In combined anterior cruciate ligament reconstruction (ACLR) and anterolateral ligament reconstruction (ALLR) using hamstring autografts, a femoral in-tunnel graft length (FTGL) of at least 15 mm has traditionally been recommended. However, achieving this length is not always feasible. To evaluate graft healing and clinical outcomes in patients with an intraoperative FTGL target of 10 to 15 mm, and to investigate whether shorter postoperative magnetic resonance imaging (MRI)-measured FTGL (mFTGL) within this cohort affected outcomes through subgroup analysis. Case series; Level of evidence: 4Methods:The records of patients who underwent primary single-bundle ACLR using a quadrupled semitendinosus autograft and ALLR using a gracilis autograft, with a minimum 2-year follow-up, were retrospectively reviewed. During surgery, the FTGL was intentionally set to fall within the 10- to 15-mm range. Postoperatively, the graft length within the femoral tunnel was measured on postoperative day 2 MRI (mFTGL) and used for analyses. Graft healing was evaluated using 6-month MRI scans: (1) graft incorporation, assessed by the signal-to-noise quotient (SNQ) at the tunnel (SNQ_tunnel), signal intensity at the graft-bone interface, and tunnel widening; and (2) graft ligamentization, assessed by the SNQ of the graft (SNQ_graft) and Howell grade. Clinical outcomes were also assessed. For subgroup analysis, patients were classified into group 1 (mFTGL ≤12.6 mm) and group 2 (mFTGL >12.6 mm). A total of 180 knees were consecutively enrolled; 169 completed the 6-month MRI evaluation. The graft failure rate was 3.9%. The mean mFTGL was 12.6 ± 2.6 mm. In subgroup analysis, the femoral SNQ_tunnel difference between the tunnel aperture and proximal site was 0.9 ± 3.3 for group 1 and 2.3 ± 3.9 for group 2 (P = .014). Femoral tunnel widening was 60.1% ± 30.7% for group 1 and 74.3% ± 37.2% for group 2 (P = .008). In multiple regression analysis, mFTGL (β = 3.28; P < .001) and graft diameter (β = -23.86; P < .001) were independently associated with femoral tunnel widening. In combined ACLR and ALLR, an intraoperative FTGL target of 10 to 15 mm was clinically acceptable regarding graft failure, graft healing, and clinical outcomes. The subgroup with shorter FTGL showed less femoral tunnel widening.

This study aimed to determine whether patient-specific 3D-printed guide plates enhance femoral tunnel placement accuracy, reduce operative time, and promote faster functional and kinematic recovery in medial patellofemoral ligament (MPFL) reconstruction compared to conventional techniques. Prospective, randomized controlled trial. Single academic tertiary care hospital. Sixty patients diagnosed with recurrent patellar dislocation were enrolled and randomly assigned to either a 3D-printed guide plate group (n = 30) or a conventional fluoroscopy-guided group (n = 30). Patients in the intervention group underwent MPFL reconstruction assisted by customized 3D-printed guide plates for femoral tunnel placement. The control group received conventional fluoroscopy-assisted MPFL reconstruction. Both groups followed an identical rehabilitation protocol postoperatively. Primary outcomes included operative time, femoral tunnel placement accuracy (distance from the Schöttle point), knee function scores (Lysholm, Kujala, Tegner, IKDC), and 3D gait kinematics using the Opti-Knee system. Knee function scores were assessed preoperatively at 3, 6, and 12 months, and 3D gait kinematics were tested preoperatively at 3, 6, 9, and 12 months. The 3D-printed group had significantly shorter operative times (68 ± 12 min) than the conventional group (85 ± 16 min; p < 0.05). Femoral tunnel deviation was lower in the 3D group (5.42 ± 2.29 mm) compared to controls (7.65 ± 2.47 mm; p < 0.001). Functional scores were higher in the 3D group at 3 and 6 months (p < 0.05), and flexion-extension kinematics normalized by 6 months in the 3D group compared to 12 months in controls. 3D-printed guide plates improve femoral tunnel accuracy and reduce surgical time, accelerating early functional recovery. These findings support their clinical utility as a superior alternative to conventional guidance methods.

