAR-2 tool: A systematic umbrella review

PURPOSE

There remains a lack of consensus around autograft selection in anterior cruciate ligament reconstruction (ACLR), though there is a large body of overlapping systematic reviews and meta-analyses. Systematic reviews and their methodological quality were aimed to be further assessed, using a validated tool known as assessing the methodological quality of systematic reviews (AMSTAR-2).

METHODS

MEDLINE, Embase and CENTRAL were searched from inception to 23 April 2023 for systematic reviews (with/without meta-analysis) comparing primary ACLR autografts. A final quality rating from AMSTAR-2 was provided for each study ('critically low', 'low', 'moderate' or 'high' quality). Correlational analyses were conducted for ratings in relation to study characteristics.

RESULTS

Two thousand five hundred and ninety-eight studies were screened, and 50 studies were ultimately included. Twenty-four studies (48%) were rated as 'critically low', 17 (34%) as 'low', seven (14%) as 'moderate' and two (4%) as 'high' quality. The least followed domains were reporting on sources of funding (1/50 studies), the impact of risk of bias on results of meta-analyses (11/36 studies) and publication bias (17/36 studies). There was a significant increase in the frequency of studies graded as 'moderate' compared to 'low' or 'critically low' quality over time (p = 0.020).

CONCLUSION

The methodological quality of systematic reviews comparing autografts in ACLR is low, with many studies being rated lower due to commonly absent aspects of systematic review methodology such as investigating sources of funding and publication bias. More recent studies were generally more likely to be of higher quality. Authors are advised to consult AMSTAR-2 prior to conducting systematic reviews in ACLR.

LEVEL OF EVIDENCE

Level IV.

Must a Knee with Anterior Cruciate Ligament Deficiency and High-grade Pivot Shift Test Present an Increase in Internal Rotation?

Objective:  Rupture of the anterior cruciate ligament (ACL) is one of the most common injuries in athletes and is often associated with damage to anterolateral structures. This combination of injuries presents itself clinically as a high-grade pivot shift test. The hypothesis of this study is that patients with ACL deficiency and high-grade pivot shift test should have an increased internal knee rotation. Methods:  Twenty-two patients were tested. After effective spinal anesthesia, two tests were performed with the patient in supine position. First, the bilateral pivot shift test was performed manually, and its grade was recorded. Then, with the knee flexed to 90 degrees, the examiner drew the projection of the foot in a neutral position and in maximum internal rotation, and the angle of internal rotation was measured from the axes built between the central point of the heel and the hallux. Results:  In the ACL-deficient knee, it was observed that there is a statistically significant average internal rotation (IR) delta of 10.5 degrees between the groups when not adjusted for age, and 10.6 degrees when adjusted for age. Conclusions:  Knees with ACL deficiency and with pivot shift test grade I do not show increased internal rotation in relation to knees with intact ACL. Knees with ACL deficiency and with pivot shift test grades II and III show increased internal rotation in comparison to healthy knees.

Metal interference screw fixation combinations show high revision rates in primary hamstring tendon ACL reconstruction

BACKGROUND

Different fixation methods in anterior cruciate ligament reconstruction (ACLR) have been associated with different revision rates, specifically in the early postoperative period. However, most previous research has either grouped together different fixation types or evaluated femoral-sided fixation or tibial-sided fixation separately. Therefore, the purpose of this study was to determine ACL revision rates for specific combinations of femoral and tibial fixation methods within 2 years of primary hamstring tendon autograft ACLR based on data from the Swedish National Knee Ligament Registry (SNKLR).

METHODS

Patients that underwent primary hamstring tendon autograft ACLR between 2005 and 2018 in the SNKLR were included. The collected data included patient characteristics (age, sex, body mass index [BMI]), activity at time of injury, surgical information (concomitant injuries, time from injury to surgery, fixation types at the femur and tibia), and subsequent revision ACLR. Revision rate within 2 years of the index procedure was chosen, as ACLR fixation is most likely to contribute to ACLR revision within the first 2 years, during graft maturation.

RESULTS

Of the 23,238 included patients undergoing primary hamstring ACLR, 581 (2.5%) underwent revision ACLR within 2 years of the index procedure. Among the combinations used for > 300 patients, the femoral metal interference screw/tibial metal interference screw fixation combination had the highest revision rate followed by metal interference screw/resorbable screw and Endobutton/AO screw fixation combinations, with respective revision rates of 4.0, 3.0, and 3.0%. The lowest revision rate within 2 years of ACLR was found in the Endobutton/metal interference screw with backup Osteosuture fixation combination, used in 433 cases, with a failure rate of 0.9%.

CONCLUSION

Different early ACL revision rates were found across different combinations of femoral and tibial fixation devices within 2 years of primary hamstring tendon autograft ACLR. Metal interference screw fixation, particularly when performed on both the femoral and tibial sides, most frequently resulted in revision ACLR. These findings may be helpful for surgeons in selecting appropriate fixation devices for hamstring ACLR.

LEVEL OF EVIDENCE

IV.

Patient Decision Making in Anterior Cruciate Ligament Reconstruction: A Discrete Choice Experiment Examining Graft Preference

Background

Bone-patellar tendon-bone (BTB) and hamstring autografts are the most common grafts used for anterior cruciate ligament (ACL) reconstruction. Patient preferences should be accounted for as a part of shared decision making.

Purpose/Hypothesis

The purpose of this study was to perform a discrete choice experiment that evaluated patient preferences toward ACL autografts. We hypothesized that there would be no difference in patient preferences between groups.

Study Design

Cross-sectional study.

Methods

Patients aged 18 to 25 years who underwent shoulder arthroscopy at a single institution between 2013 and 2019 were included in the study as a proxy for healthy controls. Patients with a history of ACL tear were excluded. A discrete choice experiment was developed from a literature search and used the following data points as they pertain to BTB or hamstring autograft: risk of developing a significant complication, return-to-play rate, risk of anterior knee pain with kneeling, and risk of additional surgery due to graft failure. Included patients completed a custom survey in which they were asked to choose between "surgery A" (hamstring) and "surgery B" (BTB).

Results

A total of 107 participants were included in the analysis. Of these participants, 39 (36.5%) chose surgery A (hamstring) and 68 (63.6%) chose surgery B (BTB). When comparing the hamstring group with the BTB group, there was no significant difference in age, sex, body mass index, race, level of education, or employment status. However, 80.5% of self-reported athletes preferred BTB (P = .008). When controlling for age, sex, and body mass index, patients in the BTB group were more likely to rate return to sport (risk ratio [RR] = 1.49 [95% CI, 1.18-1.98]; P = .001) and the risk of requiring additional surgery due to graft failure (RR = 1.26 [95% CI, 1.02-1.58]; P = .037) as highly important. Conversely, they were less likely than patients in the hamstring group to rate pain while kneeling (RR = 0.65 [95% CI, 0.98-1.05]; P < .001) and complication risk (RR = 0.75 [95% CI, 0.59-0.94]; P = .013) as important.

Conclusion

The study hypothesis was rejected, as patient values did affect ACL graft choice preference. Utilizing patient-selected values in a quantifiable way can benefit the shared decision-making process before ACL reconstruction.

Graft choices for anterolateral ligament knee reconstruction surgery: Current concepts

The anterolateral ligament (ALL) is a primary structure of the anterolateral complex of the knee that contributes to internal rotational stability of the joint. Injury of the ALL is commonly associated with rupture of the anterior cruciate ligament. If left untreated, ALL lesions may lead to residual anterolateral rotational instability of the knee after anterior cruciate ligament reconstruction, which is a common cause of anterior cruciate ligament graft failure. The function of the ALL can be restored by lateral extraarticular tenodesis or anterolateral ligament reconstruction (ALLR). In the lateral extraarticular tenodesis procedure, a strip of the iliotibial band is placed in a non-anatomical position to restrain the internal rotation of the tibia, while in ALLR, a free graft is fixed at the insertion points of the native ALL. Gracilis and semitendinosus grafts have mainly been utilized for ALLR, but other autografts have also been suggested. Furthermore, allografts and synthetic grafts have been applied to minimize donor-site morbidity and maximize the size and strength of the graft. Nevertheless, there has been no strong evidence to fully support one method over another thus far. The present review presents a detailed description of the graft choices for ALLR and the current literature available in regard to the effectiveness and outcomes of published surgical techniques.

The effect of lateral extra-articular tenodesis on in vivo cartilage contact in combined anterior cruciate ligament reconstruction

PURPOSE

Lateral extra-articular tenodesis (LET) may confer improved rotational stability after anterior cruciate ligament reconstruction (ACLR). Little is known about how LET affects in vivo cartilage contact after ACLR. The aim of this study was to investigate the effect of LET in combination with ACLR (ACLR + LET) on in vivo cartilage contact kinematics compared to isolated ACLR (ACLR) during downhill running. It was hypothesised that cartilage contact area in the lateral compartment would be larger in ACLR + LET compared with ACLR, and that the anterior-posterior (A-P) position of the contact center on the lateral tibia would be more anterior after ACLR + LET than after ACLR.

