Anteromedial Portal Technique Research Articles

Transtibial versus anteromedial transportal femoral tunnel in single-bundle anterior cruciate ligament reconstruction: a systematic review and meta-analysis of prospective randomized controlled trials.

The purpose of this study was to systematically review and meta-analyze randomized controlled trials (RCTs) reporting the comparative clinical and functional outcomes, postoperative complications, and radiological outcomes of single-bundle anterior cruciate ligament reconstruction (ACLR) performed using the transtibial (TT) approach or anteromedial (AM) technique. A systematic review of the literature was performed according to Cochrane and PRISMA guidelines. RCTs comparing TT and AM techniques were considered only. The quality of the studies was defined using the GRADE system, and the risk of bias was assessed with the RoB 2 tool. The primary endpoint was to systematically review and meta-analyze the clinical outcomes, residual laxity and failure rate of both AM and TT techniques. In the current meta-analysis 13 RCTs involving 989 patients who underwent arthroscopic single-bundle ACLR (486 TT and 503 AM) were included. Patients undergoing AM technique resulted in higher objective-IKDC (p < 0.001) and Lysholm scores (p = 0.002), despite a lower incidence of pathologicalanterior tibial translation (p < 0.001) and positive pivot-shift test (p < 0.001). No differences were detected in IKDC subjective score (p = 0.26), Tegner activity scale (p = 0.18) and graft failure (p = 0.07). ACL reconstruction through AM portal technique provides better clinical outcomes and lower incidence of residual rotational and anteroposterior laxity in comparison with the TT technique. No statistically significant difference in subjective outcomes and graft failure was reported.

Young men undergoing anterior cruciate ligament reconstruction with patellar tendon autograft and anteromedial drilling outperform at 5- to 10-year follow-up in terms of graft stability and activity levels compared to those undergoing reconstruction with hamstring autograft and transtibial drilling

ObjectiveTo compare 5- to 10-year outcomes of anterior cruciate ligament (ACL) reconstruction in young men performed with bone-patellar tendon bone (BPTB) autograft and anteromedial portal to reconstruction with hamstring autograft and transtibial technique. It was hypothesised that in young adult men, at 5- to 10-year follow-up, superior restoration of knee laxity and activity levels would be demonstrated using BPTB autograft and anteromedial portal technique. MethodsNinety-four men who had ACL reconstruction with BPTB autograft and anteromedial portal were eligible for comparison to 106 men who had reconstruction with hamstring autograft and transtibial technique. Inclusion criteria were: (1) age 18–35 years, (2) ACL tear caused by sports trauma only, (3) no concomitant ligament reconstruction and (4) 5- to 10-year follow-up. Outcome measures compared between the two groups included Lachman and pivot shift tests, KT side-to-side difference, Tegner and Marx scores, International Knee Documentation Committee (IKDC)-subjective score, Knee Osteoarthritis Outcome Scale (KOOS), Short Form (SF)-36, and single hop test for distance. P value ​< ​0.05 indicated statistical significance. ResultsForty-five patients with BPTB and 55 patients with hamstring ACL reconstruction were available for in-person assessment at 5–10 years after surgery. Outcomes in the BPTB group compared to the hamstring group showed KT difference 1.4 ​± ​1.9 mm vs. 2.8 ​± ​2.3 mm (p ​< ​0.01), pivot shift grade 2–3 in 4% vs. 34% (p ​< ​0.01), return to preinjury Tegner level in 51% vs. 36% (p ​= 0.1) and to preinjury Marx score in 29% vs. 11% (p ​= 0.02), and IKDC-subjective 88 ​± ​10 vs. 82 ​± ​13 vs (p ​< ​0.01), respectively. Statistically significant inter-relationships were found between KT side-to-side difference and the Tegner, Marx and IKDC-subjective scores at follow-up (r ​= ​−0.314, p ​< ​0.01; r ​= ​−0.263, p ​< ​0.01; r ​= ​−0.218, p ​= ​0.03, respectively). ConclusionYoung men undergoing ACL reconstruction with patellar tendon autograft and anteromedial drilling outperform at 5- to 10-year follow-up in terms of graft stability and activity levels compared to young men undergoing reconstruction with hamstring autograft and transtibial drilling. Level of EvidenceIII (Retrospective cross-sectional comparative study).

Robotic-assisted anatomic anterior cruciate ligament reconstruction: a comparative analysis of modified transtibial and anteromedial portal techniques in cadaveric knees.

