Search Results (213)

This study evaluated fracture risk associated with varying trochlear groove depth-to-patellar thickness (D/T) ratios in toy and small-breed dogs using finite element analysis and cadaveric mechanical testing. Finite element models derived from computed tomography data of a 4.5-kg toy poodle were adjusted to simulate D/T ratios ranging from 0.5 to 2.0 and analyzed for von Mises stress, principal strain, safety factor, and fatigue life under standing, trotting, and jumping conditions. Increasing D/T ratios led to progressive rises in stress and compressive strain, with the safety factor falling below 1.0 during jumping at ratios of 1.0 or higher. Fatigue life declined sharply beyond a ratio of 1.25 and reached zero-cycle failure at 2.0. Complementary mechanical testing of six distal femurs (6.42–8.7 kg), surgically modified to D/T ratios of 0.5, 1.0, or 1.5, revealed fracture patterns consistent with finite element predictions. These findings suggest that excessive trochlear deepening may compromise femoral integrity and elevate fracture risk, particularly under cyclic loading. Maintaining a D/T ratio between 0.75 and 1.0 may provide an optimal balance between effective patellar tracking and mechanical safety. Full article

Background: Regional periarticular bone mineral density may influence fixation and survivorship in total knee arthroplasty, but its relationship to coronal alignment remains unclear. This study assessed the association between coronal knee alignment and osteoporosis using CT Hounsfield Unit (HU)-based thresholds. Methods: Patients aged ≥ 50 years with standing long-leg radiographs and phantomless knee-CT (2008–2025) were retrospectively identified. Exclusion criteria included >12 months between studies, incomplete CT, non-120 kV acquisition, prior fracture or surgery, or metabolic bone disease other than osteopenia or osteoporosis. Mean trabecular attenuation was measured over 15 mm of epiphyseal bone in the distal femur and proximal tibia. Osteoporosis was defined using CT-HU thresholds. Coronal alignment was measured using hip–knee–ankle angle (HKAA) and categorized as varus (<178°), neutral (178–182°), or valgus (>182°). Measurements were performed by a reviewer blinded to osteoporosis classification. Multivariable logistic regression adjusted for age, sex, body mass index, and Kellgren–Lawrence grade. Results: Among 306 patients (mean age 66.9 ± 9.0 years; 51.3% female), 99.3% underwent CT for arthroplasty planning. Osteoporosis prevalence was 34.3% of varus, 58.2% of neutral, and 68.6% of valgus knees. Increasing valgus alignment was associated with higher osteoporosis odds, whereas varus alignment showed lower odds. Female sex (OR 3.06; p < 0.001), age (OR 1.06/year; p < 0.001), and HKAA (OR 1.05/degree; p = 0.042) remained independently associated with osteoporosis, whereas Kellgren–Lawrence grade was nonsignificant. Conclusions: Coronal alignment was associated with CT-defined regional knee osteoporosis. Valgus alignment showed increased odds of osteoporosis, whereas varus alignment showed lower prevalence. 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

A 46-year-old woman presented with persistent right knee pain and swelling six months after a fall. MRI initially showed a lateral meniscus tear, leading to meniscus repair and later meniscectomy, but symptoms persisted. Retrospective review of the MRI revealed edema in the tibial plateau and distal femoral condyle. Arthroscopic debridement demonstrated severe synovitis, marked cartilage loss of the lateral femoral condyle with a loose body, and tibial plateau cartilage damage. Bone SPECT/CT showed bony destruction, cleft formation, and focal tracer uptake in the distal femur and proximal tibia. Femoral osteochondritis dissecans and a tibial osteochondral defect were diagnosed based on arthroscopic and imaging findings. Full article

