Endoscopic versus rear-entry ACL reconstruction: a systematic review

One-incision versus two-incision techniques for arthroscopically assisted anterior cruciate ligament reconstruction in adults

BACKGROUND

Anterior cruciate ligament (ACL) tears are serious knee injuries that are frequently treated surgically in the form of arthroscopically assisted reconstruction with grafts from the patella or hamstrings tendons. We reviewed the evidence for the choice of arthroscopically assisted ACL reconstruction technique in terms of whether it should involve one incision (femoral tunnel drilled from inside the knee joint under arthroscopic visualisation) or two incisions (femoral tunnel drilled from outside to inside the knee joint).

OBJECTIVES

To assess the effects (benefits and harms) of one-incision versus two-incision techniques for arthroscopically assisted ACL reconstruction in adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Latin American and Caribbean Health Sciences (LILACS), the World Health Organization International Clinical Trials Registry Platform, ClinicalTrials.gov, reference lists, and conference abstracts. The date of the search was 16 August 2017.

SELECTION CRITERIA

Randomised and quasi-randomised controlled clinical trials evaluating one-incision versus two-incision techniques for arthroscopically assisted ACL reconstruction in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched and selected studies, and extracted data and assessed the risk of bias of the eligible studies. We undertook limited pooling of data using the fixed-effect model.

MAIN RESULTS

We included five trials (four randomised and one quasi-randomised) evaluating a total of 320 participants who were mainly in their 20s. All participants underwent ACL reconstruction with patella tendon grafts. All five included trials were at a high risk of bias, particularly performance bias. Based on these limitations and the insufficiency of the available data resulting in imprecision of effect estimates, we judged the quality of the evidence as very low for all outcomes. This means that we are uncertain of the findings of the review.We found very low-quality evidence of no clinically important differences between the two techniques in self reported knee function, measured using the Lysholm knee score (scale 0 to 100: best outcome), at short-term (3 months) (mean difference (MD) 2.73 favours one-incision technique, 95% confidence interval (CI) -2.70 to 8.15; 79 participants, 2 studies), intermediate-term (12 months) (MD -3.68 favours two-incision technique, 95% CI -6.61 to -0.75; 79 participants, 2 studies), and long-term follow-up. The data available for long-term follow-up (2 to 5 years) was expressed in terms of the numbers of participants with excellent Lysholm scores (90 points or more); we found no difference between the two groups (42/45 versus 36/40; risk ratio (RR) 1.04, 95% CI 0.91 to 1.18; 1 study). There were no data for quality of life measures or for overall numbers of participants incurring an adverse event. We found very low-quality evidence of little between-group differences in individual adverse events such as infection, knee stiffness, reoperation, and graft failure.We found very low-quality evidence from one study (59 participants) of little difference between the two groups in activity levels measured using Tegner scores (scale 0 to 10: highest sport activity) at two years (MD -0.80 favours two-incision technique, 95% CI -1.90 to 0.30). There was very low-quality evidence from four studies of minimal between-group difference in the number of participants with normal or nearly normal objectively measured knee function (International Knee Documentation Committee objective assessment grading) at intermediate follow-up (means 12 to 28 months): 56/78 versus 63/89; RR 1.01, 95% CI 0.85 to 1.21; 167 participants).

AUTHORS' CONCLUSIONS

The very low-quality and often absent evidence means that we are uncertain whether one-incision arthroscopically assisted ACL reconstruction techniques yield better, worse, or equivalent results compared with two-incision techniques in terms of short-, intermediate-, or long-term subjective function, quality of life, adverse outcomes, activity levels, and objectively rated knee function. The evidence was available only for single-bundle ACL reconstruction using patella tendon grafts.When considering priorities for high-quality randomised trials on techniques for ACL reconstruction, it is important to note the insufficiency of the evidence available to inform this key comparison.

