Single- versus double-bundle ACL reconstruction: is there any difference in stability and function at 3-year followup?

The increased lateral tibial slope may result in inferior long-term clinical outcome after DB-ACL reconstruction

PURPOSE

To determine if there is a correlation between lateral tibial slope and long-term clinical results in patients who underwent double-bundle ACL reconstruction.

METHODS

We retrospectively reviewed patients that received double-bundle ACL reconstruction at a single institution by a single surgeon from January 2011 to December 2014. All the magnetic resonance imaging were reviewed and lateral tibial slopes (LTS) were recorded by an experienced surgeon and rechecked by the other two authors of this study that specialized in orthopedic knee surgery. The relationship between PROMs measurement and lateral tibial slope were analyzed. The patients were then separated into two groups (LTS > 7.4° and < 7.4°) according to the previous study.

RESULTS

A total of 119 patients were enrolled in this study. All enrolled patients were followed for at least 8 years. The PROMS result were negatively correlated with the lateral tibial slope (p values all < 0.001). The patients with high lateral tibial slope had significantly lower PROMS values (Lysholm 94.26 ± 5.61 vs 80.15 ± 8.28, p = 0.013; IKDC 82.99 ± 4.55 vs 70.09 ± 7.15, p = 0.003; Tegner 9.32 ± 0.95 vs 6.85 ± 1.99, p < 0.001). Finally, the LTS cutoff value between patients with "Good" and "Fair" Lysholm score in our study was 7.55 degrees.

CONCLUSIONS

Patients with high lateral tibial slope may result in inferior long-term subjective outcomes. The using of double-bundle ACL reconstruction along cannot overcome the negative impact caused by steep lateral tibial slope. A lateral tibial slope of 7.55° may be used as a cut-off for a good clinical outcome.

LEVEL OF EVIDENCE

III retrospective comparative prognostic trial.

Single Bundle Anterior Cruciate Ligament With Anterolateral Ligament Reconstruction Yields Similar Clinical and Radiographic Results at Minimum 2-Year Follow-Up Versus Double Bundle Anterior Cruciate Ligament Reconstruction: A Prospective Randomized Controlled Trial

PURPOSE

To compare the clinical, radiographic, and second-look arthroscopic outcomes between double-bundle (DB) anterior cruciate ligament (ACL) reconstruction (DB group) and combined single-bundle (SB) ACL and anterolateral ligament (ALL) reconstruction (SB + ALL group) by a prospective randomized controlled trial.

METHODS

From May 2019 to June 2020, 84 patients were enrolled in this study. Among them, 10 were lost to follow-up. Thirty-six and 38 patients were successfully allocated to the DB (mean follow up 27.3 ± 4.2 months) and SB + ALL groups (27.2 ± 4.5 months), respectively. The preoperative and postoperative Lachman test, pivot shift test, anterior translation on stress radiographs, KT-2000 arthrometer, Lysholm score, International Knee Documentation Committee score, and Tegner activity score were evaluated and compared. Graft continuity was evaluated using postoperative magnetic resonance imaging (MRI) (32 and 36 patients underwent MRI in the DB and SB + ALL groups at 7.4 ± 3.2 and 7.5 ± 2.9 months after surgery, respectively), and second-look examinations (second-look examination and tibial screw removal were performed concomitantly when patients (1) had tibial screw-related irritation or (2) needed the screws removed, 28 and 23 patients underwent examinations in the DB and SB + ALL groups at 24.0 ± 6.8 and 24.9 ± 8.1 months after surgery, respectively). All measurements were compared between the groups.

RESULTS

Postoperative clinical outcomes significantly improved in both groups. (All variables showed P < .001) No statistically different outcomes were found between the 2 groups. Additionally, postoperative graft continuity on MRI and second-look examinations were not different between the 2 groups.

CONCLUSIONS

The DB and SB + ALL groups showed similar postoperative clinical, radiographic, and second-look arthroscopic outcomes. Both groups showed excellent postoperative stability and clinical outcomes compared with the preoperative measurements.

LEVEL OF EVIDENCE

Level II, randomized controlled trial.

Reconstruction of the anterior cruciate ligament: a historical view

Management of anterior cruciate ligament (ACL) tears has continuously evolved since its first description in approximately 170 A.D. by Claudius Galenus of Pergamum and Rome. The initial immobilization using casts was replaced by a variety of surgical and conservative approaches over the past centuries. The first successful case of ACL repair was conducted by Mayo Robson in 1885, suturing cruciate at the femoral site. In the nineteenth century, surgical techniques were focused on restoring knee kinematics and published the first ACL repair. The use of grafts for ACL reconstruction was introduced in 1917 but gained popularity in the late 1900s. The introduction of arthroscopy in the 1980s represented the greatest milestones in the development of ACL surgery, along with the refinements of indications, development of modern strategies, and improvement in rehabilitation methods. Despite the rapid development and multitude of new treatment approaches for ACL injuries in the last 20 years, autografting has remained the treatment of choice. Compared to the initial methods, arthroscopic procedures are mainly performed, and more resistant and safer fixation devices are available. This results in significantly less trauma from the surgery and more satisfactory long-term results. The most commonly used procedures are still patellar tendon or hamstring autograft. Additionally, popular, but less common, is the use of quadriceps tendon (QT) grafts and allografts. In parallel with surgical developments, biological reconstruction focusing on the preservation of ACL remnants through the use of cell culture techniques, partial reconstruction, tissue engineering, and gene therapy has gained popularity. In 2013, Claes reported the discovery of a new ligament [anterolateral ligament (ALL)] in the knee that could completely change the treatment of knee injuries. The intent of these modifications is to significantly improve the primary restriction of rotational laxity of the knee after ACL injury. Kinematic studies have demonstrated that anatomic ACL reconstruction and anterolateral reconstruction are synergistic in controlling pivot displacement. Recently, there has been an increased focus on the application of artificial intelligence and machine learning to improve predictive capability within numerous sectors of medicine, including orthopedic surgery.