Background: Megaprosthetic reconstruction is the standard of care for limb salvage after tumor resection around the knee, but the full burden of unplanned revision surgery is rarely reported as a structured composite outcome. We evaluated 241 consecutive patients over 21 years at a tertiary orthopedic oncology center. Methods: This retrospective cohort included 241 patients (160 distal femur, 78 proximal tibia, three combined) treated between 2003 and 2024. Revision-free survival (RFS, composite of any unplanned revision or amputation) and amputation-free survival were estimated by Kaplan–Meier analysis; independent predictors were identified by Cox regression. A pre-specified major-event composite (amputation, implant removal, or recurrence resection) was used for sensitivity analysis. Results: Mean age was 34.9 ± 19.5 years; mean follow-up was 120.2 months. Negative resection margin (R0) was achieved in 85.5% (206/241). Unplanned revision was required in 25 patients (10.4%); overall limb salvage was 92.9%. Five-year RFS was 73.8% (distal femur) vs. 65.0% (proximal tibia; p = 0.084), and 5-year limb salvage was 88.9% vs. 84.3% (p = 0.081). Surgical margin was strongly associated with outcome: 5-year RFS 75.4% (R0) vs. 48.7% (R1/R2; p < 0.001); 5-year limb salvage 90.6% vs. 71.5% (p = 0.003). On exploratory multivariate Cox analysis, proximal tibia site and positive margin were associated with worse revision-free survival; within the proximal tibia subgroup, absence of gastrocnemius flap coverage was also associated with worse outcome (interpreted with caution given the small flap subgroup, n = 11, and limited event count). Conclusions: In this single-center series, megaprosthetic reconstruction around the knee achieved acceptable revision-free survival and limb salvage. Surgical margin status was the strongest independent predictor of both endpoints, reinforcing the well-established importance of oncologic margin quality and site-specific soft tissue strategies. Full article

Hexapod robots are attractive for operation in cluttered and uneven environments, but their walking stability is strongly affected by the coupled effects of leg morphology and foot-end trajectory planning. In many existing designs, leg-segment proportions, reachable workspace, and swing-phase trajectory smoothness are considered separately, which makes it difficult to clarify how structural parameters and motion planning jointly influence locomotion stability. To address this issue, this study presents a spider-leg-inspired hexapod robot with a simplified three-degree-of-freedom leg configuration. Selected functional characteristics of spider legs, including segmented limb structure and compliant distal contact, were abstracted into an engineering-feasible hexapod platform rather than directly reproducing spider anatomy. A parametric workspace analysis was conducted under a fixed total leg length to compare six candidate femur-to-tibia ratios. Based on forward reach, vertical foot-lifting capability, stride potential, and structural compactness, a 4:6 femur-to-tibia ratio was selected. In addition, an eleventh-order Bézier curve was developed for swing-phase foot trajectory planning and compared with a conventional composite cycloid trajectory under identical tripod-gait conditions. Simulation and straight-line walking experiments showed that the Bézier-based trajectory reduced body-attitude fluctuation and produced smoother angular-velocity variation than the composite cycloid trajectory. The results indicate that the proposed structural design and Bézier-based trajectory can improve flat-ground walking stability of the hexapod robot. This work provides a practical reference for biomimetic structural design and gait-trajectory optimization of multi-legged robots, while further validation on more complex terrain remains necessary. Full article

Background/Objectives: In periarticular knee surgery, such as osteotomies, ligament reconstruction, and fracture fixation, surgeons face a dilemma: ensuring the safety of the popliteal artery (PA) while securing adequate surgical access to the bone. While macroscopic anatomical studies suggest knee flexion protects the PA, they often fail to account for physiological muscle tension in living knees. This study aimed to quantitatively evaluate the dynamic positional changes in the PA and the vastus medialis and lateralis muscles (VM and VL, respectively) using Open Magnetic Resonance Imaging (MRI) to determine the optimal limb position for each surgical step. Methods: Twenty-three living knees were evaluated using Open MRI. The shortest perpendicular distances from the posterior aspect of the femur and tibia to the PA, and from the femoral cortex to the posterior border of the VM and VL, were measured at 10° knee-flexed position (representing the extended position) and 90° knee-flexed position. Results: The PA shifted significantly away from the bone in 90° knee-flexed position compared to extension at the distal femur (0 and 1 cm proximal to the intercondylar line (Blumensaat’s line)) and the proximal tibia (0, 1, and 2 cm distal to the joint line) (Q < 0.05). Conversely, both the VM and VL moved significantly closer to the femur in flexion at all measured levels (0–4 cm) (Q < 0.05), often causing the muscles to compress tightly against the bone. Conclusions: The vascular safety margin is maximized in flexion, whereas surgical exposure for the distal femur is optimized in extension due to vastus muscle relaxation. We suggest performing superficial exposure and femoral plate insertion in extension, and surgical maneuvers involving the posterior cortex in flexion to minimize neurovascular and soft tissue complications. Full article

