Double-bundle reconstruction results in superior clinical outcome than single-bundle reconstruction

Double-bundle anterior cruciate ligament reconstruction resulted in better International Knee Documentation Committee objective grading at fifteen year follow-up compared to single-bundle reconstruction

PURPOSE

The aim of this prospective randomized study was to evaluate whether the use of the anatomic double-bundle (DB) method for anterior cruciate ligament (ACL) reconstruction results in better clinical outcomes and a lower incidence of graft failure compared with the anatomic single-bundle (SB) method. The hypothesis was that DB ACL reconstruction would result in a lower incidence of graft failure.

METHODS

Patients were randomly assigned to either the SB group (n = 78) or the DB group (n = 75). Evaluation included clinical testing, subjective assessments, functional testing, and International Knee Documentation Committee (IKDC) objective grading. Surgical techniques were anatomic, and the rehabilitation protocol was standardized.

RESULTS

At 15-year follow-up, information was available on 100 patients (65%), of whom 55 (36%) were accepted in the final statistical analysis. There were almost three times as many graft failures in the SB group, but the result wasn´t statistically significant. Subjective assessments, knee stability (KT -1000 and pivot shift), range of motion (ROM), and functional one leg hop test showed no statistically significant differences between the groups. However, DB ACL reconstruction resulted in better International Knee Documentation Committee objective grading (P < 0.001).

CONCLUSION

At the 15-year follow-up, double-bundle surgery resulted in significantly better International Knee Documentation Committee objective grading compared to single-bundle surgery.

Function and strain of the anterolateral ligament part II: reconstruction

PURPOSE

Anterolateral rotatory instability (ALRI) may result from isolated ruptures of the anterior cruciate ligament (ACL) or combined lesions with the anterolateral ligament (ALL). Biomechanical studies have demonstrated that the ALL contributes to the overall rotational stability of the knee. The purpose of this study was to investigate the biomechanical function of anatomic ALL reconstruction (ALL_rec) in the setting of a combined ACL and ALL injury and reconstruction. The hypothesis was that combined ACL reconstruction (ACL_rec) and ALL_rec (ACL/ALL_rec) significantly reduces internal rotation and shows load sharing between both reconstructions compared with isolated ACL_rec.

METHODS

Eight fresh-frozen cadaveric knees were evaluated using a six degrees of freedom knee simulator. Continuous passive motion and external loads were tested. Kinematic differences between ACL_rec and combined ACL/ALL_rec were compared. Additionally, ACL graft tension and ALL graft strain were measured continuously throughout the testing protocol.

RESULTS

Combined anatomic ACL/ALL_rec significantly improved the internal rotatory stability compared with isolated ACL_rec at 30°-90° under an internal rotation moment. During a static pivot-shift test, additional ALL_rec showed no significant reduction of ap-translation. ALL_rec resulted in an increase in ACL graft tension during continuous passive motion and with additional internal rotation moment.

CONCLUSION

In the case of a combined ACL and ALL deficiency, concurrent ACL_rec and ALL_rec significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL at flexion angles ≥ 30°. Nevertheless, additional ALL_rec with fixation at 60° and with low tension could not restore extension-near rotatory stability. For that reason, ALL_rec with fixation at 60° flexion cannot be recommended in clinical application.

The Statistical Fragility of Single-Bundle vs Double-Bundle Autografts for ACL Reconstruction: A Systematic Review of Comparative Studies

Background:

The statistical significance of a given study outcome can be liable to small changes in findings. P values are common, but imperfect statistical methods to convey significance, and inclusion of the fragility index (FI) and fragility quotient (FQ) may provide a clearer perception of statistical strength.

Purpose/Hypothesis:

The purpose was to examine the statistical stability of studies comparing primary single-bundle to double-bundle anterior cruciate ligament reconstruction (ACLR) utilizing autograft and independent tunnel drilling. It was hypothesized that the study findings would be vulnerable to a small number of outcome event reversals, often less than the number of patients lost to follow-up.

Study Design:

Systematic review; Level of evidence, 2.

Methods:

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the authors searched PubMed for comparative studies and randomized controlled trials (RCTs) published in select journals, based on impact factor, between 2005 and 2020. Risk-of-bias assessment and methodology scoring were conducted for the included studies. A total of 48 dichotomous outcome measures were examined for possible event reversals. The FI for each outcome was determined by the number of event reversals necessary to alter significance. The FQ was calculated by dividing the FI by the respective sample size.

Results:

Of the 1794 studies screened, 15 comparative studies were included for analysis; 13 studies were RCTs. Overall, the mean FI and FQ were 3.14 (IQR, 2-4) and 0.050 (IQR, 0.032-0.062), respectively. For 72.9% of outcomes, the FI was less than the number of patients lost to follow-up.

Conclusion:

Studies comparing single-bundle versus double-bundle ACLR may not be as statistically stable as previously thought. Comparative studies and RCTs are at substantial risk for statistical fragility, with few event reversals required to alter significance. The reversal of fewer than 4 outcome events in a treatment group can alter the statistical significance of a given result; this is commonly less than the number of patients lost to follow-up. Future comparative study analyses might consider including FI and FQ with P values in their statistical analysis.

Double bundle ACL reconstruction leads to better restoration of knee laxity and subjective outcomes than single bundle ACL reconstruction

PURPOSE

The purpose of this meta-analysis is to compare arthroscopic single bundle (SB) and double bundle (DB) anterior cruciate ligament (ACL) reconstructions in the light of all available randomised controlled trials (RCTs). A meta-analysis of this well-researched topic was performed and subgroup analyses of the medial portal (MP) technique and the transtibial technique (TT) were added as a new idea. The hypothesis was that the DB technique is superior to the SB technique also in subgroup analyses of the MP and TT techniques.