Introduction: This study employed surgical robot to perform anatomic single-bundle reconstruction using the modified transtibial (TT) technique and anteromedial (AM) portal technique. The purpose was to directly compare tunnel and graft characteristics of the two techniques. Methods: Eight cadaveric knees without ligament injury were used in the study. The modified TT and AM portal technique were both conducted under surgical robotic system. Postoperative data acquisition of the tunnel and graft characteristics included tibial tunnel position, tunnel angle, tunnel length and femoral tunnel-graft angle. Results: The mean tibial tunnel length of the modified TT technique was significantly shorter than in the AM portal technique (p < 0.001). The mean length of the femoral tunnel was significantly longer for the modified TT technique than for the AM portal technique (p < 0.001). The mean coronal angle of the tibial tunnel was significantly lower for the modified TT technique than for the AM portal technique (p < 0.001). The mean coronal angle of the femoral tunnel was significantly lower for the AM portal technique than for the modified TT technique (p < 0.001). The AM portal technique resulted in a graft bending angle that was significantly more angulated in the coronal (p < 0.001) and the sagittal planes (p < 0.001) compared with the modified TT technique. Discussion: Comparison of the preoperative planning and postoperative femoral tunnel positions showed that the mean difference of the tunnel position was 1.8 ± 0.4mm. It suggested that the surgical navigation robot could make predictable tunnel position with high accuracy. The findings may support that the modified TT technique has benefits on femoral tunnel length and obliquity compared with AM portal technique. The modified TT technique showed a larger femoral tunnel angle in the coronal plane than the AM portal technique. Compared with the modified TT technique, the more horizontal trajectory of the femoral tunnel in the AM portal technique creates a shorter femoral tunnel length and a more acute graft bending angle.

All-Inside ACL Reconstruction: Short Femoral and Tibial Socket Technique

Background: Recently, there has been an increase in interest in all-inside anterior cruciate ligament (ACL) reconstruction (ACLR). Regarding graft maturity, graft contact with the bone tunnel is important. All-inside ACLR with short femoral and tibial sockets might allow to increase the contact between the graft and the socket (ie, no interference screw and contact between the graft and bottom of the socket) and can improve graft maturing. Indications: All-inside ACLR with short sockets technique is indicated in patients with primary ACL rupture or ACL graft re-rupture. Technique Description: The patient was placed in supine position. Following examination under anesthesia, diagnostic arthroscopy was performed to assess for meniscus injuries and chondral defects. The surgical technique required 6 steps: (1) graft preparation (4-strand semitendinosus tendon, graft length was about 45 mm, grafts larger than 8 mm), (2) creating femoral socket (5-10 mm), (3) creating tibial tunnel socket (10-15 mm), (4) passing the graft, (5) tensioning the graft, and (6) graft fixation and skin closure. Patients were partial weightbearing with crutches for 3 weeks and used a hinged knee brace for 6 weeks after surgery. Return to activities was based on functional strength recovery, with a return to running targeted at 4 to 5 months after surgery. Results: All-inside ACLR with short sockets technique provides a better chance of return to preinjury level of activity with accompanied patient satisfaction as compared with anteromedial portal technique at 2 years of follow-up. This technique has favorable functional and clinical outcomes with improvement of graft maturing. Discussion/Conclusion: In conclusion, we propose that ACLR with short tibial and femoral socket technique is simple and safe with favorable clinical outcomes. This is an advantageous ACLR technique that can preserve the gracilis muscle and reduce muscle strength loss of affected limbs. In addition, the all-inside technique is circumferential filling of the socket with the graft, which might increase bone to graft contact compared with interference screws. Further study is needed to show the better clinical outcome and the earlier graft maturation compared with ordinary ACLR. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Anterior Cruciate Ligament Reconstruction Using Bone–Patellar Tendon–Bone Autograft With Lateral Compartment Meniscectomy or Chondroplasty Does Not Lead to Decreased Return to Sport and Activity Compared With No Lateral Pathology

PurposeTo investigate the influence of lateral meniscal and cartilage pathology on the outcome after ACL reconstruction in patients who participate in pivoting sports. MethodsUsing a single surgeon patient registry, patients undergoing an ACL reconstruction (ACLR) using BTB autograft were evaluated with minimum 2-year patient reported outcomes evaluated using Marx, Tegner, Lysholm, and International Knee Documentation Committee (IKDC) scales. Patients were divided into three groups: isolated ACL surgery, ACLR with a partial lateral meniscectomy, or a ACLR with partial lateral meniscectomy and lateral compartment chondroplasty. ResultsA total of 98 patients met inclusion criteria. Using the isolated ACL reconstruction group as a control, Marx scores were higher in patients who additionally underwent a partial lateral meniscectomy at 1-year (p=0.016). There were no significant differences between the ACL only group and the ACL with partial lateral meniscectomy and chondroplasty group. Within the partial meniscectomy cohort comparing the red-white zone tears to the white-white zone tear patients, there were no significant differences when compared with the ACL only control. There were no significant differences appreciated between groups using the IKDC, Lysholm, andTegner scales. ConclusionACL reconstruction using BTB autograft with anteromedial portal drilling technique does not have any significant short-term (2-year outcome) differences in return to activity and patient reported outcomes compared to if patients additionally have a partial lateral meniscectomy and/or lateral compartment chondroplasty. Additional partial lateral meniscectomy showed significantly higher Marx scores at 1 and 2 years post-operatively. Level of Evidence3, Retrospective Cohort Study

The Posterior Tibial Slope Is Not Associated With Graft Failure and Functional Outcomes After Anatomic Primary Isolated Anterior Cruciate Ligament Reconstruction

