Comparison of the clinical outcome of double-bundle, anteromedial single-bundle, and posterolateral single-bundle anterior cruciate ligament reconstruction using hamstring tendon graft with minimum 2-year follow-up

Femoral Tunnel Length in Anatomical Double-Bundle Anterior Cruciate Ligament Reconstruction Is Correlated with Body Size and Knee Morphology

The purpose of this study was to reveal the correlation between anteromedial (AM) and posterolateral (PL) femoral tunnel lengths in anatomical double-bundle anterior cruciate ligament (ACL) reconstruction and body size and knee morphology. Thirty-four subjects undergoing anatomical double-bundle ACL reconstruction were included in this study. Preoperative body size (height, body weight, and body mass index) was measured. Using preoperative magnetic resonance imaging (MRI), quadriceps tendon thickness and the whole anterior-posterior length of the knee were measured. Using postoperative computed tomography (CT), axial and sagittal views of the femoral condyle were evaluated. The correlation between measured intraoperative AM and PL femoral tunnel lengths, and body size and knee morphology using preoperative MRI and postoperative CT parameters was statistically analyzed. Both AM and PL femoral tunnel lengths were significantly correlated with height, body weight, posterior condylar length, and Blumensaat's line length. These results suggest that the femoral ACL tunnel length created using a transportal technique can be estimated preoperatively by measuring the subject's body size and/or the knee morphology using MRI or CT. For clinical relevance, surgeons should be careful to create femoral tunnel of sufficient length when using a transportal technique, especially in knees of subjects with smaller body size and knee morphology. Level of evidence is III.

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.

Comparative study of functional outcomes of arthroscopic anterior cruciate ligament reconstruction using anteromedial portal and translateral all-inside technique

Background

Anterior Cruciate Ligament (ACL) injuries are common in the active population of the Armed Forces. Symptomatic instability prompts individuals to seek a cure or a sheltered appointment. Despite the increasing numbers of ACL reconstructions performed, the outcomes have not been so spectacular with only a meager percentage of our patients returning to preinjury levels of activity. With the premise that an all-inside ACL reconstruction is likely to result in better functional outcomes, the aim of this study was to compare the short-term functional outcomes of a large consecutive series of patients undergoing ACL reconstruction using the translateral all-inside ACL reconstruction technique (AI) and standard anteromedial portal technique (AM) with a minimum follow-up of one year.

Methods

A total of 240 patients with isolated ACL tear underwent ACL reconstruction via the AI or AM technique. Their preoperative and postoperative scores were compared to look for any significant differences in functional outcomes.

Results

The two groups were matched for age, BMI, mechanism of injury, and interval from injury to surgery. There was no difference in their preoperative scores. Postoperatively, although there were significant improvements across both groups, there was no significant difference between the groups at any point of time.

Conclusion

The AI technique has garnered interest in recent literature in addressing ACL injuries. This study found no discernible benefit of the AI technique when compared to the AM technique in terms of functionality following an ACL reconstruction at any point of time up to 1 year following surgery.

Size Comparison of the Cadaveric Anterior Cruciate Ligament Midsubstance Cross-Sectional Area and the Cross-Sectional Area of Semitendinosus Double-Bundle Anterior Cruciate Ligament Reconstruction Autografts in Surgery

The purpose of this study was to compare the cadaveric midsubstance cross-sectional anterior cruciate ligament (ACL) area and the cross-sectional semitendinosus (ST) double-bundle ACL autograft area in surgery. Thirty-nine nonpaired formalin-fixed cadaveric knees and 39 subjects undergoing ST double-bundle ACL reconstruction were included in this study. After soft tissue resection, cadaveric knees were flexed at 90 degrees, and the tangential line of the femoral posterior condyles was marked and sliced on the ACL midsubstance. The cross-sectional ACL area was measured using Image J software. In the patients undergoing ACL surgery, the harvested ST was cut and divided into anteromedial (AM) bundle and posterolateral (PL) bundle. Each graft edge diameter was measured by a sizing tube, and the cross-sectional graft area was calculated: (AM diameter/2)2 × 3.14 + (PL diameter/2)2 × 3.14. Statistical analysis was performed for the comparison of the cross-sectional area between the cadaveric ACL midsubstance and the ST double-bundle ACL autografts. The cadaveric midsubstance cross-sectional ACL area was 49.0 ± 16.3 mm2. The cross-sectional ST double-bundle autografts area was 52.8 ± 7.6 mm2. The ST double-bundle autograft area showed no significant difference when compared with the midsubstance cross-sectional ACL area. ST double-bundle autografts were shown to be capable of reproducing the midsubstance cross-sectional ACL area.

Single Bundle Versus Double Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) tear is considered as one of the most common sport-related musculoskeletal injuries. Double bundle (DB) and single bundle (SB) surgical techniques has been widely adopted for ACL reconstruction. This systematic review aimed to provide updated evidence by comparing the short-term, mid-term, and long-term knee stability and functional outcomes of DB and SB reconstruction techniques.

Methods

We searched Medline, Web of Science, and CENTRAL. We have selected randomized controlled trials (RCTs) that compared DB and SB ACL reconstruction techniques for primary isolated ACL tear. We have assessed the following outcomes: pivot shift test, Lachman test, KT-1000/2000 knee ligament arthrometer, Lysholm knee function score, Tegner activity score, and graft failure. We have used the standardized mean difference (SMD) was to summarize the continuous outcomes while risk ratio (RR) was used to summarize the dichotomous outcomes.

Results

A total of 34 RCTs that enrolled 2,992 participants deemed eligible. Overall, DB showed significantly better outcomes in terms of pivot shift test (RR = 0.61, 95% confidence interval (CI) 0.49-0.75), Lachman test (RR = 0.77, 95% CI 0.62 to 0.95), and KT 1000/2000 arthrometer (SMD = - 0.21, 95% CI - 0.34 to - 0.08). No discernible difference was found between DB and SB techniques in the overall Lysholm score (SMD = 0.12, 95% CI - 0.03 to 0.27), Tegner score (SMD = 0.03, 95% CI - 0.17 to 0.24), or graft failure rate (RR = 0.78, 95% CI 0.33 to 1.85).

Conclusions

Our review suggests that DB ACL reconstruction technique shows significantly better knee stability and functional outcomes than SB at short-term follow-up. However, both techniques exhibit similar outcomes at mid-term and long-term follow-up.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00718-0.

Radiological maturation and clinical results of double-bundle and single-bundle anterior cruciate ligament reconstruction. A 5-year prospective case-controlled trial

INTRODUCTION

The aim of the study was to make a prospective comparison of the radiological and clinical outcomes of patients undergoing single-bundle and double-bundle anterior cruciate ligament (ACL) reconstruction.

METHOD

This prospective, case-controlled study included 65 patients, separated into 2 groups as 33 patients undergoing single bundle (SB), and 32 patients undergoing double bundle (DB) ACL reconstruction. The patients were evaluated clinically using the International Knee Documentation Committee (IKDC) and the Lysholm knee scores. Stability was evaluated with the KT-1000 Arthrometer Measurement, the Lachman and pivot shift tests. Magnetic resonance images (MRI) at 1 and 5 years postoperatively were evaluated by a musculoskeletal radiologist. All the operations were performed by a single surgeon and the clinical evaluations were made by an independent researcher.

RESULTS

Evaluation was made of a total of 53 patients (SB: 28, DB: 25). No statistically significant difference was determined between the groups regarding the postoperative IKDC and Lysholm scores. The pivot shift tests were negative in the DB group and positive in two patients of the SB group. The Lachman test was negative in all the patients. No significant difference was determined between the groups. No statistically significant difference was determined between the two groups in respect of the arthrometer measurements. In the SB group, revision surgery was performed in two patients due to graft failure. No graft failure findings were determined in the DB group, and no statistically significant difference was determined between the groups in respect of graft failure. On the MRIs taken at 1 year postoperatively, the ACL was seen to be hyperintense in 16 patients in the DB group and 6 patients in the SB group (p = 0.004). On the 5-year MRIs, ACL hypointensity could not be seen in three patients of the SB group and two of the DB group, with no difference determined between the groups (p > 0.05).

CONCLUSION

In the 5-year follow-up period, no difference was determined between patients undergoing SB ACL reconstruction and those undergoing DB ACL reconstruction regarding clinical scores, knee stability, and MRI findings, but graft maturation occurs later the patients undergoing DB reconstruction.

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.

Transportal versus all-inside techniques of anterior cruciate ligament reconstruction: a systematic review

Background

Transportal (TP) and all-inside techniques (AIT) are the most commonly used anterior cruciate ligament (ACL) reconstruction procedures in current clinical practice. However, there is an ongoing debate over which procedure is superior. Therefore, the purpose of this systematic review was to evaluate and compare the clinical outcomes and complications of these two techniques to propose recommendations for future application. Our primary hypothesis was that AIT is a superior ACLR technique compared to TP.