METHODS

Instructions of the PRISMA checklist were followed. Systematic literature search from electronic databases, including PubMed, Cochrane library and Scopus was performed to find RCTs that compared the SB and DB techniques. Nine outcomes were used to compare these two techniques. Each study was assessed according to the Cochrane Collaboration's risk of bias tool and three subgroup analyses (minimum 2-years' follow-up, TT technique and MP technique) were performed.

RESULTS

A total of 40 studies were included in this meta-analysis. When analysing all the included studies, the DB technique was superior to the SB technique in KT-1000/2000 evaluation (p < 0.01), IKDC subjective evaluation (p < 0.05), Lysholm scores (p = 0.02), pivot shift (p < 0.01) and IKDC objective evaluation (p = 0.02). Similar results were also found in the subgroup analyses of minimum 2-years' follow-up and the TT technique. However, there were no differences between the two techniques in a subgroup analysis of the MP technique.

CONCLUSION

Generally, DB ACL reconstruction leads to better restoration of knee laxity and subjective outcomes than SB ACL reconstruction. The subgroup analysis of the MP technique revealed that surgeons can achieve equally as good results with both techniques when femoral tunnels are drilled through the medial portal.

LEVEL OF EVIDENCE

II.

A Systematic Review of Risk Factors for Anterior Cruciate Ligament Reconstruction Failure

Although most studies have introduced risk factors related to anterior cruciate ligament reconstruction failure, studies on combinations of high-risk factors are rare. To provide a systematic review of the risk factors of anterior cruciate ligament reconstruction failure to guide surgeons through the decision-making process, an extensive literature search was performed of the Medline, Embase and Cochrane Library databases. Studies published between January 1, 2009, and September 19, 2019, regarding the existing evidence for risk factors of anterior cruciate ligament reconstruction failure or graft failure were included in this review. Study quality was evaluated with the quality index. Ultimately, 66 articles met our criteria. There were 46 cases classified as technical factors, 21 cases as patient-related risk factors, and 14 cases as status of the knee joint. Quality assessment scores ranged from 14 to 24. This systematic review provides a comprehensive summary of the risk factors for anterior cruciate ligament reconstruction failure, including technical factors, patient-related factors, and the factors associated with the status of the knee joint. Emphasis should be placed on avoiding these high-risk combinations or correcting modifiable risk factors during preoperative planning to reduce the rate of graft rupture and anterior cruciate ligament reconstruction failure.

A Bone-Hamstring Autograft for Arthroscopic Anterior Cruciate Ligament Reconstruction

We describe a bone-hamstring autograft for anterior cruciate ligament reconstruction (ACLR). The semitendinosus and gracilis tendons are harvested using an open tendon stripper, keeping these distal tibial insertions intact. The bone-hamstring autograft is harvested using an oscillating saw. This modified autograft has the following advantages: (1) It possesses the potential for healing with the femur owing to its bone plug; (2) it is perfectly suited for various single-bundle reconstruction methods including oval-tunnel and rectangular-tunnel ACLR, as well as other flat ACLR methods; and (3) it is an attractive option for both primary ACLR and revision ACLR owing to its unique characteristics.

The long-term outcomes of different grafts in anterior cruciate ligament reconstruction: a network meta-analysis

OBJECTIVES

To compare the long-term prognosis of patients with different types of grafts used in anterior cruciate ligament reconstruction (ACLR).

METHODS

PubMed, Ovid (MEDLINE and Embase) and the Cochrane library were searched up to Feb 2020. Eligible studies about different grafts in ACLR were searched for identifying the evidence comparing the long-term (mean or median follow-up time or the general description of the follow-up time≥2 years) knee outcomes of different grafts for ACLR. The final included articles and evaluation criteria were confirmed by the authors and senior clinicians to ensure the validity of the included articles. Lysholm score, the results of pivot shift test, Lachman test and International Knee Documentation Committee (IKDC) evaluation were selected as prognostic indicators. A Bayesian network meta-analysis was conducted.

RESULTS

A total of 30 articles were included in our network meta-analysis. Finally, we found that artificial graft or augmentation can provide the not bad Lysholm score but the worse result of IKDC evaluation for patients with ACLR compared with other types of grafts. Double-bundle hamstring autograft can provide a good Lysholm score as well as lower positive rate of pivot shift test and Lachman test. Patellar tendon autograft can provide the better result of IKDC evaluation. The patients with allogeneic tendon graft may get the higher positive rate of pivot shift test and Lachman test. Patients with single-bundle hamstring autograft may get the ordinary result of IKDC evaluation and Lysholm score.

CONCLUSIONS

Double-bundle hamstring autograft may be a better choice because of more items of good prognosis for the patients with ACLR. Patellar tendon autograft is a right choice which only shows the disadvantage on the Lysholm score. The prognosis of patients with single-bundle hamstring autograft is ordinary. The effect of artificial graft or augmentation needs more evidence to prove. Allogeneic tendon graft is not a better choice when compared with other grafts referred in our network meta-analysis.

TRANSLATIONAL POTENTIAL STATEMENT

In this study, we made a comprehensive comparison of the grafts commonly used in anterior cruciate ligament reconstruction. The evidence presented in this study provides a reference for clinicians to select a suitable anterior cruciate ligament graft.

Outcomes Following Arthroscopic Single and Double Bundle Anterior Cruciate Ligament (ACL) Reconstruction Supported by the Comprehensive Early Rehabilitation Program (CERP)

Background

The aim of this study was to compare the level of functional condition in patients who had rehabilitation with the comprehensive early rehabilitation program (CERP) following either single bundle (SB) or double bundle (DB) anterior cruciate ligament reconstruction (ACLR) using semitendinosus-gracilis tendon graft (ST-G) method. We hypothesized that 12 weeks after reconstruction followed by a rehabilitation program, there would be a difference in clinical results and functional activity between patients.