Double-Versus Single-Bundle Anterior Cruciate Ligament Reconstructive Surgery: A Prospective Study With >1 Year Follow-Up

Background The increased prevalence of knee trauma predominantly adds to the anterior cruciate ligament (ACL) tear frequencies that require single- or double-bundle reconstructive surgeries. Few studies have demonstrated the superior results of double-bundle reconstruction compared to single-bundle approaches. This study investigated the knee function improvement capacity of both reconstruction techniques in patients with ACL tears. Methods Thirty cases with ACL tears have been enrolled and segregated equally in distinct (single-bundle versus double-bundle) batches. The diagnostic assessments were undertaken through comprehensive clinical history, knee radiographs, Lysholm scoring, the International Knee Documentation Committee (IKDC) scale, the Lachman analysis, the International Knee Documentation Committee (IKDC) scale, and the pivot shift method. Results After one year, there was a significant enhancement in the postoperative versus preoperative Lysholm scores in the single-bundle (58.5 ± 21.2 vs. 82.4 ± 26.2, p<0.001) and double-bundle (86.4 ± 22.8 vs 60.3 ± 19.2, p<0.001) groups. There was a significant improvement in the IKDC scores after a follow-up period of one year (p-value: 0.012 and p-value: 0.002, respectively) in both of the study batches. After a year of follow-up, Lysholm scores (p=0.352) and IKDC scores (p=0.574) between the study groups (82.4 ± 26.2 vs. 86.4 ± 22.8) were comparable. Conclusion The clinical outcomes remained comparable between subjects with single-bundle reconstruction versus double-bundle reconstruction subjects with ACL injuries. Findings were similar between the groups after one year and two years of surgical interventions.

Intra-Articular Biomechanical Changes of the Meniscus and Ligaments During Stance Phase of Gait Circle after Different Anterior Cruciate Ligament Reconstruction Surgical Procedures: A Finite Element Analysis

OBJECTIVE

The debate on the superiority of single- or double-bundle for anterior cruciate ligament reconstruction has not ceased. The comparative studies on intra-articular biomechanics after different surgical reconstructions are rare. This study is to evaluate the biomechanical stress distribution intra-knee after single- and double-bundle anterior cruciate ligament reconstruction by three-dimensional finite element analysis, and to observe the change of stress concentration under the condition of vertical gradient loads.

METHODS

In this study, magnetic resonance imaging data were extracted from patients and healthy controls for biomechanical analysis. Patients included in the three models were matched in age and sex. The strength and distribution of induced stresses were analyzed in two frequently used procedures, anatomical single-bundle anterior cruciate ligament reconstruction and anatomical double-bundle anterior cruciate ligament reconstruction, using femoral-graft-tibial system under different loads, to mimic a post-operation mechanical motion. The three-dimensional finite-element models for normal ligament and two surgical methods were applied. A vertical force simulating daily walking was performed on the models to assess the interfacial stresses and displacements of intra-articular tissues and ligaments. The evaluation results mainly included the stress of each part of ligament and meniscus. The stress values of different parts of three models were extracted and compared.

RESULTS

The stress of ligament/graft at femoral side of three finite-element models was significantly higher than at tibial side, while the highest level was observed in single-bundle reconstruction finite-element model. With the increase of force, the maximum stress in the medial (7.1-7.1 MPa) and lateral (4.9-7.4 MPa) meniscus of single-bundle reconstruction finite-element model shifted from the anterior horn to the central area (p = 0.0161, 0.0479, respectively). The stress was shown to be at a lower level at femoral side and posterior cruciate ligament of intra-knee in two reconstruction finite-element models than that in normal finite-element models, while presented higher level at the tibial side than normal knee (p = 0.3528). The displacement of the femoral side and intra-knee areas in reconstruction finite-element models was greater than that in normal finite-element model (p = 0.0855).

CONCLUSION

Compared with the single-bundle technique, the graft of double-bundle anterior cruciate ligament reconstruction has better stress dissipation effect and can prevent postoperative meniscus tear more effectively.

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.

Age-related changes in microRNAs expression in cruciate ligaments of wild-stock house mice

Cruciate ligaments (CL) of the knee joint are injured following trauma or aging. MicroRNAs (miRs) are potential therapeutic targets in musculoskeletal disorders, but there is little known about the role of miRs and their expression ligaments during aging. This study aimed to (1) identify if mice with normal physical activity, wild-stock house mice are an appropriate model to study age-related changes in the knee joint and (2) investigate the expression of miRs in aging murine cruciate ligaments. Knee joints were collected from 6 and 24 months old C57BL/6 and wild-stock house mice (Mus musculus domesticus) for ligament and cartilage (OARSI) histological analysis. Expression of miR targets in CLs was determined in 6-, 12-, 24-, and 30-month-old wild-stock house mice, followed by the analysis of predicted mRNA target genes and Ingenuity Pathway Analysis. Higher CL and knee OARSI histological scores were found in 24-month-old wild-stock house mice compared with 6- and 24-month-old C57BL/6 and 6-month-old wild-stock house mice (p < 0.05). miR-29a and miR-34a were upregulated in 30-month-old wild-stock house mice in comparison with 6-, 12-, and 24-month-old wild-stock house mice (p < 0.05). Ingenuity Pathway Analysis on miR-29a and 34a targets was associated with inflammation through interleukins, TGFβ and Notch genes, and p53 signaling. Collagen type I alpha 1 chain (COL1A1) correlated negatively with both miR-29a (r = -0.35) and miR-34a (r = -0.33). The findings of this study support wild-stock house mice as an appropriate aging model for the murine knee joint. This study also indicated that miR-29a and miR-34a may be potential regulators of COL1A1 gene expression in murine CLs.

In vivo knee rotational stability 2 years after the ACL reconstruction using a quadriceps tendon graft with bone block and bone-patellar tendon-bone graft

INTRODUCTION

The aim of this prospective randomised study was to evaluate clinical results and rotational stability at least 2 years after single-bundle anatomic anterior cruciate ligament reconstruction using a quadriceps tendon graft with bone block (BT) and bone-patellar tendon-bone graft (BTB).

MATERIALS AND METHODS

In both groups (BT and BTB), 40 patients selected prospectively at random were evaluated. The mean follow-up after the surgery was 28 months (range 24-33 months). A navigation system was used to measure rotational stability of the knee joint. Cincinnati, Lysholm, and IKDC scores and visual analog score (VAS) were used to evaluate clinical results and the non-parametric Wilcoxon test was used for the statistical analysis.

RESULTS

After the BT reconstruction, the mean internal rotation of the tibia (IR) was 9.5°. In the contralateral healthy knee joint, IR was 8.6° at average. After the BTB reconstruction, the mean IR was 9.9°. In the contralateral healthy knee joint, IR was 8.7° at average. We did not find any statistically significant difference in IR stability between BT and BTB reconstruction. In terms of clinical results, regarding the VAS, patients perceive significantly more pain after the BTB reconstruction (p < 0.05). Kneeling was reported more difficult and painful after BTB reconstruction.