Methods

A systematic literature review, using PRISMA guidelines, was conducted using PubMed, Medline, Google Scholar, and EMBASE, up to February 2021 to identify studies focusing on AIT and TP techniques of ACL reconstruction. We excluded animal experiments, cadaveric studies, retrospective studies, case reports, technical notes, and studies without quantitative data. Patients’ characteristics, surgical technical features, along with postoperative follow-up and complications were extracted and reported accordingly. Methodological quality of the included studies was assessed using the Modified Coleman Methodology Score (MCMS).

Results

A total of 44 studies were selected for this review, of which four were comparative studies. A total of 923 patients underwent AIT and 1678 patients underwent the TP technique for ACLR. A single semitendinosus graft was commonly used in the AIT compard to combined semitendinosus and gracilis graft in the TP group. The postoperative increase in International Knee Documentation Committee (IKDC), Lysholm, KT-1000, and Short Form-12 (physical and mental) scores were similar in the AIT group and the TP group. Contrastingly, the VAS pain score was significantly lower in the AIT group compared to the TP group. Furthermore, the pooled complication rates from all studies were similar between the two groups (AIT: 54 patients, 8.26% vs. PT: 55 patients, 6.62%). However, the four studies that prospectively compared AIT and TP techniques showed lesser complications in the AIT group than the TP group.

Conclusion

Since the future trend in orthopedic surgery is toward less invasive and patients’ satisfaction with good outcomes, AIT is a good alternative method considering preserving bony tissue and gracilis tendon with less post-operative pain, along with more knee flexor strength and equal outcomes compared to conventional ACL reconstruction surgery.

Level of Evidence II.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02872-x.

Comparing post-operative pain between single bundle and double bundle anterior cruciate ligament reconstruction: a retrospective study

Background

In anterior cruciate ligament (ACL) reconstruction, the clinical outcome and level of post-operative pain are important factors. To date there have been no studies evaluating differences in post-operative pain between single bundle and double bundle ACL reconstruction with a hamstring graft.

Hypothesis/purpose

We hypothesized that post-operative pain in single bundle ACL reconstruction would be less than in double bundle ACL reconstruction. This study was to compare post-operative pain between patients undergoing single bundle versus double bundle ACL reconstruction.

Study design

Cohort study.

Methods

This was a retrospective study comparing post-operative pain scores between single bundle and double bundle ACL reconstruction. Each patient was given our standard regimen of oral diclofenac (25 mg/tab) three times per day and paracetamol (500 mg/tab) six times per day for 1 day post-operatively. If the patient complained of moderate to severe pain (pain numeric rating scale (PNRS) > 3), 3 mg of morphine was injected intravenously every 3 h for 24 h and 1 mg of morphine as a rescue medication every 1 h for 24 h. PNRS and morphine consumption were recorded at 4-h intervals for 24 h.

Results

209 patients were included in this study of whom 102 and 107 patients received single bundle and double bundle ACL reconstruction, respectively. The average post-operative pain scores of the single bundle group were lower at all time points. Linear mixed effect regression analyses showed that the single bungle group had lower post-operative pain than the double bundle group after adjusting for confounders (beta = − 0.45; 95% CI = − 0.838, − 0.062) but there was no statistically significant difference between numbers of bundle ACL reconstruction with regard to morphine consumption.

Conclusion

Single bundle ACL reconstruction had significantly lower post-operative pain scores than double bundle ACL reconstruction.

Clinical relevance

Double bundle ACL reconstruction results in higher post-operative pain, which may slow the start of rehabilitation and reduce patient satisfaction. In middle-aged adult patients with low-demand activities, we suggest performing a single bundle ACL reconstruction.

Subjective assessment reported by patients shows differences between single-bundle and double-bundle anterior cruciate ligament reconstruction, systematic review and meta-analysis

To determine the functional recovery, active reincorporation, and anteroposterior and rotational stability of patients undergoing anterior cruciate ligament (ACL) reconstruction using arthroscopy techniques with simple-bundle (SB) or double-bundle (DB). The following databases were searched: PubMed, Embase (Elsevier platform), the Cochrane Central Register of Controlled Trials (Wiley platform), Web of Science, and CINAHL. Level I and II studies involving anterior cruciate ligament arthroscopy were included in the search. Records were screened by title and abstract and assessed the risk of bias of selected studies. Meta-analyses using RevMan 5.3 software were conducted on the following outcomes: knee functionality, objective measurements of knee stability, rotational knee stability and knee anterior stability, sports reincorporation, and subjective assessments. Twenty-four studies of patients undergoing ACL reconstruction were included in the qualitative and quantitative synthesis (1707 patients) for Lysholm score, Subjective International Knee Documentation Committee (IKDC) score, Tegner score, KT-1000/2000, Lachman test, Objective IKDC score, and Pivot-Shift test. A return to pre-injury level showed a significant decrease in the Lysholm score (mean difference, - 0.99; 95% CI - 1.71 to - 0.40; P = 0.007) and Tegner score (mean difference, - 0.07; 95% CI, - 0.13 to - 0.01; P = 0.02) at DB reconstruction, similar to the knee functionality outcome of the subjective IKDC score (mean difference - 1.42; 95% CI - 2.46 to - 0.38; P = 0.007). There is no clear or significant difference in clinical stability and knee function or in sports incorporation with the true difference occurring in the subjective assessment.

Stress radiography at 30° of knee flexion is a reliable evaluation tool for high-grade rotatory laxity in complete ACL-injured knees

PURPOSE

To evaluate the diagnostic value of stress radiography and determine the cutoff values for high-grade anterolateral rotatory laxity in complete anterior cruciate ligament (ACL)-deficient knees at different positions.

METHODS

Forty-two patients with complete ACL rupture (group 1) and 37 normal subjects (group 2) were prospectively enrolled. The amount of anterior translation in the medial (MM) and lateral (LL) distance compartments and the difference between them (LL-MM distance) were measured using stress radiography at 30°, 45°, 60°, and 90° positions. The area under the receiver operating characteristic curve (AUC) was assessed for the presence of a high-grade (grade > 2) pivot shift.

RESULTS

The MM and LL distances in group 1 were significantly different at 30° and 45° positions (P < 0.05). The AUC of the MM (AUC, 0.903) and LL (AUC, 0.901) distances at the 30° position was significantly higher than that of the other positions (P = 0.000); however, the cutoff values were different to diagnose ACL injury (MM vs. LL, 3.1 mm vs. 5.4 mm). A 2.1-mm cutoff for the LL-MM distance showed 78.4% sensitivity and 90.3% specificity for detecting the presence of a high-grade pivot shift (AUC = 0.905, P = 0.000).

CONCLUSION

The cutoff values of stress radiography differed according to anatomical references and knee flexion positions. Stress radiography of a 2.1 mm difference in LL-MM distance at 30° of knee flexion can be a reliable method for high-grade rotatory laxity in complete ACL-injured knees.

LEVEL OF EVIDENCE

Level 1, diagnostic study.

Eight-year results of transtibial nonanatomic single-bundle versus double-bundle anterior cruciate ligament reconstruction: Clinical, radiologic outcomes and survivorship

PURPOSE

To compare the long term outcomes of transtibial nonanatomic single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Between January 2008 and September 2010, we retrospectively evaluated 377 patients who underwent primary ACL reconstruction and who were available at 8 years of follow-up. Patients who received transtibial nonanatomic SB ACL reconstruction ( n = 263) were assigned to group SB and DB ACL reconstruction ( n = 114) to group DB. The patients were assessed with the International Knee Documentation Committee (IKDC), the Lysholm scores, Tegner activity score, knee joint stability tests, and patellofemoral osteoarthritis (OA) findings using the Kellgren-Lawrence (K-L) classification. Contralateral ACL (CACL) injury was also evaluated.

RESULTS

Thirteen patients underwent revision ACL surgery during the follow-up. Ultimately, 256 patients in group SB and 108 patients in group DB were available at the 8-year follow-up. At final follow-up, the IKDC subjective score ( p = 0.04) and Lysholm score ( p = 0.02) showed significantly superior results in group DB compared to group SB. However, there was no significant difference of Tegner activity score ( p = 0.30), range of motion ( p = 0.81), and knee joint stability tests. There was significant progression of patellofemoral OA between preoperative and final follow-up in ipsilateral knee of both groups but not significant progression in contralateral knee. However, there was no significant difference between the two groups at the follow-up. There were 2.7% ipsilateral ACL graft failure in group SB, compared with 5.2% in group DB ( p = 0.12) and 6.4% CACL tear in group SB, compared with 5.2% in group DB ( p = 0.65). The mean survivorship of ACL graft was 9.47 ± 0.05 years (95% confidence interval (CI), 9.36-9.58) in group SB and 9.87 ± 0.16 years (95% CI, 9.54-10.20) in group DB, and there was no significant difference ( p = 0.25).

CONCLUSION

DB ACL reconstruction resulted in significantly better clinical IKDC subjective scores and Lysholm scores. However, most of the differences in clinical scores were small, and the clinical relevance of this difference is unknown. In addition, there was no significant difference in Tegner activity score, knee joint stability tests, patellofemoral OA, and survivor rate of the ACL graft and CACL after reconstruction after a minimum of 8-year follow-up. Level of Evidence: Cohort study; level of evidence, 3.