METHODS

Twenty patients were randomly assigned into ACLR + LET or ACLR during surgery (ClinicalTrials.gov:NCT02913404). At 6 months and 12 months after surgery, participants were imaged during downhill running using biplane radiography. Tibiofemoral motion was tracked using a validated registration process. Patient-specific cartilage models, obtained from 3 T MRI, were registered to track bone models and used to calculate the dynamic cartilage contact area and center of cartilage contact in both the medial and lateral tibiofemoral compartments, respectively. The side-to-side differences (SSD) were compared between groups using a Mann-Whitney U test.

RESULTS

At 6 months after surgery, the SSD in A-P cartilage contact center in ACLR + LET (3.9 ± 2.6 mm, 4.4 ± 3.1 mm) was larger than in ACLR (1.2 ± 1.6 mm, 1.5 ± 2.0 mm) at 10% and 20% of the gait cycle, respectively (p < 0.01, p < 0.05). There was no difference in the SSD in cartilage contact center at 12 months after surgery. There was no difference in SSD of cartilage contact area in the medial and lateral compartments at both 6 and 12 months after surgery. There were no adverse events during the trial.

CONCLUSION

LET in combination with ACLR may affect the cartilage contact center during downhill running in the early post-operation phase, but this effect is lost in the longer term. This suggests that healing and neuromuscular adaptation occur over time and may also indicate a dampening of the effect of LET over time. (337 /350 words) LEVEL OF EVIDENCE: Level II.

Comparison of Bone-Patella Tendon-Bone and Four-Strand Hamstring Tendon Grafts for Anterior Cruciate Ligament Reconstruction: A Prospective Study

Introduction

To date, the proper choice of graft for anterior cruciate ligament (ACL) reconstruction remains a matter of conflict. We aimed to compare the clinical and functional outcomes of the two most commonly utilized autografts, bone-patella tendon-bone (BPTB) and four-strand hamstring tendon (HT) graft, at 6 and 12 months after surgery.

Methods

In a prospective randomized study, we included a total of 60 patients undergoing ACL reconstruction, thirty in BPTB and thirty in HT group. All patients were amateur athletes and were evaluated at 6 and12 months after surgery for: (a)postoperativefunctionality of the operated knee by the Tegner, the Lysholm and the International Knee Documentation Committee (IKDC) scoring scales, (b) anterior cruciate ligament (ACL) instability of the operated knee compared to the healthy contralateral knee by the KT-1000 arthrometer and (c) theextension and flexion muscle strength of the operated knee by a CYBEXisokinetic dynamometer. 

Results

Patients in the two groups did not differ regarding demographics, and pre-injury functionality status. Significantly more patients in the HT group (n=6) compared to the BPTB group (n=1) experienced ACL re-rupture and underwent revision surgery before follow-up end (p=0.044). All patients, regardless of graft, showed significant improvement within each group of functional assessments by Lysholm, Tegner and IKDC scores, as well as of Cybex measurements -with an increase of peak torque at 60° extension and 180°extension and 60° flexion and 180° flexion- at 12 months compared to 6 months follow-up (p<0.05). However, there was no difference between the two groups regarding knee function improvement or extension measurements neither at 6 nor 12 months. Contrarily, the BPTB graft group had higher values of peak torque (Nm) at 60° and 180° flexion compared to the HT group, both at 6 (p=0.014 and 0.029, respectively) and 12 months (p=0.033 and 0.030, respectively). Postoperative stability was similar between the two groups at 12 months (p=0.519).

Conclusion

Both BPTB and HT grafts present with benefits and drawbacks and remain viable autograft options for primary ACL reconstruction as each has, although HT grafts seem to be more susceptible to re-rupture. The graft selection should be based on the needs and activities of each patient. 

A Systematic Approach for Stronger Documentation of Anterior Cruciate Ligament Graft Choice

Numerous studies have focused on determining the optimal choice between the two most used anterior cruciate ligament (ACL) reconstruction autografts. In order to address this matter, we performed a systematic review of every meta-analysis published on the PubMed platform between 2001 and 2020, comparing the functional outcomes, the static stability parameters, as well as the postoperative and long-term complications of the patellar tendon (BPTB) autograft and hamstrings (HT). We retrieved a total of 26 meta-analyses that met our criteria, and the characteristics and outcomes of every meta-analysis, as well as subgroup analysis regarding the type of the study design, number of strands of HT autograft, and fixation method, were extensively recorded. The majority of the meta-analyses showed that there were no significant differences between BPTB and HT in terms of functional outcomes and static stability parameters while HT autografts seem to be superior to BPTB regarding kneeling pain and anterior knee pain. Other outcomes seem to be affected by the number of strands of the HT autograft, the fixation technique, and the type of study design, indicating superiority of the four-strand HT autograft with the use of an extra-cortical button fixation. Overall, there is no clear superiority of BPTB over HT autografts for ACL reconstruction, as both types present similar outcomes in the majority of postoperative parameters. Autograft selection should be individualized according to each patient's needs and more RCTs are warranted in order to reach safer results on the appropriate autograft type.

Effect of Modified Lemaire Anterolateral Extra-articular Tenodesis on the Magnetic Resonance Imaging Maturity Signal of Anterior Cruciate Ligament Hamstring Graft

BACKGROUND

Lateral extra-articular tenodesis (LET) is one of the most widely used procedures to restore anterolateral stability. Clinical outcomes after the addition of LET to anterior cruciate ligament (ACL) reconstruction (ACLR) have been widely investigated; however, the potential influence of LET on the ACL ligamentization process has not been examined.

PURPOSE/HYPOTHESIS

The purpose was to use 10-month postoperative magnetic resonance imaging (MRI) scans to determine whether the maturity of grafts after hamstring autograft ACLR was affected by concomitant LET. The hypothesis was that when modified Lemaire lateral extra-articular tenodesis (MLLET) was performed, the MRI parameters of ACL graft maturity would be modified.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The study included patients treated between December 2017 and December 2018 who had undergone anatomic 3-strand hamstring tendon autograft ACLR, with or without concomitant MLLET, and had undergone MRI 10 months postoperatively. Thus, the study included 30 patients who had isolated ACLR and 22 patients who had ACLR plus MLLET. The 2 groups were comparable based on all criteria analyzed. To evaluate graft maturity, the signal-to-noise quotient (SNQ) was measured in 3 regions of interest of the proximal, midsubstance, and distal ACL graft. Lower SNQ ratios indicate less water content and, theoretically, better maturity and healing of the graft.

RESULTS

The mean ± SD for SNQ was 4.62 ± 4.29 (range, 3.12-6.19) in the isolated ACLR group and 7.59 ± 4.68 (range, 4.38-8.04) in the ACLR plus MLLET group (P = .012). Upon comparing the mean values of the 3 portions between the 2 groups, we found a significant difference between the 2 groups for the proximal and middle portions (P = .007 and P = .049, respectively) but no difference in the distal portion (P = .369).

CONCLUSION

At the 10-month follow-up, hamstring tendon autografts for anatomic ACLR with MLLET did not show the same MRI signal intensity compared with isolated hamstring anatomic ACLR.

Validation of a Risk Calculator to Personalize Graft Choice and Reduce Rupture Rates for Anterior Cruciate Ligament Reconstruction

BACKGROUND

Anterior cruciate ligament reconstructions (ACLRs) fail at an alarmingly high rate in young active individuals. The Multicenter Orthopaedic Outcomes Network (MOON) knee group has developed an autograft risk calculator that uses patient characteristics and lifestyle to predict the probability of graft rupture if the surgeon uses a hamstring tendon (HT) or a bone-patellar tendon-bone (BPTB) graft to reconstruct the ligament. If validated, this risk calculator can be used during the shared decision-making process to make optimal ACLR autograft choices and reduce rupture rates. The STABILITY 1 randomized clinical trial offers a large, rigorously collected data set of similar young active patients who received HT autograft with or without lateral extra-articular tenodesis (LET) for ACLR.

PURPOSE/HYPOTHESIS

The purpose was to validate the ACLR graft rupture risk calculator in a large external data set and to investigate the utility of BPTB and LET for ACLR. We hypothesized that the risk calculator would maintain adequate discriminative ability and calibration in the external STABILITY 1 data set when compared with the initial MOON development data set.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 1.

METHODS

The model predictors for the risk calculator include age, sex, body mass index, sport played at the time of injury, Marx Activity Score, preoperative knee laxity, and graft type. The STABILITY 1 trial data set was used for external validation. Discriminative ability, calibration, and diagnostic test validity of the model were assessed. Finally, predictor strength in the initial and validation samples was compared.

