BACKGROUND:Preoperative templating supports total knee arthroplasty (TKA) planning, and AI-assisted tools are increasingly used to improve component-size estimation. However, the magnitude of improvement in exact femoral and tibial component-size prediction compared with conventional templating has not been quantitatively synthesized. We aimed to compare the accuracy of AI-assisted preoperative templating with conventional techniques in predicting exact implanted prosthesis size. METHODS:PubMed (MEDLINE), Scopus, Web of Science, and the Cochrane Library were searched from inception to November 2025. Eligible studies included patients undergoing primary TKA in whom AI-assisted preoperative templating predicted exact femoral and/or tibial component size and was compared with conventional templating. Risk of bias was assessed using RoB 2 and ROBINS-I. RESULTS:Eight studies were included. In implanted-size-restricted analyses, AI-assisted templating did not significantly improve exact femoral component-size prediction (risk ratio (RR) 1.38; 95% confidence interval (CI) 0.92-2.08; P = 0.09; 95% prediction interval 0.63-3.04), whereas tibial prediction was borderline significant (RR 1.38; 95% CI 1.01-1.89; P = 0.05; 95% prediction interval 0.76-2.49). Computed tomography (CT)-based AI-assisted planning was associated with higher exact femoral and tibial prediction accuracy than conventional radiographic templating, while radiograph-based AI analyses were inconclusive. Short-term functional scores at 3 months after surgery showed no significant between-group differences. CONCLUSION:CT-based AI-assisted templating may improve exact component-size prediction in primary TKA. However, prediction intervals crossed the null, indicating uncertainty regarding the consistency and magnitude of benefit. The apparent advantage may reflect combined effects of three-dimensional imaging and AI-assisted planning rather than AI alone. Evidence regarding radiograph-based AI planning and postoperative benefit remains inconclusive.
PURPOSE:Integrin α10β1 is a collagen type II-specific receptor selectively expressed on chondrocytes and has demonstrated therapeutic relevance in mesenchymal stem cell (MSC)-based cartilage repair. However, its functional significance in terminally differentiated chondrocytes remains unclear. This study aimed to evaluate whether enrichment of α10β1⁺ (CD11c⁺CD29⁺) chondrocytes improves chondrogenic capacity and cartilage repair potential in-vitro and in an ex-vivo human osteochondral unit (OCU) model. METHODS:Chondrocytes isolated from human osteoarthritic cartilage were subjected to FACS to enrich CD11c⁺CD29⁺ subpopulations. Sorted and unsorted chondrocytes were evaluated for chondrogenic marker expression (SOX9, ACAN, COL2A1), hypertrophic markers (COL10A1, RUNX2), and matrix production (GAG/DNA, type II collagen ELISA). Functional outcomes were further assessed in an ex-vivo PRP-embedded chondral defect repair model using histology, immunohistochemistry, and modified Wakitani scoring. RESULTS:Compared to unsorted cells, α10β1⁺ chondrocytes exhibited modest changes in surface marker expression but no consistent improvement in gene expression of chondrogenic or hypertrophic markers. Histological, biochemical, and immunohistochemical analyses of pellets and OCUs showed comparable outcomes between groups. Type II collagen deposition and repair scores were not significantly different, and matrix organization remained immature in all conditions. CONCLUSION:α10β1 enrichment did not confer a regenerative advantage in chondrocytes, likely due to their lineage commitment and limited phenotypic plasticity. Unlike in MSCs, integrin-based sorting alone may be insufficient in mature chondrocytes. Scaffold-based strategies or combinatorial markers may be required to enhance outcomes in cartilage repair applications.