Over-the-top ACL reconstruction restores anterior and rotatory knee laxity in skeletally immature individuals and revision settings

PURPOSE

To investigate the objective outcomes following anterior cruciate ligament reconstruction (ACLR) with the over-the-top (OTT) technique.

METHODS

Thirty-five ACL-deficient patients with mean follow-up of 2.2 years were retrospectively reviewed. This included 14 skeletally immature individuals (age: 14 ± 1 years) who underwent primary OTT ACLR (adolescent group) and 21 skeletally mature individuals (age: 25 ± 8 years) who underwent OTT revision ACLR (revision group). The tibial tunnel was created at the anatomic position for all cases. No lateral extra-articular tenodesis was performed. Before and after surgery, the side-to-side difference (SSD) in anterior laxity was measured using KT-1000 arthrometer. Lachman and pivot-shift tests were assessed according to IKDC grade. The graft failure rate was assessed.

RESULTS

The post-operative SSD in anterior laxity was significantly reduced in the adolescent (pre-op, 3.9 ± 1.8 mm; post-op, 1.2 ± 0.8 mm; p = 0.040) and revision groups (pre-op, 4.2 ± 1.7 mm; post-op, 1.2 ± 1.4 mm; p < 0.001). Postoperative knee laxity measured by Lachman and pivot-shift tests were also significantly improved in both groups. Graft rupture occurred in two patients in the adolescent group (14.3%), and one patient in the revision group (4.8%).

CONCLUSION

ACLR with the OTT technique restored anterior and rotatory knee laxity in skeletally immature individuals and in revision settings. This one-step procedure may be a good option for skeletally immature individuals and revision settings.

LEVEL OF EVIDENCE

IV.

The Anterolateral Structure of the Knee Does Not Affect Anterior and Dynamic Rotatory Stability in Anterior Cruciate Ligament Injury: Quantitative Evaluation With the Electromagnetic Measurement System

BACKGROUND

The biomechanical function of the anterolateral structure (ALS), which includes the anterolateral joint capsule and anterolateral ligament (ALL), remains a topic of debate.

HYPOTHESIS

The ALS contributes to knee joint stability during the Lachman test and the pivot-shift test in anterior cruciate ligament (ACL)-deficient knees.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fourteen fresh-frozen hemipelvis lower limbs were used. For 7 specimens, the anterior one-third of the ALS and the residual ALS were cut intra-articularly with a radiofrequency device. Subsequently, the ACL was cut arthroscopically. For the other 7 specimens, the ACL was cut first, followed by the anterior one-third of the ALS and the residual ALS intra-articularly. During the procedures, the iliotibial band (ITB) was kept intact. At each condition, the anterior tibial translation (ATT) during the manual Lachman test and the acceleration of posterior tibial translation (APT) and the posterior tibial translation (PTT) during the manual pivot-shift test were measured quantitatively with an electromagnetic measurement system. The mean values of those parameters were compared among 6 groups (ACL intact, one-third ALS cut, all ALS cut, ACL cut, ACL/one-third ALS cut, and ACL/all ALS cut).

RESULTS

The mean ATTs during the Lachman test and the mean APTs and PTTs in the ACL-cut conditions (ACL cut, ACL/one-third ALS cut, and ACL/all ALS cut) were significantly larger than those under the ACL-intact conditions (ACL intact, one-third ALS cut, all ALS cut) (P < .01). However, no statistically significant differences were observed among the intact, one-third ALS-cut, and all ALS-cut conditions, within the ACL-intact or ACL-cut conditions.

CONCLUSION

Intra-articular dissection of the ALS did not increase the ATT during the Lachman test or the APT and PTT during the pivot-shift test under the intact condition of the ITB, regardless of the integrity of the ACL. When the ITB is intact, the ALS does not have a significant role in either anterior or dynamic rotatory knee stability, while the ACL does.

CLINICAL RELEVANCE

Recent growing interest about ALL reconstruction or ALS augmentation may not have a large role in controlling either anterior or dynamic rotatory knee instability in isolated ACL-deficient knees.

Laser-guided transtibial technique improved single-bundle reconstruction of anterior cruciate ligament

Background

The transtibial tunnel technique achieves equal length reconstruction of the anterior cruciate ligament (ACL). This study aimed to investigate whether transtibial tunnel technique can achieve anatomical reconstruction of ACL.

Methods

For 25 corpses, the anterior soft tissue of the knee joint was detached so that the ligamentous surface was fully exposed, then the knee joint was fixed at 90° with an external fixator and the anterior cruciate ligament was removed. Double-sided laser technology was used to establish spatial conformation of ACL.

Results

The male to female ratio of the subjects was 19:6, with an average age of 59.52 ± 11.13 years. Patellar tendon length was 35.23 ± 5.10 mm, tibial eminence length and width was 15.75 ± 2.44 and 7.80 ± 1.28 mm, respectively, and femoral attachment length and width was 15.40 ± 2.17 and 8.97 ± 1.61 mm, respectively. When the flexion turned 90°, the tibial tunnel length was 31.83 ± 4.09 mm and the distance to the tibial plateau, patellar tendon, and medial collateral ligament was 16.33 ± 4.56, 10.79 ± 5.85, and 23.12 ± 5.99 mm, respectively.

Conclusions

With the aid of double-sided laser technology, transtibial tunnel technique can safely achieve single-bundle reconstruction of ACL.

A meta-analysis on anterior cruciate ligament reconstruction: Is modified transtibial technique inferior to independent drilling techniques?

This report respectively compared the standard transtibial (sTT) technique to the independent drilling (ID) techniques applied to anterior cruciate ligament (ACL) reconstruction. It also made a comparison between the clinical results of the modified transtibial (mTT) technique and of the ID techniques. Prospective studies on transtibial (TT) and ID techniques for ACL reconstruction were retrieved from several databases and a subgroup analysis was performed to compare the sTT technique with the ID techniques and the mTT with the ID techniques. Furthermore, comparison of the Lachman test, pivot-shift test, International Knee Documentation Committee (IKDC) subjective and objective evaluations, Lysholm score and Tegner activity scale were conducted. This report included 12 clinical studies that involved 681 patients having received ACL reconstruction. The study results indicated that in comparison between the sTT and ID techniques, the ID techniques outperformed the sTT technique in the IKDC subjective score (P=0.01) and laxity (P=0.0004). However, there was no significant difference in the IKDC objective score (P=0.34), pivot-shift test (P=0.24), Lachman test (P=0.21), Lysholm score (P=0.14) and Tegner activity scale (P=0.66). The comparison between the new mTT technique and the ID techniques suggested no significant difference in the IKDC objective and subjective scores (P=0.86), laxity (P=0.38), pivot-shift test (P=0.66), Lachman test (P=0.10), Lysholm score (P=0.10) and Tegner activity scale (P=0.55). Compared to the sTT technique, the mTT and ID techniques are more suitable for ACL reconstruction because they can present better subjective feelings. Moreover, considering that the TT technique is familiar to surgeons and the mTT technique can bring favorable subjective feelings and objective clinical outcomes, the mTT technique shows greater utilization potential.

Stress distribution is deviated around the aperture of the femoral tunnel in the anatomic anterior cruciate ligament reconstruction

PURPOSE

Final tunnel location in the anterior cruciate ligament (ACL) reconstruction is unpredictable due to tunnel widening and/or transposition. The mechanical stress around the tunnel aperture seems to be a major factor but is not fully investigated. The purpose of this study was to measure the stress from the ACL graft around the tunnel aperture when the ACL graft tension reaches its peak.

METHODS

Six cadaveric knees were used. Single-bundle ACL reconstruction was performed using a hamstrings graft. Both femoral and tibial tunnels were created at the centre of the original ACL footprint. A 7-mm-internal-diameter aluminium cylinder with pressure sensors was placed in the femoral tunnel. Hamstrings graft with a microtension sensor was inserted. After fixation, passive extension-flexion was performed while monitoring the tunnel aperture pressure and the graft tension simultaneously. The pressure on the femoral tunnel aperture when the ACL graft tension reach its peak was compared between four directions.

RESULTS

The ACL graft tension peaked (67 ± 49 N) at full extension (-5.8 ± 4.1°). Pressure at the femoral tunnel aperture was different between different directions (p < 0.01). Distal part had significantly larger pressure (1.7 ± 1.3 MPa) than the other directions (p < 0.01). Second largest pressure was carried in the anterior part (0.6 ± 0.5 MPa), followed by proximal and posterior parts (0.4 ± 0.3, 0.2 ± 0.2 MPa respectively).

CONCLUSION

The stress distribution at the femoral tunnel aperture is not equal in different directions, while the distal part dominantly bears the stress from the ACL graft. Surgeons should pay close attention to the distal edge of the femoral tunnel which should be inside the anatomic ACL footprint eventually.

Double-Bundle Versus Single-Bundle Anterior Cruciate Ligament Reconstruction: A Prospective Randomized Study With 10-Year Results

BACKGROUND

A long-term follow-up comparing double-bundle and single-bundle techniques for anterior cruciate ligament (ACL) reconstruction has not been reported before.

