Search Results (31)

Background/Objectives: Meniscal tears frequently occur during athletic activities and are often associated with anterior cruciate ligament injuries. The purpose of this study was to compare the posterior tibial slope (PTS) in young adults undergoing arthroscopic surgery for isolated meniscal tears with that of a control group, and to investigate its association with meniscal tears. Methods: This retrospective, single-centre, controlled study included 190 patients aged 18–30 years who presented with unilateral knee pain and underwent knee magnetic resonance imaging (MRI) between 2015 and 2022. Patients with an isolated medial meniscal tear (Group A, n = 67) or an isolated lateral meniscal tear (Group B, n = 31), confirmed on MRI and directly with arthroscopy, were compared with a symptomatic control group who presented with knee pain but had no meniscal or anterior cruciate ligament (ACL) tear on MRI (Group C, n = 92). Medial and lateral PTS angles were measured on pre-existing standing lateral knee radiographs. Interobserver and intraobserver reliability were quantified using intraclass correlation coefficients (ICCs). Group comparisons, receiver operating characteristic (ROC) analysis with the Youden index, and multivariable binary logistic regression adjusted for age, sex and side were performed. Results: Both medial and lateral PTS angles were significantly higher in Groups A and B than in the control group (p < 0.05). ROC analysis identified a cut-off of 9.2° for the medial PTS in the medial-tear group (AUC: 0.756, 95% CI: 0.68–0.83; sensitivity: 64.18%, specificity: 80.43%) and 9.9° for the lateral PTS in the lateral-tear group (AUC: 0.709, 95% CI: 0.60–0.82; sensitivity: 58.06%, specificity: 81.52%). The association persisted after adjustment for age, sex and side (medial slope in medial tears adjusted OR: 1.36 per 1°, 95% CI: 1.19–1.55, p < 0.001; lateral slope in lateral tears adjusted OR: 1.25 per 1°, 95% CI: 1.08–1.44, p = 0.003). Conclusions: In this retrospective cohort of young adults, an increased posterior tibial slope was associated with isolated meniscal tears. A medial PTS greater than 9.2° and a lateral PTS greater than 9.9° were associated with medial and lateral meniscal tears, respectively. Given the modest sensitivity and the observational design, PTS should be regarded as a supportive morphological marker rather than a stand-alone diagnostic metric, and a causal relationship cannot be inferred based on the results of this study. Because discrimination was only fair (AUC 0.693–0.756) and sensitivity limited (54.8–64.2%), these cut-offs are not clinically applicable decision thresholds and should be used only in conjunction with clinical assessment and MRI. Full article

Background: Anterior cruciate ligament reconstruction (ACLR) is a common orthopedic procedure with generally favorable outcomes, yet graft failure remains a significant challenge, particularly in young and active patients. While various anatomical and biomechanical risk factors for graft failure have been proposed, the influence of the sagittal tibial tubercle–trochlear groove (sTTTG) distance, representing anterior–posterior alignment of the tibial tubercle, has not been sufficiently explored. This study aimed to evaluate the association between sTTTG and ACL graft failure and assess contributing biomechanical variables, including tibiofemoral rotation (TFR), posterior tibial slope (PTS), and knee flexion angle. Methods: For this secondary analysis, a retrospective matched case–control study was conducted, involving 151 patients with ACL graft failure who underwent revision ACLR and 151 controls with intact grafts after a minimum 2-year follow-up period. sTTTG was measured on axial MRI as the anteroposterior distance from the trochlear groove to the tibial tubercle, perpendicular to the posterior femoral condylar axis. Secondary measurements included TT-TG, TFR, medial and lateral PTS, and knee flexion angle. Group differences as well as factors predictive of sTTTG were analyzed. Results: The ACLR failure group demonstrated a significantly lower sTTTG distance compared to controls (0.5 ± 4.6 mm vs. 2.4 ± 4.8 mm, p = 0.001). Logistic regression analysis revealed that a 1 mm increase in sTTTG was associated with an 8% reduction in revision risk (OR = 0.93 per 1 mm increase; 95% CI, 0.88–0.97; p = 0.003), although the predictive accuracy was low (AUC = 0.6). Multivariable analysis identified lateral PTS and knee flexion as significant independent predictors of sTTTG. Conclusions: A decreased sTTTG distance was significantly associated with ACL graft failure, underscoring the relevance of sagittal tibial tubercle positioning in ACL biomechanics. While not an independent clinical decision-making tool, sTTTG appears relevant to graft failure and may be considered in future risk assessment strategies. Full article