Purpose To systematically synthesize the literature dedicated to discoid medial meniscus (DMM) and to describe its clinical presentation, imaging and arthroscopic features, morphology, associated pathology, management, outcomes, and temporal reporting patterns. Methods PubMed/MEDLINE, Scopus, and Web of Science were searched through 24 June 2026. Original human reports of radiologically or intraoperatively confirmed classic DMM with extractable clinical, imaging, treatment, or outcome data were eligible. Reports limited to discoid lateral meniscus, nonclinical anatomical studies, reviews without unique cases, duplicate cohorts, or without separable DMM data were excluded. Data were synthesized descriptively with variable-specific denominators; quality was assessed using design-appropriate JBI or MINORS tools. Results Ninety reports described 179 patients/cases and 241 DMM knees; 117/164 were male (71.3%). Bilateral DMM was reported in 62/149 patients (41.6%), complete morphology in 103/151 knees (68.2%), and tears in 149/196 knees (76.0%). Surgery was reported in 180/241 knees (74.7%): rim-preserving procedures in 142/180 operated knees (78.9%), total meniscectomy in 29 (16.1%), repair in 34 (18.9%), and allograft transplantation in 3 (1.7%). Contemporary reports more often described MRI, rim preservation, and repair than historical reports. Conclusions Evidence consisted predominantly of case reports and small series. Bilateral involvement, complete morphology, and tears were frequently reported, while contemporary literature more often described MRI, arthroscopy, and meniscal preservation. These are published-literature patterns, not population estimates or comparative evidence of treatment effectiveness. Standardized multicenter or registry-based studies are needed. Level of evidence Level V, systematic review of Level IV-V evidence.
BACKGROUND:Previous literature has identified non-modifiable risk factors for anterior cruciate ligament (ACL) rupture and patellofemoral instability (PFI), such as sex, joint laxity, tibial slope, variations in the intercondylar notch, patella alta, trochlear dysplasia, distance from the tibial tubercle to the trochlear groove, and posterior cruciate ligament morphology. The primary aim of this study was to compare femorotibial rotation among pediatric patients with ACL rupture, PFI, and a comparison cohort. The authors hypothesized there would be differences in femorotibial rotation measurements between patients with ACL rupture, PFI, and a comparison cohort. METHODS:A retrospective review was conducted, where patients aged 8-21 years at a single institution who sustained an ACL rupture or PFI injury between January 2015 and August 2022 were identified. Participants were included if they had a preoperative EOS lower limb x-ray. Participants with a history of previous knee surgery to either knee, or more than one diagnosis of either ACL rupture or PFI were excluded. Participants were compared to a cohort of scoliosis patients with a Cobb angle less than 20° who had biplane EOS radiographs (Controls). All preoperative radiographs were sent for EOS three-dimensional reconstructions. Data outputs with a specific focus on femorotibial rotation, femoral anteversion, and tibial torsion were acquired and analyzed. The femorotibial rotation output measurements were positive or negative, representing external and internal rotation, respectively. A Kruskal-Wallis Test was run to compare femorotibial rotation between the three groups (ACL, PFI, Controls), and pairwise comparisons were also analyzed. Statistical significance was set to p ≤ 0.05. Univariate and multivariable linear regression analyses were performed to assess the association between femorotibial rotation and group, age, sex, BMI, and mechanical axis alignment. RESULTS:Of the identified patients, 197 met final inclusion and exclusion criteria (60 ACL, 92 PFI, 45 Controls). The mean age at time of imaging for all patients was 14.4 ± 2.2 years (ACL: 14.3 ± 1.8 years; PFI: 14.3 ± 2.4 years; Controls: 14.9 ± 2.4 years), and 50.8% were female (ACL: 43.3% female; PFI: 58.7% female; Controls: 44.4% female). The median femorotibial rotation was 4.8° (ACL: -2.1°; PFI: 10.2°; Controls: 4.4°). Femorotibial rotation was noted to be significantly different between cohorts (p < 0.001), and the pairwise comparisons between each group were also significant (ACL-Control: p < 0.001, ACL-PFI: p < 0.001, Control-PFI: p < 0.001). These differences remained significant after multivariable adjustment for age, sex, BMI, and mechanical axis alignment (ACL vs. Control: p < 0.001; PFI vs. Control: p = 0.001). CONCLUSIONS:Femorotibial rotation differed significantly between patients with ACL rupture, PFI, and a comparison cohort. Most ACL patients had internal femorotibial rotation, while most PFI patients had external femorotibial rotation.