HYPOTHESIS

Double-bundle ACL reconstruction may have fewer graft ruptures, lower rates of osteoarthritis (OA), and better stability than single-bundle reconstruction.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Ninety patients were randomized for double-bundle ACL reconstruction with bioabsorbable screw fixation (DB group; n = 30), single-bundle ACL reconstruction with bioabsorbable screw fixation (SBB group; n = 30), and single-bundle ACL reconstruction with metallic screw fixation (SBM group; n = 30). Evaluation methods consisted of a clinical examination, KT-1000 arthrometer measurements, International Knee Documentation Committee (IKDC) and Lysholm knee scores, and a radiographic examination of both the operated and contralateral knees.

RESULTS

Eighty-one patients (90%) were available at the 10-year follow-up. Eleven patients (1 in the DB group, 7 in the SBB group, and 3 in the SBM group) had a graft failure during the follow-up and went on to undergo revision ACL surgery ( P = .043). In the remaining 70 patients at 10 years, no significant group differences were found in the pivot-shift test findings, KT-1000 arthrometer measurements, or knee scores. The most OA findings were found in the medial compartment of the knee, with 38% of the patients in the operated knee and 28% of the patients in the contralateral nonoperated knee. However, no significant group difference was found. The most severe OA changes were in the patients who had the longest delay from the primary injury to ACL reconstruction ( P = .047) and in the patients who underwent partial meniscal resection at the time of ACL reconstruction ( P = .024).

CONCLUSION

Double-bundle ACL reconstruction resulted in significantly fewer graft failures than single-bundle ACL reconstruction during the follow-up. Knee stability and OA rates were similar at 10 years. The most severe OA changes were found in the patients who had the longest delay from the primary injury to ACL reconstruction and in the patients who underwent partial meniscal resection at the time of ACL reconstruction.

Comparison Between Intra- and Extra-articular Tension of the Graft During Fixation in Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate the tension deprivation through the tunnels with and without preconditioning at the time of fixation, and the influences of cyclic loading and pretensioning on graft tension in anatomic single bundle anterior cruciate ligament (ACL) reconstruction using a hamstring tendon.

METHODS

Nine fresh-frozen cadaveric knees underwent anatomic ACL reconstruction using hamstring grafts. Each specimen was examined to ensure that there was no severe osteoarthritic change, ligament insufficiency, or torn menisci by manual and arthroscopic evaluation. Applied graft tension was measured at the tibial tunnel outlet using a graft tensor with a load cell. Intra-articular graft tension was evaluated by using an originally developed microforce sensor, which was sutured into the graft. Both tensions were simultaneously measured just after initial tensioning under 3 different conditions: condition 1, just after initial tensioning of 20 N at 20° of knee flexion without preconditioning; condition 2, after the same initial tensioning following 5 rounds of passive cyclic flexion-extension movement; and condition 3, after the same initial tensioning following 5 minutes of static pretensioning of 20 N.

RESULTS

The intra-articular tension was 12.7 ± 5.3 N in condition 1, 12.0 ± 4.8 N in condition 2, and 13.5 ± 4.8 N in condition 3. In these 3 conditions, intra-articular graft tension was significantly lower than the applied tension of around 20 N (no pretension: P = .009, cyclic pretension: P = .004, static pretension: P = .008), with no difference among the 3 conditions (P = .82).

CONCLUSIONS

The intra-articular graft tension was significantly lower than the applied tension from the outside of the joint, even after cyclic loading and pretensioning.

CLINICAL RELEVANCE

It is difficult to evaluate the intra-articular graft tension precisely on the basis of the extra-articular tension at time zero in ACL reconstruction.

Clinical outcomes and biomechanical analysis of posterolateral bundle augmentation in patients with partial anterior cruciate ligament tears

PURPOSE

To examine the clinical and biomechanical results of posterolateral (PL) augmentation to reconstruct damaged PL bundle while preserving the less-damaged anteromedial bundle for partial anterior cruciate ligament (ACL) tears in comparison with double-bundle ACL reconstruction.

METHODS

Sixteen patients who underwent PL augmentation for partial ACL tears (Group P) and 37 patients who underwent double-bundle ACL reconstructions for complete ACL tears were examined (Group D). Anterior tibial translation (ATT) was evaluated using the KT-1000 arthrometer. ATT during the Lachman test and acceleration of posterior tibial translation (APT) during the pivot shift test were evaluated using an electromagnetic measurement system (EMS). Clinical outcomes were evaluated using the Lysholm score. Second-look arthroscopy was performed 1 year after surgery.

RESULTS

The mean postoperative Lysholm scores were 91.7 ± 12.2 and 94.6 ± 7.2 in Groups P and D, respectively, and there was no statistically significant difference between the two groups. The mean side-to-side difference of ATT on the KT-1000 was significantly improved in both Groups P and D. In the EMS analysis, the mean side-to-side difference of ATT and the mean APT were significantly improved in both Groups P and D. There was no significant difference in the second-look evaluation between the two groups.

CONCLUSIONS

The clinical and biomechanical outcomes of PL augmentation were satisfactorily comparable to those of double-bundle ACL reconstruction. PL augmentation could be a useful treatment option for patients with partial ACL tears.

LEVEL OF EVIDENCE

IV.

Combination of platelet-rich plasma and bone marrow mesenchymal stem cells enhances tendon-bone healing in a rabbit model of anterior cruciate ligament reconstruction

Background

The objective of this study was to investigate the potency of platelet-rich plasma (PRP) combined with bone marrow mesenchymal stem cells (BMSCs) to promote tendon–bone healing in a rabbit model.

Methods

In the in vitro study, the effects of PRP on osteogenic induction of BMSCs were analysed. Later, PRP with or without BMSCs was used in the rabbit model of anterior cruciate ligament reconstruction. Specimens were harvested 8 weeks postoperatively to evaluate tendon–bone healing by histology, radiology, and biomechanical testing.

Results

The in vitro study revealed that collagen I, osteocalcin, and osteopontin expression was higher in BMSCs co-cultured with PRP for 14 days. The in vivo study revealed a more mature tendon–bone interface using light microscopy, a more newly formed bone at the bone tunnel walls detected by micro-computed tomography, and a significantly higher failure load as assessed by biomechanical testing in the BMSC + PRP group than in the control and PRP groups.

Conclusions

These results indicate that the combination of PRP and BMSCs promotes tendon–bone healing and has potential for clinical use.

Electronic supplementary material

The online version of this article (doi:10.1186/s13018-016-0433-7) contains supplementary material, which is available to authorized users.

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.

A systematic review of single- versus double-bundle ACL reconstruction using the anatomic anterior cruciate ligament reconstruction scoring checklist

PURPOSE

The aim of this systematic review was to apply the anatomic ACL reconstruction scoring checklist (AARSC) and to evaluate the degree to which clinical studies comparing single-bundle (SB) and double-bundle (DB) ACL reconstructions are anatomic.

METHODS

A systematic electronic search was performed using the databases PubMed (MEDLINE), EMBASE and Cochrane Library. Studies published from January 1995 to January 2014 comparing SB and DB ACL reconstructions with clinical outcome measurements were included. The items from the AARSC were recorded for both the SB and DB groups in each study.

RESULTS

Eight-thousand nine-hundred and ninety-four studies were analysed, 77 were included. Randomized clinical trials (29; 38%) and prospective comparative studies (29; 38%) were the most frequent study type. Most studies were published in 2011 (19; 25%). The most commonly reported items for both SB and DB groups were as follows: graft type (152; 99%), femoral and tibial fixation method (149; 97% respectively), knee flexion angle during graft tensioning (124; 8%) and placement of the tibial tunnel at the ACL insertion site (101; 66%). The highest level of documentation used for ACL tunnel position for both groups was often one dimensional, e.g. drawing, operative notes or o'clock reference. The DB reconstruction was in general more thoroughly reported. The means for the AARSC were 6.9 ± 2.8 for the SB group and 8.3 ± 2.8 for the DB group. Both means were below a proposed required minimum score of 10 for anatomic ACL reconstruction.

CONCLUSIONS

There was substantial underreporting of surgical data for both the SB and DB groups in clinical studies. This underreporting creates difficulties when analysing, comparing and pooling results of scientific studies on this subject.

Single-Bundle Versus Double-Bundle Anterior Cruciate Ligament Reconstruction: A Comparative 2-Year Follow-up

PURPOSE

To compare anatomic single-bundle (SB) versus double-bundle (DB) anterior cruciate ligament (ACL) reconstruction and to determine possible differences in clinical outcomes.

METHODS

In this prospective randomized study, 64 patients were divided into 2 equal groups. Anatomic SB and DB ACL reconstructions were performed using hamstring tendons. A follow-up examination 2 years after surgery comprised International Knee Documentation Committee (IKDC) 2000 assessment, Laxitester (ORTEMA Sport Protection, Markgröningen, Germany) measurement of anteroposterior translation regarding rotational stability, and radiographic evaluation. Statistical analysis and power calculation were performed (P < .05).