RESULTS

The model showed acceptable discriminative ability (area under the curve = 0.73), calibration (Brier score = 0.07), and specificity (85.3%) to detect patients who will experience a graft rupture. Age, high-grade preoperative knee laxity, and graft type were significant predictors of graft rupture in young active patients. BPTB and the addition of LET to HT were protective against graft rupture versus HT autograft alone.

CONCLUSION

The MOON risk calculator is a valid predictor of ACLR graft rupture and is appropriate for clinical practice. This study provides evidence supporting the idea that isolated HT autografts should be avoided for young active patients undergoing ACLR.

REGISTRATION

NCT00463099 (MOON); NCT02018354 (STABILITY 1) (ClinicalTrials.gov identifiers).

Outcome of bone-patellar tendon-bone vs hamstring tendon autograft for anterior cruciate ligament reconstruction: A meta-analysis of randomized controlled trials with a 5-year minimum follow-up

BACKGROUND

Many systematic reviews have compared the short-term outcomes of anterior cruciate ligment (ACL)reconstruction with hamstring and patellar tendon autograft,but few differences have been observed. The purpose of this meta-analysis was to compare the medium-term outcome of bone-patellar tendon-bone and hamstring tendon autograft for anterior cruciate ligament reconstruction in terms of clinical function, knee stability, postoperativecomplications, and osteoarthritis changes.

METHODS

This meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed, Embase, and the Cochrane Library databases were searched from inception to November 2, 2019. This meta-analysis included only randomized controlled trials that compared BPTB and HT autografts for ACL reconstruction with a 5-year minimum follow-up. The Cochrane Collaboration's risk-of-bias tool was used to estimate the risk-of-bias for all included studies. RevMan 5.3 software was used to performed statistical analysis of the outcomes.

RESULTS

Fifteen RCTs, involving 1298 patients (610 patients in the BPTB group and 688 patients in the HT group) were included. In terms of clinical function, no significant difference was found in the objective International Knee Documentation Committee score (OR = 0.94, 95%CI: 0.64-1.37, P = .75), Lysholm knee score (MD = -2.26, 95%CI: -4.56 to 0.05, P = .06), return to preinjury activity level (OR = 1.01, 95%CI: 0.67-1.52, P = .96), and Tegner activity level (OR = 0.03, 95%CI: -0.36 to 0.41, P = .89). There was no statistically significant difference in the Lachman test (OR = 0.86, 95%CI: 0.5-1.32, P = .50), pivot-shift test (OR = 0.68, 95%CI: 0.44-1.06, P = .09), and side-to-side difference (MD = -0.32, 95%CI: -0.81 to 0.16, P = .19). As for postoperative complications and OA changes, there were no statistically significant difference in flexion loss (OR = 1.09, 95%CI: 0.47-2.54, P = .85) and OA changes (OR = 0.76, 95%CI: 0.52-1.10, P = .15), but we found significant differences in favor of the HT group in the domains of kneeling pain (OR = 1.67, 95%CI: 1.04-2.69, P = .03), anterior knee pain (OR = 2.90, 95%CI: 1.46-5.77, P = .002), and extension loss (OR = 1.75, 95%CI: 1.12-2.75, P = .01). There was a significant difference in favor of the BPTB group in the domain of graft failure (OR = 0.59, 95%CI: 0.38-0.91, P = .02).

CONCLUSIONS

Based on the results above, HT autograft is comparable with the BPTB autograft in terms of clinical function, postoperative knee stability, and OA changes, with a medium-term follow-up. The HT autograft for ACL reconstruction carries a lower risk of complications, such as anterior knee pain, kneeling pain, and extension loss, but an increased incidence of graft failure. Patients should be informed of the differences when deciding on graft choice with their physician.

Clinical Outcomes of the Central Third Patellar Tendon Versus Four-strand Hamstring Tendon Autograft Used for Anterior Cruciate Ligament Reconstruction: A Systematic Review and Subgroup Meta-analysis of Randomized Controlled Trials

BACKGROUND

The most frequently used auto-grafts for ACL reconstruction (ACLR) are bone-patellar tendon-bone (BPTB) and four-strand hamstring tendon (4S-HT), but significant controversy exists about which graft is better. This study aimed to compare the knee outcomes following ACLR with BPTB and 4S-HT autografts.

METHODS

Subgroup meta-analyses were performed basing on available randomised controlled trials (RCTs) according to different follow-up intervals. 23 RCTs were eligible for inclusion, involving 933 participants in each treatment group.

RESULTS

Only short-term (≤2 years) knee anteroposterior and rotational stability were significantly poorer with 4S-HT when compared to BPTB autograft, as judged by side-to-side difference on knee laxity (WMD=-0.50, 95%CI -0.81~-0.18, p=0.002) and pivot-shift test (OR=0.58, 95%CI 0.39~0.88, p=0.010), respectively. The IKDC objective grade was evident to be in favour of 4S-HT group in mid-term (3-5 years) follow-up (OR=0.63, 95%CI 0.43~0.92, p=0.017). Several donor-site related complications, including anterior knee pain, pain with kneeling and extension deficit, were more frequent in BPTB autograft group, while lower short-term iskinetic peak flexion torques both at 60°/S (WMD=8.93, 95%CI 7.88~9.99, p<0.001) and 240°/S (WMD=11.63, 95%CI 9.92~13.34, p<0.001) were caused by HT harvesting.

CONCLUSION

BPTB was associated with inferior mid- to long-term (>5 years) knee functional outcomes, and increased frequency of donor-site complications. In contrast, only short-term knee laxity was increased for 4S-HT autograft, which is expected to be improved by providing more conservative rehabilitation protocol and aperture fixation methods.

Aperture and Suspensory Fixation Equally Efficacious for Quadriceps Tendon Graft Fixation in Primary ACL Reconstruction: A Systematic Review

This review is aimed to compare suspensory and aperture quadriceps tendon autograft femoral and tibial fixations in primary anterior cruciate ligament reconstruction (ACL-R), and the clinical outcomes and complication profiles of each fixation method. Greater understanding of the optimal graft fixation technique for quadriceps tendon (QT) autografts may assist surgeons in improving outcomes after ACL-R. PubMed, Embase, and Medline were searched from database inception to September 2017, and again to July 2018, and identified 3,670 articles, 21 studies of which satisfied inclusion/exclusion criteria. Across included studies, 1,155 QT ACL-R patients (mean age, 28.7 years [range, 15-59 years], with mean postoperative follow-up of 36.1 months [range, 3.4-120 months]), were analyzed. Suspensory fixation on both sides demonstrated a higher percentage of patients (81.7%) achieving the highest rating of "A or B" on the International Knee Documentation Committee (IKDC) knee ligament examination form compared with aperture fixation on both sides (67.7%). Moreover, suspensory fixation had a lower side-to-side difference in anterior laxity (1.6 mm) when compared with aperture fixation (2.3 mm). Among studies which reported graft failure, all of which employed aperture fixation, the rate was 3.2%. Across available data, primary ACL-R using QT grafts appears to have successful short-term outcomes with a short-term graft failure rate of 3% independent of fixation method. While there is limited data regarding the comparison of aperture and suspensory soft-tissue quadriceps tendon (SQT) fixation in ACL-R, the findings of this systematic review suggest that suspensory fixation and aperture fixation in both the femoral and tibial tunnels are equally efficacious based on clinical outcome data on IKDC grade and measured laxity. This is a level IV, systematic review study.

No Difference in Functional Outcomes When Lateral Extra-Articular Tenodesis Is Added to Anterior Cruciate Ligament Reconstruction in Young Active Patients: The Stability Study

PURPOSE

To assess the functional outcomes of patients included in the Stability Study randomized controlled trial comparing anterior cruciate ligament reconstruction (ACLR) alone with ACLR with lateral extra-articular tenodesis (LET) at 6, 12, and 24 months postoperatively.

METHODS

Six hundred eighteen patients undergoing ACLR, all under the age of 25 years either returning to contact pivoting sport or displaying signs of high-grade rotatory laxity or generalized ligamentous laxity, were randomly assigned to receive ACLR alone or ACLR plus LET. A total of 356 of these patients were randomized at centers participating in the functional assessments. Our primary outcome was Limb Symmetry Index, calculated using a series of 4-hop tests at 6, 12, and 24 months postoperatively. Secondary outcome measures included pain, patient-reported function, and isokinetic strength testing.