Introduction: Medial Patellofemoral Ligament (MPFL) reconstruction is the standard of care for recurrent patellar dislocation. However, clinical success is heavily contingent upon precise femoral tunnel placement. Malpositioning can compromise ligament isometry and lead to poor postoperative outcomes. This study evaluates the correlation between anatomical tunnel accuracy and clinical recovery, underscoring the importance of meticulous surgical technique. Materials and Methods: We retrospectively analyzed 124 patients (124 knees) treated for recurrent patellar dislocation between January 2021 and December 2024. The cohort comprised 31 males and 93 females (mean age 15.4 years). Inclusion criteria included a positive apprehension test, J-sign, and lateral patellar tilt. Postoperative outcomes were assessed using the Lysholm Knee Score. CT and MRI were used to measure the distance from the center of the femoral tunnel to the anatomical isometric point, classifying the positions as isometric or non-isometric. Results: At a mean follow-up of 18 months, no recurrent dislocations occurred. The mean Lysholm score was 93.8. The average deviation from the isometric point was 4.51 mm; 86 cases (69.4%) were classified as isometric, while 38 (30.6%) were non-isometric. A strong negative correlation was observed between tunnel deviation and Lysholm scores (r = -0.851, P &lt; 0.001). The isometric group demonstrated significantly higher functional scores (95.4 ± 2.2) than the non-isometric group (88.4 ± 3.3; P &lt; 0.001). Furthermore, 58% of the non-isometric group experienced persistent retro-patellar pain, with two patients requiring revision arthroscopy. Conclusion: Anatomical and isometric restoration of the femoral tunnel is critical for optimal knee function recovery in MPFL reconstruction. Meticulous surgical technique is vital to minimize complications such as residual pain and ensure favorable long-term outcomes.

There are multiple techniques for femoral tunnel creation for anterior cruciate ligament (ACL) reconstruction, with most modern techniques revolving around retrograde drilling or anteromedial (AM) portal drilling. To compile and quantify patient-reported outcomes and complication rates in patients who undergo hamstring ACL reconstruction with femoral tunnel creation via AM portal drilling versus retrograde drilling techniques. Systematic review and meta-analysis; Level of evidence, 1. In accordance with PRISMA guidelines, PubMed, Embase, and Cochrane Library databases were searched in August 2024 for studies published after 2004. Studies were included if they (1) were level 1 randomized controlled trials, (2) comprised patients who underwent primary ACL reconstruction utilizing hamstring tendon autograft, and (3) compared femoral tunnels created via AM portal antegrade drilling versus retrograde drilling techniques. Studies that were not written in English or did not directly compare patients being treated with either femoral tunnel technique were excluded. Data were pooled with a DerSimonian-Laird random effects model, and risk of bias was assessed with the Cochrane RoB 2 tool. The initial search identified 1003 studies, of which 5 randomized controlled trials were included in this study with a total of 557 patients: 280 in the AM portal cohort and 277 in the retrograde drilling cohort. Mean ages across the cohorts ranged from 26.4 to 34.2 years. All patients had a minimum 6 months of follow-up. Descriptive data were similar between graft cohorts, and studies had low risk of bias and low heterogeneity. The mean difference in International Knee Documentation Committee score for the retrograde drilling versus AM portal cohorts was 1.0 (95% CI, -0.3 to 2.3). The odds ratios (ORs) for retrograde drilling versus AM portal showed no significant differences for revision ACL (OR, 2.1; 95% CI, -0.5 to 8.9), overall reoperation (OR, 1.1; 95% CI, 0.5-2.4), and total complications (OR, 1.0; 95% CI, 0.5-2.0). Primary ACL reconstruction has no significant differences in patient-reported outcomes, complications, or revision ACL rates when femoral tunnels are created via AM portal antegrade drilling versus retrograde drilling techniques. Decisions regarding ACL reconstruction technique should be tailored to individual patient needs and surgeon preference.