RESULTS

We examined 62 patients at a mean of 26 months (range, 23.3 to 32.7 months) after surgery. IKDC subjective and objective scores showed no significant differences when both groups were compared. The Laxitester measurements showed no significant differences regarding anteroposterior translation in the neutral position, internal rotation, and external rotation. However, there was a significant improvement in rotational laxity in external rotation in the DB group (P = .02). No differences were seen between the groups regarding osteoarthritic changes and tunnel widening.

CONCLUSIONS

There were no differences in IKDC subjective and objective scores between patients who underwent anatomic SB ACL reconstruction and those who underwent anatomic DB ACL reconstruction.

LEVEL OF EVIDENCE

Level I, prospective, randomized controlled clinical trial.

Quantitative comparison of the pivot shift test results before and after anterior cruciate ligament reconstruction by using the three-dimensional electromagnetic measurement system

PURPOSE

Tibial acceleration during the pivot shift test is a potential quantitative parameter to evaluate rotational laxity of anterior cruciate ligament (ACL) insufficiency. However, clinical application of this measurement has not been fully examined. This study aimed to measure and compare tibial acceleration before and after ACL reconstruction (ACLR) in ACL-injured patients. We hypothesized tibial acceleration would be reduced by ACLR and tibial acceleration would be consistent in the same knee at different time points.

METHODS

Seventy ACL-injured patients who underwent ACLR were enrolled. Tibial acceleration during the pivot shift test was measured using an electromagnetic measurement system before ALCR and at the second-look arthroscopy 1 year post-operatively. Tibial acceleration was compared to clinical grading and between ACL-injured/ACL-reconstructed and contralateral knees.

RESULTS

Pre-operative tibial acceleration was increased stepwise with the increase in clinical grading (P < 0.01). Tibial acceleration in ACL-injured knee (1.9 ± 1.2 m/s(2)) was larger than that in the contralateral knee (0.8 ± 0.3 m/s(2), P < 0.01), and reduced to 0.9 ± 0.3 m/s(2) post-operatively (P < 0.01). There was no difference between ACL-reconstructed and contralateral knee (n.s.). Tibial acceleration in contralateral knees was consistent pre- and post-operatively (n.s.).

CONCLUSION

Tibial acceleration measurement demonstrated increased rotational laxity in ACL-injured knees and its reduction by ALCR. Additionally, consistent measurements were obtained in ACL-intact knees at different time points. Therefore, tibial acceleration during the pivot shift test could provide quantitative evaluation of rotational stability before and after ACL reconstruction.

LEVEL OF EVIDENCE

III.

High Variability in Outcome Reporting Patterns in High-Impact ACL Literature

BACKGROUND

ACL (anterior cruciate ligament) reconstruction is one of the most commonly performed and studied procedures in modern sports medicine. A multitude of objective and subjective patient outcome measures exists; however, nonstandardized reporting patterns of these metrics may create challenges in objectively analyzing pooled results from different studies. The goal of this study was to document the variability in outcome reporting patterns in high-impact orthopaedic studies of ACL reconstruction.

METHODS

All clinical studies pertaining to ACL reconstruction in four high-impact-factor orthopaedic journals over a five-year period were reviewed. Biomechanical, basic science, and imaging studies were excluded, as were studies with fewer than fifty patients, yielding 119 studies for review. Incorporation of various objective and subjective outcomes was noted for each study.

RESULTS

Substantial variability in reporting of both objective and subjective measures was noted in the study cohort. Although a majority of studies reported instrumented laxity findings, there was substantial variability in the type and method of laxity reporting. Most other objective outcomes, including range of motion, strength, and complications, were reported in <50% of all studies. Return to pre-injury level of activity was infrequently reported (24% of studies), as were patient satisfaction and pain assessment following surgery (8% and 13%, respectively). Of the patient-reported outcomes, the International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores were most often reported (71%, 63%, and 42%, respectively).

CONCLUSIONS

Substantial variability in outcome reporting patterns exists among high-impact studies of ACL reconstruction. Such variability may create challenges in interpreting results and pooling them across different studies.

Dynamic Effect of Quadriceps Muscle Activation on Anterior Tibial Translation After Single-Bundle and Double-Bundle Anterior Cruciate Ligament Reconstruction

PURPOSE

To examine differences in anterior tibial translation in 3 groups: single-bundle anterior cruciate ligament (ACL)-reconstructed, double-bundle ACL-reconstructed, and ACL-intact knees under gradual dynamic quadriceps muscle activation.

METHODS

Thirty male patients underwent successful single-bundle (n = 15) and double-bundle (n = 15) ACL reconstructions; 15 healthy controls were included in the study. Anterior tibial translation was assessed at 30° of knee flexion in the resting position (0% quadriceps activation) and under 50% and 100% of maximum quadriceps concentric contraction using an isokinetic dynamometer with the KT-2000 arthrometer securely attached to the participants' knees.

RESULTS

The 2 ACL-reconstructed groups were similar regarding International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Score (KOOS), Tegner, and Lysholm scores and preliminary isokinetic evaluation (P = .38). Quadriceps activation significantly affected anterior tibial translation (P = .001, α = 0.98). In all 3 study groups, anterior tibial translation was significantly higher under 100% quadriceps activation compared with 0% contraction (P = .01) and 50% quadriceps activation (P = .047). There were no between-group differences in anterior tibial translation with 0%, 50%, or 100% quadriceps activation (P = .46).

CONCLUSIONS

Under quadriceps muscle activation, anteroposterior knee laxity in ACL-intact and ACL-reconstructed knees is gradually increased. Single-bundle and double-bundle ACL-reconstructed knees show a similar increase in anterior tibial translation under gradual quadriceps contraction. When comparing different ACL reconstruction techniques in the experimental setting, dynamic, in addition to static, testing is advised to reach a comprehensive assessment of anteroposterior knee stability.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

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.

No difference in revision rates between single- and double-bundle anterior cruciate ligament reconstruction: a comparative study of 16,791 patients from the Swedish national knee ligament register

PURPOSE

The purpose was to compare revision rates and patient-reported outcomes between single- and double-bundle anterior cruciate ligament (ACL) reconstructions.

METHODS

All patients from the Swedish National Knee Ligament Register from 2005 through 2011 who underwent primary ACL reconstruction with hamstring autografts were included. Patients with concomitant injuries, except meniscal and chondral injuries, were excluded. By December 31, 2011, 16,791 primary isolated ACL reconstructions had been registered, of which 16,281 were single-bundle and 510 were double-bundle. Cumulative revision rates were estimated using Kaplan-Meier analysis. The Knee injury and Osteoarthritis Outcome Score (KOOS) and EQ-5D were calculated at 1- and 2-year follow-ups.

RESULTS

The revision rate showed no statistically significant differences between the groups (P = .30). Over the 7-year observation period, 347 single-bundle (2.1%) and 8 double-bundle (1.6%) ACL reconstructions were revised. No significant differences in the KOOS or EQ-5D were found between the groups postoperatively. In addition, there were no differences in postoperative improvements in the KOOS or EQ-5D at 1- and 2-year follow-ups.

CONCLUSIONS

Revision rates after single- and double-bundle ACL reconstructions were low. No differences were found in revision rates, KOOS, and EQ-5D between the 2 techniques.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Anterior cruciate ligament reconstruction with contralateral autogenous patellar tendon graft: evaluation of donor site strength and subjective results

BACKGROUND

Few surgeons use a contralateral patellar tendon autograft for primary anterior cruciate ligament (ACL) reconstruction because of concern for donor site morbidity.

HYPOTHESIS

There will be no difference in quadriceps muscle strength or International Knee Documentation Committee (IKDC) subjective scores in patients with contralateral grafts compared with patients with ipsilateral grafts.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between 2007 and 2009, a total of 279 patients who underwent primary ACL reconstruction with autogenous patellar tendon graft from the contralateral knee met the inclusion criteria of unilateral knee involvement, no arthritic changes preoperatively, and minimum 2-year follow-up objective and subjective evaluations. A control group was obtained of 58 patients who had the same inclusion criteria and were of the same age but who underwent surgery with ipsilateral graft. Patients underwent a goal-directed and sequential postoperative rehabilitation program that first emphasized controlling a hemarthrosis and obtaining full knee range of motion immediately after surgery, followed by increasing leg strength and performing functional activities. The rehabilitation for the contralateral donor site emphasized high-repetition/low-resistance exercises beginning the day after surgery. The IKDC subjective data were compared between surgery groups. Quadriceps muscle strength was evaluated in both knees compared with the preoperative values obtained in the noninvolved knee and between knees at 2 years postoperatively.

RESULTS

Quadriceps muscle strength compared with the preoperative normal value (mean ± SD) was 105% ± 29% in the ipsilateral ACL-reconstructed knee versus 114% ± 28.4% in the contralateral donor knee (P < .01) and 116% ± 25% in the contralateral ACL-reconstructed knee (P = .0339). Mean side-to-side strength (ACL-reconstructed knee/opposite knee) was 98.4% ± 13.6% in the contralateral group versus 92.9% ± 13.0% in the ipsilateral group (P < .01). The mean total IKDC score was 92.4 ± 9.6 for the contralateral donor knee. The mean IKDC total score for the ACL-reconstructed knee was 88.8 ± 12.3 in the contralateral group and 88.9 ± 11.2 in the ipsilateral group (P = .626).