CONCLUSIONS

The BT reconstruction of the ACL provides similar clinical results, less pain, better flexion and the same rotational stability of the knee in comparison with the BTB reconstruction.

Anterior Cruciate Ligament Reconstruction with Autologous Hamstring Single- versus Double-Bundle Graft: A Prospective Study with 10-Year Follow-up

The purpose of the present study was to compare the clinical and subjective outcomes of anterior cruciate ligament (ACL) reconstruction using an autologous hamstring double bundle (DB) with a single bundle (SB) after a 10-year follow-up. A prospective comparative cohort study was performed of 47 consecutive patients with ACL rupture included between May 2006 and March 2008. Inclusion criteria were less than 2 years since the injury date, no previous surgery on the affected knee, and having closed growth plates. Patients were divided into two groups: (1) SB group (n = 25) and (2) DB group (n = 22). Patients underwent evaluation before surgery and at 1 and 10 years postoperatively. The clinical evaluation included the International Knee Documentation Committee (IKDC) Questionnaire, pivot shift test, and single hop test, as well as X-rays (anterior drawer X-rays on a Telos stress radiography). Range of motion (ROM) was assessed at 10-year follow-up. Both groups were similar in terms of baseline characteristics. Post hoc power analysis showed that among 30 and 226 patients would be needed for statistical significance, depending on the outcome. With the numbers available, no significant differences were observed in subjective IKDC, anterior stability (measured with Telos), and functional test outcomes (single hop test) between both groups at 1 and 10 years postoperatively. Regarding rotational instability (pivot-shift test), DB group was significantly superior (p = 0.002). Regarding ROM, no significant differences were observed between groups. No failure was registered in any of the groups. ACL reconstruction (ACLR) with an autologous hamstring, both with bundles and DB, shows overall better outcomes compared with the status before surgery. DB ACLR provides better rotational control of the knee, an outcome that is maintained after 10 years.

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.

Systematic Review of Surgical Technique and Tunnel Target Points and Placement in Anatomical Single-Bundle ACL Reconstruction

The purpose of this systematic review was to reveal the trend in surgical technique and tunnel targets points and placement in anatomical single-bundle anterior cruciate ligament (ACL) reconstruction. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, data collection was performed. PubMed, EMBASE, and Cochran Review were searched using the terms "anterior cruciate ligament reconstruction," "anatomic or anatomical," and "single bundle." Studies were included when they reported clinical results, surgical technique, and/or tunnel placement evaluation. Laboratory studies, technical reports, case reports, and reviews were excluded from this study. From these full article reviews, graft selection, method of creating the femoral tunnel, and femoral and tibial tunnel target points and placement were evaluated. In the 79 studies included for data evaluation, the selected grafts were: bone patella tendon bone autograft (12%), and hamstring autograft (83%). The reported methods of creating the femoral tunnel were: transportal technique (54%), outside-in technique (15%), and transtibial technique (19%). In the 60 studies reporting tunnel target points, the target point was the center of the femoral footprint (60%), and the center of the anteromedial bundle footprint (22%). In the 23 studies evaluating tunnel placement, the femoral tunnel was placed in a shallow-deep direction (32.3%) and in a high-low direction (30.2%), and the tibial tunnel was placed from the anterior margin of the tibia (38.1%). The results of this systematic review revealed a trend in anatomical single-bundle ACL reconstruction favoring a hamstring tendon with a transportal technique, and a tunnel target point mainly at the center of the ACL footprint. The level of evidence stated is Systematic review of level-III studies.

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.

Does a combined screw and dowel construct improve tibial fixation during anterior cruciate ligament reconstruction?

PURPOSE

The aims of the present study were to compare the biomechanical properties of tibial fixation in hamstring-graft ACL reconstruction using interference screw and a novel combination interference screw and dowel construct.

MATERIAL AND METHODS

We compared the fixation of 30 (2- and 4-stranded gracilis and semitendinosis tendons) in 15 fresh-frozen porcine tibiae with a biocomposite resorbable interference screw (Group 1) and a screw and dowel construct (Group 2). Each graft was subjected to load-to-failure testing (50 mm/min) to determine maximum load, displacement at failure and pullout strength.

RESULTS

There were no significant differences between the biomechanical properties of the constructs. Multivariate analysis demonstrated that combination constructs (β = 140.20, p = 0.043), screw diameter (β = 185, p = 0.006) and 4-strand grafts (β = 51, p = 0.050) were associated with a significant increase in load at failure. Larger screw diameter was associated with increased construct stiffness (β = 20.15, p = 0.020).

CONCLUSION

The screw and dowel construct led to significantly increased fixation properties compared to interference screws alone in a porcine model. Increased screw diameter and utilization of 4-strand ACL grafts also led to improvement in load-to-failure of the construct. However, this is an in vitro study and additional investigations are needed to determine whether the results are reproducible in vivo.

LEVEL OF EVIDENCE

Level V; Biomechanical study.

Gracilis and semitendinosus moment arm decreased by fascial tissue release after hamstring harvesting surgery: a key parameter to understand the peak torque obtained to a shallow angle of the knee

PURPOSE

Semitendinosus and gracilis muscles whose tendons are used in surgical reconstruction of the anterior cruciate ligament maintain their contractile ability, but the peak torque angle of hamstring muscles shifted to a shallow angle postoperatively. The goal was to quantify the influence of the myofascial structures on instantaneous moment arms of knee muscles to attempt explaining the above-mentioned post-surgical observations.

METHODS

Hamstring harvesting procedures were performed by a senior orthopaedic surgeon on seven lower limbs from fresh-frozen specimens. Femoro-tibial kinematics and tendons excursion were simultaneously recorded at each step of the surgery.

RESULTS

No significant difference was demonstrated for instantaneous moment arm of gracilis during anterior cruciate ligament surgery (84% of the maximum intact values; P ≥ 0.05). The first significant semitendinosus moment arm decrease was observed after tendon harvesting (61% of the maximum intact values; p ≤ 0.005). After hamstring harvesting, the maximum and minimum moment arm (both gracilis and semi tendinosus) shifted to a shallow angle and 90°, respectively.

CONCLUSION

Moment arm modifications by paratenons and the loose connective tissue release are essential to understand the peak torque obtained to a shallow angle.