Purpose: To evaluate the accuracy and precision of both femoral and tibial bone resections in unrestricted kinematic alignment total knee arthroplasty (uKA TKA) performed with manual instrumentation, using postoperative digital caliper measurements. Methods: A retrospective study analyzing prospectively collected data on femoral and tibial resection thickness in 73 patients undergoing primary uKA TKA. Femoral cuts were performed with manual KA-optimized instrumentation in all cases. Tibial cuts were performed manually in 58 cases and with patient-specific instrumentation (PSI) in 15; PSI tibial resections were excluded from tibial analyses. Postoperatively, resection thickness was measured using a digital vernier caliper (0.2 mm resolution) at predefined sites: distal medial femur (DMF), distal lateral femur (DLF), posterior medial femur (PMF), posterior lateral femur (PLF), medial tibial plateau (MTP), and lateral tibial plateau (LTP). Resection error was defined as measured minus target thickness (mm). Accuracy was reported as mean signed error; precision as SD of signed error; absolute errors and error class distributions were also reported. Postoperative measurements reflect the accuracy and precision of the initial manual tibial resections, excluding any subsequent corrective cuts. Results: A total of 408 measurements were analyzed (292 femoral, 116 tibial). Mean signed error across resections was low and consistently negative (−0.15 to −0.31 mm), with infra-millimetric precision (SD 0.45 to 0.73 mm). Mean absolute errors remained low across sites (0.35 to 0.62 mm). The proportion of errors outside ±0.5 mm ranged from 21.1% (PLF) to 44.4% (LTP) and those outside ±1.0 mm from 1.4% (DMF) to 18.5% (LTP). No errors exceeded ±2.0 mm. Conclusions: Manual caliper-verified unrestricted KA TKA achieved high accuracy and precision for both femoral and tibial resections. However, these findings do not establish superiority over other techniques and do not account for final implant position, soft-tissue balance, or clinical outcomes. This study provides quantitative data on tibial resection accuracy in uKA TKA and may serve as a benchmark for evaluating the performance of technology-assisted techniques. Full article

Background/Objectives: A floating hip injury, defined as an ipsilateral fracture of the pelvis or acetabulum combined with a femoral fracture, represents a rare and devastating musculoskeletal injury resulting from high-energy trauma. Although Müller type A floating hip injuries comprising an acetabular fracture with an ipsilateral femoral fracture are recognized for their clinical complexity, the long-term prognostic factors influencing functional outcomes remain poorly elucidated. This study aimed to identify independent prognostic factors associated with unsatisfactory long-term functional outcomes in patients with Müller type A floating hip injuries. Methods: A retrospective study was performed on 68 consecutive patients with Müller type A floating hip injuries who underwent surgical fixation at a single tertiary trauma center, with a minimum follow-up period of 5 years. Functional outcomes were assessed using the Majeed score, and patients were dichotomized into satisfactory (n = 48; 70.6%) and unsatisfactory (n = 20; 29.4%) outcome groups. Acetabular fractures were classified according to the Judet–Letournel system, and femoral fractures were classified by fracture level (proximal, shaft, or distal). Radiological outcomes were evaluated using Matta’s radiological grading system. Demographic, injury-specific, and treatment-related variables were compared between groups using the Mann–Whitney U test and chi-square test with Bonferroni correction. A multivariate binary logistic regression model was constructed to determine independent predictors of unsatisfactory outcomes. Results: The mean age was 37.15 ± 12.07 years, with a male predominance (67.6%). The predominant mechanism of injury was pedestrian struck by vehicle (54.4%), followed by motor vehicle collision (27.9%) and fall from height (17.6%); collectively, high-energy vehicular trauma accounted for 82.3% of cases. In the univariate analysis, transverse with posterior wall acetabular fracture pattern (p = 0.001), proximal femur fracture level (p = 0.001), associated lower extremity fractures (p = 0.001), nerve damage (p = 0.001), higher body mass index (BMI) (p = 0.001), and lower Matta’s radiological scores (p = 0.001) were significantly associated with unsatisfactory outcomes. Three independent predictors emerged in the multivariate logistic regression: BMI (OR = 1.50; 95% CI: 1.05–2.15; p = 0.025), the presence of associated lower extremity fractures (OR = 29.02; 95% CI: 2.83–297.67; p = 0.005), and Matta’s radiological score (OR = 0.06; 95% CI: 0.01–0.56; p = 0.014). The model yielded internal discriminatory metrics within the acceptable range (overall accuracy 89.7%, sensitivity 95.8%, specificity 75.0%, Nagelkerke R² = 0.757); however, given the limited events-per-variable ratio (~6.7) and the wide confidence intervals observed for some predictors, these internal performance estimates are likely optimistic due to potential overfitting, and the findings should be interpreted as exploratory pending external validation. Conclusions: Elevated BMI, the presence of associated ipsilateral lower extremity fractures, and poor quality of acetabular reduction, assessed via Matta’s radiological criteria, are independent determinants of unsatisfactory long-term functional outcomes in Müller type A floating hip injuries. These findings underscore the critical importance of achieving anatomical reduction in the acetabulum and highlight the compounding effect of additional ipsilateral limb injuries on patient prognosis. Full article