Indications for Two-Incision (Outside-In) Anterior Cruciate Ligament Reconstruction

Anterior cruciate ligament (ACL) reconstruction is a commonly performed procedure. Drilling the femoral tunnel independent of the tibial tunnel has become popular as surgeons strive to create tunnels in the anatomic locations of the femoral and tibial attachments of the native ligament. The 2-incision technique effectively and reproducibly accomplishes this goal. The 2-incision technique for ACL reconstruction is a valuable tool in the skillset of the reconstructive knee surgeon. Indications for the 2-incision surgery are reviewed in detail. Furthermore, technical tips, complications, and outcomes are discussed.

Anatomic placement of the femoral tunnel by a modified transtibial technique using a large-offset femoral tunnel guide: A cadaveric study

BACKGROUND

The purpose of this study was to assess whether the use of a 10 mm-offset femoral tunnel guide with lateral rotation allows more anatomic placement of femoral tunnel compared to the conventional seven millimeters-offset guide in transtibial anterior cruciate ligament (ACL) reconstruction.

METHODS

Sixteen knees from eight cadavers were employed. Four guide pins were inserted using a seven millimeters- or 10mm-offset transtibial femoral tunnel guide with or without lateral rotation technique in each knee. The pin positions were assessed by the quadrant method. Femoral tunnels were then reamed along the guide pins inserted through the laterally rotated guides: seven millimeters-offset for right knees and 10 mm- offset for left knees. The percentages of the coverage of native ACL femoral footprints were analyzed.

RESULTS

Lateral rotation of the seven millimeters- & 10mm-offset guides placed the pins more posteriorly (lower) by 15.7% and 24.5%, respectively (p<0.001). Laterally rotated 10 mm-offset guides placed the guide pins more distally by 6.2% and more posteriorly by 6.6% than laterally rotated seven millimeters-offset guides. Laterally rotated seven millimeters- & 10 mm-offset guides resulted in average coverage of 52.3% and 61.8% of the native ACL femoral footprints, respectively (p<0.001). The lengths of the tunnels were acceptable.

CONCLUSION

Compared to the conventional seven millimeters-offset guide, the use of a 10mm-offset femoral tunnel guide with lateral rotation allows more anatomic placement of femoral tunnel in transtibial ACL reconstruction.

CLINICAL RELEVANCE

Anatomic single bundle ACL reconstruction by transtibial technique seems feasible by using the technique described in this study.

Anatomic Tunnel Placement in Anterior Cruciate Ligament Reconstruction

The anatomic anterior cruciate ligament (ACL) reconstruction concept has developed in part from renewed interest in the insertional anatomy of the ACL, using surgical techniques that can reproduce this anatomy reliably and accurately during surgical reconstruction. Several technical tools are available to help identify and place the tibial and femoral grafts anatomically, including arthroscopic anatomic landmarks, a malleable ruler device, and intraoperative fluoroscopy. The changes in technique for anatomic tunnel placement in ACL reconstruction follow recent biomechanical and kinematic data that demonstrate improved time zero characteristics. A better re-creation of native ACL kinematics and biomechanics is achieved with independent femoral drilling techniques that re-create a central footprint single-bundle ACL reconstruction or double-bundle reconstruction. However, to date, limited short-term and long-term clinical outcome data have been reported that support using either of these techniques rather than a transtibial drilling technique. This lack of clear clinical advantage for femoral independent and/or double-bundle techniques may arise because of the potentially offsetting biologic incorporation challenges of these grafts when placed using these techniques or could result from modifications made in traditional endoscopic transtibial techniques that allow improved femoral and tibial footprint restoration.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

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

RESULTS

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

CONCLUSION

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

Short-Term Study of the Outcome of a New Instrument for All-Inside Double-Bundle Anterior Cruciate Ligament Reconstruction

PURPOSE

The purpose of this study was to evaluate the short-term clinical results and location of the bone tunnel with a new surgical procedure for all-inside double-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

The double-bundle ACL reconstruction procedure was performed in 24 patients (13 male and 11 female patients) with a mean age of 31.0 years. Anterior and posterior tibial translation using an arthrometer (KT-1000; MEDmetric, San Diego, CA) and the Lysholm score were measured before surgery and at a mean of 24.8 months (range, 13 to 45 months) postoperatively. Computed tomography scans were taken to evaluate the bone tunnel positions using 3-dimensional images with the quadrant method for the femoral tunnel and Stäubli's technique for the tibial tunnel.