LEVEL OF EVIDENCE

Basic science study, biomechanics.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRANSLATIONAL POTENTIAL STATEMENT

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

Biological Augmentation of ACL Repair and Reconstruction: Current Status and Future Perspective

Historically, anterior cruciate ligament (ACL) suture repair mostly resulted in failure because of intra-articular hypovascularity and poor intrinsic healing capacity of ACL. ACL reconstruction was therefore deemed the gold standard with a high success rate because of more evolved surgical technique. There are, however, clinical and subclinical disadvantages of reconstruction; low rate in full recovery to sports, donor harvest morbidity, tunnel enlargement, and incomplete microscopic healing of the graft. Recent experimental and clinical studies on biological augmentation of mesenchymal stem cells, platelet-rich plasma, or the other biologic agents with scaffold suggested potential feasibility of positive effects by such bio-therapies for both ACL repair and reconstruction. Biological augmentation of ACL surgery is still in the exploratory stages and more evidence from preclinical and clinical studies is required for implementation in clinical practice.

Primary Anterior Cruciate Ligament Repair With Hyaluronic Scaffold and Autogenous Bone Marrow Aspirate Augmentation in Adolescents With Open Physes

It is well known that the anterior cruciate ligament (ACL) is the main stabilizer to the anterior tibial translation in the knee. The current gold standard of treatment for such lesions is ACL reconstruction. However, there are notable disadvantages to ACL reconstruction that include loss of proprioception, donor site morbidity, incomplete return to high-demand sports, and the inability to restore normal kinematics of the knee joint. Additionally, in adolescents who have open physes, there is a risk of potential iatrogenic growth plate injury. Tibial-sided soft-tissue avulsion is a rare subtype of ACL injuries. This Technical Note presents a method for primary anatomic ACL repair with a bioabsorbable scaffold and bone marrow concentrate augmentation for an acute distal ACL injury. Our technique is an alternative to reconstruction as it allows the preservation of the native insertion site and has the potential to reduce the risk of posttraumatic osteoarthritis.

Knee Osteoarthritis After Single-Bundle Versus Double-Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review of Randomized Controlled Trials

PURPOSE

To systematically review high-quality studies in the literature to compare the postoperative radiographic incidence of knee osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) with a single-bundle (SB) versus double-bundle (DB) graft.

METHODS

A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to locate randomized controlled trials that compared the postoperative progression of knee OA in SB versus DB ACLR patients. The search terms used were "anterior cruciate ligament reconstruction," "single-bundle," "double-bundle," "randomized," and "osteoarthritis." Patients were assessed based on radiographic evaluation (Kellgren-Lawrence [K-L] and objective International Knee Documentation Committee scales) and graft failure.

RESULTS

A total of 7 studies (5 Level I and 2 Level II) met the inclusion criteria, including 375 SB and 477 DB ACLR patients with a mean follow-up period of 5.3 years. Graft failure occurred in 3.2% of patients overall (27 of 852), with no significant difference between groups (P = .10). No significant difference in overall K-L grade distribution was found between groups (P = .90). Overall, 15.1% of patients (58 of 383) were given a K-L grade of 2 or greater, including 14.4% in the SB group (31 of 215) and 16.1% in the DB group (27 of 168) (P = .65). Using other, unconventional grading schemes, 2 studies found DB ACLR patients to have significantly fewer signs of radiographic knee OA at follow-up compared with SB ACLR patients (P < .05).

CONCLUSIONS

Patients undergoing ACLR with either an SB or DB graft can be expected to experience a similar incidence of postoperative knee OA at midterm follow-up according to the K-L grading system.

LEVEL OF EVIDENCE

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

Clinical and Functional Outcomes of Anterior Cruciate Ligament Reconstruction at a Minimum of 2 Years Using Adjustable Suspensory Fixation in Both the Femur and Tibia: A Prospective Study

Background:

The success of anterior cruciate ligament (ACL) reconstruction requires reliable and rigid graft fixation. Cortical suspensory fixation (CSF) devices have become an acceptable alternative to interference screws for soft tissue ACL grafts. However, CSF devices have been reported to be associated with tunnel widening and increased postoperative anterior laxity compared with interference screw fixation. Adjustable CSF devices were introduced to avoid these problems but have been associated with graft lengthening and inconsistent outcomes.

Purpose:

To (1) report the side-to-side difference (SSD) in anterior laxity at 150 N, clinical scores, and failure rates 2 years after ACL reconstruction with 4-strand semitendinosus autografts using an adjustable CSF device and (2) determine the preoperative factors associated with clinical outcomes.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 131 patients who had undergone primary ACL reconstruction, performed with 4-strand semitendinosus grafts that were secured using Pullup adjustable-length CSF devices with femoral and tibial fixation techniques, were prospectively enrolled in this study; 34 patients were excluded because of contralateral instability or ipsilateral knee injuries that required additional surgery. This left a cohort of 97 patients who were evaluated preoperatively and at 6, 12, and 24 months. The evaluation consisted of measuring the SSD in anterior laxity and patient-reported outcome scores (International Knee Documentation Committee [IKDC] and Lysholm scores). Regression analyses were performed to determine associations between these outcomes and 9 preoperative variables.

Results:

Only 2 patients could not be reached, 2 could not be evaluated because of contralateral ACL tears, and 2 had graft failure. At 2-year follow-up, the remaining 91 patients had a mean SSD in anterior laxity of 0.8 ± 1.8 mm (range, –4.2 to 5.3 mm), mean IKDC score of 87.6 ± 10.6 (range, 43.7-100.0), and mean Lysholm score of 90.8 ± 9.3 (range, 56.0-100.0). At final follow-up, compared with knees with partial ruptures, those with complete ruptures had equivalent laxity (P = .266) and Lysholm scores (P = .352) but lower IKDC scores (P = .009). Multivariable regression revealed that the IKDC score decreased with increased preoperative laxity (β = –1.35 [95% CI, –2.48 to –0.23]; P = .019).

Conclusion:

The novel adjustable-length CSF device produced satisfactory anterior laxity and clinical outcomes, with a failure rate of 2.1%, which compare favorably with those reported for nonadjustable CSF devices.