Objective: To quantitatively evaluate the efficacy, precision, and reproducibility of the surgical navigation module of a novel robotic-assisted anterior cruciate ligament reconstruction (ACLR) system during bone tunnel drilling using in vitro models. Methods: Thirty 3D-printed knee models were randomized into a robotic group (n=15) and a conventional group (n=15) using a random number table. Both groups utilized the same individualized surgical plans generated by the system's preoperative planning module. In the robotic group, bone tunnel drilling was guided by the system's mechanical arm; in the conventional group, drilling was performed manually by senior sports medicine surgeons using traditional instrumentation. Operative time was recorded. Postoperative bone tunnel lengths and tunnel exit positions in both groups were compared with the preoperative planning values among the three groups. Results: The total operative time was significantly longer in the robotic group [(25.83±2.20) vs (15.55±1.96) min, P<0.001], whereas the robotic group achieved a significantly shorter duration for the core bone tunnel drilling phase [6.08 (5.72, 6.75) vs 7.60 (6.80, 8.52) min, P=0.003]. There were no statistically significant differences among the three groups regarding the numerical values of the three length indicators (femoral and tibial tunnel lengths, intra-articular distance) or the four tunnel exit position dimensions (deep-shallow, high-low, anterior-posterior, medial-lateral) within the Bernard quadrant (all P>0.05). However, the variance in all positioning dimensions was significantly lower in the robotic group compared to the conventional group (all P<0.05), particularly in the femoral high-low and tibial anterior-posterior directions (both P<0.001), indicating superior consistency in robot-assisted operation. Conclusions: Robot-assisted ACLR technology improves efficiency during the critical drilling phase and significantly minimizes manual operational variability. These findings provide experimental evidence supporting the application of high-precision surgical navigation in ACLR.

Two-incision anterior cruciate ligament reconstruction (ACLR) is a well-established technique used to perform an arthroscopically assisted ACLR. Historically, this approach to ACLR was once considered the benchmark; however, with evolving arthroscopic technology and the rise of more minimally invasive techniques, this approach to ACLR has become less popular. The two-incision technique still has notable clinical utility because it can (1) increase the surgeon's ability to perform a single-stage revision ACLR and (2) help avoid graft-tunnel mismatch in primary ACLR with a patellar tendon autograft when encountering a long tendon. This technique, when coupled with metal screws and an autograft tendon, is also the lowest cost ACLR technique that allows independent femoral tunnel positioning and thus should be considered as an option for primary ACLR by surgeons prioritizing cost containment without compromising surgical outcomes.

Variations in graft maturity between quadriceps tendon and semitendinosus tendon at 6 months after anterior cruciate ligament reconstruction: A quantitative assessment using UTE-T2* mapping.

Background/Objectives: Variations in drill orientation during femoral and tibial tunnel creation can alter intra-articular tunnel aperture morphology in anterior cruciate ligament (ACL) reconstruction. Enlarged or irregular apertures may affect graft-tunnel conformity and graft mechanics. This study aimed to assess the relationship between intra-articular femoral and tibial tunnel aperture areas, postoperative clinical outcomes, and graft rerupture. This study specifically focuses on MRI-based measurement of intra-articular tunnel aperture area, a morphological parameter that has not been routinely evaluated in previous ACL reconstruction studies and differs conceptually from tunnel diameter or drilling angles. Methods: This retrospective case-control study included patients who underwent primary ACL reconstruction with an 8 mm hamstring autograft using the anteromedial portal technique. All patients completed a minimum 2-year follow-up and postoperative MRI. Femoral and tibial intra-articular aperture areas were measured on MRI Clinical outcomes (Lysholm scores and KOOSs) in patients with intact grafts. Patients were categorized into intact-graft and rerupture groups. Correlation analyses were used to evaluate associations between aperture areas and clinical outcomes. Logistic regression identified predictors of rerupture. Results: A total of 152 patients met the inclusion criteria, including 13 with graft rerupture. In the intact-graft group, mean femoral and tibial aperture areas were 127.34 ± 8.92 mm2 and 138.33 ± 7.08 mm2, respectively. Both aperture areas demonstrated significant negative correlations with Lysholm scores and KOOSs. Patients with rerupture had significantly larger femoral (145.26 ± 4.22 mm2) and tibial (158.02 ± 2.88 mm2) aperture areas (p < 0.001 for both). Logistic regression identified tibial aperture area as a significant predictor of rerupture. Conclusions: Larger intra-articular tunnel aperture areas were associated with inferior functional outcomes, and increased tibial aperture area correlated significantly with graft rerupture. Aperture morphology may represent an important factor influencing graft integrity and postoperative recovery after ACL reconstruction.