BACKGROUND:Patellofemoral pathology is multifactorial with increasing evidence suggesting that tibiofemoral rotation (TFR) contributes to pain, maltracking and recurrent instability. Reported TFR values vary considerably because of differences in imaging modality, acquisition protocol, axial slice selection and reference axes. The aim of this review is to analyse the literature available on tibiofemoral rotation in patellofemoral pathology. METHODS:A PRISMA-compliant systematic review of PubMed/MEDLINE, Embase and Scopus was performed up to May 2026. Studies assessing TFR in patellofemoral instability or resultant anterior knee pain were included. Data regarding imaging modality, measurement technique, reference axes, normative and pathological values, interaction with tibial tubercle indices, and clinical relevance were extracted and synthesised qualitatively. RESULTS:Twenty-five studies were included, predominantly retrospective observational Level III studies. MRI was used in nine studies, CT alone in eight, and both modalities in four. Reference-group mean TFR values ranged from 3.8° internal to 5.7° external rotation, whereas pathological cohort means ranged from 1.6° to 12° external rotation. Where full participant ranges were reported, values overlapped substantially between healthy participants (-8.7° to 11.7°) and patellofemoral-instability cohorts (-6.5° to 21.6°). Increased external TFR was associated with patellar maltracking, recurrent instability and rotational effects on TT-TG interpretation; however, reported values were dependent on imaging modality, reference-axis definition and knee position. CONCLUSION:Current evidence supports an association between increased external tibiofemoral rotation and patellofemoral pathology, although methodological standardisation remains necessary before TFR can be reliably incorporated into routine clinical decision-making.
INTRODUCTION:With robotic-assisted precision, total knee replacement (TKR) alignment has regained attention to address 20% post-operative dissatisfaction. While coronal alignment has been studied extensively, the impact of axial alignment on patient-reported outcome measures (PROMs) remains unclear. METHODS:Five databases were searched (to 15/02/2025). Random-effects meta-regression models, weighted by number of TKRs, assessed associations between each axial alignment parameter and PROMs. Analyses were conducted using individual PROMs and then with all PROMs combined as standardised-mean-differences(SMD), at individual timepoints, pooled, and time-adjusted levels. RESULTS:Sixty-five studies were included (n = 8392 TKRs, 8113 patients). Most (86%) studies reported only one or two axial parameters, with fewer than half assessing more than one and measurement protocols varied widely. Greater external femoral-component-rotation (FCR, range: -2.60° to 2.63°) improved Knee-Society-Score (KSS)-Overall (Regression-Coefficient (RC) = 33.2, p < 0.001, n = 323) and KSS-Function (RC = 11.5, p < 0.001, n = 327) at 12 months, and Standardised-Mean-Difference(SMD) PROM scores (RC = 3.38, p = 0.042, n = 1112). Higher external tibial-component-rotation (TCR, range: -4.30° to 19.0°) improved KSS-Function at 12 months (RC = 1.90, p = 0.030, n = 234), Western-Ontario-and-McMaster-Universities-Arthritis-Index (WOMAC)-Total in pooled/time-adjusted analyses (RC = - 4.62/-4.57, p < 0.001, n = 2221), and SMD PROMs at 3 months (RC = 0.57, p < 0.001, n = 149). Lower mismatch-rotation (MR) improved SMD PROM in pooled/time-adjusted analysis (RC = -0.55/-0.52, p < 0.001, n = 786, MR Range: -10.5°-9.30°). Combined-rotation (CR) showed no significant individual timepoint, pooled or time-adjusted effects on PROMs or SD PROMs. CONCLUSION:This review provides an up-to-date quantitative synthesis demonstrating that higher FCR, higher TCR, and lower MR, are associated with improved PROMs, emphasising the importance of considering axial alignment alongside coronal plane in TKR. However, heterogeneity in measurement protocols, underreporting of parameters limit comparability and generalisability. Standardised, multiplanar reporting is essential to establish evidence-based alignment targets and guide surgeons in optimising patient outcomes.