RESULTS

Three-dimensional computed tomography scans showed that the anteromedial and posterolateral tunnels were placed in anatomically appropriate positions. Arthrometric measurements showed that the mean side-to-side differences were 5.3 mm (SD, 1.6 mm) preoperatively and 0.05 mm (SD, 0.7 mm) at a mean of 24.8 months postoperatively, indicating a remarkable improvement (P < .00001). The mean Lysholm score was 56.3 points (SD, 14.8 points) preoperatively and 95.5 points (SD, 3.8 points) at final follow-up and was significantly improved after the operation (P < .00001).

CONCLUSIONS

The all-inside double-bundle ACL reconstruction technique used in this study resulted in the creation of tunnels in an anatomically appropriate position. Short-term clinical follow-up showed improvement in patient-reported outcomes and knee stability. This technique may provide an alternative option for all-inside ACL reconstruction.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Transtibial versus independent drilling techniques for anterior cruciate ligament reconstruction: a systematic review, meta-analysis, and meta-regression

BACKGROUND

While numerous cadaveric, in vivo, and clinical studies have compared transtibial and independent drilling of femoral tunnels during anterior cruciate ligament reconstruction, there is no evidence-based consensus on which technique affords the best outcome.

HYPOTHESIS

There is no difference in clinical outcome between transtibial and independent drilling of femoral tunnels.

STUDY DESIGN

Systematic review with meta-analysis and meta-regression.

METHODS

Cadaveric, in vivo, and clinical studies comparing transtibial and independent drilling techniques were systematically identified. A qualitative synthesis of nonrandomized studies and meta-analysis of randomized controlled trials (RCTs) were performed. In addition, a meta-regression analysis of RCTs that did not directly compare drilling techniques was performed.

RESULTS

A total of 49 studies were included in the qualitative review, and 15 were included in the meta-analysis; 22 studies were included in the meta-regression. In biomechanical studies, independent drilling placed the center of the femoral tunnel closer to the center of the femoral footprint (mean difference, 2.69 mm; 95% CI, 0.46-4.92; P < .00001). Independent drilling reduced anterior tibial translation with the Lachman examination (mean difference, 2.2 mm; 95% CI, 0.34-4.07; P = .02), 134 N of anterior load (mean difference, 1 mm; 95% CI, 0.29-1.71; P = .006), and simulated pivot shift (mean difference, 3.36 mm; 95% CI, 1.88-4.85; P < .00001). The meta-analysis showed improved Lysholm scores with independent drilling (mean difference, -0.62 points; 95% CI, -1.09 to -0.55; P = .009), although the clinical relevance of this small difference is questionable. There were no significant differences in International Knee Documentation Committee (IKDC) objective scores or Tegner scores between groups. With the meta-regression, there were no significant differences in failure rates or IKDC objective scores.

CONCLUSION

While there are biomechanical data suggesting improved knee stability and more anatomic graft placement with independent drilling, no significant clinical differences were found between the 2 techniques.

CLINICAL RELEVANCE

The current evidence shows that transtibial and independent drilling techniques have equivalent clinical outcomes at short-term to midterm follow-up. The long-term effects of subtle differences in tunnel position and postoperative knee kinematics should be further studied in dedicated, prospective cohort and randomized studies.

Prognosis and predictors of ACL reconstructions using the MOON cohort: a model for comparative effectiveness studies

Injury to the anterior cruciate ligament (ACL) threatens an active lifestyle and exposes the patient to risk of early osteoarthritis (OA). ACL reconstruction is typically chosen by individuals to allow a return to their previous work and sports activities. Primary ACL reconstruction (ACLR) has in general been effective at restoring functional stability, but patients' modifiable predictors of both short- and long-term validated outcomes and OA are largely unknown. The Multicenter Orthopaedic Outcomes Network (MOON) consortium was established in 2002 to enroll and longitudinally follow a population cohort of ACL reconstructed patients. The objective was to establish patient-specific predictive models of clinically important outcomes. Over the past 10 years, the overarching aims of this NIAMS-funded prospective multicenter cohort of ACL reconstructions has been threefold: (1) to identify both short- and long-term prognosis and predictors of sports function, activity level, and general health through validated patient-reported outcomes, (2) to identify the symptoms and signs of OA, and (3) to quantify the incidence of ACL reconstruction graft and/or contralateral ACL failures and additional surgical procedures. This manuscript summarizes the Kappa Delta Ann Doner Vaughan Award paper and presentation at the 2012 ORS/AAOS Annual Meeting.