Background:Recent studies have used the anterior cruciate ligament reconstruction (ACLR) mouse model to study the tendon-bone healing process. Although mechanical load has an important effect on ACL graft healing, only a limited number of studies have investigated the effect of treadmill exercise.Purpose/Hypothesis:This study aimed to investigate the effects of different mechanical loading stimuli on the tendon-bone interface (TBI) healing process after ACLR in mice. It was hypothesized that moderate loading would positively affect TBI healing after ACLR.Study Design:Controlled laboratory study.Methods:A total of 58 C57BL/6 male mice (12 weeks old) underwent ACLR of the right knee. The first 30 mice were assigned to 5 exercise groups (n = 6 per group) to evaluate the different exercise regimens (study arm 1). After the optimal exercise regimen was identified, an additional 28 mice were included, and 14 mice in the exercise regimen were compared with 14 free cage controls (study arm 2). Starting 7 days after surgery, treadmill exercise was performed 5 days per week for 3 weeks. All animals were euthanized 4 weeks after surgery. Microfocus computed tomography (μCT) imaging, biomechanical testing, and histological tendon–bone tunnel healing (TBTH) scoring were performed. Statistical analyses were performed using the Wilcoxon signed rank test, the Mann-Whitney U test, and 1-way analysis of variance with a post hoc Tukey honestly significant difference test. Statistical significance was defined as P < .05.Results:In study arm 1, no significant intergroup differences were observed in the μCT analysis (P = .18-.72) and histological assessment (P = .21). For study arm 2, the 10-m/min, 50-minute treadmill exercise was selected. Further μCT and biomechanical testing in study arm 2 revealed no significant intergroup differences. However, histological evaluation revealed significantly higher TBTH scores in the treadmill group as compared with the free cage activity group. This difference was most pronounced in the extra-articular region of the femoral tunnel (mean ± SD, 4.28 ± 2.15 vs 8.18 ± 2.98; P = .027) and the intra-articular region of the tibial tunnel (7.17 ± 7.07 vs 16.62 ± 5.42; P = .027).Conclusion:Our study demonstrated that moderate treadmill exercise after ACLR positively affects TBI healing in the femoral and tibial tunnels in the murine model. Future studies are necessary to objectively quantify the optimal type, magnitude, and duration of loading.Clinical Relevance:There may be a role for a moderate-load rehabilitation protocol to improve healing of the tendon graft–bone interface in patients after ACLR.

The goals of this study were to develop an artificial intelligence (AI)-driven automated preoperative planning system for anterior cruciate ligament (ACL) reconstruction by integrating deep learning with computed tomography (CT)-magnetic resonance imaging (MRI) image fusion and segmentation, and to evaluate its accuracy. Structures on CT and MRI scans of 200 knee joints from patients with an intact ACL (aged 18 to 50 years, 81.0% male, all ethnic Chinese) were manually annotated. Fusion of the CT and MRI images was performed using a Dual-UNet registration architecture incorporating multiscale information fusion, enabling dynamic 3D reconstruction of the fused images for ACL insertion site identification and isometry assessment. A deep-learning framework was trained to analyze the fused image to precisely optimize ACL tunnel positioning, including identifying the entrances and exits of the femoral and tibial tunnels. Criteria in the automated planning included proximity to the ideal point, coverage of the anatomical footprint area, and isometric length variation of <2 mm. The accuracy of the AI system was then validated in 36 ACL reconstructions performed in bone models by comparing the drilled femoral and tibial tunnel lengths and graft length between the tunnels with the planned values. Finally, clinical feasibility was tested in 36 patients undergoing ACL reconstruction surgery using 3D-printed patient-specific guides derived from the AI planning, with 36 conventional surgeries as controls. Deviation of tunnel positions from the planned positions was compared between the 2 groups. CT-MRI image fusion was able to generate an individualized 3D model with high segmentation accuracy (Dice coefficient = 0.864). The AI planning required 192 ± 90.2 seconds per case. In the bone model validation, the mean deviation between the planned and executed values was <1 mm for the femoral and tibial tunnel lengths and graft length between the tunnels (all p > 0.05). In the clinical testing, the AI-guided group demonstrated significantly smaller deviations from the ideal point compared with the conventional group in the deep-to-shallow (D-S), high-to-low (H-L), medial-to-lateral (M-L), and anterior-to-posterior (A-P) directions (all p < 0.05). The AI-driven segmentation of CT-MRI fusion images and automatic preoperative ACL reconstruction planning demonstrated the capability to automatically, precisely, and reproducibly generate plans for nearly ideal tunnel entry and exit points with isometric, anatomical, and individualization characteristics. This technology is expected to hold clinical potential for ACL reconstruction, including reduced complication and revision rates and enhanced postoperative function.