RESULTS

We found no statistically significant difference in the proportion of patients either unwilling or unfit to complete the hop testing in the ACLR alone or ACLR with LET group at 6 months (40 vs 40 respectively; P = 1.00), 12 months (25 vs 27; P = .76), and 24 months (21 vs 23; P = .87). Of those who completed hop testing, there were no statistically significant differences between groups in Limb Symmetry Index at 6, 12, or 24 months. Self-reported function (Lower Extremity Functional Score) significantly favored the ACLR alone group at 3 (P = .01) and 6 months (P = .02) postoperative but was similar by 12 months postoperative. Pain scores (P4) also showed a statistically significant difference in favor of the ACL alone group, but this also resolved by 6 months. Quadriceps peak torque (P = .03) and average power (P = .01) were also significantly different in favor of the ACLR alone group at 6 months postoperative; however, these were similar between groups by 12 months postoperative (P = .11 and P = .32, respectively).

CONCLUSIONS

The addition of a LET to ACLR results in slightly increased pain, a mild reduction in quadriceps strength, and reduced subjective functional recovery up to 6 months postoperatively. However, these differences do not have any impact on objective function as measured by hop test limb symmetry index.

LEVEL OF EVIDENCE

I, Randomized Controlled Trial.

Significant Loss of ACL Graft Force With Tibial-Sided Soft Tissue Interference Screw Fixation Over 24 Hours: A Biomechanical Study

Background

Tibial-sided graft fixation is thought to be critical for the success of anterior cruciate ligament (ACL) reconstruction. Nevertheless, little is known about the graft force after fixation during the first 24 hours after surgery or the influence of screw diameter and length during this time.

Purpose

To investigate the force, over the course of 24 hours, in soft tissue grafts secured with a tibial interference screw and to evaluate the effect of different screw diameters (7, 8, and 9 mm) and lengths (25 and 30 mm) on the force in these grafts.

Study Design

Controlled laboratory study.

Methods

Quadruple-strand flexor tendon grafts were fixed with bioabsorbable interference screws in 60 porcine tibiae. Grafts were pretensioned at 80 N over 10 minutes, and screws were inserted outside-in while a preload force of 80 N was applied. Different screw lengths (25 and 30 mm) and diameters (7, 8, and 9 mm), resulting in 6 groups with 10 specimens each, were tested. After release of the preload, graft force was recorded over 24 hours.

Results

A significant decrease in graft force progressed in all groups over the 24-hour period. In total, a median loss of 75 N (IQR, 68-79 N) compared with the initial loading force was observed. Compared with the loading force of 80 N, this corresponded to a median loss of 91%. No significant differences in the remaining graft force could be found among the 6 different screw length and diameter groups after 10 minutes, 100 minutes, or 24 hours.

Conclusion

Graft force in soft tissue grafts secured with a tibial interference screw decreased substantially over the first 24 hours after fixation. Neither the screw diameter nor the screw length affected the decrease in graft force. This raises substantial questions regarding the remaining fixation strength in vivo.

Clinical Relevance

It should not be expected that ACL reconstruction can mechanically restabilize an injured knee as would an intact ACL. Reconstructed knees should be protected from mechanical overload in the early postoperative period.

Evaluating for Tunnel Convergence in Anterior Cruciate Ligament Reconstruction With Modified Lemaire Tenodesis: What Is the Best Tunnel Angle to Decrease Risk?

PURPOSE

The purpose of this study was to analyze postoperative computed tomography (CT) scan evaluations of patients who had undergone a combined anterior cruciate ligament (ACL) reconstruction and modified Lemaire anterolateral tenodesis (ALT) with femoral fixation through a bony tunnel.

METHODS

Postoperative CT scans of 52 patients who had undergone combined ACL and ALT were prospectively evaluated. ACL femoral tunnels were drilled through an anteromedial portal in the center of the native footprint. An ALT fixation tunnel was drilled 5 mm proximal to the lateral epicondyle, aiming at an inclination of 30° proximally and 30° anteriorly. Two independent observers evaluated the CT scans measuring any degree of collision, the shortest distance between the tunnels, and the inclination of the ALT tunnels. Measurements were carried out at both the cortical level and on a plane passing 1 cm deeper in the lateral condyle.

RESULTS

At the level of the cortex, no convergence of the tunnels was identified. In 14 of 52 cases (26.9%), the shortest distance between the tunnels was less than 5 mm. Tunnel collision occurred in 8 of 52 cases (15.4%), and the bone bridge between the tunnels was less than 5 mm in 11 cases (21.1%) when the measurements were made on the deeper plane. When the inclination on the axial plane was less than 15°, a collision always (P < .001) occurs. When it was more than 20°, no collision occurred (P < .001). No correlation between convergence and the inclination of the ALT tunnel on the coronal plane was detected.

CONCLUSIONS

To fix a modified Lemaire ALT through a femoral tunnel avoiding any interference with an anatomic femoral ACL tunnel, we recommend that the femoral tunnel be drilled with an inclination of at least 20° anteriorly.

LEVEL OF EVIDENCE

IV, therapeutic case series.

Lateral Extra-articular Tenodesis Reduces Failure of Hamstring Tendon Autograft Anterior Cruciate Ligament Reconstruction: 2-Year Outcomes From the STABILITY Study Randomized Clinical Trial

BACKGROUND

Persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR) has been correlated with poor clinical outcomes and graft failure.

HYPOTHESIS

We hypothesized that a single-bundle, hamstring ACLR in combination with a lateral extra-articular tenodesis (LET) would reduce the risk of ACLR failure in young, active individuals.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

This is a multicenter, prospective, randomized clinical trial comparing a single-bundle, hamstring tendon ACLR with or without LET performed using a strip of iliotibial band. Patients 25 years or younger with an ACL-deficient knee were included and also had to meet at least 2 of the following 3 criteria: (1) grade 2 pivot shift or greater, (2) a desire to return to high-risk/pivoting sports, (3) and generalized ligamentous laxity (GLL). The primary outcome was ACLR clinical failure, a composite measure of rotatory laxity or a graft rupture. Secondary outcome measures included the P4 pain scale, Marx Activity Rating Scale, Knee injury Osteoarthritis and Outcome Score (KOOS), International Knee Documentation Committee score, and ACL Quality of Life Questionnaire. Patients were reviewed at 3, 6, 12, and 24 months postoperatively.

RESULTS

A total of 618 patients (297 males; 48%) with a mean age of 18.9 years (range, 14-25 years) were randomized. A total of 436 (87.9%) patients presented preoperatively with high-grade rotatory laxity (grade 2 pivot shift or greater), and 215 (42.1%) were diagnosed as having GLL. There were 18 patients lost to follow-up and 11 who withdrew (~5%). In the ACLR group, 120/298 (40%) patients sustained the primary outcome of clinical failure, compared with 72/291 (25%) in the ACLR+LET group (relative risk reduction [RRR], 0.38; 95% CI, 0.21-0.52; P < .0001). A total of 45 patients experienced graft rupture, 34/298 (11%) in the ACLR group compared with 11/291 (4%) in the ACL+LET group (RRR, 0.67; 95% CI, 0.36-0.83; P < .001). The number needed to treat with LET to prevent 1 patient from graft rupture was 14.3 over the first 2 postoperative years. At 3 months, patients in the ACLR group had less pain as measured by the P4 (P = .003) and KOOS (P = .007), with KOOS pain persisting in favor of the ACLR group to 6 months (P = .02). No clinically important differences in patient-reported outcome measures were found between groups at other time points. The level of sports activity was similar between groups at 2 years after surgery, as measured by the Marx Activity Rating Scale (P = .11).

CONCLUSION

The addition of LET to a single-bundle hamstring tendon autograft ACLR in young patients at high risk of failure results in a statistically significant, clinically relevant reduction in graft rupture and persistent rotatory laxity at 2 years after surgery.

REGISTRATION

NCT02018354 ( ClinicalTrials.gov identifier).

Cyclic testing of tibialis tendon allografts for anterior cruciate ligament reconstruction using suture-post versus spiked washer tibial fixation

BACKGROUND

The purpose of this study was to directly compare spiked washer and suture-post tibial-sided fixation techniques used for anterior cruciate ligament reconstruction by measuring anterior tibial translation during cyclic tests.

METHODS

Fresh-frozen human knees were tested using a robotic system that applied 250 cycles of anterior-posterior tibial force (134 N) at 30° flexion, while recording tibial translation. Ten intact knees were tested to collect baseline data for native specimens. A single knee was selected to test ligament reconstructions using doubled tibialis tendon allografts. All grafts were fixed proximally using an EndoButton™, and the tibial end of the graft was fixed with either a spiked washer or with a suture post placed at two different locations (near and distant) relative to the tibial tunnel.