Background: Biomechanical studies have shown that an increased medial posterior tibial slope (MPTS) may affect anteroposterior knee laxity and tibial shear forces, ultimately increasing the risk for graft failure after anterior cruciate ligament (ACL) reconstruction. Previous clinical studies have, however, reported inconclusive results. Purpose: The purpose of this study was to evaluate the relationship between the MPTS and graft failure as well as functional outcomes after anatomic primary isolated ACL reconstruction using a hamstring tendon autograft. It was hypothesized that an increased MPTS would be associated with a higher ACL graft failure rate. Furthermore, a higher MPTS would negatively correlate with functional outcomes in patients without ACL graft failure. Study Design: Case-control study; Level of evidence, 3. Methods: Consecutive patients who underwent isolated primary ACL reconstruction with an anteromedial portal drilling technique between January 2011 and December 2019 were retrospectively reviewed. The MPTS was measured on preoperative lateral knee radiographs. At a minimum of 24 months postoperatively, the ACL graft failure rate and patient-reported outcome measures (PROM; International Knee Documentation Committee subjective knee form, Lysholm score, Tegner Activity Scale, visual analog scale for pain and subjective instability) were evaluated. Differences in the MPTS between patients with and without ACL graft failure as well as the frequency of graft failure between those with an MPTS <12° and those with an MPTS ≥12° were assessed for statistical significance. Binary logistic regression analysis was performed to stratify the risk of graft failure with the following variables: MPTS, age at surgery, and sex. Correlation analysis was performed to evaluate the relationship between the MPTS and PROM in patients without ACL graft failure. Results: In total, 326 patients were included (median follow-up, 71.0 months [IQR, 49.0-104.0 months]). There was no significant difference in the MPTS between patients with and without graft failure (10.6°± 3.2° vs 11.2°± 2.8°, respectively; P = .264). Additionally, there was no significant difference in the frequency of graft failure between patients with an MPTS <12° and those with an MPTS ≥12° (15.6% vs 16.5%, respectively; P = .835). Binary logistic regression showed that younger age at the time of surgery (odds ratio, 1.069 [95% CI, 1.031-1.109]) was associated with graft failure; sex and MPTS were not associated with graft failure. In patients without ACL graft failure, there was no significant correlation between the MPTS and PROM. Conclusion: In patients who underwent anatomic primary isolated ACL reconstruction, an increased MPTS was not associated with a higher rate of graft failure or inferior functional outcomes. Younger age was a significant nonmodifiable risk factor for ACL graft failure.

Poster 305: Hybrid Transtibial Technique for Femoral Tunnel Drilling in Anterior Cruciate Ligament Reconstruction: A Retrospective, Matched Comparison Study to Anteromedial Portal and Transtibial Approaches

Objectives: Improved biomechanical and clinical outcomes have been reported when femoral anterior cruciate ligament (ACL) tunnels are centered on the native footprint. The anteromedial portal (AMP) technique achieves improved aperture position when compared to a transtibial (TT) approach but sacrifices technical ease and creates a shorter more angulated tunnel. A hybrid transtibial technique (HTT) using medial portal guidance of a flexible transtibial guide wire may combine the strengths of both the AM and TT approaches while mitigating the technical challenges of both techniques. The purpose of our study was to evaluate the clinical efficacy of ACLR using a HTT technique for femoral tunnel drilling in comparison to matched cohorts of AMP and TT drilling approaches in terms of failure/revision requirements and patient-reported outcomes. Methods: A database consisting of all patients with isolated ACL tear and primary reconstruction at a single center between 2005 and 2020 was retrospectively reviewed. Inclusion criteria were patients age ³ 13 years at the time of index ACL reconstruction (ACLR), isolated ACL tear with/without concomitant meniscal/chondral pathology and had minimum 2 year ³ postoperative follow-up. Patients with open physes, prior surgical intervention on the ipsilateral knee, chondral pathology treated with high tibial osteotomy/distal femoral osteotomy, treated for other concurrent ligamentous pathology were excluded. Patients treated with the AMP, TT, and HTT approach meeting inclusion criteria were matched based on age ± 3 years, same sex, and body mass index (BMI) ± 3 Kg/m2. Demographical data (Table 1), surgical data, plain radiographic femoral tunnel angle measurements on anteroposterior and lateral films, postoperative complications and reoperation/revision rates, and patient reported outcome (PRO) scores were collected and reported for each of the three cohorts. Results: A total of 495 patients were included; 170 patients underwent ACLR using the HTT approach, 162 using AMP approach, and 163 using the TT approach. The most common graft of choice for HTT technique was bone patellar tendon bone (BPTB) (162/170 [95.3%]) and for AMP (131/162 [80.9%] and TT (158/163 [96.9%]) technique was hamstring (Table 2). The median (IQR) femoral tunnel angle on sagittal plane showed significant differences between HTT 40° (34°, 46°) and TT 32° (27°, 38°) cohorts ( P- value &lt; 0.0001) (Table 3). On coronal plane the median (IQR) femoral tunnel angles showed significant differences between HTT 47° (42°, 52°) and for both AMP 44° (33°, 54°) and TT 55° (47°, 60°) cohorts ( P- value: 0.001 and &lt;0.001 respectively. Recurrent ACL injury in the ipsilateral knee was experienced in 3/170 (1.8%) HTT patients, 6/162 (3.7%) AMP patients, and 6/163 (3.7%) TT patients at minimum 2-year clinical follow-up (Table 4). When patients were surveyed via phone or email questionnaires, 6/170 (7.4%) HTT, 11/163 AMP (20%), and 18/162 (24.3%) TT patients responded to having further ACLR procedures. The Knee injury and Osteoarthritis Outcome Score (KOOS) pain score and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) function and total scores were found to be statistically significant between HTT and TT technique patients. All other PRO scores showed comparable scores between HTT patients when compared with AMP and TT patients. Conclusions: Patients that underwent ACLR with HTT approach had lower failure/revision rates and comparable or better PRO scores at medium-term follow-up when compared to AMP and TT approach. [Table: see text][Table: see text][Table: see text][Table: see text]