The relationship between femoral tunnels created by the transtibial, anteromedial portal, and outside-in techniques and the anterior cruciate ligament footprint

BACKGROUND

Tunnels created for reconstruction of a torn anterior cruciate ligament (ACL) are critical determinants of joint stability and clinical outcomes. There is limited objective evidence on the ability of transtibial (TT), anteromedial (AM) portal, and outside-in (OI) operative techniques in creating anatomic tunnels.

HYPOTHESIS

(1) Tibial tunnel-independent techniques can create tunnels more accurately at the anatomic ACL footprint center than the TT technique, and (2) femoral tunnel exit location of the OI and TT techniques on the lateral cortex will be significantly further away from the lateral epicondyle than the femoral tunnel exit location of the AM portal technique.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight cadaveric knee specimens with a mean age of 56 years were used in this study. A digitizing system was used to record points along the outlines of the ACL insertion area and apertures of tunnels created by the TT, AM portal, and OI techniques. The following parameters were measured from the digitized points: (1) amount of ACL, anteromedial bundle, and posterolateral bundle coverage by the tunnels; (2) relationship between the centers of the ACL and the tunnels; and (3) distance between the center of the femoral tunnel exit and the lateral epicondyle. All the recorded parameters were analyzed in 3-dimensional solid modeling software.

RESULTS

The percentage of ACL footprint coverage achieved by all 3 surgical techniques was not significantly different from one another. However, larger femoral posterolateral bundle coverage was observed in tunnels created by the AM portal and OI techniques than in the TT tunnel. In terms of anteromedial bundle coverage, no significant differences were observed between the 3 techniques. On average, 27.1% ± 17.4% of the TT tunnel was outside the ACL footprint. This was significantly larger compared with 13.6% ± 15.7% with the AM portal technique (P = .01) and 10.8% ± 10.8% in the OI technique (P = .01). Centers of femoral tunnels created by the TT, AM portal, and OI techniques were located at a distance of 3.0 ± 1.5 mm, 2.1 ± 0.9 mm, and 1.5 ± 1.2 mm, respectively, from the ACL footprint center. The femoral tunnel exit location of the AM portal technique on the lateral femoral cortex was closer to the lateral epicondyle than the femoral tunnel exit location of the OI and TT techniques.

CONCLUSION

Findings of this study indicate that a larger posterolateral bundle coverage is achieved by the AM portal and OI techniques than by the TT technique. Centers of the tunnels created by the AM portal and OI techniques were closer to the native ACL footprint center than the center of the TT technique tunnel. The incidence of a posterior femoral tunnel exit relative to the lateral epicondyle is higher in the AM portal technique than in the OI and TT techniques.

CLINICAL RELEVANCE

For ACL reconstruction using soft tissue grafts, tibial tunnel-independent techniques can produce more anatomic tunnels than the TT technique.

Biomechanical evaluation of knee joint laxities and graft forces after anterior cruciate ligament reconstruction by anteromedial portal, outside-in, and transtibial techniques

BACKGROUND

Recently, anatomic anterior cruciate ligament (ACL) reconstruction is emphasized to improve joint laxity and to potentially avert initiation of cartilage degeneration. There is a paucity of information on the efficacy of ACL reconstructions by currently practiced tunnel creation techniques in restoring normal joint laxity.

STUDY DESIGN

Controlled laboratory study.

HYPOTHESIS

Anterior cruciate ligament reconstruction by the anteromedial (AM) portal technique, outside-in (OI) technique, and modified transtibial (TT) technique can equally restore the normal knee joint laxity and ACL forces.