This report describes the case of a woman in her 40s who developed debilitating knee pain and instability 1 year after undergoing an anterior cruciate ligament reconstruction. MRI revealed a complex pathology, including marked widening of both the femoral and tibial bone tunnels, significant perigraft cyst formation, a complete posterior root tear of the medial meniscus with extrusion and a partial tear of the lateral meniscal root. This indicated a functional failure of the primary reconstruction, leading to secondary intra-articular damage. A staged surgical approach was planned with an open excision of the proximal tibial tunnel cyst with meticulous curettage of the tunnel walls, combined with an arthroscopic all-inside repair of the medial meniscus. Substantial bone loss was addressed with autologous iliac crest bone graft. The patient experienced an uneventful recovery with significant symptomatic improvement, evidence-based approach to managing complex postoperative anterior cruciate ligament reconstruction complications.

Etiology and effects of cyclops lesions in double-bundle anterior cruciate ligament reconstruction: A case-control study.

Anatomical reconstruction of the posterior cruciate ligament (PCL) with suture tape augmentation to enhance primary stability. Acute or chronic PCL ruptures, either isolated or as part of multiligamentous injuries, in cases of symptomatic instability or failure of conservative treatment. Fixed posterior drawer, active infection, bony avulsion. Supine positioning, use of standard portals for arthroscopic PCL reconstruction. Femoral and tibial tunnels are created using atargeting device following preparation of the insertion sites. The hamstring graft is augmented with nonresorbable suture tape. The augmentation suture is fixed separately using asuture anchor under continuous anterior drawer stress. Graft fixation is performed via extracortical device at the femur and with an interference screw at the tibia. Six weeks of extension bracing with posterior tibial support, worn 24 h/day, and 20 kg partial weight-bearing. This is followed by 6weeks of continued mobile bracing with posterior tibial support and progressive mobilization and load increase, accompanied by physiotherapy. Biomechanical and early clinical studies suggest promising benefits of augmentation for stability and function, though robust long-term data are still lacking.

Surgical efficacy in paediatric anterior cruciate ligament reconstruction: A comparative 3-case study of actual and simulated surgeries.

25-Year trends in anterior cruciate ligament reconstruction: Results from the biennial ACL Study Group survey from 1998 to 2023.

The rate of recurrent instability following primary medial patellofemoral ligament (MPFL) reconstruction has been reported to be as high as 6.7%. However, limited studies have reported on clinical outcomes and complications following revision MPFL reconstruction. Furthermore, the role of previously identified risk factors for primary failure (e.g., patella alta and trochlear dysplasia) warrants further study in this patient population. Therefore, the goal of this study was 2-fold. First, to evaluate the prevalence of anatomic risk factors and technical errors among patients presenting for revision patellofemoral surgery. Second, to report early clinical outcomes following revision MPFL reconstruction. A single-surgeon registry was queried for patients who underwent revision MPFL reconstruction (including prior MPFL imbrication, MPFL reconstruction, tibial tubercle osteotomy [TTO]) from November 2015 to June 2022. Preoperative imaging was evaluated for risk factors including (1) misplacement of the femoral tunnel, (2) Caton-Deschamps index, (3) tibial tubercle-trochlear groove distance (TT-TG), (4) patellar tilt, and (5) trochlear dysplasia. Patient-reported outcomes and complications were obtained at final follow-up (minimum 1 year). The study included 32 patients (72% female, age: 23.9 ± 6.6 years). Mean time from index surgery to revision MPFL reconstruction was 4.8 ± 4.7 years (range 0.6 to 17.9 years). The most prevalent anatomic risk factors were patella alta (72%), TT-TG >15 mm (53%), trochlear dysplasia (Dejour type B, C, or D) (50%), and excessive patellar tilt (41%). The median number of risk factors was 3 (range 0-6), and 17 patients (53%) had three or more risk factors. At final follow-up (24.1 ± 14.5 months), no patients experienced recurrent patellofemoral instability or graft failure. Postoperative IKDC (p < 0.001) and SF-12 PCS (p < 0.001) scores improved significantly compared with preoperatively. In conclusion, the majority of patients presenting for revision MPFL reconstruction had three or more risk factors for recurrent dislocation.IV, Case Series.