Material/Methods

This study included 94 patients who had rehabilitation with CERP after knee surgery for a knee injury from a recreational sport. There were 49 patients in Group 1 (mean age, 36.5 years) who had CERP after SB ACLR, and 45 patients in Group 2 (mean age, 35.6 years) who had CERP after DB ACLR. Functional condition was tested using the Lysholm Knee Scoring Scale, and knee stability was measured using KT-2000. The first examination was performed before CERP and the second examination was performed 12 weeks later.

Results

The level of functional condition in both groups was similar before rehabilitation with CERP, with no significant difference (P<0.958) and was considered relatively low. In the second examination, 12 weeks after starting CERP, the patients improved in both groups. The improvement was larger in the SB ACLR Group 1 than in the DB ACLR Group 2. The difference was significant (P<0.005). However, the patients in Group 2 achieved better knee stability scores in the KT-2000 examination than the patients in Group 1. The difference was significant (P=0.035).

Conclusions

We found that the patients from both groups after 12 weeks of CERP achieved an improvement in stability and functional activity within normal limits. However, SB ACLR was more effective than DB ACLR in terms of the level of functionality achieved with CERP but was less effective in terms of knee stability.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of anterior cruciate ligament injury - Secondary publication

BACKGROUND

This clinical guideline presents recommendations for the management of patients with anterior cruciate ligament (ACL) injury, endorsed by the Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Society of Knee, Arthroscopy and Sports Medicine (JOSKAS).

METHODS

The JOA ACL guideline committee revised the previous guideline based on "Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014", which proposed a desirable method for preparing clinical guidelines in Japan. Furthermore, the importance of "the balance of benefit and harm" was also emphasized. This guideline consists of 21 clinical questions (CQ) and 23 background questions (BQ). For each CQ, outcomes from the literature were collected and evaluated systematically according to the adopted study design.

RESULTS

We evaluated the objectives and results of each study in order to make a decision on the level of evidence so as to integrate the results with our recommendations for each CQ. For BQ, the guideline committee proposed recommendations based on the literature.

CONCLUSIONS

This guideline is intended to be used by physicians, orthopedic surgeons, physical therapists, and athletic trainers managing ACL injuries. We hope that this guideline is useful for appropriate decision-making and improved management of ACL injuries.

Long term results after double and single bundle ACL reconstruction: Is there any difference? A meta - analysis of randomized controlled trials

Objective

The double-bundle (DB) techniques are considered to yield better stability of the knee compared with single-bundle (SB) for anterior cruciate ligament (ACL) reconstruction. However, most studies followed up patients in short to middle-term within 5 years, and the longer-term efficacy of SB and DB ACL reconstruction is still beyond consensus. The purpose of this meta-analysis is to compare the longer-term efficacy between double-bundle (DB) and single-bundle (SB) techniques.

Methods

PubMed, EMBASE, and Cochrane Library databases were searched for relevant articles published up to November, 2017 with an English language restriction. The searches were limited to human subjects and randomized controlled trials (RCTs). In addition, the reference lists of identified articles were checked manually to avoid missing other potentially eligible studies. This process was performed iteratively until no additional articles could be included. The quality of the included studies was assessed using The Cochrane Collaboration's risk of bias tool. All statistical analyses were performed with Review Manager soft-ware.

Results

A total of five RCTs involving 294 patients were included finally. No studies were excluded due to insufficient data or low quality. The pooled results showed no statistically significant difference between SB and double bundle DB reconstructions for Lysholm, IKDC, pivot shift, KT scores, and the development of osteoarthritis at a minimum of 5 years. No significant heterogeneity was found across all outcomes.

Conclusion

The best available evidence demonstrated that SB and DB techniques could yield similar efficacy for ACL reconstruction. And no superiority was founded in DB ACL reconstruction with a minimal 5-year follow-up. Given that, the relatively simple and proven techniques of SB ACL reconstruction may be preferable for orthopedic surgeons.

Level of evidence: Level I, Therapeutic Study.

Double-bundle revision anterior cruciate ligament reconstruction is effective in rescuing failed primary reconstruction and re-introducing patients to physical exercise

The anterior cruciate ligament (ACL) is one of a pair of cruciate ligaments in the human knee and is critical for knee stability, as it limits anterior tibial translation on the femur, restrains rotation and resists varus and valgus joint forces. The present study aimed to assess the effect of double-bundle revision anterior cruciate ligament (ACL) reconstruction in improving the subjective and objective functions and re-introducing patients to physical activity after primary ACL reconstruction had failed. A total of 34 patients who underwent double-bundle ACL revision surgeries were included in the present retrospective study. Lysholm, Tegner and IKDC scores as well as KT-2000 arthrometry measures were obtained pre- and post-operatively. The follow-up time was at least 2 years. The results indicated that the IKDC, Lysholm and Tegner scores as well as KT-2000 flexion scores were significantly improved after revision ACL reconstruction. All patients resumed to performing physical exercise activities after revision surgeries, 65% of whom reached pre-injury levels. In conclusion, these results demonstrated that double-bundle revision ACL reconstruction was consistently effective in rescuing failed primary ACL reconstruction and re-introducing patients to physical exercise.