INTRODUCTION:Osteochondral allograft (OCA) transplantation can be performed through an open or arthroscopic approach, yet comparative data on early safety are scarce. This study compares 30-day complications after open versus arthroscopic knee OCA using a national database and identifies independent risk factors for adverse events. METHODS:The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried for all patients undergoing elective knee OCA procedures from 2010 to 2023. Adults with complete perioperative data were included. One-to-one nearest-neighbor propensity score matching was used to control for baseline differences between cohorts. Of 2087 cases meeting inclusion criteria, 2078 (1165 open, 913 arthroscopic) remained after 9 patients with concurrent billing for both codes were excluded, and 1826 of these patients were included in the final propensity-matched analysis (913 per group). Thirty-day complications, defined by any adverse event (AAE) and resource-utilization metrics, were compared with Wilcoxon rank-sum or chi-square testing. Separate multivariable logistic regressions identified predictors of AAE within each cohort. RESULTS:Two thousand seventy-eight patients were initially identified, with 1165 (56%) undergoing open OCA and 913 (44%) undergoing arthroscopic OCA. After matching, 913 patients remained in each group. Open surgery was associated with a longer mean operative time (124.9 min vs.101.9 min, p < 0.001; median [IQR] 108 [77-152] vs.90 [61-126] minutes) and a greater mean length of stay (0.60 days vs.0.28 days, p < 0.001; median [IQR] 0 [0-1] vs.0 [0-0] days), differences that probably reflected the fact that larger or more complex lesions were more often treated with the open approach, as was the case for the greater overall burden of concomitant procedures, rather than being attributable to the approach itself. Open OCA was also associated with higher odds of overnight hospital admission compared with arthroscopic OCA (OR 2.99, 95% CI 2.34-3.81, p < 0.001). Thirty-day AAE rates were similarly low between cohorts (2.3% for open vs 2.2% for arthroscopic). No deaths, myocardial infarctions, strokes, or pneumonia occurred. Rates of individual complications (surgical-site infection, thromboembolism, transfusion, unplanned reoperation) were <1% with no between-group differences. DISCUSSION & CONCLUSION:Knee OCA transplantation is exceptionally safe in the early postoperative period, with complication rates below 3% and no statistically significant difference in complications between open and arthroscopic techniques. Open procedures are associated with greater resource utilization, specifically longer operative time and length of stay, most likely reflecting their use for larger or anatomically complex lesions rather than an inherent difference in safety between approaches. In the open cohort, smoking is the principal modifiable risk factor for short-term morbidity and should be a focus of perioperative optimization. These findings support selecting surgical approaches based on lesion size, location, and technical considerations rather than concerns about early complications.
PURPOSE:Robotic arm-assisted total knee arthroplasty (R-TKA) enables precise bone resection and real-time intraoperative gap adjustment, facilitating functional alignment (FA). However, performing FA with standardized implants may cause unintended changes in the joint line (JL), and their clinical relevance remains unclear. This study aimed to evaluate the association between compartment-specific JL changes and postoperative patient-reported outcomes after R-TKA with FA. METHODS:This retrospective study included 147 knees that underwent primary cruciate retaining (CR) R-TKA with FA. JL height was defined as the perpendicular distance from the transepicondylar axis to the most distal aspect of the femoral condyles on preoperative and postoperative computed tomography images. Patients were categorized into elevation, neutral, or depression groups based on a 2-mm deviation from the native JL in the medial and lateral compartments. Patient-reported outcomes were measured 1 year after surgery. RESULTS:Mean JL depression occurred in both compartments, with a greater change in the lateral compartment (3.1 ± 2.5 vs. 1.8 ± 2.5 mm). Among the groups in the medial compartment, the elevation group had the lowest Forgotten Joint Score-12 scores (mean difference = 28.5 points, Cohen's d = 1.09). In contrast, lateral JL changes were not significantly associated with 1-year patient-reported outcomes. Final gap asymmetry values were comparable among medial JL subgroups. CONCLUSION:Although JL depression was relatively well tolerated, medial JL elevation was associated with worse 1-year patient-reported outcomes after CR R-TKA with FA. These findings suggest that unnecessary medial JL elevation may warrant caution, whereas modest JL depression may be acceptable when needed to achieve balanced gaps.