The purpose of this study was to compare the all-inside (Group A) and conventional (Group B) anterior cruciate ligament reconstruction (ACLR) methods in terms of tunnel or socket morphology and functional outcomes. Retrospective cohort study. Tunnel morphology was evaluated using a computed tomography scan and compared with intra-operative tibial and femoral drilling diameter at a mean follow-up of 29months following ACLR between these groups. Clinical outcomes were studied using the 2000 IKDC subjective knee score, Lysholm score, and Knee Laxity Tester. The study compared the tunnel morphology of all-inside (Group A; 20 subjects) and conventional (Group B; 43 subjects) ACLR methods in 63 patients. The results showed no significant differences in functional outcomes between the two groups. However, the femoral tunnel shrunk in Group A by 1.32% and 6.9% at articular (F1) and mid-portion (F2), respectively, compared to Group B at the same locations. The tibial tunnel widened in Group A by 1.91% and 11.07% at articular (T1) and mid-portion (T2) respectively, compared to Group B at the same locations. The statistical analysis showed a significant difference in the tunnel diameter change between the two groups at F2 (P = 0.02), T1 (P = 0.008), and T2 (P = 0.04). This study found that patients who underwent all-inside ACLR (Group A) had similar functional outcomes to those who underwent conventional ACLR (Group B). However, "tunnel diameter changes were overall more favourable in the all-inside group, particularly on the femoral side".

Background: Anterior Cruciate Ligament (ACL) reconstruction is a common orthopaedic procedure, the success of which is ultimately affected by the graft healing process. Quantification of graft healing can be performed non-invasively, using signal-intensity (SI) or signal noise quotient (SNQ) on MRI, however, the variable factors affecting graft healing are still being studied. Objectives: To non-invasively evaluate the normal morphology of the ACL graft on MRI and assess factors affecting graft healing post-arthroscopic ACL reconstruction. Method: A single-centre cross-sectional study was performed using MRI scans for assessment of the ACL graft at 6 months to 2 years post-surgery. Signal noise quotient was correlated with tibial tunnel diameter, femoral tunnel diameter, tibial tunnel location (antero-posterior and medio-lateral), femoral tunnel location (high-low and deep-shallow), graft bending angle (GBA) and notch volume. Results: Twenty-four of 42 patients had normal grafts (mean ± standard deviation post-operative time: 10.15 ± 4.38 months). The SNQ levels were highest at the proximal part of the graft. Graft SNQ correlated positively with tibial (p = 0.020) and femoral (p ≤ 0.001) tunnel diameters, tibial tunnel location in the medio-lateral direction (P ≤ 0.001), femoral tunnel location in the high-low direction (p ≤ 0.001) and patients having complications. Graft SNQ correlated negatively with tibial tunnel location in the antero-posterior (AP) direction (p ≤ 0.001). Univariate analysis revealed a significant correlation between SNQ and tibial and femoral tunnel diameter, tibial tunnel location in both AP and medio-lateral directions, femoral tunnel location in high-low direction and patients having complications. Multivariate analysis showed the tibial tunnel location (medio-lateral) and the femoral tunnel location (high-low) as the significant independent factors. Conclusion: Intraoperative factors, predominantly the positions of the tibial and femoral tunnels, are the major factors affecting graft healing. Contribution: This study provides greater awareness regarding the factors affecting graft healing, helps establish MRI as an effective non-invasive post-operative imaging modality, and helps surgeons in providing a better individualised approach to surgery.