CONCLUSION

After ACL reconstruction with contralateral patellar tendon graft, patients can achieve strength symmetry between legs after surgery without experiencing adverse subjective symptoms after graft harvest. Furthermore, strength return can be superior with a contralateral graft than with an ipsilateral graft.

Is double-bundle anterior cruciate ligament reconstruction superior to single-bundle? A comprehensive systematic review

PURPOSE

To describe current evidence on single- and double-bundle anterior cruciate ligament (ACL) reconstruction, in terms of differences in knee kinematics, functional outcomes, patient-reported outcomes and graft failures.

METHODS

An electronic search was made using PubMed (MEDLINE), EMBASE and Cochrane Library. Studies published from January 1995 to August 2011 were included, and an updated search was made in PubMed in July 2012. Therapeutic studies, level of evidence I-III, for isolated primary ACL tears written in English comparing single- and double-bundle reconstruction reporting clinical outcome were included. Quality appraisal based on Cochrane Collaboration's tool for assessing risk of bias was performed.

RESULTS

Of 7,154 potentially eligible studies, 60 papers were included (25 randomised controlled trials, 21 prospective comparative studies, 14 retrospective comparative studies), comprising 4,146 patients (2,072 single-bundle, 2,074 double-bundle). Minor differences were found between study types. An analysis of graft failures revealed fewer re-ruptures in double-bundle reconstruction than single-bundle, 19 and 44, respectively. Up to 45 % of the studies reported a superior outcome in double-bundle reconstruction in terms of antero-posterior laxity, measured with the Lachman, anterior drawer, KT-1000/2000 and navigation. Measurements of rotatory laxity revealed superior results in double-bundle reconstruction measured with pivot shift and navigation in 18/42 (8/15 anatomically reconstructed) and 9/20 studies, respectively. Patient-reported outcome measures and functional outcomes did not differ to a large extent; however, differences when identified were almost exclusively in favour of double-bundle reconstruction.

CONCLUSION

Based on current evidence, double-bundle reconstruction appears to have fewer re-ruptures and less antero-posterior and rotatory laxity. Furthermore, no differences were found in short-term patient-reported outcome measures or objective findings. However, detailed statistical analyses of the included studies divided into homogeneous groups are needed to avoid reporting bias and to confirm any statistical difference.

A two- and five-year follow-up of clinical outcome after ACL reconstruction using BPTB or hamstring tendon grafts: a prospective intervention outcome study

PURPOSE

The aim of the present study was to evaluate and compare objective and subjective outcome in patients 2 and 5 years after anterior cruciate ligament (ACL) reconstruction with either bone-patellar tendon-bone (BPTB) or hamstring grafts. The second aim was to report the prevalence of re- and contralateral ACL ruptures.

METHODS

Sixty-eight patients (BPTB, n = 34 and hamstring graft, n = 34) were evaluated preoperatively, 2 and 5 years after ACL reconstruction. Anterior knee laxity and rotational knee joint stability, muscle torque, hop length, anterior knee pain, activity level and self-reported knee function and quality of life were evaluated within and between groups. The prevalence of re- and contralateral ACL ruptures was also recorded.

RESULTS

No significant difference in anterior knee laxity, rotational knee joint stability, hop length anterior knee pain or knee function and quality of life were noted at the 5-year follow-up. No significant differences in concentric or eccentric quadriceps torque at 90°/s and 230°/s were found at any of the follow-ups between and within grafts. A significant group difference in hamstring torque 1.05 (0.02) for BPTB and 0.89 (0.02) for hamstring grafts, and in hop length (leg symmetry index) follow-up 0.94 (0.07) for BPTB compared to 0.99 (0.07) for hamstring grafts (P = 0.002) was found at the 2 year follow-up in favour of the BPTB graft, but not at the 5 year follow-up. A significant improvement over time, irrespective of graft, was found in the KOOS's subscales Sport/Rec and quality of life (P < 0.001). None of the patients, irrespective of group, returned to their pre-injury level of sport (P < 0.05). Over the five postoperative years, one man and eight women (13 %) (hamstring graft, n = 5 and BPTB graft, n = 4), sustained a total of 11 (16.2 %) new ACL ruptures: seven (10.2 %) re-ruptures and four (5.9 %) ruptures of the contralateral ACL.

CONCLUSIONS

At the 5-year follow-up, there were no significant differences in terms of anterior knee laxity, rotational knee joint stability, muscle torque, anterior knee pain, hop performance, quality of life or activity level between patients who had undergone reconstruction with BPTB or hamstring grafts. None of the patients, irrespective of group, had returned to their pre-injury level of activity. Eight out of the nine patients who had sustained a second ACL rupture were women.

Arthroscopic anatomical double bundle anterior cruciate ligament reconstruction: A prospective longitudinal study

BACKGROUND

Single bundle anterior cruciate ligament (ACL) reconstruction has been the current standard of treatment for ACL deficiency. However, a significant subset of patients continue to report residual symptoms of instability with a poor pivot control. Cadaveric biomechanical studies have shown double bundle (DB) ACL reconstructions to restore the knee kinematics better. This study evaluates the outcome of DB ACL reconstruction.

MATERIALS AND METHODS

30 consecutive patients who underwent anatomic DB ACL reconstruction were included in this prospective longitudinal study. There were all males with a mean age of 25 ± 7.45 years. All patients were prospectively evaluated using GeNouRoB (GNRB) arthrometer, functional knee scores (International Knee Documentation Committee [IKDC] and Lysholm) and postoperative magnetic resonance imaging (MRI) for comparing the graft orientation and footprint of the reconstructed ACL with that of the normal knee.

RESULTS

The average followup was 36.2 months. At the time of final followup the mean Lysholm score was 93.13 ± 3.31. As per the objective IKDC score, 26 patients (86.6%) were in Group A while 4 patients (13.3%) were in Group B. The mean differential anterior tibial translation by GNRB, arthrometer was 1.07 ± 0.8 mm (range 0.1-2.3 mm). All cases had a negative pivot shift test. MRI scans of operated and the contralateral normal knee showed the mean sagittal ACL tibial angle coronal ACL tibial angle and tibial ACL footprint to be in accordance with the values of the contralateral, normal knee.

CONCLUSION

The study demonstrates that DB ACL reconstruction restores the ACL anatomically in terms of size and angle of orientation. However, long term studies are needed to further substantiate its role in decreasing the incidence of early osteoarthritic changes compared to the conventional single bundle reconstructions.

Tunnel communication and increased graft signal intensity on magnetic resonance imaging of double-bundle anterior cruciate ligament reconstruction

PURPOSE

This study aimed to evaluate the association between magnetic resonance imaging (MRI) findings of tunnel communication and increased graft signal intensity (SI) and clinical evaluation of knee stability and outcome after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Fifty-nine patients were evaluated with 1.5 T MRI and with clinical evaluation 2 years after DB ACL reconstruction. The MRI finding of tunnel communication was defined as the absence of a bony bridge between the anteromedial (AM) and posterolateral (PL) tunnels. The SI of the intra-articular portion of both grafts was analyzed on proton-density (PD)-weighted and T2-weighted images and graded on a scale, with I being a normal SI similar to that of the posterior cruciate ligament, II being > 50% of the graft having a normal SI, and III being < 50% of the graft having a normal SI. The clinical evaluation of knee stability and function included KT-1,000 arthrometric side-to-side difference, pivot shift test, and International Knee Documentation Committee (IKDC) and Lysholm knee evaluation scores. The association between the MRI findings and the clinical findings was calculated using the Fisher exact test and the 2-tailed t test.

RESULTS

Tunnel communication was seen in the femur in 10% of patients and in the tibia in 27% of patients. Increased graft SI was seen in 15% of the AM grafts and 59% of the PL grafts. No statistically significant association (P < .05) between the MRI findings of tunnel communication or increased graft SI and knee laxity was found.

CONCLUSIONS

The MRI findings of tunnel communication or increased graft SI were not associated with knee laxity 2 years after DB ACL reconstruction. Tibial tunnel communication was associated with increased range of movement with flexion, and increased AM graft SI was associated with reduced range of flexion in the knee.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Intermittently administered parathyroid hormone [1-34] promotes tendon-bone healing in a rat model

The objective of this study was to investigate whether intermittent administration of parathyroid hormone [1–34] (PTH[1–34]) promotes tendon-bone healing after anterior cruciate ligament (ACL) reconstruction in vivo. A rat model of ACL reconstruction with autograft was established at the left hind leg. Every day, injections of 60 μg PTH[1–34]/kg subcutaneously were given to the PTH group rats (n = 10) for four weeks, and the controls (n = 10) received saline. The tendon-bone healing process was evaluated by micro-CT, biomechanical test, histological and immunohistochemical analyses. The effects of PTH[1–34] on serum chemistry, bone microarchitecture and expression of the PTH receptor (PTH1R) and osteocalcin were determined. Administration of PTH[1–34] significantly increased serum levels of calcium, alkaline phosphatase (AP), osteocalcin and tartrate-resistant acid phosphatase (TRAP). The expression of PTH1R on both osteocytes and chondrocyte-like cells at the tendon-bone interface was increased in the PTH group. PTH[1–34] also enhanced the thickness and microarchitecture of trabecular bone according to the micro-CT analysis. The results imply that systematically intermittent administration of PTH[1–34] promotes tendon-bone healing at an early stage via up-regulated PTH1R. This method may enable a new strategy for the promotion of tendon-bone healing after ACL reconstruction.