FINDINGS

Mean first cycle translation for intact knees was 4.8 (sd 1.8) mm; means after reconstruction were 2.6 (sd 0.9) mm (spiked washer), 10.1 (sd 1.9) mm (suture post near), and 10.4 (sd 1.5) mm (suture post distant). Corresponding means for translation increase over 250 cycles were 0.3 (sd 0.2) mm, 3.6 (sd 1.3) mm, 7.2 mm (sd 0.9) mm, and 8.0 (sd 1.3) mm. All mean increases (first cycle and cyclic) after ACL reconstruction were significantly greater than those for the intact knees, and all means with a suture post were significantly greater than those with a spiked washer. There were no significant differences between mean translations for near and distant suture post locations.

INTERPRETATION

Use of suture post fixation for anterior cruciate ligament reconstruction is questioned since increases in anterior tibial translation could lead to excessive post-operative knee laxity and possibly early clinical failure.

The Stability study: a protocol for a multicenter randomized clinical trial comparing anterior cruciate ligament reconstruction with and without Lateral Extra-articular Tenodesis in individuals who are at high risk of graft failure

Background

The purpose of anterior cruciate ligament reconstruction (ACLR) is to restore stability to the knee. Persistent rotational laxity following ACLR has been correlated with poor outcome and graft failure. We hypothesize that anterolateral complex reconstruction by way of a Modified Lemaire Lateral Extra-articular Tenodesis (LET) in combination with single bundle ACLR would reduce the risk of persistent rotatory laxity in young individuals who are deemed as being at high risk of failure. We will conduct a pragmatic, multicenter, randomized clinical trial comparing standard single bundle hamstring ACLR with combined ACLR and LET.

Methods

Six-hundred patients (300 per group) aged 25 years or less with an ACL deficient knee that meet two of the following three criteria will be included: 1) Grade 2 pivot shift or greater; 2) Returning to high risk cutting or pivoting sports; 3) Generalized ligamentous laxity. Participants will be seen at 3-months, 6-months, 12-months and 24-months post-operatively. The primary outcome measure is graft failure requiring revision ACLR or symptomatic instability associated with a positive asymmetric pivot shift indicating persistent rotational laxity. Patients will complete secondary outcome measures at each follow-up visit including patient-reported outcome measures, functional and biomechanical testing, and magnetic resonance imaging.

Discussion

This protocol is the first adequately powered randomized clinical trial investigating the effects of augmenting ACLR with an LET in patients at high-risk of graft failure. The successful completion of this trial has the potential to change surgical practice and provide evidence for the role of the LET in ACLR.

Trial registration

The trial is registered at ClinicalTrials.gov: NCT02018354, 23-12-2013.

Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autografts for Primary Anterior Cruciate Ligament Reconstruction: A Systematic Review of Overlapping Meta-analyses

BACKGROUND

Previous meta-analyses have compared bone-patellar tendon-bone (BPTB) with hamstring tendon (HT) autografts for primary anterior cruciate ligament reconstruction (ACLR).

PURPOSE

To conduct a systematic review of overlapping meta-analyses comparing BPTB with HT autografts for ACLR to determine which meta-analyses provide the best available evidence.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was performed by searching the PubMed and Cochrane Library databases. Search words included "anterior cruciate ligament" AND "patellar tendon" AND "hamstring tendon" AND "meta-analysis." Results were reviewed to determine study eligibility. Patient outcomes and postoperative complications were extracted from the included meta-analyses. Meta-analysis quality was assessed using the Oxman-Guyatt and Quality of Reporting of Meta-analyses (QUOROM) scores. The Jadad decision algorithm was then utilized to determine which meta-analyses provided the best level of evidence.

RESULTS

Sixteen meta-analyses containing an average of 1396 patients met the eligibility criteria. Most studies found BPTB autografts to provide superior stability but more postoperative complications, such as anterior knee pain and kneeling pain. Studies by Gabler et al (2016), Mohtadi et al (2011), and Xie et al (2015) received the highest Oxman-Guyatt and QUOROM scores, and therefore, these meta-analyses proved to provide the highest level of evidence. Additionally, Xie et al was selected as the highest-quality study in this systematic review based on the Jadad decision algorithm.

CONCLUSION

The current best evidence suggests that ACLR with BPTB autografts provides superior static knee stability and that there are fewer postoperative complications in ACLR with HT autografts.

Suspensory Versus Aperture Fixation of a Quadrupled Hamstring Tendon Autograft in Anterior Cruciate Ligament Reconstruction: A Meta-analysis

BACKGROUND

Hamstring grafts have become a popular choice for anterior cruciate ligament (ACL) reconstruction; however, the most effective means of fixation of these soft tissue grafts is unknown.

PURPOSE

To determine whether suspensory or aperture fixation of hamstring tendon autografts provides better stability and clinical outcomes in ACL reconstruction.

STUDY DESIGN

Meta-analysis.

METHODS

A literature search of studies reporting single-bundle ACL reconstructions using 4-stranded hamstring tendon autografts with aperture or suspensory fixation with a minimum 24-month follow-up was conducted. Stability and clinical outcomes were compared for aperture versus suspensory fixation. Knee stability was measured with the Lachman or pivot-shift test or KT-1000 arthrometer side-to-side difference (SSD), and outcomes were determined with the International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores as well as graft failures. A random-effects model with a pooled estimate for the between-study variance was used to estimate proportions or means for each outcome and its corresponding 95% CI.

RESULTS

Forty-one studies were included, of which 20 utilized suspensory fixation techniques and 21 utilized aperture fixation techniques. A >3-mm SSD was seen more often in the aperture group than the suspensory group, which was statistically significant ( P < .0001), but there was no significant difference between groups for a >5-mm SSD ( P = .53). The aperture group demonstrated significantly more graft ruptures than did the suspensory group ( P = .03). There were no statistically significant differences in Lachman grade 0 ( P = .76), grade 1 ( P = .89), and grade 2 ( P = .55) or pivot-shift grade 0 ( P = .72), grade 1 ( P = .97), and grade 2 ( P = .28). There was no statistically significant difference in mean continuous IKDC ( P = .80), Tegner ( P = .34), or Lysholm ( P = .84) scores.

CONCLUSION

This meta-analysis demonstrated improved overall arthrometric stability and fewer graft ruptures using suspensory fixation compared with aperture fixation of a quadrupled hamstring tendon autograft in ACL reconstruction. There were no differences in IKDC, Lysholm, Lachman, and pivot-shift outcomes between suspensory and aperture fixation.

Anatomic Anterior Cruciate Ligament Reconstruction via Independent Tunnel Drilling: A Systematic Review of Randomized Controlled Trials Comparing Patellar Tendon and Hamstring Autografts

PURPOSE

To collect the highest level of evidence comparing anatomic anterior cruciate ligament (ACL) reconstruction via independent tunnel drilling using bone-patellar tendon-bone (BTB) and hamstring tendon (HT) autografts in terms of clinical outcome and failure rate.

METHODS

We performed a systematic review of clinical trials that randomized patients to ACL reconstruction with either BTB or HT autografts with a minimum 2-year follow-up. Only trials using independent tunnel drilling, including outside-in and anteromedial portal techniques, for both autografts were eligible for inclusion, whereas all transtibial studies were excluded. Study design, demographics, surgical technique, rehabilitation protocol, and clinical outcomes were compiled. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Quality assessment was performed using the Coleman Methodological Scale (CMS).

RESULTS

Six published studies reporting on 5 randomized controlled trials (RCTs) met the inclusion criteria. No study reported a difference in rerupture rate between BTB and HT. BTB-reconstructed knees experienced a greater incidence of anterior knee pain or crepitus in 2/7 trials and radiographic evidence of degenerative change in 3/7 trials. HT-reconstructed knees had increased instrumented laxity in 2/7 trials and less knee flexion strength postoperatively.

CONCLUSIONS

This study collects all available Level I and II evidence for anatomic ACL reconstruction using BTB and HT grafts. According to the data presented in these studies, clinical outcome scores and failure rates showed no differences for anatomic reconstruction using either autograft. However, in some studies, BTB-reconstructed knees experienced a greater incidence of anterior knee pain and radiographic evidence of degenerative change, and in others, HT-reconstructed knees had increased laxity and less knee flexion strength. In our opinion, both BTB and HT autografts remain valid options for ACL reconstruction when using anatomic drilling techniques, providing a stable knee with reliable return to activity.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Credibility and quality of meta-analyses addressing graft choice in anterior cruciate ligament reconstruction: a systematic review

PURPOSE

This systematic review examined the methodological credibility and quality of reporting of all meta-analyses which have compared bone-patellar tendon-bone (BPTB) versus hamstring tendon (HT) for anterior cruciate ligament (ACL) reconstruction (ACLR).

METHODS

EMBASE, MEDLINE, and The Cochrane Library were systematically searched, and two reviewers independently assessed eligibility, credibility according to the Users' Guide to medical literature, and completeness of reporting according to the preferred reporting items for systematic review and meta-analyses (PRISMA) checklist. Inter-rater agreement was quantified using Kappa, and we used Pearson's correlation coefficient to evaluate potential associations.