IntroductionThere are two traditional methods of femoral tunnel drilling during anterior cruciate ligament reconstruction (ACLR), transtibial (TT) or anteromedial portal (AM). However, both these approaches have specific disadvantages. Recently, a new technique combining the advantages of both approaches while avoiding their drawbacks has been developed, hybrid transtibial (HTT). The aim of the present study was to compare the radiology of the HTT and AM techniques in patients undergoing ACLR.MethodsWe retrospectively analysed the three-dimensional computed tomography data of 31 patients who underwent ACLR (HTT and AM) at our institution between 29 October 2019 and 6 February 2023. The distance between the actual bone tunnel position and the standard anatomical location was measured in both the anterior–posterior and superior–inferior directions and expressed as a percentage. The spatial graft bending angle between the tibial and femoral tunnels was evaluated using Mimics software.ResultsThirty-one patients were included in the study: 12 and 19 in the AM and HTT groups, respectively. Compared with the AM group (9.71 ± 3.96, 9.37 ± 3.41), the HTT group had significantly smaller percentage distances t% (4.54 ± 2.76) in the anterior and posterior directions, and percentage h% (6.84 ± 2.66) in the upward and downward directions (P = 0.0002, P = 0.0281). The bending angles of the grafts in the AM and HTT groups were 103.79 ± 8.49 and 115.22 ± 9.72, respectively (P = 0.002), and the AM composition angle was more pronounced.ConclusionsThe HTT technique exhibits superior repeatability in femoral tunnel drilling compared to the AM technique, facilitating more consistent achievement of the optimal graft bone tunnel position. Moreover, the graft bending angle observed with the AM technique is more pronounced than with HTT, which likely increases the forces exerted on the graft at the shallow edge of the tunnel aperture.

Abstract Background Anterior cruciate ligament (ACL) reconstruction technique has continued to evolve over time. From the early 1990s, orthopedic surgeons performed arthroscopic ACL reconstruction using a transtibial technique. However, latter studies demonstrated that the transtibial technique is unable to locate the femoral tunnel (FT) in the native ACL femoral footprint and results in unsatisfactory clinical outcomes. Subsequently, anatomical ACL reconstruction using the tibial tunnel independent technique became the most utilized technique for FT placement at the anatomical footprint. Aim of the Work to compare clinical outcomes and graft failure after anatomical single-bundle ACLR with FT placed at different positions. Patients and Methods We performed a comprehensive literature search of the following databases from their inception dates to July 2024: PubMed, Cochrane Central Register of Controlled Trials [CENTRAL], and Web of Science. Searches were carried out in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses). The full search strategy is (anterior cruciate ligament [MeSH Terms] OR ACL[Title/Abstract]) AND (femoral tunnel[Title/Abstract] OR femoral aperture[Title/Abstract]) Results This systematic review compared the outcomes of femoral tunnel (FT) positions in anatomical single-bundle ACL reconstruction using tibial independent (TI) techniques. Seven studies involving 1,051 patients were included, comparing anteromedial bundle (AMB) with posterolateral (PLB) and central positions. While there were no significant differences in patient-reported outcomes or sagittal knee laxity between AMB and other positions, a subclinical difference of 3-4 points in Lysholm and IKDC scores favored AMB. Rotational stability was assessed clinically without instrumental evaluation, and the lack of long-term follow-up limited conclusions on complications like osteoarthritis (OA). The Lachman and pivot-shift tests were used to assess knee stability, focusing on grade 0 as normal to avoid controversy over mild grade 1 findings. Despite the limited quality of included studies, this review provides a comprehensive analysis, highlighting the need for higher-quality trials in the future. The review is the first to specifically compare FT positions in anatomical ACL reconstruction using TI techniques, contrasting with previous studies that often compared anatomical with non- anatomical placements, particularly when using the transtibial (TT) approach. The search was extensive but limited to English-language studies, potentially introducing publication bias. Conclusion Placement of FT at AMB position likely reduces the risk of failure/revision than placement at the central position. Placement of FT at AMB position achieved better anterior stability than placement at either the PLB or the central position with subclinical difference. These is no evidence of difference in patient-reported outcomes and rotational stability by pivot shift test between the three FT positions.