Purpose: Posterior tibial slope (PTS) is an important anatomical parameter that influences knee kinematics and clinical outcomes following total knee arthroplasty (TKA). Recent advances in CT-based robotic-assisted TKA (RA-TKA) have enabled accurate three-dimensional (3D) evaluation of knee morphology. However, limited data are available regarding PTS and its associated coronal and sagittal alignment factors in Asian patients with knee osteoarthritis. The purpose of this study was to quantify medial and lateral PTS and to identify alignment factors associated with PTS, thereby clarifying the relevance of individualized 3D assessment for TKA planning. Methods: This retrospective study evaluated 236 knees from 236 Asian patients with knee OA undergoing primary RA-TKA (MAKO^®, Stryker, Kalamazoo, MI, USA). Radiological parameters, including medial posterior tibial slope (MPTS), lateral posterior tibial slope (LPTS), medial proximal tibial angle (MPTA), lateral distal femoral angle, mechanical hip–knee–ankle angle, arithmetic hip–knee–ankle angle, and femur flexion angle were automatically calculated by MAKO planning software based on predefined anatomical landmarks and reference axes. Correlation and multivariate regression analyses were performed to assess the relationships between PTS and other coronal, sagittal alignment parameters. Results: The cohort showed an overall varus tendency, with a mean mechanical HKA angle of −8.3° ± 5.21°, while coronal alignment itself was not used as an exclusion criterion. PTS demonstrated substantial variability among individuals as well as between the medial and lateral sides within the same knee. The distribution of PTS values showed a wide range, with MPTS ranging from −4.8° to 24.5° and LPTS ranging from −1.4° to 17.4°. The MPTS was significantly greater than the LPTS (7.85° ± 4.72° vs. 6.33° ± 4.04°, p < 0.001). No statistically significant association was observed between MPTS and MPTA. Multivariate linear regression demonstrated that LPTS was the strongest positive predictor of MPTS (β = 0.365, p < 0.001), while height (β = −0.169, p = 0.006) and femoral flexion angle (β = −0.195, p < 0.001) were significant negative predictors. Conclusions: In Asian patients with knee OA, PTS showed substantial inter-individual variability and significant medial–lateral asymmetry on 3D CT analysis. These findings suggest that a fixed PTS target may not fully reflect patient-specific native morphology, and further outcome-based studies are needed to define the optimal compartment-specific PTS reference for TKA planning. Full article

Unicompartmental knee arthroplasty (UKA) is an effective treatment for anteromedial osteoarthritis in carefully selected patients. Increasing attention has recently been directed toward restoration of pre-arthritic coronal alignment, supported by the use of the arithmetic hip–knee–ankle angle (aHKA) to estimate constitutional lower limb alignment. In medial UKA, kinematic alignment principles derived from the original technique described by Cartier et al. may help to reproduce native joint-line orientation while preserving physiological soft-tissue balance. This technical note details the indications, preoperative assessment, planning strategy, and operative steps of the procedure. Preoperative long-leg weight-bearing radiographs are used to estimate constitutional alignment through the aHKA and to plan the coronal inclination of the tibial cut. Intraoperatively, the distal position of the extramedullary guide is reproduced according to the preoperative planning in order to restore the native inclination of the medial tibial plateau. The sagittal tibial cut, posterior tibial slope, distal femoral cut, component sizing, gap assessment, and cementation technique are described, with emphasis on anatomical landmarks and technical pearls to improve reproducibility. The described technique provides a practical method for approximating constitutional coronal alignment in medial UKA without the use of robotic or navigated systems. The key feature of the procedure is accurate planning and execution of the tibial cut in both the coronal and sagittal planes in order to reproduce native joint-line orientation and preserve appropriate ligament balance. Full article