The Hybrid Transtibial Technique Using the LARS Device in Primary Anterior Cruciate Ligament Reconstruction

Background: The recently published hybrid transtibial technique (HTT) using the Pathfinder Guide with a flexible transtibial technique (TT) guide wire may represent a beneficial combination of both the anteromedial portal and TT technique. The HTT has been described as especially suitable for anterior cruciate ligament (ACL) reconstruction in adolescents or ACL revision. However, we also found that the HTT worked for primary ACL reconstruction in adults also using the Ligament Advanced Reinforcement System (LARS). Indications: Acute ACL rupture in active patients who are eager to return to sports quickly. Technique Description: The HTT combined with the conventional LARS reconstruction procedure improves the placement of the femoral tunnel, which involves a guiding vessel clamp through the anteromedial portal combined with a 2.0 mm Kirschner wire via the tibial tunnel. Finally, we used a metal screw for fixation of the ligament. Results: The patient experienced satisfactory reconstruction of his ACL and regained active range of motion in 1 month and a full return to sports in 6 months. Discussion/Conclusion: The HTT using the LARS for primary ACL reconstruction is easy, safe, and reproducible. This combined technique has not yet been published and it may provide good functional results that allow patients to recover quickly and return to sports as soon as possible. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

The "N+10 Rule" to Avoid Graft-Tunnel Mismatch in Bone-Patellar Tendon-Bone ACL Reconstruction Using Independent Femoral Tunnel Drilling.

Graft-tunnel mismatch (GTM) is a common problem in anterior cruciate ligament (ACL) reconstruction (ACLR) using bone-patellar tendon-bone (BPTB) grafts. Application of the "N+10 rule" in endoscopic ACLR with BPTB grafts will result in acceptable tibial tunnel length (TTL), minimizing GTM. Controlled laboratory study. Endoscopic BPTB ACLR was conducted on the paired knees of 10 cadaveric specimens using 2 independent femoral tunnel drilling techniques-accessory anteromedial portal and flexible reamer. The graft bone blocks were trimmed to 10 × 20 mm, and the intertendinous distance (represented by "N") between the bone blocks was measured. The N+10 rule was used to set the angle of the ACL tibial tunnel guide to the appropriate number of degrees for drilling. The amount of excursion or recession of the tibial bone plug in relation to the anterior tibial cortical aperture was measured in both flexion and extension. A GTM threshold of ±7.5 mm was set based on prior studies. The mean BPTB ACL intertendinous distance was 47.5 ± 5.5 mm. The mean measured intra-articular distance was 27.2 ± 3 mm. Using the N+10 rule, the mean total (flexion plus extension) GTM was 4.3 ± 3.2 mm (GTM in flexion, 4.9 ± 3.6 mm; GTM in extension, 3.8 ± 3.5 mm). In 18 of 20 (90%) cadaveric knees, the mean total GTM fell within the ±7.5-mm threshold. When comparing the actual measured TTL to the calculated TTL, there was a mean difference of 5.4 ± 3.9 mm. When comparing femoral tunnel drilling techniques, the total GTM for the accessory anteromedial portal technique was 2.1 ± 3.7 mm, while the total GTM for the flexible reamer technique was 3.6 ± 5.4 mm (P = .5). The N+10 rule resulted in an acceptable mean GTM in both flexion and extension. The mean difference between the measured versus calculated TTL using the N+10 rule was also acceptable. The N+10 rule is a simple and effective intraoperative strategy for achieving desired TTL regardless of patient-specific factors to avoid excessive GTM in endoscopic BPTB ACLR using independent femoral tunnel drilling.

The incidence of deep vein thrombosis after anterior cruciate ligament reconstruction: An analysis using routine ultrasonography of 260 patients.