Background: Distal femur fractures remain among the most challenging injuries in orthopedic trauma, particularly in elderly or osteoporotic patients and in cases involving periprosthetic or highly comminuted distal femur fracture patterns. Modern fixation strategies include retrograde intramedullary nails, locking plates, and, more recently, combined nail–plate constructs (NPC). However, the optimal fixation method remains debated, and high-quality comparative evidence is limited. This systematic review evaluates clinical outcomes, union rates, and complications associated with single versus combined fixation constructs in distal femur fractures. Materials and Methods: A systematic review was performed according to PRISMA guidelines using PubMed/MEDLINE, EMBASE, and the Cochrane Database up to June 2025. Original studies reporting surgical management of distal femur fractures, including periprosthetic distal femur fractures, with postoperative outcomes were included. Ten retrospective studies met the inclusion criteria, comprising 397 patients. Methodological quality was assessed using the Modified Coleman Methodology Score (mean: 56.5). Data collected included patient demographics, fracture type, surgical technique, union rates, complications, and follow-up duration. Descriptive statistics were used to summarize trends due to study heterogeneity. Results: Among the included fractures, 304 involved the distal femur and 55 were periprosthetic. Combined nail–plate fixation was used in 203 patients, while 185 received single-implant fixation. Across studies, union rates were consistently higher in the NPC group, with several reporting 100% union, compared with more variable results in single-construct cohorts (72–96.7%). The most frequent complication in the NPC group was infection (12 cases), whereas delayed union predominated in single-implant constructs (19 cases). Patient comorbidities, such as diabetes or smoking, were inconsistently reported but may have influenced complication patterns. Follow-up periods ranged from 5.15 to 20 months, and operative details were included in several studies. Due to heterogeneity and retrospective design, no meta-analysis was performed, but descriptive trends were consistently observed. Conclusions: Nail–plate constructs appear to offer mechanical advantages in complex or high-risk distal femur fractures, achieving superior union rates compared with single implants. However, this benefit is counterbalanced by a higher incidence of postoperative infections, likely related to greater surgical invasiveness. Single constructs remain appropriate for simpler fracture configurations or better-quality bone. High-quality prospective research with standardized radiographic and functional outcomes is needed to clarify indications and optimize fixation strategies for distal femur fractures. Full article