Passive anterior tibia translation in anterior cruciate ligament-injured, anterior cruciate ligament-reconstructed and healthy knees: a systematic review

Abstract

Anterior tibia translation (ATT) is mainly prevented by the anterior cruciate ligament. Passive ATT tests are commonly used to diagnose an anterior cruciate ligament (ACL) injury, to select patients for an ACL reconstruction (ACLR), and as an outcome measure after an ACLR. The aim of this review was to present an overview of possible factors determining ATT. A second purpose was to give a summary of the ATT measured in the literature in healthy, ACL-injured and ACLR knees and a comparison between those groups. A literature search was conducted with PubMed. Inclusion criteria were full-text primary studies published in English between January 2006 and October 2016. Studies included reported ATT in explicit data in healthy as well as ACL-injured or ACLR knees or in ACL-injured as well as ACLR knees. Sixty-one articles met inclusion criteria. Two articles measured the ATT in healthy as well as ACL-injured knees, 51 in ACL-injured as well as in ACLR knees, three in ACLR as well as in healthy knees and three in healthy, ACL-injured and ACLR knees. A difference in ATT is found between healthy, contralateral, ACLR and ACL-injured knees and between chronic and acute ACL injury. Graft choices and intra-articular injuries are factors which could affect the ATT. The mean ATT was lowest to highest in ACLR knees using a bone–patella tendon–bone autograft, ACLR knees using a hamstring autograft, contralateral healthy knees, healthy knees, ACLR knees with an allograft and ACL-injured knees. Factors which could affect the ATT are graft choice, ACL injury or reconstruction, intra-articular injuries and whether an ACL injury is chronic or acute. Comparison of ATT between studies should be taken with caution as a high number of different measurement methods are used. To be able to compare studies, more consistency in measuring devices used should be introduced to measuring ATT. The clinical relevance is that an autograft ACLR might give better results than an allograft ACLR as knee laxity is greater when using an allograft tendon.

Level of evidence

III.

No Difference in the KOOS Quality of Life Subscore Between Anatomic Double-Bundle and Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction of the Knee: A Prospective Randomized Controlled Trial With 2 Years' Follow-up

BACKGROUND

The double-bundle reconstruction technique was developed to resemble the properties of the native anterior cruciate ligament (ACL) more closely than the conventional single-bundle technique. The clinical benefit of the operative procedure is controversial, and there is a need for studies with a focus on patient-reported outcomes (PROs).

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

HYPOTHESIS

Anatomic double-bundle ACL reconstruction would be superior to anatomic single-bundle reconstruction regarding the change in the Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) subscore from baseline to 2-year follow-up.

METHODS

According to sample size calculations, 120 patients aged 18 to 40 years with a primary ACL injury of their knee were randomized to the anatomic double-bundle or anatomic single-bundle reconstruction groups. Patients with posterior cruciate ligament, posterolateral corner, or lateral collateral ligament injuries or with established osteoarthritis were excluded. Patients with residual laxity from a coexistent medial collateral ligament injury were excluded. Data were registered at baseline, 1 year, and 2 years. In 24 patients, postoperative 3-dimensional computed tomography was performed to verify the positioning of the bundles. The outcome measures were the change in KOOS subscores and the International Knee Documentation Committee 2000 subjective score, pivot-shift test result, Lachman test finding, KT-1000 arthrometer measurement, activity level, return-to-sports rate, and osteoarthritic changes on radiographs. A linear mixed model was used for the analysis of all the PROs, including the primary outcome.

RESULTS

The change in the KOOS QoL subscore from baseline to 2-year follow-up was not different between the double- and single-bundle groups (mean change, 29.2 points vs 28.7 points, respectively; -0.5-point difference; 95% CI, -8.4 to 7.4 points; P = .91). Neither were there any differences between the 2 groups in the remaining PROs, knee laxity measurements, or activity levels of the patients. Radiological signs of osteoarthritis were found in 2 patients. Eleven patients had a graft rupture: 8 in the single-bundle group and 3 in the double-bundle group ( P = .16). Three-dimensional computed tomography of the knees verified the positioning of the anteromedial bundle, posterolateral bundle, and single-bundle grafts to be within acceptable limits.

CONCLUSION

There was no difference in the KOOS QoL subscore, the remaining PROs, knee laxity measurements, or activity levels comparing the double- and single-bundle ACL reconstruction techniques. The number of bundles does not seem to influence clinical and subjective outcomes, as long as the tunnels are adequately positioned. Registration: NCT01033188 ( ClinicalTrials.gov identifier).

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

PURPOSE

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

METHODS

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

RESULTS

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

LEVEL OF EVIDENCE

III.

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.

In vivo knee rotational stability 2 years after double-bundle and anatomic single-bundle ACL reconstruction

PURPOSE

The objective of this study was to evaluate knee rotational stability at least 2 years after anatomic single-bundle anterior cruciate ligament (ACL) reconstruction (SB) and double-bundle ACL reconstruction (DB) in comparison with the contralateral healthy knee joint. The Cincinnati, Lysholm and IKDC scores were analysed too.

METHODS

There were 40 patients in both groups, the mean follow-up was 27 months. For all measurements, the navigation system OrthoPilot was used. Measurement started with the patient in the standing position in neutral rotation. Then, the patient achieved in 30° knee flexion under weight-bearing maximal external trunk rotation and returned to the neutral position. The same measurement was done for the internal trunk rotation. For the anterior-posterior stability, KT-1000 arthrometer was used. All measurements were repeated three times for each knee joint.

RESULTS

After the DB reconstruction, the mean external rotation of the tibia (ER) was 8.2° and the internal rotation (IR) was 10.2°. In the contralateral healthy knee joint, ER was 8.5° (p = 0.597) and IR was 12.1° (p = 0.064). After the SB reconstruction, ER was 9.4° and IR was 13.1°. In the contralateral healthy knee joint, ER was 7.7° (p = 0.066) and IR was 9.8° (p = 0.005). Anterior-posterior translation was to the same extent for both groups.

CONCLUSIONS

The DB reconstruction of the ACL restores the rotational stability of the knee joint without any significant difference in comparison to the contralateral healthy knee (p > 0.05). The main finding of this study is that the internal rotational stability of the knee joint after the anatomic SB technique is not sufficient.

Regional Variation in the Mechanical and Microstructural Properties of the Human Anterior Cruciate Ligament

BACKGROUND

The anteromedial (AM) bundle of the anterior cruciate ligament (ACL) has a higher modulus and failure stress than does the posterolateral (PL) bundle. However, it is unknown how these properties vary within each bundle.