Recent studies regarding deep vein thrombosis (DVT) after anterior cruciate ligament (ACL) reconstruction investigated only symptomatic complications. The purpose of this study was to assess the true incidence of DVT after ACL reconstruction, regardless of symptom manifestation. Medical records of 260 patients who underwent isolated ACL reconstruction between January 2014 and December 2019 were retrospectively reviewed. Regardless of symptom manifestation, DVT was examined for all patients at 1 week postoperatively using ultrasonography. Demographics, injury mechanism (high energy direct injury and low energy indirect injury), soft tissue injury, preoperative anterior laxity, tourniquet time, and surgical technique (transtibial, anteromedial portal, and outside-in techniques) were investigated. Soft tissue injury was evaluated on magnetic resonance imaging (MRI) scans, based on the Tscherne classification. Risk factors for proximal DVT were identified using logistic regression analyses. A total of 21 (8.1%) patients showed DVT. 5 (1.9%) patients had thrombosis at the popliteal vein; however, none of them exhibited symptoms. The other 16 patients had thrombosis at the distal veins: 1 patient at the anterior tibial vein, 5 patients at the posterior tibial vein, 3 patients at the peroneal vein, 6 patients at the soleal vein, and 1 patient at the muscular branch vein. The risk factors for proximal DVT included high energy direct injury (p = 0.013, odds ratio = 10.62) and grade 2 soft tissue injury (p = 0.039, odds ratio = 6.78). The true incidence of DVT, including symptomatic and asymptomatic complications, were 8.1% after ACL reconstruction. This rate is higher than the previously known incidence which has been investigated only for symptomatic patients. Injury mechanism and soft tissue injury should be assessed when considering thromboprophylaxis.

Anteromedial Portal Technique, but Not Outside-in Technique, Is Superior to Standard Transtibial Technique in Knee Stability and Functional Recovery After Anterior Cruciate Ligament Reconstruction: A Network Meta-analysis

To compare the postoperative outcomes of 4 different femoral drilling techniques in anterior cruciate ligament reconstruction. Three databases were searched for randomized controlled trials comparing any 2 or more of the following femoral drilling techniques in anterior cruciate ligament reconstruction: standard transtibial (sTT), anteromedial portal (AMP), outside-in (OI), or modified transtibial (mTT) technique. A Bayesian network meta-analysis was performed to assess postoperative stability and functional recovery in terms of the side-to-side difference (measured by arthrometry), Lachman test, pivot-shift test, International Knee Documentation Committee subjective and objective scores, Lysholm score, and Tegner score. The Fisher exact probability test and χ2 test were used to compare the incidences of infection and graft rupture, respectively. We included 20 randomized controlled trials involving 1,515 patients. The AMP technique showed a lower side-to-side difference (standardized mean difference, -0.33; 95% credible interval [CrI], -0.53 to -0.12), higher negative rate on the pivot-shift test (odds ratio, 2.19; 95% CrI, 1.38 to 3.44), and higher International Knee Documentation Committee objective score (odds ratio, 3.13; 95% CrI, 1.42 to 7.82) than the sTT technique. However, knee stability and functional outcomes did not differ significantly between the OI and sTT techniques. Safety outcomes of the mTT technique were unavailable. The incidence of graft rupture was 5.20% for the OI technique, 2.27% for the AMP technique, and 1.51% for the sTT technique. The OI technique had a significantly higher incidence of graft rupture than the sTT technique (χ2= 4.421, P= .035). No significant difference in the incidence of infection was found between the sTT, AMP, and OI techniques (P= .281). The AMP technique, but not the OI technique, was superior to the sTT technique in knee stability and functional recovery. The OI technique had a higher incidence of graft rupture than the sTT technique. There was no significant difference between the AMP and OI techniques or between the mTT technique and any other femoral drilling technique. Level II, meta-analysis of Level I and II studies.

Risk Factors for Revision or Rerupture After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis.

The rerupture or need for revision after anterior cruciate ligament reconstruction (ACLR) is a serious complication. Preventive strategies that target the early identification of risk factors are important to reduce the incidence of additional surgery. To perform a systematic review and meta-analysis to investigate risk factors for revision or rerupture after ACLR. Systematic review and meta-analysis; Level of evidence, 4. Literature searches were performed in PubMed, Embase, and Web of Science from database inception to November 2021 and updated in January 2022. Quantitative, original studies reporting potential adjusted risk factors were included. Odds ratios (ORs) were calculated for potential risk factors. A total of 71 studies across 13 countries with a total sample size of 629,120 met the inclusion criteria. Fifteen factors were associated with an increase in the risk of revision or rerupture after ACLR: male sex (OR, 1.27; 95% CI, 1.14-1.41), younger age (OR, 1.07; 95% CI, 1.05-1.08), lower body mass index (BMI) (OR, 1.03; 95% CI, 1.00-1.06), family history (OR, 2.47; 95% CI, 1.50-4.08), White race (OR, 1.32; 95% CI, 1.08-1.60), higher posterolateral tibial slope (OR, 1.15; 95% CI, 1.05-1.26), preoperative high-grade anterior knee laxity (OR, 2.30; 95% CI, 1.46-3.64), higher baseline Marx activity level (OR, 1.07; 95% CI, 1.02-1.13), return to a high activity level/sport (OR, 2.03; 95% CI, 1.15-3.57), an ACLR within less than a year after injury (OR, 2.05; 95% CI, 1.81-2.32), a concomitant medial collateral ligament (MCL) injury (OR, 1.62; 95% CI, 1.31-2.00), an anteromedial portal or transportal technique (OR, 1.36; 95% CI, 1.22-1.51), hamstring tendon (HT) autografts (vs bone-patellar tendon-bone [BPTB] autografts) (OR, 1.60; 95% CI, 1.40-1.82), allografts (OR, 2.63; 95% CI, 1.65-4.19), and smaller graft diameter (OR, 1.21; 95% CI, 1.05-1.38). The other factors failed to show an association with an increased risk of revision or rerupture after ACLR. Male sex, younger age, lower BMI, family history, White race, higher posterolateral tibial slope, preoperative high-grade anterior knee laxity, higher baseline Marx activity level, return to a high activity level/sport, an ACLR within less than a year from injury, a concomitant MCL injury, an anteromedial portal or transportal technique, HT autografts (vs BPTB autografts), allografts, and smaller graft diameter may increase the risk of revision or rerupture after ACLR. Raising awareness and implementing effective preventions/interventions for risk factors are priorities for clinical practitioners to reduce the incidence of revision or rerupture after ACLR.