Background/Objectives: Although unrestricted kinematic alignment (uKA) has gained increasing acceptance in total knee arthroplasty (TKA), its application in knees with lateral compartment osteoarthritis (OA) remains a subject of debate due to concerns over postoperative gap imbalance and alignment outliers. The purpose of this study was to evaluate the surgical, radiographic, and clinical outcomes of contralateral non-OA knee–referenced, caliper-verified uKA in lateral compartment OA. Methods: This retrospective study included 40 patients with isolated lateral compartment OA who underwent primary TKA using contralateral non-OA knee–referenced, caliper-verified uKA. Surgical outcomes were assessed by measuring bone resection thicknesses of the distal femur, posterior femur, and proximal tibia, as well as extension and 90° flexion gaps. Radiographic outcomes included mechanical hip–knee–ankle angle, medial proximal tibial angle, lateral distal femoral angle, and Coronal Plane Alignment of the Knee (CPAK) classification. Patient-reported outcomes (PROs), including Pain VAS, EQ-5D, satisfaction, and Forgotten Joint Score, were assessed at a minimum follow-up of 2 years. Results: The resected osteochondral thickness was consistently greater on the medial side than on the lateral side, and all gap balances were well maintained, with a gap difference ≤ 2 mm observed in 95% of knees in full extension. Postoperatively, restoration to the same CPAK category was achieved in approximately 90% of cases. All PROs improved and reached levels comparable to those of the contralateral knee. Conclusions: In patients with lateral compartment OA, caliper-verified uKA may be appropriately applied when guided by a reliable anatomic reference, such as the contralateral non-OA knee. This strategy achieves stable soft-tissue balance, reliable coronal alignment restoration, and favorable clinical outcomes in carefully selected valgus knees undergoing TKA. Full article

Background/Objectives: Successful cementless total knee arthroplasty (TKA) requires adequate bone quality. However, reliable tools for intraoperative assessment remain limited. This study aimed to introduce a novel visual grading system for evaluating femoral bone during surgery and to assess its correlation with actual bone mechanical properties and suitability for cementless fixation. Methods: We prospectively recruited 193 patients receiving posterior-stabilized TKA. Intraoperatively, femoral cutting surfaces were classified into four visual grades (Excellent, Good, Fair, Poor) considering pore appearance and contour integrity. Femoral bone specimens were harvested during box preparation, and bone mechanical properties were measured through indentation testing. Spearman correlation was used to evaluate the relationship between visual grades and bone mechanical properties. Fisher’s exact test was used to evaluate the distribution pattern of cementless suitable and cemented mandatory classifications across visual grading. Receiver operating characteristic (ROC) analysis was used to evaluate diagnostic accuracy for each visual grade cutoff. Results: Visual grade strongly correlated with bone mechanical properties (Spearman’s ρ = 0.881, p < 0.01). Cementless suitable cases were predominantly distributed in Good/Excellent visual grades, while cemented mandatory cases were mostly found in Fair/Poor grades. However, 8% of Good visual grade specimens exhibited strength warranting cemented fixation, and 18% of Fair visual grade specimens demonstrated adequate mechanical properties for cementless fixation. Using the Good visual grade as a cutoff threshold, ROC analysis showed excellent diagnostic accuracy (AUC = 0.941) with high sensitivity (89%) and specificity (94%). Conclusions: The authors’ novel intraoperative visual assessment system demonstrated significant correspondence to measured bone mechanical properties in the distal femur and showed high accuracy in determining suitability for cementless TKA in Asian individuals. Given the ethnic homogeneity of this cohort, further validation in diverse populations is required to generalize these findings. Full article