Background: Revision anterior cruciate ligament reconstruction (ACLR) presents an increasing clinical challenge with higher failure rates than primary reconstruction. However, the evolving research landscape and clinical evidence regarding key biomechanical risk factors remain incompletely synthesized. Methods: A sequential dual methodological approach was applied. First, a bibliometric analysis of the Web of Science Core Collection was performed to map global research trends and identify emerging hotspots. Based on the identified hotspot, a PRISMA-compliant meta-analysis of studies retrieved from PubMed, Embase, the Cochrane Library, and Web of Science was subsequently conducted. Clinical and radiographic outcomes were synthesized using random-effects models in R. Results: The bibliometric analysis included 4213 publications and demonstrated exponential growth in revision ACLR research, identifying posterior tibial slope (PTS) as the dominant research hotspot. A meta-analysis of 11 studies involving 299 patients showed significant postoperative improvements in patient-reported outcomes and objective knee stability measures, along with a mean PTS reduction of 8.72° (95% CI 7.84–9.60; p < 0.001), while no significant change in patellar height was observed. The pooled return-to-sport rate was 74% (95% CI 64–82%), and the most common complications were symptomatic hardware and postoperative recurvatum. Conclusions: PTS has emerged as a key focus in revision ACLR research, and addressing this biomechanical factor may be associated with improved functional and radiographic outcomes. However, current evidence is mainly derived from retrospective studies, and further prospective research is needed to confirm long-term efficacy and refine surgical indications. Full article

Background/Objective: Accurate assessment of the posterior tibial slope (PTS) is essential for optimal alignment and kinematic restoration in unicompartmental knee arthroplasty (UKA). This study aimed to evaluate the accuracy of three commonly used radiographic PTS measurement techniques—the anterior tibial cortex (ATC), tibial proximal anatomical axis (TPAA), and posterior tibial cortex (PTC)—by comparing them with the intraoperatively achieved tibial resection slope, using digital volume tomography (DVT) of intraoperative tibial resectates as an executed resection reference. Methods: In this retrospective study, 39 patients undergoing medial UKA were analyzed. Standardized lateral knee radiographs were used to measure the complement angle β using ATC, TPAA, and PTC reference axes. Intraoperatively obtained tibial resectates were scanned using DVT to provide a high-resolution three-dimensional reference. The conventional posterior tibial slope was defined as α (PTS) = 90° − β (measured angle). Agreement and systematic bias between radiographic and DVT measurements were assessed using Wilcoxon signed-rank tests and Bland–Altman analyses. Results: The mean DVT-derived β was 86.48° ± 1.62° (α 3.52°). ATC 79.69° ± 3.14° (α 10.31°) and TPAA 82.50° ± 2.95° (α 7.50°) yielded significantly lower β values than DVT (both p < 0.0001), whereas PTC (86.24° ± 2.51°; α 3.76°) showed no significant difference (p = 0.419). Bland–Altman analyses demonstrated minimal bias for PTC (−0.25°) compared with larger negative biases for ATC (−6.79°) and TPAA (−3.99°) (negative bias indicates lower β and therefore higher conventional posterior tibial slope α). Conclusions: Among the evaluated methods, the PTC technique most accurately reflects the intraoperatively achieved tibial resection slope when benchmarked against DVT measurements. Incorporating the PTC method into preoperative planning may improve the radiographic estimation and standardization of the achieved tibial cut in UKA. Further studies should assess its impact on clinical outcomes and explore integration into automated measurement workflows. Full article