Role of anterolateral reconstruction in patients undergoing anterior cruciate ligament reconstruction

There is renewed interest in anterolateral reconstruction (ALR) for patients undergoing anterior cruciate ligament (ACL) reconstruction. This is the result of isolated ACL reconstruction and double-bundle reconstruction providing inadequate control over the pivot shift, and recent anatomical and biomechanical studies on the anterolateral ligament (ALL) and its role in the knee's rotational stability. From a technical point of view, ALR can be performed either as a continuity of the intra-articular ACL reconstruction or an independent procedure. The typical peripheral grafts (gracilis and semitendinosus tendons, iliotibial band) can be used. The femoral tunnel must be posterior and proximal to the lateral epicondyle, and the tibial tunnel on a line joining Gerdy's tubercle with the ALL's tibial insertion. Tensioning and fixation are done with the knee near full extension and the tibia in neutral rotation. The ALR complication rate reported in older studies (pain, hematoma, scar damage) has been reduced. Relative to isolated ACL reconstruction, ALR does not alter the infection or stiffness rate, and it reduces the re-injury rate and secondary meniscal damage rate. Analysis of the literature has not shown an increased rate of osteoarthritis after ALR. The objective and functional outcomes are equal to those after isolated ACL reconstruction. Control over rotation is improved by adding ALR and the return to pivot sports appears to be more successful. While the indications must still be refined, ALR can be proposed to young patients undergoing ACL reconstruction who participate in high-intensity pivot sports, have a high-grade pivot shift or who have a failed ACL reconstruction.

The evolution of primary double-bundle ACL reconstruction and recovery of early post-operative range of motion

PURPOSE

The aim of this study was to analyse early post-operative range of motion (ROM) as our anatomic double-bundle (DB) anterior cruciate (ACL) reconstruction technique with respect to tunnel placement evolved. It is the hypothesis of this study that more anatomic placement of the femoral insertion site of the anteromedial (AM) bundle of the ACL results in better restoration of early post-operative knee range of motion.

METHODS

Two methods of DB ACL reconstruction regarding more accurate placement of the femoral AM tunnel in relation to its anatomic origin were compared. Patients presenting for 1- and 3-month post-operative clinical visits were examined for passive extension and active flexion by members of the clinical staff. Only patients undergoing primary DB reconstruction with allograft were included in the analyses. To determine the effects of the modified AM bundle placement on recovery of post-operative ROM, patients undergoing surgery in the 6 months before July 2006 (Group A, n = 50) were compared to patients undergoing surgery in the 6 months after July 2006 (Group B, n = 49).

RESULTS

A total of 99 patients met the inclusion criteria. More accurate placement of the AM bundle of the ACL was associated with a smaller side-to-side difference in flexion at 1 month (n.s.) and at 3 months (3° reduction, p < 0.03) after surgery. There was no effect on extension (n.s.) CONCLUSION: More anatomic placement of the femoral insertion of the AM bundle was associated with improved knee flexion. The study translates the findings of previous anatomic basic science research to demonstrate improved restoration of normal joint motion. This ideally leads to improved long-term clinical outcomes and maintenance of joint and cartilage health.

LEVEL OF EVIDENCE

III.

Comparison of transportal and outside-in techniques for posterolateral femoral tunnel drilling in double-bundle ACL reconstruction -three-dimensional CT analysis of bone tunnel geometry

PURPOSE

To comparatively analyze the geometry of the posterolateral femoral (PL) tunnel in double-bundle ACL reconstruction between far anteromedial transportal (TP) and outside-in (OI) drilling techniques based on three-dimensional computed tomography (3DCT) image analysis.

METHODS

Forty patients who underwent anatomic double-bundle hamstring ACL reconstruction using the TP (n: 20) or OI (n: 20) method with postoperative CT data available were included in the study. The analyzed parameters were as follows: location of the intraarticular tunnel aperture, tunnel length, bending angle (angulation of the graft at the intraarticular tunnel aperture), and long axis of the tunnel aperture/drill diameter ratio as a parameter of ellipsoidal geometry.

RESULTS

Anatomical tunnel placement was achieved in both groups. Coalition of the AM and PL tunnel apertures was found in 3 knees in the TP group and 1 knee in the OI group, though no significant difference in the rate of this problem was demonstrated between the groups (P: 0.30). The tunnel length was not significantly different between the groups, while the graft bending angle at the tunnel aperture was significantly larger in the OI group than the TP group (99.4° vs. 63.6°). The long axis/drill diameter ratio averaged 1.23 in the TP group and 1.13 in the OI group with significant intergroup difference.

CONCLUSION

When drilling the PL femoral tunnel in double-bundle ACL reconstruction, anatomic placement of the intraarticular tunnel aperture was feasible in both the TP and OI techniques. The tunnel aperture was rounder and the graft bending angle in knee extended position at the intraarticular aperture was more acute in the OI technique than the TP technique.

LEVEL OF EVIDENCE

Level IV (retrospective comparison of the two patient groups treated at different hospitals).

Function and strain of the anterolateral ligament part I: biomechanical analysis

PURPOSE

Because reconstruction of the anterior cruciate ligament (ACL) in a double-bundle technique did not solve the problem of persistent rotatory laxity after surgery, new potential answers to this issue are of great interest. One of these is an extraarticular stabilization based on the rediscovery of the anterolateral ligament (ALL). Knowledge about its biomechanical function and benchmark data for an optimal reconstruction remain lacking. Therefore, the purpose of this study was to assess the function of the ALL under passive motion, anterior tibial translation and tibial rotational moments.

METHODS

Continuous passive motion (0°-120° flexion), ap-translation and static pivot shift tests were performed on eight cadaveric knees. The knees were measured in intact, ACL-resected (ACL_res) and ACL + ALL-resected (ALL_res) conditions. Ap-translation and static pivot shift under 134 N anterior shear load were determined at 0°, 30°, 60° and 90° flexion. Strain of the ALL was recorded in intact and ACL_res conditions.