Background/Objectives: Juvenile osteochondritis dissecans (JOCD) of the knee is commonly treated using conservative or joint-preserving surgical techniques. While clinical outcomes are generally favorable, the risk of early cartilage degeneration remains unclear. Joint space width (JSW) on weight-bearing radiographs serves as an indirect marker of cartilage health. Artificial intelligence (AI)-based JSW assessment may enable sensitive and reproducible detection of early degenerative changes. Methods: This cross-sectional feasibility study included 21 skeletally immature patients treated for JOCD of the distal femur between 2002 and 2017. Treatment modalities comprised conservative management, retrograde drilling, and fragment refixation. Fully automated JSW measurements were performed on standardized anteroposterior knee radiographs using a validated AI-based software IB Lab KOALA™, Version 2.4. JSW of the affected compartment was compared with the contralateral knee and between treatment groups. Clinical outcomes were assessed using the Lysholm Knee Scoring Scale and the International Knee Documentation Committee (IKDC) score. Additionally, a systematic review of the literature on post-treatment degenerative changes following OCD therapy was conducted according to PRISMA guidelines. Results: Compared with manually reviewing images, the software IB Lab KOALA™, Version 2.4 as easy to implement. AI-based analysis revealed no significant differences in JSW between the affected and contralateral knees, nor between treatment modalities. Average JSW exceeded 6 mm in all groups after a median follow-up of 64 (min. 27, max. 177) months. Clinical scores were high and comparable across treatments. A moderate positive correlation was observed between the JSW and Lysholm score, while increasing age and longer follow-up were associated with a reduced JSW. The systematic review identified ten relevant studies, reporting generally favorable long-term clinical outcomes with a low but present risk of osteoarthritis progression. Conclusions: Our AI-based analysis showed no differences in JSW between conservative and joint-preserving surgical treatments of JOCD in the follow-up. This technology can provide a valuable tool for standardized and sensitive radiographic monitoring in young patients. Full article

The pathogenesis of primary osteoarthritis (OA) is complex and multifactorial. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a transcription factor that regulates hundreds of genes involved with cytoprotection. The role of Nrf2 in OA remains undefined. We utilized the Hartley guinea pig model of primary OA to investigate the role of a purported Nrf2 activator, PB125, in delaying the onset of knee OA. We hypothesized that three months of daily PB125 supplementation would modify structural, molecular, and in vivo functional outcomes characteristic of disease. Fifty-six 2-month-old animals (equal sexes) were treated orally with PB125 or vehicle control for 3 months; animals were sacrificed at 5 months, which represents mild OA and early disease. Outcome measures included knee histopathology, mRNA expression, immunohistochemistry, and in vivo mobility. Notably, PB125 treatment had differing effects in males and females. Female PB125-treated animals had significantly decreased distal femur OA scores, accompanied by differential gene and protein expression patterns in articular cartilage for markers related to redox homeostasis; decreases in one compulsory mobility metric were also seen. In contrast, males demonstrated a statistical difference in voluntary mobility patterns. In summary, PB125 may modify the molecular mechanisms involved in the initiation of early OA in a potential sex-dependent fashion. Full article

Background and Objectives: The aim of this study was to compare the clinical and radiological outcomes of the nail-plate combination (NPC) and double-plate (DP) fixation techniques in revision surgery performed after fixation failure of periprosthetic distal femur fractures. Materials and Methods: Patients who underwent revision surgery for periprosthetic distal femur fractures following fixation failure between 2018 and 2023 at a tertiary referral center were retrospectively reviewed. Based on the surgical technique, patients were divided into two groups: NPC group (n = 27) and DP group (n = 45). Demographic characteristics, operative time, intraoperative blood loss, and fluoroscopy time were recorded. Radiological evaluation included union time, while clinical outcomes were assessed with the Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Short Form-36 (SF-36) health survey. Complications (infection, thromboembolism, implant failure, nonunion, malalignment), reoperation, and 1-year mortality rates were also analyzed. Results: The NPC group had significantly shorter operative time (107 vs. 134 min, p < 0.001) and lower intraoperative blood loss (412 vs. 634 mL, p < 0.001). Hospital stay was shorter in the NPC group (6.9 ± 1.5 vs. 10.2 ± 3.3 days, p < 0.001). Mean union time was approximately three weeks shorter in the NPC group (15.4 vs. 18.8 weeks, p < 0.001). Functional outcomes (KSS, WOMAC, SF-36) did not differ significantly between groups. Complication rates were comparable; implant failure was the most frequent complication (NPC: 3.7% vs. DP: 13.3%). One-year mortality did not differ significantly (NPC: 7.4% vs. DP: 11.1%). Conclusions: Compared with DP fixation, the NPC technique offers clear perioperative advantages in revision surgery performed after fixation failure of periprosthetic distal femur fractures, including shorter operative time, reduced blood loss, and faster union. Functional outcomes and complication rates were similar between techniques. These findings suggest that the NPC may represent a safer and more feasible alternative. Full article