Background: Posterior cruciate ligament reconstruction (PCLR) remains one of the most technically demanding procedures in knee ligament surgery, with complication rates considerably higher than those observed for other arthroscopic procedures. Residual laxity, arthrofibrosis, neurovascular injury, tunnel-related complications, and heterotopic ossification (HO) represent the most frequent adverse events. With increasing surgical volumes and complexity—particularly in multiligament knee injuries (MLKIs)—structured, evidence-based strategies for complication avoidance are essential. The objective of this review is to provide a comprehensive, evidence-based overview of the main complications associated with PCLR and to propose a structured, reproducible protocol for complication prevention integrating current literature and high-volume institutional experience. Methods: A narrative review of the literature was conducted using PubMed and Google Scholar to identify clinical, biomechanical, and systematic studies on PCLR complications published between 2010 and 2025. Overall, 58 studies were screened and 33 were included for qualitative synthesis. Among the included studies, the level of evidence was Level I in five systematic reviews/meta-analyses, Level III–IV in seven observational clinical studies and registries, and Level V in biomechanical studies, narrative reviews, and expert consensus reports. In parallel, the recommendations were informed by the cumulative experience of a high-volume tertiary referral center with 187 PCLR procedures performed between 2010 and 2025 (136 MLKI, 51 isolated). Results: Evidence identifies several key predictors of postoperative complications: low posterior tibial slope (<6.54°), small graft diameter (<7.0 mm), untreated posterolateral corner insufficiency, excessive tibial tunnel angle, and surgical trauma at the “killer turn.” Neurovascular complications primarily arise during tibial tunnel instrumentation, with knee hyperflexion (>90°) significantly improving safety. Suture tape augmentation (STA) reduces graft elongation by 45–58% and is associated with improved biomechanical stability without increasing complication rates. Early controlled motion is critical to prevent arthrofibrosis, whereas HO—affecting up to 45% of MLKI patients—requires delayed surgical excision after maturation. Conclusions: Optimal outcomes after PCLR derive from a structured, complication-focused approach encompassing anatomical risk assessment, meticulous tunnel planning, neurovascular protection, biological augmentation, and disciplined postoperative rehabilitation. Adoption of standardized protocols—particularly in MLKIs—can substantially reduce the incidence of adverse events and improve long-term knee stability. Full article

Objectives: Medial open-wedge high tibial osteotomy (MOWHTO) is a surgical procedure used to treat medial compartment osteoarthritis of the knee with varus deformity. The aim of this study was to examine whether a larger correction angle in medial open wedge high tibial osteotomy (MOWHTO) leads to greater changes in postoperative patellar height (PH) and posterior tibial slope (PTS). Methods: Data from 83 patients who underwent MOWHTO were retrospectively analyzed. Lower limb alignment was evaluated using the hip–knee–ankle angle (HKAA). The PH was assessed using the Insall–Salvati index (ISI), the Blackburne–Peel index (BPI), the Caton–Deschamps index (CDI), the modified Miura–Kawamura index (MKI), and the plateau–patella angle (PPA). The PTS was determined using the Moore–Harvey method. Results: The median correction of HKAA was 8°. A decrease in PH was observed in the majority of cases across all methods, with the highest frequency of postoperative patella infera detected using the MKI. PTS most frequently increased, with a median increase of 3°. A significant association between the magnitude of HKAA correction and patellar height in the overall cohort was observed only for the MKI, whereas in patients with an HKAA correction ≥ 10°, significant associations were found for both the MKI and CDI. No significant association was found between the magnitude of HKAA correction and changes in posterior tibial slope in the overall cohort, while a significant negative correlation was observed in patients with an HKAA correction ≥ 10°. Conclusions: Assessment using the MKI demonstrated greater sensitivity in detecting postoperative PH decrease, particularly in identifying patella infera. The magnitude of HKAA correction was significantly associated with greater changes in PTS and PH in patients with a coronal plane correction of ≥10°. Full article