Three-dimensional analysis of bone tunnel changes after anatomic double-bundle anterior cruciate ligament reconstruction using multidetector-row computed tomography

BACKGROUND

The femoral and tibial bone tunnel enlargement after anatomic double-bundle anterior cruciate ligament reconstruction (ACL-R) has not been fully documented.

PURPOSE

To evaluate the region-specific bone tunnel volume changes and those transpositions using 3-dimensional multidetector-row computed tomography (MDCT) after anatomic double-bundle ACL-R.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Eleven patients who underwent unilateral double-bundle ACL-R with hamstring tendon autografts were included in this study. MDCT scanning of their knees was performed at 3 weeks and 1 year after surgery. The bone tunnel regions were extracted from the MDCT images, and the longitudinal axis of each bone tunnel was divided into 3 equal sections. The centroids of the outside and the articular thirds were then extracted from the bone tunnel position. Changes in the bone tunnel volume and the transposition of the articular third were calculated and compared.

RESULTS

At 1 year postoperatively, as compared with the 3-week postoperative value (set at 100%), the femoral bone tunnel volume of the anteromedial bundle (AMB) and posterolateral bundle (PLB) changed to 77.4% ± 15.3% and 102.3% ± 19.2% in the outside third and 122.3% ± 31.8% and 112.5% ± 34.4% in the articular third, respectively. The tibial bone tunnel volume of the AMB and the PLB changed to 108.6% ± 28.7% and 105.4% ± 22.6% in the tibial articular third and 54.9% ± 25.8% and 52.5% ± 26.9% in the outside third, respectively. The femoral outside third of the AMB and the tibial outside third of both the AMB and PLB were significantly reduced in bone tunnel volume. The centroid of the femoral articular third of the AMB moved 13°, 1.1 ± 0.6 mm posterodistally, and that of the PLB moved 35°, 0.8 ± 0.4 mm anterodistally. Furthermore, the centroid of the tibial articular third of the AMB moved 14°, 2.0 ± 1.6 mm posterolaterally, and that of the PLB moved 72°, 1.0 ± 1.3 mm posterolaterally.

CONCLUSION

Compared with 3 weeks postoperatively, the articular side outlets of the femoral and tibial bone tunnels at 1 year postoperatively had enlarged slightly but statistically maintained their volume, and they had moved a little in the direction that the grafts were pulled.

Femoral fixation of hamstring tendon grafts in ACL reconstructions: the 2-year follow-up results of a prospective randomized controlled study

PURPOSE

Hamstring tendon grafts are commonly used in anterior cruciate ligament (ACL) reconstructions. A number of fixation devices are available; however, several have limited clinical support. To our knowledge, no randomized controlled study comparing the EZLoc and the Bone Mulch Screw for femoral fixation in ACL reconstruction exists. Therefore, the purpose of this study was to compare the results following the use of these two femoral fixation devices. Time in surgery for the two methods was also to be compared.

METHODS

A total of 110 patients between 18 and 45 years old at two orthopaedic departments, A (n = 55) and B (n = 55), were randomized to ACL reconstruction with femoral fixation of the hamstring graft with either the EZLoc or the Bone Mulch Screw. Surgical time was measured for each group. The patients were evaluated after 6 weeks and 3, 6, 12 and 24 months. The clinical examination included range of motion, evaluation of intraarticular swelling, tenderness at the lateral femoral condyle, the Lachman test, the Pivot shift test and the KT-1000 arthrometer. In addition, the visual analogue scale score for pain, the Tegner activity score, the Lysholm functional score and the knee injury and osteoarthritis outcome score were recorded. Knee extension and flexion muscle strength were also measured with a Biodex.

RESULTS

There were no significant differences in any of the parameters mentioned above at the 2-year follow-up evaluation. Three patients in each group underwent revision ACL reconstruction during the study. More than 95% of the knees in both groups were found to be stable. Good to excellent results were found for all selected knee scores in both groups. There were no statistically significant differences between the two groups in any of the muscle strength parameters. Time in surgery was statistically significantly shorter in the EZLoc group compared with the Bone Mulch group.

CONCLUSION

There were no statistically significant differences in clinical findings, knee scores or in muscle strength between the EZLoc group and the Bone Mulch group at the 2-year follow-up evaluation. Time in surgery was statistically significantly shorter for patients undergoing ACL reconstruction with hamstring grafts when the EZLoc femoral fixation device was used.

LEVEL OF EVIDENCE

II.

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.

Single-bundle or double-bundle for anterior cruciate ligament reconstruction: a meta-analysis

PURPOSE

To compare the clinical outcomes of anterior cruciate ligament (ACL) reconstruction with double-bundle and single-bundle techniques.

STUDY DESIGN

Meta-analysis

METHODS

We searched electronic databases including PubMed, Embase, Cochrane Central Register of Controlled Trials, and Google Scholar from 1966 to Jan 2012 to identify randomized controlled trials (RCTs) comparing clinical outcomes of anterior cruciate ligament (ACL) reconstruction with double-bundle and single-bundle techniques. Two reviewers independently extracted data and assessed trial quality. Meta-analysis was performed to pool results.

RESULTS

Nineteen RCTs were included with a total of 1686 patients. The pooled analysis across all studies showed that the double-bundle ACL reconstruction technique could have significantly better outcomes in rotational laxity, as assessed by the pivot-shift test, KT grading and IKDC grading than the single-bundle techniques. We found no evidence of a difference in function measured by IKDC scores, KT arthrometer, Lysholm knee, or Tegner activity scores and complications after operations between single and double-bundle ACL reconstruction groups.

CONCLUSION

Our meta-analysis demonstrated the superiority of double-bundle over single-bundle anterior cruciate ligament reconstruction. The double-bundle ACL reconstruction technique has better outcomes in rotational laxity (pivot-shift test, KT grading and IKDC grading). However, for functional recovery, there was no significant difference between single-bundle and double-bundle reconstruction techniques.

Isokinetic Quadriceps and Hamstring Muscle Strength after Anterior Cruciate Ligament Reconstruction: Comparison between Single-bundle and Double-bundle Reconstruction

Introduction

Clinical studies have not yet proven whether single-bundle (SB) or double-bundle (DB) anterior cruciate ligament (ACL) reconstruction is superior. Nonetheless, quadriceps and hamstring muscle deficit is common after ACL reconstruction and it may affect the final outcome. The purpose of this study was to compare the isokinetic quadriceps and hamstring muscle strength after SB-ACL and DB-ACL reconstruction.

Materials and methods

We recruited 40 patients with ACL reconstruction (20 SB and 20 DB) by the same team of surgeons from 2006 to 2009. Demographic data of both groups were comparable. Lower extremity concentric isokinetic peak extension and flexion torques were assessed at angular velocities of 60°/second, 180°/second, and 300°/second preoperatively and at least 1 year postoperatively. Clinical evaluation was performed, including anterior stability with an arthrometer (model KT-1000), Lysholm score, Tegner activity score, single leg hop test, and International Knee Documentation Committee score. Data were analysed statistically.

Results

The isokinetic quadriceps and hamstring peak torque values in both the SB and DB groups did not show any significant difference. The maximum displacement upon KT-1000 arthrometer measurement appeared lower in the DB group but the difference was not significant. The side-to-side percentage deficits in quadriceps and hamstring peak torque at postoperative assessment were comparable in both groups.

Conclusion

Isokinetic quadriceps and hamstring muscle strength after SB-ACL or DB-ACL reconstruction was comparable.

Second-look arthroscopic evaluation of chondral lesions after isolated anterior cruciate ligament reconstruction: single- versus double-bundle reconstruction

BACKGROUND

Double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) has been reported to yield better joint stability than single-bundle (SB) reconstruction. Few studies have compared the 2 techniques with regard to postoperative articular cartilage changes.

HYPOTHESIS

Less cartilage damage should occur in the short term after DB ACLR than after SB ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

The study included 52 patients (27 in the DB group and 25 in the SB group) with no chondral or meniscus injury at primary ACLR, as confirmed under arthroscopy. Four-strand and 6- to 8-strand hamstring autografts, respectively, were used for transtibial SB and 4-tunnel DB reconstruction. Each graft was fixed with an EndoButton bioabsorbable interference screw and a staple. Cartilage status at 6 identified regions was evaluated by second-look arthroscopy and the Outerbridge classification. Other assessments at final follow-up included International Knee Documentation Committee (IKDC) score, Tegner and Lysholm scores, side-to-side difference on KT-2000 arthrometer, and range of motion.