PURPOSE

To quantify mechanical and microstructural properties of samples within ACL bundles to elucidate any regional variation across the ligament. We hypothesized that there are no differences within each bundle in contrast to cross-bundle variation.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Sixteen human ACLs were dissected into AM and PL bundles. Three samples were taken from each bundle in an ordered sequence from AM (region 1 AM bundle) to PL (region 6 PL bundle). Each sample was tested in uniaxial tension, using quantitative polarized light imaging (QPLI) to quantify collagen fiber alignment. After preconditioning, samples were subjected to a stress-relaxation (SR) test followed by quasistatic ramp-to-failure (RF). Peak and equilibrium stress values were computed from the SR test and modulus quantified in the toe- and linear-regions of the RF. QPLI values describing collagen orientation (angle of polarization [AoP]) and strength of alignment (degree of linear polarization [DoLP]) were computed for the SR test and at points corresponding to the zero, transition point, and linear region of the RF.

RESULTS

Toe- and linear-region modulus values decreased from region 1 to 6. Slopes of regression lines increased for the average DoLP during RF, with significance at higher strains. The standard deviation of AoP values decreased during RF, indicating tighter distribution of orientation angles, with significant correlations at all points of the RF. During SR, stress values uniformly decreased but did not show significant linear regression by region. DoLP and AoP values changed slightly during SR and demonstrated significant linear variation by region at both peak and equilibrium points.

CONCLUSION

Most microstructural and material properties evaluated in this study appear to follow a linear gradient across the ACL, rather than varying by bundle.

CLINICAL RELEVANCE

This AM-to-PL variation provides a more accurate description of functional tissue anatomy and can be used to assess and guide techniques of ACL reconstruction.

The Results of Single Bundle Versus Double Bundle ACL Reconstruction Surgery, a Retrospective Study and Review of Literature

Objective:

The purpose of this study was to evaluate the results of single bundle and double bundle surgical techniques for anterior cruciate ligament (ACL) reconstruction.

Methods:

In this study, all single bundle and double bundle ACL reconstruction surgeries that were done in our university hospital from January 2008 to December 2012 were enrolled. All patients were followed at 2,6,12, 24 weeks and 1 a 2 years post operatively. On last follow up all patients were evaluated by clinical examination, KT-1000 and Lysholm questionnaire.

Results:

Seventy five patients were operated using single bundle and eighty five patients with double bundle technique. Fifty seven percent of patients in single bundle and 80% of patients in double bundle group had experienced pain during follow-up period. None of cases had knee extension or flexion loss. The average side to side differences using KT-1000 was 3.5 ± 0.38 (2.9-4.1) millimeters in single bundle group and 3.39 ± 0.39 (2.8-4) millimeters in double bundle group. These results showed no significant difference between two groups (P= 0.31). Lysholm score improved significantly in both groups, but there was no significant difference between them.

Conclusion:

According to this study the clinical results of single bundle ACL reconstruction was similar to double bundle reconstruction in short term follow up. Further studies are needed to evaluate the long term results.

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.

Comparison Between Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction With 6- to 8-Stranded Hamstring Autograft: A Prospective, Randomized Clinical Trial

BACKGROUND

Whether double-bundle (DB) anterior cruciate ligament (ACL) reconstruction with 6- to 8-stranded hamstring autograft (HG) is better than single-bundle (SB) ACL reconstruction remains debatable, as long-term follow-up data are lacking.

PURPOSE

To prospectively investigate and compare the long-term results of DB and SB ACL reconstruction with a 6- to 8-stranded HG.

STUDY DESIGN

Randomized controlled clinical trial;

LEVEL OF EVIDENCE

1.

METHODS

A total of 80 patients with chronic ACL rupture were randomized to SB or DB ACL reconstruction with a 6- to 8-stranded HG. In the SB group, both the semitendinosus tendon (ST) and the gracilis tendon (GT) were prepared in 3 or 4 strands, with a total of 6 to 8 strands. In the DB group, the ST was prepared in 3 or 4 strands used for the anteromedial bundle, and the GT was prepared in the same manner for the posterolateral bundle. Each graft was fixed with an EndoButton, a bioabsorbable interference screw, and a staple. Outcome assessment was performed by a blinded independent observer using International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores, as well as range of motion (ROM), Lachman test, pivot-shift test, KT-2000 arthrometer side-to-side difference, and return-to-sport data.

RESULTS

A total of 68 patients (DB group, 34; SB group, 34) were observed for a mean of 80 months (range, 74-86 months). There were 2 traumatic instability failures and two 5° extension restrictions in the DB group, while no failures or 5° extension restrictions were observed in the SB group. The mean Lysholm, Tegner, and IKDC scores improved significantly in both groups compared with preoperation scores (P < .05). No patient had a positive Lachman test result. No significant differences were found between groups in functional scores, incidence of pivot shift, ROM, Lachman test, KT-2000 arthrometer anterior laxity, or time and level of return to sport.

CONCLUSION

Both SB and DB ACL reconstruction with 6- to 8-stranded HG showed satisfactory results in subjective scores and anteroposterior and rotational stability over a nearly 7-year follow-up; neither technique was superior.

Does the hyperextension maneuver prevent knee extension loss after arthroscopic anterior cruciate ligament reconstruction?

Background

Disruption of the anterior cruciate ligament (ACL) is one of the most frequent musculoskeletal injuries affecting physically active men and women. In the United States, an estimated 200,000 ACL reconstructions are performed annually. One of the most common complications of ACL reconstruction is loss of extension. The purpose of this study was to assess the effects of the hyperextension maneuver on preventing knee extension loss after arthroscopic ACL reconstruction.

Materials and methods

In this prospective randomized clinical trial study, 100 adult patients with a documented complete ACL tear were randomized to two groups. All patients underwent arthroscopic ACL reconstruction with quadrupled semitendinosus and gracilis autograft by the senior author based on the same technique and instruments. However, the hyperextension maneuver was only performed in 50 patients during autograft fixation on the tibial side (case group). The postoperative rehabilitation protocol was similar for both groups. The knee range of motion and extension limit was evaluated at 2, 6, 12, and 24 weeks and at 1 year postoperatively.

Results

One hundred patients (88 male and 12 female) aged from 17−36 years (average 26.9 years) were included in our study. The two groups were similar regarding age, sex, and dominant side involvement (P >0.4).The difference between the two groups was significant only at 2 weeks (P <0.02). After 2 weeks, although the rate of limited extension was higher in the control group, no significant difference was seen between the groups.

Conclusion

Although the hyperextension technique during graft fixation on the tibial side may induce better range of motion in the first 2 weeks after ACL reconstruction surgery, this effect is not significant after 2 weeks.

Level of evidence

Therapeutic level II.