RESULTS

During continuous passive motion under unloaded conditions, no significant difference in internal rotation between ACL_res and ALL_res was observed. With an additional internal tibial torque of 1-4 Nm, internal rotation increased significantly between 60° and 120° after resection of the ALL (p ≤ 0.05). Anterior tibial translation was significantly higher at 30° in ALL_res (p = 0.01) and for a simulated pivot shift at 60° and 90° in ACL_res (p ≤ 0.01). The ALL was not strained under unloaded passive motion. Adding different internal tibial torques led to strain starting at 60° flexion (1 N m internal torque) and 15° flexion (4 N m internal torque) in intact ligaments. In ACL_res, significantly greater ALL strains under lower flexion angles were seen for each condition (p ≤ 0.05).

CONCLUSIONS

This study demonstrated the ALL to be without function under passive motion and with no influence on tibial rotation. On application of extrinsic loads, the ALL had a low but significant stabilizing effect against anterior tibial shear load at low flexion angles. For this reason, it can be concluded that the ALL is supporting the ACL against internal tibial loads to a minor degree. A relationship between the ALL and the pivot shift cannot be concluded. With these results ALL-reconstruction cannot be recommended at the moment without further biomechanical investigations.

Systemic Review of Anatomic Single- Versus Double-Bundle Anterior Cruciate Ligament Reconstruction: Does Femoral Tunnel Drilling Technique Matter?

PURPOSE

To provide an up-to-date assessment of the difference between anatomic double-bundle anterior cruciate ligament (ACL) reconstruction (DB-ACLR) and anatomic single-bundle ACL reconstruction (SB-ACLR). We hypothesized that anatomic SB-ACLR using independent femoral drilling technique would be able to achieve kinematic stability as with anatomic DB-ACLR.

METHODS

A comprehensive Internet search was performed to identify all therapeutic trials of anatomic DB-ACLR versus anatomic SB-ACLR. Only clinical studies of Level I and II evidence were included. The comparative outcomes were instrument-measured anterior laxity, Lachman test, pivot shift, clinical outcomes including objective/subjective International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner activity scale and complication rates of extension/flexion deficits, graft failure, and early osteoarthritis. Subgroup analyses were performed for femoral tunnel drilling techniques including independent drilling and transtibial (TT) drilling.

RESULTS

Twenty-two clinical trials of 2,261 anatomically ACL-reconstructed patients were included in the meta-analysis. Via TT drilling technique, anatomic DB-ACLR led to improved instrument-measured anterior laxity with a standard mean difference (SMD) of -0.42 (95% confidence interval [CI] = -0.81 to -0.02), less rotational instability measured by pivot shift (SMD = 2.76, 95% CI = 1.24 to 6.16), and higher objective IKDC score with odds ratio (OR) of 2.28 (95% CI = 1.19 to 4.36). Via independent drilling technique, anatomic DB-ACLR yielded better pivot shift (SMD = 2.04, 95% CI = 1.36 to 3.05). Anatomic DB-ACLR also revealed statistical significance in subjective IKDC score compared with anatomic SB-ACLR (SMD = 0.27, 95% CI = 0.05 to 0.49).

CONCLUSIONS

Anatomic DB-ACLR showed better anterior and rotational stability and higher objective IKDC score than anatomic SB-ACLR via TT drilling technique. Via independent drilling technique, however, anatomic DB-ACLR only showed superiority of rotational stability. All clinical function outcomes except subjective IKDC score were not significantly different between anatomic DB-ACLR and SB-ACLR.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and II studies.

Objective measurements of static anterior and rotational knee laxity

Several devices allow to measure anterior and rotational static knee laxity. To date, the use of rotational laxity measurements in the daily clinical practice however remains to be improved. These measurements may be systematically integrated to the follow-up of knee injuries. Physiologic laxity measurements may particularly be of interest for the identification of risk factors in athletes. Furthermore, knee laxity measurements help to improve the diagnosis of knee soft tissue injuries and to follow up reconstructions. Further prospective follow-ups of knee laxity in the injured/reconstructed knees are however required to conclude on the best treatment strategy for knee soft tissue injuries.

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.

Patient expectations of primary and revision anterior cruciate ligament reconstruction

PURPOSE

Unrealistic patient expectations have been shown to negatively influence patient-reported outcomes in orthopaedic surgery. Knowledge about patient expectations is important to associate preoperative expectations with the reasonable outcome of a specific procedure. The purpose of this study was to prospectively analyse and to compare patient expectations of primary and revision anterior cruciate ligament reconstruction (ACLR) and to assess the factors associated with patient expectations.

METHODS

Preoperative expectations of 181 consecutive patients undergoing ACLR were assessed prospectively using a 5-item questionnaire. Primary ACLR (P-ACLR) was performed in 133 patients (73%), whereas 48 patients (27%) underwent revision ACLR (R-ACLR). The questionnaire assessed the expectation of the overall condition of the knee joint, return to sports, instability, pain, and risk of osteoarthritis.

RESULTS

All patients expected a normal (38%) or nearly normal (62%) condition of the knee joint. Return to sports at the same level was expected by 91%. With regard to instability (pain), no instability (pain) independent of the activity level was expected by 77% (58%). No or only a slightly increased risk of the development of osteoarthritis was expected by 98%. The R-ACLR group showed a significantly lower expectation of the overall condition (p = 0.001), return to sports (p < 0.001), and pain (p = 0.002). No statistically significant difference was found between female and male patients (n.s.). In the P-ACLR group, patients with a history of previous knee surgery showed inferior expectations of return to sports (p = 0.015) and risk of osteoarthritis (p = 0.011). Age, number of previous knee surgeries, and pre-injury sports level significantly influenced patient expectations.