RESULTS

Seventeen meta-analyses were identified comparing BPTB versus HT for ACLR. The majority of meta-analyses were published in 2011 (5; 29 %), and North America was the most common continent of publication (6; 35 %). The three most commonly reported outcomes were stability (82 %), complications (76 %), and function (return to sport, IKDC score) (71 %). The median number of satisfactorily reported items in the Users' Guide was three out of seven (IQR 2-4). The median number of satisfactorily reported items in PRISMA for the meta-analyses was 20 out of 27 (IQR 19-22).

CONCLUSION

The credibility of the meta-analyses comparing BPTB versus HT autograft for ACLR although limited is improving with time. Earlier studies had limited methodological rigour; however, the more recent studies have shown promise in improved methodology. The study findings suggest that decisions should be made on a case-to-case basis with coordination of patient factors and preferences as well as surgeon experience on the background of the best available evidence.

LEVEL OF EVIDENCE

IV.

Cadaveric Study Comparing the Biomechanical Properties of Grafts Used for Knee Anterolateral Ligament Reconstruction

PURPOSE

To measure the biomechanical properties (maximum load, stiffness, and elongation) of the anterolateral ligament (ALL), gracilis, and iliotibial band (ITB) within the same subject.

METHODS

Thirteen unpaired knees were used (7 women, 6 men). The donors had a mean age at death of 54 years (range: 37 to 70 years). The mechanical properties of two types of ALL grafts were evaluated: ITB and two-strand gracilis. The mechanical properties of ALL were also measured. Validated methods were used to perform the tensile tests to failure and to record the results. Student's t-test was used to compare the various samples.

RESULTS

The maximum load to failure was 141 N (±40.6) for the ALL, 200.7 N (±48.7) for the gracilis, and 161.1 N (±27.1) for the ITB. Only the gracilis had a significantly higher failure load than ITB and ALL (P = .001 and P = .03). The stiffness was 21 N mm^-1 (±8.2) for the ALL, 131.7 N mm^-1 (±43.7) for the gracilis, and 39.9 N mm^-1 (±6) for the ITB. The elongation at failure was 6.2 mm (±3.2) for the ALL, 19.9 mm (±6.5) for the gracilis, and 20.8 mm (±14.7) for the ITB.

CONCLUSIONS

The gracilis had the highest maximum load to failure. The ITB's mechanical properties most closely resemble those of the ALL.

CLINICAL RELEVANCE

The biomechanical properties of each potential ALL graft can be factored in when deciding which type of graft to use.

Surgical Indications and Technique for Anterior Cruciate Ligament Reconstruction Combined with Lateral Extra-articular Tenodesis or Anterolateral Ligament Reconstruction

After anterior cruciate ligament (ACL) rupture, anteroposterior and rotational laxity in the knee causes instability, functional symptoms, and damage to other intra-articular structures. Surgical reconstruction aims to restore the stability in the knee, and to improve function and ability to participate in sports. It also protects cartilage and menisci from secondary injuries. Because of persistent rotational instability after ACL reconstruction, combined intra-articular and extra-articular procedures are more commonly performed. In this article, an overview of anatomy, biomechanical studies, current gold standard procedures, techniques, and research topics are summarized.

Reconstruction of anterior cruciate ligament and anterolateral ligament using interlinked hamstrings - technical note

Recent anatomical and biomechanical studies on the anterolateral ligament (ALL) of the knee have shown that this structure has an important function in relation to joint stability, especially when associated with anterior cruciate ligament (ACL) injury. However, the criteria for its reconstruction have not yet been fully established and the surgical techniques that have been described present variations regarding anatomical points and fixation materials. This study presents a reproducible technique for ALL and ACL reconstruction using hamstring tendons, in which three interference screws are used for fixation.

A Systematic Summary of Systematic Reviews on the Topic of the Anterior Cruciate Ligament

BACKGROUND

There has been a substantial increase in the amount of systematic reviews and meta-analyses published on the anterior cruciate ligament (ACL).

PURPOSE

To quantify the number of systematic reviews and meta-analyses published on the ACL in the past decade and to provide an overall summary of this literature.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review of all ACL-related systematic reviews and meta-analyses published between January 2004 and September 2014 was performed using PubMed, MEDLINE, and the Cochrane Database. Narrative reviews and non-English articles were excluded.

RESULTS

A total of 1031 articles were found, of which 240 met the inclusion criteria. Included articles were summarized and divided into 17 topics: anatomy, epidemiology, prevention, associated injuries, diagnosis, operative versus nonoperative management, graft choice, surgical technique, fixation methods, computer-assisted surgery, platelet-rich plasma, rehabilitation, return to play, outcomes assessment, arthritis, complications, and miscellaneous.

CONCLUSION

A summary of systematic reviews on the ACL can supply the surgeon with a single source for the most up-to-date synthesis of the literature.

Comparison of Patellar Tendon and Hamstring Tendon Anterior Cruciate Ligament Reconstruction: A 15-Year Follow-up of a Randomized Controlled Trial

BACKGROUND

Numerous studies have compared patellar tendon (PT) and hamstring tendon (HS) anterior cruciate ligament (ACL) reconstructions in the short to midterm, but fewer long-term results have been published.

HYPOTHESIS

There will be no difference in functional outcome between ACL reconstruction performed with PT and HS grafts, but PT grafts will have more donor site morbidity.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Sixty-five patients undergoing ACL reconstruction were randomized to receive either a PT graft or a 4-strand HS graft. Early results were reported at 4, 8, 12, 24, and 36 months. Forty-seven patients (22 of 31 PT and 25 of 34 HS) were reviewed at a mean of 15.3 years.

RESULTS

Four graft ruptures (1 PT, 3 HS) and 6 contralateral ACL injuries (4 PT, 2 HS) occurred in the group that was reviewed. There was no statistically significant difference between the groups for any of the variables measured. There was a similar incidence of anterior knee pain and kneeling pain in both groups. The previously observed increased extension deficit in the PT group at 3 years was not present at 15 years, and there was no significant between-group difference in knee laxity. A higher proportion of patients in the PT group were participating in sport on a weekly basis (73% PT, 48% HS; P = .05). There was no difference in the degree of osteoarthritis between the groups.

CONCLUSION

This randomized controlled trial showed that HS and PT ACL reconstructions have comparable results at an average 15-year follow-up. Contrary to the study hypothesis, some of the graft differences seen at earlier review were not present at 15 years, and patients with PT grafts were more active in sport participation. Overall, both graft types provided good long-term subjective and objective outcomes.

Analysis of biomechanical properties of patellar ligament graft and quadruple hamstring tendon graft

INTRODUCTION

Two types of transplant are commonly used in the surgical management of anterior cruciate ligament lesions: the central part of the patellar ligament and quadruple tendons of the gracilis muscle and semitendinosus muscle.

AIMS

The aim of this study was to determine the biomechanical characteristics of patellar ligament transplants and transplants of the quadruple tendons of the hamstring muscles under tensile force in the laboratory, and to compare the results in each group of samples.

MATERIALS AND METHODS

The study comprised 160 specimens: 40 specimens of gracilis muscle tendons, 40 of semitendinosus muscle tendons, 40 of quadruple tendons and 40 of the patellar ligament, approximately equally distributed according to sex, age (50-70 years) and the side of the body from which the specimen had been taken.

RESULTS

The working curve analysis of the specimens under tensile load of a maximum force of 30N showed the least elongation (0.31%) in the quadruple tendon, followed by the gracilis muscle tendon (1.48%) and patellar ligament tendon (3.91%).

CONCLUSIONS

The quadruple tendon specimen showed greater strength and higher elasticity compared with the patellar ligament specimen, which proved the starting hypothesis.

Histological analysis of cross-sectional area of quadruple hamstring tendons and patellar ligament samples in relation to age and gender

AIMS

The middle of the patellar ligament and the quadruple hamstring tendons (gracilis and semitendinosus) are two types of graft predominantly used in anterior cruciate ligament (ACL) reconstruction. The aim of this study was to determine the morphometric characteristics of patellar ligament grafts and hamstring tendon grafts and to compare the results according to subject age and gender.

MATERIALS AND METHODS

The study was conducted on a total of 120 samples: 40 of gracilis tendon, 40 of semitendinosus tendon and 40 of patellar ligament, distributed equally according to gender, age (50-75 years) and the side of the body from which the sample was harvested.

RESULTS

Morphometric and histological analyses showed that patellar ligament samples had less cross-sectional area than quadruple tendon samples (49.29 mm(2) compared with 51.46 mm(2), respectively). Sexual dimorphism was noticed in distal cross-sections of gracilis tendons (p=0.09), cross-sections of quadruple tendons (p=0.07) and patellar ligament samples (p=0.01) because of different muscular build.