Comparison of Graft Failure Rate Between Autografts Placed via an Anatomic Anterior Cruciate Ligament Reconstruction Technique: A Systematic Review, Meta-analysis, and Meta-regression

BACKGROUND

Recent data from the Danish anterior cruciate ligament (ACL) registry demonstrated increased reoperation rates for hamstring tendon autografts when an anatomic ACL reconstruction is performed. This is consistent with reports of greater time needed for hamstring tendon autografts to mature compared with other autografts.

PURPOSE

To review the literature comparing graft failure rate between patellar and hamstring tendon autografts placed anatomically and to determine if there are differences in return to preinjury activity levels between autografts.

STUDY DESIGN

Systematic review with meta-analysis and meta-regression.

METHODS

The PubMed, MEDLINE, SPORTDiscus, and CINAHL databases were used to identify studies published from January 1, 2000, through March 7, 2014. To compare postoperative outcomes between patellar tendon and hamstring tendon autografts, summary event rates for graft failure and return to preinjury activity level were calculated. A meta-analysis was performed to calculate a summary odds ratio (OR) for graft failure between autografts using the studies that directly compared the 2 autografts. Meta-regression analyses were performed to assess the influence of postoperative follow-up time on graft failure rate.

RESULTS

A total of 28 studies reported graft failures for patellar tendon (6 studies) and hamstring tendon (26 studies) autografts used with anatomic ACL reconstruction; 4 of the 28 were comparison studies. Graft failure rate was not significantly different between patellar tendon (7.0% [95% CI, 4.6%-10.5%]) and hamstring tendon autografts (3.9% [95% CI, 2.7%-5.6%]). The odds of graft failure were slightly higher for hamstring tendon autografts (OR, 1.21 [95% CI, 0.63-2.33]), but this difference was not significant (P = .57). The rate of patients returning to preinjury activity levels was not significantly different between patellar (n = 1 study; 58.1% [95% CI, 40.4%-73.9%]) and hamstring tendon autografts (n = 5 studies; 75.6% [95% CI, 43.7%-92.5%]). Overall graft failure rate was positively associated with postoperative follow-up time, but this effect was only significant with hamstring tendon autografts (P < .05).

CONCLUSION

Differences in graft failure rate between patellar tendon and hamstring tendon autografts were not significant. Although follow-up time was only found to have a significant influence on hamstring tendon graft failure rates, this was likely due to the smaller sample of studies assessing patellar tendon graft failures. Differences in return to preinjury activity levels could not be determined due to the lack of studies assessing that outcome. Both patellar and hamstring tendon autografts demonstrate a low risk of failure and moderately high return to activity level after anatomic ACL reconstruction.

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.

The inferior medial genicular artery and its vascularization of the pes anserinus superficialis: A cadaveric study

BACKGROUND

A common method for reconstruction of the anterior cruciate ligament (ACL) is it's replacement by a free avascular graft, using the gracilis and/or semitendinosus tendons. These grafts pass a vulnerable phase in the ligamentization-process during the 1^st year after reconstruction. The aims of this study were first to evaluate the vascularization of the pes anserinus superficialis (PAS) by the inferior medial genicular artery (IMGA) and second to develop a pedunculated surgical technique for ACL reconstruction, to preserve a maximal amount of natural vascularization of the tendons inserting at the PAS.

MATERIALS AND METHODS

First, the vascularization of the PAS was assessed in 12 fresh-frozen lower extremities. The IMGA was identified at its origin at the popliteal artery and perfused with a methylene blue solution. Second, a pedunculated ACL reconstruction was performed in 5 fresh-frozen lower extremities under maintenance of the distal tendon insertion at PAS.

RESULTS

The PAS is a highly vascularized structure. Vessels originate from the IMGA, running along the three tendons of the PAS in the paratendinous tissue. Histologically intratendinous vessels exist; however, perfusion of the inserting tendons through intratendinous vessels was not proven macroscopically. The pedunculated grafts could be positioned and fixed successfully into the bone tunnels in all knees.

CONCLUSION

Although intratendinous vascularization of the tendons of the PAS via the IMGA was not proven, this study indicates a new possibility of ACL reconstruction. The described operation technique can be conducive to shorten the vulnerable phase of the graft-ligamentization after ACL reconstruction.

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.

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.

Comparison of single-bundle versus double-bundle anterior cruciate ligament reconstruction after a minimum of 3-year follow-up: a meta-analysis of randomized controlled trials

Both single-bundle (SB) and double-bundle (DB) procedures have been widely used in the treatment of anterior cruciate ligament (ACL) rupture; however, the optimal repair strategy remains considerably controversial. In this meta-analysis of published studies, we compared the results of these two techniques. After systematic review of electronic databases and websites, a total of 8 RCTs reporting data on 941 subjects were included. The objective and subjective functional recovery outcomes were meta-analyzed. The methodological quality was evaluated using the CBRG scale. The overall pooled data showed superiority in rotational stability, the degree of osteoarthritis (OA) changes, and subjective function score postoperatively in patients managed with DB compared with the SB procedure (pivot shift test, P = 0.02; degree of OA, P = 0.02; Lysholm score, P = 0.04; and Tegner scale, P = 0.002, respectively). However, subgroup analysis suggested no difference between the treatment procedures at long-term follow-up. This meta-analysis demonstrated that the DB technique could result in better rotational stability and higher subjective function score and was effective in preventing OA compared to SB in the mid-term treatment of the injured ACL. Further studies with better design involving larger sample sizes and longer-term follow-up are required.

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.

Differences in the microstructural properties of the anteromedial and posterolateral bundles of the anterior cruciate ligament

BACKGROUND

Tissue properties of the anteromedial (AM) and posterolateral (PL) bundles of the anterior cruciate ligament (ACL) have not been previously characterized with real-time dynamic testing. The current study used a novel polarized light technique to measure the material and microstructural properties of the ACL.

HYPOTHESIS

The AM and PL bundles of the ACL have similar material and microstructural properties.

STUDY DESIGN

Controlled laboratory study.

METHODS

The AM and PL bundles were isolated from 16 human cadaveric ACLs (11 male, 5 female; average age, 41 years [range, 24-53 years]). Three samples from each bundle were loaded in uniaxial tension, and a custom-built polarized light imaging camera was used to quantify collagen fiber alignment in real time. A bilinear curve fit was applied to the stress-strain data of a quasistatic ramp-to-failure to quantify the moduli in the toe and linear regions. Fiber alignment was quantified at zero strain, the transition point of the bilinear fit, and in the linear portion of the stress-strain curve by computing the degree of linear polarization (DoLP) and angle of polarization (AoP), which are measures of the strength and direction of collagen alignment, respectively. Data were compared using t tests.