RESULTS

The mean time from reconstruction to second-look arthroscopy was 18.2 and 17.3 months for the DB and SB groups, respectively. Both groups had cartilage lesions at the patellofemoral joint (patella, 9 vs 13; trochlea, 5 vs 12) and the medial compartment (1 vs 2). Significantly less severe lesions were found in the DB group than in the SB group (mean grade, 0.33 vs 0.96; P < .05). No significant differences were found between the 2 groups in terms of cartilage status at other regions, IKDC score, Lysholm score, Tegner score, KT-2000 arthrometer anterior laxity, or range of motion.

CONCLUSION

Chondral lesions were found postoperatively in both DB and SB ACLR groups with hamstring autograft. The DB ALCR led to less cartilage damage at the femoral trochlea at short-term follow-up.

From open to arthroscopic anatomical ACL-reconstructions: the long way round. A statement paper

The single-incision anterior cruciate ligament (ACL) reconstruction evidently has its shortcomings. In an attempt to improve the biomechanical but also the biological state of the knees after an ACL-reconstruction, double, even triple-bundle reconstructions have been popularised recently. As a positive side effect, details concerning ACL-insertion anatomy were brought back into the focus. In our opinion it would be more straight forward and logical to replace the non-anatomical single-incision technique with a more anatomic single-bundle ACL-reconstruction technique.

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

PURPOSE

To compare the short- and long-term clinical outcomes of the double-bundle (DB) anterior cruciate ligament (ACL) reconstruction with those of single-bundle (SB) ACL reconstruction.

METHODS

An electronic search of the database PubMed (1966-September 2011), EMBASE (1984-September 2011), and Cochrane Controlled Trials Register (CENTRAL; 3rd Quarter, 2011) was undertaken to identify relevant studies. Main clinical outcomes were knee stability measurements including KT-1000 arthrometer measurement, Pivot shift test, and Lachman test, and clinical outcome measurements including International Knee Documentation Committee (IKDC), Lysholm knee score, Tegner activity score, and complications.

RESULTS

Eighteen studies were finally included in this meta-analysis, which were all classified as high risk of bias according to the Collaboration's recommended tool. It is seen that compared to SB ACL reconstruction, DB ACL reconstruction results in a KT-1000 arthrometer outcome 0.63 and 1.00 mm closer to the normal knee in a short- and long-term follow-up, respectively. Our results also reveal that DB-treated patients have a significantly higher negative rate of the pivot shift test (p < 0.00001 and = 0.006 in a short- and long-term follow-up, respectively) and Lachman test (n.s. and p < 0.0001 in a short- and long-term follow-up, respectively) compared to SB-treated patients. As for the clinical outcome measurements, a significant difference is found between SB versus DB ACL reconstruction regarding the IKDC (p = 0.006 and < 0.0001 in a short- and long-term follow-up, respectively) and complications (p = 0.03), while there is no significant difference between the two groups regarding Lysholm knee score (n.s.) and Tegner activity score (n.s.).

CONCLUSION

Overall, double-bundle ACL reconstruction yields better clinical outcomes when compared to single-bundle ACL reconstruction.

LEVELS OF EVIDENCE

II.

Specific compartmental analysis of cartilage status in double-bundle ACL reconstruction patients: a comparative study using pre- and postoperative MR images

PURPOSE

The purpose of this study was to evaluate the changes in the site-specific cartilage status after a double-bundle ACL reconstruction using preoperative and follow-up MR images.

METHODS

Thirty-six knees that underwent a double-bundle ACL reconstruction from 2001 to 2009 with the available preoperative and follow-up magnetic resonance imaging were included. Patients with a meniscal injury were compared with those without a meniscal injury. The cartilage morphology was classified using a 6-grade scale [from 0 = normal thickness and signal, to 6 = diffuse full-thickness loss (>75 % of the region)]. The changes in cartilage status were evaluated at 14 sites.

RESULTS

Cartilage changes were observed in all sites and were classified according to the site and degree of change. The majority of changes were grade 0 and 1, which accounted for 68 and 16.8 % of changes, respectively. The patella medial facet and anterolateral and centromedial femoral regions showed significantly more cartilage loss than the posteromedial, centrolateral, anterolateral, and anteromedial tibial regions. No significance was observed between the knees with or without combined injuries (n.s.). On the other hand, knees with or without combined injuries showed a different pattern of cartilage change, as demonstrated by different levels of grade change at sites.

CONCLUSIONS

The change in cartilage status was minimal after a double-bundle ACL reconstruction. The patella medial facet, lateral femur anterior region, and medial femur central region showed significantly more cartilage loss than the medial tibia posterior, lateral tibia central, lateral tibia anterior, and medial tibia anterior regions. The presence of a combined injury did not affect the cartilage status changes, even though it was underpowered and too short term to assess the influence of the meniscal injury.

LEVEL OF EVIDENCE

Case series, Level IV.

Three-dimensional reconstruction computed tomography evaluation of tunnel location during single-bundle anterior cruciate ligament reconstruction: a comparison of transtibial and 2-incision tibial tunnel-independent techniques

Background

Anatomic tunnel positioning is important in anterior cruciate ligament (ACL) reconstructive surgery. Recent studies have suggested the limitations of a traditional transtibial technique to place the ACL graft within the anatomic tunnel position of the ACL on the femur. The purpose of this study is to determine if the 2-incision tibial tunnel-independent technique can place femoral tunnel to native ACL center when compared with the transtibial technique, as the placement with the tibial tunnel-independent technique is unconstrained by tibial tunnel.

Methods

In sixty-nine patients, single-bundle ACL reconstruction with preservation of remnant bundle using hamstring tendon autograft was performed. Femoral tunnel locations were measured with quadrant methods on the medial to lateral view of the lateral femoral condyle. Tibial tunnel locations were measured in the anatomical coordinates axis on the top view of the proximal tibia. These measurements were compared with reference data on anatomical tunnel position.

Results

With the quadrant method, the femoral tunnel centers of the transtibial technique and tibial tunnel-independent technique were located. The mean (± standard deviation) was 36.49% ± 7.65% and 24.71% ± 4.90%, respectively, from the over-the-top, along the notch roof (parallel to the Blumensaat line); and at 7.71% ± 7.25% and 27.08% ± 7.05%, from the notch roof (perpendicular to the Blumensaat line). The tibial tunnel centers of the transtibial technique and tibial tunnel-independent technique were located at 39.83% ± 8.20% and 36.32% ± 8.10%, respectively, of the anterior to posterior tibial plateau depth; and at 49.13% ± 4.02% and 47.75% ± 4.04%, of the medial to lateral tibial plateau width. There was no statistical difference between the two techniques in tibial tunnel position. The tibial tunnel-independent technique used in this study placed femoral tunnel closer to the anatomical ACL anteromedial bundle center. In contrast, the transtibial technique placed the femoral tunnel more shallow and higher from the anatomical position, resulting in more vertical grafts.

Conclusions

After single-bundle ACL reconstruction, three-dimensional computed tomography showed that the tibial tunnel-independent technique allows for the placement of the graft closer to the anatomical femoral tunnel position when compared with the traditional transtibial technique.

Outcomes of anterior cruciate ligament reconstruction using single-bundle versus double-bundle technique: meta-analysis of 19 randomized controlled trials

PURPOSE

The purpose of this study was to test the hypothesis that double-bundle anterior cruciate ligament reconstruction yields better improvement in stability and functional recovery than the single-bundle technique.

METHODS

An Internet search was performed of the Pubmed, Embase, AMED, Cochrane Library, CNKI, Wanfang and VIP databases to find all published randomized controlled trials of anterior cruciate ligament reconstruction treated with the double-bundle versus single-bundle technique. Outcomes of stability improvement and functional recovery were meta-analyzed.

RESULTS

One thousand six hundred sixty-seven patients in 19 randomized controlled trials were involved in the meta-analysis. The overall relative risk (with 95% confidence interval) calculated with the random effects model in the pivot shift test and the International Knee Documentation Committee (IKDC) objective score for single-bundle versus double-bundle ACL reconstruction were 0.77 (0.67, 0.89) and 0.80 (0.68, 0.93), respectively. The overall relative risk calculated with the fixed effects model in the Lachman test was 0.84 (0.78 to 0.92). The overall standard mean differences (with 95% confidence interval) calculated with the random effects model were 0.26 (0.05, 0.46) for anterior side-to-side difference; -0.08 (-0.28,0.12) for Lysholm score; Tegner activity scale, -0.41 (-0.85, 0.03) for Tegner activity score; and -0.08 (-0.32, 0.15) for IKDC subjective score.

CONCLUSIONS

Meta-analysis of random controlled trials revealed that double-bundle anterior cruciate ligament reconstruction resulted in significantly better anterior and rotational stability and higher IKDC objective scores compared with single-bundle reconstruction. However, the meta-analysis did not detect any significant differences in subjective outcome measures between double-bundle and single-bundle reconstruction, as evidenced by the Lysholm score, Tegner activity scale, and IKDC subjective score.

LEVEL OF EVIDENCE

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