Background: Total knee arthroplasty (TKA) effectively relieves pain in end-stage osteoarthritis, yet a proportion of patients remain dissatisfied despite advances in surgical technique. Medial-congruent (MC) bearings are designed to recreate native medial-pivot kinematics, which depend on appropriate medial compartment soft tissue tension. Robotic-assisted TKA (RA-TKA) has been shown to improve the accuracy and soft tissue balance. However, evidence of its additional benefits in MC TKA remains limited. Methods: We retrospectively identified consecutive primary TKAs with the same MC bearing performed between April 2022 and June 2024 at a tertiary center. After performing 1:1 propensity score matching to reduce baseline imbalance, 36 patients who received RA-TKA and 36 who underwent manual TKA (M-TKA) were included. Primary outcomes were evaluated with the 12-month Oxford Knee Score (OKS) and KOOS-JR. Secondary outcomes included radiographic alignment parameters, outlier rates, operative time, liner thickness, and hospital stay. Results: Baseline characteristics and liner thickness were comparable, and operative time was longer in the RA-TKA group than in the M-TKA group. Both RA-TKA and M-TKA produced significant 12-month improvements in OKS and KOOS-JR with no difference in mean scores. RA-TKA had fewer posterior tibial slope outliers (mean slope 4.3° ± 1.8 vs. 5.9° ± 3.1; outlier rate 16.7% vs. 41.7%; p = 0.02), whereas coronal alignment parameters did not differ between groups. Conclusions: RA-TKA with MC bearing provides functional outcomes comparable to M-TKA and may decrease sagittal alignment variability; long-term follow-up studies are needed to determine whether this potential benefit translates into sustained functional gains or improved implant survivorship. Full article

Background/Objectives: Posterior tibial slope (PTS) is an established risk factor for anterior cruciate ligament (ACL) injury in adults. In pediatric population, this relation is less established, and the PTS measurement is not clearly defined. To determine the agreement between X-ray (XR) and magnetic resonance imaging (MRI) PTS measurements and to establish an MRI cutoff corresponding to the standard radiographic ≥12° definition of “high slope”. Methods: In this retrospective study, 108 adolescent knees with ACL rupture underwent paired XR and MRI evaluation by two reviewers. Agreement was assessed with Pearson and Spearman correlation, intraclass correlation coefficient (ICC), Bland–Altman analysis, and Deming regression. Diagnostic performance of MRI thresholds was compared with XR ≥ 12° as reference. Results: Mean PTS was higher on XR (10.2 ± 3.1°) than on MRI (8.4 ± 2.8°), with a systematic bias of +1.8° revealed by Bland–Altman analysis. These two measurements showed strong positive correlation (r = 0.602, p < 0.001) and moderate concordance (ICC = 0.506, 95% CI, 0.186–0.696, p = 0.0015). Individual differences ranged up to ±5° between modalities. Using XR ≥ 12° as reference for “high slope,” ROC analysis identified an optimal MRI cutoff of 8.8° with excellent diagnostic accuracy (AUC = 0.841, 95% CI, 0.760–0.922). Conclusions: Radiographic measurements systematically overestimate PTS relative to MRI. Numeric thresholds are not interchangeable between modalities. An MRI cutoff of approximately 9° corresponds to the radiographic ≥12° definition of high slope and may serve as a pragmatic reference for interpreting MRI-based measurements in pediatric patients, requiring further validation. Full article

Introduction: This case report presents the multifactorial surgical management and long-term outcome of a permanent patellar dislocation in a 16-year-old female patient. Case presentation: A 16-year-old female with permanent patellar dislocation of the left knee complained of progressive pain and functional limitations. Physical examination revealed a 20-degree passive flexion contracture, significant muscle weakness in knee extension, and a permanently laterally dislocated patella that could not be manually repositioned. Imaging studies revealed a complex knee deformity characterised by femoral valgus, tibial varus, posterior tibial slope, and trochlear dysplasia. The patient underwent a comprehensive surgical approach addressing all deformities, including femoral and tibial osteotomies, trochleoplasty, medial patellofemoral ligament (MPFL) plasty, and quadriceps muscle balancing. Results: At the eight-year follow-up, the patient demonstrated a full range of motion and adequate stability, and experienced mild pain only rarely. Outcomes improved significantly: the International Knee Documentation Committee (IKDC) score increased from 10.3% to 75.9%, the Lysholm score rose from 24 to 72, the Kujala score improved from 22 to 67, and the BPII score increased from 14.9 to 55.4. Conclusions: Comprehensive surgical correction of all predisposing factors achieved sustained functional improvement over eight years, demonstrating that systematic treatment of anatomical and functional abnormalities is essential for the successful management of permanent patellar dislocation. Level of evidence: V. Full article