RESULTS

The AM bundle exhibited significantly larger toe-region (AM 7.2 MPa vs. PL 4.2 MPa; P < .001) and linear-region moduli (AM 27.0 MPa vs. PL 16.1 MPa; P = .017) compared with the PL bundle. Average DoLP values were similar at low strain but were significantly larger (ie, more uniform alignment) for the AM bundle in the linear region of the stress-strain curve (AM 0.22 vs. PL 0.19; P = .036) compared with the PL bundle. The standard deviation AoP values was larger for the PL bundle at both transition (P = .041) and linear-region strain (P = .014), indicating more disperse orientation.

CONCLUSION

Material and microstructural properties of the AM and PL bundles of the ACL differ during loading. The AM bundle possessed higher tissue modulus and failure stress, as well as more uniform fiber alignment under load.

CLINICAL RELEVANCE

These insights into native ligament microstructure can be used to assess graft options for ACL reconstruction and optimize surgical reconstruction techniques.

Prospective randomized comparison of knee stability and joint degeneration for double- and single-bundle ACL reconstruction

PURPOSE

This study aims to determine the outcome of double-bundle anterior cruciate ligament (ACL) reconstruction using an allograft in comparison with ACL reconstruction using a double-bundle autograft or a single-bundle allograft.

METHODS

A total of 424 patients who accepted primary ACL reconstructions were divided randomly into three groups: double-bundle technique with autograft (DB-AU group, n = 154), double-bundle technique with allograft (DB-AL group, n = 128), and single-bundle technique with allograft (SB group, n = 142). The KT-1000 arthrometer and pivot-shift tests were performed at 3, 12, and 36 months after surgery, and clinical outcome measurements include the Lysholm score and the IKDC rating scales. Radiological assessments evaluated arthritic changes and tunnel expansion at 36 months postoperatively.

RESULTS

The KT-1000 test scores in the DB-AU and DB-AL groups were significantly better than those in the SB group at 12 and 36 months postoperatively (P < 0.05). The pivot-shift tests scores in the DB-AU and DB-AL groups were significantly better than those in the SB group at the 3, 12, and 36 month follow-ups (P < 0.05). Based on the IKDC score and Lysholm score, there were no significant difference between the three groups during follow-up (P > 0.05). At 36 months postoperatively, 42.3 % of patients in the SB group showed a progression in arthritic changes, which was greater than in the DB-AU (29.2 %) and DB-AL (27.3 %) groups (P < 0.05). At 36 months, the rates of tunnel expansion in the DB-AU group and the DB-AL group were lower than in the SB group (P < 0.05).

CONCLUSIONS

Double-bundle ACL reconstruction can be used to achieve better anterior and rotational stability and has a lower rate of arthritic progression and tunnel expansion than the single-bundle procedure.

LEVEL OF EVIDENCE

I.

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.

Pain experience and functional outcome of inpatient versus outpatient anterior cruciate ligament reconstruction, an equivalence randomized controlled trial with 12 months follow-up

BACKGROUND

Arthroscopic reconstruction of the anterior cruciate ligament (ACL) has traditionally been performed in an inpatient setting. Outpatient treatment may offer the advantages of cost reduction and higher patient satisfaction.

HYPOTHESIS/PURPOSE

We investigated whether ACL reconstruction in an outpatient setting is equally safe as in an inpatient setting and whether comparable functional outcomes can be achieved. We hypothesized that the outcomes of outpatient ACL reconstruction result in similar outcomes as inpatient ACL reconstruction.

STUDY DESIGN

A prospective randomized controlled trial was conducted at one centre.

METHODS

Forty-six patients were randomized to outpatient treatment or a 2-day admission after ACL reconstruction. The functional outcome was evaluated with the Lysholm, Tegner and International Knee Documentation Committee scores. Safety of the procedures was judged according to pain experience and readmission rate. The duration of follow-up was 1 year after ACL reconstruction. The patients were provided with a simple postoperative analgesic protocol. The linear mixed effect model for repeated measures was used for testing the differences between the study groups.

RESULTS

No significant differences were found between the study groups in all the outcome measures. No readmissions were recorded related to pain. One complication was recorded in the outpatient group versus three in the inpatient group.

CONCLUSION

This study indicates that outpatient care after ACL reconstruction yields comparable functional results and postoperative pain experience as inpatient care and is a safe option. A simple analgesic protocol provides adequate pain relief during the postoperative phase.

LEVEL OF EVIDENCE

I.

Mid- to long-term results of single-bundle versus double-bundle anterior cruciate ligament reconstruction: randomized controlled trial

PURPOSE

To evaluate the mid-to long-term results of a randomized controlled trial of single-bundle (SB) versus double-bundle (DB) anterior cruciate ligament (ACL) reconstruction using a semitendinosus tendon.

METHODS

Seventy-eight patients who underwent primary ACL reconstruction with an autologous semitendinosus tendon were prospectively randomized into 2 groups: SB reconstruction (n = 39) and DB reconstruction (n = 39). In both groups, grafts were fixed at 30° of flexion with a total tension of 80 N. The following evaluation methods were used: clinical examination, KT-1000 arthrometer (MEDmetric, San Diego, CA) measurement, muscle strength, Tegner activity score, Lysholm score, subjective rating scale regarding patient satisfaction and sports performance level, graft retear, contralateral ACL tear, and additional meniscus surgery.

RESULTS

Fifty-three patients (25 in SB group and 28 in DB group) who were followed up for a minimum of 3 years (mean, 69 months; range, 36 to 140 months) were evaluated. Preoperatively, there were no differences between the groups. Postoperatively, the Lachman and pivot-shift test results were better in the DB group (P = .024 and P < .0001, respectively). KT measurements were better in the DB group (mean, 1.4 mm v 2.7 mm; P = .0023). The Tegner score was also better in the DB group (P = .033). There were no significant differences in range of motion, muscle strength, Lysholm score, subjective rating scale, graft retear, and secondary meniscal tear.

CONCLUSIONS

In ACL reconstruction using the transtibial approach, DB reconstruction was significantly better than SB reconstruction regarding anterior and rotational stability during the 3- to 12-year follow-up. The results of KT measurements and the Lachman and pivot-shift tests were significantly better in the DB group, whereas there was no difference in the anterior drawer test results. The Tegner score was also better in the DB group; however, there were no differences in the other subjective findings.

LEVEL OF EVIDENCE

Level II, lesser-quality prospective randomized trial.