MRI signal intensity of anterior cruciate ligament graft after transtibial versus anteromedial portal technique (TRANSIG): A randomised controlled clinical trial

BackgroundTwo primary surgical femoral drilling techniques are used to reconstruct the anterior cruciate ligament (ACL): the transtibial (TT) technique and the anteromedial portal (AMP) technique. Currently there is no consensus on which surgical technique elicits the best clinical and functional outcomes. MRI-derived measures of the signal intensity (SI) of the ACL graft have been described as an independent predictor of graft properties. The purpose of this study was to assess MRI-derived SI measurements of the ACL graft one year after ACL reconstruction, in order to compare graft maturation of both AMP and TT ACL reconstruction techniques. MethodsThis randomised controlled trial included 33 patients admitted for primary unilateral ACL reconstruction. Primary outcome was MRI Signal intensity ratio (SIR) of the ACL graft one year after ACL reconstruction. Differences in MRI SIR were assessed on two MRI sequencies: sagittal Proton Density Turbo Spin Echo weighted images (PDTSE) and 3D T2 Gradient Echo (T2*) weighted images. Analysis of interobserver and intraobserver variability was conducted for the SIR measurements. ResultsNo difference in signal intensity of the graft was found between the TT and AMP techniques one year after ACL reconstruction (PDTSE p = 0.665, T2* p = 0.957). Both interobserver and intraobserver variability showed strong agreement (ICC 0.64–0.94). ConclusionNo differences in signal intensity of the graft on MRI were seen between the femoral drilling techniques one year after ACL reconstruction, suggesting similar graft maturation at that time. Follow-up studies are needed to determine whether graft intensity changes in the long term. Level of evidenceTherapeutic study with level of evidence I.

The Hybrid Transtibial Technique for Femoral Tunnel Drilling in Anterior Cruciate Ligament Reconstruction: A Finite Element Analysis Model of Graft Bending Angles and Peak Graft Stresses in Comparison With Transtibial and Anteromedial Portal Techniques.

The purpose of this finite element analysis was to compare femoral tunnel length; anterior cruciate ligament reconstruction graft bending angle; and peak graft stress, contact force, and contact area created by the transtibial, anteromedial portal (AMP), and hybrid transtibial techniques. Finite element analysis modeling was used to examine anterior cruciate ligament reconstruction models based on transtibial, AMP, and hybrid transtibial femoral tunnel drilling techniques. An evaluation of femoral tunnel length, graft bending angle, peak graft stress, contact force, and contact area was done in comparison of these techniques. The femoral tunnel created with the hybrid transtibial technique was 45.3 mm, which was 13.3% longer than that achieved with the AMP technique but 15.2% shorter than that with the transtibial technique. The femoral graft bending angle with the hybrid transtibial technique (105°) was less acute than that with the AMP technique (102°), but more acute than that with the transtibial technique (109°). At 11° knee flexion, the hybrid transtibial technique had 22% less femoral contact force, 21% less tibial contact force, 21% less graft tension than the AMP technique. Yet, the hybrid transtibial technique had 41% greater femoral contact force, 39% greater tibial contact force, 33% greater graft tension, and 6% greater graft von Mises stress than the transtibial technique. A similar trend was found for the anterior knee drawer test. At both 6-mm anterior tibial displacement and 11° knee flexion, the hybrid transtibial and AMP techniques had at least 51% more femoral contact area than the transtibial technique. This finite element analysis highlights that the hybrid transtibial technique is a true hybrid between the AMP and transtibial techniques for femoral tunnel drilling regarding femoral tunnel length, graft bending angle, and peak graft stress.

Anteromedial Portal versus Transtibial Drilling Techniques for Femoral Tunnel Placement in Arthroscopic Anterior Cruciate Ligament Reconstruction: Radiographic Evaluation and Functional Outcomes at 2 Years Follow-Up.