Background: Robotic-assisted systems have transformed total knee arthroplasty (TKA), promising improved accuracy and intraoperative consistency, yet real-world data from non-academic centers remain limited. Objective: This study evaluates five-year clinical integration of a semi-autonomous, CT-based, robotic-arm-assisted TKA at a tertiary non-teaching hospital in Germany, focusing on planning accuracy, gap balancing, and intraoperative outcomes. Methods: We retrospectively analyzed all patients (n = 457) who underwent MAKO-assisted TKA from 2020 to 2025, performed by three orthopedic surgeons using a standardized subvastus approach. We assessed preoperative deformities, intraoperative alignment, implant sizing, and gap balancing. Surgical plans were adapted intraoperatively when indicated. Pre- vs. post-implantation values were compared using slopes to evaluate execution consistency. Results: Median patient age was 67.0 years (IQR: 60.0–75.0), with varus in 84.1% (7.0°, IQR: 4.0°–10.0°), valgus in 13.2% (3.0°, IQR: 1.5°–5.8°), and neutral alignment in 2.7%. Flexion contracture occurred in 80.4% (6.0°, IQR: 3.0–10.0%), hyperextension in 12.7% (2.0°, IQR: 1.5°–5.0°). Planning-to-execution consistency was high, even with plan adaptations. Slope values for alignment parameters were: tibial rotation in degrees (slope value: 1.0), femoral sagittal angle in degrees (0.8), tibial sagittal angle in degrees (0.9), coronal posterior condylar angle in degrees (0.9), femoral component size (1.0), tibial component size (1.0). Over 95% of cases showed ≤3.0° deviation between planned and final values. Bone resection concordance showed moderate agreement, with slopes from 0.8 (posterior medial femoral cut in mm) to 0.5 (lateral tibial cut in mm). Gap balancing improved at all stages, with reduced variability in medial/lateral extension and flexion gaps (all p < 0.05). Functional reconstruction showed significant improvements in extension, flexion, and deformities (all p < 0.001). Conclusions: Semi-autonomous, CT-based, robotic-arm-assisted TKA was successfully implemented in this non-academic setting, demonstrating acceptable intraoperative and functional reconstruction outcomes, supporting the feasibility of robotic-assisted surgery outside academic centers. Full article

Background and Objectives: The relationship between posterior tibial slope (PTS) and isolated meniscal injuries remains a topic of debate. This study aimed to investigate whether an increased PTS was associated with a higher risk of isolated meniscal tears, using a case-control design with propensity score matching to minimize confounding factors. Materials and Methods: A retrospective case-control study was conducted at a University Hospital. A total of 294 patients who underwent arthroscopic surgery for meniscal injuries were compared to a matched control group without documented knee pathology. Two independent observers measured PTS on standardized lateral knee radiographs and assessed inter- and intra-rater reliability. Propensity score matching was performed to control for potential confounders. Statistical analysis included logistic regression to evaluate the association between PTS and isolated meniscal injuries. Results: A significantly increased mean PTS was observed in patients with isolated meniscal injuries compared to controls (p < 0.05). However, PTS was not significantly associated with the specific location of meniscal tears. Inter- and intra-rater reliability for PTS measurements was excellent (intraclass correlation coefficient > 0.75). Conclusions: An increased posterior tibial slope was associated with a higher risk of meniscal injury, even in the absence of ACL rupture. However, no significant association was found between PTS and specific tear patterns or locations. These findings support the role of posterior tibial slope as an independent anatomical risk factor for meniscal damage and underscore the importance of its early identification in clinical risk assessment and prevention strategies. Full article