CONCLUSIONS

Overall, patient expectations of ACL reconstruction are high. Patients undergoing revision ACL reconstruction have lower but still demanding expectations. Younger patients, patients without a history of knee surgery, and highly active patients have higher expectations. Explicit patient information about realistic goals of ACL reconstruction seems to be necessary in order to prevent postoperative dissatisfaction despite a successful operation in the surgeons' point of view.

LEVEL OF EVIDENCE

Prospective case series, Level IV.

Arthroscopic anatomic double bundle anterior cruciate ligament reconstruction: Our experience with follow-up of 4 years

BACKGROUND

Double bundle (DB) anterior cruciate ligament (ACL) reconstruction has been proposed to recreate the natural anatomy of ACL. Reconstruction of the anatomy of both the bundles of ACL has been thought to be able to restore the rotational stability of the knee joint. Nevertheless, it remains unclear whether DB reconstruction has better functional outcome than single bundle (SB) ACL reconstruction.

PURPOSE

To evaluate the clinical outcomes, patient satisfaction and manual laxity tests of knee in patients treated with DB ACL reconstruction in Indian population.

METHODS

We prospectively followed 25 patients with an isolated ACL injury operated for DB ACL reconstruction after applying the inclusion and exclusion criteria. Patients were evaluated pre-operatively and in the post-operative period at regular intervals with the minimum follow up of 4 years. Clinical stability was assessed by anterior drawer test, Lachman test and pivot shift test. Functional outcome was assessed by IKDC, Lysholm and Modified Cincinnati scores.

RESULTS

At the end of 4 years, functional outcome in terms of all subjective scores was satisfactory. Graded stability results of the Lachman, Anterior drawer and pivot shift tests were almost near to that in normal knee. No complication occurred post-operatively.

CONCLUSION

Anatomical DB ACL reconstruction seems to offer satisfactory results in terms of subjective scores and stability tests to patients with ACL tear. It has been found to be associated with no obvious complications and no failures. However a larger patient pool is desired for conclusive results.

Rotational laxity after anatomical ACL reconstruction measured by 3-D motion analysis: a prospective randomized clinical trial comparing anatomic and nonanatomic ACL reconstruction techniques

PURPOSE

To compare the ability of three different anterior cruciate ligament (ACL) reconstruction techniques to normalize rotational knee stability 1 year after ACL reconstruction. Two of these techniques are so-called anatomic techniques.

METHODS

Three different ACL reconstruction techniques were tested for their ability to normalize rotational knee stability in a prospective randomized study. Forty-seven ACL-deficient (ACLD) patients were randomized to transtibial single-bundle (SB), anatomic SB, and double-bundle ACL reconstruction. Three-dimensional motion analysis was performed preoperatively and at 1-year follow-up to evaluate tibial rotation and rotational stiffness. Motion data were captured using an eight-camera motion analysis system. Tibial rotation was determined during walking, running, and a pivoting task. Other outcome parameters were KT-1000 knee laxity measurements and the subjective outcome scores KOOS and IKDC.

RESULTS

Three-dimensional motion analysis demonstrated that the tibial internal rotation and the rotational stiffness did not differ between the ACL reconstruction techniques during walking, running, and pivoting at 1-year follow-up. Objective knee stability and subjective outcome scores did not differ between the reconstruction groups.

CONCLUSION

No significant difference in rotational stability walking, running, and pivoting was seen between anatomic and nonanatomic ACL reconstruction techniques at 1-year follow-up.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Length Changes of the Anterolateral Ligament During Passive Knee Motion: A Human Cadaveric Study

BACKGROUND

Persistent rotatory instability after anterior cruciate ligament (ACL) reconstruction may be a result of unaddressed insufficiency of the anterolateral structures. Recent publications about the anatomy of the anterolateral ligament (ALL) have led to a renewed interest in lateral extra-articular procedures, and several authors have proposed ALL reconstruction to supplement intra-articular ACL reconstruction. However, only limited knowledge about the biomechanical characteristics of the ALL exists.

PURPOSE/HYPOTHESIS

The purpose of this study was to analyze length changes of the ALL during passive knee motion. The study hypothesis was that the ALL lengthens with knee flexion and internal tibial rotation.

STUDY DESIGN

Controlled laboratory study.

METHODS

The ALL of 6 cadaveric knees was dissected. Specimens were mounted in a specifically designed test rig that allowed unconstrained passive flexion/extension movement between 0° and 90° as well as external/internal tibial rotation of 25° at various flexion angles. Highly elastic, capacitive polydimethylsiloxane strain gauges were attached to the insertion sites of the ALL. Length changes were recorded continuously at flexion angles between 0° and 90° and during internal/external tibial rotation at 0°, 15°, 30°, 45°, 60°, 75°, and 90°. All measurements were calculated as the relative length change (%) of the ALL compared with 0° of flexion and neutral rotation.

RESULTS

The mean relative length of the ALL significantly increased with increasing knee flexion (P < .001), with an estimated mean length change of +0.15% per degree. Both internal and external tibial rotation were independent determinants for length change; internal rotation significantly increased the length of the ALL (P < .001), whereas external rotation significantly decreased its length (P < .001). The mean length change with internal rotation increased with knee flexion, with a significantly greater length change at 90° compared with 0° (P = .048), 15° (P = .033), and 30° (P = .015). The maximum mean length change was +33.77% ± 9.62%, which was observed at 25° of internal rotation and 90° of flexion.

CONCLUSION

The ALL is a nonisometric structure that tensions with knee flexion and internal tibial rotation. Length changes with internal rotation were greater at higher flexion angles, with the greatest length change of the ALL observed at 90° of flexion.

CLINICAL RELEVANCE

The ALL can be considered a stabilizer against internal tibial rotation, especially at deep flexion angles. With regard to ALL reconstruction procedures, tensioning and fixation of the graft should be performed near 90° of flexion because graft tensioning near extension may cause excessive ligament strain with increasing knee flexion.