The aim of this study was to compare the functional and radiographic outcomes of arthroscopic single-bundle anterior cruciate ligament reconstruction (ACLR) using either the anteromedial (AM) portal technique or transtibial (TT) technique. We identified 404 patients who underwent arthroscopic ACLR by a single surgeon between January 2006 and December 2016 at our institution. The TT portal was utilized in femoral tunnel drilling in 202 patients (TT group) while the AM portal was used in 202 patients (AM group). The mean postoperative follow-up duration was 26 months (range: 24-33 months). Postoperative radiographic femoral and tibial tunnel positions were assessed by two independent observers. Functional outcomes were evaluated with Tegner, Lysholm, and Knee Injury and Osteoarthritis Outcome score (KOOS) scores. On the anteroposterior plain radiographs, the mean femoral tunnel position relative to the lateral femoral condyle was 46.8% for the AM group versus 48.6% in the TT group, respectively (p=0.003). The mean graft inclination angle was 31.9° and 22° in the AM and TT groups, respectively (p<0.0001). On the lateral radiographs, the mean femoral tunnel placement across Blumensaat's line in relation to the anterior femoral cortex was 84% in the AM group while it was 78% in the TT group (p<0.0001). At 2 years postoperatively, there were no significant differences in the mean Tegner, Lysholm, and KOOS scores between the two patient groups. The graft failure rate at 2 years follow-up was 4.5% (n=9) in the AM group while it was 2.5% (n=5) in the TT group (p=0.2). Femoral tunnel placement was more anatomical with the AM portal technique compared with the TT technique. However, there was no significant difference in postoperative functional outcomes between the two patient groups. The AM portal technique appears to have a higher graft failure rate. This might be attributed to increased graft loading in an anatomical position.

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

BackgroundAnterior Cruciate Ligament (ACL) injuries are common in the active population of the Armed Forces. Symptomatic instability prompts individuals to seek a cure or a sheltered appointment. Despite the increasing numbers of ACL reconstructions performed, the outcomes have not been so spectacular with only a meager percentage of our patients returning to preinjury levels of activity. With the premise that an all-inside ACL reconstruction is likely to result in better functional outcomes, the aim of this study was to compare the short-term functional outcomes of a large consecutive series of patients undergoing ACL reconstruction using the translateral all-inside ACL reconstruction technique (AI) and standard anteromedial portal technique (AM) with a minimum follow-up of one year. MethodsA total of 240 patients with isolated ACL tear underwent ACL reconstruction via the AI or AM technique. Their preoperative and postoperative scores were compared to look for any significant differences in functional outcomes. ResultsThe two groups were matched for age, BMI, mechanism of injury, and interval from injury to surgery. There was no difference in their preoperative scores. Postoperatively, although there were significant improvements across both groups, there was no significant difference between the groups at any point of time. ConclusionThe AI technique has garnered interest in recent literature in addressing ACL injuries. This study found no discernible benefit of the AI technique when compared to the AM technique in terms of functionality following an ACL reconstruction at any point of time up to 1 year following surgery.

Poster 255: Lateral Extra-Articular Tenodesis Staple Risks Penetration of ACL Reconstruction Tunnel

Objectives:The purpose of this study was to identify the risk of ACL femoral tunnel penetration by a small Richards staple used for Lateral Extra-Articular Tenodesis (LET) fixation and to determine whether or not the risk varies between two techniques for ACL femoral tunnel creation.Methods:20 paired fresh frozen cadaver knees underwent ACL reconstruction with a LET using the modified Lemaire technique (Getgood et al. AJSM, Jan 2020). Left and right knees were randomized to ACL reconstruction with femoral tunnel creation by either the accessory anteromedial portal (AMP) technique or the flexible guide pin and reamer method. The femoral tunnels in the accessory AMP technique arm were created using a 7mm offset guide. Both arms used a 10mm reamer and were reamed to a depth of 25mm. After tunnel creation and prior to passing the ACL graft, the LET was performed. This was completed by harvesting an 8cm long and 10mm wide central portion of the IT band which was left attached to its distal insertion on Gerdy’s tubercle. This was routed underneath the LCL and fixed with a small Richards staple on the lateral metaphyseal flare proximal and posterior to the LCL insertion. The staple was angled anteriorly and distally. Fluoroscopy was used to obtain a lateral view of the knee to ensure appropriate position of the staple (Figure 1). Finally, tunneloscopy was performed from the anteromedial portal to investigate penetration of the staple into the femoral tunnel (Figure 2). A Fisher’s exact test was conducted to determine if there was any difference in tunnel penetration between tunnel creation techniques.Results:The staple was noted to penetrate the ACL femoral tunnel in 8/20 (40%) extremities. When stratified by tunnel creation technique, the Richards staple violated 5/10 (50%) of the tunnels made via the accessory AMP technique compared to 3/10 (30%) of those created with a flexible guide pin and reamer (p = 0.65).Conclusions:Staple fixation of a LET carries significant risk of penetrating the ACL tunnel that does not vary by the technique of femoral tunnel creation. This raises concerns over the potential effect of the staple on ACL graft fixation and the ACL graft itself.