CONCLUSIONS

All samples obtained from male subjects had larger cross-sectional areas compared with the samples taken from females. Furthermore, samples obtained from subjects aged 60 years or under had larger cross-sectional areas than samples obtained from subjects aged at least 61 years for all types of graft.

Biomechanical analysis of simulated clinical testing and reconstruction of the anterolateral ligament of the knee

BACKGROUND

Anatomic anterolateral ligament (ALL) reconstruction has been proposed to assist anterior cruciate ligament (ACL) reconstruction in controlling anterolateral rotational laxity of the knee. However, the biomechanical effects have not been reported.

PURPOSE

(1) To investigate the effect of ALL transection on rotational knee kinematics and (2) to determine the effect on knee biomechanics of ALL reconstruction procedures compared with lateral extra-articular tenodesis (LET).

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 12 cadaveric knee specimens were tested in the following sequence: (1) ACLintact, (2) anteromedial bundle of ACL sectioned (ACLamb), (3) complete ACL sectioned (ACLfull), (4) ALL sectioned (ALLsec), (5) anatomic ALL reconstruction (ALLanat), and (6) LET. Biomechanical anterior drawer and Lachman tests were performed in which a 90-N load was applied to the posterior tibia, and anterior translation was measured. A combined load to simulate the early phase of the pivot-shift test was executed in which a 5-N·m internal rotation moment was applied to a fully extended knee; anterior translation and internal rotation were measured.

RESULTS

Anterior translation increased across conditions for the biomechanical tests. Internal rotation during the simulated early-phase pivot-shift test was significantly different between ACLfull and ALLsec. Anatomic ALL reconstruction did not significantly reduce internal rotation or anterior translation during the simulated early-phase pivot-shift test. After LET, a significant decrease in anterior translation was found. There was no evidence of overconstraint of the knee with either anatomic ALL reconstruction or LET.

CONCLUSION

The ALL demonstrated a role in controlling anterolateral laxity. LET had a composite effect in governing both anterior and rotational laxity. Anatomic ALL reconstruction did not reduce anterolateral rotational laxity.

CLINICAL RELEVANCE

Profiling the biomechanical characteristics of anterolateral reconstruction is integral to understanding the implications and potential benefit of such an additional procedure to ACL reconstruction.

Comparison of grafts for anatomical reconstruction of the ACL: patellar versus semitendinosus/gracilis

OBJECTIVE

To compare the functional results from surgical treatment for anatomical reconstruction of the anterior cruciate ligament (ACL) with a single band, using two types of autologous grafts.

METHODS

Twenty-seven patients who underwent anatomical reconstruction of the ACL by means of the Chambat technique were evaluated prospectively. They were divided into two groups: A, with 14 patients, using grafts from flexor tendons; and B, with 13 patients, using grafts from the patellar tendon. In both groups, fixation was performed using an absorbable interference screw.

RESULTS

Based on the Lysholm score, group A presented a mean score of 71.6 in the first month, while B presented 75. At the end of the sixth month, both groups presented 96.6. Evaluation of the total IKDC showed that in the first month, the majority of the patients, both in group A (85.7%) and in group B (76.9%), presented a knee assessment that was close to normal. In the sixth month, 92.9% of group A had normal presentations, and 100% of group B.

CONCLUSION

According to the Lysholm functional evaluation and the IKDC subjective assessment, there was no statistically significant difference in the results between the groups, and the results were better in the sixth month.

A Three-Dimensional Evaluation of EndoButton Displacement Direction After Anterior Cruciate Ligament Reconstruction in CT Image Using Tunnel Axis

The goal of this study was to propose a threedimensional evaluation of the EndoButton displacement direction after anterior cruciate ligament reconstruction in the multidetector-row computed tomography (MDCT) image by using the tunnel axis. The proposed method was applied experimentally to six subjects. The result of the simulated experiment revealed that the proposed method could analyze EndoButton displacement direction satisfactorily because the error was less than that of the MDCT image resolution. The clinical experiment results revealed displacement relative to the tunnel between time-zero and the followup point. We conclude that the proposed method can quantitatively evaluate the EndoButton displacement direction from the raw MDCT image after anterior cruciate ligament reconstruction; further, our findings suggest that the EndoButton was displaced relative to the tunnel between time-zero and the follow-up point.

Surgical Predictors of Early Revision Surgery After Anterior Cruciate Ligament Reconstruction: Results From the Swedish National Knee Ligament Register on 13,102 Patients

BACKGROUND

An important objective of anterior cruciate ligament (ACL) registries is to detect and report early graft failure and revision surgery after ACL reconstruction.

PURPOSE

To investigate surgical variables and identify predictors of revision surgery after ACL reconstruction.

STUDY DESIGN

Prospective cohort study; Level of evidence, 2.

METHODS

This prospective cohort study was based on data from the Swedish National Knee Ligament Register during the years 2005 through 2011. Eight surgical variables were investigated: graft selection, graft width, single-bundle or double-bundle techniques, femoral graft fixation, tibial graft fixation, injury-to-surgery interval, injuries to menisci, and injuries to cartilage. The primary endpoint was the 2-year incidence of revision surgery. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated and adjusted for confounders by use of multivariate statistics.

RESULTS

A total of 13,102 patients were included (5541 women [42%] and 7561 men [58%]; P < .001). Hamstring tendon autografts accounted for 90% (11,764 patients) of all reconstructions, of which 96% were performed with a single-bundle technique (11,339 patients). Patellar tendon autografts accounted for the remaining 10% (1338 patients). At index reconstruction, observed injuries to menisci and cartilage were common (40% and 28%, respectively). The overall 2-year incidence of revision surgery was 1.60% (women, 1.57%; men, 1.63%; P = .854). Patients with metal interference screw fixation of a semitendinosus tendon autograft on the tibia had a significantly reduced risk of early revision surgery (RR = 0.32; 95% CI, 0.12-0.90; P = .031).

CONCLUSION

Metal interference screw fixation of a semitendinosus tendon autograft on the tibia was an independent predictor of significantly lower 2-year incidence of revision surgery. Graft selection, graft width, a single-bundle or a double-bundle technique, femoral graft fixation, the injury-to-surgery interval, and meniscus injury were not predictors of early revision surgery.

Revision anterior cruciate ligament reconstruction: an update

With the rising number of anterior cruciate ligament (ACL) reconstructions performed, revision ACL reconstruction is increasingly common nowadays. A broad variety of primary and revision ACL reconstruction techniques have been described in the literature. Recurrent instability after primary ACL surgery is often due to non-anatomical ACL graft reconstruction and altered biomechanics. Anatomical reconstruction must be the primary goal of this challenging revision procedure. Recently, revision ACL reconstruction has been described using double bundle hamstring graft. Successful revision ACL reconstruction requires an exact understanding of the causes of failure and technical or diagnostic errors. The purpose of this article is to review the causes of failure, preoperative evaluation, graft selection and types of fixation, tunnel placement, various types of surgical techniques and clinical outcome of revision ACL reconstruction.

Guideline on anterior cruciate ligament injury

The Dutch Orthopaedic Association has a long tradition of development of practical clinical guidelines. Here we present the recommendations from the multidisciplinary clinical guideline working group for anterior cruciate ligament injury. The following 8 clinical questions were formulated by a steering group of the Dutch Orthopaedic Association. What is the role of physical examination and additional diagnostic tools? Which patient-related outcome measures should be used? What are the relevant parameters that influence the indication for an ACL reconstruction? Which findings or complaints are predictive of a bad result of an ACL injury treatment? What is the optimal timing for surgery for an ACL injury? What is the outcome of different conservative treatment modalities? Which kind of graft gives the best result in an ACL reconstruction? What is the optimal postoperative treatment concerning rehabilitation, resumption of sports, and physiotherapy? These 8 questions were answered and recommendations were made, using the "Appraisal of Guidelines for Research and Evaluation" instrument. This instrument seeks to improve the quality and effectiveness of clinical practical guidelines by establishing a shared framework to develop, report, and assess. The steering group has also developed 7 internal indicators to aid in measuring and enhancing the quality of the treatment of patients with an ACL injury, for use in a hospital or practice.

Anterior cruciate ligament graft choices: a review of current concepts

The graft choice for anterior cruciate ligament (ACL) reconstruction continues to be controversial. There are several options available for the treating surgeon, including Bone Patellar Tendon Bone (BPTB) grafts, Hamstring tendon (HT) grafts, allografts and synthetic grafts. Within the last decade there have been several comparative trials and meta-analysis, which have failed to provide an answer with regards to the best graft available. The aim of this review is to understand the current concepts in graft choices for ACL reconstruction.