Does Double-Bundle Anterior Cruciate Ligament Reconstruction Improve Postoperative Knee Stability Compared With Single-Bundle Techniques? A Systematic Review of Overlapping Meta-analyses

PURPOSE

Multiple meta-analyses of randomized controlled trials, the highest available level of evidence, have been conducted to determine whether double-bundle (DB) or single-bundle (SB) anterior cruciate ligament reconstruction (ACL-R) provides superior clinical outcomes and knee stability; however, results are discordant. The purpose of this study was to conduct a systematic review of meta-analyses comparing SB and DB ACL-R to discern the cause of the discordance and to determine which of these meta-analyses provides the current best available evidence.

METHODS

We evaluated available scientific support for SB as compared with DB ACL-R by systematically reviewing the literature for published meta-analyses. Data on patient clinical outcomes and knee stability (as measured by KT arthrometry and pivot-shift testing) were extracted. Meta-analysis quality was judged using the Oxman-Guyatt and Quality of Reporting of Meta-analyses systems. The Jadad algorithm was then applied to determine which meta-analyses provided the highest level of evidence.

RESULTS

Nine meta-analyses were included, of which 3 included Level I Evidence and 6 included both Level I and Level II Evidence. Most studies found significant differences favoring DB reconstruction on pivot-shift testing, KT arthrometry measurement of anterior tibial translation, and International Knee Documentation Committee objective grading. Most studies detected no significant differences between the 2 techniques in subjective outcome scores (Tegner, Lysholm, and International Knee Documentation Committee subjective), graft failure, or complications. Oxman-Guyatt and Quality of Reporting of Meta-analyses scores varied, with 2 studies exhibiting major flaws (Oxman-Guyatt score <3). After application of the Jadad decision algorithm, 3 concordant high-quality meta-analyses were selected, with each concluding that DB ACL-R provided significantly better knee stability (by KT arthrometry and pivot-shift testing) than SB ACL-R but no advantages in clinical outcomes or risk of graft failure.

CONCLUSIONS

The current best available evidence suggests that DB ACL-R provides better postoperative knee stability than SB ACL-R, whereas clinical outcomes and risk of graft failure are similar between techniques.

LEVEL OF EVIDENCE

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

Intratunnel versus extratunnel autologous hamstring double-bundle graft for anterior cruciate ligament reconstruction: a comparison of 2 femoral fixation procedures

BACKGROUND

Anatomic double-bundle anterior cruciate ligament (ACL) reconstruction provides excellent results for restoring normal kinematics to the knee. Nevertheless, strong evidence supporting an ideal method for fixation of the ACL graft is lacking.

HYPOTHESIS

Intratunnel femoral fixation of the ACL graft via a cross-pin fixation technique would provide better clinical and objective results than the extratunnel femoral fixation with cortical buttons.

STUDY DESIGN

Randomized clinical trial; Level of evidence, 2.

METHODS

Seventy patients with a unilateral ACL-deficient knee were randomly assigned to 1 of 2 femoral fixation groups. Group A (35 patients) was fixed with 2 bioabsorbable Rigidfix pins, 1 cross-pin per bundle, while group B (35 patients) was secured with 1 EndoButton cortical button per bundle. All femoral tunnels were created via an anteromedial portal, and a bioabsorbable Biointrafix interference screw was used for tibial fixation for both groups. The evaluation of the patients was performed by history details, clinical examination findings, measurement of the joint laxity by KT-1000 arthrometer, and use of validated patient outcome questionnaires. Statistical analysis was carried out with Fisher exact and Mann-Whitney U tests, with P<.05 considered the cutoff level of significance.

RESULTS

At a mean follow-up of 30 months, 34 and 32 patients of group A and B, respectively, were available for evaluation. There were no statistically significant differences between the treatment groups regarding the subjective and objective outcomes, except for KT-1000 arthrometer values. The median KT-1000 value of patients in the cross-pin fixation group was 1.30 mm, while the median value in the cortical button fixation group was 1.95 mm (P<.001). Four patients with ACL grafts that were fixed with cortical buttons demonstrated failure of stability via the instrumented knee laxity testing, while patients from the other group had no failures.

CONCLUSION

Intratunnel femoral fixation of the double-bundle ACL graft from the cross-pin fixation technique provided better instrumented knee laxity results than did the extratunnel femoral fixation with cortical buttons. Future larger studies comparing these 2 techniques should be conducted to ensure the availability of stronger evidence supporting the findings of this study.

Balance ability and proprioception after single-bundle, single-bundle augmentation, and double-bundle ACL reconstruction

Purpose. The present study sought to determine the influences of single-bundle (SB), single-bundle augmentation (SBA), and double-bundle (DB) reconstructions on balance ability and proprioceptive function. Methods. 67 patients who underwent a single- or double-bundle ACL reconstruction or a SBA using multistranded autologous hamstring tendons were included in this study with a 1-year follow-up. Body sway and knee kinesthesia (using the threshold to detect passive motion test (TTDPM)) were measured to indicate balance ability and proprioceptive function, respectively. Additionally, within-subject differences in anterior-posterior stability of the tibia and lower extremity muscle strength were evaluated before and after surgery. Results. At 6 and 12 months after surgery, DB reconstruction resulted in better balance and proprioceptive function than SB reconstruction (P < 0.05). Although no significant difference was observed in balance ability or proprioceptive function between the SBA and DB reconstructions, knee stability was significantly better with SBA and DB reconstructions than SB reconstruction (P < 0.05). No significant differences were found in quadriceps and hamstrings strength among the three reconstruction techniques. Conclusions. Our findings consider that joint stability, proprioceptive function, and balance ability were superior with SBA and DB reconstructions compared to SB reconstruction at 6 and 12 months after surgery.