Background/Objectives: Total knee arthroplasty (TKA) is the gold-standard treatment for advanced knee arthritis, offering pain relief and improved joint function. However, tibial component malalignment, malrotation, and improper biomechanical loading remain critical factors contributing to implant failure, instability, and revision surgeries. This review systematically examines the impact of biomechanical loading on the tibial insert following primary TKA, with a focus on alignment, posterior tibial slope (PTS), and load distribution. Methods: A systematic literature search was conducted across the PubMed, Google Scholar, and Web of Science databases following the PRISMA guidelines. Studies investigating the effects of tibial component alignment, varus/valgus deviations, PTS, and load distribution on tibial inserts post-TKA were included. Seven studies meeting the inclusion criteria were analyzed and described narratively. Results: The reviewed studies highlighted that varus and valgus malalignment significantly alter tibiofemoral contact pressures and ligament strains, increasing the risk of aseptic loosening and implant failure. Excessive PTS was associated with posterior femoral translation, altered ligament tension, and increased contact stresses on polyethylene (PE) inserts. Kinematically aligned TKA demonstrated reduced tibial force imbalances and improved functional outcomes compared to mechanically aligned TKA. Computational and cadaveric studies revealed that even minor malalignments (e.g., 3° varus or valgus) can cause significant biomechanical changes. Conclusions: Biomechanical loading on tibial inserts after primary TKA is highly sensitive to the alignment and PTS. Optimal alignment and controlled biomechanical forces are essential. Kinematically aligned TKA has shown promising effects, preventing aseptic loosening and ensuring long-term implant survival. Further in vivo studies are needed to validate these findings and optimize surgical techniques. Full article

Background/Objectives: Lateral extraarticular tenodesis (LET) has been advocated in revision anterior cruciate ligament reconstruction (ACLR) to improve knee stability and furthermore, decrease failure rates. The aim of this study was to compare clinical outcomes, knee laxity, and failure rates after revision ACLR with LET (ACLR + LET) versus without LET. It was hypothesized that ACLR + LET improves clinical outcomes and reduces the failure rate. Methods: A retrospective analysis of prospectively collected data was conducted to examine patients who underwent revision ACLR with and without LET between 2017 and 2021 with a minimum follow-up of 24 months. Patients with coronal malalignment (>5°), posterior tibial slope >12°, and concomitant injuries to collateral ligaments were excluded. Patient reported outcome measures (PROMs) included the International Knee Documentation Committee (IKDC) subjective knee score, the Lysholm score, and the Tegner activity scale (TAS). Anterior knee laxity was measured with a Rolimeter and side-to-side difference (SSD) was determined. Revision ACLR failure was defined as ACL revision surgery and SSD > 5 mm. Group comparisons were performed using chi-square-, independent-samples students t-test or Mann–Whitney–U tests. Results: Of 56 eligible patients, 45 (80%, follow up, 23 isolated rACLR vs. 22 rACLR + LET) were included with a mean follow-up of 45.6 ± 15.8 months. Postoperative PROMs were not statistically different between rACLR and rACLR + LET groups (IKDC: 73.0 ± 18.9 vs. 68.7 ± 16.6, n.s.; Lysholm: 84.8 ± 12.3 vs. 77.7 ± 16.2, n.s.). Both groups showed similar TAS (rACLR vs. rACLR +LET (5; range 4–6 vs. 4; range 3–5; n.s.). Anterior knee laxity SSD was 2.4 ± 1.3 mm in the rACLR group and 1.8 ± 1.8 mm in the rACLR + LET group (n.s.). The failure rate was 13% in the rACLR group compared to 4.5% in the rACLR + LET group (n.s.). Conclusions: Isolated revision ACLR showed comparable postoperative patient-reported outcome measures and anterior knee laxity compared to ACLR + LET at mid-term follow up. The addition of a LET demonstrated a lower, though non-significant, failure rate after revision surgery. However, future studies with a prospective, randomized design and an increased number of patients are needed to clearly identify the exact indication for the use of additional LET. Full article