BACKGROUND:Chronic periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is a severe complication causing repeated surgeries and reduced quality of life. When revision is not feasible due to bone loss, extensor mechanism deficiency, or persistent infection, knee arthrodesis (KA) can be a limb-salvage alternative to amputation. This study evaluates functional outcomes, infection control, and patient satisfaction after KA using a cemented modular intramedullary nail (IMN) in chronic PJI after TKA. METHODS:This retrospective cohort included patients treated with floating KA using a cemented IMN within a two-stage protocol for chronic PJI between 2016 and 2023. Demographic and clinical data, walking ability, use of aids, and residential status were collected. Quality of life was assessed with Short Form-12 (SF-12) physical (PCS) and mental (MCS) scores. Correlation analyses identified factors associated with outcomes. RESULTS:Fifteen patients were included (mean age 74.4 ± 9.5 years; mean follow up 36 months). No septic recurrence or mechanical failure occurred. Eleven patients (73.3%) were satisfied, and all preferred KA over amputation. Most remained ambulatory with aids and lived independently. Younger age correlated with higher SF-12 PCS (P = 0.02), while more previous surgeries correlated with lower SF-12 MCS (P = 0.046). Taller patients showed lower satisfaction (P = 0.005). CONCLUSION:Floating KA with a cemented modular IMN is a reliable limb-salvage option for chronic PJI after failed TKA, ensuring infection control, mechanical stability, and acceptable quality of life. Psychological well-being influences satisfaction and should be considered in preoperative counseling to guide preoperative counseling and decisions.
BACKGROUND:Medial pivot total knee arthroplasty (MP-TKA) prioritizes medial stability while allowing a degree of lateral laxity. Traditional mechanical alignment may enlarge the lateral gap, but whether such laxity compromises dynamic coronal stability during weight-bearing gait remains unclear. METHODS:Consecutive patients who underwent mechanically aligned MP-TKA were prospectively enrolled, and fluoroscopic gait analysis using 3D-2D registration was performed to evaluate coronal alignment and joint stability during the mid-stance phase of gait. Intraoperative soft-tissue balance was quantified using standardized gap measurements in both extension and flexion. Dynamic coronal stability was assessed using femoral-tibial implant varus-valgus angle (VVA), mediolateral displacement (MLD) between the implants, and the presence of femoral condylar lift-off (FCLO). Forty knees were analyzed. RESULTS:Although lateral laxity exceeded medial laxity intraoperatively in both extension and flexion, coronal alignment during the mid-stance phase of gait remained neutral (mean hip-knee-ankle angle 180.8 ± 2.7°, VVA 0.0 ± 0.3°) with minimal mediolateral translation (MLD 0.2 ± 0.5 mm). No knee demonstrated FCLO. Soft-tissue balance parameters showed no significant correlation with VVA, MLD, or tibial joint line obliquity. CONCLUSION:These findings indicate that for mechanical alignment this medial pivot design may accommodate a certain degree of lateral laxity without compromising coronal stability during the mid-stance phase of gait when medial stability is preserved.
BACKGROUND:Posterior cruciate ligament (PCL) tibial avulsion fractures may result in persistent instability and functional impairment if inadequately treated. This study aimed to evaluate the clinical and radiographic outcomes of patients with PCL tibial avulsion fractures treated using a modified anterior tension band construct. METHODS:A retrospective review was performed on 23 consecutive patients treated with open reduction and internal fixation between 2017 and 2025. Fixation was achieved using two parallel screws combined with an anteriorly tensioned cerclage wire construct. The postoperative rehabilitation protocol included early controlled range-of-motion exercises without routine brace immobilization. Clinical outcomes, radiographic union, complications, and return-to-activity outcomes were evaluated at final follow up. RESULTS:The mean follow up duration was 29.6 ± 7.4 months. All fractures achieved radiographic union without fixation failure or secondary displacement. The mean time to union was 10.8 ± 1.9 weeks. At final follow up, the mean knee flexion was 134.8 ± 5.7°. Mean Lysholm and International Knee Documentation Committee (IKDC) scores improved significantly from 43.2 ± 7.9 to 93.6 ± 4.8 and from 40.7 ± 8.4 to 91.2 ± 5.3, respectively (P < 0.001). No deep infection, neurovascular injury, or nonunion were observed. CONCLUSIONS:This retrospective case series demonstrated satisfactory clinical and radiographic outcomes after fixation of PCL tibial avulsion fractures using a modified anterior tension band construct. However, because no biomechanical testing or control group was included, the present findings should not be interpreted as evidence of superior fixation stability or added benefit over conventional screw fixation alone.