The evolution of anatomic anterior cruciate ligament reconstruction

Anterior cruciate ligament reconstruction has evolved significantly since the early 1900's, back when an emphasis was placed on repair and not reconstruction. Over the past century, the technique has evolved from intra-articular non anatomic reconstruction, to extra articular reconstruction, back to intra articular (performed arthroscopically), to now, the advent of anatomic insertion site restoration. This review will aim to illustrate the changes that have occurred, describing the rational for this process, based upon anatomical, radiological, biomechanical and clinical studies, all of which have aimed to improve patient function following ACL injury.

COMPARATIVE STUDY OF ACL RECONSTRUCTION WITH ANATOMICAL POSITIONING OF THE TUNNELS USING THE PATELLAR TENDON VERSUS HAMSTRING TENDON

Objective: To compare ACL reconstruction with anatomical positioning of the tunnels using the hamstring or patellar tendons. Methods: We prospectively evaluated 52 patients who underwent ACL reconstruction using the Chambat's technique, with anatomical positioning of the tunnels drilled outside in. They were divided into group A, with 27 patients, using the patellar tendon as a graft, and group B, with 25 patients, using the hamstring. Results: In group A 26 patients were very satisfied or satisfied and 1 unhappy, in group B. 25 patients were very satisfied or satisfied with the procedure (p = 0.990). According to the Lysholm scale, group A had a mean score of 96.11 and group B, 95.32 (p=0.594). In relation to preoperative IKDC, 100% of the patients in group A and 92% of those in group B were IKDC C or D (p = 0.221); in the assessment with a minimum of two-year follow-up, 96% of group A and 92% of group B were IKDC A or B (p = 0.256). The Lachman test, pivot shift, return to sports activities, and the comparative difference in anterior translation (Rolimeter^TM) also showed no statistically significant difference. In group A, 5 patients (18.5%) were unable to kneel on a hard surface, whereas no patient in group B had this complaint. Conclusion: The anterior cruciate ligament reconstruction presents similar results using the hamstring or patellar tendon with anatomical positioning of the tunnels. Drilling the femoral tunnel outside in is a reproducible and accurate option in the correct placement the femoral tunnel.

Patellar tendon versus hamstring tendon autograft for anterior cruciate ligament rupture in adults

BACKGROUND

Reconstruction of the anterior cruciate ligament (ACL) commonly involves patellar tendon (PT) or hamstring tendon(s) (HT) autografts. There is no consensus with respect to the choice between these two grafts in ACL surgery.

OBJECTIVES

This review compared the outcomes of ACL reconstruction using PT versus HT autografts in ACL deficient patients.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (April 2008), the Cochrane Central Register of Controlled Trials (2008, Issue 2), MEDLINE (1966 to April 10 2008), EMBASE (1980 to April 10 2008), conference proceedings and reference lists. No language restrictions were applied.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing outcomes (minimum two year follow-up) following ACL reconstruction using either PT or HT autografts in skeletally mature adults, irrespective of the number of bundles, fixation method or incision technique.

DATA COLLECTION AND ANALYSIS

After independent study selection, the four authors independently assessed trial quality and risk of bias, and extracted data using pre-developed forms. Trial authors were contacted for additional data and information. Risk ratios with 95% confidence intervals were calculated for dichotomous outcomes, and mean differences and 95% confidence intervals for continuous outcomes.

MAIN RESULTS

Nineteen trials providing outcome data for 1597 young to middle-aged adults were included. Many trials were at high risk of bias reflecting inadequate methods of randomization, lack of blinding and incomplete assessment of outcome.Pooled data for primary outcomes, reported in a minority of trials, showed no statistically significant differences between the two graft choices for functional assessment (single leg hop test), return to activity, Tegner and Lysholm scores, and subjective measures of outcome. There were also no differences found between the two interventions for re-rupture or International Knee Documentation Committee scores. There were inadequate long-term results, such as to assess the development of osteoarthritis.All tests (instrumental, Lachman, pivot shift) for static stability consistently showed that PT reconstruction resulted in a more statically stable knee compared with HT reconstruction. Conversely, patients experienced more anterior knee problems, especially with kneeling, after PT reconstruction. PT reconstructions resulted in a statistically significant loss of extension range of motion and a trend towards loss of knee extension strength. HT reconstructions demonstrated a trend towards loss of flexion range of motion and a statistically significant loss of knee flexion strength. The clinical importance of the above range of motion losses is unclear.

AUTHORS' CONCLUSIONS

There is insufficient evidence to draw conclusions on differences between the two grafts for long-term functional outcome. While PT reconstructions are more likely to result in statically stable knees, they are also associated with more anterior knee problems.

Autograft versus allograft: an economic cost comparison of anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to compare the costs associated with anterior cruciate ligament (ACL) reconstruction with either bone-patellar tendon-bone (BPTB) autograft or BPTB allograft.

METHODS

Surgical costs are reported, including supply costs, based on invoice costs per item used per procedure, and personnel costs calculated as cost per minute. All operations were performed at an ambulatory surgery center between March 2005 and March 2006. A total of 160 patients underwent primary ACL reconstruction with either BPTB autograft (n = 106) or BPTB allograft (n = 54). Procedure cost data were retrieved from a financial management database and divided into various categories for comparison of the 2 groups. Payment data were provided by the surgery center's billing office.

RESULTS

The total mean cost per case was $4,147 ± $943 in the allograft group compared with $3,154 ± $704 in the autograft group; this was statistically significant (P < .001). The mean operating room time was 12 minutes greater in autograft cases (P = .006). Supply costs comprised a mean of 58.7% of total expenses in the autograft group and 72.2% in the allograft group.

CONCLUSIONS

Allograft reconstruction of the ACL was significantly more expensive than autograft reconstruction.

LEVEL OF EVIDENCE

Level II, economic analysis.

Does autograft choice determine intermediate-term outcome of ACL reconstruction?

PURPOSE

Many clinical studies and systematic reviews have compared the short-term (2 years) outcomes of ACL reconstruction with hamstring and patellar tendon autograft. Few differences have been observed, with the exception of increased kneeling pain with patellar tendon grafts. The goal of this systematic review is to determine whether there are differences in clinical, patient-reported, or radiographic outcomes based on graft choice at a minimum of 5 years after ACL reconstruction.

METHODS

A systematic review was performed to identify all prospective outcome studies comparing patellar tendon and hamstring autograft ACL reconstruction with minimum follow-up of at least 5 years. Seven studies were identified and meta-analysis of select data determined to be sufficiently homogenous was performed (failure and laxity).

RESULTS

Five randomized controlled trials and two prospective cohorts comparing hamstring and patellar tendon autografts were identified. Clinical assessment [failure rate, International Knee Documentation Committee (IKDC) class, Lachman, pivot shift, and KT 1000 testing] showed no difference between grafts. Patient-reported outcomes (Lysholm, Cincinnati, and IKDC) showed no difference. Both anterior knee pain (3/3 studies) and kneeling pain (4/4 studies) were more frequent in the patellar tendon group. However, the patient-reported outcomes in these studies were not different. Radiographic evidence of osteoarthritis was inconsistent between autograft choices.

CONCLUSION

This level II systematic review demonstrates no difference in major clinical results between graft types with the exception of increased anterior knee and kneeling pain. There exists a potential for increased incidence of osteoarthritis in the patellar tendon group but increased sample size is required. These longer-term outcomes are similar to results of prior systematic reviews with two-year follow-up.

Comparação entre parafuso de interferência e transcondilar na reconstrução do LCA

OBJETIVO: A fixação femoral na reconstrução do Ligamento Cruzado Anterior (LCA) com enxerto de tendões flexores pode variar muito de acordo com a disposição dos materiais e a experiência do cirurgião. Porém os trabalhos que comparam os sistemas de fixação são efetuados na maioria das vezes em cadáveres ou em animais, sem avaliar os resultados clínicos, prejudicando sua comparação com pacientes humanos vivos. Neste artigo avaliamos o resultado clínico de dois métodos de fixação do enxerto ao fêmur (parafuso de interferência de titânio e parafuso transcondilar de titânio) para saber se, do ponto de vista clinico e subjetivo, há diferença entre estes métodos. MÉTODOS: Foram selecionados 40 pacientes com lesão do LCA sendo que 20 pacientes tiveram seu enxerto fixado ao fêmur com parafuso de interferência e 20 com parafuso transcondilar. Todos foram reavaliados com no mínimo dois anos de pós operatório para medição da gaveta anterior, Pivot Shift e teste de Lachman, além da obtenção dos questionário de Lysholm e IKDC (International Knee Documentation Committee). RESULTADOS: Os resultados não foram estatisticamente diferentes para os critérios avaliados. CONCLUSÃO: As duas formas de fixação são eficientes para esta técnica dentro dos parâmetros estabelecidos. Nível de Evidência II, Estudo Prospectivo Comparativo.