Poster 256: The "N+10 Rule" to Avoid Graft Tunnel Mismatch in Bone-Patellar Tendon-Bone Anterior Cruciate Ligament Reconstruction Using Independent Femoral Tunnel Drilling

Objectives: To determine the amount of tibial graft tunnel mismatch during application of the “N+10” rule in arthroscopic assisted anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BTB) graft using independent femoral tunnel drilling.To compare actual (measured) tibial tunnel length and desired (calculated) tibial tunnel length when using the “N+10” rule for independent femoral tunnel drilling. Methods:Twenty paired knees from 10 fresh frozen cadaveric specimens (5 female and 5 male specimens) underwent arthroscopic assisted bone-patellar tendon-bone ACL reconstruction using independent femoral tunnel drilling with either a hyperflexion accessory anteromedial portal (n=10) or flexible reamer technique (n=10). The prepared patellar tendon graft bone blocks were trimmed to 10 x 20mm for all specimens and the intertendinous distance (N) between the bone blocks was measured. The “N+10 Rule” was used to set the angle of the ACL tibial tunnel guide to the appropriate degree setting for drilling. The amount of excursion or recession of the tibial bone plug in relation to the anterior tibial cortical aperture was measured in both flexion and extension. A +/-6mm threshold was used to assess this strategy based on prior biomechanical aperture fixation studies. As a secondary outcome, the intraarticular distance (IAD) and the actual tibial tunnel length (TTL) were measured and compared to the planned TTL based on the equation: IAD + TTL = N + 20 (size of bone plug in millimeters)Results:The average BTB ACL intertendinous distance (N) was 47.5mm (SD =5.5mm). The average measured IAD was 27.2mm (SD=3.0mm). Using the “N+10 Rule”, the average mismatch of the tibial tunnel was 4.9mm (SD=3.6mm) and 3.8mm (SD=3.5mm) in flexion and extension, respectively. Both values fall within the +/- 6mm threshold. When comparing the actual measured tibial tunnel length (TTL) to the desired TTL, there was an average difference of 5.4mm (SD=3.9mm)Conclusions:The “N+10” rule resulted in an acceptable average mismatch in both flexion and extension using the threshold of +/- 6mm for 20 cadaveric knees. Measured actual TTL compared to the desired calculated TTL were acceptable 61% of the time using the same threshold. The “N+10” is a simple and effective intraoperative strategy for achieving desired tibial tunnel length to avoid excessive graft tunnel mismatch.Figure 1:Derived formula for calculating ideal tibial tunnel length (TTL) using intraarticular distance (IAD), and the known values of the intertendinous distance (N) and lengths of the bone blocks (20mm).Figure 2:Intraoperative photo of BTB ACL graft measuring intertendinous distance between the bone plugs (N=55mm). Following the "N+10" ruleFigure 3:Intraoperative photo of tibial ACL guide measurement of tibial tunnel length at 50mm with guide set to 65 degrees.Figure 4:Intraoperative photo of the ACL tibial tunnel guide positioned on the anatomic tibial footprint set to 65 degrees (N=55mm). Using this setting for the guide, the tibial tunnel measured 50mm as seen in the zoomed in photo, as per the formula.

Influence of the Anteromedial Portal and Transtibial Drilling Technique on Femoral Tunnel Lengths in ACL Reconstruction: Results Using an MRI-Based Model.

Background:In anatomic anterior cruciate ligament (ACL) reconstruction, graft placement through the anteromedial (AM) portal technique requires more horizontal drilling of the femoral tunnel as compared with the transtibial (TT) technique, which may lead to a shorter femoral tunnel and affect graft-to-bone healing. The effect of coronal and sagittal femoral tunnel obliquity angle on femoral tunnel length has not been investigated.Purpose:To compare the length of the femoral tunnels created with the TT technique versus the AM portal technique at different coronal and sagittal obliquity angles using the native femoral ACL center as the starting point of the femoral tunnel. The authors also assessed sex-based differences in tunnel lengths.Study Design:Descriptive laboratory study.Methods:Magnetic resonance imaging scans of 95 knees with an ACL rupture (55 men, 40 women; mean age, 26 years [range, 16-45 years]) were used to create 3-dimensional models of the femur. The femoral tunnel was simulated on each model using the TT and AM portal techniques; for the latter, several coronal and sagittal obliquity angles were simulated (coronal, 30°, 45°, and 60°; sagittal, 45° and 60°), representing the 10:00, 10:30, and 11:00 clockface positions for the right knee. The length of the femoral tunnel was compared between the techniques and between male and female patients.Results:The mean ± SD femoral tunnel length with the TT technique was 40.0 ± 6.8 mm. A significantly shorter tunnel was created with the AM portal technique at 30° coronal/45° sagittal (35.5 ± 3.8 mm), whereas a longer tunnel was created at 60° coronal/60° sagittal (53.3 ± 5.3 mm; P < .05 for both). The femoral tunnel created with the AM portal technique at 45° coronal/45° sagittal (40.7 ± 4.8 mm) created a similar tunnel length as the TT technique. For all techniques, the femoral tunnel was significantly shorter in female patients than male patients.Conclusion:The coronal and sagittal obliquity angles of the femoral tunnel in ACL reconstruction can significantly affect its length. The femoral tunnel created with the AM portal technique at 45° coronal/45° sagittal was similar to that created with the TT technique.Clinical Relevance:Surgeons should be aware of the femoral tunnel shortening with lower coronal obliquity angles, especially in female patients.

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction

AimTo analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique. MethodsFrom January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability. ResultsGroup B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups. ConclusionACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.