PURPOSE:Greater internal tibial rotation on magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) injury is a risk factor for graft failure after ACL reconstruction. However, the factors influencing rotational alignment on MRI remain unclear. This study aimed to examine the factors associated with tibial rotation on preoperative MRI in patients with ACL injury. METHODS:Preoperative MRI images of 214 patients with ACL injuries were retrospectively analyzed to quantify the tibiofemoral rotation angle (TFA). Injuries to the medial collateral ligament, lateral collateral ligament, anterolateral ligament, Kaplan fibers, and meniscal tears were assessed. The lateral and medial posterior tibial slopes were measured. Patients were classified into an internal rotation group (TFA ≥ 4.5°; n = 81) and an external rotation group (TFA < 4.5°; n = 133). Factors associated with increased tibial internal rotation were evaluated using logistic regression analysis. RESULTS:The mean TFA was 8.3 ± 2.5° in the internal rotation group and 0.3 ± 3.1° in the external rotation group. Lateral posterior tibial slope was significantly greater in the internal rotation group than in the external rotation group (8.3 ± 3.2° vs. 7.0 ± 2.9°, P < 0.01). Multivariable analysis identified male sex (odds ratio 1.93, P = 0.047) and greater lateral posterior tibial slope (odds ratio 1.20, P < 0.001) as independent factors associated with tibial internal rotation. CONCLUSION:In patients with ACL injury, increased tibial internal rotation on preoperative MRI was independently associated with male sex and a greater lateral posterior tibial slope.
BACKGROUND:Knee osteoarthritis (KOA) is a progressive degenerative joint disease without curative treatment. Novel knee orthoses incorporating pneumatic unloading, vibratory stimulation, and magnetic/electromagnetic fields have emerged as conservative options. This review evaluated and compared their biomechanical and clinical effects in adults with KOA. METHODS:PubMed, Web of Science, Scopus, ProQuest, and Google Scholar were searched (January 1973-December 2025). Original studies assessing pneumatic, vibratory, or magnetic/electromagnetic knee orthoses in KOA were included. Two reviewers independently screened studies, extracted data, and assessed quality using the Downs and Black checklist. A narrative synthesis was conducted due to heterogeneity. RESULTS:Eleven studies (∼300 participants) were included. Pneumatic orthoses (eight studies) reduced knee adduction moment (KAM) by 7.6-39%, improved gait, decreased pain (up to 36%, P = 0.006), and enhanced strength and function (Lower Extremity Functional Scale P = 0.001; Knee Society Score P = 0.0067). Some findings suggested delayed progression (total knee arthroplasty 18% vs. 36%; injections 46% vs. 83%, P = 0.026). One vibratory orthosis study showed a greater reduction in KAM (P = 0.016) and sustained unloading after removal. Magnetic/electromagnetic field (ELF) orthoses (two studies) mainly improved pain (P = 0.011) and Knee Injury and Osteoarthritis Outcome Scores (KOOS), with limited biomechanical effects. Study quality ranged from poor to good (13-23/27), with small samples and short follow up being common. CONCLUSION:Pneumatic orthoses show the strongest evidence for biomechanical and clinical benefits in KOA. Vibratory designs may provide neuromuscular advantages, while magnetic/ELF devices mainly offer symptomatic relief. Larger, high-quality trials are needed.