[Injuries of the anterior cruciate ligament in athletes]

Anterior cruciate ligament ruptures represent serious injuries for athletes which are often associated with accompanying injuries and lead to relevant kinematic alterations in the femorotibial roll-glide mechanism of the knee joint. Instability resulting in recurrent giving way events, as well as instability-related meniscal and cartilage lesions can cause functional long-term impairment that may limit the athlete's career. Anterior cruciate ligament replacement is therefore considered to be the gold standard for recovery of physical performance and to prevent secondary meniscal and cartilage damage. Continuous changes in the reconstruction of the anterior cruciate ligament have led to a variety of different methods, including graft choice, fixation devices and surgical techniques, which support the consideration of individual requirements of the athlete as well as sport-specific aspects. One of the main factors for restoring stability and the physiological kinematic roll-glide mechanism of the knee is an anatomical tunnel placement as well as a stable graft fixation in the tibia and femur. By achieving of these fundamental technical requirements an early functional rehabilitation and accelerated recovery of neuromuscular skills, strength and coordination can be achieved, so that an early return to sport activities is possible.

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.

Anatomic single- versus double-bundle ACL reconstruction: a meta-analysis

PURPOSE

To determine whether anatomic double-bundle anterior cruciate ligament (ACL) reconstruction compared to anatomic single-bundle ACL reconstruction more effectively restored antero-posterior (A-P) laxity, rotatory laxity and reduced frequency of graft rupture. Our hypothesis was that anatomic double-bundle ACL reconstruction results in superior rotational knee laxity and fewer graft ruptures due to its double-bundle tension pattern, compared with anatomic single-bundle ACL reconstruction.

METHODS

An electronic search was performed using the PubMed, EMBASE and Cochrane Library databases. All therapeutic trials written in English reporting knee kinematic outcomes and graft rupture rates of primary anatomic double- versus single-bundle ACL reconstruction were included. Only clinical studies of levels I-II evidence were included. Data regarding kinematic tests were extracted and included pivot-shift test, Lachman test, anterior drawer test, KT-1000 measurements, A-P laxity measures using navigation and total internal-external (IRER) laxity measured using navigation, as well as graft failure frequency.

RESULTS

A total of 7,154 studies were identified of which 15 papers (8 randomized controlled trials and 7 prospective cohort studies, n = 970 patients) met the eligibility criteria. Anatomic ACL double-bundle reconstruction demonstrated less anterior laxity using KT-1000 arthrometer with a standard mean difference (SMD) = 0.36 (95% CI 0.214-0.513, p < 0.001) and less A-P laxity measured with navigation (SMD = 0.29 95% CI 0.01-0.565, p = 0.042). Anatomic double-bundle ACL reconstruction did not lead to significant improvements in pivot-shift test, Lachman test, anterior drawer test, total IRER or graft failure rates compared to anatomic single-bundle ACL reconstruction.

CONCLUSION

Anatomic double-bundle ACL reconstruction is superior to anatomic single-bundle reconstruction in terms of restoration of knee kinematics, primarily A-P laxity. Whether these improvements of laxity result in long-term improvement of clinical meaningful outcomes remains uncertain.

LEVEL OF EVIDENCE

II.

Return to sport following anterior cruciate ligament reconstruction

Rates of return to pre-injury sport following anterior cruciate ligament (ACL) reconstruction are less than might be expected from standard outcome measures and there appears to be a rapid decline in sporting participation after two to three years. There are many factors that influence whether an individual will return to sport following this type of surgery. They include not only surgical details and rehabilitation, but also social and psychological factors, as well as demographic characteristics. Age is of particular importance with older patients being less likely to resume their pre-injury sport. It is important that future research clearly identify the pre-injury characteristics of the study cohort when investigating return to sport, and also that there is consistent and precise terminology used to report rates of return to sporting activities. Little is known about how to determine when it is safe to return to sport following ACL reconstruction or how to predict whether an athlete will be able to successfully return to sport. Finally, it needs to be recognised that return to sport following ACL reconstruction is associated with a risk of further injury and the development of osteoarthritis.

Double-bundle anterior cruciate ligament reconstruction: a review of literature

PURPOSE

Anterior cruciate ligament (ACL) reconstruction has been under intensive discussion and debate, although the anatomy of this ligament was resolved thoroughly almost 200 years ago. The ACL consist of two bundles, anteromedial (AM) and posterolateral (PL). The conventional single-bundle method reconstructs the AM bundle only, while the modern double-bundle technique recreates both bundles for their anatomical sites.

METHODS

An English language literature search was undertaken over the years 2000-2012 for ACL reconstruction, double-bundle versus single bundle technique. The search found 14 RCTs and two meta-analyses published to date.

RESULTS

Two of the 14 studies (14 %) showed no difference between the two reconstruction methods while the remaining majority (12 trials, 86 %) concluded that the DB technique was better than the SB method. After the DB reconstruction, rotational stability of the knee was better in seven studies (50 %) and anteroposterior stability in six (43 %). No study spoke for the single-bundle technique. In addition, with the double-bundle technique knee scores were reported to be better in five (36 %) studies, and three trials (21 %) revealed less reoperations in the double-bundle group.

CONCLUSIONS

The double-bundle ACL reconstruction technique was reported to have better or at least the same results as the conventional single-bundle method-even at a five-year follow-up. However, the majority of these studies had a rather short follow-up, and thus, longer studies are needed to confirm the true long-term results of ACL surgery. Long follow-up periods are also needed to find out whether double-bundle ACL reconstruction can eventually prevent knee osteoarthritis.