METHODS

Eight fresh-frozen human cadaveric knee specimens were tested using a robotic testing system under an anterior tibial load (134 N) at 0°, 30°, 60°, and 90° of flexion and combined torques (10-N·m valgus and 5-N·m internal tibial torques) at 0° and 30° of flexion. Knee joint kinematics, ACL, and ACL graft forces were measured in each knee specimen under 5 different conditions (ACL-intact knee, ACL-deficient knee, ACL-reconstructed knee by AM portal technique, ACL-reconstructed knee by OI technique, and ACL-reconstructed knee by TT technique).

RESULTS

Under anterior tibial load, no significant difference was observed between the 3 reconstructions in terms of restoring anterior tibial translation (P > .05). However, none of the 3 ACL reconstruction techniques could completely restore the normal anterior tibial translations (P < .05). Under combined tibial torques, both AM portal and OI techniques closely restored the normal knee anterior tibial translation (P > .05) at 0° of flexion but could not do so at 30° of flexion (P < .05). The ACL reconstruction by the TT technique was unable to restore normal anterior tibial translations at both 0° and 30° of flexion under combined tibial torques (P < .05). Forces experienced by the ACL grafts in the 3 reconstruction techniques were lower than those experienced by normal ACL under both the loading conditions.

CONCLUSION

Anterior cruciate ligament reconstructions by AM portal, OI, and modified TT techniques are biomechanically comparable with each other in restoring normal knee joint laxity and in situ ACL forces.

CLINICAL RELEVANCE

Anterior cruciate ligament reconstructions by AM portal, OI, and modified TT techniques result in similar knee joint laxities. Technical perils and pearls should be carefully considered before choosing a tunnel creating technique.

The rationale for identifying clinical predictors modifiable by tissue engineering for translational models

This article proposes a "bedside-to-bench" approach as a model to improve clinical outcomes for patients through functional tissue engineering (TE). The link between the highest level of clinical research and evaluation criteria for musculoskeletal TE is in identifying clinically proven predictors that are amenable to functional TE. The TE solutions developed in the laboratory should then be tested in translational models to evaluate efficacy and safety prior to controlled clinical trials. The best available evidence for potentially decreasing the incidence of radiographically confirmed osteoarthritis after anterior cruciate ligament injury is preservation of meniscus function. Meniscus tears occur concurrently in approximately 50% of anterior cruciate ligament tears. TE could promote repair of torn meniscus and/or replacement of meniscus loss because meniscus tear is a proven predictor of clinically relevant outcomes (such as osteoarthritis) in patients and is amenable to a potential TE solution.

Anteromedial portal versus transtibial drilling techniques in ACL reconstruction: a blinded cross-sectional study at two- to five-year follow-up

Drilling of the femoral tunnel with the transtibial (TT) technique is widely used in bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction. Recent studies suggest higher knee stability with the use of the anteromedial portal (AMP). The purpose of this study was to compare functional and clinical outcomes of BPTB ACL reconstruction using the TT or the AMP technique for drilling the femoral tunnel. All ACL reconstructions between January 2003 and April 2006 were approached for eligibility. Forty-seven patients met inclusion criteria (21 TT group and 26 AMP group). Blinded assessments of IKDC score, knee stability and range of motion, one-leg hop test, mid-quadriceps circumference, VAS for satisfaction with surgery, Lysholm and Tegner scores, and SF-12 questionnaire were obtained for both groups. Data on preoperative and postoperative surgical timing were retrospectively reviewed through the charts. The AMP group demonstrated a significantly lower recovery time from surgery to walking without crutches (p < 0.01), to return to normal life (p < 0.03), to return jogging (p < 0.03), to return training (p < 0.03), and to return to play (p < 0.03). Knee stability values measured with KT-1000, Lachman test, pivot-shift sign, and objective IKDC score assessments were significantly better for the AMP compared to TT group (p < 0.002, p < 0.03, p < 0.02, p < 0.015, respectively). No differences were found for VAS for satisfaction with surgery, Lysholm, Tegner, and SF-12 between both groups. The use of the AMP technique significantly improved the anterior-posterior and rotational knee stability, IKDC scores, and recovery time from surgery compared to the TT technique.